alpha-oxo acid decarboxylase: Topics by Science.gov

Sample records for alpha-oxo acid decarboxylase

Properties of the branched-chain 2-hydroxy acid/2-oxo acid shuttle in mouse spermatozoa.

PubMed

Coronel, C E; Gallina, F G; Gerez de Burgos, N M; Burgos, C; Blanco, A

1986-05-01

Operation of the branched-chain 2-hydroxy acid/2-oxo acid shuttle for the transfer of reducing equivalents in mitochondria of mouse spermatozoa was studied in vitro in reconstituted systems. Results show that the branched-chain 2-oxo acids within the mitochondria are offered several metabolic pathways. (a) Decarboxylation: mouse sperm mitochondria possess high branched-chain 2-oxo acid decarboxylase activity. (b) Recycling to the cytosol by using a transport system which can be inhibited by alpha-cyano-3-hydroxycinnamate and pH 6.8. (c) Transamination to the corresponding amino acids: experiments presented indicate that leucine formed from 4-methyl-2-oxopentanoate may pass to the external phase, re-initiating the cycle. These two last possibilities would allow autocatalytic operation of the shuttle. The branched-chain 2-hydroxy acids apparently do not utilize the monocarboxylate carrier to penetrate the mitochondria.
Pyruvate Decarboxylase Catalyzes Decarboxylation of Branched-Chain 2-Oxo Acids but Is Not Essential for Fusel Alcohol Production by Saccharomyces cerevisiae

PubMed Central

ter Schure, Eelko G.; Flikweert, Marcel T.; van Dijken, Johannes P.; Pronk, Jack T.; Verrips, C. Theo

1998-01-01

The fusel alcohols 3-methyl-1-butanol, 2-methyl-1-butanol, and 2-methyl-propanol are important flavor compounds in yeast-derived food products and beverages. The formation of these compounds from branched-chain amino acids is generally assumed to occur via the Ehrlich pathway, which involves the concerted action of a branched-chain transaminase, a decarboxylase, and an alcohol dehydrogenase. Partially purified preparations of pyruvate decarboxylase (EC 4.1.1.1) have been reported to catalyze the decarboxylation of the branched-chain 2-oxo acids formed upon transamination of leucine, isoleucine, and valine. Indeed, in a coupled enzymatic assay with horse liver alcohol dehydrogenase, cell extracts of a wild-type Saccharomyces cerevisiae strain exhibited significant decarboxylation rates with these branched-chain 2-oxo acids. Decarboxylation of branched-chain 2-oxo acids was not detectable in cell extracts of an isogenic strain in which all three PDC genes had been disrupted. Experiments with cell extracts from S. cerevisiae mutants expressing a single PDC gene demonstrated that both PDC1- and PDC5-encoded isoenzymes can decarboxylate branched-chain 2-oxo acids. To investigate whether pyruvate decarboxylase is essential for fusel alcohol production by whole cells, wild-type S. cerevisiae and an isogenic pyruvate decarboxylase-negative strain were grown on ethanol with a mixture of leucine, isoleucine, and valine as the nitrogen source. Surprisingly, the three corresponding fusel alcohols were produced in both strains. This result proves that decarboxylation of branched-chain 2-oxo acids via pyruvate decarboxylase is not an essential step in fusel alcohol production. PMID:9546164
Transformation of bile acids into iso-bile acids by Clostridium perfringens: possible transport of 3 beta-hydrogen via the coenzyme.

PubMed

Batta, A K; Salen, G; Shefer, S

1985-01-01

We have examined the mechanism for the bacterial transformation of chenodeoxycholic acid and lithocholic acid into the corresponding 3 beta-hydroxy epimers with the use of 3 alpha- and 3 beta-tritiated bile acids. The 3-oxo bile acids were transformed into the 3 alpha- (85%) and 3 beta- (15%) hydroxy bile acids after 20-hr incubation with Clostridium perfringens. Approximately 75% radioactivity was recovered in the aqueous medium when [3 beta-3H]chenodeoxycholic acid or [3 beta-3H]lithocholic acid was incubated with the bacteria, and approximately 15% of radioactivity in the bile acid fraction was associated with the 3 alpha-position of the iso-bile acids. When [3 beta-3H]chenodeoxycholic acid was incubated with unlabeled 3-oxo-5 beta-cholanoic acid, tritiated litho- and iso-lithocholic acids were recovered. These results can be explained only when a 3-oxo intermediate is postulated, and the 3 beta-hydrogen in the bile acids is transferred by the bacterial coenzyme (NAD+ or NADP+) to the 3 alpha-position in the iso-bile acids during the reduction of the 3-oxo compounds.
Biosynthesis of o-succinylbenzoic acid in Bacillus subtilis: identification of menD mutants and evidence against the involvement of the alpha-ketoglutarate dehydrogenase complex.

PubMed Central

Palaniappan, C; Taber, H; Meganathan, R

1994-01-01

The biosynthesis of o-succinylbenzoic acid (OSB), the first aromatic intermediate involved in the biosynthesis of menaquinone (vitamin K2) is demonstrated for the first time in the gram-positive bacterium Bacillus subtilis. Cell extracts were found to contain isochorismate synthase, 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylic acid (SHCHC) synthase-alpha-ketoglutarate decarboxylase and o-succinylbenzoic acid synthase activities. An odhA mutant which lacks the decarboxylase component (usually termed E1, EC 1.2.4.2, oxoglutarate dehydrogenase [lipoamide]) of the alpha-ketoglutarate dehydrogenase complex was found to synthesize SHCHC and form succinic semialdehyde-thiamine pyrophosphate. Thus, the presence of an alternate alpha-ketoglutarate decarboxylase activity specifically involved in menaquinone biosynthesis is established for B. subtilis. A number of OSB-requiring mutants were also assayed for the presence of the various enzymes involved in the biosynthesis of OSB. All mutants were found to lack only the SHCHC synthase activity. PMID:8169214
Characterisation of a thiamine diphosphate-dependent alpha-keto acid decarboxylase from Proteus mirabilis JN458.

PubMed

Wang, Biying; Bai, Yajun; Fan, Taiping; Zheng, Xiaohui; Cai, Yujie

2017-10-01

Alpha-keto acid decarboxylases can convert keto acids to their corresponding aldehydes, which are often volatile aroma compounds. The gene encoding α-keto acid decarboxylase in Proteus mirabilis JN458 was cloned, and the enzyme overexpressed in Escherichia coli BL21 (DE3), purified in high yield, and characterised. The molecular weight is 62.291kDa by MALDI-TOF MS, and optimum activity at pH 6.0 and 40-50°C. The enzyme is a typical decarboxylase, dependent on thiamine diphosphate and Mg 2+ as cofactors. For the decarboxylation reaction, the enzyme displayed a broad substrate range. Kinetic parameters were determined using 4-methyl-2-oxopentanoic acid, phenyl pyruvate and 3-methyl-2-oxopentanoic acid as substrates. K m and k cat values for phenyl pyruvate were 0.62mM and 77.38s -1 , respectively, and the k cat /K m value was 124.81mM -1 s -1 . The enzyme properties suggest it may act effectively under cheese ripening conditions. Copyright © 2017. Published by Elsevier Ltd.
Expression and stereochemical and isotope effect studies of active 4-oxalocrotonate decarboxylase.

PubMed

Stanley, T M; Johnson, W H; Burks, E A; Whitman, C P; Hwang, C C; Cook, P F

2000-02-01

4-Oxalocrotonate decarboxylase (4-OD) and vinylpyruvate hydratase (VPH) from Pseudomonas putida mt-2 form a complex that converts 2-oxo-3-hexenedioate to 2-oxo-4-hydroxypentanoate in the catechol meta fission pathway. To facilitate mechanistic and structural studies of the complex, the two enzymes have been coexpressed and the complex has been purified to homogeneity. In addition, Glu-106, a potential catalytic residue in VPH, has been changed to glutamine, and the resulting E106QVPH mutant has been coexpressed with 4-OD and purified to homogeneity. The 4-OD/E106QVPH complex retains full decarboxylase activity, with comparable kinetic parameters to those observed for 4-OD in the wild-type complex, but is devoid of any detectable hydratase activity. Decarboxylation of (5S)-2-oxo-3-[5-D]hexenedioate by either the 4-OD/VPH complex or the mutant complex generates 2-hydroxy-2,4E-[5-D]pentadienoate in D(2)O. Ketonization of 2-hydroxy-2,4-pentadienoate by the wild-type complex is highly stereoselective and results in the formation of 2-oxo-(3S)-[3-D]-4-pentenoate, while the mutant complex generates a racemic mixture. These results indicate that 2-hydroxy-2, 4-pentadienoate is the product of 4-OD and that 2-oxo-4-pentenoate results from a VPH-catalyzed process. On this basis, the previously proposed hypothesis for the conversion of 2-oxo-3-hexenedioate to 2-oxo-4-hydroxypentanoate has been revised [Lian, H., and Whitman, C. P. (1994) J. Am. Chem. Soc. 116, 10403-10411]. Finally, the observed (13)C kinetic isotope effect on the decarboxylation of 2-oxo-3-hexenedioate by the 4-OD/VPH complex suggests that the decarboxylation step is nearly rate-limiting. Because the value is not sensitive to either magnesium or manganese, it is likely that the transition state for carbon-carbon bond cleavage is late and that the metal positions the substrate and polarizes the carbonyl group, analogous to its role in oxalacetate decarboxylase.
DOE Office of Scientific and Technical Information (OSTI.GOV)

French, Jarrod B.; Ealick, Steven E.

The stereospecific oxidative degradation of uric acid to (S)-allantoin was recently shown to proceed via three enzymatic steps. The final conversion is a decarboxylation of the unstable intermediate 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and is catalyzed by OHCU decarboxylase. Here we present the structures of Klebsiella pneumoniae OHCU decarboxylase in unliganded form and with bound allantoin. These structures provide evidence that ligand binding organizes the active site residues for catalysis. Modeling of the substrate and intermediates provides additional support for this hypothesis. In addition we characterize the steady state kinetics of this enzyme and report the first OHCU decarboxylase inhibitor, allopurinol, a structuralmore » isomer of hypoxanthine. This molecule is a competitive inhibitor of K. pneumoniae OHCU decarboxylase with a K{sub i} of 30 {+-} 2 {micro}m. Circular dichroism measurements confirm structural observations that this inhibitor disrupts the necessary organization of the active site. Our structural and biochemical studies also provide further insights into the mechanism of catalysis of OHCU decarboxylation.« less
Resolving Phenylalanine Metabolism Sheds Light on Natural Synthesis of Penicillin G in Penicillium chrysogenum

PubMed Central

Veiga, Tânia; Solis-Escalante, Daniel; Romagnoli, Gabriele; ten Pierick, Angela; Hanemaaijer, Mark; Deshmuhk, Amit; Wahl, Aljoscha; Pronk, Jack T.

2012-01-01

The industrial production of penicillin G by Penicillium chrysogenum requires the supplementation of the growth medium with the side chain precursor phenylacetate. The growth of P. chrysogenum with phenylalanine as the sole nitrogen source resulted in the extracellular production of phenylacetate and penicillin G. To analyze this natural pathway for penicillin G production, chemostat cultures were switched to [U-13C]phenylalanine as the nitrogen source. The quantification and modeling of the dynamics of labeled metabolites indicated that phenylalanine was (i) incorporated in nascent protein, (ii) transaminated to phenylpyruvate and further converted by oxidation or by decarboxylation, and (iii) hydroxylated to tyrosine and subsequently metabolized via the homogentisate pathway. The involvement of the homogentisate pathway was supported by the comparative transcriptome analysis of P. chrysogenum cultures grown with phenylalanine and with (NH4)2SO4 as the nitrogen source. This transcriptome analysis also enabled the identification of two putative 2-oxo acid decarboxylase genes (Pc13g9300 and Pc18g01490). cDNAs of both genes were cloned and expressed in the 2-oxo-acid-decarboxylase-free Saccharomyces cerevisiae strain CEN.PK711-7C (pdc1 pdc5 pdc6Δ aro10Δ thi3Δ). The introduction of Pc13g09300 restored the growth of this S. cerevisiae mutant on glucose and phenylalanine, thereby demonstrating that Pc13g09300 encodes a dual-substrate pyruvate and phenylpyruvate decarboxylase, which plays a key role in an Ehrlich-type pathway for the production of phenylacetate in P. chrysogenum. These results provide a basis for the metabolic engineering of P. chrysogenum for the production of the penicillin G side chain precursor phenylacetate. PMID:22158714
The lipoxygenase pathway in tulip (Tulipa gesneriana): detection of the ketol route.

PubMed

Grechkin, A N; Mukhtarova, L S; Hamberg, M

2000-12-01

The in vitro metabolism of [1-(14)C]linoleate, [1-(14)C]linolenate and their 9(S)-hydroperoxides was studied in cell-free preparations from tulip (Tulipa gesneriana) bulbs, leaves and flowers. Linoleate and its 9-hydroperoxide were converted by bulb and leaf preparations into three ketols: (12Z)-9-hydroxy-10-oxo-12-octadecadienoic acid (alpha-ketol), (11E)-10-oxo-13-hydroxy-11-octadecadienoic acid (gamma-ketol) and a novel compound, (12Z)-10-oxo-11-hydroxy-12-octadecadienoic acid (10,11-ketol), in the approximate molar proportions of 10:3:1. The corresponding 15, 16-dehydro alpha- and gamma-ketols were the main metabolites of [1-(14)C]linolenate and its 9-hydroperoxide. Thus bulbs and leaves possessed 9-lipoxygenase and allene oxide synthase activities. Incubations with flower preparations gave alpha-ketol hydro(pero)xides as predominant metabolites. Bulb and leaf preparations possessed a novel enzyme activity, gamma-ketol reductase, which reduces gamma-ketol to 10-oxo-13-hydroxyoctadecanoic acid (dihydro-gamma-ketol) in the presence of NADH. Exogenous linolenate 13(S)-hydroperoxide was converted mostly into chiral (9S,13S)-12-oxo-10-phytodienoate (99.5% optical purity) by bulb preparations, while [1-(14)C]linolenate was a precursor for ketols only. Thus tulip bulbs possess abundant allene oxide cyclase activity, the substrate for which is linolenate 13(S)-hydroperoxide, even though 13(S)-lipoxygenase products were not detectable in the bulbs. The majority of the cyclase activity was found in the microsomes (10(5) g pellet). Cyclase activity was not found in the other tissues examined, but only in the bulbs. The ketol route of the lipoxygenase pathway, mediated by 9-lipoxygenase and allene oxide synthase activities, has not been detected previously in the vegetative organs of any plant species.
The lipoxygenase pathway in tulip (Tulipa gesneriana): detection of the ketol route.

PubMed Central

Grechkin, A N; Mukhtarova, L S; Hamberg, M

2000-01-01

The in vitro metabolism of [1-(14)C]linoleate, [1-(14)C]linolenate and their 9(S)-hydroperoxides was studied in cell-free preparations from tulip (Tulipa gesneriana) bulbs, leaves and flowers. Linoleate and its 9-hydroperoxide were converted by bulb and leaf preparations into three ketols: (12Z)-9-hydroxy-10-oxo-12-octadecadienoic acid (alpha-ketol), (11E)-10-oxo-13-hydroxy-11-octadecadienoic acid (gamma-ketol) and a novel compound, (12Z)-10-oxo-11-hydroxy-12-octadecadienoic acid (10,11-ketol), in the approximate molar proportions of 10:3:1. The corresponding 15, 16-dehydro alpha- and gamma-ketols were the main metabolites of [1-(14)C]linolenate and its 9-hydroperoxide. Thus bulbs and leaves possessed 9-lipoxygenase and allene oxide synthase activities. Incubations with flower preparations gave alpha-ketol hydro(pero)xides as predominant metabolites. Bulb and leaf preparations possessed a novel enzyme activity, gamma-ketol reductase, which reduces gamma-ketol to 10-oxo-13-hydroxyoctadecanoic acid (dihydro-gamma-ketol) in the presence of NADH. Exogenous linolenate 13(S)-hydroperoxide was converted mostly into chiral (9S,13S)-12-oxo-10-phytodienoate (99.5% optical purity) by bulb preparations, while [1-(14)C]linolenate was a precursor for ketols only. Thus tulip bulbs possess abundant allene oxide cyclase activity, the substrate for which is linolenate 13(S)-hydroperoxide, even though 13(S)-lipoxygenase products were not detectable in the bulbs. The majority of the cyclase activity was found in the microsomes (10(5) g pellet). Cyclase activity was not found in the other tissues examined, but only in the bulbs. The ketol route of the lipoxygenase pathway, mediated by 9-lipoxygenase and allene oxide synthase activities, has not been detected previously in the vegetative organs of any plant species. PMID:11085944
Decarboxylase inhibition and blood pressure reduction by alpha-methyl-3,4-dihydroxy-DL-phenylalanine.

PubMed

OATES, J A; GILLESPIE, L; UDENFRIEND, S; SJOERDSMA, A

1960-06-24

alpha-Methyl-3,4-dihydroxy-DLphenylalanine has been found to be an effective inhibitor of aromatic amino acid decarboxylation in man. This was shown by decreased formation of serotonin, tryptamine, and tyramine from the precursor amino acids. Reduction of amine biosynthesis is associated with lowering of blood pressure in hypertensive patients and a transient sedative effect.
[Studies on chemical constituents of Pinus armandii].

PubMed

Yang, Xin; Ding, Yi; Sun, Zhi-hao; Zhang, Dong-ming

2005-05-01

To study chemical constituents from pine cone of Pinus armandii Franch. The constituents were isolated by chromatographic method and the structures were identified on the basis of spectral analysis. Four compounds were identified as 7-oxo-12alpha, 13beta-dihydroxyabiet-8(14)-en18-oic acid (I), 7-oxo-13beta-hydroxyabiet-8 (14)-en-18-oic acid (II), 8 (14)-podocarpen-13-on-18-oic acid (III) and lambertianic acid (IV). Compound I is a new diterpenoid and compounds II, III were isolated from this plant for the first time.
Crystal Structures of Apo and Liganded 4-Oxalocrotonate Decarboxylase Uncover a Structural Basis for the Metal-Assisted Decarboxylation of a Vinylogous β-Keto Acid.

PubMed

Guimarães, Samuel L; Coitinho, Juliana B; Costa, Débora M A; Araújo, Simara S; Whitman, Christian P; Nagem, Ronaldo A P

2016-05-10

The enzymes in the catechol meta-fission pathway have been studied for more than 50 years in several species of bacteria capable of degrading a number of aromatic compounds. In a related pathway, naphthalene, a toxic polycyclic aromatic hydrocarbon, is fully degraded to intermediates of the tricarboxylic acid cycle by the soil bacteria Pseudomonas putida G7. In this organism, the 83 kb NAH7 plasmid carries several genes involved in this biotransformation process. One enzyme in this route, NahK, a 4-oxalocrotonate decarboxylase (4-OD), converts 2-oxo-3-hexenedioate to 2-hydroxy-2,4-pentadienoate using Mg(2+) as a cofactor. Efforts to study how 4-OD catalyzes this decarboxylation have been hampered because 4-OD is present in a complex with vinylpyruvate hydratase (VPH), which is the next enzyme in the same pathway. For the first time, a monomeric, stable, and active 4-OD has been expressed and purified in the absence of VPH. Crystal structures for NahK in the apo form and bonded with five substrate analogues were obtained using two distinct crystallization conditions. Analysis of the crystal structures implicates a lid domain in substrate binding and suggests roles for specific residues in a proposed reaction mechanism. In addition, we assign a possible function for the NahK N-terminal domain, which differs from most of the other members of the fumarylacetoacetate hydrolase superfamily. Although the structural basis for metal-dependent β-keto acid decarboxylases has been reported, this is the first structural report for that of a vinylogous β-keto acid decarboxylase and the first crystal structure of a 4-OD.
Evolution of Substrate Specificity within a Diverse Family of [beta/alpha]-Barrel-fold Basic Amino Acid Decarboxylases X-ray Structure Determination of Enzymes with Specificity for L-Arginine and Carboxynorspermidine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Xiaoyi; Lee, Jeongmi; Michael, Anthony J.

2010-08-26

Pyridoxal 5{prime}-phosphate (PLP)-dependent basic amino acid decarboxylases from the {beta}/{alpha}-barrel-fold class (group IV) exist in most organisms and catalyze the decarboxylation of diverse substrates, essential for polyamine and lysine biosynthesis. Herein we describe the first x-ray structure determination of bacterial biosynthetic arginine decarboxylase (ADC) and carboxynorspermidine decarboxylase (CANSDC) to 2.3- and 2.0-{angstrom} resolution, solved as product complexes with agmatine and norspermidine. Despite low overall sequence identity, the monomeric and dimeric structures are similar to other enzymes in the family, with the active sites formed between the {beta}/{alpha}-barrel domain of one subunit and the {beta}-barrel of the other. ADC contains bothmore » a unique interdomain insertion (4-helical bundle) and a C-terminal extension (3-helical bundle) and it packs as a tetramer in the asymmetric unit with the insertions forming part of the dimer and tetramer interfaces. Analytical ultracentrifugation studies confirmed that the ADC solution structure is a tetramer. Specificity for different basic amino acids appears to arise primarily from changes in the position of, and amino acid replacements in, a helix in the {beta}-barrel domain we refer to as the 'specificity helix.' Additionally, in CANSDC a key acidic residue that interacts with the distal amino group of other substrates is replaced by Leu{sup 314}, which interacts with the aliphatic portion of norspermidine. Neither product, agmatine in ADC nor norspermidine in CANSDC, form a Schiff base to pyridoxal 5{prime}-phosphate, suggesting that the product complexes may promote product release by slowing the back reaction. These studies provide insight into the structural basis for the evolution of novel function within a common structural-fold.« less
21 CFR 173.115 - Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant Bacillus...

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Alpha-acetolactate decarboxylase (Î±-ALDC) enzyme... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.115 Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant Bacillus subtilis. The food additive alpha...
40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2012 CFR

2012-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...
40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2010 CFR

2010-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...
40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2014 CFR

2014-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...
40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2013 CFR

2013-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...
40 CFR 721.10160 - Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen...

Code of Federal Regulations, 2011 CFR

2011-07-01

....-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl]oxy]-. 721.10160 Section 721.10160... Poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1-oxo-13-docosen-1-yl... substance identified as poly(oxy-1,2-ethanediyl), .alpha.-[(13Z)-1-oxo-13-docosen-1-yl]-.omega.-[[(13Z)-1...

21 CFR 173.115 - Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant Bacillus...

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Alpha-acetolactate decarboxylase (Î±-ALDC) enzyme...) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.115 Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant...
21 CFR 173.115 - Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant Bacillus...

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Alpha-acetolactate decarboxylase (Î±-ALDC) enzyme...) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.115 Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant...
21 CFR 173.115 - Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant Bacillus...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Alpha-acetolactate decarboxylase (Î±-ALDC) enzyme...) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.115 Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant...
21 CFR 173.115 - Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant Bacillus...

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Alpha-acetolactate decarboxylase (Î±-ALDC) enzyme...) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.115 Alpha-acetolactate decarboxylase (α-ALDC) enzyme preparation derived from a recombinant...
An efficient synthesis of the constrained peptidomimetic 2-oxo-3-(N-9-fluorenyloxycarbonylamino)-1-azabicyclo[4.3.0]nonane-9-carboxylic acid from pyroglutamic acid.

PubMed

Mandal, Pijus Kumar; Kaluarachchi, Kumar K; Ogrin, Douglas; Bott, Simon G; McMurray, John S

2005-11-25

[reaction: see text] Azabicyclo[X.Y.0]alkane amino acids are rigid dipeptide mimetics that are useful tools for structure-activity studies in peptide-based drug discovery. Herein, we report an efficient synthesis of three diastereomers of 9-tert-butoxycarbonyl-2-oxo-3-(N-tert-butoxycarbonylamino)-1-azabicyclo[4.3.0]nonane (3S,6S,9S, 3S,6R,9R, and 3S,6R,9S). Methyl N-Boc-pyroglutamate is cleaved with vinylmagnesium bromide to produce an acyclic gamma-vinyl ketone. Michael addition of N-diphenylmethyleneglycine tert-butyl ester produces the N-Boc-delta-oxo-alpha,omega-diaminoazelate intermediate, which, on hydrogenloysis, gives the fused ring system. Acidolytic deprotection followed by Fmoc-protection provided building blocks suitable for solid-phase synthesis.
Discovery of an imidazopyridine-containing 1,4-benzodiazepine nonpeptide vitronectin receptor (alpha v beta 3) antagonist with efficacy in a restenosis model.

PubMed

Keenan, R M; Lago, M A; Miller, W H; Ali, F E; Cousins, R D; Hall, L B; Hwang, S M; Jakas, D R; Kwon, C; Louden, C; Nguyen, T T; Ohlstein, E H; Rieman, D J; Ross, S T; Samanen, J M; Smith, B R; Stadel, J; Takata, D T; Vickery, L; Yuan, C C; Yue, T L

1998-11-17

In the 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (alpha v beta 3) antagonists, a compound containing an imidazopyridine arginine mimetic was discovered which had sufficient potency and i.v. pharmacokinetics for demonstration of efficacy in a rat restenosis model.
Nicotinic acetylcholine receptor alpha5 subunits modulate oxotremorine-induced salivation and tremor.

PubMed

Wang, Ningshan; Orr-Urtreger, Avi; Chapman, Joab; Rabinowitz, Ruth; Korczyn, Amos D

2004-07-15

Neuronal nicotinic acetylcholine receptors (nAChRs) are composed of 12 subunits (alpha2-alpha10 and beta2-beta4). alpha5 Subunits, expressed throughout the central nervous system (CNS) and the autonomic nervous system (ANS), possess unique pharmacological properties. The effects of oxotremorine (OXO) on autonomic functions and tremor were examined in mice lacking alpha5 nAChR subunits (alpha5-/-) and compared with those in wild-type (WT) control mice. The alpha5-/- mice showed significantly increased salivation and tremor responses to OXO. The hypothermia, bradycardia and defecation induced by OXO were of similar magnitudes in the two mouse strains. The enhanced OXO effects in alpha5-/- mice indicate inhibitory effects of alpha5 subunits in autonomic ganglia, and support the participation of these subunits in cholinergic transmission in autonomic ganglia.
40 CFR 721.9663 - Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., alphaâ²-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis (C11-15 and C11-15-isoalkyl) ethers. 721... Substances § 721.9663 Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega...′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis(C11-15 and C11-15-isoalkyl) ethers (PMN P-97-497...
40 CFR 721.9663 - Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., alphaâ²-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis (C11-15 and C11-15-isoalkyl) ethers. 721... Substances § 721.9663 Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega...′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis(C11-15 and C11-15-isoalkyl) ethers (PMN P-97-497...
40 CFR 721.9663 - Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., alphaâ²-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis (C11-15 and C11-15-isoalkyl) ethers. 721... Substances § 721.9663 Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega...′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis(C11-15 and C11-15-isoalkyl) ethers (PMN P-97-497...
40 CFR 721.9663 - Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., alphaâ²-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis (C11-15 and C11-15-isoalkyl) ethers. 721... Substances § 721.9663 Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega...′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis(C11-15 and C11-15-isoalkyl) ethers (PMN P-97-497...
40 CFR 721.10336 - Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-oxo-2-propen-1-yl)-.omega.-([1,1â²-biphenyl]-2-yloxy)-. 721.10336 Section 721.10336 Protection of...-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-. (a) Chemical substance and...), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)- (PMN P-04-1; CAS No. 72009-86-0) is...
40 CFR 721.10336 - Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-oxo-2-propen-1-yl)-.omega.-([1,1â²-biphenyl]-2-yloxy)-. 721.10336 Section 721.10336 Protection of...-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-. (a) Chemical substance and...), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)- (PMN P-04-1; CAS No. 72009-86-0) is...
40 CFR 721.10336 - Poly(oxy-1,2-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-oxo-2-propen-1-yl)-.omega.-([1,1â²-biphenyl]-2-yloxy)-. 721.10336 Section 721.10336 Protection of...-ethanediyl), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)-. (a) Chemical substance and...), .alpha.-(1-oxo-2-propen-1-yl)-.omega.-([1,1′-biphenyl]-2-yloxy)- (PMN P-04-1; CAS No. 72009-86-0) is...
40 CFR 721.9663 - Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., alphaâ²-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis (C11-15 and C11-15-isoalkyl) ethers. 721... Substances § 721.9663 Poly(oxy-1,2-ethanediyl), alpha, alpha′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega...′-[thiobis (1-oxo-3,1-propanediyl)]bis [omega-hydroxy-,bis(C11-15 and C11-15-isoalkyl) ethers (PMN P-97-497...
Swit_4259, an acetoacetate decarboxylase-like enzyme from Sphingomonas wittichii RW1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mydy, Lisa S.; Mashhadi, Zahra; Knight, T. William

The Gram-negative bacteriumSphingomonas wittichiiRW1 is notable for its ability to metabolize a variety of aromatic hydrocarbons. Not surprisingly, theS. wittichiigenome contains a number of putative aromatic hydrocarbon-degrading gene clusters. One of these includes an enzyme of unknown function, Swit_4259, which belongs to the acetoacetate decarboxylase-like superfamily (ADCSF). Here, it is reported that Swit_4259 is a small (28.8 kDa) tetrameric ADCSF enzyme that, unlike the prototypical members of the superfamily, does not have acetoacetate decarboxylase activity. Structural characterization shows that the tertiary structure of Swit_4259 is nearly identical to that of the true decarboxylases, but there are important differences in themore » fine structure of the Swit_4259 active site that lead to a divergence in function. In addition, it is shown that while it is a poor substrate, Swit_4259 can catalyze the hydration of 2-oxo-hex-3-enedioate to yield 2-oxo-4-hydroxyhexanedioate. It is also demonstrated that Swit_4259 has pyruvate aldolase-dehydratase activity, a feature that is common to all of the family V ADCSF enzymes studied to date. The enzymatic activity, together with the genomic context, suggests that Swit_4259 may be a hydratase with a role in the metabolism of an as-yet-unknown hydrocarbon. These data have implications for engineering bioremediation pathways to degrade specific pollutants, as well as structure–function relationships within the ADCSF in general.« less
Diastereoselective addition of 2H-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines.

PubMed

Pirat, Jean-Luc; Monbrun, Jérôme; Virieux, David; Volle, Jean-Noël; Tillard, Monique; Cristau, Henri-Jean

2005-09-02

[reaction: see text] Diastereoselective additions of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines are described. alpha,alpha'-Diaminophosphinic and alpha-amino-alpha'-hydroxyphosphinic derivatives were obtained with de's ranging from 24 to 90%.
[Rapid identification of two new isomers in bear bile powder by LC-Q-TOF-MS combined with PCC oxidation].

PubMed

Jian, Long-Hai; Hu, Chun; Yu, Hong; Wang, Ke; Ji, Shen

2013-07-01

A rapid method of Liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) combined with pyridinium chlorochromate (PCC) oxidation has been developed to determine chemical structures of two novel isomers in bear bile powder. Derivatives of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) were semi-synthesized by PCC oxidation, then were analyzed by LC-Q-TOF-MS. Separation was carried out on a reverse column with the mobile phase of acetonitrile-0.1% formic acid (45:55). The data of Q-TOF-MS was acquired by MS, MS/MS, positive and negative modes. Since UDCA and CDCA were stereochemical isomeric at an alcohol position, two oxidation products were same and have been confirmed by LC-Q-TOF-MS. Other two products were also determined based on the PCC oxidation theory. Samples of bear bile powder were dissolved by methanol and measured by LC-Q-TOF-MS. Two unknown peaks were found and identified by matching their retention times and accurate mass spectra ions with PCC oxidation productS. Finally, the structures of two new bile acids in bear bile powder were confirmed as 3alpha-hydroxy-7-oxo-5beta-cholanic acid, 7alpha-hydroxy-3-oxo-5beta-cholanic acid, respectively.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikolau, Basil J; Wurtele, Eve S; Oliver, David J

The present invention provides nucleic acid and amino acid sequences of acetyl CoA synthetase (ACS), plastidic pyruvate dehydrogenase (pPDH), ATP citrate lyase (ACL), Arabidopsis pyruvate decarboxylase (PDC), and Arabidopsis aldehyde dehydrogenase (ALDH), specifically ALDH-2 and ALDH-4. The present invention also provides a recombinant vector comprising a nucleic acid sequence encoding one of the aforementioned enzymes, an antisense sequence thereto or a ribozyme therefor, a cell transformed with such a vector, antibodies to the enzymes, a plant cell, a plant tissue, a plant organ or a plant in which the level of an enzyme has been altered, and a method ofmore » producing such a plant cell, plant tissue, plant organ or plant. Desirably, alteration of the level of enzyme results in an alteration of the level of acetyl CoA in the plant cell, plant tissue, plant organ or plant. In addition, the present invention provides a recombinant vector comprising an antisense sequence of a nucleic acid sequence encoding pyruvate decarboxylase (PDC), the E1.alpha. subunit of pPDH, the E1.beta. subunit of pPDH, the E2 subunit of pPDH, mitochondrial pyruvate dehydrogenase (mtPDH) or aldehyde dehydrogenase (ALDH) or a ribozyme that can cleave an RNA molecule encoding PDC, E1.alpha. pPDH, E1.beta. pPDH, E2 pPDH, mtPDH or ALDH.« less
40 CFR 721.9582 - Certain perfluoroalkyl sulfonates.

Code of Federal Regulations, 2014 CFR

2014-07-01

...[(heptadecafluorooctyl)sulfonyl]amino]ethyl]-.omega.-hydroxy- 29457-72-5 1-Octanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7...-octanethiol and .alpha.-(1-oxo-2-propenyl)-.omega.-methoxypoly(oxy-1,2-ethanediyl) 68891-96-3 Chromium...[(heptadecafluorooctyl)sulfonyl]amino]ethyl]-.omega.-methoxy- 70225-14-8 1-Octanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7...

Materials and methods for the alteration of enzyme and acetyl CoA levels in plants

DOEpatents

Nikolau, Basil J.; Wurtele, Eve S.; Oliver, David J.; Behal, Robert; Schnable, Patrick S.; Ke, Jinshan; Johnson, Jerry L.; Allred, Carolyn C.; Fatland, Beth; Lutziger, Isabelle; Wen, Tsui-Jung

2005-09-13

The present invention provides nucleic acid and amino acid sequences of acetyl CoA synthetase (ACS), plastidic pyruvate dehydrogenase (pPDH), ATP citrate lyase (ACL), Arabidopsis pyruvate decarboxylase (PDC), and Arabidopsis aldehyde dehydrogenase (ALDH), specifically ALDH-2 and ALDH-4. The present invention also provides a recombinant vector comprising a nucleic acid sequence encoding one of the aforementioned enzymes, an antisense sequence thereto or a ribozyme therefor, a cell transformed with such a vector, antibodies to the enzymes, a plant cell, a plant tissue, a plant organ or a plant in which the level of an enzyme has been altered, and a method of producing such a plant cell, plant tissue, plant organ or plant. Desirably, alteration of the level of enzyme results in an alteration of the level of acetyl CoA in the plant cell, plant tissue, plant organ or plant. In addition, the present invention provides a recombinant vector comprising an antisense sequence of a nucleic acid sequence encoding pyruvate decarboxylase (PDC), the E1.alpha. subunit of pPDH, the E1.beta. subunit of pPDH, the E2 subunit of pPDH, mitochondrial pyruvate dehydrogenase (mtPDH) or aldehyde dehydrogenase (ALDH) or a ribozyme that can cleave an RNA molecule encoding PDC, E1.alpha. pPDH, E1.beta. pPDH, E2 pPDH, mtPDH or ALDH.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikolau, Basil J.; Wurtele, Eve S.; Oliver, David J.

The present invention provides nucleic acid and amino acid sequences of acetyl CoA synthetase (ACS), plastidic pyruvate dehydrogenase (pPDH), ATP citrate lyase (ACL), Arabidopsis pyruvate decarboxylase (PDC), and Arabidopsis aldehyde dehydrogenase (ALDH), specifically ALDH-2 and ALDH-4. The present invention also provides a recombinant vector comprising a nucleic acid sequence encoding one of the aforementioned enzymes, an antisense sequence thereto or a ribozyme therefor, a cell transformed with such a vector, antibodies to the enzymes, a plant cell, a plant tissue, a plant organ or a plant in which the level of an enzyme has been altered, and a method ofmore » producing such a plant cell, plant tissue, plant organ or plant. Desirably, alteration of the level of enzyme results in an alteration of the level of acetyl CoA in the plant cell, plant tissue, plant organ or plant. In addition, the present invention provides a recombinant vector comprising an antisense sequence of a nucleic acid sequence encoding pyruvate decarboxylase (PDC), the E1.sub..alpha. subunit of pPDH, the E1.sub..beta. subunit of pPDH, the E2 subunit of pPDH, mitochondrial pyurvate dehydrogenase (mtPDH) or aldehyde dehydrogenase (ALDH) or a ribozyme that can cleave an RNA molecule encoding PDC, E1.sub..alpha. pPDH, E1.sub..beta. pPDH, E2 pPDH, mtPDH or ALDH.« less
Evidence for arginine as the endogenous precursor of necines in heliotropium.

PubMed

Birecka, H; Birecki, M; Frohlich, M W

1987-05-01

In pyrrolizidine alkaloid-bearing Heliotropium angiospermum and H. indicum shoots exposed, in the light, to (14)C-labeled CO(2) for 44 hours, the incorporation of (14)C into 1,2-epoxy-1-hydroxymethylpyrrolizidine and retronecine amounted to 0.23 and 0.15%, respectively, of the total carbon assimilated. Treatment of the shoots with alpha-dl-difluoromethylornithine, the specific ornithine decarboxylase inhibitor, at 1 to 2 millimolar had no effect on (14)C incorporation into the necines. In contrast, alpha-dl-difluoromethylarginine, the specific arginine decarboxylase inhibitor, prevented the incorporation of (14)C into the necines of both species; the inhibitor did not affect the absolute incorporation of (14)C from exogenous [1,4-(14)C] putrescine in either species. Thus, arginine is the only apparent endogenous precursor of the putrescine channeled into pyrrolizidines, at least in these two Heliotropium species that exhibited a relatively much higher in vitro activity of arginine decarboxylase than of ornithine decarboxylase. However, within 28 hours after administration, not only exogenous l-[5-(14)C]arginine, but also exogenous l-[5-(14)C]ornithine exhibited significant incorporation of their label into the necines, incorporation that could be partially prevented by both inhibitors. Neither inhibitor affected the rates of (14)C-labeled CO(2) assimilation, transformation of labeled assimilates into ethanol-insoluble compounds, or the very high degree of conversion of the introduced amino acids into other compounds. Methodology related to alkaloid biosynthetic studies is discussed.
Dimerization of A-[alpha]-[SiNb3W9O40]7- by pH-controlled formation of individual Nb−µ-O−Nb linkages

Treesearch

Gyu-Shik Kim; Huadong Zeng; Wade A. Neiwert; Jennifer J. Cowan; Donald VanDerveer; Craig L. Hill; Ira A. Weinstock

2003-01-01

The reversible, stepwise formation of individual Nb−Âµ-O−Nb linkages during acid condensation of 2 equiv of A-[alpha]-[SiNb3W9O40]7- (1) to the tri-Âµ-oxo-bridged structure A-[alpha]-[Si2Nb6W18O77]8- (4) is demonstrated by a combination of X-ray crystallography and variable-pD solution 183W and 29Si NMR spectroscopy. Addition of DCl to a pD 8.4...
Development of a novel ultrasensitive enzyme immunoassay for human glutamic acid decarboxylase 65 antibody.

PubMed

Numata, Satoshi; Katakami, Hideki; Inoue, Shinobu; Sawada, Hirotake; Hashida, Seiichi

2016-07-01

We developed a novel, ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for determination of glutamic acid decarboxylase autoantibody concentrations in serum samples from patients with type 2 diabetes. We developed an immune complex transfer enzyme immunoassay for glutamic acid decarboxylase autoantibody and measured glutamic acid decarboxylase autoantibody from 22 patients with type 1 diabetes, 29 patients with type 2 diabetes, and 32 healthy controls. A conventional ELISA kit identified 10 patients with type 1 diabetes and one patient with type 2 diabetes as glutamic acid decarboxylase autoantibody positive, whereas 15 patients with type 1 diabetes and six patients with type 2 diabetes were identified as glutamic acid decarboxylase autoantibody positive using immune complex transfer enzyme immunoassay. Immune complex transfer enzyme immunoassay is a highly sensitive and specific assay for glutamic acid decarboxylase autoantibody and might be clinically useful for diabetic onset prediction and early diagnosis. © The Author(s) 2016.
Steroid catechol degradation: disecoandrostane intermediates accumulated by Pseudomonas transposon mutant strains.

PubMed

Leppik, R A

1989-07-01

Eleven transposon mutant strains affected in bile acid catabolism were each found to form yellow, muconic-like intermediates from bile acids. To characterize these unstable intermediates, media from the growth of one of these mutants with deoxycholic acid was treated with ammonia, then the crude product was methylated with diazomethane. Four compounds were subsequently isolated; spectral evidence suggested that they were methyl 12 alpha-hydroxy-3-oxo-23,24-dinorchola-1,4-dien-22-oate, methyl 4-aza-12 beta-hydroxy-9(10)-secoandrosta-1,3,5-triene-9,17-dione-3-carboxyl ate, 4-aza-9 alpha, 12 beta-dihydroxy-9(10)-secoandrosta-1,3,5-trien-17-one-3- methyl carboxylate and 4 alpha-[3'-propionic acid]-5-amino-7 beta-hydroxy-7 alpha beta-methyl- 3a alpha, 4,7,7a-tetrahydro-1-indanone-delta-lactam. It is proposed that the mutants are blocked in the utilization of such muconic-like compounds as the 3,12 beta-dihydroxy-5,9,17-trioxo-4(5),9(10)- disecoandrostal (10),2-dien-4-oic acid formed from deoxycholic acid. A further mutant was examined, which converted deoxycholic acid to 12 alpha-hydroxyandrosta-1,4-dien-3,17-dione, but accumulated yellow products from steroids which lacked a 12 alpha-hydroxy function, such as chenodeoxycholic acid. The products from the latter acid were treated as above; spectral evidence suggested that the two compounds isolated were methyl 4-aza-7-hydroxy-9(10)-secoandrosta-1,3,5- triene-9,17-dione-3-carboxylate and 4 alpha-[1'alpha-hydroxy-3'-propionic acid]-5-amino-7a beta-methyl-3a alpha,4,7,7a-tetrahydro-1-indanone-delta-lactam.
Trypanocidal constituents in plants 6. 1) Minor withanolides from the aerial parts of Physalis angulata.

PubMed

Abe, Fumiko; Nagafuji, Shinya; Okawa, Masafumi; Kinjo, Junei

2006-08-01

Further study of the methanol extract of the aerial parts of Physalis angulata (Solanaceae) resulted in the isolation of new withanolides, designated physagulins L, M and N, together with known withanolide, physagulin D and flavonol glycoside, quercetin 3-O-rhamnosyl-(1-->6)-galactoside. The chemical structures of these new withanolides were elucidated by detailed spectroscopic analyses to be (20R,22R)-15alpha-acetoxy-5alpha,6beta,14beta,17beta,27-pentahydroxy-1-oxo-witha-2, 24-dienolide, (20S,22S)-15alpha-acetoxy-5alpha,6beta,14alpha,23beta-tetrahydroxy-1-oxo-witha-2,16,24-trienolide and (20S,22R)-15alpha-acetoxy-5beta,6beta-epoxy-14alpha-hydoxy-3beta-methoxy-1-oxo-witha-16,24-dienolide, respectively. All these compounds showed weak trypanocidal activity against trypomastigotes, an infectious form of Trypanosoma cruzi, the etiologic agent for Chagas' disease. Withanolides obtained in the previous paper showed considerable trypanocidal activity, suggesting the structure-activity relationships.
Metabolism of valine and 3-methyl-2-oxobutanoate by the isolated perfused rat kidney.

PubMed Central

Miller, R H; Harper, A E

1984-01-01

Metabolism of branched-chain amino and 2-oxo acids was studied in the isolated perfused kidney. Significant amounts of 2-oxo acids were released by perfused kidney with all concentrations of amino acids tested (0.1-1.0 mM each), despite the high activity of branched-chain 2-oxo acid dehydrogenase in kidney. As perfusate valine concentration was increased from 0.2 to 1.0 mM, [1-14C]valine transamination (2-oxo acid oxidized + released) increased roughly linearly; [1-14C]valine oxidation, however, increased exponentially. Increasing perfusate concentration of 3-methyl-2-oxo[1-14C]butanoate from 0 to 1.0 mM resulted in a linear increase in the rate of its oxidation and a rise in perfusate valine concentration; at the same time significant decreases occurred in perfusate isoleucine and leucine concentrations, with corresponding increases in rates of release of their respective 2-oxo acids. Comparison of rates of oxidation of [1-14C]valine and 3-methyl-2-oxo[1-14C]butanoate suggests that 2-oxo acid arising from [1-14C]valine transamination has freer access to the 2-oxo acid dehydrogenase than has the 2-oxo acid from the perfusate. The observations indicate that, when branched-chain amino and 2-oxo acids are present in perfusate at near-physiological concentrations, rates of transamination of the amino and 2-oxo acids by isolated perfused kidney are greater than rates of oxidation. PMID:6508752
Conceptual biotransformation of 4-oxo-all-trans-retinoic acid, 4-oxo-13-cis-retinoic acid and all-trans-retinoyl-beta-glucuronide in rat whole embryo culture.

PubMed

Creech Kraft, J; Juchau, M R

1992-05-28

In cultured rat conceptuses, intraamniotic microinjections of 2500 ng/mL of 4-oxo-13-cis-retinoic acid, 600 ng/mL 4-oxo-all-trans-retinoic acid or 4000 ng/mL all-trans-retinoyl-beta-glucuronide, produce qualitatively and quantitatively similar patterns of dysmorphogenesis as those reported after the intraamniotic microinjection of 250 ng/mL all-trans-retinoic acid [Lee et al., Teratology 44: 313-323, 1991; Creech Kraft et al., Teratology 45: 259-270, 1992]. In the present study, we utilized HPLC techniques to analyze retinoid levels in cultured rat conceptuses, 1.5 hr after intraamniotic microinjections of 4-oxo-13-cis-retinoic acid (2500 ng/mL), 4-oxo-all-trans-retinoic acid (600 ng/mL) or all-trans-retinoyl-beta-glucuronide (4000 ng/mL). Our findings show that, after the microinjections of 4-oxo-all-trans-retinoic acid or 4-oxo-13-cis-retinoic acid (at these selected concentrations), 4-oxo-all-trans-retinoic acid was predominant in the embryos proper at concentrations of about 200 nM. This was roughly equivalent to the levels of all-trans-retinoic acid assayed after microinjections of all-trans-retinoyl-beta-glucuronide (4000 ng/mL). We conclude from these studies that both 4-oxo-all-trans-retinoic acid and all-trans-retinoic acid behave as ultimate or proximate dysmorphogens.
Kinetic Re-Evaluation of Fuel Neutralization by AKGA

NASA Technical Reports Server (NTRS)

Oropeza Cristina; Kosiba, Mike; Davis, Chuck

2010-01-01

Baseline characterization testing previously identified alpha-ketoglutaric acid (AKGA) cis a potential alternative to the current standard hydrazine (HZ) family fuel neutralization techniques in use at Kennedy Space Center (KSC). Thus far, the reagent shows promise for use in hardware decontamination operations and as a drop-in replacement for the scrubber liquor currently used in KSC four tower vapor scrubbers. Implementation of AKGA could improve process safety and reduce or eliminate generation of hydrazine-Iaden waste streams. This paper focuses on evaluation of the kinetics of these decontamination reactions in solution. Pseudo first order reaction rate constants with respect to the pyridazine products (6-oxo-4,5-dihydro-1H-pyridazine-3-carboxylic acid, (PCA) and 1-methyl-6-oxo-4,5-dihydro-pyridazine-3-carboxylic acid (mPCA)) in the presence of excess AKGA were determined by monitoring product formation using a ultra-violet visible absorption spectroscopy method. The results are presented here in comparison to previous data obtained by monitoring reactant depletion by gas chromatography with nitrogen phosphorus detector (GC-NPD).
Glutamic acid decarboxylase isoform distribution in transgenic mouse septum: an anti-GFP immunofluorescence study.

PubMed

Verimli, Ural; Sehirli, Umit S

2016-09-01

The septum is a basal forebrain region located between the lateral ventricles in rodents. It consists of lateral and medial divisions. Medial septal projections regulate hippocampal theta rhythm whereas lateral septal projections are involved in processes such as affective functions, memory formation, and behavioral responses. Gamma-aminobutyric acidergic neurons of the septal region possess the 65 and 67 isoforms of the enzyme glutamic acid decarboxylase. Although data on the glutamic acid decarboxylase isoform distribution in the septal region generally appears to indicate glutamic acid decarboxylase 67 dominance, different studies have given inconsistent results in this regard. The aim of this study was therefore to obtain information on the distributions of both of these glutamic acid decarboxylase isoforms in the septal region in transgenic mice. Two animal groups of glutamic acid decarboxylase-green fluorescent protein knock-in transgenic mice were utilized in the experiment. Brain sections from the region were taken for anti-green fluorescent protein immunohistochemistry in order to obtain estimated quantitative data on the number of gamma-aminobutyric acidergic neurons. Following the immunohistochemical procedures, the mean numbers of labeled cells in the lateral and medial septal nuclei were obtained for the two isoform groups. Statistical analysis yielded significant results which indicated that the 65 isoform of glutamic acid decarboxylase predominates in both lateral and medial septal nuclei (unpaired two-tailed t-test p < 0.0001 for LS, p < 0.01 for MS). This study is the first to reveal the dominance of glutamic acid decarboxylase isoform 65 in the septal region in glutamic acid decarboxylase-green fluorescent protein transgenic mice.
40 CFR 721.430 - Oxo-substituted amino-al-kanoic acid derivative.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Oxo-substituted amino-al-kanoic acid... Specific Chemical Substances § 721.430 Oxo-substituted amino-al-kanoic acid derivative. (a) Chemical... as oxo-substituted amino al-kan-oic acid derivative (PMN No. P-92-692) is subject to reporting under...
40 CFR 721.430 - Oxo-substituted amino-al-kanoic acid derivative.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Oxo-substituted amino-al-kanoic acid... Specific Chemical Substances § 721.430 Oxo-substituted amino-al-kanoic acid derivative. (a) Chemical... as oxo-substituted amino al-kan-oic acid derivative (PMN No. P-92-692) is subject to reporting under...
40 CFR 721.430 - Oxo-substituted amino-al-kanoic acid derivative.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Oxo-substituted amino-al-kanoic acid... Specific Chemical Substances § 721.430 Oxo-substituted amino-al-kanoic acid derivative. (a) Chemical... as oxo-substituted amino al-kan-oic acid derivative (PMN No. P-92-692) is subject to reporting under...
40 CFR 721.430 - Oxo-substituted amino-al-kanoic acid derivative.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Oxo-substituted amino-al-kanoic acid... Specific Chemical Substances § 721.430 Oxo-substituted amino-al-kanoic acid derivative. (a) Chemical... as oxo-substituted amino al-kan-oic acid derivative (PMN No. P-92-692) is subject to reporting under...
40 CFR 721.430 - Oxo-substituted amino-al-kanoic acid derivative.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxo-substituted amino-al-kanoic acid... Specific Chemical Substances § 721.430 Oxo-substituted amino-al-kanoic acid derivative. (a) Chemical... as oxo-substituted amino al-kan-oic acid derivative (PMN No. P-92-692) is subject to reporting under...
Uncovering the Lactobacillus plantarum WCFS1 Gallate Decarboxylase Involved in Tannin Degradation

PubMed Central

Jiménez, Natalia; Curiel, José Antonio; Reverón, Inés; de las Rivas, Blanca

2013-01-01

Lactobacillus plantarum is a lactic acid bacterium able to degrade tannins by the subsequent action of tannase and gallate decarboxylase enzymes. The gene encoding tannase had previously been identified, whereas the gene encoding gallate decarboxylase is unknown. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of gallic-acid induced L. plantarum extracts showed a 54-kDa protein which was absent in the uninduced cells. This protein was identified as Lp_2945, putatively annotated UbiD. Homology searches identified ubiD-like genes located within three-gene operons which encoded the three subunits of nonoxidative aromatic acid decarboxylases. L. plantarum is the only bacterium in which the lpdC (lp_2945) gene and the lpdB and lpdD (lp_0271 and lp_0272) genes are separated in the chromosome. Combination of extracts from recombinant Escherichia coli cells expressing the lpdB, lpdC, and lpdC genes demonstrated that LpdC is the only protein required to yield gallate decarboxylase activity. However, the disruption of these genes in L. plantarum revealed that the lpdB and lpdC gene products are essential for gallate decarboxylase activity. Similar to L. plantarum tannase, which exhibited activity only in esters derived from gallic and protocatechuic acids, purified His6-LpdC protein from E. coli showed decarboxylase activity against gallic and protocatechuic acids. In contrast to the tannase activity, gallate decarboxylase activity is widely present among lactic acid bacteria. This study constitutes the first genetic characterization of a gallate decarboxylase enzyme and provides new insights into the role of the different subunits of bacterial nonoxidative aromatic acid decarboxylases. PMID:23645198
Activities of arginine and ornithine decarboxylases in various plant species.

PubMed

Birecka, H; Bitonti, A J; McCann, P P

1985-10-01

In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to V(max), ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. alpha-Difluoromethylornithine and alpha-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species.No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed.In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum.
Synthesis of ω-Oxo Amino Acids and trans-5-Substituted Proline Derivatives Using Cross-Metathesis of Unsaturated Amino Acids.

PubMed

Salih, Nabaz; Adams, Harry; Jackson, Richard F W

2016-09-16

A range of 7-oxo, 8-oxo, and 9-oxo amino acids, analogues of 8-oxo-2-aminodecanoic acid, one of the key components of the cyclic tetrapeptide apicidin, have been prepared by a three-step process involving copper-catalyzed allylation of serine-, aspartic acid-, and glutamic acid-derived organozinc reagents, followed by cross-metathesis of the resulting terminal alkenes with unsaturated ketones and hydrogenation. The intermediate 7-oxo-5-enones underwent a highly diastereoselective (dr ≥96:4) acid-catalyzed aza-Michael reaction to give trans-2,5-disubstituted pyrrolidines, 5-substituted proline derivatives. The aza-Michael reaction was first observed when the starting enones were allowed to stand in solution in deuterochloroform but can be efficiently promoted by catalytic amounts of dry HCl.
Polyamines and plant stress - Activation of putrescine biosynthesis by osmotic shock

NASA Technical Reports Server (NTRS)

Flores, H. E.; Galston, A. W.

1982-01-01

The putrescine content of oat leaf cells and protoplasts increases up to 60-fold within 6 hours of exposure to osmotic stress (0.4 to 0.6 molar sorbitol). Barley, corn, wheat, and wild oat leaves show a similar response. Increased arginine decarboxylase activity parallels the rise in putrescine, whereas ornithine decarboxylase remains unchanged. DL-alpha-Difluoromethylarginine, a specific irreversible inhibitor of arginine decarboxylase, prevents the stress-induced rise in increase in arginine decarboxylase activity and putrescine synthesis, indicating the preferential activation of this pathway.

Overexpression of PAD1 and FDC1 results in significant cinnamic acid decarboxylase activity in Saccharomyces cerevisiae.

PubMed

Richard, Peter; Viljanen, Kaarina; Penttilä, Merja

2015-01-01

The S. cerevisiae PAD1 gene had been suggested to code for a cinnamic acid decarboxylase, converting trans-cinnamic acid to styrene. This was suggested for the reason that the over-expression of PAD1 resulted in increased tolerance toward cinnamic acid, up to 0.6 mM. We show that by over-expression of the PAD1 together with the FDC1 the cinnamic acid decarboxylase activity can be increased significantly. The strain over-expressing PAD1 and FDC1 tolerated cinnamic acid concentrations up to 10 mM. The cooperation of Pad1p and Fdc1p is surprising since the PAD1 has a mitochondrial targeting sequence and the FDC1 codes for a cytosolic protein. The cinnamic acid decarboxylase activity was also seen in the cell free extract. The activity was 0.019 μmol per minute and mg of extracted protein. The overexpression of PAD1 and FDC1 resulted also in increased activity with the hydroxycinnamic acids ferulic acid, p-coumaric acid and caffeinic acid. This activity was not seen when FDC1 was overexpressed alone. An efficient cinnamic acid decarboxylase is valuable for the genetic engineering of yeast strains producing styrene. Styrene can be produced from endogenously produced L-phenylalanine which is converted by a phenylalanine ammonia lyase to cinnamic acid and then by a decarboxylase to styrene.
Peroxisome proliferator-activated receptor-alpha regulates fatty acid utilization in primary human skeletal muscle cells.

PubMed

Muoio, Deborah M; Way, James M; Tanner, Charles J; Winegar, Deborah A; Kliewer, Steven A; Houmard, Joseph A; Kraus, William E; Dohm, G Lynis

2002-04-01

In humans, skeletal muscle is a major site of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) expression, but its function in this tissue is unclear. We investigated the role of hPPAR-alpha in regulating muscle lipid utilization by studying the effects of a highly selective PPAR-alpha agonist, GW7647, on [(14)C]oleate metabolism and gene expression in primary human skeletal muscle cells. Robust induction of PPAR-alpha protein expression occurred during muscle cell differentiation and corresponded with differentiation-dependent increases in oleate oxidation. In mature myotubes, 48-h treatment with 10-1,000 nmol/l GW7647 increased oleate oxidation dose-dependently, up to threefold. Additionally, GW7647 decreased oleate esterification into myotube triacylglycerol (TAG), up to 45%. This effect was not abolished by etomoxir, a potent inhibitor of beta-oxidation, indicating that PPAR-alpha-mediated TAG depletion does not depend on reciprocal changes in fatty acid catabolism. Consistent with its metabolic actions, GW7647 induced mRNA expression of mitochondrial enzymes that promote fatty acid catabolism; carnitine palmityltransferase 1 and malonyl-CoA decarboxylase increased approximately 2-fold, whereas pyruvate dehydrogenase kinase 4 increased 45-fold. Expression of several genes that regulate glycerolipid synthesis was not changed by GW7647 treatment, implicating involvement of other targets to explain the TAG-depleting effect of the compound. These results demonstrate a role for hPPAR-alpha in regulating muscle lipid homeostasis.
Neuronal nicotinic acetylcholine receptor subunits in autism: an immunohistochemical investigation in the thalamus.

PubMed

Ray, M A; Graham, A J; Lee, M; Perry, R H; Court, J A; Perry, E K

2005-08-01

The cholinergic system has been implicated in the development of autism on the basis of neuronal nicotinic acetylcholine receptor (nAChR) losses in cerebral and cerebellar cortex. In the present study, the first to explore nAChRs in the thalamus in autism, alpha4, alpha7 and beta2 nAChR subunit expression in thalamic nuclei of adult individuals with autism (n=3) and age-matched control cases (n=3) was investigated using immunochemical methods. Loss of alpha7- and beta2- (but not alpha4-) immunoreactive neurons occurred in the paraventricular nucleus (PV) and nucleus reuniens in autism. Preliminary results indicated glutamic acid decarboxylase immunoreactivity occurred at a low level in PV, co-expressed with alpha7 in normal and autistic cases and was not reduced in autism. This suggested loss of neuronal alpha7 in autism is not caused by loss of GABAergic neurons. These findings indicate nicotinic abnormalities that occur in the thalamus in autism which may contribute to sensory or attentional deficits.
High-performance liquid chromatographic method for profiling 2-oxo acids in urine and its application in evaluating vitamin status in rats.

PubMed

Shibata, Katsumi; Nakata, Chifumi; Fukuwatari, Tsutomu

2016-01-01

B-group vitamins are involved in the catabolism of 2-oxo acids. To identify the functional biomarkers of B-group vitamins, we developed a high-performance liquid chromatographic method for profiling 2-oxo acids in urine and applied this method to urine samples from rats deficient in vitamins B1 and B6 and pantothenic acid. 2-Oxo acids were reacted with 1,2-diamino-4,5-methylenebenzene to produce fluorescent derivatives, which were then separated using a TSKgel ODS-80Ts column with 30 mmol/L of KH2PO4 (pH 3.0):acetonitrile (7:3) at a flow rate of 1.0 mL/min. Vitamin B1 deficiency increased urinary levels of all 2-oxo acids, while vitamin B6 deficiency only increased levels of sum of 2-oxaloacetic acid and pyruvic acid, and pantothenic acid deficiency only increased levels of 2-oxoisovaleric acid. Profiles of 2-oxo acids in urine samples might be a non-invasive way of clarifying the functional biomarker of B-group vitamins.
Immunohistochemical detection of a substituted 1,N(2)-ethenodeoxyguanosine adduct by omega-6 polyunsaturated fatty acid hydroperoxides in the liver of rats fed a choline-deficient, L-amino acid-defined diet.

PubMed

Kawai, Yoshichika; Kato, Yoji; Nakae, Dai; Kusuoka, Osamu; Konishi, Yoichi; Uchida, Koji; Osawa, Toshihiko

2002-03-01

Endogenous lipid peroxidation products react with DNA and form exocyclic DNA adducts. The purpose of this study was to investigate the in vivo formation of 7-(2-oxo-heptyl)-substituted 1,N(2)-etheno-2'-deoxyguanosine adduct (Oxo-heptyl-varepsilondG), one of the major products from the reaction of 13-hydroperoxyoctadecadienoic acid (13-HPODE) with dG. The monoclonal antibody specific to Oxo-heptyl-varepsilondG was prepared using a chemically synthesized conjugate of Oxo-heptyl-varepsilondG and carrier protein as immunogen. The characterization showed that the obtained antibody (mAb6A3) is specific to the Oxo-heptyl-varepsilondG moiety. Using the novel antibody, the presence of the Oxo-heptyl-varepsilondG adduct in vivo was immunohistochemically revealed in the liver of rats fed a choline-deficient, L-amino acid-defined diet, an endogenous carcinogenesis model, for 3 days. In addition, the Oxo-heptyl-varepsilondG formation was confirmed in DNAs treated with peroxidized linoleic acid, arachidonic acid and gamma-linolenic acid, respectively, suggesting that the hydroperoxides of omega-6 polyunsaturated fatty acids could be the potential sources of Oxo-heptyl-varepsilondG formation in vivo. Collectively, the results in this study suggest the first evidence that the formation of Oxo-heptyl-varepsilondG, the omega-6 lipid hydroperoxide-mediated DNA adduct, may be a potential biomarker for the early phase of carcinogenesis.
40 CFR 180.426 - 2-[4,5-Dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid; tolerance for residues. 180.426 Section 180...-Dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid; tolerance for...)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid, in or on the raw agricultural commodity soybean...
Expression of Ornithine Decarboxylase Is Transiently Increased by Pollination, 2,4-Dichlorophenoxyacetic Acid, and Gibberellic Acid in Tomato Ovaries1

PubMed Central

Alabadí, David; Carbonell, Juan

1998-01-01

A cDNA encoding for a functional ornithine decarboxylase has been isolated from a cDNA library of carpels of tomato (Lycopersicon esculentum Mill.). Ornithine decarboxylase in tomato is represented by a single-copy gene that we show to be up-regulated during early fruit growth induced by 2,4-dichlorophenoxyacetic acid and gibberellic acid. PMID:9733552
Sensing and adaptation to low pH mediated by inducible amino acid decarboxylases in Salmonella.

PubMed

Viala, Julie P M; Méresse, Stéphane; Pocachard, Bérengère; Guilhon, Aude-Agnès; Aussel, Laurent; Barras, Frédéric

2011-01-01

During the course of infection, Salmonella enterica serovar Typhimurium must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments. Three low pH inducible amino acid decarboxylases were annotated in the genome of S. Typhimurium, AdiA, CadA and SpeF, which are specific for arginine, lysine and ornithine, respectively. In this study, we characterized and compared the contributions of those enzymes in response to acidic challenges. Individual mutants as well as a strain deleted for the three genes were tested for their ability (i) to survive an extreme acid shock, (ii) to grow at mild acidic pH and (iii) to infect the mouse animal model. We showed that the lysine decarboxylase CadA had the broadest range of activity since it both had the capacity to promote survival at pH 2.3 and growth at pH 4.5. The arginine decarboxylase AdiA was the most performant in protecting S. Typhimurium from a shock at pH 2.3 and the ornithine decarboxylase SpeF conferred the best growth advantage under anaerobiosis conditions at pH 4.5. We developed a GFP-based gene reporter to monitor the pH of the environment as perceived by S. Typhimurium. Results showed that activities of the lysine and ornithine decarboxylases at mild acidic pH did modify the local surrounding of S. Typhimurium both in culture medium and in macrophages. Finally, we tested the contribution of decarboxylases to virulence and found that these enzymes were dispensable for S. Typhimurium virulence during systemic infection. In the light of this result, we examined the genomes of Salmonella spp. normally responsible of systemic infection and observed that the genes encoding these enzymes were not well conserved, supporting the idea that these enzymes may be not required during systemic infection.
Phenotypic and genetic evaluations of biogenic amine production by lactic acid bacteria isolated from fish and fish products.

PubMed

Muñoz-Atienza, Estefanía; Landeta, Gerardo; de las Rivas, Blanca; Gómez-Sala, Beatriz; Muñoz, Rosario; Hernández, Pablo E; Cintas, Luis M; Herranz, Carmen

2011-03-30

In this work, biogenic amine production (histamine, tyramine and putrescine) by a collection of 74 lactic acid bacteria of aquatic origin has been investigated by means of amino acid decarboxylation by growth on decarboxylase differential medium, biogenic amine detection by thin-layer chromatography (TLC) and decarboxylase gene detection by PCR. None of the evaluated strains showed neither production of histamine and putrescine, nor presence of the genetic determinants encoding the corresponding decarboxylase activities. However, the tyrosine decarboxylase gene (tdc) was present in all the enterococcal strains, and tyramine production was detected by TLC in all of them but Enterococcus faecium BCS59 and MV5. Analysis of the tyrosine decarboxylase operon of these strains revealed the presence of an insertion sequence upstream tdc that could be responsible for their lack of tyrosine decarboxylase activity. Copyright © 2011 Elsevier B.V. All rights reserved.
Effects of clofibric acid on the activity and activity state of the hepatic branched-chain 2-oxo acid dehydrogenase complex.

PubMed Central

Zhao, Y; Jaskiewicz, J; Harris, R A

1992-01-01

Feeding clofibric acid to rats caused little or no change in total activity of the liver branched-chain 2-oxo acid dehydrogenase complex (BCODC). No change in mass of liver BCODC was detected by immunoblot analysis in response to dietary clofibric acid. No changes in abundance of mRNAs for the BCODC E1 alpha, E1 beta and E2 subunits were detected by Northern-blot analysis. Likewise, dietary clofibric acid had no effect on the activity state of liver BCODC (percentage of enzyme in the dephosphorylated, active, form) of rats fed on a chow diet. However, dietary clofibric acid greatly increased the activity state of liver BCODC of rats fed on a diet deficient in protein. No stable change in liver BCODC kinase activity was found in response to clofibric acid in either chow-fed or low-protein-fed rats. Clofibric acid had a biphasic effect on flux through BCODC in hepatocytes prepared from low-protein-fed rats. Stimulation of BCODC flux at low concentrations was due to clofibric acid inhibition of BCODC kinase, which in turn allowed activation of BCODC by BCODC phosphatase. Inhibition of BCODC flux at high concentrations was due to direct inhibition of BCODC by clofibric acid. The results suggest that the effects of clofibric acid in vivo on branched-chain amino acid metabolism can be explained by the inhibitory effects of this drug on BCODC kinase. Images Fig. 2. Fig. 3. PMID:1637295
Bile acids and their oxo derivatives: Potential inhibitors of carbonic anhydrase I and II, androgen receptor antagonists and CYP3A4 substrates.

PubMed

Trifunović, Jovana; Borčić, Vladan; Mikov, Momir

2017-05-01

Some biological properties of bile acids and their oxo derivatives have not been sufficiently investigated, although the interest in bile acids as signaling molecules is rising. The aim of this work was to evaluate physico-chemical parametar b (slope) that represents the lipophilicity of the examined molecules and to investigate interactions of bile acids with carbonic anhydrase I, II, androgen receptor and CYP450s. Thirteen candidates were investigated using normal-phase thin-layer chromatography in two solvent systems. Retention parameters were used in further quantitative structure-activity relationship analysis and docking studies to predict interactions and binding affinities of examined molecules with enzymes and receptors. Prediction of activity on androgen receptor showed that compounds 3α-hydroxy-12-oxo-5β-cholanoic and 3α-hydroxy-7-oxo-5β-cholanoic acid have stronger antiandrogen activity than natural bile acids. The inhibitory potential for carbonic anhydrase I and II was tested and it was concluded that molecules 3α-hydroxy-12-oxo-5β-cholanoic, 3α-hydroxy-7-oxo-5β-cholanoic, 3,7,12-trioxo-5β-cholanoic acid and hyodeoxycholic acid show the best results. Substrate behavior for CYP3A4 was confirmed for all investigated compounds. Oxo derivatives of bile acids show stronger interactions with enzymes and receptors as classical bile acids and lower membranolytic activity compared with them. These significant observations could be valuable in consideration of oxo derivatives as building blocks in medicinal chemistry. Copyright © 2016 John Wiley & Sons, Ltd.
Screening method for detection of immediate amino acid decarboxylases--producing bacteria implicated in food poisoning.

PubMed

Hussain, Husniza; Mohd Fuat, A R; Vimala, B; Ghazali, H M

2011-08-01

Assessment of amino acid decarboxylase activity can be conducted using tubed broth or plated agar. In this study, the test was carried out in microtitre plates containing lysine, ornithine, arginine, tyrosine, tryptophan, phenylalanine or histidine as biogenic amine precursors. Møller decarboxylase base broth (MDB) with or without 1% of a known amino acid were added to wells of a 96 well-microtitre plate. The wells were inoculated with Escherichia coli, Klebsiella pneumoniae, Acinetobacter anitratus or Staphylococcus aureus to the final concentration of 6.0 x 10(7) cfu/ml and incubated at 35ºC. The absorbance of the culture broth was read at 570 nm at 0, 1.0, 2.0, 3.0, 4.0, 5.5, 6.5 and 7.5 hour. Comparison of means of A'(570) between 0 hour and a specified incubation time was determined statistically. Positive decarboxylase activities were detected in the media inoculated with E. coli and K. pneumoniae in less than 6 hours. The current method is suitable for immediate producers of amino acid decarboxylase enzymes. It costs less as it uses less amino acid and it has the potential to be used for screening aliquots of food materials for amino acid decarboxylase activities.
The ygeW encoded protein from Escherichia coli is a knotted ancestral catabolic transcarbamylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yongdong; Jin, Zhongmin; Yu, Xiaolin

Purine degradation plays an essential role in nitrogen metabolism in most organisms. Uric acid is the final product of purine catabolism in humans, anthropoid apes, birds, uricotelic reptiles, and almost all insects. Elevated levels of uric acid in blood (hyperuricemia) cause human diseases such as gout, kidney stones, and renal failure. Although no enzyme has been identified that further degrades uric acid in humans, it can be oxidized to produce allantoin by free-radical attack. Indeed, elevated levels of allantoin are found in patients with rheumatoid arthritis, chronic lung disease, bacterial meningitis, and noninsulin-dependent diabetes mellitus. In other mammals, some insectsmore » and gastropods, uric acid is enzymatically degraded to the more soluble allantoin through the sequential action of three enzymes: urate oxidase, 5-hydroxyisourate (HIU) hydrolase and 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) decarboxylase. Therefore, an elective treatment for acute hyperuricemia is the administration of urate oxidase. Many organisms, including plants, some fungi and several bacteria, are able to catabolize allantoin to release nitrogen, carbon, and energy. In Arabidopsis thaliana and Eschrichia coli, S-allantoin has recently been shown to be degraded to glycolate and urea by four enzymes: allantoinase, allantoate amidohydrolase, ureidoglycine aminohydrolase, and ureidoglycolate amidohydrolase.« less
Computational study on the aminolysis of beta-hydroxy-alpha,beta-unsaturated ester via the favorable path including the formation of alpha-oxo ketene intermediate.

PubMed

Jin, Lu; Xue, Ying; Zhang, Hui; Kim, Chan Kyung; Xie, Dai Qian; Yan, Guo Sen

2008-05-15

The possible mechanisms of the aminolysis of N-methyl-3-(methoxycarbonyl)-4-hydroxy-2-pyridone (beta-hydroxy-alpha,beta-unsaturated ester) with dimethylamine are investigated at the hybrid density functional theory B3LYP/6-31G(d,p) level in the gas phase. Single-point computations at the B3LYP/6-311++G(d,p) and the Becke88-Becke95 1-parameter model BB1K/6-311++G(d,p) levels are performed for more precise energy predictions. Solvent effects are also assessed by single-point calculations at the integral equation formalism polarized continuum model IEFPCM-B3LYP/6-311++G(d,p) and IEFPCM-BB1K/6-311++G(d,p) levels on the gas-phase optimized geometries. Three possible pathways, the concerted pathway (path A), the stepwise pathway involving tetrahedral intermediates (path B), and the stepwise pathway via alpha-oxo ketene intermediate due to the participation of beta-hydroxy (path C), are taken into account for the title reaction. Moreover, path C includes two sequential processes. The first process is to generate alpha-oxo ketene intermediate via the decomposition of N-methyl-3-(methoxycarbonyl)-4-hydroxy-2-pyridone; the second process is the addition of dimethylamine to alpha-oxo ketene intermediate. Our results indicate that path C is more favorable than paths A and B both in the gas phase and in solvent (heptane). In path C, the first process is the rate-determining step, and the second process is revealed to be a [4+2] pseudopericyclic reaction without the energy barrier. Being independent of the concentration of amine, the first process obeys the first-order rate law.
Merging Photoredox and Nickel Catalysis: The Direct Synthesis of Ketones via the Decarboxylative Arylation of α-Oxo Acids**

PubMed Central

Chu, Lingling; Lipshultz, Jeffrey M.

2015-01-01

The direct decarboxylative arylation of α-oxo acids has been achieved via synergistic visible light-mediated photoredox and nickel catalyses. This method offers rapid entry to aryl and alkyl ketone architectures from simple α-oxo acid precursors via an acyl radical intermediate. Significant substrate scope is observed with respect to both the oxo acid and arene coupling partners. This mild decarboxylative arylation can also be utilized to efficiently access medicinal agents, as demonstrated by the rapid synthesis of fenofibrate. PMID:26014029
Functional characterization of Arabidopsis thaliana transthyretin-like protein.

PubMed

Pessoa, João; Sárkány, Zsuzsa; Ferreira-da-Silva, Frederico; Martins, Sónia; Almeida, Maria R; Li, Jianming; Damas, Ana M

2010-02-18

Arabidopsis thaliana transthyretin-like (TTL) protein is a potential substrate in the brassinosteroid signalling cascade, having a role that moderates plant growth. Moreover, sequence homology revealed two sequence domains similar to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) decarboxylase (N-terminal domain) and 5-hydroxyisourate (5-HIU) hydrolase (C-terminal domain). TTL is a member of the transthyretin-related protein family (TRP), which comprises a number of proteins with sequence homology to transthyretin (TTR) and the characteristic C-terminal sequence motif Tyr-Arg-Gly-Ser. TRPs are single domain proteins that form tetrameric structures with 5-HIU hydrolase activity. Experimental evidence is fundamental for knowing if TTL is a tetrameric protein, formed by the association of the 5-HIU hydrolase domains and, in this case, if the structural arrangement allows for OHCU decarboxylase activity. This work reports about the biochemical and functional characterization of TTL. The TTL gene was cloned and the protein expressed and purified for biochemical and functional characterization. The results show that TTL is composed of four subunits, with a moderately elongated shape. We also found evidence for 5-HIU hydrolase and OHCU decarboxylase activities in vitro, in the full-length protein. The Arabidopsis thaliana transthyretin-like (TTL) protein is a tetrameric bifunctional enzyme, since it has 5-HIU hydrolase and OHCU decarboxylase activities, which were simultaneously observed in vitro.
Inhibition of lipopolysaccharide-induced inducible nitric oxide synthase and cyclooxygenase-2 expression by xanthanolides isolated from Xanthium strumarium.

PubMed

Yoon, Jeong Hoon; Lim, Hyo Jin; Lee, Hwa Jin; Kim, Hee-Doo; Jeon, Raok; Ryu, Jae-Ha

2008-03-15

Three sesquiterpenoids, xanthatin (1), xanthinosin (2), and 4-oxo-bedfordia acid (3) were isolated from Xanthium strumarium as inhibitors of nitric oxide synthesis in activated microglia (IC(50) values: 0.47, 11.2, 136.5 microM, respectively). Compounds 1 and 2 suppressed the expression of iNOS and COX-2 and the activity of NF-kappaB through the inhibition of LPS-induced I-kappaB-alpha degradation in microglia.
A maize death acid, 10-oxo-11-phytoenoic acid, is the predominant cyclopentenone signal present during multiple stress and developmental conditions

USDA-ARS?s Scientific Manuscript database

Recently we investigated the function of the 9-lipoxygenase (LOX) derived cyclopentenones 10-oxo-11-phytoenoic acid (10-OPEA) and 10-oxo-11-phytodienoic acid (10-OPDA) and identified their C-14 and C-12 derivatives. 10-OPEA accumulation is elicited by fungal and insect attack and acts as a strong in...
Space flight and oxidative stress

NASA Technical Reports Server (NTRS)

Stein, T. P.

2002-01-01

Space flight is associated with an increase in oxidative stress after return to 1g. The effect is more pronounced after long-duration space flight. The effects lasts for several weeks after landing. In humans there is increased lipid peroxidation in erythrocyte membranes, reduction in some blood antioxidants, and increased urinary excretion of 8-iso-prostaglandin F(2alpha) and 8-oxo-7,8 dihydro-2 deoxyguanosine. Isoprostane 8-iso-prostaglandin F(2alpha) and 8-oxo-7,8 dihydro-2 deoxyguanosine are markers for oxidative damage to lipids and DNA, respectively. The changes have been attributed to a combination of the energy deficiency that occurs during flight and substrate competition for amino acids occurring between repleting muscle and other tissues during the recovery phase. The observations in humans have been complemented by rodent studies. Most rodent studies showed increased production of lipid peroxidation products postflight and decreased antioxidant enzyme activity postflight. The rodent observations were attributed to the stress associated with reentry into Earth's gravity. Decreasing the imbalance between the production of endogenous oxidant defenses and oxidant production by increasing the supply of dietary antioxidants may lessen the severity of the postflight increase in oxidative stress.
An endogenous factor enhances ferulic acid decarboxylation catalyzed by phenolic acid decarboxylase from Candida guilliermondii

PubMed Central

2012-01-01

The gene for a eukaryotic phenolic acid decarboxylase of Candida guilliermondii was cloned, sequenced, and expressed in Escherichia coli for the first time. The structural gene contained an open reading frame of 504 bp, corresponding to 168 amino acids with a calculated molecular mass of 19,828 Da. The deduced amino sequence exhibited low similarity to those of functional phenolic acid decarboxylases previously reported from bacteria with 25-39% identity and to those of PAD1 and FDC1 proteins from Saccharomyces cerevisiae with less than 14% identity. The C. guilliermondii phenolic acid decarboxylase converted the main substrates ferulic acid and p-coumaric acid to the respective corresponding products. Surprisingly, the ultrafiltrate (Mr 10,000-cut-off) of the cell-free extract of C. guilliermondii remarkably activated the ferulic acid decarboxylation by the purified enzyme, whereas it was almost without effect on the p-coumaric acid decarboxylation. Gel-filtration chromatography of the ultrafiltrate suggested that an endogenous amino thiol-like compound with a molecular weight greater than Mr 1,400 was responsible for the activation. PMID:22217315

Characterization and evaluation of an oral microemulsion containing the antitumor diterpenoid compound ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid.

PubMed

Lu, Yingnian; Wu, Kefeng; Li, Li; He, Yuhui; Cui, Liao; Liang, Nianci; Mu, Bozhong

2013-01-01

The objective of this study was to develop an oral microemulsion formulation of the antitumor diterpenoid agent, ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (henceforth referred to as 5F), to enhance its bioavailability and evaluate its hepatotoxicity. Pseudoternary phase diagrams showed that the optimal microemulsion formulation contained 45% water, 10% castor oil as the oil phase, 15% Cremophor EL as the surfactant, and 30% as a cosurfactant mixture of 1,2-propanediol and polyethylene glycol (PEG)-400 (2:1, w/w). The microemulsion preparation was characterized and its droplet diameter was within 50 nm. Release of 5F in vitro from the microemulsion was slightly increased compared with a suspension containing the same amount of active drug. Pharmacokinetic parameters in vivo indicated that bioavailability was markedly improved, with the relative bioavailability being 616.15% higher for the microemulsion than for the suspension. Toxicity tests showed that the microemulsion had no hepatotoxicity in mice. These results suggest the potential for 5F microemulsion to be administered by the oral route.
The Degradation of 14C-Glutamic Acid by L-Glutamic Acid Decarboxylase.

ERIC Educational Resources Information Center

Dougherty, Charles M; Dayan, Jean

1982-01-01

Describes procedures and semi-micro reaction apparatus (carbon dioxide trap) to demonstrate how a particular enzyme (L-Glutamic acid decarboxylase) may be used to determine the site or sites of labeling in its substrate (carbon-14 labeled glutamic acid). Includes calculations, solutions, and reagents used. (Author/SK)
Mixed micelles of 7,12-dioxolithocholic acid and selected hydrophobic bile acids: interaction parameter, partition coefficient of nitrazepam and mixed micelles haemolytic potential.

PubMed

Poša, Mihalj; Tepavčević, Vesna

2011-09-01

The formation of mixed micelles built of 7,12-dioxolithocholic and the following hydrophobic bile acids was examined by conductometric method: cholic (C), deoxycholic (D), chenodeoxycholic (CD), 12-oxolithocholic (12-oxoL), 7-oxolithocholic (7-oxoL), ursodeoxycholic (UD) and hiodeoxycholic (HD). Interaction parameter (β) in the studied binary mixed micelles had negative value, suggesting synergism between micelle building units. Based on β value, the hydrophobic bile acids formed two groups: group I (C, D and CD) and group II (12-oxoL, 7-oxoL, UD and HD). Bile acids from group II had more negative β values than bile acids from group I. Also, bile acids from group II formed intermolecular hydrogen bonds in aggregates with both smaller (2) and higher (4) aggregation numbers, according to the analysis of their stereochemical (conformational) structures and possible structures of mixed micelles built of these bile acids and 7,12-dioxolithocholic acid. Haemolytic potential and partition coefficient of nitrazepam were higher in mixed micelles built of the more hydrophobic bile acids (C, D, CD) and 7,12-dioxolithocholic acid than in micelles built only of 7,12-dioxolithocholic acid. On the other hand, these mixed micelles still had lower values of haemolytic potential than micelles built of C, D or CD. The mixed micelles that included bile acids: 12-oxoL, 7-oxoL, UD or HD did not significantly differ from the micelles of 7,12-dioxolithocholic acid, observing the values of their haemolytic potential. Copyright © 2011 Elsevier B.V. All rights reserved.
Novel Mechanism of Fatty Acid Sensing in Enteroendocrine Cells: Specific Structures in Oxo-Fatty Acids Produced by Gut Bacteria are Responsible for CCK Secretion in STC-1 Cells via GPR40.

PubMed

Hira, Tohru; Ogasawara, Shono; Yahagi, Asuka; Kamachi, Minami; Li, Jiaxin; Nishimura, Saki; Sakaino, Masayoshi; Yamashita, Takatoshi; Kishino, Shigenobu; Ogawa, Jun; Hara, Hiroshi

2018-06-25

The secretion of gut hormones, such as cholecystokinin (CCK) is stimulated by fatty acids. Although a chain length-dependent mechanism has been proposed, other structural relationships to releasing activity remain unclear. We aimed to elucidate specific structures in fatty acids that are responsible for their CCK-releasing activity, and related sensing mechanisms in enteroendocrine cells. We examined CCK secretory activities in a murine CCK-producing cell line STC-1 by exposing the cells to various modified fatty acids produced by gut lactic acid bacteria. The effects of fatty acids on gastric emptying rate as a CCK-mediated function were examined using acetaminophen- and phenol red-methods in rats. Out of more than thirty octadecanoic (C18)-derived fatty acids tested, five oxo-fatty acids potently stimulated CCK secretion without cytotoxic effects in STC-1 cells. Three fatty acids had a distinct specific structure containing one double-bond, whereas the other two had two double-bonds, nearby an oxo residue. CCK secretion induced by representative fatty acids (10-oxo-trans-11-18:1 and 13-oxo-cis-9,cis-15-18:2) was attenuated by a fatty acid-receptor GPR40 antagonist. Oral administration of 13-oxo-cis-9,cis-15-18:2 lowered the gastric emptying rate in rats in a dose- and structure-dependent manner. These results revealed a novel fatty acid-sensing mechanism in enteroendocrine cells. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Molecular analysis of the glutamate decarboxylase locus in Streptococcus thermophilus ST110

USDA-ARS?s Scientific Manuscript database

GABA ('-aminobutyric acid) is generated from glutamate by the action of glutamic acid decarboxylase (GAD) and characterized by hypotensive, diuretic and tranquilizing effects in humans and animals. The production of GABA by lactic acid starter bacteria would enhance the functionality of fermented da...
Detection and transfer of the glutamate decarboxylase gene in Streptococcus thermophilus

USDA-ARS?s Scientific Manuscript database

GABA (gamma-aminobutyric acid) is generated from glutamate by the action of glutamic acid decarboxylase (GAD) and characterized by hypotensive, diuretic and tranquilizing effects in humans and animals. The production of GABA by lactic acid starter bacteria would enhance the functionality of fermen...
Cloning and sequencing of pyruvate decarboxylase (PDC) genes from bacteria and uses therefor

DOEpatents

Maupin-Furlow, Julie A [Gainesville, FL; Talarico, Lee Ann [Gainesville, FL; Raj, Krishnan Chandra [Tamil Nadu, IN; Ingram, Lonnie O [Gainesville, FL

2008-02-05

The invention provides isolated nucleic acids molecules which encode pyruvate decarboxylase enzymes having improved decarboxylase activity, substrate affinity, thermostability, and activity at different pH. The nucleic acids of the invention also have a codon usage which allows for high expression in a variety of host cells. Accordingly, the invention provides recombinant expression vectors containing such nucleic acid molecules, recombinant host cells comprising the expression vectors, host cells further comprising other ethanologenic enzymes, and methods for producing useful substances, e.g., acetaldehyde and ethanol, using such host cells.
Enhancing muconic acid production from glucose and lignin-derived aromatic compounds via increased protocatechuate decarboxylase activity

DOE PAGES

Johnson, Christopher W.; Salvachua, Davinia; Khanna, Payal; ...

2016-04-22

The conversion of biomass-derived sugars and aromatic molecules to cis,cis-muconic acid (referred to hereafter as muconic acid or muconate) has been of recent interest owing to its facile conversion to adipic acid, an important commodity chemical. Metabolic routes to produce muconate from both sugars and many lignin-derived aromatic compounds require the use of a decarboxylase to convert protocatechuate (PCA, 3,4-dihydroxybenzoate) to catechol (1,2-dihydroxybenzene), two central aromatic intermediates in this pathway. Several studies have identified the PCA decarboxylase as a metabolic bottleneck, causing an accumulation of PCA that subsequently reduces muconate production. A recent study showed that activity of the PCAmore » decarboxylase is enhanced by co-expression of two genetically associated proteins, one of which likely produces a flavin-derived cofactor utilized by the decarboxylase. Using entirely genome-integrated gene expression, we have engineered Pseudomonas putida KT2440-derived strains to produce muconate from either aromatic molecules or sugars and demonstrate in both cases that co-expression of these decarboxylase associated proteins reduces PCA accumulation and enhances muconate production relative to strains expressing the PCA decarboxylase alone. In bioreactor experiments, co-expression increased the specific productivity (mg/g cells/h) of muconate from the aromatic lignin monomer p-coumarate by 50% and resulted in a titer of >15 g/L. In strains engineered to produce muconate from glucose, co-expression more than tripled the titer, yield, productivity, and specific productivity, with the best strain producing 4.92+/-0.48 g/L muconate. Furthermore, this study demonstrates that overcoming the PCA decarboxylase bottleneck can increase muconate yields from biomass-derived sugars and aromatic molecules in industrially relevant strains and cultivation conditions.« less
Inhibition, by 2-oxo acids that accumulate in maple-syrup-urine disease, of lactate, pyruvate, and 3-hydroxybutyrate transport across the blood-brain barrier.

PubMed

Cremer, J E; Teal, H M; Cunningham, V J

1982-09-01

Data are presented in support of the transport of (-)-D-3-hydroxybutyrate across the blood-brain barrier (BBB) being a carrier-mediated process. The kinetic parameters in 21-day-old pentobarbital-anaesthetized rats were Vmax 2.0 mumol.g-1.min-1, Km 29 mM, and KD 0.024 ml.g-1.min-1. The value for Vmax was the same as that for L-lactate and pyruvate transport in animals of the same age. The transport of all three substrates was sensitive to inhibition by low concentrations of either 2-oxo-3-methylbutanoate or 2-oxo-4-methylpentanoate, the 2-oxo acids that can accumulate in patients with maple-syrup-urine disease. The Ki values for the 2-oxo acids were severalfold lower than the respective Km values. 2-Oxo-3-phenylpropionate was a poor inhibitor. The relative affinities of the various monocarboxylic acids for the transport system of the BBB distinguished it from similar systems described in brain, heart, and liver mitochondria; human erythrocytes; and Ehrlich ascites-tumour cells.
Self and viral peptides can initiate lysis by autologous natural killer cells.

PubMed

Mandelboim, O; Wilson, S B; Valés-Gómez, M; Reyburn, H T; Strominger, J L

1997-04-29

Natural killer (NK) cells are inhibited by specific allotypes of class I major histocompatibility complex ligands recognized by polymorphic inhibitory receptors (e.g., NKIR1 and NKIR2). NK1- and NK2-specific clones recognize two groups of HLA-C allotypes that are distinguished by a dimorphism at residue 80 in the alpha1 helix (alphaLys-80 and alphaAsn-80, respectively). "Empty" HLA-Cw7 expressed in peptide transporter-deficient cells and HLA-Cw7 loaded with several peptides each functioned as inhibitory ligands for NK2 lines and clones. However, loading of HLA-Cw7 with two other peptides derived from glutamic acid decarboxylase or coxsackie virus (each of which has been associated with autoimmune diabetes mellitus) abrogated this inhibitory recognition. Both peptides contained Lys at P8 of the epitope. Substitution of P8 with Ala or two other basic amino acids, His and Arg, resulted in peptides that were inhibitory, as were peptides with P8 Val, Glu, or Asn. The manner in which a Lys at P8 might affect recognition is discussed, together with a hypothesis for a novel mechanism by which an autoimmune disease might be initiated.
Systemic oxidoreductive balance and vascular function in individuals without clinical manifestation of atherosclerosis

PubMed Central

Majer, Marcin; Gackowski, Daniel; Różalski, Rafał; Siomek-Górecka, Agnieszka; Oliński, Ryszard; Budzyński, Jacek

2017-01-01

Introduction Endothelial dysfunction is recognized as the earliest disorder in the development of atherosclerosis, in the pathogenesis of which oxidative stress plays a crucial role. The aim of this study was to determine the relationships between non-invasive parameters of vascular dysfunction and oxidative stress. Material and methods Forty-eight individuals without clinical manifestation of atherosclerosis were studied. The plasma concentrations of the following were determined in all 48 subjects: retinol, ascorbic acid, α-tocopherol and uric acid, as well as the products of oxidative DNA damage repair: 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG) in blood leukocytes and urine, and 8-oxo-7,8-dihydroguanine (8-oxoGua) in urine. The following parameters of vascular dysfunction were also examined: flow- (FMD) and nitroglycerin- (NMD) mediated dilatation of the brachial artery, pulse pressure (PP), distensibility coefficient (DC), pulsation (PI) and resistance (RI) index, carotid intima-media thickness (cIMT), and ankle-brachial index (ABI). Results Individuals with an FMD value of ≥ 8.8% had significantly higher blood concentrations of antioxidative vitamins and lower concentrations of 8-oxodG in their urine and blood leukocytes than their counterparts. Blood concentration of alpha-tocopherol or ascorbic acid positively correlated with FMD, PI, RI, DC and ABI and negatively with PP and cIMT. The reverse was the case for 8-oxodG in urine and leukocytes. In multiple regression analysis, markers of oxidative DNA damage positively determined the variance in PP and ABI. Conclusions In persons without clinical manifestation of atherosclerosis, oxidative stress was an independent factor associated with vascular wall dysfunction, and a better predictor than smoking and blood concentrations of glucose, lipids and creatinine. PMID:29242843
Metabolic characteristics of 13-cis-retinoic acid (isotretinoin) and anti-tumour activity of the 13-cis-retinoic acid metabolite 4-oxo-13-cis-retinoic acid in neuroblastoma

PubMed Central

Sonawane, Poonam; Cho, Hwang Eui; Tagde, Ashujit; Verlekar, Dattesh; Yu, Alice L; Reynolds, C Patrick; Kang, Min H

2014-01-01

Background and Purpose Isotretinoin (13-cis-retinoic acid; 13-cRA) is a differentiation inducer used to treat minimal residual disease after myeloablative therapy for high-risk neuroblastoma. However, more than 40% of children develop recurrent disease during or after 13-cRA treatment. The plasma concentrations of 13-cRA in earlier studies were considered subtherapeutic while 4-oxo-13-cis-RA (4-oxo-13-cRA), a metabolite of 13-cRA considered by some investigators as inactive, were greater than threefold higher than 13-cRA. We sought to define the metabolic pathways of 13-cRA and investigated the anti-tumour activity of its major metabolite, 4-oxo-13-cRA. Experimental Approach Effects of 13-cRA and 4-oxo-13-cRA on human neuroblastoma cell lines were assessed by DIMSCAN and flow cytometry for cell proliferation, MYCN down-regulation by reverse transcription PCR and immunoblotting, and neurite outgrowth by confocal microscopy. 13-cRA metabolism was determined using tandem MS in human liver microsomes and in patient samples. Key Results Six major metabolites of 13-cRA were identified in patient samples. Of these, 4-oxo-13-cRA was the most abundant, and 4-oxo-13-cRA glucuronide was also detected at a higher level in patients. CYP3A4 was shown to play a major role in catalysing 13-cRA to 4-oxo-13-cRA. In human neuroblastoma cell lines, 4-oxo-13-cRA and 13-cRA were equi-effective at inducing neurite outgrowth, inhibiting proliferation, decreasing MYCN mRNA and protein, and increasing the expression of retinoic acid receptor-β mRNA and protein levels. Conclusions and Implications We showed that 4-oxo-13-cRA is as active as 13-cRA against neuroblastoma cell lines. Plasma levels of both 13-cRA and 4-oxo-13-cRA should be evaluated in pharmacokinetic studies of isotretinoin in neuroblastoma. PMID:25039756
Metabolic characteristics of 13-cis-retinoic acid (isotretinoin) and anti-tumour activity of the 13-cis-retinoic acid metabolite 4-oxo-13-cis-retinoic acid in neuroblastoma.

PubMed

Sonawane, Poonam; Cho, Hwang Eui; Tagde, Ashujit; Verlekar, Dattesh; Yu, Alice L; Reynolds, C Patrick; Kang, Min H

2014-12-01

Isotretinoin (13-cis-retinoic acid; 13-cRA) is a differentiation inducer used to treat minimal residual disease after myeloablative therapy for high-risk neuroblastoma. However, more than 40% of children develop recurrent disease during or after 13-cRA treatment. The plasma concentrations of 13-cRA in earlier studies were considered subtherapeutic while 4-oxo-13-cis-RA (4-oxo-13-cRA), a metabolite of 13-cRA considered by some investigators as inactive, were greater than threefold higher than 13-cRA. We sought to define the metabolic pathways of 13-cRA and investigated the anti-tumour activity of its major metabolite, 4-oxo-13-cRA. Effects of 13-cRA and 4-oxo-13-cRA on human neuroblastoma cell lines were assessed by DIMSCAN and flow cytometry for cell proliferation, MYCN down-regulation by reverse transcription PCR and immunoblotting, and neurite outgrowth by confocal microscopy. 13-cRA metabolism was determined using tandem MS in human liver microsomes and in patient samples. Six major metabolites of 13-cRA were identified in patient samples. Of these, 4-oxo-13-cRA was the most abundant, and 4-oxo-13-cRA glucuronide was also detected at a higher level in patients. CYP3A4 was shown to play a major role in catalysing 13-cRA to 4-oxo-13-cRA. In human neuroblastoma cell lines, 4-oxo-13-cRA and 13-cRA were equi-effective at inducing neurite outgrowth, inhibiting proliferation, decreasing MYCN mRNA and protein, and increasing the expression of retinoic acid receptor-β mRNA and protein levels. We showed that 4-oxo-13-cRA is as active as 13-cRA against neuroblastoma cell lines. Plasma levels of both 13-cRA and 4-oxo-13-cRA should be evaluated in pharmacokinetic studies of isotretinoin in neuroblastoma. © 2014 The British Pharmacological Society.
In vivo inhibition of polyamine biosynthesis and growth in tobacco ovary tissues

NASA Technical Reports Server (NTRS)

Slocum, R. D.; Galston, A. W.

1985-01-01

Post fertilization growth of tobacco ovary tissues treated with inhibitors of polyamine (PA) biosynthesis was examined in relation to endogenous PA titers and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17). DL-alpha-Difluoromethylornithine (DFMO) and DL-alpha-difluoromethylarginine (DFMA), specific, irreversible ("suicide") inhibitors of ODC and ADC in vitro, were used to modulate PA biosynthesis in excised flowers. ODC represented >99% of the total decarboxylase activity in tobacco ovaries. In vivo inhibition of ODC with DFMO resulted in a significant decrease in PA titers, ovary fresh weight and protein content. Simultaneous inhibition of both decarboxylases by DFMO and DFMA produced only a marginally greater depression in growth and PA titers, indicating that ODC activity is rate-limiting for PA biosynthesis in these tissues. Paradoxically, DFMA alone inhibited PA biosynthesis, not as a result of a specific inhibition of ADC, but primarily through the inactivation of ODC. In vivo inhibition of ODC by DFMA appears to result from arginase-mediated hydrolysis of this inhibitor to urea and DFMO, the suicide substrate for ODC. Putrescine conjugates in tobacco appear to function as a storage form of this amine which, upon hydrolysis, may contribute to Put homeostasis during growth.
Mutation of the oxaloacetate decarboxylase gene of Lactococcus lactis subsp. lactis impairs the growth during citrate metabolism.

PubMed

Augagneur, Y; Garmyn, D; Guzzo, J

2008-01-01

Citrate metabolism generates metabolic energy through the generation of a membrane potential and a pH gradient. The purpose of this work was to study the influence of oxaloacetate decarboxylase in citrate metabolism and intracellular pH maintenance in relation to acidic conditions. A Lactococcus lactis oxaloacetate decarboxylase mutant [ILCitM (pFL3)] was constructed by double homologous recombination. During culture with citrate, and whatever the initial pH, the growth rate of the mutant was lower. In addition, the production of diacetyl and acetoin was altered in the mutant strain. However, our results indicated no relationship with a change in the maintenance of intracellular pH. Experiments performed on resting cells clearly showed that oxaloacetate accumulated temporarily in the supernatant of the mutant. This accumulation could be involved in the perturbations observed during citrate metabolism, as the addition of oxaloacetate in M17 medium inhibited the growth of L. lactis. The mutation of oxaloacetate decarboxylase perturbed citrate metabolism and reduced the benefits of its utilization during growth under acidic conditions. This study allows a better understanding of citrate metabolism and the role of oxaloacetate decarboxylase in the tolerance of lactic acid bacteria to acidic conditions.
Rigid Dipeptide Mimics: Synthesis of Enantiopure 5- and 7-Benzyl and 5,7-Dibenzyl Indolizidinone Amino Acids via Enolization and Alkylation of delta-Oxo alpha,omega-Di-[N-(9-(9-phenylfluorenyl))amino]azelate Esters.

PubMed

Polyak, Felix; Lubell, William D.

1998-08-21

Azabicyclo[X.Y.0]alkane amino acids are tools for constructing mimics of peptide structure and templates for generating combinatorial libraries for drug discovery. Our methodology for synthesizing these conformationally rigid dipeptides has been elaborated such that alkyl groups can be appended onto the heterocycle to generate mimics of peptide backbone and side-chain structure. Inexpensive glutamic acid was employed as chiral educt in a Claisen condensation/ketone alkylation/reductive amination/lactam cyclization sequence that furnished alkyl-branched azabicyclo[4.3.0]alkane amino acid. Enantiopure 5-benzyl-, 7-benzyl-, and 5,7-dibenzylindolizidinone amino acids 2-4 were stereoselectively synthesized via efficient reaction sequences featuring the alkylation of di-tert-butyl alpha,omega-di-[N-(PhF)amino]azelate delta-ketone 5. A variety of alkyl halides were readily added to the enolate of ketone 5 to provide mono- and dialkylated ketones 6 and 7. Hydride additions to 6 and 7, methanesulfonations, and intramolecular S(N)2 displacements by the PhF amine gave 5-alkylprolines that were converted by lactam cyclizations into 7- and 5-benzyl-, as well as 5,7-dibenzyl-2-oxo-3-N-(BOC)amino-1-azabicyclo[4.3.0]nonane-9-carboxylate methyl esters 10, 11, and 14. Epimerization of the alkyl-branched stereocenter via an iminium-enaminium equilibrium proved effective for controlling diastereoselectivity in reductive aminations with 6 and 7 in order to furnish 5-alkylprolines that were similarly converted to 7- benzyl- and 5,7-dibenzylindolizidinone N-(BOC)amino esters 10 and 14. Ester hydrolysis with hydroxide ion and potassium trimethylsilanolate then gave enantiopure indolizidinone amino acids 2-4. Epimerization at C-9 of benzylindolizidinone amino esters was also used to provide alternative diastereomers of 10, 11, and 14. This practical methodology for introducing side-chain groups onto the heterocycle with regioselective and diastereoselective control is designed to enhance the use of alkyl-branched azabicycloalkane amino acids for the exploration of conformation-activity relationships of various biologically active peptides.
Characterization and evaluation of an oral microemulsion containing the antitumor diterpenoid compound ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid

PubMed Central

Lu, Yingnian; Wu, Kefeng; Li, Li; He, Yuhui; Cui, Liao; Liang, Nianci; Mu, Bozhong

2013-01-01

The objective of this study was to develop an oral microemulsion formulation of the antitumor diterpenoid agent, ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (henceforth referred to as 5F), to enhance its bioavailability and evaluate its hepatotoxicity. Pseudoternary phase diagrams showed that the optimal microemulsion formulation contained 45% water, 10% castor oil as the oil phase, 15% Cremophor EL as the surfactant, and 30% as a cosurfactant mixture of 1,2-propanediol and polyethylene glycol (PEG)-400 (2:1, w/w). The microemulsion preparation was characterized and its droplet diameter was within 50 nm. Release of 5F in vitro from the microemulsion was slightly increased compared with a suspension containing the same amount of active drug. Pharmacokinetic parameters in vivo indicated that bioavailability was markedly improved, with the relative bioavailability being 616.15% higher for the microemulsion than for the suspension. Toxicity tests showed that the microemulsion had no hepatotoxicity in mice. These results suggest the potential for 5F microemulsion to be administered by the oral route. PMID:23690685
Determination of 13-cis-retinoic acid and its major metabolite, 4-oxo-13-cis-retinoic acid, in human blood by reversed-phase high-performance liquid chromatography.

PubMed

Vane, F M; Stoltenborg, J K; Buggé, C J

1982-02-12

A high-performance liquid chromatography (HPLC) method for the quantitation of 13-cis-retinoic acid (13-cis-RA) and its major metabolite, 4-oxo-13-cis-RA, in human blood has been developed. The method includes extraction of 1 ml of blood with diethyl ether at pH 6 and the analysis of the extract by reversed-phase HPLC with solvent programming and detection at 365 nm. The quantitation ranges for 13-cis-RA and 4-oxo-13-cis-RA are 10--2000 and 50--2000 ng/ml of blood, respectively. The method also provides estimates of the concentrations of all-trans-RA and 4-oxo-all-trans-RA. The mean intra- and inter-assay variabilities for all four compounds were 6% or less. The method separates 13-cis-RA and 4-oxo-13-cis-RA from 9-cis-RA, all-trans-RA, 4-oxo-all-trans-RA, and some other possible metabolites, such as hydroxy and epoxy retinoic acids. The method has been successfully applied to the analyses of over 1200 blood samples from four 13-cis-RA clinical studies.
The noradrenaline precursor L-threo-3,4-dihydroxyphenylserine exhibits antinociceptive activity via central alpha-adrenoceptors in the mouse.

PubMed Central

Kawabata, A.; Kasamatsu, K.; Umeda, N.; Takagi, H.

1994-01-01

1. Systemic (s.c. or p.o.) administration of L-threo-3,4-dihydroxyphenylserine (droxidopa, L-threo-DOPS; L-DOPS), a noradrenaline precursor, at a dose-range of 100-800 mg kg-1, produced naloxone-resistant antinociception in a dose-dependent manner in the mouse, as assessed by the tail flick test, kaolin-induced writhing test and formalin-induced nociception test. 2. Antinociception elicited by L-DOPS (400 mg kg-1, s.c.) was not affected by s.c. injection of benserazide, a peripherally preferential L-aromatic amino acid decarboxylase inhibitor, but was suppressed by its intracerebroventricular (i.c.v.) injection. 3. I.c.v. or intrathecal (i.t.) administration of the non-selective alpha-blocker, phentolamine, significantly reduced L-DOPS-induced antinociception. 4. I.c.v. administration of the alpha 1-blocker, prazosin, but not the alpha 2-blocker, yohimbine, abolished the antinociceptive effects of L-DOPS. In contrast, both blockers, when administered i.t., exhibited significant inhibitory effects. 5. These results suggest that systemic L-DOPS produces opioid-independent antinociception, mediated by supraspinal alpha 1-adrenoceptors and by spinal alpha 1- and alpha 2-adrenoceptors and may predict additional therapeutic applications of L-DOPS as an analgesic. PMID:7911717
Cloning and sequence analysis of the meso-diaminopimelate decarboxylase gene from Bacillus methanolicus MGA3 and comparison to other decarboxylase genes.

PubMed Central

Mills, D A; Flickinger, M C

1993-01-01

The lysA gene of Bacillus methanolicus MGA3 was cloned by complementation of an auxotrophic Escherichia coli lysA22 mutant with a genomic library of B. methanolicus MGA3 chromosomal DNA. Subcloning localized the B. methanolicus MGA3 lysA gene into a 2.3-kb SmaI-SstI fragment. Sequence analysis of the 2.3-kb fragment indicated an open reading frame encoding a protein of 48,223 Da, which was similar to the meso-diaminopimelate (DAP) decarboxylase amino acid sequences of Bacillus subtilis (62%) and Corynebacterium glutamicum (40%). Amino acid sequence analysis indicated several regions of conservation among bacterial DAP decarboxylases, eukaryotic ornithine decarboxylases, and arginine decarboxylases, suggesting a common structural arrangement for positioning of substrate and the cofactor pyridoxal 5'-phosphate. The B. methanolicus MGA3 DAP decarboxylase was shown to be a dimer (M(r) 86,000) with a subunit molecular mass of approximately 50,000 Da. This decarboxylase is inhibited by lysine (Ki = 0.93 mM) with a Km of 0.8 mM for DAP. The inhibition pattern suggests that the activity of this enzyme in lysine-overproducing strains of B. methanolicus MGA3 may limit lysine synthesis. Images PMID:8215365

Cloning and sequence analysis of the meso-diaminopimelate decarboxylase gene from Bacillus methanolicus MGA3 and comparison to other decarboxylase genes.

PubMed

Mills, D A; Flickinger, M C

1993-09-01

The lysA gene of Bacillus methanolicus MGA3 was cloned by complementation of an auxotrophic Escherichia coli lysA22 mutant with a genomic library of B. methanolicus MGA3 chromosomal DNA. Subcloning localized the B. methanolicus MGA3 lysA gene into a 2.3-kb SmaI-SstI fragment. Sequence analysis of the 2.3-kb fragment indicated an open reading frame encoding a protein of 48,223 Da, which was similar to the meso-diaminopimelate (DAP) decarboxylase amino acid sequences of Bacillus subtilis (62%) and Corynebacterium glutamicum (40%). Amino acid sequence analysis indicated several regions of conservation among bacterial DAP decarboxylases, eukaryotic ornithine decarboxylases, and arginine decarboxylases, suggesting a common structural arrangement for positioning of substrate and the cofactor pyridoxal 5'-phosphate. The B. methanolicus MGA3 DAP decarboxylase was shown to be a dimer (M(r) 86,000) with a subunit molecular mass of approximately 50,000 Da. This decarboxylase is inhibited by lysine (Ki = 0.93 mM) with a Km of 0.8 mM for DAP. The inhibition pattern suggests that the activity of this enzyme in lysine-overproducing strains of B. methanolicus MGA3 may limit lysine synthesis.
A maize death acid, 10-oxo-11-phytoenoic acid, is the predominant cyclopentenone signal present during multiple stress and developmental conditions

PubMed Central

Christensen, Shawn A.; Huffaker, Alisa; Hunter, Charles T.; Alborn, Hans T.; Schmelz, Eric A.

2016-01-01

abstract Recently we investigated the function of the 9-lipoxygenase (LOX) derived cyclopentenones 10-oxo-11-phytoenoic acid (10-OPEA) and 10-oxo-11,15-phytodienoic acid (10-OPDA) and identified their C-14 and C-12 derivatives. 10-OPEA accumulation is elicited by fungal and insect attack and acts as a strong inhibitor of microbial and herbivore growth. Although structurally similar, comparative analyses between 10-OPEA and its 13-LOX analog 12-oxo-phytodienoic acid (12-OPDA) demonstrate specificity in transcript accumulation linked to detoxification, secondary metabolism, jasmonate regulation, and protease inhibition. As a potent cell death signal, 10-OPEA activates cysteine protease activity leading to ion leakage and apoptotic-like DNA fragmentation. In this study we further elucidate the distribution, abundance, and functional roles of 10-OPEA, 10-OPDA, and 12-OPDA, in diverse organs under pathogen- and insect-related stress. PMID:26669723
Vector-mediated chromosomal integration of the glutamate decarboxylase gene in streptococcus thermophilus

USDA-ARS?s Scientific Manuscript database

The integrative vector pINTRS was used to transfer glutamate decarboxylase (GAD) activity to Streptococcus thermophilus ST128, thus allowing for the production of '-aminobutyric acid (GABA). In pINTRS, the gene encoding glutamate decarboxylase, gadB, was flanked by DNA fragments homologous to a S. ...
Maple syrup urine disease: The E1{beta} gene of human branched-chain {alpha}-ketoacid dehydrogenase complex has 11 rather than 10 exons, and the 3{prime} UTR in one of the two E1{beta} mRNAs arises from intronic sequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chuang, J.L.; Chuang, D.T.; Cox, R.P.

1996-06-01

Maple syrup urine disease (MSUD) or branched-chain ketoaciduria is caused by a deficiency in the mitochondrial branched-chain {alpha}-ketoacid dehydrogenase (BCKAD) complex. The clinical manifestations are characterized by accumulation of branched chain amino and {alpha}-ketoacids, which leads to severe cerebral edema with seizures, ketoacidosis, and mental retardation. The BCKAD complex comprises three catalytic components, i.e., a decarboxylase (E1) consisting of two E1{alpha} (M{sub r} = 46,000) and two E1{Beta} (M{sub r} = 37,500) subunits, a transacylase (E2) that contains 24 lipoic acid-bearing subunits, and a dehydrogenase (E3), which is a homodimeric flavoprotein. MSUD is genetically heterogeneous, since mutations in the E1{alpha}more » subunit (type IA MSUD), the E1{Beta} subunit (type IB), the E2 subunit (type II) and the E3 subunit (type III) have been described. The functional consequences of certain mutations in the BCKAD complex have been studied. 23 refs., 3 figs.« less
The maize death acids, 10-oxo-11-phytoenoic acid and derivatives, demonstrate specificity in jasmonate-related signaling and defense

USDA-ARS?s Scientific Manuscript database

Plant cellular damage promotes the interaction of lipoxygenases (LOX) with free fatty acids to yield 9- and 13-hydroperoxides which are further metabolized into diverse oxylipins. The enzymatic action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downst...
The physiological disposition of the uricosuric-saluretic agent (6,7-dichloro-2-methyl-1-oxo-2-phenyl-5-indanyloxy)acetic acid (MK-196) in the rat, dog, and monkey.

PubMed

Zacchei, A G; Wishousky, T I

1976-01-01

The physiological disposition of a new saluretic-uricosuric agent, (6,7-dichloro-2-methyl-1-oxo-2-phenyl-5-indanyloxy)acetic acid (MK-196), was studied in the rat, dog, and monkey. MK-196 was well absorbed and showed minimal metabolism in these species. Peak plasma levels of radioactivity and drug occurred 0.5-2 hr after oral administration at a dose of 2.5 mg/kg. Essentially all of the radioactivity present in the plasma during the first day was intact MK-196. Following a single dose, a long terminal half-life for plasma radioactivity was observed in the dog (approximately 68 hr) and monkey (approximately 105 hr). The chronic administration of MK-196 to dogs resulted in a dose-related plasma profile and showed no tendency to increase or decrease with dosing. However, upon repeated drug administration to monkeys, the plasma levels of drug increased and then decreased, possibly due to hypochloremia and secondary metabolic alkalosis. Fecal excretion was the predominant route of tracer elimination in the dog (approximately 80%) and rat (approximately 94%), whereas the monkey eliminated the majority of the dose (approximately 60%) via the urine. Minimal metabolism was noted in the three lower species; most of the urinary, plasma, and fecal radioactivity was accounted for as intact drug and its glucuronide conjugate. Three minor metabolites, which were present in dog bile, plasma, and urine, were characterized as: (l,7-dichloro-1alpha-hydroxy-2-methyl-2-phenyl-5-indanyloxy)acetic acid, I; (6,7-dichloro-2-(4-hydroxyphenyl)-2-methyl-2-oxo-5-indanyloxy)acetic acid, II; and 2-methyl-2-phenyl-5-hydroxy-6,7-dichloro-1-indanone, III. The monkey urine and plasma also contained small amounts of II.
Requirement of a Functional Flavin Mononucleotide Prenyltransferase for the Activity of a Bacterial Decarboxylase in a Heterologous Muconic Acid Pathway in Saccharomyces cerevisiae.

PubMed

Weber, Heike E; Gottardi, Manuela; Brückner, Christine; Oreb, Mislav; Boles, Eckhard; Tripp, Joanna

2017-05-15

Biotechnological production of cis , cis -muconic acid from renewable feedstocks is an environmentally sustainable alternative to conventional, petroleum-based methods. Even though a heterologous production pathway for cis , cis -muconic acid has already been established in the host organism Saccharomyces cerevisiae , the generation of industrially relevant amounts of cis , cis -muconic acid is hampered by the low activity of the bacterial protocatechuic acid (PCA) decarboxylase AroY isomeric subunit C iso (AroY-C iso ), leading to secretion of large amounts of the intermediate PCA into the medium. In the present study, we show that the activity of AroY-C iso in S. cerevisiae strongly depends on the strain background. We could demonstrate that the strain dependency is caused by the presence or absence of an intact genomic copy of PAD1 , which encodes a mitochondrial enzyme responsible for the biosynthesis of a prenylated form of the cofactor flavin mononucleotide (prFMN). The inactivity of AroY-C iso in strain CEN.PK2-1 could be overcome by plasmid-borne expression of Pad1 or its bacterial homologue AroY subunit B (AroY-B). Our data reveal that the two enzymes perform the same function in decarboxylation of PCA by AroY-C iso , although coexpression of Pad1 led to higher decarboxylase activity. Conversely, AroY-B can replace Pad1 in its function in decarboxylation of phenylacrylic acids by ferulic acid decarboxylase Fdc1. Targeting of the majority of AroY-B to mitochondria by fusion to a heterologous mitochondrial targeting signal did not improve decarboxylase activity of AroY-C iso , suggesting that mitochondrial localization has no major impact on cofactor biosynthesis. IMPORTANCE In Saccharomyces cerevisiae , the decarboxylation of protocatechuic acid (PCA) to catechol is the bottleneck reaction in the heterologous biosynthetic pathway for production of cis , cis -muconic acid, a valuable precursor for the production of bulk chemicals. In our work, we demonstrate the importance of the strain background for the activity of a bacterial PCA decarboxylase in S. cerevisiae Inactivity of the decarboxylase is due to a nonsense mutation in a gene encoding a mitochondrial enzyme involved in the biosynthesis of a cofactor required for decarboxylase function. Our study reveals functional interchangeability of Pad1 and a bacterial homologue, irrespective of their intracellular localization. Our results open up new possibilities to improve muconic acid production by engineering cofactor supply. Furthermore, the results have important implications for the choice of the production strain. Copyright © 2017 American Society for Microbiology.
Trypanosoma cruzi has not lost its S-adenosylmethionine decarboxylase: characterization of the gene and the encoded enzyme.

PubMed Central

Persson, K; Aslund, L; Grahn, B; Hanke, J; Heby, O

1998-01-01

All attempts to identify ornithine decarboxylase in the human pathogen Trypanosoma cruzi have failed. The parasites have instead been assumed to depend on putrescine uptake and S-adenosylmethionine decarboxylase (AdoMetDC) for their synthesis of the polyamines spermidine and spermine. We have now identified the gene encoding AdoMetDC in T. cruzi by PCR cloning, with degenerate primers corresponding to conserved amino acid sequences in AdoMetDC proteins of other trypanosomatids. The amplified DNA fragment was used as a probe to isolate the complete AdoMetDC gene from a T. cruzi genomic library. The AdoMetDC gene was located on chromosomes with a size of approx. 1.4 Mbp, and contained a coding region of 1110 bp, specifying a sequence of 370 amino acid residues. The protein showed a sequence identity of only 25% with human AdoMetDC, the major differences being additional amino acids present in the terminal regions of the T. cruzi enzyme. As expected, a higher sequence identity (68-72%) was found in comparison with trypanosomatid AdoMetDCs. When the coding region was expressed in Escherichia coli, the recombinant protein underwent autocatalytic cleavage, generating a 33-34 kDa alpha subunit and a 9 kDa beta subunit. The encoded protein catalysed the decarboxylation of AdoMet (Km 0.21 mM) and was stimulated by putrescine but inhibited by the polyamines, weakly by spermidine and strongly by spermine. Methylglyoxal-bis(guanylhydrazone) (MGBG), a potent inhibitor of human AdoMetDC, was a poor inhibitor of the T. cruzi enzyme. This differential sensitivity to MGBG suggests that the two enzymes are sufficiently different to warrant the search for compounds that might interfere with the progression of Chagas' disease by selectively inhibiting T. cruzi AdoMetDC. PMID:9677309
Ursane-type nortriterpenes with a five-membered A-ring from Rubus innominatus.

PubMed

Chen, Zhenzhong; Tong, Ling; Feng, Yuanli; Wu, Jizhou; Zhao, Xiaoya; Ruan, Hanli; Pi, Huifang; Zhang, Peng

2015-08-01

Two nortriterpenes (rubuminatus A and B), which contain a distinctive contracted a five-membered A-ring ursane-type skeleton, and six triterpenes along with 17 known triterpenes were isolated from the roots of Rubus innominatus S. Moore. These structures were determined to be 19α-hydroxy-2-oxo-nor- A(3)-urs-12-en-28-oic acid, 1β,19α-dihydroxy-2-oxo-nor-A(3)-urs-12-en-28-oic acid, 1β,2α,3α,19α-tetrahy droxyurs-12-en-23-formyl-28-oic acid, 1β,2α,3α,19α,23- pentahydroxyurs-11-en-28-oic acid, 1-oxo-siaresinolic acid, 2α,3α-dihydroxyolean-11,13(18)-dien-19β,28-olide, 1β,2α,3α-trihydroxy-19-oxo- 18,19-seco-urs-11,13(18)-dien-28-oic acid, and 2-O-benzoyl alphitolic acid based on extensive spectroscopic analyses. In vitro anti-inflammatory abilities to modulate the production of TNF-α, IL-1β, and IL-6 in LPS-induced RAW 264.7 macrophages of the compounds were determined. Rubuminatus A and B, as well as 1-oxo-siaresinolic acid and 2α,3α-dihydroxyolean-11,13(18)-dien-19β,28-olide, exhibited significant inhibitory effects on these cytokines. Copyright © 2015 Elsevier Ltd. All rights reserved.
Molecular and functional analyses of amino acid decarboxylases involved in cuticle tanning in Tribolium castaneum

USDA-ARS?s Scientific Manuscript database

Aspartate 1-decarboxylase (ADC) and dopa decarboxylase (DDC) provide b–alanine and dopamine used in insect cuticle tanning. Beta-alanine is conjugated with dopamine to yield N-b-alanyldopamine (NBAD), a substrate for the phenoloxidase laccase that catalyzes the synthesis of cuticle protein cross-li...
The mitochondrial pyruvate carrier. Kinetics and specificity for substrates and inhibitors.

PubMed

Halestrap, A P

1975-04-01

1. Studies on the kinetics of pyruvate transport into mitochondria by an 'inhibitor-stop' technique were hampered by the decarboxylation of pyruvate by mitochondria even in the presence of rotenone. Decarboxylation was minimal at 6 degrees C. At this temperature the Km for pyruvate was 0.15 mM and Vmax. was 0.54nmol/min per mg of protein; alpha-cyano-4-hydroxycinnamate was found to be a non-competitive inhibitor, Ki 6.3 muM, and phenyl-pyruvate a competitive inhibitor, Ki 1.8 mM. 2. At 100 muM concentration, alpha-cyano-4-hydroxycinnamate rapidly and almost totally inhibited O2 uptake by rat heart mitochondria oxidizing pyruvate. Inhibition could be detected at concentrations of inhibitor as low as 1 muM although inhibition took time to develop at this concentration. Inhibition could be reversed by diluting out the inhibitor. 3. Various analogues of alpha-cyano-4-hydroxycinnamate were tested on rat liver and heart mitochondria. The important structural features appeared to be the alpha-cyanopropenoate group and the hydrophobic aromatic side chain. Alpha-Cyanocinnamate, alpha-cyano-5-phenyl-2,4-pentadienoate and compound UK 5099 [alpha-cyano-beta-(2-phenylindol-3-yl)acrylate] were all more powerful inhibitors than alpha-cyano-4-hydroxycinnamate showing 50% inhibition of pyruvate-dependent O2 consumption by rat heart mitochondria at concentrations of 200, 200 and 50 nM respectively. 4. The specificity of the carrier for its substrate was studied by both influx and efflux experiments. Oxamate, 2-oxobutyrate, phenylpyruvate, 2-oxo-4-methyl-pentanoate, chloroacetate, dichloroacetate, difluoroacetate, 2-chloropropionate, 3-chloropropionate and 2,2-dichloropropionate all exchanged with pyruvate, whereas acetate, lactate and trichloroacetate did not. 5. Pyruvate entry into the mitochondria was shown to be accompanied by the transport of a proton (or by exchange with an OH-ion). This proton flux was inhibited by alpha-cyano-4-hydroxycinnamate and allowed measurements of pyruvate transport at higher temperatures to be made. The activation energy of mitochondrial pyruvate transport was found to be 113 kJ (27 kcal)/mol and by extrapolation the rate of transport of pyruvate at 37 degrees C to be 42 nmol/min per mg of protein. The possibility that pyruvate transport into mitochondria may be rate limiting and involved in the regulation of gluconegenesis is discussed. 6. The transport of various monocarboxylic acids into mitochondria was studied by monitoring proton influx. The transport of dichloroacetate, difluoroacetate and oxamate appeared to be largely dependent on the pyruvate carrier and could be inhibited by pyruvate-transport inhibitors. However, many other halogenated and 2-oxo acids which could exchange with pyruvate on the carrier entered freely even in the presence of inhibitor.
16-Cyclopentadienyl tricarbonyl 99mTc 16-oxo-hexadecanoic acid: synthesis and evaluation of fatty acid metabolism in mouse myocardium.

PubMed

Lee, Byung Chul; Kim, Dong Hyun; Lee, Iljung; Choe, Yearn Seong; Chi, Dae Yoon; Lee, Kyung-Han; Choi, Yong; Kim, Byung-Tae

2008-06-26

We synthesized 16-cyclopentadienyl tricarbonyl 99mTc 16-oxo-hexadecanoic acid (99mTc-CpTT-16-oxo-HDA, 1) and investigated its potential as a radiotracer for evaluating fatty acid metabolism in myocardium. Radiotracer 1 was synthesized in 22.6 +/- 6.3% decay-corrected yield by a double ligand transfer reaction between the ferrocene adduct of methyl hexadecanoate ( 2) and Na99mTcO 4 in the presence of Cr(CO)6 and CrCl3, followed by hydrolysis of the methyl ester group. Radiotracer 1 was found to be chemically stable (99% at 6 h) when incubated in human serum. A tissue distribution study in mice showed that high radioactivity accumulated in heart (9.03%ID/g at 1 min and 5.41%ID/g at 5 min postinjection) with rapid clearance and that heart to blood uptake ratios increased with time (2.13 at 5 min and 3.76 at 30 min postinjection). Metabolite analysis of the heart tissues using a simple extraction method showed that 99mTc-CpTT-4-oxo-butyric acid was detected as the major radioactive metabolite by HPLC, suggesting that 1 is metabolized to 99mTc-CpTT-4-oxo-butyric acid via beta-oxidation in myocardium.
Protection of wheat against leaf and stem rust and powdery mildew diseases by inhibition of polyamine metabolism

NASA Technical Reports Server (NTRS)

Weinstein, L. H.; Osmeloski, J. F.; Wettlaufer, S. H.; Galston, A. W.

1987-01-01

In higher plants, polyamines arise from arginine by one of two pathways: via ornithine and ornithine decarboxylase or via agmatine and arginine decarboxylase but in fungi, only the ornithine decarboxylase pathway is present. Since polyamines are required for normal growth of microorganisms and plants and since the ornithine pathway can be irreversibly blocked by alpha-difluoromethylornithine (DFMO) which has no effect on arginine decarboxylase, fungal infection of green plants might be controlled by the site-directed use of such a specific metabolic inhibitor. DFMO at relatively low concentrations provided effective control of the three biotrophic fungal pathogens studied, Puccinia recondita (leaf rust), P. graminis f. sp. tritici (stem rust), and Erysiphe graminis (powdery mildew) on wheat (Triticum aestivum L.) Effective control of infection by leaf or stem rust fungi was obtained with sprays of DFMO that ranged from about 0.01 to 0.20 mM in experiments where the inhibitor was applied after spore inoculation. The powdery mildew fungus was somewhat more tolerant of DFMO, but good control of the pathogen was obtained at less than 1.0 mM. In general, application of DFMO after spore inoculation was more effective than application before inoculation. Less control was obtained following treatment with alpha-difluoromethylarginine (DFMA) but the relatively high degree of control obtained raises the possibility of a DFMA to DFMO conversion by arginase.
Identification, Cloning, and Characterization of a Lactococcus lactis Branched-Chain α-Keto Acid Decarboxylase Involved in Flavor Formation

PubMed Central

Smit, Bart A.; van Hylckama Vlieg, Johan E. T.; Engels, Wim J. M.; Meijer, Laura; Wouters, Jan T. M.; Smit, Gerrit

2005-01-01

The biochemical pathway for formation of branched-chain aldehydes, which are important flavor compounds derived from proteins in fermented dairy products, consists of a protease, peptidases, a transaminase, and a branched-chain α-keto acid decarboxylase (KdcA). The activity of the latter enzyme has been found only in a limited number of Lactococcus lactis strains. By using a random mutagenesis approach, the gene encoding KdcA in L. lactis B1157 was identified. The gene for this enzyme is highly homologous to the gene annotated ipd, which encodes a putative indole pyruvate decarboxylase, in L. lactis IL1403. Strain IL1403 does not produce KdcA, which could be explained by a 270-nucleotide deletion at the 3′ terminus of the ipd gene encoding a truncated nonfunctional decarboxylase. The kdcA gene was overexpressed in L. lactis for further characterization of the decarboxylase enzyme. Of all of the potential substrates tested, the highest activity was observed with branched-chain α-keto acids. Moreover, the enzyme activity was hardly affected by high salinity, and optimal activity was found at pH 6.3, indicating that the enzyme might be active under cheese ripening conditions. PMID:15640202
C acid decarboxylases required for C photosynthesis are active in the mid-vein of the C species Arabidopsis thaliana, and are important in sugar and amino acid metabolism.

PubMed

Brown, Naomi J; Palmer, Ben G; Stanley, Susan; Hajaji, Hana; Janacek, Sophie H; Astley, Holly M; Parsley, Kate; Kajala, Kaisa; Quick, W Paul; Trenkamp, Sandra; Fernie, Alisdair R; Maurino, Veronica G; Hibberd, Julian M

2010-01-01

Cells associated with veins of petioles of C(3) tobacco possess high activities of the decarboxylase enzymes required in C(4) photosynthesis. It is not clear whether this is the case in other C(3) species, nor whether these enzymes provide precursors for specific biosynthetic pathways. Here, we investigate the activity of C(4) acid decarboxylases in the mid-vein of Arabidopsis, identify regulatory regions sufficient for this activity, and determine the impact of removing individual isoforms of each protein on mid-vein metabolite profiles. This showed that radiolabelled malate and bicarbonate fed to the xylem stream were incorporated into soluble and insoluble material in the mid-vein of Arabidopsis leaves. Compared with the leaf lamina, mid-veins possessed high activities of NADP-dependent malic enzyme (NADP-ME), NAD-dependent malic enzyme (NAD-ME) and phosphoenolpyruvate carboxykinase (PEPCK). Transcripts derived from both NAD-ME, one PCK and two of the four NADP-ME genes were detectable in these veinal cells. The promoters of each decarboxylase gene were sufficient for expression in mid-veins. Analysis of insertional mutants revealed that cytosolic NADP-ME2 is responsible for 80% of NADP-ME activity in mid-veins. Removing individual decarboxylases affected the abundance of amino acids derived from pyruvate and phosphoenolpyruvate. Reducing cytosolic NADP-ME activity preferentially affected the sugar content, whereas abolishing NAD-ME affected both the amino acid and the glucosamine content of mid-veins.
40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...
40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...
40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...
40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...
40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4... established for residues of the herbicide flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5-[5-methyl-6-oxo-4...

Agdc1p – a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans

PubMed Central

Meier, Anna K.; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

2017-01-01

Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (Km −0.7 ± 0.2 mM, kcat −42.0 ± 8.2 s−1) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (Km −3.2 ± 0.2 mM, kcat −44.0 ± 3.2 s−1). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δagdc1] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis-muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be not the only degradation pathway. PMID:28966611
Agdc1p - a Gallic Acid Decarboxylase Involved in the Degradation of Tannic Acid in the Yeast Blastobotrys (Arxula) adeninivorans.

PubMed

Meier, Anna K; Worch, Sebastian; Böer, Erik; Hartmann, Anja; Mascher, Martin; Marzec, Marek; Scholz, Uwe; Riechen, Jan; Baronian, Kim; Schauer, Frieder; Bode, Rüdiger; Kunze, Gotthard

2017-01-01

Tannins and hydroxylated aromatic acids, such as gallic acid (3,4,5-trihydroxybenzoic acid), are plant secondary metabolites which protect plants against herbivores and plant-associated microorganisms. Some microbes, such as the yeast Arxula adeninivorans are resistant to these antimicrobial substances and are able to use tannins and gallic acid as carbon sources. In this study, the Arxula gallic acid decarboxylase (Agdc1p) which degrades gallic acid to pyrogallol was characterized and its function in tannin catabolism analyzed. The enzyme has a higher affinity for gallic acid (K m -0.7 ± 0.2 mM, k cat -42.0 ± 8.2 s -1 ) than to protocatechuic acid (3,4-dihydroxybenzoic acid) (K m -3.2 ± 0.2 mM, k cat -44.0 ± 3.2 s -1 ). Other hydroxylated aromatic acids, such as 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid are not gallic acid decarboxylase substrates. A. adeninivorans G1212/YRC102-AYNI1-AGDC1, which expresses the AGDC1 gene under the control of the strong nitrate inducible AYNI1 promoter achieved a maximum gallic acid decarboxylase activity of 1064.4 U/l and 97.5 U/g of dry cell weight in yeast grown in minimal medium with nitrate as nitrogen source and glucose as carbon source. In the same medium, gallic acid decarboxylase activity was not detected for the control strain G1212/YRC102 with AGDC1 expression under the control of the endogenous promoter. Gene expression analysis showed that AGDC1 is induced by gallic acid and protocatechuic acid. In contrast to G1212/YRC102-AYNI1-AGDC1 and G1212/YRC102, A. adeninivorans G1234 [Δ agdc1 ] is not able to grow on medium with gallic acid as carbon source but can grow in presence of protocatechuic acid. This confirms that Agdc1p plays an essential role in the tannic acid catabolism and could be useful in the production of catechol and cis,cis -muconic acid. However, the protocatechuic acid catabolism via Agdc1p to catechol seems to be not the only degradation pathway.
Metabolism of 13-cis-retinoic acid by a rat liver 9000g supernatant preparation.

PubMed

Vane, F M; Buggé, C J; Williams, T H

1982-01-01

The in vitro metabolites formed on incubation of 13-cis-retinoic acid (13-cis-RA, isotretinoin) with a 9000g rat liver supernatant system were isolated by HPLC and identified by their mass and NMR spectra. The major metabolic pathway was hydroxylation at C4 to give 4-hydroxy-13-cis-RA, which was rapidly oxidized to 4-oxo-13-cis-RA, the major isolated metabolite. Further metabolism of this 4-oxo metabolite led to two novel compounds, 2-hydroxy-4-oxo-13-cis-RA and 3-hydroxy-4-oxo-13-cis-RA. In addition, small amounts of 13-cis-RA and 4-oxo-13-cis-RA were enzymatically converted to their all-trans isomers. Support for these pathways was obtained by the metabolism of reference samples of 4-hydroxy-13-cis-RA, 4-oxo-13-cis-RA, all-trans-RA, and 4-oxo-all-trans-RA. The predominant formation of 4-oxo metabolites of 13-cis-RA in this in vitro rat system and the results from previously reported in vivo metabolism studies suggest that oxidation at C4 is a major metabolic pathway of 13-cis-RA in both rats and humans.
Developmental outcome of levetiracetam, its major metabolite in humans, 2-pyrrolidinone N-butyric acid, and its enantiomer (R)-alpha-ethyl-oxo-pyrrolidine acetamide in a mouse model of teratogenicity.

PubMed

Isoherranen, Nina; Spiegelstein, Ofer; Bialer, Meir; Zhang, Jing; Merriweather, Michelle; Yagen, Boris; Roeder, Michael; Triplett, Aleata A; Schurig, Volker; Finnell, Richard H

2003-10-01

The purpose of this study was to test the teratogenic potential of the antiepileptic drug (AED) levetiracetam (LEV), its major metabolite in humans, 2-pyrrolidone-N-butyric acid (PBA), and enantiomer, (R)-alpha-ethyl-oxo-pyrrolidine acetamide (REV), in a well-established mouse model. All compounds were administered by intraperitoneal injections once daily to SWV/Fnn mice on gestational days 8-1/2 to 12-1/2. LEV was administered at doses of 600, 1,200, and 2,000 mg/kg/day, piracetam (PIR) and PBA, at 600 and 1,200 mg/kg/day, and REV, at 600 mg/kg/day. On gestational day 18(1/2), fetuses were examined for gross external malformations and prepared for skeletal analysis by using Alizarin Red S staining. No significant gross external malformations were observed in any of the study groups. Fetal weights were significantly reduced in most study groups. Resorption rates were significantly increased only in the 2,000-mg/kg/day LEV group. The overall incidence of skeletal abnormalities and specifically of hypoplastic phalanges was significantly increased in both PBA treatments and in the intermediate 1,200-mg/kg/day LEV group. In contrast to that in humans, 24-h urinary excretion analysis in mice showed that 65-100% of the LEV doses were excreted unchanged, whereas only 4% was excreted as the metabolite PBA. Results of this study demonstrate that both LEV and its major metabolite in humans, PBA, do not induce major structural malformations in developing SWV/Fnn embryos and suggest that they provide a margin of reproductive safety for the pregnant epileptic population when compared with other AEDs tested in this mouse model.
76 FR 39358 - Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or on Various...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-06

... 0.15 ppm; and crop group 18 non-grass animal feed (forage, fodder, straw, and hay): Alfalfa, forage...-ethyl (ethyl- alpha-2-dichloro-5-[-4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1 H -1,2,4-triazol-1-yl...-dichloro-5-[-4- difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1 H -1,2,4-triazol-1-yl]-4...
Evaluation of the use of malic acid decarboxylase-deficient starter culture in NaCl-free cucumber fermentations to reduce bloater incidence

USDA-ARS?s Scientific Manuscript database

AIMS: Accumulation of carbon dioxide in cucumber fermentations is known to cause hollow cavities inside whole fruits or bloaters, conducive to economic losses for the pickling industry. This study focused on evaluating the use of a malic acid decarboxylase (MDC)-deficient starter culture to minimiz...
Involvement of the ornithine decarboxylase gene in acid stress response in probiotic Lactobacillus delbrueckii UFV H2b20.

PubMed

Ferreira, A B; Oliveira, M N V de; Freitas, F S; Paiva, A D; Alfenas-Zerbini, P; Silva, D F da; Queiroz, M V de; Borges, A C; Moraes, C A de

2015-01-01

Amino acid decarboxylation is important for the maintenance of intracellular pH under acid stress. This study aims to carry out phylogenetic and expression analysis by real-time PCR of two genes that encode proteins involved in ornithine decarboxylation in Lactobacillus delbrueckii UFV H2b20 exposed to acid stress. Sequencing and phylogeny analysis of genes encoding ornithine decarboxylase and amino acid permease in L. delbrueckii UFV H2b20 showed their high sequence identity (99%) and grouping with those of L. delbrueckii subsp. bulgaricus ATCC 11842. Exposure of L. delbrueckii UFV H2b20 cells in MRS pH 3.5 for 30 and 60 min caused a significant increase in expression of the gene encoding ornithine decarboxylase (up to 8.1 times higher when compared to the control treatment). Increased expression of the ornithine decarboxylase gene demonstrates its involvement in acid stress response in L. delbrueckii UFV H2b20, evidencing that the protein encoded by that gene could be involved in intracellular pH regulation. The results obtained show ornithine decarboxylation as a possible mechanism of adaptation to an acidic environmental condition, a desirable and necessary characteristic for probiotic cultures and certainly important to the survival and persistence of the L. delbrueckii UFV H2b20 in the human gastrointestinal tract.
Evidence of Two Functionally Distinct Ornithine Decarboxylation Systems in Lactic Acid Bacteria

PubMed Central

Romano, Andrea; Trip, Hein; Lonvaud-Funel, Aline; Lolkema, Juke S.

2012-01-01

Biogenic amines are low-molecular-weight organic bases whose presence in food can result in health problems. The biosynthesis of biogenic amines in fermented foods mostly proceeds through amino acid decarboxylation carried out by lactic acid bacteria (LAB), but not all systems leading to biogenic amine production by LAB have been thoroughly characterized. Here, putative ornithine decarboxylation pathways consisting of a putative ornithine decarboxylase and an amino acid transporter were identified in LAB by strain collection screening and database searches. The decarboxylases were produced in heterologous hosts and purified and characterized in vitro, whereas transporters were heterologously expressed in Lactococcus lactis and functionally characterized in vivo. Amino acid decarboxylation by whole cells of the original hosts was determined as well. We concluded that two distinct types of ornithine decarboxylation systems exist in LAB. One is composed of an ornithine decarboxylase coupled to an ornithine/putrescine transmembrane exchanger. Their combined activities results in the extracellular release of putrescine. This typical amino acid decarboxylation system is present in only a few LAB strains and may contribute to metabolic energy production and/or pH homeostasis. The second system is widespread among LAB. It is composed of a decarboxylase active on ornithine and l-2,4-diaminobutyric acid (DABA) and a transporter that mediates unidirectional transport of ornithine into the cytoplasm. Diamines that result from this second system are retained within the cytosol. PMID:22247134
Humanized in vivo Model for Autoimmune Diabetes

DTIC Science & Technology

2010-05-07

the tolerance mechanisms of high and low avidity T cells reactive to the diabetes autoantigen glutamic acid decarboxylase 65 (GAD65) and their...of this study, we have used humanized DR0401 (DR4) mice and demonstrated that: high avidity T cells reactive to glutamic acid decarboxylase 65...JA, Unrath KA, Falk BA, Ito K, Wen L, Daniels LT, Lernmark A, Nepom GT. Age-dependent loss of tolerance to an immunodominant epitope of glutamic acid
Biotransformation of nitroso aromatic compounds and 2-oxo acids to N-hydroxy-N-arylacylamides by thiamine-dependent enzymes in rat liver.

PubMed

Yoshioka, T; Uematsu, T

1998-07-01

The formation of N-hydroxy-N-arylacylamides from nitroso aromatic compounds and 2-oxo acids was investigated using rat liver subcellular fractions. Activities were found in both mitochondria and cytosol, except for activities for phenylpyruvate and glyoxylate; the former did not produce N-hydroxy-N-phenylphenylacetamide and the latter nonenzymatically produced N-hydroxy-N-phenylformamide with nitrosobenzene (NOB). The cytosolic activity of N-hydroxy-N-phenylglycolamide formation was indicated to be due to transketolase, which utilized hydroxypyruvate as a glycolic aldehyde donor to NOB. With mitochondria, 2-oxo acids (including hydroxypyruvate) served as substrates for the biotransformation of NOB to the corresponding N-hydroxy-N-phenylacylamides. The substrate preference was 2-oxobutyrate > pyruvate > 2-oxoisovalerate > 2-oxoisocaproate > 2-oxovalerate > 2-oxo-3-methylvalerate, judging from Vmax/half-saturating concentration for mitochondria values. The half-saturating concentrations for NOB were nearly constant. The mitochondrial activity was due to pyruvate dehydrogenase complex and branched-chain 2-oxo acid dehydrogenase complex (BCDHC). By using partially purified BCDHC, pyruvate and 2-oxobutyrate were found to be common substrates for both of the enzymes, and 2-oxoisovalerate was shown to be the most effective substrate for BCDHC. Analysis by the Taft equation indicated that the polar effects, rather than the steric effects, of the alkyl groups of 2-oxo acids are important for BCDHC-catalyzed formation of N-hydroxy-N-phenylacylamides. A positive Hammett constant obtained for the formation of N-hydroxy-N-arylisobutyramides indicates that an electron-withdrawing substituent makes the nitroso compounds susceptible to BCDHC-catalyzed biotransformation.
The catalytic activity for ginkgolic acid biodegradation, homology modeling and molecular dynamic simulation of salicylic acid decarboxylase.

PubMed

Hu, Yanying; Hua, Qingyuan; Sun, Guojuan; Shi, Kunpeng; Zhang, Huitu; Zhao, Kai; Jia, Shiru; Dai, Yujie; Wu, Qingli

2018-05-02

The toxic ginkgolic acids are the main safety concern for the application of Ginkgo biloba. In this study, the degradation ability of salicylic acid decarboxylase (SDC) for ginkgolic acids was examined using ginkgolic acid C15:1 as a substrate. The results indicated that the content of ginkgolic acid C15:1 in Ginkgo biloba seeds was significantly decreased after 5 h treatment with SDC at 40 °Cand pH 5.5. In order to explore the structure of SDC and the interaction between SDC and substrates, homology modeling, molecular docking and molecular dynamics were performed. The results showed that SDC might also have a catalytic active center containing a Zn 2+ . Compared with the template structure of 2,6-dihydroxybenzoate decarboxylase, the residues surrounding the binding pocket, His10, Phe23 and Phe290, were replaced by Ala10, Tyr27 and Tyr301 in the homology constructed structure of SDC, respectively. These differences may significantly affect the substrates adaptability of SDC for salicylic acid derivatives. Copyright © 2018 Elsevier Ltd. All rights reserved.
Red-excitation resonance Raman analysis of the nu(Fe=O) mode of ferryl-oxo hemoproteins.

PubMed

Ikemura, Kenichiro; Mukai, Masahiro; Shimada, Hideo; Tsukihara, Tomitake; Yamaguchi, Satoru; Shinzawa-Itoh, Kyoko; Yoshikawa, Shinya; Ogura, Takashi

2008-11-05

The Raman excitation profile of the nuFe O mode of horseradish peroxidase compound II exhibits a maximum at 580 nm. This maximum is located within an absorption band with a shoulder assignable to an oxygen-to-iron charge transfer band on the longer wavelength side of the alpha-band. Resonance Raman bands of the nuFe O mode of various ferryl-oxo type hemoproteins measured at 590 nm excitation indicate that many hemoproteins in the ferryl-oxo state have an oxygen-to-iron charge transfer band in the visible region. Since this red-excited resonance Raman technique causes much less photochemical damage in the proteins relative to blue-excited resonance Raman spectroscopy, it produces a higher signal-to-noise ratio and thus represents a powerful tool for investigations of ferryl-oxo intermediates of hemoproteins.
Characterization of a dual specificity aryl acid adenylation enzyme with dual function in nikkomycin biosynthesis.

PubMed

Moon, Mary; Van Lanen, Steven G

2010-09-01

Nikkomycin Z is a dipeptide antifungal antibiotic characterized by two nonproteinogenic amino acids, nikkomycin C(Z) and 4-(4'-hydroxy-2'-pyridinyl)-homothreonine (HPHT). The HPHT scaffold is assembled by an aldol reaction between 2-oxobutyrate and picolinaldehyde, the latter of which is derived from picolinic acid that is activated and loaded to coenzyme A by the aryl-activating adenylation enzyme, NikE. We now provide evidence that NikE is also involved in the activation and loading of the alpha-keto acid precursor, 4-(2'-pyridinyl)-2-oxo-4-hydroxyisovalerate (POHIV), to a phosphopantetheinyl group of an acyl carrier protein domain of NikT. POHIV was synthesized using Escherichia coli 2-dehydro-3-deoxy-phosphogluconate aldolase, and phenylalanine dehydrogenase from Bacillus sp. NRRL B-14911 was used to prepare the alpha-amino acid, 4-(2'-pyridinyl)-homothreonine (PHT). Using the carboxylic acid-dependent, ATP-[(32)P]PP(i) exchange assay, NikE is shown to activate both picolinic acid and POHIV but not PHT. Furthermore, NikE loads POHIV to holo-NikT to generate a new thioester-linked intermediate, which was not observed using a NikT(S33A) mutant. Thus, NikE activates two distinct carboxylic acids to form two new thioester intermediates, one of which is subsequently reduced to the aldehyde and the other that likely serves as a substrate for the aminotransferase domain of NikT prior to condensation with nikkomycin C(Z) to yield the dipeptide. Copyright 2010 Wiley Periodicals, Inc.
Polyamine biosynthesis during germination of yeast ascospores.

PubMed Central

Brawley, J V; Ferro, A J

1979-01-01

The role of the diamine putrescine during germination and outgrowth of ascospores of Saccharomyces cerevisiae was examined. Ornithine decarboxylase activity increased and declined rapidly during germination and outgrowth; peak activity was attained after the cells had proceeded through the G1 interval of the cell cycle, whereas minimal activity was present at the completion of the first cell division. alpha-Methylornithine inhibited both ornithine decarboxylase activity and the in vivo accumulation of putrescine. In the presence of alpha-methylornithireak dormancy and proceed through one cell division. Subsequent cellular growth, however, was retarded but not completely inhibited. The supplementation of Methylglyoxal bis(guanylhydrazone) to sporulation medium greatly inhibited this sexual process. These data suggest that the synthesis of putrescine is not required for the breaking of spore dormancy, but that polyamine biosynthesis may be essential for meiosis and sporulation. PMID:387744
Enantiomerically pure 3-aryl- and 3-hetaryl-2-hydroxypropanoic acids by chemoenzymatic reduction of 2-oxo acids.

PubMed

Sivanathan, Sivatharushan; Körber, Florian; Tent, Jannis Aron; Werner, Svenja; Scherkenbeck, Jürgen

2015-03-06

Phenyllactic acids are found in numerous natural products as well as in active substances used in medicine or plant protection. Enantiomerically pure phenyllactic acids are available by transition-metal-catalyzed hydrogenations or chemoenzymatic reductions of the corresponding 3-aryl-2-oxopropanoic acids. We show here that d-lactate dehydrogenase from Staphylococcus epidermidis reduces a broad spectrum of 2-oxo acids, which are difficult substrates for transition-metal-catalyzed reactions, with excellent enantioselectivities in a simple experimental setup.
Identification of 4-oxo-13-cis-retinoic acid as the major metabolite of 13-cis-retinoic acid in human blood.

PubMed

Vane, F M; Buggé, C J

1981-01-01

The metabolites of 13-cis-retinoic acid (Accutane) were investigated in blood samples from human volunteers on chronic treatment for dermatological disorders. The major metabolite was isolated by reverse-phase high-pressure liquid chromatography and identified as 4-oxo-13-cis-retinoic acid by comparison of its mass and NMR spectra to the spectra of the reference compound. 4-Oxo-all-trans-retinoic acid was also identified, but the extent to which this compound was a metabolite of 13-cis-retinoic acid or an artifactual isomerization product of the major metabolite is unknown. Chromatographic data suggested that small amounts of 13-cis-retinoic acid, 4-hydroxy-13-cis-retinoic acid, and dioxygenated metabolites of 13-cis-retinoic acid may also be present in the blood. This study indicates that a major metabolic pathway of 13-cis-retinoic acid in humans is oxidation at C4 of the cyclohexenyl group.
[Isolation, identification and fermentation optimization of Bacillus tequilensis PanD37 producing L-aspartate α- decarboxylase].

PubMed

Feng, Zhibin; Zhang, Juan; Chen, Guozhong; Cha, Yaping; Liu, Jinjie; Ge, Yihe; Cheng, Shiwei; Yu, Botao

2016-01-04

We screened bacteria producing L-aspartate α-decarboxylase from grapery soil and optimized the fermentation conditions. L-aspartate α-decarboxylase producing bacteria were screened by color-changing circle and liquid secondary screening culture media. Combination of morphological, physiological and biochemical characteristics and 16S rRNA sequence analysis were used to identify the bacteria. Fermentation conditions were optimized by single factor test and orthogonal experiment. Strain PanD37 showed high L-aspartate α-decarboxylase producing property and was identified as Bacillus tequilensis. The optimum fermentation conditions of PanD37 were liquid volume of 50 mL in 500 mL flask, 220 r/min at 35 °C, inoculation amount of 5% for 28 h with a medium of 22.5 g/L sucrose, 7.5 g/L fumaric acid, 20 g/L peptone, 6 g/L L-aspartic acid, 2 g/L Triton X-100, at initial pH of 7.0. Under the optimal fermentation conditions, the highest L-aspartate α-decarboxylase activity reached 44.57 U/mL, which was 2.57 folds higher than that obtained before optimization. Strain PanD37 was identified as Bacillus tequilensiswhich was capable of highly producing L-aspartate α-decarboxylase under the optimal fermentation conditions.
Identification of a second PAD1 in Brettanomyces bruxellensis LAMAP2480.

PubMed

González, Camila; Godoy, Liliana; Ganga, Ma Angélica

2017-02-01

Volatile phenols are aromatic compounds produced by some yeasts of the genus Brettanomyces as defense against the toxicity of hydroxycinnamic acids (p-coumaric acid, ferulic acid and caffeic acid). The origin of these compounds in winemaking involves the sequential action of two enzymes: coumarate decarboxylase and vinylphenol reductase. The first one converts hydroxycinnamic acids into hydroxystyrenes, which are then reduced to ethyl derivatives by vinylphenol reductase. Volatile phenols derived from p-coumaric acid (4-vinylphenol and 4-ethylphenol) have been described as the major contributors to self-defeating aromas associated with stable, gouache, wet mouse, etc., which generates large economic losses in the wine industry. The gene responsible for the production of 4-vinylphenol from p-coumaric acid has been identified as PAD1, which encodes a phenylacrylic acid decarboxylase. PAD1 has been described for many species, among them Candida albicans, Candida dubliniensis, Debaryomyces hansenii and Pichia anomala. In Brettanomyces bruxellensis LAMAP2480, a 666 bp reading frame (DbPAD) encodes a coumarate decarboxylase. Recent studies have reported the existence of a new reading frame belonging to DbPAD called DbPAD2 of 531 bp, which could encode a protein with similar enzymatic activity to PAD1. The present study confirmed that the transformation of Saccharomyces cerevisiae strain BY4722 with reading frame DbPAD2 under the control of the B. bruxellensis ACT1 promoter, encodes an enzyme with coumarate decarboxylase activity. This work has provided deeper insight into the origin of aroma defects in wine due to contamination by Brettanomyces spp.
[Influence of exogenous gamma-aminobutyric acid (GABA) on GABA metabolism and amino acid contents in roots of melon seedling under hypoxia stress].

PubMed

Wang, Chun-Yan; Li, Jing-Rui; Xia, Qing-Ping; Wu, Xiao-Lei; Gao, Hong-Bo

2014-07-01

This paper investigated the influence of gamma-aminobutyric acid (GABA) on GABA metabolism and amino acid content under hypoxia stress by accurately controlling the level of dissolved oxygen in hydroponics, using the roots of melon 'Xiyu 1' seedlings as the test material. The results showed that compared with the control, the growth of roots was inhibited seriously under hypoxia stress. Meanwhile, the hypoxia-treated roots had significantly higher activities of glutamate decarboxylase (GAD), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS), alanine aminotransferase (ALT), aspartate aminotransferase (AST) as well as the contents of GABA, pyruvic acid, alanine (Ala) and aspartic acid (Asp). But the contents of glutamic acid (Glu) and alpha-keto glutaric acid in roots under hypoxia stress was obviously lower than those of the control. Exogenous treatment with GABA alleviated the inhibition effect of hypoxia stress on root growth, which was accompanied by an increase in the contents of endogenous GABA, Glu, alpha-keto glutaric acid and Asp. Furthermore, under hypoxia stress, the activities of GAD, GDH, GOGAT, GS, ALT, AST as well as the contents of pyruvic acid and Ala significantly decreased in roots treated with GABA. However, adding GABA and viny-gamma-aminobutyric acid (VGB) reduced the alleviation effect of GABA on melon seedlings under hypoxia stress. The results suggested that absorption of GABA by roots could alleviate the injury of hypoxia stress to melon seedlings. This meant that GABA treatment allows the normal physiological metabolism under hypoxia by inhibiting the GAD activity through feedback and maintaining higher Glu content as well as the bal- ance of carbon and nitrogen.
Induction of peroxisomal beta-oxidation by a microbial catabolite of cholic acid in rat liver and cultured rat hepatocytes.

PubMed Central

Nishimaki-Mogami, T; Takahashi, A; Toyoda, K; Hayashi, Y

1993-01-01

The capability of (4R)-4-(2,3,4,6,6a beta,7,8,9,9a alpha,9b beta-decahydro-6a beta-methyl-3-oxo-1H-cyclopental[f]quinolin-7 beta-yl)valeric acid (DCQVA), a catabolite of cholic acid produced by enterobacteria, to induce peroxisome proliferation in vivo and in vitro was studied. Rats given 0.3% DCQVA in the diet for 2 weeks showed marked increases in peroxisomal beta-oxidation, mitochondrial 2,4-dienoyl-CoA reductase and microsomal laurate omega-oxidation activities in the liver compared with control rats given the diet without DCQVA. Cultured rat hepatocytes treated with DCQVA for 72 h also exhibited greatly enhanced beta-oxidation activity. The increased activity was concentration-dependent and the effective concentrations were comparable with those of clofibric acid that produced the same degree of induction in the assay. The results demonstrate that DCQVA is a potent peroxisome proliferator that occurs naturally in rat intestine. PMID:8216219

α-Oxo-Ketenimines from Isocyanides and α-Haloketones: Synthesis and Divergent Reactivity.

PubMed

Mamboury, Mathias; Wang, Qian; Zhu, Jieping

2017-09-18

The palladium-catalyzed reaction of α-haloketones with isocyanides afforded α-oxo-ketenimines through β-hydride elimination of the β-oxo-imidoyl palladium intermediates. Reaction of these relatively stable α-oxo-ketenimines with nucleophiles such as hydrazines, hydrazoic acid, amines, and Grignard reagent afforded pyrazoles, tetrazole, β-keto amidines, and enaminone, respectively, with high chemoselectivity. Whereas amines attack exclusively on the ketenimine functions, the formal [3+2] cycloaddition between N-monosubstituted hydrazines and α-oxo-ketenimines was initiated by nucleophilic addition to the carbonyl group. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Effects of down-regulating ornithine decarboxylase upon putrescine-associated metabolism and growth in Nicotiana tabacum L.

PubMed Central

Dalton, Heidi L.; Blomstedt, Cecilia K.; Neale, Alan D.; Gleadow, Ros; DeBoer, Kathleen D.; Hamill, John D.

2016-01-01

Transgenic plants of Nicotiana tabacum L. homozygous for an RNAi construct designed to silence ornithine decarboxylase (ODC) had significantly lower concentrations of nicotine and nornicotine, but significantly higher concentrations of anatabine, compared with vector-only controls. Silencing of ODC also led to significantly reduced concentrations of polyamines (putrescine, spermidine and spermine), tyramine and phenolamides (caffeoylputrescine and dicaffeoylspermidine) with concomitant increases in concentrations of amino acids ornithine, arginine, aspartate, glutamate and glutamine. Root transcript levels of S-adenosyl methionine decarboxylase, S-adenosyl methionine synthase and spermidine synthase (polyamine synthesis enzymes) were reduced compared with vector controls, whilst transcript levels of arginine decarboxylase (putrescine synthesis), putrescine methyltransferase (nicotine production) and multi-drug and toxic compound extrusion (alkaloid transport) proteins were elevated. In contrast, expression of two other key proteins required for alkaloid synthesis, quinolinic acid phosphoribosyltransferase (nicotinic acid production) and a PIP-family oxidoreductase (nicotinic acid condensation reactions), were diminished in roots of odc-RNAi plants relative to vector-only controls. Transcriptional and biochemical differences associated with polyamine and alkaloid metabolism were exacerbated in odc-RNAi plants in response to different forms of shoot damage. In general, apex removal had a greater effect than leaf wounding alone, with a combination of these injury treatments producing synergistic responses in some cases. Reduced expression of ODC appeared to have negative effects upon plant growth and vigour with some leaves of odc-RNAi lines being brittle and bleached compared with vector-only controls. Together, results of this study demonstrate that ornithine decarboxylase has important roles in facilitating both primary and secondary metabolism in Nicotiana. PMID:27126795
Genome-scale model guided design of Propionibacterium for enhanced propionic acid production.

PubMed

Navone, Laura; McCubbin, Tim; Gonzalez-Garcia, Ricardo A; Nielsen, Lars K; Marcellin, Esteban

2018-06-01

Production of propionic acid by fermentation of propionibacteria has gained increasing attention in the past few years. However, biomanufacturing of propionic acid cannot compete with the current oxo-petrochemical synthesis process due to its well-established infrastructure, low oil prices and the high downstream purification costs of microbial production. Strain improvement to increase propionic acid yield is the best alternative to reduce downstream purification costs. The recent generation of genome-scale models for a number of Propionibacterium species facilitates the rational design of metabolic engineering strategies and provides a new opportunity to explore the metabolic potential of the Wood-Werkman cycle. Previous strategies for strain improvement have individually targeted acid tolerance, rate of propionate production or minimisation of by-products. Here we used the P. freudenreichii subsp . shermanii and the pan- Propionibacterium genome-scale metabolic models (GEMs) to simultaneously target these combined issues. This was achieved by focussing on strategies which yield higher energies and directly suppress acetate formation. Using P. freudenreichii subsp . shermanii , two strategies were assessed. The first tested the ability to manipulate the redox balance to favour propionate production by over-expressing the first two enzymes of the pentose-phosphate pathway (PPP), Zwf (glucose-6-phosphate 1-dehydrogenase) and Pgl (6-phosphogluconolactonase). Results showed a 4-fold increase in propionate to acetate ratio during the exponential growth phase. Secondly, the ability to enhance the energy yield from propionate production by over-expressing an ATP-dependent phosphoenolpyruvate carboxykinase (PEPCK) and sodium-pumping methylmalonyl-CoA decarboxylase (MMD) was tested, which extended the exponential growth phase. Together, these strategies demonstrate that in silico design strategies are predictive and can be used to reduce by-product formation in Propionibacterium . We also describe the benefit of carbon dioxide to propionibacteria growth, substrate conversion and propionate yield.
Profiling of Amino Acids and Their Derivatives Biogenic Amines Before and After Antipsychotic Treatment in First-Episode Psychosis.

PubMed

Leppik, Liisa; Kriisa, Kärt; Koido, Kati; Koch, Kadri; Kajalaid, Kärolin; Haring, Liina; Vasar, Eero; Zilmer, Mihkel

2018-01-01

Schizophrenia (SCH) is a heterogeneous disorder, deriving from a potential multitude of etiopathogenetic factors. During the past few years there has been an increasing interest in the role of circulating amino acids (AAs) and biogenic amines (BAs) in the pathophysiology of SCH. In the present study, we aimed to provide an insight into the potential role of alterations in levels of AAs and BAs as well as examine their more specific metabolic shifts in relation to early stage of SCH. We measured 21 AAs and 17 BAs in serum samples of patients with first-episode psychosis (FEP) before and after 7-month antipsychotic treatment in comparison to control subjects (CSs). According to multivariate analysis, antipsychotic-naïve FEP patients had significantly higher levels of taurine and spermine, whereas values of proline (Pro), alpha-aminoadipic acid (alpha-AAA), kynurenine (Kyn), valine (Val), tyrosine (Tyr), citrulline (Citr), tryptophan (Trp), and histidine (His) were diminished compared to CSs. Increased levels of taurine and spermine, as well as reduced levels of alpha-AAA and Kyn probably reflect the compromised function of N -methyl-D-aspartate (NMDA) receptors in patients. The decreased levels of Pro (AA modulating the function of glutamate decarboxylase) likely reflect the imbalanced function of gamma-aminobutyric acid (GABA) system in the brain of FEP patients. The alterations in ratio between Tyr and phenylalanine (Phe) can be taken as a sign of compromised function of dopaminergic system. These metabolic shifts were reinstated by 7-month antipsychotic treatment. Serum metabolic profiles can be regarded as important indicators to investigate clinical course of SCH and treatment response.
Cold generation of smoke flavour by the first phenolic acid decarboxylase from a filamentous ascomycete - Isaria farinosa.

PubMed

Linke, Diana; Riemer, Stephanie J L; Schimanski, Silke; Nieter, Annabel; Krings, Ulrich; Berger, Ralf G

2017-09-01

A decarboxylase (IfPAD) from the ascomycete Isaria farinosa converted ferulic acid to 4-vinylguaiacol (4-VG), a volatile which imparts the distinct "smoke flavor" of pyrolized wood. The activity was enhanced by adding (E)-ferulic acid to the culture medium and peaked with 3.6 U g -1 mycelium (1 μmol 4-VG min -1 ). The coding sequence of 543 bp was translated into a 25 kDa protein with a homology of 91 % to putative phenolic acid decarboxylases of its teleomorph, Cordyceps militaris, and Beauveria bassiana, the anamorph of Cordyceps bassiana. Cold shock expression in Escherichia coli yielded 411 U g -1 wet mass. Substrate conversion required a hydroxyl substituent para to a trans-unsaturated C3-side chain of the aromatic ring. K m and k cat /K m values were determined to 0.3 mM and 78.4 mM -1 s -1 for p-coumaric acid and 1.9 mM and 45.1 mM -1 s -1 for (E)-ferulic acid, respectively. The native enzyme and its recombinant counterpart showed pH-optima at pH 6.0 and pH 5.5, and low temperature optima of 19 °C and 14 °C, respectively. IfPAD produced 4-VG from destarched wheat bran and sugar beet fiber, confirming activity on complex plant biomass. This is the first report on the biochemical characterization of a phenolic acid decarboxylase from a filamentous ascomycete. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.
Delineation of the Caffeine C-8 Oxidation Pathway in Pseudomonas sp. Strain CBB1 via Characterization of a New Trimethyluric Acid Monooxygenase and Genes Involved in Trimethyluric Acid Metabolism

PubMed Central

Mohanty, Sujit Kumar; Yu, Chi-Li; Das, Shuvendu; Louie, Tai Man; Gakhar, Lokesh

2012-01-01

The molecular basis of the ability of bacteria to live on caffeine via the C-8 oxidation pathway is unknown. The first step of this pathway, caffeine to trimethyluric acid (TMU), has been attributed to poorly characterized caffeine oxidases and a novel quinone-dependent caffeine dehydrogenase. Here, we report the detailed characterization of the second enzyme, a novel NADH-dependent trimethyluric acid monooxygenase (TmuM), a flavoprotein that catalyzes the conversion of TMU to 1,3,7-trimethyl-5-hydroxyisourate (TM-HIU). This product spontaneously decomposes to racemic 3,6,8-trimethylallantoin (TMA). TmuM prefers trimethyluric acids and, to a lesser extent, dimethyluric acids as substrates, but it exhibits no activity on uric acid. Homology models of TmuM against uric acid oxidase HpxO (which catalyzes uric acid to 5-hydroxyisourate) reveal a much bigger and hydrophobic cavity to accommodate the larger substrates. Genes involved in the caffeine C-8 oxidation pathway are located in a 25.2-kb genomic DNA fragment of CBB1, including cdhABC (coding for caffeine dehydrogenase) and tmuM (coding for TmuM). Comparison of this gene cluster to the uric acid-metabolizing gene cluster and pathway of Klebsiella pneumoniae revealed two major open reading frames coding for the conversion of TM-HIU to S-(+)-trimethylallantoin [S-(+)-TMA]. The first one, designated tmuH, codes for a putative TM-HIU hydrolase, which catalyzes the conversion of TM-HIU to 3,6,8-trimethyl-2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (TM-OHCU). The second one, designated tmuD, codes for a putative TM-OHCU decarboxylase which catalyzes the conversion of TM-OHCU to S-(+)-TMA. Based on a combination of enzymology and gene-analysis, a new degradative pathway for caffeine has been proposed via TMU, TM-HIU, TM-OHCU to S-(+)-TMA. PMID:22609920
40 CFR 180.1281 - S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2-enyl)-3-methyl-penta-(2Z,4E...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false S-Abscisic Acid, (S)-5-(1-hydroxy-2,6... Exemptions From Tolerances § 180.1281 S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2... from the requirement of a tolerance is established for residues of S-Abscisic Acid in or on all food...
Divergent prebiotic synthesis of pyrimidine and 8-oxo-purine ribonucleotides

NASA Astrophysics Data System (ADS)

Stairs, Shaun; Nikmal, Arif; Bučar, Dejan-Krešimir; Zheng, Shao-Liang; Szostak, Jack W.; Powner, Matthew W.

2017-05-01

Understanding prebiotic nucleotide synthesis is a long standing challenge thought to be essential to elucidating the origins of life on Earth. Recently, remarkable progress has been made, but to date all proposed syntheses account separately for the pyrimidine and purine ribonucleotides; no divergent synthesis from common precursors has been proposed. Moreover, the prebiotic syntheses of pyrimidine and purine nucleotides that have been demonstrated operate under mutually incompatible conditions. Here, we tackle this mutual incompatibility by recognizing that the 8-oxo-purines share an underlying generational parity with the pyrimidine nucleotides. We present a divergent synthesis of pyrimidine and 8-oxo-purine nucleotides starting from a common prebiotic precursor that yields the β-ribo-stereochemistry found in the sugar phosphate backbone of biological nucleic acids. The generational relationship between pyrimidine and 8-oxo-purine nucleotides suggests that 8-oxo-purine ribonucleotides may have played a key role in primordial nucleic acids prior to the emergence of the canonical nucleotides of biology.
HU participates in expression of a specific set of genes required for growth and survival at acidic pH in Escherichia coli.

PubMed

Bi, Hongkai; Sun, Lianle; Fukamachi, Toshihiko; Saito, Hiromi; Kobayashi, Hiroshi

2009-05-01

The major histone-like Escherichia coli protein, HU, is composed of alpha and beta subunits respectively encoded by hupA and hupB in Escherichia coli. A mutant deficient in both hupA and hupB grew at a slightly slower rate than the wild type at pH 7.5. Growth of the mutant diminished with a decrease in pH, and no growth was observed at pH 4.6. Mutants of either hupA or hupB grew at all pH levels tested. The arginine-dependent survival at pH 2.5 was diminished approximately 60-fold by the deletion of both hupA and hupB, whereas the survival was slightly affected by the deletion of either hupA or hupB. The mRNA levels of adiA and adiC, which respectively encode arginine decarboxylase and arginine/agmatine antiporter, were low in the mutant deficient in both hupA and hupB. The deletion of both hupA and hupB had little effect on survival at pH 2.5 in the presence of glutamate or lysine, and expression of the genes for glutamate and lysine decarboxylases was not impaired by the deletion of the HU genes. These results suggest that HU regulates expression of the specific set of genes required for growth and survival in acidic environments.
Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

PubMed

Hayashi, T; Kawasaki, M; Okamura, K; Tamada, Y; Morita, N; Tezuka, Y; Kikuchi, T; Miwa, Y; Taga, T

1992-12-01

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.
Effects of diamines on ornithine decarboxylase activity in control and virally transformed mouse fibroblasts.

PubMed Central

Bethell, D R; Pegg, A E

1979-01-01

1. The induction of ornithine decarboxylase activity in mouse 3T3 fibroblasts or an SV-40 transformed 3T3 cell line by serum was prevented by addition of the naturally occurring polyamines putrescine (butane-1,4-diamine) and spermidine. Much higher concentrations of these amines were required to fully suppress ornithine decarboxylase activity in the transformed SV-3T3 cells than in the 3T3 fibroblasts. 2. Synthetic alpha omega-diamines with 3--12 carbon atoms also prevented the increase in ornithine decarboxylase activity induced by serum in these cells. The longer chain diamines were somewhat more potent than propane-1,3-diamine in this effect, but the synthetic diamines were less active than putrescine in the 3T3 cells. There was little difference between the responses of 3T3 and SV-3T3 cells to the synthetic diamines propane-1,3-diamine and heptane-1,7-diamine. 3. These results are discussed in relation to the control of polyamine synthesis in mammalian cells. PMID:486108
Anti-inflammatory agents from Sandoricum koetjape Merr.

PubMed

Rasadah, M A; Khozirah, S; Aznie, A A; Nik, M M

2004-02-01

The anti-inflammatory activity of the stem extracts of Sandoricum koetjape was investigated on topical administration using the TPA (tetradecanoylphorbol acetate)-induced mouse ear inflammation model. Bioassay-guided chromatographic fractionation of active fractions led to the isolation 3-oxo-12-oleanen-29-oic acid and katonic acid as the bioactive principles responsible for the anti-inflammatory acitivity. The percentage of inhibition exhibited by 3-oxo-12-oleanen-29-oic acid was almost equivalent to indomethacin.
Synthesis, biological evaluation, and 3D QSAR study of 2-methyl-4-oxo-3-oxetanylcarbamic acid esters as N-acylethanolamine acid amidase (NAAA) inhibitors.

PubMed

Ponzano, Stefano; Berteotti, Anna; Petracca, Rita; Vitale, Romina; Mengatto, Luisa; Bandiera, Tiziano; Cavalli, Andrea; Piomelli, Daniele; Bertozzi, Fabio; Bottegoni, Giovanni

2014-12-11

N-(2-Oxo-3-oxetanyl)carbamic acid esters have recently been reported to be noncompetitive inhibitors of the N-acylethanolamine acid amidase (NAAA) potentially useful for the treatment of pain and inflammation. In the present study, we further explored the structure-activity relationships of the carbamic acid ester side chain of 2-methyl-4-oxo-3-oxetanylcarbamic acid ester derivatives. Additional favorable features in the design of potent NAAA inhibitors have been found together with the identification of a single digit nanomolar inhibitor. In addition, we devised a 3D QSAR using the atomic property field method. The model turned out to be able to account for the structural variability and was prospectively validated by designing, synthesizing, and testing novel inhibitors. The fairly good agreement between predictions and experimental potency values points to this 3D QSAR model as the first example of quantitative structure-activity relationships in the field of NAAA inhibitors.
Fimasartan Ameliorates Nonalcoholic Fatty Liver Disease through PPARδ Regulation in Hyperlipidemic and Hypertensive Conditions

PubMed Central

Jang, Yoo-Na; Han, Yoon-Mi; Kim, Hyun-Min; Jeong, Jong-Min

2017-01-01

To investigate the effects of fimasartan on nonalcoholic fatty liver disease in hyperlipidemic and hypertensive conditions, the levels of biomarkers related to fatty acid metabolism were determined in HepG2 and differentiated 3T3-L1 cells treated by high fatty acid and liver and visceral fat tissue samples of spontaneously hypertensive rats (SHRs) given high-fat diet. In HepG2 cells and liver tissues, fimasartan was shown to increase the protein levels of peroxisome proliferator-activated receptor delta (PPARδ), phosphorylated 5′ adenosine monophosphate-activated protein kinase (p-AMPK), phosphorylated acetyl-CoA carboxylase (p-ACC), malonyl-CoA decarboxylase (MCD), medium chain acyl-CoA dehydrogenase (MCAD), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and it led to a decrease in the protein levels of 11 beta-hydroxysteroid dehydrogenase 1 (11β-HSDH1), fatty acid synthase (FAS), and tumor necrosis factor-alpha (TNF-α). Fimasartan decreased lipid contents in HepG2 and differentiated 3T3-L1 cells and liver tissues. In addition, fimasartan increased the adiponectin level in visceral fat tissues. The antiadipogenic effects of fimasartan were offset by PPARδ antagonist (GSK0660). Consequently, fimasartan ameliorates nonalcoholic fatty liver disease mainly through the activation of oxidative metabolism represented by PPARδ-AMPK-PGC-1α pathway. PMID:28386270
Engineering acyclic stereocontrol in the alkylation of vinylglycine-derived dianions: asymmetric synthesis of higher alpha-vinyl amino acids.

PubMed

Berkowitz, D B; McFadden, J M; Sloss, M K

2000-05-19

A generalizable synthesis of higher L-alpha-vinyl amino acids is presented. The strategy pursued here involves the introduction of the amino acid side chain via the alkylation of a chiral, vinylglycine-derived dianionic dienolate, bearing the (-)-8-(beta-naphthyl)menthyl (d'Angelo) auxiliary. A model is presented that postulates a favored "exo-entended" conformation for this dienolate, leading to C(alpha)-alkylation at the si face. The model invokes internal amidate chelation to control ester enolate geometry and soft-soft interactions between the polarizable beta-naphthyl ring of the auxiliary and the extended pi-system of the dienolate to shield the re face. Heats of formation for four conformers of this dianion were calculated for their semiempirical optimized geometries (PM3). The results support the notion that in these vinylglycine-derived dianionic dienolates, "exo" conformations are considerable lower in energy than their "endo" counterparts, with the "exo-entended" conformation being most favorable. In fact, the d'Angelo auxiliary gives a greater degree of acyclic stereocontrol in this system when compared with the (-)-8-phenylmenthyl (Corey) and trans-2-(beta-naphthyl)cyclohexyl auxiliaries, using isobutyl iodide and benzyl bromide as model electrophiles. These dianions are generated from the corresponding dehydrobutyrine esters via sequential deprotonation with LDA and n-BuLi (2 equiv). When alkylations are carried out at -78 degrees C in THF-HMPA, they proceed in 65-81% yields, with both regiocontrol (deconjugative alpha-alkylation is preferred over gamma-alkylation) and a great degree of acyclic stereocontrol [91:9 to >/=98:2 diastereomeric ratios (10 examples)]. The auxiliary may be recovered in high yield (generally 90%) using a modification of Gassman's "anhydrous hydroxide" conditions, in which considerably higher temperatures are employed. Among the side chains introduced directly are those of butyrine, leucine, ornithine, phenylalanine, aspartate, valine, and norvaline. The lysine side chain is elaborated via a 4-step sequence from the alkylation product obtained with 1-chloro-4-iodobutane as electrophile. Importantly, to our knowledge, this work represents the first asymmetric synthesis of L-alpha-vinyl analogues of m-tyrosine, ornithine, and lysine, known time-dependent inhibitors for amino acid decarboxylases.
Reduction of α-oxo carboxyylic acids by pigeon liver `malic' enzyme

PubMed Central

Tang, Chung L.; Hsu, Robert Y.

1973-01-01

1. Pigeon liver `malic' enzyme [l-malate–NADP+ oxidoreductase (decarboxylating); EC 1.1.1.40] was shown to catalyse the reductase reaction: [Formula: see text] l-Malate was identified as the reaction product, and was formed in stoicheiometric amount. 2. In addition to oxaloacetate and pyruvate, a number of other α-oxo carboxylic acids were also reduced. PMID:4764261
Initial evaluation of 99m Tc-tricarbonyl-cyclopentadienyl fatty acids derivatives as SPECT tracers for myocardium.

PubMed

Liu, Jianping; Wang, Huan; Wang, Shuxia; Xue, Qianqian; Wang, Dawei; Wang, Hang; Zhang, Huabei

2017-05-15

Fatty acids are myocardial metabolic agent for detecting myocardial ischemia and infraction. However, no 99m Tc-labeled fatty acids had potential use in clinical practice. In this study, 99m Tc-CpTT-10-oxo-para-PPA (1d), 99m Tc-CpTT-11-oxo-para-PPA (2d), 99m Tc-CpTT-12-oxo-para-PPA (3d), 99m Tc-CpTT-11-oxo-ortho-PPA (4d), and 99m Tc-CpTT-11-oxo-meta-PPA (5d) were synthesized by a double ligand transfer reaction, and their biological behaviors were investigated. Compound 2d achieved good heart to blood ratio (3.39 at 5 min after intravenous), and 2d showed high-heart uptake of 6.20% ID/g at 5 minutes after injection. Compound 3d displayed a prolonged retention in the myocardium (1.43% ID/g at 60 min after injection). Radioactivity accumulation in the lungs, spleen, and blood was eliminated rapidly. In vivo, metabolite analysis presented that compound 6d may be metabolite of 2d through β-oxidation in tissue. Unfortunately, the biodistribution studies of 1d, 2d, 3d, 4d, and 5d showed fast heart clearance and poor heart to liver ratios, which suggested that the 5 99m Tc-labeled fatty acid analogues cannot be used for diagnosis. Copyright © 2017 John Wiley & Sons, Ltd.
DPD epitope-specific glutamic acid decarboxylase GAD)65 autoantibodies in children with Type 1 diabetes

USDA-ARS?s Scientific Manuscript database

To study whether DPD epitope-specific glutamate decarboxylase autoantibodies are found more frequently in children with milder forms of Type 1 diabetes. We prospectively evaluated 75 children with new-onset autoimmune Type 1 diabetes, in whom we collected demographic, anthropometric and clinical dat...
Synthesis of 24-phenyl-24-oxo steroids derived from bile acids by palladium-catalyzed cross coupling with phenylboronic acid. NMR characterization and X-ray structures.

PubMed

Mayorquín-Torres, Martha C; Romero-Ávila, Margarita; Flores-Álamo, Marcos; Iglesias-Arteaga, Martin A

2013-11-01

Palladium-catalyzed cross coupling of phenyboronic acid with acetylated bile acids in which the carboxyl functions have been activated by formation of a mixed anhydride with pivalic anhydride afforded moderate to good yield of 24-phenyl-24-oxo-steroids. Unambiguous assignments of the NMR signals were made with the aid of combined 1D and 2D NMR techniques. X-ray diffraction studies confirmed the obtained structures. Copyright © 2013 Elsevier Inc. All rights reserved.
Conformationally constrained dipeptide surrogates with aromatic side-chains: synthesis of 4-aryl indolizidin-9-one amino acids by conjugate addition to a common alpha,omega-diaminoazelate enone intermediate.

PubMed

Cluzeau, Jérôme; Lubell, William D

2004-03-05

Four methyl 9-oxo-8-(N-(Boc)-amino)-4-phenyl-1-azabicyclo[4.3.0]nonane carboxylates (11, 4-Ph-I(9)aa-OMe) were synthesized from (2S,8S,5E)-di-tert-butyl-4-oxo-5-ene-2,8-bis[N-(PhF)amino]azelate [(5E)-7, PhF = 9-(9-phenylfluorenyl)] via a seven-step process featuring a conjugate addition/reductive amination/lactam cyclization sequence. Various nucleophiles were used in the conjugate addition reactions on enone (5E)-7 as a general route for making alpha,omega-diaminoazelates possessing different substituents in good yield albeit low diastereoselectivity except in the case of aryl Grignard reagents (9/1 to 15/1 drs). 6-Phenylazelates (6S)-8d and (6R)-8d were separated by chromatography and diastereoselective precipitation and independently transformed into 4-Ph-I(9)aa-OMe. From (6S)-8d, (2S,4R,6R,8S)-4-Ph-I(9)aa-OMe 11 was prepared selectively in 51% yield. Reductive amination of (6R)-8d provided the desired pipecolates 9 along with desamino compound 10, which was minimized by performing the hydrogenation in the presence of ammonium acetate. Subsequent ester exchange, lactam cyclization, and amine protection provided three products (2R,4S,6S,8R)-, (2R,4S,6S,8S)-, and (2S,4S,6R,8S)-4-Ph-I(9)aa-OMe 11 in 10, 6, and 6% yields, respectively, from (6R)-8d. Ester hydrolysis of (2S,4R,6R,8S)-11 furnished 4-phenyl indolizidin-9-one N-(Boc)amino acid 3 as a novel constrained Ala-Phe dipeptide surrogate for studying conformation-activity relationships of biologically active peptides.

Microbiological and chemical transformations of argentatin B.

PubMed

Maatooq, Galal T

2003-01-01

Argentatin B is a naturally occurring tetracyclic triterpene isolated from Parthenium argentatum x P. tomentosa. It was microbiologically transformed to 16, 24-epoxycycloartan-3alpha, 25-diol, (isoargentatin D), by Nocardia corallina var. taoka ATCC 31338, Mycobacterium species NRRL B3683 and Septomyxa affinis ATCC 6737. The later microbe also produced 16, 24-epoxycycloartan-3beta, 25-diol (argentatin D) and 1, 2-didehydroargentatin B, (isoargentatin D). Sodium hydroxide converted argentatin B to argentatin D and isoargentatin D. Hydrochloric acid treatment gave cycloartan-25-ol-3, 24-dione. Cerium sulfate/sulfuric acid/aqueous methanol induced scission of the isopropanol moiety and provided an isomeric mixture of 24-methoxy-25-27-trinorargentatin B. Oxidation of this isomeric mixture with pyridinium chlorochromate, selectively, attacked the isomer with the equatorial proton at position-24 to give the corresponding lactone, 24-oxo-25-27-trinorargentatin B. The produced compounds were characterized by spectroscopic methods.
Structural and functional comparison of two human liver dihydrodiol dehydrogenases associated with 3 alpha-hydroxysteroid dehydrogenase activity.

PubMed Central

Deyashiki, Y; Taniguchi, H; Amano, T; Nakayama, T; Hara, A; Sawada, H

1992-01-01

Two monomeric dihydrodiol dehydrogenases with pI values of 5.4 and 7.6 were co-purified with androsterone dehydrogenase activity to homogeneity from human liver. The two enzymes differed from each other on peptide mapping and in their heat-stabilities; with respect to the latter the dihydrodiol dehydrogenase and 3 alpha-hydroxysteroid dehydrogenase activities of the respective enzymes were similarly inactivated. The pI 5.4 enzyme was equally active towards trans- and cis-benzene dihydrodiols, and towards (S)- and (R)-forms of indan-1-ol and 1,2,3,4-tetrahydronaphth-1-ol and oxidized the 3 alpha-hydroxy group of C19-, C21- and C24-steroids, whereas the pI 7.6 enzyme showed high specificity for trans-benzene dihydrodiol, (S)-forms of the alicyclic alcohols and C19- and C21-steroids. Although the two enzymes reduced various xenobiotic carbonyl compounds and the 3-oxo group of C19- and C21-steroids, and were A-specific in the hydrogen transfer from NADPH, only the pI 5.4 enzyme showed reductase activity towards 7 alpha-hydroxy-5 beta-cholestan-3-one and dehydrolithocholic acid. The affinity of the two enzymes for the steroidal substrates was higher than that for the xenobiotic substrates. The two enzymes also showed different susceptibilities to the inhibition by anti-inflammatory drugs and bile acids. Whereas the pI-5.4 enzyme was highly sensitive to anti-inflammatory steroids, showing mixed-type inhibitions with respect to indan-1-ol and androsterone, the pI 7.6 enzyme was inhibited more potently by non-steroidal anti-inflammatory drugs and bile acids than by the steroidal drugs, and the inhibitions were all competitive. These structural and functional differences suggest that the two enzymes are 3 alpha-hydroxysteroid dehydrogenase isoenzymes. Images Fig. 2. PMID:1554355
Expression of the Aspergillus terreus itaconic acid biosynthesis cluster in Aspergillus niger

PubMed Central

2014-01-01

Background Aspergillus terreus is a natural producer of itaconic acid and is currently used to produce itaconic acid on an industrial scale. The metabolic process for itaconic acid biosynthesis is very similar to the production of citric acid in Aspergillus niger. However, a key enzyme in A. niger, cis-aconitate decarboxylase, is missing. The introduction of the A. terreus cadA gene in A. niger exploits the high level of citric acid production (over 200 g per liter) and theoretically can lead to production levels of over 135 g per liter of itaconic acid in A. niger. Given the potential for higher production levels in A. niger, production of itaconic acid in this host was investigated. Results Expression of Aspergillus terreus cis-aconitate decarboxylase in Aspergillus niger resulted in the production of a low concentration (0.05 g/L) of itaconic acid. Overexpression of codon-optimized genes for cis-aconitate decarboxylase, a mitochondrial transporter and a plasma membrane transporter in an oxaloacetate hydrolase and glucose oxidase deficient A. niger strain led to highly increased yields and itaconic acid production titers. At these higher production titers, the effect of the mitochondrial and plasma membrane transporters was much more pronounced, with levels being 5–8 times higher than previously described. Conclusions Itaconic acid can be produced in A. niger by the introduction of the A. terreus cis-aconitate decarboxylase encoding cadA gene. This results in a low itaconic acid production level, which can be increased by codon-optimization of the cadA gene for A. niger. A second crucial requirement for efficient production of itaconic acid is the expression of the A. terreus mttA gene, encoding a putative mitochondrial transporter. Expression of this transporter results in a twenty-fold increase in the secretion of itaconic acid. Expression of the A. terreus itaconic acid cluster consisting of the cadA gene, the mttA gene and the mfsA gene results in A. niger strains that produce over twenty five-fold higher levels of itaconic acid and show a twenty-fold increase in yield compared to a strain expressing only CadA. PMID:24438100
Expression of the Aspergillus terreus itaconic acid biosynthesis cluster in Aspergillus niger.

PubMed

van der Straat, Laura; Vernooij, Marloes; Lammers, Marieke; van den Berg, Willy; Schonewille, Tom; Cordewener, Jan; van der Meer, Ingrid; Koops, Andries; de Graaff, Leo H

2014-01-17

Aspergillus terreus is a natural producer of itaconic acid and is currently used to produce itaconic acid on an industrial scale. The metabolic process for itaconic acid biosynthesis is very similar to the production of citric acid in Aspergillus niger. However, a key enzyme in A. niger, cis-aconitate decarboxylase, is missing. The introduction of the A. terreus cadA gene in A. niger exploits the high level of citric acid production (over 200 g per liter) and theoretically can lead to production levels of over 135 g per liter of itaconic acid in A. niger. Given the potential for higher production levels in A. niger, production of itaconic acid in this host was investigated. Expression of Aspergillus terreus cis-aconitate decarboxylase in Aspergillus niger resulted in the production of a low concentration (0.05 g/L) of itaconic acid. Overexpression of codon-optimized genes for cis-aconitate decarboxylase, a mitochondrial transporter and a plasma membrane transporter in an oxaloacetate hydrolase and glucose oxidase deficient A. niger strain led to highly increased yields and itaconic acid production titers. At these higher production titers, the effect of the mitochondrial and plasma membrane transporters was much more pronounced, with levels being 5-8 times higher than previously described. Itaconic acid can be produced in A. niger by the introduction of the A. terreus cis-aconitate decarboxylase encoding cadA gene. This results in a low itaconic acid production level, which can be increased by codon-optimization of the cadA gene for A. niger. A second crucial requirement for efficient production of itaconic acid is the expression of the A. terreus mttA gene, encoding a putative mitochondrial transporter. Expression of this transporter results in a twenty-fold increase in the secretion of itaconic acid. Expression of the A. terreus itaconic acid cluster consisting of the cadA gene, the mttA gene and the mfsA gene results in A. niger strains that produce over twenty five-fold higher levels of itaconic acid and show a twenty-fold increase in yield compared to a strain expressing only CadA.
Enhancement of the catalytic activity of ferulic acid decarboxylase from Enterobacter sp. Px6-4 through random and site-directed mutagenesis.

PubMed

Lee, Hyunji; Park, Jiyoung; Jung, Chaewon; Han, Dongfei; Seo, Jiyoung; Ahn, Joong-Hoon; Chong, Youhoon; Hur, Hor-Gil

2015-11-01

The enzyme ferulic acid decarboxylase (FADase) from Enterobacter sp. Px6-4 catalyzes the decarboxylation reaction of lignin monomers and phenolic compounds such as p-coumaric acid, caffeic acid, and ferulic acid into their corresponding 4-vinyl derivatives, that is, 4-vinylphenol, 4-vinylcatechol, and 4-vinylguaiacol, respectively. Among various ferulic acid decarboxylase enzymes, we chose the FADase from Enterobacter sp. Px6-4, whose crystal structure is known, and produced mutants to enhance its catalytic activity by random and site-directed mutagenesis. After three rounds of sequential mutations, FADase(F95L/D112N/V151I) showed approximately 34-fold higher catalytic activity than wild-type for the production of 4-vinylguaiacol from ferulic acid. Docking analyses suggested that the increased activity of FADase(F95L/D112N/V151I) could be due to formation of compact active site compared with that of the wild-type FADase. Considering the amount of phenolic compounds such as lignin monomers in the biomass components, successfully bioengineered FADase(F95L/D112N/V151I) from Enterobacter sp. Px6-4 could provide an ecofriendly biocatalytic tool for producing diverse styrene derivatives from biomass.
[Microbial transformation of glycyrrhetinic acid by Cunninghamella blakesleeana].

PubMed

Ma, Yuan; Xie, Dan; Wang, Zhao-hua; Dai, Jun-gui; An, Xi-qiang; Gu, Zheng-yi

2015-11-01

A study on the microbial transformation of glycyrrhetinic acid (GA) was conducted by a fungus, Cunninghamella blakesleeana CGMCC 3.970 systematically. After incubation with the cell cultures of C. blakesleeana CGMCC 3.970 at 25 degrees C for 7 days on a rotary shaker operating at 135 r x min(-1), GA was converted into one major product and five minor products. The products were extracted and purified by solvent extraction, macroporous adsorbent resin, silica gel column chromatography, and semi-preparative RP-HPLC chromatography. Their structures were identified as 3-oxo-15α-hydroxy-18β-glycyrrhetinic acid(1), 3-oxo-15β-hydroxy-18β-glycyrrhetinic acid (2), 7β,15α-dihydroxy-18β-glycyrrhetinic acid (3), 3-oxo-7β, 15α-dihydroxy-18β-glycyrrhetinic acid (4), 7β-hydroxy-18β-glycyrrhetinic acid(5) and 15α-hydroxy-18β-glycyrrhetinic acid(6) by the analyses of MS, 1H-NMR and 13C-NMR spectroscopic data respectively. Among them, 2 was a new compound. These results suggest that C. blakesleeana CGMCC 3.970 has the capability of selective ketonization and hydroxylation for GA. [Key words] glycyrrhetinic acid; Cunninghamella blakesleeana CGMCC 3. 970; microbial transformation
Ability of m-chloroperoxybenzoic acid to induce the ornithine decarboxylase marker of skin tumor promotion and inhibition of this response by gallotannins, oligomeric proanthocyanidins, and their monomeric units in mouse epidermis in vivo

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Steven W. Newell; Vittorio Bottari; Richard W. Hemingway; Jean-Pierre Perchellet

1995-01-01

m-Chloroperoxybenzoic acid (CPBA) was tested for its ability to induce the ornithine decarboxylase (ODC) marker of skin tumor promotion. In contrast to benzoyl peroxide, dicumyl peroxide, and 2-butanol peroxide, 5 mg of CPBA applied twice at a 72-h interval induce DOC activity at least as much as 3 Âµg of 12-O-tetradecanoylphorbol-13.acetate (TPA)....
Ability of m-chloroperoxybenzoic acid to induce the ornithine decarboxylase marker of skin tumor promotion and inhibition of this response by gallotannins, oligomeric proanthocyanidins, and their monomeric units in mouse epidermis in Vivo

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Steven W. Newell; richard W. Hemingway; Vittorio Bottari; Jean-Pierre Perchellet

1995-01-01

m-Chloroperoxybenzoic acid (CPBA) was tested for its ability to induce the ornithine decarboxylase (ODC) marker of skin tumor promotion. In contrast to benzoyl peroxide, dicumyl peroxide, and 2-butanol peroxide, 5 mg of CPBA applied twice at a 72-h interval induce ODC activity at least as much as 3 ug of 12-O-tetradecanoylphorbol-13-acetate (TPA). ODC induction peaks...
21 CFR 74.2705 - FD&C Yellow No. 5.

Code of Federal Regulations, 2010 CFR

2010-04-01

... salt, not more than 0.2 percent. 4,5-Dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid, disodium salt, not more than 0.2 percent. Ethyl or methyl 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3...-sulfophenyl)azo]-1H-pyrazole-3-carboxylic acid (CAS Reg. No. 1934-21-0). To manufacture the additive, 4...
In vivo mechanism-based inactivation of S-adenosylmethionine decarboxylases from Escherichia coli, Salmonella typhimurium, and Saccharomyces cerevisiae.

PubMed

Li, Y F; Hess, S; Pannell, L K; White Tabor, C; Tabor, H

2001-09-11

S-adenosylmethionine decarboxylase (AdoMetDC), a key enzyme in the biosynthesis of spermidine and spermine, is first synthesized as a proenzyme, which is cleaved posttranslationally to form alpha and beta subunits. The alpha subunit contains a covalently bound pyruvoyl group derived from serine that is essential for activity. With the use of an Escherichia coli overexpression system, we have purified AdoMetDCs encoded by the E. coli, Saccharomyces cerevisiae, and Salmonella typhimurium genes. Unexpectedly we found by mass spectrometry that these enzymes had been modified posttranslationally in vivo by a mechanism-based "suicide" inactivation. A large percentage of the alpha subunit of each enzyme had been modified in vivo to give peaks with masses m/z = 57 +/- 1 and m/z = 75 +/- 1 daltons higher than the parent peak. AdoMetDC activity decreased markedly during overexpression concurrently with the increase of the additional peaks for the alpha subunit. Sequencing of a tryptic fragment by tandem mass spectrometry showed that Cys-140 was modified with a +75 +/- 1 adduct, which is probably derived from the reaction product. Comparable modification of the alpha subunit was also observed in in vitro experiments after incubation with the substrate or with the reaction product, which is consistent with the in vitro alkylation of E. coli AdoMetDC reported by Diaz and Anton [Diaz, E. & Anton, D. L. (1991) Biochemistry 30, 4078-4081].
cis-Stilbene and (1 alpha,2 beta,3 alpha)-(2-ethenyl-3-methoxycyclopropyl)benzene as mechanistic probes in the Mn(III)(salen)-catalyzed epoxidation: influence of the oxygen source and the counterion on the diastereoselectivity of the competitive concerted and radical-type oxygen transfer.

PubMed

Adam, Waldemar; Roschmann, Konrad J; Saha-Möller, Chantu R; Seebach, Dieter

2002-05-08

cis-Stilbene (1) has been epoxidized by a set of diverse oxygen donors [OxD], catalyzed by the Mn(III)(salen)X complexes 3 (X = Cl, PF(6)), to afford a mixture of cis- and trans-epoxides 2. The cis/trans ratios range from 29:71 (extensive isomerization) to 92:8, which depends both on the oxygen source [OxD] and on the counterion X of the catalyst. When (1 alpha,2 beta,3 alpha)-(2-ethenyl-3-methoxycyclopropyl)-benzene (4) is used as substrate, a mechanistic probe which differentiates between radical and cationic intermediates, no cationic ring-opening products are found in this epoxidation reaction; thus, isomerized epoxide product arises from intermediary radicals. The dependence of the diastereoselectivity on the oxygen source is rationalized in terms of a bifurcation step in the catalytic cycle, in which concerted Lewis-acid-activated oxygen transfer competes with stepwise epoxidation by the established Mn(V)(oxo) species. The experimental counterion effect is attributed to the computationally assessed ligand-dependent reaction profiles and stereoselectivities of the singlet, triplet, and quintet spin states available to the manganese species.
Immunological markers as predictors of developing steroid-induced diabetes mellitus in pemphigus vulgaris patients: An observational study.

PubMed

Dănescu, Ana Sorina; Bâldea, Ioana; Leucuţa, Daniel Corneliu; Lupan, Iulia; Samaşca, Gabriel; Sitaru, Cassian; Chiorean, Roxana; Baican, Adrian

2018-04-01

The aim of this study was to evaluate the clinical importance of autoantibodies in pemphigus vulgaris patients who developed steroid-induced diabetes mellitus (SID) because of the glucocorticoid therapy of pemphigus.A total of 137 patients with pemphigus vulgaris were studied. Patients with SID and pemphigus were compared with those that had only pemphigus. The variables recorded were: age at diagnosis, sex, body mass index, presence of diabetes mellitus (DM), cumulative cortisone dose, treatment duration, value of anti-desmoglein 1 and 3, and anti-glutamic acid decarboxylase autoantibodies.A total of 31 patients (22.62%) that developed steroid-induced DM were identified. Anti-glutamic acid decarboxylase autoantibodies were positive in 20.75% of patients with pemphigus vulgaris and in 25.75% of patients with pemphigus vulgaris and SID.The overall anti-glutamic acid decarboxylase autoantibodies prevalence in pemphigus patients was high, and the risk of developing DM in patients with pemphigus remains a serious problem, being associated with increased risk of mortality.
Production of 3-Oxo-2-(2'-pentenyl)-cyclopentane-1-octanoic Acid in the Fungus Aspergillus oryzae: A Step Towards Heterologous Production of Pyrethrins in Fungi.

PubMed

Mohamed, Maged E; Pahirulzaman, Khomaizon A K; Lazarus, Colin M

2016-03-01

Pyrethrins are natural insecticides, which accumulate to high concentrations in pyrethrum (Chrysanthemum cinerariaefolium) flowers. Synthetic pyrethroids are more stable, more efficacious and cheaper, but contemporary requirements for safe and environmentally friendly pesticides encourage a return to the use of natural pyrethrins, and this would be favoured by development of an efficient route to their production by microbial fermentation. The biosynthesis of pyrethrins involves ester linkage between an acid moiety (chrysanthemoyl or pyrethroyl, synthesised via the mevalonic acid pathway from glucose), and an alcohol (pyrethrolone). Pyrethrolone is generated from 3-oxo-2-(2'-pentenyl)-cyclopentane-1-octanoic acid, which originates from α-linolenic acid via the jasmonic acid biosynthetic cascade. The first four genes in this cascade, encoding lipoxygenase 2, allene-oxide synthase, allene-oxide cyclase 2 and 12-oxophytodienoic acid reductase 3, were amplified from an Arabidopsis thaliana cDNA library, cloned in a purpose-built fungal multigene expression vector and expressed in Aspergillus oryzae. HPLC-MS analysis of the transgenic fungus homogenate gave good evidence for the presence of 3-oxo-2-(2'-pentenyl)-cyclopentane-1-octanoic acid.
Redox and complexation chemistry of the CrVI/CrV-D-glucaric acid system.

PubMed

Mangiameli, María Florencia; González, Juan Carlos; Bellú, Sebastián; Bertoni, Fernando; Sala, Luis F

2014-06-28

When an excess of uronic acid over Cr(VI) is used, the oxidation of D-glucaric acid (Glucar) by Cr(VI) yields D-arabinaric acid, CO2 and Cr(III)-Glucar complex as final redox products. The redox reaction involves the formation of intermediate Cr(IV) and Cr(V) species. The reaction rate increases with [H(+)] and [substrate]. The experimental results indicated that Cr(IV) and Cr(V) are very reactive intermediates since their disappearance rates are much faster than Cr(VI). Cr(IV) and Cr(V) intermediates are involved in fast steps and do not accumulate in the redox reaction of the mixture Cr(VI)-Glucar. Kinetic studies show that the redox reaction between Glucar and Cr(VI) proceeds through a mechanism combining one- and two-electron pathways: Cr(VI) → Cr(IV) → Cr(II) and Cr(VI) → Cr(IV) → Cr(III). After the redox reaction, results show a slow hydrolysis of the Cr(III)-Glucar complex into [Cr(OH2)6](3+). The proposed mechanism is supported by the observation of free radicals, CrO2(2+) (superoxo-Cr(III) ion) and oxo-Cr(V)-Glucar species as reaction intermediates. The continuous-wave electron paramagnetic resonance, CW-EPR, spectra show that five-coordinate oxo-Cr(V) bischelates are formed at pH ≤ 4 with the aldaric acid bound to oxo-Cr(V) through the carboxylate and the α-OH group. A different oxo-Cr(V) species with Glucar was detected at pH 6.0. The high g(iso) value for the last species suggests a mixed coordination species, a five-coordinated oxo-Cr(V) bischelate with one molecule of Glucar acting as a bi-dentate ligand, using the 2-hydroxycarboxylate group, and a second molecule of Glucar with any vic-diolate sites. At pH 7.5 only a very weak EPR signal was observed, which may point to instability of these complexes. This behaviour contrasts with oxo-Cr(V)-uronic species, and must thus be related to the Glucar acyclic structure. In vitro, our studies on the chemistry of oxo-Cr(V)-Glucar complexes can provide information on the nature of the species that are likely to be stabilized in vivo.
Urinary biomarkers of exposure and of oxidative damage in children exposed to low airborne concentrations of benzene.

PubMed

Andreoli, R; Spatari, G; Pigini, D; Poli, D; Banda, I; Goldoni, M; Riccelli, M G; Petyx, M; Protano, C; Vitali, M; Barbaro, M; Mutti, A

2015-10-01

The aim of this work was to evaluate the oxidative damage to nucleic acids in children (5-11 years) associated with exposure to environmental pollutants and tobacco smoke (ETS). For each subject, urinary sampling was done twice (evening and next morning) to measure by tandem LC-MS-MS such oxidated products of nucleic acids as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and 8-oxo-7,8-dihydroguanine (8-oxoGua). Methyl tert-butyl ether (U-MTBE), benzene (U-Benz), and its metabolites (t,t-muconic and S-phenylmercapturic acids, t,t-MA and S-PMA, respectively) were determined as biomarkers of exposure to air pollution, and cotinine as a biomarker of exposure to ETS. Biomarkers of exposure (S-PMA and U-MTBE) and of DNA oxidation (8-oxodGuo) were dependent on the urbanization and industrialization levels and increased in the evening sample as compared to next morning (p<0.05). In both evening and next morning samples, 8-oxodGuo and 8-oxoGuo correlated with each other (r=0.596 and r=0.537, respectively, p<0.01) and with biomarkers of benzene exposure, particularly S-PMA (r=0.59 and r=0.45 for 8-oxodGuo and r=0.411 and r=0.383 for 8-oxoGuo, p<0.01). No such correlations were observed for U-MTBE and cotinine. Multiple linear regression analyses showed that 8-oxodGuo was positively associated with S-PMA at both sampling times (β=0.18 and β=0.14 for evening and next morning sampling, respectively; p<0.02) and weakly with U-MTBE (β=0.07, p=0.020) only in the evening urines. These results suggest that the selected biomarkers of exposure to benzene, particularly S-PMA, are good tracers of exposure to complex mixtures of oxidative pollutants and that the associated oxidative damage to nucleic acids is detectable even at very low levels of exposure. Copyright © 2015 Elsevier Inc. All rights reserved.
Ligand design, synthesis and biological anti-HCV evaluations for genotypes 1b and 4a of certain 4-(3- & 4-[3-(3,5-dibromo-4-hydroxyphenyl)-propylamino]phenyl) butyric acids and 3-(3,5-dibromo-4-hydroxyphenyl)-propylamino-acetamidobenzoic acid esters.

PubMed

Ismail, Mohamed Abdel Hamid; Abouzid, Khaled A M; Mohamed, Nasser Saad; Dokla, Eman Mahmoud Elawady

2013-12-01

4-(4-[N-1-carboxy-3-(3,5-dibromo-4-hydroxyphenyl)-3-oxo-propylamino]phenyl)-4-oxo-butyric acid (V), 4-(3- & 4-[N-1-carboxy-3-(3,5-dibromo-4-hydroxyphenyl)-3-oxo-propylaminophenyl]-2-aryl-4-oxo-butyric acids (Xa-e) and 4-(2-alkyl-2-[N-3-(3,5-dibromo-4-hydroxyphenyl)-1-carboxy-3-oxo-propylamino]acetamido) benzoate esters (XVa-e) were designed, synthesized and biologically evaluated as anti-HCV for genotypes 1b and 4a. The design was based on their docking scores with HCV NS3/4A protease-binding site of the genotype 1b (1W3C), which is conserved in the genotype 4a structure. The docking scores predicted that most of these molecules have higher affinity to the HCV NS3/4A enzyme more than Indoline lead. These compounds were synthesized and evaluated for their cytopathic inhibitory activity against RAW HCV cell cultures of genotype 4a and also examined against Huh 5-2 HCV cell culture of genotype 1b, utilizing Luciferase and MTS assays. Compounds Xa and Xb have 95 and 80% of the activity of Ribavirin against genotype 4a and compounds XVa, XVb and XVd exerted high percentage inhibitory activity against genotype 1b equal 87.7, 84.3 and 82.8%, respectively, with low EC50 doses.
Immunopathology of autoantibody-associated encephalitides: clues for pathogenesis.

PubMed

Bien, Christian G; Vincent, Angela; Barnett, Michael H; Becker, Albert J; Blümcke, Ingmar; Graus, Francesc; Jellinger, Kurt A; Reuss, David E; Ribalta, Teresa; Schlegel, Jürgen; Sutton, Ian; Lassmann, Hans; Bauer, Jan

2012-05-01

Classical paraneoplastic encephalitis syndromes with 'onconeural' antibodies directed to intracellular antigens, and the recently described paraneoplastic or non-paraneoplastic encephalitides and antibodies against both neural surface antigens (voltage-gated potassium channel-complexes, N-methyl-d-aspartate receptors) and intracellular antigens (glutamic acid decarboxylase-65), constitute an increasingly recognized group of immune-mediated brain diseases. Evidence for specific immune mechanisms, however, is scarce. Here, we report qualitative and quantitative immunopathology in brain tissue (biopsy or autopsy material) of 17 cases with encephalitis and antibodies to either intracellular (Hu, Ma2, glutamic acid decarboxylase) or surface antigenic targets (voltage-gated potassium channel-complex or N-methyl-d-aspartate receptors). We hypothesized that the encephalitides with antibodies against intracellular antigens (intracellular antigen-onconeural and intracellular antigen-glutamic acid decarboxylase groups) would show neurodegeneration mediated by T cell cytotoxicity and the encephalitides with antibodies against surface antigens would be antibody-mediated and would show less T cell involvement. We found a higher CD8/CD3 ratio and more frequent appositions of granzyme-B(+) cytotoxic T cells to neurons, with associated neuronal loss, in the intracellular antigen-onconeural group (anti-Hu and anti-Ma2 cases) compared to the patients with surface antigens (anti-N-methyl-d-aspartate receptors and anti-voltage-gated potassium channel complex cases). One of the glutamic acid decarboxylase antibody encephalitis cases (intracellular antigen-glutamic acid decarboxylase group) showed multiple appositions of GrB-positive T cells to neurons. Generally, however, the glutamic acid decarboxylase antibody cases showed less intense inflammation and also had relatively low CD8/CD3 ratios compared with the intracellular antigen-onconeural cases. Conversely, we found complement C9neo deposition on neurons associated with acute neuronal cell death in the surface antigen group only, specifically in the voltage-gated potassium channel-complex antibody patients. N-methyl-d-aspartate receptors-antibody cases showed no evidence of antibody and complement-mediated tissue injury and were distinguished from all other encephalitides by the absence of clear neuronal pathology and a low density of inflammatory cells. Although tissue samples varied in location and in the stage of disease, our findings strongly support a central role for T cell-mediated neuronal cytotoxicity in encephalitides with antibodies against intracellular antigens. In voltage-gated potassium channel-complex encephalitis, a subset of the surface antigen antibody encephalitides, an antibody- and complement-mediated immune response appears to be responsible for neuronal loss and cerebral atrophy; the apparent absence of these mechanisms in N-methyl-d-aspartate receptors antibody encephalitis is intriguing and requires further study.
Identification of 9α-Hydroxy-17-Oxo-1,2,3,4,10,19-Hexanorandrostan-5-Oic Acid in Steroid Degradation by Comamonas testosteroni TA441 and Its Conversion to the Corresponding 6-En-5-Oyl Coenzyme A (CoA) Involving Open Reading Frame 28 (ORF28)- and ORF30-Encoded Acyl-CoA Dehydrogenases

PubMed Central

Hayashi, Toshiaki; Koshino, Hiroyuki; Malon, Michal; Hirota, Hiroshi; Kudo, Toshiaki

2014-01-01

Comamonas testosteroni TA441 degrades steroids via aromatization and meta-cleavage of the A ring, followed by hydrolysis, and produces 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid as an intermediate compound. Herein, we identify a new intermediate compound, 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid. Open reading frame 28 (ORF28)- and ORF30-encoded acyl coenzyme A (acyl-CoA) dehydrogenase was shown to convert the CoA ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid to the CoA ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrost-6-en-5-oic acid. A homology search of the deduced amino acid sequences suggested that the ORF30-encoded protein is a member of the acyl-CoA dehydrogenase_fadE6_17_26 family, whereas the deduced amino acid sequence of ORF28 showed no significant similarity to specific acyl-CoA dehydrogenase family proteins. Possible steroid degradation gene clusters similar to the cluster of TA441 appear in bacterial genome analysis data. In these clusters, ORFs similar to ORFs 28 and 30 are often found side by side and ordered in the same manner as ORFs 28 and 30. PMID:25092028
Gabapentin-base synthesis and theoretical studies of biologically active compounds: N-cyclohexyl-3-oxo-2-(3-oxo-2-azaspiro[4.5] decan-2-yl)-3-arylpropanamides and N-(tert-butyl)-2-(3-oxo-2-azaspiro[4.5]decan-2-yl)-2-arylacetamide derivatives

NASA Astrophysics Data System (ADS)

Amirani Poor, Mahboobe; Darehkordi, Ali; Anary-Abbasinejad, Mohammad; Mohammadi, Marziyeh

2018-01-01

An intermolecular Ugi reaction of 2-(1-(aminomethyl)cyclohexyl)acetic acid (gabapentin) with glyoxal and cyclohexyl isocyanide or aromatic aldehyde and tertbutyl isocyanide under mild conditions in ethanol have been developed to produce two novel class of N-cyclohexyl-3-(aryl)-3-oxo-2-(3-oxo-2-azaspiro[4.5]decan-2-yl)propanamideins and N-(tert-butyl)-2-(3-oxo-2-azaspiro[4.5]decan-2-yl)-2-arylacetamide derivatives in good to excellent yields. This presents the first report for the intermolecular Ugi three component reaction of gabapentin, glyoxal, and an isocyanide. Also according to the theoretical studies the electron-donating groups increase the strength of intramolecular hydrogen bond and electron-withdrawing groups decrease the strength of intramolecular hydrogen bond.
[Studies on chemical constituents from herbs of Taraxacum mongolicum].

PubMed

Shi, Shu-Yun; Zhou, Chang-Xin; Xu, Yan; Tao, Qiao-Feng; Bai, Hua; Lu, Fu-Sheng; Lin, Wen-Yan; Chen, Hai-Yong; Zheng, Wei; Wang, Li-Wei; Wu, Yi-Hang; Zeng, Su; Huang, Ke-Xin; Zhao, Yu; Li, Xiao-Kun; Qu, Jia

2008-05-01

To investigate the chemical constituents of the herbs of Taraxacum mongolicum. The chemical constituents were isolated by various column chromatographic methods and their structures elucidated mainly by NMR and MS evidences. Forty-four components were obtained and identified were as artemetin (1), quercetin (2), quercetin-3', 4', 7-trime-thyl ether (3), luteolin (4), luteolin-7-O-beta-D-glucopyranoside (5), luteolin-7-O-beta-D-galactopyranoside (6), genkwanin (7), isoetin (8), hesperetin (9), genkwanin-4'-O-beta-D-lutinoside (10), hesperidin (11), quercetin-7-O-[beta-D-glucopyranosyl (1-->6) -beta-D-glucopyranoside (12), quercetin-3, 7-O-beta-D-diglucopyranoside (13), isoetin-7-O-beta-D-glucopyranosyl- 2'-O-alpha-L-arabinopyranoside (14), isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-D-glucopyranoside (15), isoetin-7- O-beta-D-glucopyranosyl-2'-O-beta-D-xyloypyranoside (16), caffeic acid (17), furulic acid (18), 3-O-caffeoylquinic acid (19), 3, 5-di-O-caffeoylquinic acid (20), 3, 4-di-O-caffeoylquinic acid (21), 4, 5-di-O-caffeoylquinic acid (22), 1-hydroxymethyl-5-hydroxy-phenyl-2-O-beta-D-glucopyranoside (23), p-hydroxybenzoic acid (24), p-coumaric acid (25), 3, 5-dihydroxylbenzoic acid (26), gallic acid (27), gallicin (28), syringic acid (29), 3, 4-dihydroxybenzoic acid (30), caffeic acid ethyl ester (31), esculetin (32), rufescidride (33), mongolicumin A [6, 9, 10-trihydroxy-benzoxanthene-1, 2-dicarboxylic acid] (34), mongolicumin B [1 l-hydroxy-2-oxo-guaia-1 (10), 3, 5-trien-8, 12-lactone] (35), isodonsesquitin A (36), taraxacin (37), sesquiterpene ketolactone (38), taraxasteryl acetate (39), phi-taraxasteryl acetate (40) and lupenol acetate (41), palmitic acid (42), beta-sitosterol (43), and stigmasterol (44). Four compounds (14, 15, 34 and 35) were new compounds, compounds 1, 3, 6-13, 20-22, 30 and 31 were isolated from this genus for the first time, while compounds 18, 23-29, 32 and 37-42 were obtained from this species for the first time.

Androstanes and pregnanes from Trichilia emetica ssp. suberosa J.J. de Wilde.

PubMed

Malafronte, Nicola; Sanogo, Rokia; Vassallo, Antonio; De Tommasi, Nunziatina; Bifulco, Giuseppe; Dal Piaz, Fabrizio

2013-12-01

Four pregnanes: 1-methoxy-pregnan-17(R)-1,4-dien-3,16-dione (1), 1-methoxy-pregnan-17(S)-1,4-dien-3,16-dione (2), 2,3-seco-pregnan-17(S)-2,3-dioic acid-16-oxo-dimethyl ester (4), 2α,3α,16α-trihydroxy-5α-pregnan-17(R)-20-yl acetate (7), three androstanes: 1-methoxy-androstan-1,4-dien-3,16-dione (3), 2,3-seco-androstan-2,3-dioic acid-16-oxo-dimethyl ester (5), 3-methoxycarbonyl-2,3-seco-androstan-3-oic acid-16-oxo-2,19-lactone (6), together with three known pregnane derivatives, were isolated from the roots of Trichilia emetica ssp. suberosa. Their structures were determined by means of 1D and 2D NMR spectroscopy, mass spectrometry analysis, as well as by quantum chemical calculations. Copyright © 2013 Elsevier Ltd. All rights reserved.
Clarithromycin, trimethoprim, and penicillin and oxidative nucleic acid modifications in humans: randomised, controlled trials.

PubMed

Larsen, Emil List; Cejvanovic, Vanja; Kjaer, Laura Kofoed; Pedersen, Morten Thorup; Popik, Sara Daugaard; Hansen, Lina Kallehave; Andersen, Jon Traerup; Jimenez-Solem, Espen; Broedbaek, Kasper; Petersen, Morten; Weimann, Allan; Henriksen, Trine; Lykkesfeldt, Jens; Torp-Pedersen, Christian; Poulsen, Henrik Enghusen

2017-08-01

In vitro studies have demonstrated that formation of reactive oxygen species (ROS) contributes to the effect of bactericidal antibiotics. The formation of ROS is not restricted to bacteria, but also occurs in mammalian cells. Oxidative stress is linked to several diseases. This study investigates whether antibiotic drugs induce oxidative stress in healthy humans as a possible mechanism for adverse reactions to the antibiotic drugs. This study contains information from two randomised, controlled trials. Participants underwent 1 week treatment with clarithromycin, trimethoprim, phenoxymethylpenicillin (penicillin V), or placebo. Oxidative modifications were measured as 24-h urinary excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and plasma levels of malondialdehyde before and after treatment as a measurement of DNA oxidation, RNA oxidation, and lipid peroxidation, respectively. Clarithromycin significantly increased urinary excretion of 8-oxodG by 22.0% (95% confidence interval (CI): 3.6-40.4%) and 8-oxoGuo by 14.9% (95% CI: 3.7-26.1%). Further, we demonstrated that trimethoprim significantly lowered urinary excretion of 8-oxodG by 21.7% (95% CI: 5.8-37.6%), but did not influence urinary excretion of 8-oxoGuo. Penicillin V did not influence urinary excretion of 8-oxodG or 8-oxoGuo. None of the antibiotic drugs influenced plasma levels of malondialdehyde. Clarithromycin significantly increases oxidative nucleic acid modifications. Increased oxidative modifications might explain some of clarithromycin's known adverse reactions. Trimethoprim significantly lowers DNA oxidation but not RNA oxidation. Penicillin V had no effect on oxidative nucleic acid modifications. © 2017 The British Pharmacological Society.
Overexpression, purification, crystallization and preliminary structural studies of p-coumaric acid decarboxylase from Lactobacillus plantarum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodríguez, Héctor; Rivas, Blanca de las; Muñoz, Rosario

2007-04-01

The enzyme p-coumaric acid decarboxylase (PDC) from L. plantarum has been recombinantly expressed, purified and crystallized. The structure has been solved at 2.04 Å resolution by the molecular-replacement method. The substrate-inducible p-coumaric acid decarboxylase (PDC) from Lactobacillus plantarum has been overexpressed in Escherichia coli, purified and confirmed to possess decarboxylase activity. The recombinant His{sub 6}-tagged enzyme was crystallized using the hanging-drop vapour-diffusion method from a solution containing 20%(w/v) PEG 4000, 12%(w/v) 2-propanol, 0.2 M sodium acetate, 0.1 M Tris–HCl pH 8.0 with 0.1 M barium chloride as an additive. Diffraction data were collected in-house to 2.04 Å resolution. Crystals belongedmore » to the tetragonal space group P4{sub 3}, with unit-cell parameters a = b = 43.15, c = 231.86 Å. The estimated Matthews coefficient was 2.36 Å{sup 3} Da{sup −1}, corresponding to 48% solvent content, which is consistent with the presence of two protein molecules in the asymmetric unit. The structure of PDC has been determined by the molecular-replacement method. Currently, the structure of PDC complexed with substrate analogues is in progress, with the aim of elucidating the structural basis of the catalytic mechanism.« less
Polyamine formation by arginine decarboxylase as a transducer of hormonal, environmental and stress stimuli in higher plants

NASA Technical Reports Server (NTRS)

Galston, A. W.; Flores, H. E.; Kaur-Sawhney, R.

1982-01-01

Recent evidence implicates polyamines including putrescine in the regulation of such diverse plant processes as cell division, embryogenesis and senescence. We find that the enzyme arginine decarboxylase, which controls the rate of putrescine formation in some plant systems, is activated by light acting through P(r) phytochrome as a receptor, by the plant hormone gibberellic acid, by osmotic shock and by other stress stimuli. We therefore propose arginine decarboxylase as a possible transducer of the various initially received tropistic stimuli in plants. The putrescine formed could act by affecting cytoskeletal components.
Production of biogenic amines by lactic acid bacteria and enterobacteria isolated from fresh pork sausages packaged in different atmospheres and kept under refrigeration.

PubMed

Curiel, J A; Ruiz-Capillas, C; de Las Rivas, B; Carrascosa, A V; Jiménez-Colmenero, F; Muñoz, R

2011-07-01

The occurrence of in vitro amino acid activity in bacterial strains associated with fresh pork sausages packaged in different atmospheres and kept in refrigeration was studied. The presence of biogenic amines in decarboxylase broth was confirmed by ion-exchange chromatography and by the presence of the corresponding decarboxylase genes by PCR. From the 93 lactic acid bacteria and 100 enterobacteria strains analysed, the decarboxylase medium underestimates the number of biogenic amine-producer strains. 28% of the lactic acid bacteria produced tyramine and presented the tdc gene. All the tyramine-producer strains were molecularly identified as Carnobacterium divergens. Differences on the relative abundance of C. divergens were observed among the different packaging atmospheres assayed. After 28 days of storage, the presence of argon seems to inhibit C. divergens growth, while packing under vacuum seems to favour it. Among enterobacteria, putrescine was the amine more frequently produced (87%), followed by cadaverine (85%); agmatine and tyramine were only produced by 13 and 1%, respectively, of the strains analysed. Packing under vacuum or in an atmosphere containing nitrogen seems to inhibit the growth of enterobacteria which produce simultaneously putrescine, cadaverine, and agmatine. Contrarily, over-wrapping or packing in an atmosphere containing argon seems to favour the growth of agmatine producer-enterobacteria. The production of putrescine and cadaverine was associated with the presence of the corresponding amino acid decarboxylase genes. The biogenic amine-producer strains were included in a wide range of enterobacterial species, including Kluyvera intermedia, Enterobacter aerogenes, Yersinia kristensenii, Serratia grimesii, Serratia ficaria, Yersinia rodhei, Providencia vermicola and Obesumbacterium proteus. Copyright © 2011 Elsevier Ltd. All rights reserved.
Contribution of glutamate decarboxylase in Lactobacillus reuteri to acid resistance and persistence in sourdough fermentation

PubMed Central

2011-01-01

Background Acid stress impacts the persistence of lactobacilli in industrial sourdough fermentations, and in intestinal ecosystems. However, the contribution of glutamate to acid resistance in lactobacilli has not been demonstrated experimentally, and evidence for the contribution of acid resistance to the competitiveness of lactobacilli in sourdough is lacking. It was therefore the aim of this study to investigate the ecological role of glutamate decarboxylase in L. reuteri. Results A gene coding for a putative glutamate decarboxylase, gadB, was identified in the genome of L. reuteri 100-23. Different from the organization of genetic loci coding for glutamate decarboxylase in other lactic acid bacteria, gadB was located adjacent to a putative glutaminase gene, gls3. An isogenic deletion mutant, L. reuteri ∆gadB, was generated by a double crossover method. L. reuteri 100-23 but not L. reuteri ∆gadB converted glutamate to γ-aminobutyrate (GABA) in phosphate butter (pH 2.5). In sourdough, both strains converted glutamine to glutamate but only L. reuteri 100-23 accumulated GABA. Glutamate addition to phosphate buffer, pH 2.5, improved survival of L. reuteri 100-23 100-fold. However, survival of L. reuteri ∆gadB remained essentially unchanged. The disruption of gadB did not affect growth of L. reuteri in mMRS or in sourdough. However, the wild type strain L. reuteri 100-23 displaced L. reuteri ∆gadB after 5 cycles of fermentation in back-slopped sourdough fermentations. Conclusions The conversion of glutamate to GABA by L. reuteri 100-23 contributes to acid resistance and to competitiveness in industrial sourdough fermentations. The organization of the gene cluster for glutamate conversion, and the availability of amino acids in cereals imply that glutamine rather than glutamate functions as the substrate for GABA formation. The exceptional coupling of glutamine deamidation to glutamate decarboxylation in L.Â reuteri likely reflects adaptation to cereal substrates. PMID:21995488
Metabolism of Linoleic Acid by Barley Lipoxygenase and Hydroperoxide Isomerase 1

PubMed Central

Lulai, Edward C.; Baker, Charles W.; Zimmerman, Don C.

1981-01-01

The oxidation of linoleic acid in incubation mixtures containing extracts of barley lipoxygenase and hydroperoxide isomerase, and the production of these enzymes in quiescent and germinated barley, were investigated. The ratio of 9-hydroperoxylinoleic acid to 13-hydroperoxylinoleic acid was higher for incubation mixtures containing extracts of quiescent barley than for mixtures containing extracts of germinated barley; production of 13-hydroperoxylinoleic acid from germinated barley exceeded that of quiescent barley. Hydroperoxy metabolites of linoleic acid were converted to 9-hydroxy-10-oxo-cis-12-octadecenoic acid, 13-hydroxy-10-oxo-trans-11-octadecenoic acid, and small amounts of 11-hydroxy-12,13-epoxy-cis-9-octadecenoic acid and 11-hydroxy-9,10-epoxy-cis-13-octadecenoic acid whether quiescent or germinated barley was the enzyme source; a fifth product, 13-hydroxy-12-oxo-cis-9-octadecenoic acid was formed only when germinated barley was the enzyme source. Lipoxygenase was readily extracted by buffer, but hydroperoxide isomerase was bound in a catalytically active state to the insoluble barley grist and was efficiently extracted only when Triton X-100 was included in the extraction buffer. Hydroperoxide isomerase was localized in the embryo of quiescent barley, but it was present in the embryo, acrospire, and in small but concentrated amounts in the rootlet of germinating barley. The levels of both lipoxygenase and hydroperoxide isomerase increased through the thirteenth day of germination. Images PMID:16662032
Structural basis of enzymatic activity for the ferulic acid decarboxylase (FADase) from Enterobacter sp. Px6-4.

PubMed

Gu, Wen; Yang, Jinkui; Lou, Zhiyong; Liang, Lianming; Sun, Yuna; Huang, Jingwen; Li, Xuemei; Cao, Yi; Meng, Zhaohui; Zhang, Ke-Qin

2011-01-21

Microbial ferulic acid decarboxylase (FADase) catalyzes the transformation of ferulic acid to 4-hydroxy-3-methoxystyrene (4-vinylguaiacol) via non-oxidative decarboxylation. Here we report the crystal structures of the Enterobacter sp. Px6-4 FADase and the enzyme in complex with substrate analogues. Our analyses revealed that FADase possessed a half-opened bottom β-barrel with the catalytic pocket located between the middle of the core β-barrel and the helical bottom. Its structure shared a high degree of similarity with members of the phenolic acid decarboxylase (PAD) superfamily. Structural analysis revealed that FADase catalyzed reactions by an "open-closed" mechanism involving a pocket of 8 × 8 × 15 Å dimension on the surface of the enzyme. The active pocket could directly contact the solvent and allow the substrate to enter when induced by substrate analogues. Site-directed mutagenesis showed that the E134A mutation decreased the enzyme activity by more than 60%, and Y21A and Y27A mutations abolished the enzyme activity completely. The combined structural and mutagenesis results suggest that during decarboxylation of ferulic acid by FADase, Trp25 and Tyr27 are required for the entering and proper orientation of the substrate while Glu134 and Asn23 participate in proton transfer.
Engaging the Terminal: Promoting Halogen Bonding Interactions with Uranyl Oxo Atoms.

PubMed

Carter, Korey P; Kalaj, Mark; Surbella, Robert G; Ducati, Lucas C; Autschbach, Jochen; Cahill, Christopher L

2017-11-02

Engaging the nominally terminal oxo atoms of the linear uranyl (UO 2 2+ ) cation in non-covalent interactions represents both a significant challenge and opportunity within the field of actinide hybrid materials. An approach has been developed for promoting oxo atom participation in a range of non-covalent interactions, through judicious choice of electron donating equatorial ligands and appropriately polarizable halogen-donor atoms. As such, a family of uranyl hybrid materials was generated based on a combination of 2,5-dihalobenzoic acid and aromatic, chelating N-donor ligands. Delineation of criteria for oxo participation in halogen bonding interactions has been achieved by preparing materials containing 2,5-dichloro- (25diClBA) and 2,5-dibromobenzoic acid (25diBrBA) coupled with 2,2'-bipyridine (bipy) (1 and 2), 1,10-phenanthroline (phen) (3-5), 2,2':6',2''-terpyridine (terpy) (6-8), or 4'-chloro-2,2':6',2''-terpyridine (Cl-terpy) (9-10), which have been characterized through single crystal X-ray diffraction, Raman, Infrared (IR), and luminescence spectroscopy, as well as through density functional calculations of electrostatic potentials. Looking comprehensively, these results are compared with recently published analogues featuring 2,5-diiodobenzoic acid which indicate that although inclusion of a capping ligand in the uranyl first coordination sphere is important, it is the polarizability of the selected halogen atom that ultimately drives halogen bonding interactions with the uranyl oxo atoms. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Copper resinate: preparation, characterisation and study of degradation.

PubMed

Colombini, M P; Lanterna, G; Mairani, A; Matteini, M; Modugno, F; Rizzi, M

2001-01-01

This paper describes a method for the synthesis of Copper Resinate, which disappeared from artists' palettes in the eighteenth century. This was carried out by interpreting ancient recipes following a scientific approach. Its characterisation using Fourier Transform-Infrared Spectrometry and Gas Chromatography-Mass Spectrometry demonstrated that it is a mixture containing copper and oxidised abietic acids, mainly dehydroabietic and 7-oxo-dehydroabietic acids, formed during the preparation of the pigment and the curing of the paint layer. The composition of copper resinate paint layers, artificially aged by U.V. irradiation at 365 nm (UV), heating (T), and exposed to atmospheric pollutants (NOX) in a climatic chamber, was investigated. The combination of irradiation and temperature produced a change in colour along with a significant increase in the recovered amount of 7-oxo-dehydroabietic acid. The identification of copper resinate in a sample from an old painting should be related to the presence of the following resin compounds which are stable in the ageing process: dehydroabietic and 7-oxo-dehydroabietic acid pimaradienic acids. Photo-oxidation of the resin acids co-ordinated with copper seem to be the most probable decay mechanism responsible for the colour change in the pigment.
Effects of polyamine biosynthesis inhibitors on S-adenosylmethionine synthetase and S-adenosylmethionine decarboxylase activities in carrot cell cultures

Treesearch

S.C. Minocha; R. Minocha; A. Komamine

1991-01-01

Changes in the activites of S-adcnosylmethionine (SAM) synthetase (methionine adenosyltransferase, EC 2.5.1.6.) and SAM decarboxylase (EC 4.1.1.50) were studied in carrot (Daucus carota) cell cultures in response to 2,4-dichlorophenoxyacetic acid (2,4-D) and several inhibitors of polyamine biosynthesis. Activity of SAM synthetase increased...
Experimental Evidence and In Silico Identification of Tryptophan Decarboxylase in Citrus Genus.

PubMed

De Masi, Luigi; Castaldo, Domenico; Pignone, Domenico; Servillo, Luigi; Facchiano, Angelo

2017-02-11

Plant tryptophan decarboxylase (TDC) converts tryptophan into tryptamine, precursor of indolealkylamine alkaloids. The recent finding of tryptamine metabolites in Citrus plants leads to hypothesize the existence of TDC activity in this genus. Here, we report for the first time that, in Citrus x limon seedlings, deuterium labeled tryptophan is decarboxylated into tryptamine, from which successively deuterated N , N , N -trimethyltryptamine is formed. These results give an evidence of the occurrence of the TDC activity and the successive methylation pathway of the tryptamine produced from the tryptophan decarboxylation. In addition, with the aim to identify the genetic basis for the presence of TDC, we carried out a sequence similarity search for TDC in the Citrus genomes using as a probe the TDC sequence reported for the plant Catharanthus roseus . We analyzed the genomes of both Citrus clementina and Citrus sinensis , available in public database, and identified putative protein sequences of aromatic l-amino acid decarboxylase. Similarly, 42 aromatic l-amino acid decarboxylase sequences from 23 plant species were extracted from public databases. Potential sequence signatures for functional TDC were then identified. With this research, we propose for the first time a putative protein sequence for TDC in the genus Citrus .
The activity state of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.

PubMed Central

Wagenmakers, A J; Schepens, J T; Veldhuizen, J A; Veerkamp, J H

1984-01-01

An assay is described to define the proportion of the branched-chain 2-oxo acid dehydrogenase complex that is present in the active state in rat tissues. Activities are measured in homogenates in two ways: actual activities, present in tissues, by blocking both the kinase and phosphatase of the enzyme complex during homogenization, preincubation, and incubation with 1-14C-labelled branched-chain 2-oxo acid, and total activities by blocking only the kinase during the 5 min preincubation (necessary for activation). The kinase is blocked by 5 mM-ADP and absence of Mg2+ and the phosphatase by the simultaneous presence of 50 mM-NaF. About 6% of the enzyme is active in skeletal muscle of fed rats, 7% in heart, 20% in diaphragm, 47% in kidney, 60% in brain and 98% in liver. An entirely different assay, which measures activities in crude tissue extracts before and after treatment with a broad-specificity protein phosphatase, gave similar results for heart, liver and kidney. Advantages of our assay with homogenates are the presence of intact mitochondria, the simplicity, the short duration and the high sensitivity. The actual activities measured indicate that the degradation of branched-chain 2-oxo acids predominantly occurs in liver and kidney and is limited in skeletal muscle in the fed state. PMID:6430280
The activity state of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.

PubMed

Wagenmakers, A J; Schepens, J T; Veldhuizen, J A; Veerkamp, J H

1984-05-15

An assay is described to define the proportion of the branched-chain 2-oxo acid dehydrogenase complex that is present in the active state in rat tissues. Activities are measured in homogenates in two ways: actual activities, present in tissues, by blocking both the kinase and phosphatase of the enzyme complex during homogenization, preincubation, and incubation with 1-14C-labelled branched-chain 2-oxo acid, and total activities by blocking only the kinase during the 5 min preincubation (necessary for activation). The kinase is blocked by 5 mM-ADP and absence of Mg2+ and the phosphatase by the simultaneous presence of 50 mM-NaF. About 6% of the enzyme is active in skeletal muscle of fed rats, 7% in heart, 20% in diaphragm, 47% in kidney, 60% in brain and 98% in liver. An entirely different assay, which measures activities in crude tissue extracts before and after treatment with a broad-specificity protein phosphatase, gave similar results for heart, liver and kidney. Advantages of our assay with homogenates are the presence of intact mitochondria, the simplicity, the short duration and the high sensitivity. The actual activities measured indicate that the degradation of branched-chain 2-oxo acids predominantly occurs in liver and kidney and is limited in skeletal muscle in the fed state.
Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins.

PubMed Central

Lindqvist, Y; Huang, W; Schneider, G; Shanklin, J

1996-01-01

The three-dimensional structure of recombinant homodimeric delta9 stearoyl-acyl carrier protein desaturase, the archetype of the soluble plant fatty acid desaturases that convert saturated to unsaturated fatty acids, has been determined by protein crystallographic methods to a resolution of 2.4 angstroms. The structure was solved by a combination of single isomorphous replacement, anomalous contribution from the iron atoms to the native diffraction data and 6-fold non-crystallographic symmetry averaging. The 363 amino acid monomer consists of a single domain of 11 alpha-helices. Nine of these form an antiparallel helix bundle. The enzyme subunit contains a di-iron centre, with ligands from four of the alpha-helices in the helix bundle. The iron ions are bound in a highly symmetric environment, with one of the irons forming interactions with the side chains of E196 and H232 and the second iron with the side chains of E105 and H146. Two additional glutamic acid side chains, from E143 and E229, are within coordination distance to both iron ions. A water molecule is found within the second coordination sphere from the iron atoms. The lack of electron density corresponding to a mu-oxo bridge, and the long (4.2 angstroms) distance between the iron ions suggests that this probably represents the diferrous form of the enzyme. A deep channel which probably binds the fatty acid extends from the surface into the interior of the enzyme. Modelling of the substrate, stearic acid, into this channel places the delta9 carbon atom in the vicinity of one of the iron ions. Images PMID:8861937
Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins.

PubMed

Lindqvist, Y; Huang, W; Schneider, G; Shanklin, J

1996-08-15

The three-dimensional structure of recombinant homodimeric delta9 stearoyl-acyl carrier protein desaturase, the archetype of the soluble plant fatty acid desaturases that convert saturated to unsaturated fatty acids, has been determined by protein crystallographic methods to a resolution of 2.4 angstroms. The structure was solved by a combination of single isomorphous replacement, anomalous contribution from the iron atoms to the native diffraction data and 6-fold non-crystallographic symmetry averaging. The 363 amino acid monomer consists of a single domain of 11 alpha-helices. Nine of these form an antiparallel helix bundle. The enzyme subunit contains a di-iron centre, with ligands from four of the alpha-helices in the helix bundle. The iron ions are bound in a highly symmetric environment, with one of the irons forming interactions with the side chains of E196 and H232 and the second iron with the side chains of E105 and H146. Two additional glutamic acid side chains, from E143 and E229, are within coordination distance to both iron ions. A water molecule is found within the second coordination sphere from the iron atoms. The lack of electron density corresponding to a mu-oxo bridge, and the long (4.2 angstroms) distance between the iron ions suggests that this probably represents the diferrous form of the enzyme. A deep channel which probably binds the fatty acid extends from the surface into the interior of the enzyme. Modelling of the substrate, stearic acid, into this channel places the delta9 carbon atom in the vicinity of one of the iron ions.
Synthesis, structures, electrochemical studies and antioxidant activity of 5-aryl-4-oxo-3,4,5,8-tetrahydropyrido[2,3-d]pyrimidine-7-carboxylic acids

NASA Astrophysics Data System (ADS)

Quiroga, Jairo; Romo, Pablo E.; Ortiz, Alejandro; Isaza, José Hipólito; Insuasty, Braulio; Abonia, Rodrigo; Nogueras, Manuel; Cobo, Justo

2016-09-01

The synthesis of 5-aryl-4-oxo-3,4,5,8-tetrahydropyrido[2,3-d]pyrimidine-7-carboxylic acids 3 from the reaction of 6-aminopyrimidines 1 with arylidene derivatives of pyruvic acid 2 under microwave and ultrasound irradiation is described. The orientation of cyclization process was determined by NMR measurements. The methodology provides advantages such as high yields and friendly to the environment without the use of solvents. The antioxidant properties, DPPH free radical scavenging, ORAC, and anodic potential oxidation of the new pyridopyrimidines were studied.
Vascular trauma and prostacyclin release.

PubMed

Jeremy, J Y; Mikhailidis, D P; Dandona, P

1984-10-01

The effect of trauma on prostacyclin (PGI2) secretion by rat aorta was examined. Whereas cutting and puncturing markedly increased PGI2 secretion, sonication and stretch had no effect. Cutting and puncturing were also effective in stimulating further endogenous secretion of PGI2 from 'exhausted' aortic segments in whom PGI2 production had dwindled to a negligible rate. These experiments show that trauma is an important stimulator of PGI2 secretion, the exhaustion of PGI2 secretion by vascular segments is not due to the depletion of substrate (arachidonic acid) and that an unusually traumatic venepuncture may invalidate the subsequent assays of PGI2 and its stable metabolite, 6-oxo-PGF1 alpha, in plasma. The close relationship of vascular trauma to PGI2 release also suggests a possible cytoprotective effect of this prostanoid on vascular endothelium.
Purification and preliminary characterization of (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid synthase, an enzyme involved in biosynthesis of the antitumor agent sparsomycin.

PubMed

Parry, R J; Hoyt, J C

1997-02-01

Sparsomycin is an antitumor antibiotic produced by Streptomyces sparsogenes. Biosynthetic experiments have previously demonstrated that one component of sparsomycin is derived from L-tryptophan via the intermediacy of (E)-3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid and (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid. An enzyme which catalyzes the conversion of (E)-3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid to (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid has been purified 740-fold to homogeneity from S. sparsogenes. The molecular mass of the native and denatured enzyme was 87 kDa, indicating that the native enzyme is monomeric. The enzyme required NAD+ for activity but lacked rigid substrate specificity, since analogs of both NAD+ and 3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid could serve as substrates. The enzyme was very weakly inhibited by mycophenolic acid. Monovalent cations were required for activity, with potassium ions being the most effective. The enzyme exhibited sensitivity toward diethylpyrocarbonate and some thiol-directed reagents, and it was irreversibly inhibited by 6-chloropurine. The properties of the enzyme suggest it is mechanistically related to inosine-5'-monophosphate dehydrogenase.
Bioinspired catalytic generation of high-valent cobalt-oxo species by the axially coordinated CoPc on pyridine-functionalized MWCNTs for the elimination of organic contaminants

NASA Astrophysics Data System (ADS)

Li, Nan; Wang, Ying; Wu, Chenren; Lu, Wangyang; Pei, Kemei; Chen, Wenxing

2018-03-01

Enzymes have always been a source of inspiration for the design and improvement of catalysts. Many examples are occurring in heme/non-heme metalloenzymes with the generation of active high-valent metal-oxo intermediates that are controlled by the surrounding amino acids/protein and axial residue ligands, facilitating the efficient oxidation of substrates in biochemical processes. Here, the high-valent cobalt-oxo species have been formed during the heterolysis of H2O2 activated by the bioinspired catalyst, axially coordinated cobalt phthalocyanine (CoPc) on pyridine-functionalized multi-walled carbon nanotubes (MWCNTs-Py), characterized by ultraviolet-visible and X-ray photoelectron spectroscopy. Formation process of the active cobalt-oxo species has been further confirmed by electrospray ionization mass spectrometry analysis and the results from the density functional theory (B3LYP/6-311G) calculations. Such high-valent cobalt-oxo species exhibit high reactivity and enough persistence for the oxidation of the target substrate, C.I. Acid Red 1. The oxidation products are nearly biodegradable small molecules identified by ultra-performance liquid chromatography/high-definition mass spectrometry. This strategy provides a foundation on developing efficient and persistent catalytic system, in particular oxidation processes based on the complex catalysts with N4 macrocycle structures.

Characterization of the cDNA coding for rat brain cysteine sulfinate decarboxylase: brain and liver enzymes are identical proteins encoded by two distinct mRNAs.

PubMed

Tappaz, M; Bitoun, M; Reymond, I; Sergeant, A

1999-09-01

Cysteine sulfinate decarboxylase (CSD) is considered as the rate-limiting enzyme in the biosynthesis of taurine, a possible osmoregulator in brain. Through cloning and sequencing of RT-PCR and RACE-PCR products of rat brain mRNAs, a 2,396-bp cDNA sequence was obtained encoding a protein of 493 amino acids (calculated molecular mass, 55.2 kDa). The corresponding fusion protein showed a substrate specificity similar to that of the endogenous enzyme. The sequence of the encoded protein is identical to that encoded by liver CSD cDNA. Among other characterized amino acid decarboxylases, CSD shows the highest homology (54%) with either isoform of glutamic acid decarboxylase (GAD65 and GAD67). A single mRNA band, approximately 2.5 kb, was detected by northern blot in RNA extracts of brain, liver, and kidney. However, brain and liver CSD cDNA sequences differed in the 5' untranslated region. This indicates two forms of CSD mRNA. Analysis of PCR-amplified products of genomic DNA suggests that the brain form results from the use of a 3' alternative internal splicing site within an exon specifically found in liver CSD mRNA. Through selective RT-PCR the brain form was detected in brain only, whereas the liver form was found in liver and kidney. These results indicate a tissue-specific regulation of CSD genomic expression.
Validation of a method for quantitation of the clopidogrel active metabolite, clopidogrel, clopidogrel carboxylic acid, and 2-oxo-clopidogrel in feline plasma.

PubMed

Lyngby, Janne G; Court, Michael H; Lee, Pamela M

2017-08-01

The clopidogrel active metabolite (CAM) is unstable and challenging to quantitate. The objective was to validate a new method for stabilization and quantitation of CAM, clopidogrel, and the inactive metabolites clopidogrel carboxylic acid and 2-oxo-clopiodgrel in feline plasma. Two healthy cats administered clopidogrel to demonstrate assay in vivo utility. Stabilization of CAM was achieved by adding 2-bromo-3'methoxyacetophenone to blood tubes to form a derivatized CAM (CAM-D). Method validation included evaluation of calibration curve linearity, accuracy, and precision; within and between assay precision and accuracy; and compound stability using spiked blank feline plasma. Analytes were measured by high performance liquid chromatography with tandem mass spectrometry. In vivo utility was demonstrated by a pharmacokinetic study of cats given a single oral dose of 18.75mg clopidogrel. The 2-oxo-clopidogrel metabolite was unstable. Clopidogrel, CAM-D, and clopidogrel carboxylic acid appear stable for 1 week at room temperature and 9 months at -80°C. Standard curves showed linearity for CAM-D, clopidogrel, and clopidogrel carboxylic acid (r > 0.99). Between assay accuracy and precision was ≤2.6% and ≤7.1% for CAM-D and ≤17.9% and ≤11.3% for clopidogrel and clopidogrel carboxylic acid. Within assay precision for all three compounds was ≤7%. All three compounds were detected in plasma from healthy cats receiving clopidogrel. This methodology is accurate and precise for simultaneous quantitation of CAM-D, clopidogrel, and clopidogrel carboxylic acid in feline plasma but not 2-oxo-clopidogrel. Validation of this assay is the first step to more fully understanding the use of clopidogrel in cats. Copyright © 2017 Elsevier B.V. All rights reserved.
Generation and dietary modulation of anti-inflammatory electrophilic omega-3 fatty acid derivatives.

PubMed

Cipollina, Chiara; Salvatore, Sonia R; Muldoon, Matthew F; Freeman, Bruce A; Schopfer, Francisco J

2014-01-01

Dietary ω-3 polyunsaturated fatty acids (PUFAs) decrease cardiovascular risk via suppression of inflammation. The generation of electrophilic α,β-unsaturated ketone derivatives of the ω-3 PUFAs docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) in activated human macrophages is catalyzed by cyclooxygenase-2 (Cox-2). These derivatives are potent pleiotropic anti-inflammatory signaling mediators that act via mechanisms including the activation of Nrf2-dependent phase 2 gene expression and suppression of pro-inflammatory NF-κB-driven gene expression. Herein, the endogenous generation of ω-3 PUFAs electrophilic ketone derivatives and their hydroxy precursors was evaluated in human neutrophils. In addition, their dietary modulation was assessed through a randomized clinical trial. Endogenous generation of electrophilic omega-3 PUFAs and their hydroxy precursors was evaluated by mass spectrometry in neutrophils isolated from healthy subjects, both at baseline and upon stimulation with calcium ionophore. For the clinical trial, participants were healthy adults 30-55 years of age with a reported EPA+DHA consumption of ≤300 mg/day randomly assigned to parallel groups receiving daily oil capsule supplements for a period of 4 months containing either 1.4 g of EPA+DHA (active condition, n = 24) or identical appearing soybean oil (control condition, n = 21). Participants and laboratory technicians remained blinded to treatment assignments. 5-lypoxygenase-dependent endogenous generation of 7-oxo-DHA, 7-oxo-DPA and 5-oxo-EPA and their hydroxy precursors is reported in human neutrophils stimulated with calcium ionophore and phorbol 12-myristate 13-acetate (PMA). Dietary EPA+DHA supplementation significantly increased the formation of 7-oxo-DHA and 5-oxo-EPA, with no significant modulation of arachidonic acid (AA) metabolite levels. The endogenous detection of these electrophilic ω-3 fatty acid ketone derivatives supports the precept that the benefit of ω-3 PUFA-rich diets can be attributed to the generation of electrophilic oxygenated metabolites that transduce anti-inflammatory actions rather than the suppression of pro-inflammatory AA metabolites. ClinicalTrials.gov NCT00663871.
Molecular association via halogen bonding and other weak interactions in the crystal structures of 11-bromo-12-oxo-5β-cholan derivatives

NASA Astrophysics Data System (ADS)

Salunke, Deepak B.; Hazra, Braja G.; Gonnade, Rajesh G.; Pore, Vandana S.; Bhadbhade, Mohan M.

2008-12-01

Methyl 3α,7α-diacetoxy-12-oxo-5β-cholan-24-oate 2, methyl 11α-bromo-3α,7α-diacetoxy-12-oxo-5β-cholan-24-oate 3, methyl 11β-bromo-3α,7α-diacetoxy-12-oxo-5β-cholan-24-oate 4 and methyl 11,11-dibromo-3α,7α-diacetoxy-12-oxo-5β-cholan-24-oate 5 were synthesized. The crystal structures of these molecules were resolved to study the effect of bulky bromine atom in the steroid skeleton of cholic acid with different stereo-chemical orientations at C-11 on the two-dimensional arrangement of molecules and solid-state properties. All the molecules associate only via weak intermolecular interactions in their crystal structures, notable one being the Halogen Bonded assembly (C-Br…O) in 5.
40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams

Code of Federal Regulations, 2010 CFR

2010-07-01

... Mercaptan/Ethanol + Hydrogen sulfide Methanol/H.P. Synthesis from natural gas via synthetic gas Oxo Alcohols... + Ammonia n-Propyl alcohol/Hydrogenation of propionaldehyde, Oxo process SAN resin/Suspension polymerization... methanol Acetaldehyde/Oxidation of ethylene with cupric chloride catalyst Acetic acid/Catalytic oxidation...
Molecular cloning and expression of gene encoding aromatic amino acid decarboxylase in 'Vidal blanc' grape berries.

PubMed

Pan, Qiu-Hong; Chen, Fang; Zhu, Bao-Qing; Ma, Li-Yan; Li, Li; Li, Jing-Ming

2012-04-01

The pleasantly fruity and floral 2-phenylethanol are a dominant aroma compound in post-ripening 'Vidal blanc' grapes. However, to date little has been reported about its synthetic pathway in grapevine. In the present study, a full-length cDNA of VvAADC (encoding aromatic amino acid decarboxylase) was firstly cloned from the berries of 'Vidal blanc', an interspecific hybrid variety of Vitis vinifera × Vitis riparia. This sequence encodes a complete open reading frame of 482 amino acids with a calculated molecular mass of 54 kDa and isoelectric point value (pI) of 5.73. The amino acid sequence deduced shared about 79% identity with that of aromatic L: -amino acid decarboxylases (AADCs) from tomato. Real-time PCR analysis indicated that VvAADC transcript abundance presented a small peak at 110 days after full bloom and then a continuous increase at the berry post-ripening stage, which was consistent with the accumulation of 2-phenylethanol, but did not correspond to the trends of two potential intermediates, phenethylamine and 2-phenylacetaldehyde. Furthermore, phenylalanine still exhibited a continuous increase even in post-ripening period. It is thus suggested that 2-phenylethanol biosynthetic pathway mediated by AADC exists in grape berries, but it has possibly little contribution to a considerable accumulation of 2-phenylethanol in post-ripening 'Vidal blanc' grapes.
Effect of starvation and exercise on actual and total activity of the branched-chain 2-oxo acid dehydrogenase complex in rat tissues.

PubMed Central

Wagenmakers, A J; Schepens, J T; Veerkamp, J H

1984-01-01

Starvation does not change the actual activity per g of tissue of the branched-chain 2-oxo acid dehydrogenase in skeletal muscles, but affects the total activity to a different extent, depending on the muscle type. The activity state (proportion of the enzyme present in the active state) does not change in diaphragm and decreases in quadriceps muscle. Liver and kidney show an increase of both activities, without a change of the activity state. In heart and brain no changes were observed. Related to organ wet weights, the actual activity present in the whole-body muscle mass decreases on starvation, whereas the activities present in liver and kidney do not change, or increase slightly. Exercise (treadmill-running) of untrained rats for 15 and 60 min causes a small increase of the actual activity and the activity state of the branched-chain 2-oxo acid dehydrogenase complex in heart and skeletal muscle. Exercise for 1 h, furthermore, increased the actual and the total activity in liver and kidney, without a change of the activity state. In brain no changes were observed. The actual activity per g of tissue in skeletal muscle was less than 2% of that in liver and kidney, both before and after exercise and starvation. Our data indicate that the degradation of branched-chain 2-oxo acids predominantly occurs in liver and to a smaller extent in kidney and skeletal muscle in fed, starved and exercised rats. PMID:6508743
Quantitative high-performance liquid chromatographic determination of retinoids in human serum using on-line solid-phase extraction and column switching. Determination of 9-cis-retinoic acid, 13-cis-retinoic acid, all-trans-retinoic acid, 4-oxo-all-trans-retinoicacid and 4-oxo-13-cis-retinoic acid.

PubMed

Gundersen, T E; Lundanes, E; Blomhoff, R

1997-03-28

A fully automated isocratic high-performance liquid chromatographic method for the determination of 9-cis-retinoic acid, 13-cis-retinoic acid, all-trans-retinoic acid, 4-oxo-13-cis-retinoic acid and 4-oxo-all-trans-retinoic acid, has been developed using on-line solid-phase extraction and a column switching technique allowing clean-up and pre-concentration in a single step. A 500-microliter sample of serum was diluted with 750 microliters of a solution containing 20% acetonitrile and the internal standard 9,10-dimethylanthracene. About 1000 microliters of this mixture was injected on a 20 x 4.6 mm I.D. poly ether ether ketone (PEEK) pre-column with titanium frits packed with Bondapak C18, 37-53 microns, 300 A particles. Proteins and very polar compounds were washed out to waste, from the pre-column, with 0.05% trifluoroacetic acid (TFA)-acetonitrile (8.5:1.5, v/v). More than 200 aliquots of diluted serum could be injected on this pre-column before elevated back-pressure enforces replacement. Components retained on the pre-column were backflushed to the analytical column for separation and detection at 360 nm. Baseline separation was achieved using a single 250 x 4.6 mm I.D. Suplex pKb-100 column and a mobile phase containing 69:10:2:16:3 (v/v) of acetonitrile-methanol-n-butanol-2% ammonium acetate-glacial acetic acid. A total time of analysis of less than 30 min, including sample preparation, was achieved. Recoveries were in the range of 79-86%. The limit of detection was 1-7 ng/ml serum and the precision, in the concentration range 20-1000 ng/ml, was between 1.3 and 4.5% for all five compounds. The method was applied for the analysis of human serum after oral administration of 60 mg Roaccutan. The method is well suited for pharmacological studies, while the endogenous levels of some retinoic acid isomers are below the limit of quantitation.
Arginine-Dependent Acid Resistance in Salmonella enterica Serovar Typhimurium

PubMed Central

Kieboom, Jasper; Abee, Tjakko

2006-01-01

Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid resistance (AR) provided the cells are grown under anoxic conditions and not under the microaerobic conditions used for assessment of AR in E. coli. The role of the arginine decarboxylase pathway in Salmonella AR was shown by the loss of AR in mutants lacking adiA, which encodes arginine decarboxylase; adiC, which encodes the arginine-agmatine antiporter; or adiY, which encodes an AraC-like regulator. Transcription of adiA and adiC was found to be dependent on AdiY, anaerobiosis, and acidic pH. PMID:16855258
Quantitative high-throughput determination of endogenous retinoids in human plasma using triple-stage liquid chromatography/tandem mass spectrometry.

PubMed

Gundersen, Thomas E; Bastani, Nasser E; Blomhoff, Rune

2007-01-01

A high-throughput ultrasensitive analytical method based on liquid chromatography with positive ion atmospheric pressure chemical ionization (APCI) coupled to tandem mass spectrometric detection (LC/MS/MS) was developed for the determination of all-trans-4-oxo-retinoic acid (at4oxoRA), 13-cis-4-oxo-retinoic acid (13c4oxoRA), 13-cis-retinoic acid (13cRA), all-trans-retinoic acid (atRA) and all-trans-retinol (atROH) in human plasma. A stable isotope of atRA was used as internal standard (IS). The analytes and IS were isolated from 100 microL plasma by acetonitrile mono-phase extraction (MPE) performed in black 96-well microtiterplates. A 100 microL injection was focused on-column and chromatographed on an Agilent ZORBAX SB-C18 rapid-resolution high-throughput (RRHT) column with 1.8-microm particles (4.6 mmx50 mm) maintained at 60 degrees C. The initial mobile phase composition was acetonitrile/water/formic acid (10:90:0.1, v/v/v) delivered at 1.8 mL/min. Elution was accomplished by a fast gradient to acetonitrile/methanol/formic acid (90:10:0.1, v/v/v). The method had a chromatographic total run time of 7 min. An Applied Biosystems 4000 Q TRAP linear tandem mass spectrometer equipped with a heated nebulizer (APCI) ionization source was operated in multiple reaction monitoring (MRM) mode with the precursor-to-product ion transitions m/z 315.4-->297 (4-oxo-retinoic acids), 301.2-->205 (retinoic acids), 305.0-->209 (IS) and 269.2-->93 (retinol) used for quantification. The assay was fully validated and found to have acceptable accuracy, precision, linearity, sensitivity and selectivity. The mean extraction recoveries from spiked plasma samples were 80-105% for the various retinoids at three different levels. The intra-day accuracy of the assay was within 8% of nominal and intra-day precision was better than 8% coefficient of variance (CV) for retinoic acids. Inter-day precision results for quality control samples run over a 12-day period alongside clinical samples showed mean precision better than 12.5% CV. The limit of quantification was in the range of 0.1-0.2 ng/mL and the mass limit of detection (mLOD) was in the range 1-4 pg on column for the retinoic acids. The assay has been successfully applied to the analysis of 1700 plasma samples. Copyright (c) 2007 John Wiley & Sons, Ltd.
Enzyme markers of maternal malnutrition in fetal rat brain.

PubMed

Shambaugh, G E; Mankad, B; Derecho, M L; Koehler, R R

1987-01-01

The impact of maternal starvation in late gestation on development of some enzymatic mechanisms concerned with neurotransmission and polyamine synthesis was studied in fetal rat brain. Between 17 and 20 d, acetylcholinesterase and choline acetyltransferase activity increased in fetal brains of fed dams, whereas maternal starvation from day 17 to day 20 resulted in heightened acetylcholinesterase but not choline acetyltransferase activity. Ornithine decarboxylase activity on a per-gram wet-weight basis fell between 17 and 20 d in fetal brain from fed dams. Increasing the duration of maternal starvation resulted in a progressive increase in fetal brain ornithine decarboxylase. Arginine and putrescine levels in the brain were lower in fetuses of starved mothers while spermidine and spermine concentrations were unchanged. Since the Km of ornithine decarboxylase for ornithine was found to vary directly with levels of putrescine in fetal brain, lower concentrations of putrescine and greater ornithine decarboxylase activity in fetal brains from starved mothers suggested that levels of this enzyme may be controlled in part by putrescine. Changes in the maternal nutritional state had no effect on the activity of glutamate decarboxylase in fetal brain, and tissue levels of the product, gamma-aminobutyric acid, were unchanged. Thus changes in ornithine decarboxylase and acetylcholinesterase activity in fetal brain may uniquely reflect biochemical alterations consequent to maternal starvation.
Anti-neuronal anti-bodies in patients with early psychosis.

PubMed

Mantere, O; Saarela, M; Kieseppä, T; Raij, T; Mäntylä, T; Lindgren, M; Rikandi, E; Stoecker, W; Teegen, B; Suvisaari, J

2018-02-01

It may be challenging to distinguish autoimmune encephalitis associated with anti-neuronal autoantibodies from primary psychiatric disorders. Here, serum was drawn from patients with a first-episode psychosis (n=70) or a clinical high-risk for psychosis (n=6) and controls (n=34). We investigated the serum prevalence of 24 anti-neuronal autoantibodies: IgG antibodies for anti-N-methyl-d-aspartate-type glutamate receptor (anti-NMDAR), glutamate and γ-aminobutyric acid alpha and beta receptors (GABA-a, GABA-b), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA), glycine receptor (GlyR), metabotropic glutamate receptor 1 and 5 (mGluR1, mGluR5), anti-Tr/Delta/notch-like epidermal growth factor-related receptor (DNER), contactin-associated protein-like 2 (CASPR2), myelin oligodendrocyte glycoprotein (MOG), glutamic acid decarboxylase-65 (GAD65), collapsin response mediator protein 5/crossveinless-2 (CV2), aquaporin-4 (AQP4), anti-dipeptidyl-peptidase-like protein-6 (DPPX), type 1 anti-neuronal nuclear antibody (ANNA-1, Hu), Ri, Yo, IgLON5, Ma2, zinc finger protein 4 (ZIC4), Rho GTPase-activating protein 26, amphiphysin, and recoverin, as well as IgA and IgM for dopamine-2-receptor (DRD2). Anti-NMDA IgG antibodies were positive with serum titer 1:320 in one patient with a clinical high risk for psychosis. He did not receive a diagnosis of encephalitis after comprehensive neurological evaluation. All other antineuronal autoantibodies were negative and there were no additional findings with immunohistochemistry of brain issues. Copyright © 2017 Elsevier B.V. All rights reserved.
Gum acacia mitigates genetic damage in adenine-induced chronic renal failure in rats.

PubMed

Ali, B H; Al Balushi, K; Al-Husseini, I; Mandel, P; Nemmar, A; Schupp, N; Ribeiro, D A

2015-12-01

Subjects with chronic renal failure (CRF) exhibit oxidative genome damage, which may predispose to carcinogenesis, and Gum acacia (GumA) ameliorates this condition in humans and animals. We evaluated here renal DNA damage and urinary excretion of four nucleic acid oxidation adducts namely 8-oxoguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 8-oxoguanosine (8-oxoGuo) and 8-hydroxy-2-deoxyguanisone (8-OHdg) in rats with adenine (ADE)-induced CRF with and without GumA treatment. Twenty-four rats were divided into four equal groups and treated for 4 weeks. The first group was given normal food and water (control). The second group was given normal food and GumA (15% w/v) in drinking water. The third group was fed powder diet containing adenine (ADE) (0·75% w/w in feed). The fourth group was fed like in the third group, plus GumA in drinking water (15%, w/v). ADE feeding induced CRF (as measured by several physiological, biochemical and histological indices) and also caused a significant genetic damage and significant decreases in urinary 8-oxo Gua and 8-oxoGuo, but not in the other nucleic acids. However, concomitant GumA treatment reduced the level of genetic damage in kidney cells as detected by Comet assay and significantly reversed the effect of adenine on urinary 8-oxoGuo. Treatment with GumA is able to mitigate genetic damage in renal tissues of rats with ADE-induced CRF. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.
N-Acyl-Homoserine Lactone Primes Plants for Cell Wall Reinforcement and Induces Resistance to Bacterial Pathogens via the Salicylic Acid/Oxylipin Pathway[C][W][OPEN

PubMed Central

Schenk, Sebastian T.; Hernández-Reyes, Casandra; Samans, Birgit; Stein, Elke; Neumann, Christina; Schikora, Marek; Reichelt, Michael; Mithöfer, Axel; Becker, Annette; Kogel, Karl-Heinz; Schikora, Adam

2014-01-01

The ability of plants to monitor their surroundings, for instance the perception of bacteria, is of crucial importance. The perception of microorganism-derived molecules and their effector proteins is the best understood of these monitoring processes. In addition, plants perceive bacterial quorum sensing (QS) molecules used for cell-to-cell communication between bacteria. Here, we propose a mechanism for how N-acyl-homoserine lactones (AHLs), a group of QS molecules, influence host defense and fortify resistance in Arabidopsis thaliana against bacterial pathogens. N-3-oxo-tetradecanoyl-l-homoserine lactone (oxo-C14-HSL) primed plants for enhanced callose deposition, accumulation of phenolic compounds, and lignification of cell walls. Moreover, increased levels of oxylipins and salicylic acid favored closure of stomata in response to Pseudomonas syringae infection. The AHL-induced resistance seems to differ from the systemic acquired and the induced systemic resistances, providing new insight into inter-kingdom communication. Consistent with the observation that short-chain AHLs, unlike oxo-C14-HSL, promote plant growth, treatments with C6-HSL, oxo-C10-HSL, or oxo-C14-HSL resulted in different transcriptional profiles in Arabidopsis. Understanding the priming induced by bacterial QS molecules augments our knowledge of plant reactions to bacteria and suggests strategies for using beneficial bacteria in plant protection. PMID:24963057
Multicomponent synthesis of 2-imidazolines.

PubMed

Bon, Robin S; van Vliet, Bart; Sprenkels, Nanda E; Schmitz, Rob F; de Kanter, Frans J J; Stevens, Christian V; Swart, Marcel; Bickelhaupt, F Matthias; Groen, Marinus B; Orru, Romano V A

2005-04-29

[reaction: see text] A multicomponent reaction (MCR) between amines, aldehydes, and isocyanides bearing an acidic alpha-proton gives easy access to a diverse range of highly substituted 2-imidazolines. The limitations of the methodology seem to be determined by the reactivity of the isocyanide and by the steric bulk on the in situ generated imine rather than by the presence of additional functional groups on the imine. Less reactive isocyanides, for example p-nitrobenzyl isocyanide 25a, react successfully with amines and aldehydes, using a catalytic amount of silver(I) acetate. Some of the resulting p-nitrophenyl-substituted 2-imidazolines undergo air oxidation to the corresponding imidazoles. Differences in reactivity of the employed isocyanides are explained with use of DFT calculations. Difficult reactions with ketones instead of aldehydes as the oxo-compound in this MCR are promoted by silver(I) acetate as well.
In vitro toxicological characterization of two arsenosugars and their metabolites.

PubMed

Leffers, Larissa; Ebert, Franziska; Taleshi, Mojtaba S; Francesconi, Kevin A; Schwerdtle, Tanja

2013-07-01

In their recently published Scientific Opinion on Arsenic in Food, the European Food Safety Authority concluded that a risk assessment for arsenosugars is currently not possible, largely because of the lack of relevant toxicological data. To address this issue, we carried out a toxicological in vitro characterization of two arsenosugars and six arsenosugar metabolites. The highly pure synthesized arsenosugars, DMA(V) -sugar-glycerol and DMA(V) -sugar-sulfate, investigated in this study, as well as four metabolites, oxo-dimethylarsenoacetic acid (oxo-DMAA(V) ), oxo-dimethylarsenoethanol (oxo-DMAE(V) ), thio-DMAA(V) and thio-DMAE(V) , exerted neither cytotoxicity nor genotoxicity up to 500 μM exposure in cultured human bladder cells. However, two arsenosugar metabolites, namely dimethyl-arsinic acid (DMA(V) ) and thio-dimethylarsinic acid (thio-DMA(V) ), were toxic to the cells; thio-DMA(V) was even slightly more cytotoxic than arsenite. Additionally, intestinal bioavailability of the arsenosugars was assessed applying the Caco-2 intestinal barrier model. The observed low, but significant transfer rates of the arsenosugars across the barrier model provide further evidence that arsenosugars are intestinally bioavailable. In a cellular system that metabolizes arsenosugars, cellular toxicity likely arises. Thus, in strong contrast to arsenobetaine, arsenosugars cannot be categorized as nontoxic for humans and a risk to human health cannot be excluded. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Association of exposure to benzene and smoking with oxidative damage to nucleic acids by means of biological monitoring of general population volunteers.

PubMed

Tranfo, G; Pigini, D; Paci, E; Marini, F; Bonanni, R C

2017-06-01

In this study, the validation of liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) isotopic dilution method for the determination of benzene and nicotine metabolites in urine was carried out. Limit of detection are 0.026 μg/L for S-phenylmercapturic acid (SPMA), 0.55 μg/L for t,t-muconic acid (t,t-MA), and 12.41 μg/L for the cotinine, and the relative combined uncertainty was also calculated. The study involves 446 healthy volunteer residents since at least 10 years in an area of central Italy. SPMA resulted to be strongly correlated with cotinine (p = 0.75), its concentration in smokers (93) being about ten times than in non/ex-smokers (197/156), while the t,t-MA of smokers is about twice the non/ex-smokers value. A cutoff value for the definition of smoker is set at 100 μg/g creat. Oxidative stress was studied in smokers and non- and ex-smokers by means of the determination of the biomarkers 8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), 8-Oxo-7,8-dihydroguanosine (8-oxoGuo), and 8-Oxo-7,8-dihydroguanine (8-oxoGua): no significant differences were found between smokers and non/ex-smokers, but when subjects are classified according to the cotinine cutoff value, a correlation in smokers' urinary 8-oxodGuo is found with SPMA and cotinine (p = 0.60 and p = 0.57). Results were confirmed by chemometric analysis that also identified the experimental variables most contributing the discrimination as cotinine and t,t-MA.
The gamma-aminobutyric acid shunt contributes to closing the tricarboxylic acid cycle in Synechocystis sp PCC 6803

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, W; Brune, D; Vermaas, WFJ

2014-07-16

A traditional 2-oxoglutarate dehydrogenase complex is missing in the cyanobacterial tricarboxylic acid cycle. To determine pathways that convert 2-oxoglutarate into succinate in the cyanobacterium Synechocystis sp. PCC 6803, a series of mutant strains, Delta sll1981, Delta slr0370, Delta slr1022 and combinations thereof, deficient in 2-oxoglutarate decarboxylase (Sll1981), succinate semialdehyde dehydrogenase (Slr0370), and/or in gamma-aminobutyrate metabolism (Slr1022) were constructed. Like in Pseudomonas aeruginosa, N-acetylornithine aminotransferase, encoded by slr1022, was shown to also function as gamma-aminobutyrate aminotransferase, catalysing gamma-aminobutyrate conversion to succinic semialdehyde. As succinic semialdehyde dehydrogenase converts succinic semialdehyde to succinate, an intact gamma-aminobutyrate shunt is present in Synechocystis. The Deltamore » sll1981 strain, lacking 2-oxoglutarate decarboxylase, exhibited a succinate level that was 60% of that in wild type. However, the succinate level in the Delta slr1022 and Delta slr0370 strains and the Delta sll1981/Delta slr1022 and Delta sll1981/Delta slr0370 double mutants was reduced to 20-40% of that in wild type, suggesting that the gamma-aminobutyrate shunt has a larger impact on metabolite flux to succinate than the pathway via 2-oxoglutarate decarboxylase. C-13-stable isotope analysis indicated that the gamma-aminobutyrate shunt catalysed conversion of glutamate to succinate. Independent of the 2-oxoglutarate decarboxylase bypass, the gamma-aminobutyrate shunt is a major contributor to flux from 2-oxoglutarate and glutamate to succinate in Synechocystis sp. PCC 6803.« less
The Recently Identified Isoleucine Conjugate of cis-12-Oxo-Phytodienoic Acid Is Partially Active in cis-12-Oxo-Phytodienoic Acid-Specific Gene Expression of Arabidopsis thaliana

PubMed Central

Floková, Kristýna; Miersch, Otto; Strnad, Miroslav; Novák, Ondřej; Wasternack, Claus; Hause, Bettina

2016-01-01

Oxylipins of the jasmonate family are active as signals in plant responses to biotic and abiotic stresses as well as in development. Jasmonic acid (JA), its precursor cis-12-oxo-phytodienoic acid (OPDA) and the isoleucine conjugate of JA (JA-Ile) are the most prominent members. OPDA and JA-Ile have individual signalling properties in several processes and differ in their pattern of gene expression. JA-Ile, but not OPDA, is perceived by the SCFCOI1-JAZ co-receptor complex. There are, however, numerous processes and genes specifically induced by OPDA. The recently identified OPDA-Ile suggests that OPDA specific responses might be mediated upon formation of OPDA-Ile. Here, we tested OPDA-Ile-induced gene expression in wild type and JA-deficient, JA-insensitive and JA-Ile-deficient mutant background. Tests on putative conversion of OPDA-Ile during treatments revealed only negligible conversion. Expression of two OPDA-inducible genes, GRX480 and ZAT10, by OPDA-Ile could be detected in a JA-independent manner in Arabidopsis seedlings but less in flowering plants. The data suggest a bioactivity in planta of OPDA-Ile. PMID:27611078
Lipoxygenase6-Dependent Oxylipin Synthesis in Roots Is Required for Abiotic and Biotic Stress Resistance of Arabidopsis1[C][W

PubMed Central

Grebner, Wiebke; Stingl, Nadja E.; Oenel, Ayla; Mueller, Martin J.; Berger, Susanne

2013-01-01

Jasmonates are oxylipin signals that play important roles in the development of fertile flowers and in defense against pathogens and herbivores in leaves. The aim of this work was to understand the synthesis and function of jasmonates in roots. Grafting experiments with a jasmonate-deficient mutant demonstrated that roots produce jasmonates independently of leaves, despite low expression of biosynthetic enzymes. Levels of 12-oxo-phytodienoic acid, jasmonic acid, and its isoleucine derivative increased in roots upon osmotic and drought stress. Wounding resulted in a decrease of preformed 12-oxo-phytodienoic acid concomitant with an increase of jasmonic acid and jasmonoyl-isoleucine. 13-Lipoxygenases catalyze the first step of lipid oxidation leading to jasmonate production. Analysis of 13-lipoxygenase-deficient mutant lines showed that only one of the four 13-lipoxygenases, LOX6, is responsible and essential for stress-induced jasmonate accumulation in roots. In addition, LOX6 was required for production of basal 12-oxo-phytodienoic acid in leaves and roots. Loss-of-function mutants of LOX6 were more attractive to a detritivorous crustacean and more sensitive to drought, indicating that LOX6-derived oxylipins are important for the responses to abiotic and biotic factors. PMID:23444343

Reactivity of molecular dioxygen towards a series of isostructural dichloroiron(III) complexes with tripodal tetraamine ligands: general access to mu-oxodiiron(III) complexes and effect of alpha-fluorination on the reaction kinetics.

PubMed

Thallaj, Nasser K; Rotthaus, Olaf; Benhamou, Leila; Humbert, Nicolas; Elhabiri, Mourad; Lachkar, Mohammed; Welter, Richard; Albrecht-Gary, Anne-Marie; Mandon, Dominique

2008-01-01

We have synthesized the mono, di-, and tri-alpha-fluoro ligands in the tris(2-pyridylmethyl)amine (TPA) series, namely, FTPA, F(2)TPA and F(3)TPA, respectively. Fluorination at the alpha-position of these nitrogen-containing tripods shifts the oxidation potential of the ligand by 45-70 mV per added fluorine atom. The crystal structures of the dichloroiron(II) complexes with FTPA and F(2)TPA reveal that the iron center lies in a distorted octahedral geometry comparable to that already found in TPAFeCl(2). All spectroscopic data indicate that the geometry is retained in solution. These three isostructural complexes all react with molecular dioxygen to yield stable mu-oxodiiron(III) complexes. Crystal structure analyses are reported for each of these three mu-oxo compounds. With TPA, a symmetrical structure is obtained for a dicationic compound with the tripod coordinated in the kappa(4)N coordination mode. With FTPA, the compound is a neutral mu-oxodiiron(III) complex with a kappa(3)N coordination mode of the ligand. Oxygenation of the F(2)TPA complex gave a neutral unsymmetrical compound, the structure of which is reminiscent of that already found with the trifluorinated ligand. On reduction, all mu-oxodiiron(III) complexes revert to the starting iron(II) species. The oxygenation reaction parallels the well-known formation of mu-oxo derivatives from dioxygen in the chemistry of porphyrins reported almost three decades ago. The striking feature of the series of iron(II) precursors is the effect of the ligand on the kinetics of oxygenation of the complexes. Whereas the parent complex undergoes 90 % conversion over 40 h, the monofluorinated ligand provides a complex that has fully reacted after 30 h, whereas the reaction time for the complex with the difluorinated ligand is only 10 h. Analysis of the spectroscopic data reveals that formation of the mu-oxo complexes proceeds in two distinct reversible kinetic steps with k(1) approximately 10 k(2). For TPAFeCl(2) and FTPAFeCl(2) only small variations in the k(1) and k(2) values are observed. By contrast, F(2)TPAFeCl(2) exhibits k(1) and k(2) values that are ten times higher. These differences in kinetics are interpreted in the light of structural and electronic effects, especially the Lewis acidity at the metal center. Our results suggest coordination of dioxygen as an initial step in the process leading to formation of mu-oxodiiron(III) compounds, by contrast with an unlikely outer-sphere reduction of dioxygen, which generally occurs at negative potentials.
Three new compounds from the marine fungus Penicillium sp.

PubMed

Wu, Hong-Hua; Tian, Li; Feng, Bao-Min; Li, Zhi-Feng; Zhang, Qi-Hui; Pei, Yue-Hu

2010-01-01

Continuous research on the ethyl acetate extract of the fermentation broth of the marine fungus Y26-02 (Penicillium sp.) led to the purification of one known and three new compounds. Their structures were elucidated, respectively, as butyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (1), 4-hydroxyphenethyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (2), 3-hydroxybenzyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (3), and desoxypatulinic acid (4) on the basis of their spectroscopic and physico-chemical properties.
Acid Evolution of Escherichia coli K-12 Eliminates Amino Acid Decarboxylases and Reregulates Catabolism.

PubMed

He, Amanda; Penix, Stephanie R; Basting, Preston J; Griffith, Jessie M; Creamer, Kaitlin E; Camperchioli, Dominic; Clark, Michelle W; Gonzales, Alexandra S; Chávez Erazo, Jorge Sebastian; George, Nadja S; Bhagwat, Arvind A; Slonczewski, Joan L

2017-06-15

Acid-adapted strains of Escherichia coli K-12 W3110 were obtained by serial culture in medium buffered at pH 4.6 (M. M. Harden, A. He, K. Creamer, M. W. Clark, I. Hamdallah, K. A. Martinez, R. L. Kresslein, S. P. Bush, and J. L. Slonczewski, Appl Environ Microbiol 81:1932-1941, 2015, https://doi.org/10.1128/AEM.03494-14). Revised genomic analysis of these strains revealed insertion sequence (IS)-driven insertions and deletions that knocked out regulators CadC (acid induction of lysine decarboxylase), GadX (acid induction of glutamate decarboxylase), and FNR (anaerobic regulator). Each acid-evolved strain showed loss of one or more amino acid decarboxylase systems, which normally help neutralize external acid (pH 5 to 6) and increase survival in extreme acid (pH 2). Strains from populations B11, H9, and F11 had an IS 5 insertion or IS-mediated deletion in cadC , while population B11 had a point mutation affecting the arginine activator adiY The cadC and adiY mutants failed to neutralize acid in the presence of exogenous lysine or arginine. In strain B11-1, reversion of an rpoC (RNA polymerase) mutation partly restored arginine-dependent neutralization. All eight strains showed deletion or downregulation of the Gad acid fitness island. Strains with the Gad deletion lost the ability to produce GABA (gamma-aminobutyric acid) and failed to survive extreme acid. Transcriptome sequencing (RNA-seq) of strain B11-1 showed upregulated genes for catabolism of diverse substrates but downregulated acid stress genes (the biofilm regulator ariR , yhiM , and Gad). Other strains showed downregulation of H 2 consumption mediated by hydrogenases ( hya and hyb ) which release acid. Strains F9-2 and F9-3 had a deletion of fnr and showed downregulation of FNR-dependent genes ( dmsABC , frdABCD , hybABO , nikABCDE , and nrfAC ). Overall, strains that had evolved in buffered acid showed loss or downregulation of systems that neutralize unbuffered acid and showed altered regulation of catabolism. IMPORTANCE Experimental evolution of an enteric bacterium under a narrow buffered range of acid pH leads to loss of genes that enhance fitness above or below the buffered pH range, including loss of enzymes that may raise external pH in the absence of buffer. Prominent modes of evolutionary change involve IS-mediated insertions and deletions that knock out key regulators. Over generations of acid stress, catabolism undergoes reregulation in ways that differ for each evolving strain. Copyright © 2017 American Society for Microbiology.
Mitochondrial Impairment May Increase Cellular NAD(P)H: Resazurin Oxidoreductase Activity, Perturbing the NAD(P)H-Based Viability Assays.

PubMed

Aleshin, Vasily A; Artiukhov, Artem V; Oppermann, Henry; Kazantsev, Alexey V; Lukashev, Nikolay V; Bunik, Victoria I

2015-08-21

Cellular NAD(P)H-dependent oxidoreductase activity with artificial dyes (NAD(P)H-OR) is an indicator of viability, as the cellular redox state is important for biosynthesis and antioxidant defense. However, high NAD(P)H due to impaired mitochondrial oxidation, known as reductive stress, should increase NAD(P)H-OR yet perturb viability. To better understand this complex behavior, we assayed NAD(P)H-OR with resazurin (Alamar Blue) in glioblastoma cell lines U87 and T98G, treated with inhibitors of central metabolism, oxythiamin, and phosphonate analogs of 2-oxo acids. Targeting the thiamin diphosphate (ThDP)-dependent enzymes, the inhibitors are known to decrease the NAD(P)H production in the pentose phosphate shuttle and/or upon mitochondrial oxidation of 2-oxo acids. Nevertheless, the inhibitors elevated NAD(P)H-OR with resazurin in a time- and concentration-dependent manner, suggesting impaired NAD(P)H oxidation rather than increased viability. In particular, inhibition of the ThDP-dependent enzymes affects metabolism of malate, which mediates mitochondrial oxidation of cytosolic NAD(P)H. We showed that oxythiamin not only inhibited mitochondrial 2-oxo acid dehydrogenases, but also induced cell-specific changes in glutamate and malate dehydrogenases and/or malic enzyme. As a result, inhibition of the 2-oxo acid dehydrogenases compromises mitochondrial metabolism, with the dysregulated electron fluxes leading to increases in cellular NAD(P)H-OR. Perturbed mitochondrial oxidation of NAD(P)H may thus complicate the NAD(P)H-based viability assay.
Mitochondrial Impairment May Increase Cellular NAD(P)H: Resazurin Oxidoreductase Activity, Perturbing the NAD(P)H-Based Viability Assays

PubMed Central

Aleshin, Vasily A.; Artiukhov, Artem V.; Oppermann, Henry; Kazantsev, Alexey V.; Lukashev, Nikolay V.; Bunik, Victoria I.

2015-01-01

Cellular NAD(P)H-dependent oxidoreductase activity with artificial dyes (NAD(P)H-OR) is an indicator of viability, as the cellular redox state is important for biosynthesis and antioxidant defense. However, high NAD(P)H due to impaired mitochondrial oxidation, known as reductive stress, should increase NAD(P)H-OR yet perturb viability. To better understand this complex behavior, we assayed NAD(P)H-OR with resazurin (Alamar Blue) in glioblastoma cell lines U87 and T98G, treated with inhibitors of central metabolism, oxythiamin, and phosphonate analogs of 2-oxo acids. Targeting the thiamin diphosphate (ThDP)-dependent enzymes, the inhibitors are known to decrease the NAD(P)H production in the pentose phosphate shuttle and/or upon mitochondrial oxidation of 2-oxo acids. Nevertheless, the inhibitors elevated NAD(P)H-OR with resazurin in a time- and concentration-dependent manner, suggesting impaired NAD(P)H oxidation rather than increased viability. In particular, inhibition of the ThDP-dependent enzymes affects metabolism of malate, which mediates mitochondrial oxidation of cytosolic NAD(P)H. We showed that oxythiamin not only inhibited mitochondrial 2-oxo acid dehydrogenases, but also induced cell-specific changes in glutamate and malate dehydrogenases and/or malic enzyme. As a result, inhibition of the 2-oxo acid dehydrogenases compromises mitochondrial metabolism, with the dysregulated electron fluxes leading to increases in cellular NAD(P)H-OR. Perturbed mitochondrial oxidation of NAD(P)H may thus complicate the NAD(P)H-based viability assay. PMID:26308058
Pantothenic acid biosynthesis in zymomonas

DOEpatents

Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

2014-07-01

Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.
Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2}: A new bismuth oxo-selenite bromide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berdonosov, Peter S., E-mail: berdonosov@inorg.chem.msu.ru; Olenev, Andrei V.; Kirsanova, Maria A.

2012-12-15

A new bismuth oxo-selenite bromide Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2} was synthesized and structurally characterized. The crystal structure belongs to the triclinic system (space group P1-bar , Z=2, a=7.1253(7) A, b=10.972(1) A, c=12.117(1) A, {alpha}=67.765(7) Degree-Sign , {beta}=82.188(8) Degree-Sign , {gamma}=78.445(7) Degree-Sign ) and is unrelated to those of other known oxo-selenite halides. It can be considered as an open framework composed of BiO{sub x} or BiO{sub y}Br{sub z} polyhedrons forming channels running along [1 0 0] direction which contain the selenium atoms in pyramidal shape oxygen coordination (SeO{sub 3}E). The spectroscopic properties and thermal stability were studied. Themore » new compound is stable up to 400 Degree-Sign C. - graphical abstract: New bismuth oxo-selenite bromide with new open framework structure. Highlights: Black-Right-Pointing-Pointer New bismuth oxo-selenite bromide was found and structurally characterized. Black-Right-Pointing-Pointer Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2} exhibit a new open framework structure type. Black-Right-Pointing-Pointer BiO{sub x} or BiO{sub y}Br{sub z} polyhedrons form channels in the structure which are decorated by [SeO{sub 3}E] groups.« less
Protonation of a peroxodiiron(III) complex and conversion to a diiron(III/IV) intermediate: implications for proton-assisted O-O bond cleavage in nonheme diiron enzymes.

PubMed

Cranswick, Matthew A; Meier, Katlyn K; Shan, Xiaopeng; Stubna, Audria; Kaizer, Jószef; Mehn, Mark P; Münck, Eckard; Que, Lawrence

2012-10-01

Oxygenation of a diiron(II) complex, [Fe(II)(2)(μ-OH)(2)(BnBQA)(2)(NCMe)(2)](2+) [2, where BnBQA is N-benzyl-N,N-bis(2-quinolinylmethyl)amine], results in the formation of a metastable peroxodiferric intermediate, 3. The treatment of 3 with strong acid affords its conjugate acid, 4, in which the (μ-oxo)(μ-1,2-peroxo)diiron(III) core of 3 is protonated at the oxo bridge. The core structures of 3 and 4 are characterized in detail by UV-vis, Mössbauer, resonance Raman, and X-ray absorption spectroscopies. Complex 4 is shorter-lived than 3 and decays to generate in ~20% yield of a diiron(III/IV) species 5, which can be identified by electron paramagnetic resonance and Mössbauer spectroscopies. This reaction sequence demonstrates for the first time that protonation of the oxo bridge of a (μ-oxo)(μ-1,2-peroxo)diiron(III) complex leads to cleavage of the peroxo O-O bond and formation of a high-valent diiron complex, thereby mimicking the steps involved in the formation of intermediate X in the activation cycle of ribonucleotide reductase.
40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... residues of the herbicide, fluthiacet-methyl, acetic acid [[2-chloro-4-fluoro-5-[(tetrahydro-3-oxo-1H,3H-[1... established for the combined residues of the herbicide fluthiacet-methyland its acid metabolite: acetic acid...
40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... residues of the herbicide, fluthiacet-methyl, acetic acid [[2-chloro-4-fluoro-5-[(tetrahydro-3-oxo-1H,3H-[1... established for the combined residues of the herbicide fluthiacet-methyland its acid metabolite: acetic acid...
40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... residues of the herbicide, fluthiacet-methyl, acetic acid [[2-chloro-4-fluoro-5-[(tetrahydro-3-oxo-1H,3H-[1... established for the combined residues of the herbicide fluthiacet-methyland its acid metabolite: acetic acid...
40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... residues of the herbicide, fluthiacet-methyl, acetic acid [[2-chloro-4-fluoro-5-[(tetrahydro-3-oxo-1H,3H-[1... established for the combined residues of the herbicide fluthiacet-methyland its acid metabolite: acetic acid...
40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... residues of the herbicide, fluthiacet-methyl, acetic acid [[2-chloro-4-fluoro-5-[(tetrahydro-3-oxo-1H,3H-[1... established for the combined residues of the herbicide fluthiacet-methyland its acid metabolite: acetic acid...
5-Oxo-ETE from Nasal Epithelial Cells Upregulates Eosinophil Cation Protein by Eosinophils in Nasal Polyps in vitro.

PubMed

Lin, Lin; Chen, Zheng; Tang, Xinyue; Dai, Fei; Wei, Jinjin; Sun, Guangbin

2018-06-13

5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is a potent eosinophil chemoattractant and activator that is synthesized not only in inflammatory cells but also in bronchial epithelial cells. The purpose of this study is to clarify whether 5-oxo-ETE can promote the production of eosinophil cation protein (ECP) by eosinophils in nasal polyps (NP) in vitro, and whether normal nasal epithelial cells can produce this lipid mediator in response to oxidative stress. Nasal biopsy samples were obtained from normal subjects or subjects with chronic rhinosinusitis with NP. The infiltration of eosinophil in NP was detected and cultured. After that, concentrations of ECP in eosinophil and NP cultures were evaluated after the treatment of 5-oxo-ETE or 5-oxo-ETE + its receptor (OXER) antagonist, pertussis toxin (PT). Then we studied the synthesis of 5-oxo-ETE after H2O2 stimulation by normal nasal epithelial cells and by epithelial cells of NP alone in the cultures, and also determined the OXER expression in NP. The number of infiltrative eosinophils in NP was increased. The ECP levels in eosinophil and NP cultures were enhanced after the administration of 5-oxo-ETE, and decreased by the PT treatment. 5-Oxo-ETE was upregulated in the cultures of nasal epithelial cells in the presence of H2O2 and of NP epithelial cells alone. The OXER was expressed in inflammatory cells, and not in epithelial cells. 5-Oxo-ETE produced by nasal epithelial cells may play a role in the formation and development of NP. © 2018 S. Karger AG, Basel.
Acid-adapted strains of Escherichia coli K-12 obtained by experimental evolution.

PubMed

Harden, Mark M; He, Amanda; Creamer, Kaitlin; Clark, Michelle W; Hamdallah, Issam; Martinez, Keith A; Kresslein, Robert L; Bush, Sean P; Slonczewski, Joan L

2015-03-01

Enteric bacteria encounter a wide range of pHs throughout the human intestinal tract. We conducted experimental evolution of Escherichia coli K-12 to isolate clones with increased fitness during growth under acidic conditions (pH 4.5 to 4.8). Twenty-four independent populations of E. coli K-12 W3110 were evolved in LBK medium (10 g/liter tryptone, 5 g/liter yeast extract, 7.45 g/liter KCl) buffered with homopiperazine-N,N'-bis-2-(ethanosulfonic acid) and malate at pH 4.8. At generation 730, the pH was decreased to 4.6 with HCl. By 2,000 generations, all populations had achieved higher endpoint growth than the ancestor at pH 4.6 but not at pH 7.0. All evolving populations showed a progressive loss of activity of lysine decarboxylase (CadA), a major acid stress enzyme. This finding suggests a surprising association between acid adaptation and moderation of an acid stress response. At generation 2,000, eight clones were isolated from four populations, and their genomes were sequenced. Each clone showed between three and eight missense mutations, including one in a subunit of the RNA polymerase holoenzyme (rpoB, rpoC, or rpoD). Missense mutations were found in adiY, the activator of the acid-inducible arginine decarboxylase (adiA), and in gcvP (glycine decarboxylase), a possible acid stress component. For tests of fitness relative to that of the ancestor, lacZ::kan was transduced into each strain. All acid-evolved clones showed a high fitness advantage at pH 4.6. With the cytoplasmic pH depressed by benzoate (at external pH 6.5), acid-evolved clones showed decreased fitness; thus, there was no adaptation to cytoplasmic pH depression. At pH 9.0, acid-evolved clones showed no fitness advantage. Thus, our acid-evolved clones showed a fitness increase specific to low external pH. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Acid-Adapted Strains of Escherichia coli K-12 Obtained by Experimental Evolution

PubMed Central

Harden, Mark M.; He, Amanda; Creamer, Kaitlin; Clark, Michelle W.; Hamdallah, Issam; Martinez, Keith A.; Kresslein, Robert L.; Bush, Sean P.

2015-01-01

Enteric bacteria encounter a wide range of pHs throughout the human intestinal tract. We conducted experimental evolution of Escherichia coli K-12 to isolate clones with increased fitness during growth under acidic conditions (pH 4.5 to 4.8). Twenty-four independent populations of E. coli K-12 W3110 were evolved in LBK medium (10 g/liter tryptone, 5 g/liter yeast extract, 7.45 g/liter KCl) buffered with homopiperazine-N,N′-bis-2-(ethanosulfonic acid) and malate at pH 4.8. At generation 730, the pH was decreased to 4.6 with HCl. By 2,000 generations, all populations had achieved higher endpoint growth than the ancestor at pH 4.6 but not at pH 7.0. All evolving populations showed a progressive loss of activity of lysine decarboxylase (CadA), a major acid stress enzyme. This finding suggests a surprising association between acid adaptation and moderation of an acid stress response. At generation 2,000, eight clones were isolated from four populations, and their genomes were sequenced. Each clone showed between three and eight missense mutations, including one in a subunit of the RNA polymerase holoenzyme (rpoB, rpoC, or rpoD). Missense mutations were found in adiY, the activator of the acid-inducible arginine decarboxylase (adiA), and in gcvP (glycine decarboxylase), a possible acid stress component. For tests of fitness relative to that of the ancestor, lacZ::kan was transduced into each strain. All acid-evolved clones showed a high fitness advantage at pH 4.6. With the cytoplasmic pH depressed by benzoate (at external pH 6.5), acid-evolved clones showed decreased fitness; thus, there was no adaptation to cytoplasmic pH depression. At pH 9.0, acid-evolved clones showed no fitness advantage. Thus, our acid-evolved clones showed a fitness increase specific to low external pH. PMID:25556191
Teratogenicity and transplacental pharmacokinetics of 13-cis-retinoic acid in rabbits.

PubMed

Eckhoff, C; Chari, S; Kromka, M; Staudner, H; Juhasz, L; Rudiger, H; Agnish, N

1994-03-01

No embryotoxic or teratogenic effects, considered to be treatment related, were observed in rabbits after daily oral doses of 3 mg/kg of 13-cis-retinoic acid (13-cis-RA) from Day 8 to Day 11 of gestation. In contrast, treatment with 15 mg/kg/day significantly increased the rate of fetal resorptions (22%) and 13 out of 68 surviving fetuses (16%) were malformed. Pharmacokinetic studies with both dosing regimens of 13-cis-RA in pregnant rabbits showed that on Day 11 of gestation, high concentrations of parent compound, 13-cis-RA, and its major metabolite, 13-cis-4-oxoRA, existed in maternal plasma. Much lower concentrations were found for all-trans-4-oxoRA and all-trans-RA. The area under the concentration-time curve (AUC) of all-trans-RA following the 15 mg/kg/day dosing regimen of 13-cis-RA was only 1.2% that of parent compound 13-cis-RA. At this dose, embryo levels of 13-cis-RA, 13-cis-4-oxoRA, and all-trans-4-oxoRA were 2.5-, 4.7-, and 3.6-fold higher by AUC comparison (24-hr period of Day 11) compared with the dose of 3 mg/kg. However, embryo levels of all-trans-RA were virtually identical at both doses and were, in fact, somewhat lower than endogenous concentrations measured in untreated rabbit embryos. In contrast to mice, where isomerization from 13-cis- to all-trans-RA was suggested to be crucial for the teratogenic action of 13-cis-RA, we found that the teratogenic action of 13-cis-RA (15 mg/kg/day) in rabbits is characterized by increased whole embryo concentrations of 13-cis-RA, 13-cis-4-oxoRA, and all-trans-4-oxoRA, but not of all-trans-RA.
GLUTAMIC DECARBOXYLASE OF ERGOT, CLAVICEPS PURPUREA

PubMed Central

Anderson, John A.; Cheldelin, Vernon H.; King, Tsoo E.

1961-01-01

Anderson, John A. (Oregon State University, Corvallis), Vernon H. Cheldelin, and Tsoo E. King. Glutamic decarboxylase of ergot, Claviceps purpurea. J. Bacteriol. 82:354–358. 1961.—l-Glutamic acid is the only naturally occurring amino acid which can be decarboxylated by cell-free extracts of Claviceps purpurea. This decarboxylase was partially purified and the properties of the enzyme studied. The specific activity of the purified preparation was 111 μliters per 10 min per mg of protein. The products formed, stability, inhibition, stimulation of activity with pyridoxal phosphate, and pH activity curve were typical of l-glutamic decarboxylase in Escherichia coli and other microorganisms. The substrate constants at pH 4.6, 5.25, and 5.65 were 0.0169 m, 0.0174 m, and 0.0139 m, respectively. The respective maximal velocities at these pH values were 104, 104, and 90 μliters per 10 min. The pH optimum was 4.8 to 5.2. The enzyme was unstable below pH 4.5 and it was suggested that the fall in activity at the lower end of the pH curve was due to inactivation of the enzyme. The decrease in activity above pH 5.2 did not appear to be due to a change in affinity of enzyme for substrate but to a change of the enzyme-substrate complex into an inactive form. PMID:13683214
Induction of an oxalate decarboxylase in the filamentous fungus Trametes versicolor by addition of inorganic acids.

PubMed

Zhu, Cui Xia; Hong, Feng

2010-01-01

In order to improve yields and to reduce the cost of oxalate decarboxylase (OxDC, EC 4.1.1.2), the induction of OxDC in the white-rot fungus Trametes versicolor was studied in this work. OxDC was induced by addition of inorganic acids including hydrochloric acid, sulfuric acid, and phosphoric acid to culture media. The results showed that all the acids could enhance OxDC expression. The activity of the acid-induced OxDC rose continuously. All of the OxDC volumetric activities induced by the inorganic acids were higher than 20.0 U/L and were two times higher than that obtained with oxalic acid. OxDC productivity was around 4.0 U*L(-1)*day(-1). The highest specific activity against total protein was 3.2 U/mg protein at day 8 after induction of sulfuric acid, and the specific activity against mycelial dry weight was 10.6 U/g at day 9 after induction of hydrochloric acid. The growth of mycelia was inhibited slightly when the pH values in culture media was around 2.5-3.0, while the growth was inhibited heavily when the pH was lower than 2.5.
[Characteristics of the glutamate decarboxylase reaction in homogenates of various regions of the rat brain].

PubMed

Rozanov, V A

1987-01-01

The glutamate decarboxylase activity in rough homogenates of cerebellum, cortex and truncal part of the rat brain was studied under different conditions of incubation: in the presence of 25 mM glutamate sodium, 0.4 mM pyridoxal-5'-phosphate and both these components. It is found that the initial glutamate decarboxylase activity in cerebellum homogenates is approximately twice as high as in the cortex and trunk homogenates. Addition of the substrate and cofactor, especially in the combination, stimulates considerably the yield of gamma-aminobutyric acid (GABA) in the glutamate decarboxylase reaction, the most pronounced activation being observed in the truncal homogenates. The glutamate/GABA relation both initial and after the completion of the reaction is the maximal in the cortex and minimal in the truncal part of the brain. The data obtained evidence for the differences in the content of the GABA-producing enzyme rather than for the presence of the specific mechanisms of the enzyme regulation in different brain areas.

Characterization of a carbon-carbon hydrolase from Mycobacterium tuberculosis involved in cholesterol metabolism.

PubMed

Lack, Nathan A; Yam, Katherine C; Lowe, Edward D; Horsman, Geoff P; Owen, Robin L; Sim, Edith; Eltis, Lindsay D

2010-01-01

In the recently identified cholesterol catabolic pathway of Mycobacterium tuberculosis, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (HsaD) is proposed to catalyze the hydrolysis of a carbon-carbon bond in 4,5-9,10-diseco-3-hydroxy-5,9,17-tri-oxoandrosta-1(10),2-diene-4-oic acid (DSHA), the cholesterol meta-cleavage product (MCP) and has been implicated in the intracellular survival of the pathogen. Herein, purified HsaD demonstrated 4-33 times higher specificity for DSHA (k(cat)/K(m) = 3.3 +/- 0.3 x 10(4) m(-1) s(-1)) than for the biphenyl MCP 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) and the synthetic analogue 8-(2-chlorophenyl)-2-hydroxy-5-methyl-6-oxoocta-2,4-dienoic acid (HOPODA), respectively. The S114A variant of HsaD, in which the active site serine was substituted with alanine, was catalytically impaired and bound DSHA with a K(d) of 51 +/- 2 mum. The S114A.DSHA species absorbed maximally at 456 nm, 60 nm red-shifted versus the DSHA enolate. Crystal structures of the variant in complex with HOPDA, HOPODA, or DSHA to 1.8-1.9 Aindicate that this shift is due to the enzyme-induced strain of the enolate. These data indicate that the catalytic serine catalyzes tautomerization. A second role for this residue is suggested by a solvent molecule whose position in all structures is consistent with its activation by the serine for the nucleophilic attack of the substrate. Finally, the alpha-helical lid covering the active site displayed a ligand-dependent conformational change involving differences in side chain carbon positions of up to 6.7 A, supporting a two-conformation enzymatic mechanism. Overall, these results provide novel insights into the determinants of specificity in a mycobacterial cholesterol-degrading enzyme as well as into the mechanism of MCP hydrolases.
40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...
40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...
40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...
40 CFR 414.70 - Applicability; description of the bulk organic chemicals subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., Calcium Salt Maleic Anhydride Methacrylic Acid *Methacrylic Acid Esters Methane Methyl Ethyl Ketone Methyl Methacrylate Methyl Tert-Butyl Ether Methylisobutyl Ketone *n-Alkanes n-Butyl Alcohol n-Butylacetate n... Acid Nylon Salt Oxalic Acid *Oxo Aldehydes—Alcohols Pentaerythritol Pentane *Pentenes *Petroleum...
Differential metabolism of diastereoisomeric diterpenes by Preussia minima, found as endophytic fungus in Cupressus lusitanica.

PubMed

Ud Din, Zia; de Medeiros, L S; Abreu, L M; Pfenning, Ludwig H; Lopes Jymeni, D B; Rodrigues-Filho, E

2018-08-01

The plant diastereoisomeric diterpenes ent-pimara-8(14)-15-dien-19-oic acid, obtained from Viguiera arenaria, and isopimara-8(14)-15-dien-18-oic acid, isolated from Cupressus lusitanica, were distinctly functionalized by the enzymes produced in whole cell cultures of the fungus Preussia minima, isolated from surface sterilized stems of C. lusitanica. The ent-pimaradienoic acid was transformed into the known 7β-hydroxy-ent-pimara-8(14)-15-dien-19-oic acid, and into the novel diterpenes 7-oxo-8 β-hydroxy-ent-pimara-8(14)-15-dien-19-oic and 7-oxo-9β-hydroxy-ent-pimara-8(14)-15-dien-19-oic acids. Isopimara-8(14)-15-dien-18-oic acid was converted into novel diterpenes 11α-hydroxyisopimara-8(14)-15-dien-18-oic acid, 7β,11α-dihydroxyisopimara-8(14)-15-dien-18-oic acid, and 1β,11α-dihydroxyisopimara-8(14)-15-dien-18-oic acid, along with the known 7β-hydroxyisopimara-8(14)-15-dien-18-oic acid. All compounds were isolated and fully characterized by 1D and 2D NMR, especially 13 C NMR. The diterpene bioproduct 7-oxo-9β-hydroxy-ent-pimara-8(14)-15-dien-19-oic acid is an isomer of sphaeropsidin C, a phytotoxin that affects cypress trees produced by Shaeropsis sapinea, one of the main phytopathogen of Cupressus. The differential metabolism of the diterpene isomers used as substrates for biotransformation was interpreted with the help of computational molecular docking calculations, considering as target enzymes those of cytochrome P450 group. Copyright © 2018 Elsevier Inc. All rights reserved.
An adaptation to life in acid through a novel mevalonate pathway

DOE PAGES

Vinokur, Jeffrey M.; Cummins, Matthew C.; Korman, Tyler P.; ...

2016-12-22

Here, extreme acidophiles are capable of growth at pH values near zero. Sustaining life in acidic environments requires extensive adaptations of membranes, proton pumps, and DNA repair mechanisms. Here we describe an adaptation of a core biochemical pathway, the mevalonate pathway, in extreme acidophiles. Two previously known mevalonate pathways involve ATP dependent decarboxylation of either mevalonate 5-phosphate or mevalonate 5-pyrophosphate, in which a single enzyme carries out two essential steps: (1) phosphorylation of the mevalonate moiety at the 3-OH position and (2) subsequent decarboxylation. We now demonstrate that in extreme acidophiles, decarboxylation is carried out by two separate steps: previouslymore » identified enzymes generate mevalonate 3,5-bisphosphate and a new decarboxylase we describe here, mevalonate 3,5-bisphosphate decarboxylase, produces isopentenyl phosphate. Why use two enzymes in acidophiles when one enzyme provides both functionalities in all other organisms examined to date? We find that at low pH, the dual function enzyme, mevalonate 5-phosphate decarboxylase is unable to carry out the first phosphorylation step, yet retains its ability to perform decarboxylation. We therefore propose that extreme acidophiles had to replace the dual-purpose enzyme with two specialized enzymes to efficiently produce isoprenoids in extremely acidic environments.« less
An adaptation to life in acid through a novel mevalonate pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vinokur, Jeffrey M.; Cummins, Matthew C.; Korman, Tyler P.

Here, extreme acidophiles are capable of growth at pH values near zero. Sustaining life in acidic environments requires extensive adaptations of membranes, proton pumps, and DNA repair mechanisms. Here we describe an adaptation of a core biochemical pathway, the mevalonate pathway, in extreme acidophiles. Two previously known mevalonate pathways involve ATP dependent decarboxylation of either mevalonate 5-phosphate or mevalonate 5-pyrophosphate, in which a single enzyme carries out two essential steps: (1) phosphorylation of the mevalonate moiety at the 3-OH position and (2) subsequent decarboxylation. We now demonstrate that in extreme acidophiles, decarboxylation is carried out by two separate steps: previouslymore » identified enzymes generate mevalonate 3,5-bisphosphate and a new decarboxylase we describe here, mevalonate 3,5-bisphosphate decarboxylase, produces isopentenyl phosphate. Why use two enzymes in acidophiles when one enzyme provides both functionalities in all other organisms examined to date? We find that at low pH, the dual function enzyme, mevalonate 5-phosphate decarboxylase is unable to carry out the first phosphorylation step, yet retains its ability to perform decarboxylation. We therefore propose that extreme acidophiles had to replace the dual-purpose enzyme with two specialized enzymes to efficiently produce isoprenoids in extremely acidic environments.« less
Enchancement of Gamma-Aminobutyric Acid Production by Co-Localization of Neurospora crassa OR74A Glutamate Decarboxylase with Escherichia coli GABA Transporter Via Synthetic Scaffold Complex.

PubMed

Somasundaram, Sivachandiran; Maruthamuthu, Murali Kannan; Ganesh, Irisappan; Eom, Gyeong Tae; Hong, Soon Ho

2017-09-28

Gamma-aminobutyric acid is a precursor of nylon-4, which is a promising heat-resistant biopolymer. GABA can be produced from the decarboxylation of glutamate by glutamate decarboxylase. In this study, a synthetic scaffold complex strategy was employed involving the Neurospora crassa glutamate decarboxylase (GadB) and Escherichia coli GABA antiporter (GadC) to improve GABA production. To construct the complex, the SH3 domain was attached to the N. crassa GadB, and the SH3 ligand was attached to the N-terminus, middle, and C-terminus of E. coli GadC. In the C-terminus model, 5.8 g/l of GABA concentration was obtained from 10 g/l glutamate. When a competing pathway engineered strain was used, the final GABA concentration was further increased to 5.94 g/l, which corresponds to 97.5% of GABA yield. With the introduction of the scaffold complex, the GABA productivity increased by 2.9 folds during the initial culture period.
Diagnostic accuracy of the anti-glutamic acid decarboxylase antibody in type 1 diabetes mellitus: Comparison between radioimmunoassay and enzyme-linked immunosorbent assay.

PubMed

Murata, Takashi; Tsuzaki, Kokoro; Nirengi, Shinsuke; Watanabe, Tomokazu; Mizutani, Yukako; Okada, Hayami; Tsukamoto, Masami; Odori, Shinji; Nakagawachi, Reiko; Kawaguchi, Yaeko; Yoshioka, Fumi; Yamada, Kazunori; Shimatsu, Akira; Kotani, Kazuhiko; Satoh-Asahara, Noriko; Sakane, Naoki

2017-07-01

The distributer of the anti-glutamic acid decarboxylase antibody assay kit using radioimmunoassay (RIA) recently announced its discontinuation, and proposed an alternative kit using enzyme-linked immunosorbent assay (ELISA). The aim of the present study was to investigate the diagnostic values of the anti-glutamic acid decarboxylase antibody by RIA and ELISA among type 1 diabetes mellitus patients and control participants. A total of 79 type 1 diabetes mellitus patients and 79 age-matched controls were enrolled and assessed using RIA and ELISA. Sensitivity, specificity, positive predictive values and negative predictive values were calculated for cut-off values (RIA = 1.5 U/mL and ELISA = 5.0 U/mL, respectively). Kappa coefficients were used to test for agreements between the RIA and ELISA methods regarding the diagnosis of type 1 diabetes mellitus. The sensitivity, specificity, positive predictive values, and negative predictive values for diagnosing type 1 diabetes mellitus were 57.0, 97.5, 95.7, and 69.4% by RIA, and 60.8, 100.0, 100.0 and 71.8% by ELISA, respectively. The diagnosis of type 1 diabetes mellitus using the RIA and ELISA methods showed substantial agreement with the kappa values of 0.74 for all participants, and of 0.64 for the acute type; however, there was moderate agreement with the kappa value of 0.56 for the slowly progressive type. The present study suggests that both anti-glutamic acid decarboxylase antibody by RIA and ELISA was useful for diagnosing type 1 diabetes mellitus. However, in the slowly progressive type, the degree of agreement of these two kits was poorer compared with those in all participants or in the acute type. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.
Differential Gene Expression by Lactobacillus plantarum WCFS1 in Response to Phenolic Compounds Reveals New Genes Involved in Tannin Degradation.

PubMed

Reverón, Inés; Jiménez, Natalia; Curiel, José Antonio; Peñas, Elena; López de Felipe, Félix; de Las Rivas, Blanca; Muñoz, Rosario

2017-04-01

Lactobacillus plantarum is a lactic acid bacterium that can degrade food tannins by the successive action of tannase and gallate decarboxylase enzymes. In the L. plantarum genome, the gene encoding the catalytic subunit of gallate decarboxylase ( lpdC , or lp_2945 ) is only 6.5 kb distant from the gene encoding inducible tannase ( L. plantarum tanB [ tanB Lp ], or lp_2956 ). This genomic context suggests concomitant activity and regulation of both enzymatic activities. Reverse transcription analysis revealed that subunits B ( lpdB , or lp_0271 ) and D ( lpdD , or lp_0272 ) of the gallate decarboxylase are cotranscribed, whereas subunit C ( lpdC , or lp_2945 ) is cotranscribed with a gene encoding a transport protein ( gacP , or lp_2943 ). In contrast, the tannase gene is transcribed as a monocistronic mRNA. Investigation of knockout mutations of genes located in this chromosomal region indicated that only mutants of the gallate decarboxylase (subunits B and C), tannase, GacP transport protein, and TanR transcriptional regulator ( lp_2942 ) genes exhibited altered tannin metabolism. The expression profile of genes involved in tannin metabolism was also analyzed in these mutants in the presence of methyl gallate and gallic acid. It is noteworthy that inactivation of tanR suppresses the induction of all genes overexpressed in the presence of methyl gallate and gallic acid. This transcriptional regulator was also induced in the presence of other phenolic compounds, such as kaempferol and myricetin. This study complements the catalog of L. plantarum expression profiles responsive to phenolic compounds, which enable this bacterium to adapt to a plant food environment. IMPORTANCE Lactobacillus plantarum is a bacterial species frequently found in the fermentation of vegetables when tannins are present. L. plantarum strains degrade tannins to the less-toxic pyrogallol by the successive action of tannase and gallate decarboxylase enzymes. The genes encoding these enzymes are located close to each other in the chromosome, suggesting concomitant regulation. Proteins involved in tannin metabolism and regulation, such GacP (gallic acid permease) and TanR (tannin transcriptional regulator), were identified by differential gene expression in knockout mutants with mutations in genes from this region. This study provides insights into the highly coordinated mechanisms that enable L. plantarum to adapt to plant food fermentations. Copyright © 2017 American Society for Microbiology.
Differential Gene Expression by Lactobacillus plantarum WCFS1 in Response to Phenolic Compounds Reveals New Genes Involved in Tannin Degradation

PubMed Central

Reverón, Inés; Jiménez, Natalia; Curiel, José Antonio; Peñas, Elena; López de Felipe, Félix; de las Rivas, Blanca

2017-01-01

ABSTRACT Lactobacillus plantarum is a lactic acid bacterium that can degrade food tannins by the successive action of tannase and gallate decarboxylase enzymes. In the L. plantarum genome, the gene encoding the catalytic subunit of gallate decarboxylase (lpdC, or lp_2945) is only 6.5 kb distant from the gene encoding inducible tannase (L. plantarum tanB [tanBLp], or lp_2956). This genomic context suggests concomitant activity and regulation of both enzymatic activities. Reverse transcription analysis revealed that subunits B (lpdB, or lp_0271) and D (lpdD, or lp_0272) of the gallate decarboxylase are cotranscribed, whereas subunit C (lpdC, or lp_2945) is cotranscribed with a gene encoding a transport protein (gacP, or lp_2943). In contrast, the tannase gene is transcribed as a monocistronic mRNA. Investigation of knockout mutations of genes located in this chromosomal region indicated that only mutants of the gallate decarboxylase (subunits B and C), tannase, GacP transport protein, and TanR transcriptional regulator (lp_2942) genes exhibited altered tannin metabolism. The expression profile of genes involved in tannin metabolism was also analyzed in these mutants in the presence of methyl gallate and gallic acid. It is noteworthy that inactivation of tanR suppresses the induction of all genes overexpressed in the presence of methyl gallate and gallic acid. This transcriptional regulator was also induced in the presence of other phenolic compounds, such as kaempferol and myricetin. This study complements the catalog of L. plantarum expression profiles responsive to phenolic compounds, which enable this bacterium to adapt to a plant food environment. IMPORTANCE Lactobacillus plantarum is a bacterial species frequently found in the fermentation of vegetables when tannins are present. L. plantarum strains degrade tannins to the less-toxic pyrogallol by the successive action of tannase and gallate decarboxylase enzymes. The genes encoding these enzymes are located close to each other in the chromosome, suggesting concomitant regulation. Proteins involved in tannin metabolism and regulation, such GacP (gallic acid permease) and TanR (tannin transcriptional regulator), were identified by differential gene expression in knockout mutants with mutations in genes from this region. This study provides insights into the highly coordinated mechanisms that enable L. plantarum to adapt to plant food fermentations. PMID:28115379
Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae).

PubMed

Zheoat, Ahmed M; Gray, Alexander I; Igoli, John O; Kennedy, Alan R; Ferro, Valerie A

2017-09-01

The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2 S ,3 R )-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carb-oxy-lic acid dimethyl sulfoxide monosolvate], C 6 H 6 O 7 ·C 2 H 6 OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2 S ,3 R )-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carboxyl-ate], C 8 H 10 O 7 , (II). Compound (I) forms a layered structure with alternating layers of lactone and solvent mol-ecules, that include a two-dimensional hydrogen-bonding construct. Compound (II) has two crystallographically independent and conformationally similar mol-ecules per asymmetric unit and forms a one-dimensional hydrogen-bonding construct. The known absolute configuration for both compounds has been confirmed.
Development of perampanel in epilepsy.

PubMed

Satlin, A; Kramer, L D; Laurenza, A

2013-01-01

Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors play a key role in mediating glutamatergic transmission in the cortex. Perampanel (2-[2-oxo-1-phenyl-5-pyridin-2-yl-1,2-dihydropyridin-3-yl] benzonitrile) is a potent, orally active, highly selective, non-competitive AMPA-type glutamate receptor antagonist, identified via a focused discovery program at Eisai Research Laboratories. Development of perampanel as adjunctive therapy for the treatment of partial-onset seizures was planned in keeping with regulatory guidance and guidelines on antiepileptic drug (AED) development. This is the first AED with a specific action on glutamate-mediated excitatory neurotransmission to show evidence of efficacy and tolerability in reducing treatment-refractory partial-onset seizures in Phase III clinical trials. Perampanel (Fycompa(®)) has been approved in the EU and the United States for adjunctive treatment of partial-onset seizures. © 2013 John Wiley & Sons A/S.
ENGINEERING THE BIOSYNTHESIS OF STYRENE IN YEAST

EPA Science Inventory

The strategy pursued was to insert genes for phenylalanine ammonia lysase (pal) and phenolic acid decarboxylase (pad) into the yeast that would convert phenylalanine to styrene through a cinnamic acid intermediate.

Erythrocyte membrane docosapentaenoic acid levels are associated with islet autoimmunity: The Diabetes Autoimmunity Study in the Young

PubMed Central

Norris, Jill M.; Kroehl, Miranda; Fingerlin, Tasha E.; Frederiksen, Brittni N.; Seifert, Jennifer; Wong, Randall; Clare-Salzler, Michael; Rewers, Marian

2013-01-01

Aims/hypotheses We previously reported that lower n-3 fatty acid intake and levels in erythrocyte membranes were associated with increased risk of islet autoimmunity (IA) but not progression to type 1 diabetes in children at increased risk for diabetes. We hypothesise that specific n-3 fatty acids and genetic markers contribute synergistically to this increased risk of IA in the Diabetes Autoimmunity Study in the Young (DAISY). Methods DAISY is following 2547 children at increased risk for type 1 diabetes for the development of IA, defined as being positive for glutamic acid decarboxylase (GAD)65, IA-2 or insulin autoantibodies on two consecutive visits. Using a case-cohort design, erythrocyte membrane fatty acids and dietary intake were measured prospectively in 58 IA-positive children and 299 IA-negative children. Results Lower membrane levels of the n-3 fatty acid, docosapentaenoic acid (DPA), were predictive of IA (HR 0.23; 95% CI 0.09,0.55), while alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were not, adjusting for HLA and diabetes family history. We examined whether the effect of dietary intake of the n-3 fatty acid ALA on IA risk was modified by fatty acid elongation and desaturation genes. Adjusting for HLA, diabetes family history, ethnicity, energy intake and questionnaire type, ALA intake was significantly more protective for IA in the presence of an increasing number of minor alleles at FADS1 rs174556 (pinteraction=0.017), at FADS2 rs174570 (pinteraction=0.016) and at FADS2 rs174583 (pinteraction=0.045). Conclusions/interpretation The putative protective effect of n-3 fatty acids on IA may result from a complex interaction between intake and genetically-controlled fatty acid desaturation. PMID:24240437
Probing hydrogen and halogen-oxo interactions in uranyl coordination polymers: a combined crystallographic and computational study

DOE PAGES

Carter, Korey P.; Kalaj, Mark; Kerridge, Andrew; ...

2018-01-01

Four uranyl compounds containing either benzoic acid ( 1 ), m -chlorobenzoic acid ( 2 ), m -bromobenzoic acid ( 3 ), or m -iodobenzoic acid ( 4 ) are described, and the latter two compounds are used to probe non-covalent interaction strengths via structural, vibrational, and computational means.
Structure and function of PA4872 from Pseudomonas aeruginosa, a novel class of oxaloacetate decarboxylase from the PEP mutase/isocitrate lyase superfamily.

PubMed

Narayanan, Buvaneswari C; Niu, Weiling; Han, Ying; Zou, Jiwen; Mariano, Patrick S; Dunaway-Mariano, Debra; Herzberg, Osnat

2008-01-08

Pseudomonas aeruginosa PA4872 was identified by sequence analysis as a structurally and functionally novel member of the PEP mutase/isocitrate lyase superfamily and therefore targeted for investigation. Substrate screens ruled out overlap with known catalytic functions of superfamily members. The crystal structure of PA4872 in complex with oxalate (a stable analogue of the shared family alpha-oxyanion carboxylate intermediate/transition state) and Mg2+ was determined at 1.9 A resolution. As with other PEP mutase/isocitrate lyase superfamily members, the protein assembles into a dimer of dimers with each subunit adopting an alpha/beta barrel fold and two subunits swapping their barrel's C-terminal alpha-helices. Mg2+ and oxalate bind in the same manner as observed with other superfamily members. The active site gating loop, known to play a catalytic role in the PEP mutase and lyase branches of the superfamily, adopts an open conformation. The Nepsilon of His235, an invariant residue in the PA4872 sequence family, is oriented toward a C(2) oxygen of oxalate analogous to the C(3) of a pyruvyl moiety. Deuterium exchange into alpha-oxocarboxylate-containing compounds was confirmed by 1H NMR spectroscopy. Having ruled out known activities, the involvement of a pyruvate enolate intermediate suggested a decarboxylase activity of an alpha-oxocarboxylate substrate. Enzymatic assays led to the discovery that PA4872 decarboxylates oxaloacetate (kcat = 7500 s(-1) and Km = 2.2 mM) and 3-methyloxaloacetate (kcat = 250 s(-1) and Km = 0.63 mM). Genome context of the fourteen sequence family members indicates that the enzyme is used by select group of Gram-negative bacteria to maintain cellular concentrations of bicarbonate and pyruvate; however the decarboxylation activity cannot be attributed to a pathway common to the various bacterial species.
Droxidopa in neurogenic orthostatic hypotension

PubMed Central

Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto

2015-01-01

Neurogenic orthostatic hypotension (nOH) is a fall in blood pressure on standing due to reduced norepinephrine release from sympathetic nerve terminals. nOH is a feature of several neurological disorders that affect the autonomic nervous system, most notably Parkinson disease (PD), multiple system atrophy, pure autonomic failure and other autonomic neuropathies. Droxidopa, an orally active synthetic amino acid that is converted to norepinephrine by the enzyme aromatic L-amino acid decarboxylase (dopa-decarboxylase), was recently approved by the FDA for the short-term treatment of nOH. It is presumed to raise blood pressure by acting at the neurovascular junction to increase vascular tone. This review summarizes the pharmacological properties of droxidopa, its mechanism of action, and the efficacy and safety results of clinical trials. PMID:26092297
Droxidopa in neurogenic orthostatic hypotension.

PubMed

Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto

2015-01-01

Neurogenic orthostatic hypotension (nOH) is a fall in blood pressure (BP) on standing due to reduced norepinephrine release from sympathetic nerve terminals. nOH is a feature of several neurological disorders that affect the autonomic nervous system, most notably Parkinson disease (PD), multiple system atrophy (MSA), pure autonomic failure (PAF), and other autonomic neuropathies. Droxidopa, an orally active synthetic amino acid that is converted to norepinephrine by the enzyme aromatic L-amino acid decarboxylase (dopa-decarboxylase), was recently approved by the FDA for the short-term treatment of nOH. It is presumed to raise BP by acting at the neurovascular junction to increase vascular tone. This article summarizes the pharmacological properties of droxidopa, its mechanism of action, and the efficacy and safety results of clinical trials.

IR, FT-ICR-MS studies on (1'S, 6'S)-1-cyclopropyl-7-(2,8-diazabicyclo[4.3.0] non-8-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride salt.

PubMed

Lin, Zhiwei

2014-01-01

The infrared spectra of (1'S, 6'S)-1-cyclopropyl-7-(2,8-diazabicyclo[4.3.0] non-8-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride salt (CLF-HCl) were studied and compared with free base. Their fragmentation pathways were investigated using tandem mass spectrometric (MS/MS) techniques on Fourier-transform ion cyclotron resonance spectrum, and many characteristic fragment ions were found. Copyright © 2013 Elsevier B.V. All rights reserved.
Studies on the antibacterial activity of two new acylureidopenicillins, mezlocillin and azlocillin.

PubMed

Soares, L A; Trabulsi, L R

1979-01-01

The antimicrobial activity of 6-[(R)-2[3-methylsulfonyl-2-oxo-imidazolidine-1-carboxamido]-2-phenylacetamido]-penicillanic acid sodium salt (mezlocillin, Baypen) and 6-[(R)-2-(2-oxo-imidazolidine-1-carboxamido)-2-phenylacetamido-a1-penicillanic acid sodium salt (azlocillin, Securopen) was measured against 545 clinical isolates, including gram-negative rods, gram-positive cocci and Bacteroides. Mezlocillin was more effective than azlocillin against the majority of the strains studied, but azlocillin was more effective against Pseudomonas strains. The minimal bactericidal concentration was equal to the minimal inhibitory concentration for the strains tested, but it was twice or four-fold as high for Staphylococcus.
Extracts and Constituents of Rubus chingii with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity

PubMed Central

Ding, Hsiou-Yu

2011-01-01

The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC50 values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC50 values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time. PMID:21747716
Characteristics Of Bridging Oxo And Sulfido Groups In Multinuclear Iron Proteins

NASA Astrophysics Data System (ADS)

Loehr, Thomas M.

1989-07-01

The presence of oxo-bridged dinuclear iron clusters has been established in the respiratory protein, hemerythrin (Hr), and in the DNA-biosynthesis regulatory enzyme, ribonucleotide reductase (Rr). For the iron proteins uteroferrin and purple acid phosphatase (PAP) evidence for μ-oxo-bridged centers is less clear. Resonance Raman (RR) spectra obtained by excitation into an 0(2-) --> Fe(III) CT band may show strong symmetric and weak antisymmetric Fe-0-Fe vibrational modes. We have investigated the spectra of a variety of μ-oxo-bridged Fe(III) complexes to establish the dependence of Raman scattering intensities upon structural parameters. Intensities were found to relate to the nature of the ligand trans to the oxo group: nitrogen ligands with unsaturation (e.g., pyrazole and imidazole) lead to strong scattering, whereas saturated ligands provide only poor scattering. The Fe-0 bonds in Hr and Rr are strong scatterers; the former is known from x-ray crystallography to have a histidyl ligand trans to the μ-oxo group. On this basis, a similar ligand structure is likely in the reductase. In contrast, PAP shows no oxo-bridge with UV and near-UV excitation. We propose that a different structural framework is necessary to account for this result. Hydrogen bonding of protein side chains to oxo and sulfido ligands is proposed to explain changes in frequencies for samples dissolved in water vs. D20. Differences in hydrogen-bond strengths between 0...(D) and S...(D) systems are transferred to the observed Fe-0 and Fe-S bond vibrations.
Short-term dopaminergic regulation of GABA release in dopamine deafferented caudate-putamen is not directly associated with glutamic acid decarboxylase gene expression.

PubMed

O'Connor, W T; Lindefors, N; Brené, S; Herrera-Marschitz, M; Persson, H; Ungerstedt, U

1991-07-08

In vivo microdialysis and in situ hybridization were combined to study dopaminergic regulation of gamma-amino butyric acid (GABA) neurons in rat caudate-putamen (CPu). Potassium-stimulated GABA release in CPu was elevated following a dopamine deafferentation. Local perfusion with exogenous dopamine (50 microM) for 3 h via the microdialysis probe attenuated the potassium-stimulated increase in extracellular GABA in CPu. Expression of glutamic acid decarboxylase (GAD) mRNA was also increased in the dopamine deafferented CPu. However, local perfusion with dopamine had no significant attenuating effect on the increased GAD mRNA expression. These findings indicate that dopaminergic regulation of GABA neurons in the dopamine deafferented CPu includes both a short-term effect at the level of GABA release independent of changes in GAD mRNA expression and a long-term modulation at the level of GAD gene expression.
Immunocytochemical localization of glutamic acid decarboxylase (GAD) and glutamine synthetase (GS) in the area postrema of the cat. Light and electron microscopy

NASA Technical Reports Server (NTRS)

D'Amelio, Fernando E.; Mehler, William R.; Gibbs, Michael A.; Eng, Lawrence F.; Wu, Jang-Yen

1987-01-01

Morphological evidence is presented of the existence of the putative neurotransmitter gamma-aminobutyric acid (GABA) in axon terminals and of glutamine synthetase (GS) in ependymoglial cells and astroglial components of the area postrema (AP) of the cat. Purified antiserum directed against the GABA biosynthetic enzyme glutamic acid decarboxylase (GAD) and GS antiserum were used. The results showed that punctate structures of variable size corresponding to axon terminals exhibited GAD-immunoreactivity and were distributed in varying densities. The greatest accumulation occurred in the caudal and middle segment of the AP and particularly in the area subpostrema, where the aggregation of terminals was extremely dense. The presence of both GAD-immunoreactive profiles and GS-immunostained ependymoglial cells and astrocytes in the AP provide further evidence of the functional correlation between the two enzymes.
Factors affecting the hydroxycinnamate decarboxylase/vinylphenol reductase activity of dekkera/brettanomyces: application for dekkera/brettanomyces control in red wine making.

PubMed

Benito, S; Palomero, F; Morata, A; Calderón, F; Suárez-Lepe, J A

2009-01-01

The growth of Dekkera/Brettanomyces yeasts during the ageing of red wines-which can seriously reduce the quality of the final product-is difficult to control. The present study examines the hydroxycinnamate decarboxylase/vinylphenol reductase activity of different strains of Dekkera bruxellensis and Dekkera anomala under a range of growth-limiting conditions with the aim of finding solutions to this problem. The yeasts were cultured in in-house growth media containing different quantities of growth inhibitors such as ethanol, SO(2), ascorbic acid, benzoic acid and nicostatin, different sugar contents, and at different pHs and temperatures. The reduction of p-coumaric acid and the formation of 4-ethylphenol were periodically monitored by HPLC-PDA. The results of this study allow the optimization of differential media for detecting/culturing these yeasts, and suggest possible ways of controlling these organisms in wineries.
Osmotic Stress-Induced Polyamine Accumulation in Cereal Leaves 1

PubMed Central

Flores, Hector E.; Galston, Arthur W.

1984-01-01

Arginine decarboxylase activity increases 2- to 3-fold in osmotically stressed oat leaves in both light and dark, but putrescine accumulation in the dark is only one-third to one-half of that in light-stressed leaves. If arginine or ornithine are supplied to dark-stressed leaves, putrescine rises to levels comparable to those obtained by incubation under light. Thus, precursor amino acid availability is limiting to the stress response. Amino acid levels change rapidly upon osmotic treatment; notably, glutamic acid decreases with a corresponding rise in glutamine. Difluoromethylarginine (0.01-0.1 millimolar), the enzyme-activated irreversible inhibitor of arginine decarboxylase, prevents the stress-induced putrescine rise, as well as the incorporation of label from [14C]arginine, with the expected accumulation of free arginine, but has no effect on the rest of the amino acid pool. The use of specific inhibitors such as α-difluoromethylarginine is suggested as probes for the physiological significance of stress responses by plant cells. PMID:16663552
Physiological consequences of starvation in Pseudomonas putida: degradation of intracellular protein and loss of activity of the inducible enzymes of L-arginine catabolism.

PubMed

Fan, C L; Rodwell, V W

1975-12-01

We investigated the degradation of radioisotopically labeled intracellular protein in starved, intact cells of Pseudomonas putida P2 (ATCC 25571) and the regulation of this process. Intracellular protein isotopically labeled with L-[4,5-3H]leucine during log-phase growth at 30 C is degraded at rates of 1 to 2%/h in log-phase cells and 7 to 9%/h in starved cells. Rifampin, chloramphenicol, and tosyllysine chloromethylketone lower the rate of protein degradation by starved cells. Addition to starved cells of a nutrient upon which the culture is induced for growth rapidly lowers the rate of protein degradation from 7 to 9%/h to less than 1.5%/h. A nutrient that is oxidized but that cannot immediately support growth also lowers the rate of starvation-induced protein degradation. Proteolytic activity of cell extracts requires a divalent metal ion and may be inhibited up to 60% by tosyllysine chloromethylketone or p-toluenesulfonyl fluoride. Rifampin and chloramphenicol have no effect. In contrast to intact cells, extracts of growing or starving cells degrade protein at equivalent rates. We also investigated the stabilities of the inducible transport system and of four inducible intracellular enzymes of L-arginine catabolism. These include: the membrane-associated, L-arginine-specific transport system; L-arginine oxidase (oxidase); alpha-ketoarginine decarboxylase (decarboxylase); gamma-guanidinobutyraldehyde dehydrogenase ( dehydrogenase); and gamma-guanidinobutyrate amidinohydrolase (hydrolase). In starved cells, the rates of loss of activities were: transport and dehydrogenase activities, stable; oxidase and decarboxylase activities, 20 to 30%/h; hydrolase activity, 5 to 8%/h. Chloramphenicol decreases the rate of loss of oxidase, decarboxylase, and hydrolase activity, whereas p-toluenesulfonyl fluoride lowers the rate of loss of decarboxylase but not of oxidase or hydrolase activity. Addition to starved cells of a nutrient for which they are already induced for growth (e.g., malate, a noninducer of arginine catabolic enzymes) decreases the rate of loss of oxidase and decarboxylase activity but not that of the hydrolase.
A novel approach in acidic disinfection through inhibition of acid resistance mechanisms; Maleic acid-mediated inhibition of glutamate decarboxylase activity enhances acid sensitivity of Listeria monocytogenes.

PubMed

Paudyal, Ranju; Barnes, Ruth H; Karatzas, Kimon Andreas G

2018-02-01

Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L. monocytogenes were investigated and found that it has a higher antimicrobial activity under acidic conditions than other organic acids, while this could not be explained by its pKa or Ka values. The effects were found to be more pronounced on strains with higher GAD activity. Maleic acid affected the extracellular GABA levels while it did not affect the intracellular ones. Maleic acid had a major impact mainly on GadD2 activity as also shown in cell lysates. Furthermore, it was demonstrated that maleic acid is able to partly remove biofilms of L. monocytogenes. Maleic acid is able to inhibit the GAD of L. monocytogenes significantly enhancing its sensitivity to acidic conditions and together with its ability to remove biofilms, make a good candidate for disinfection regimes. Copyright © 2017 Elsevier Ltd. All rights reserved.
21 CFR 172.345 - Folic acid (folacin).

Code of Federal Regulations, 2011 CFR

2011-04-01

... following prescribed conditions: (a) Folic acid is the chemical N-[4-[[(2-amino-1,4-dihydro-4-oxo-6-pteridinyl)methyl]amino]benzoyl]-L-glutamic acid. (b) Folic acid meets the specifications of the “Food... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Folic acid (folacin). 172.345 Section 172.345 Food...
The effects of some polyamine biosynthetic inhibitors on growth and morphology of phytopathogenic fungi

NASA Technical Reports Server (NTRS)

Rajam, M. V.; Galston, A. W.

1985-01-01

We have studied the effects of two polyamine biosynthetic inhibitors, alpha-difluoromethylornithine (DFMO) and alpha-difluoromethylarginine (DFMA), and of polyamines (PAs), alone and in combination, on mycelial growth and morphology of four phytopathogenic fungi: Botrytis sp, B. cinerea, Rhizoctonia solani and Monilinia fructicola. The inhibitors were added to a Czapek agar medium to get final concentrations of 0.1, 0.5 and 1.0 mM. DFMO and DFMA, suicide inhibitors of ornithine decarboxylase (ODC) and arginine decarboxylase (ADC) respectively, inhibited mycelial growth strongly; the effect was generally more pronounced with DFMA than with DFMO, but each fungus had its own response pattern. The addition of the PAs putrescine (Put) and spermidine (Spd) to the culture medium resulted in a promotion of growth. In Botrytis sp and Monilinia fructicola exposed to inhibitors plus PAs, mycelial growth was actually increased above control values. Mycelial morphology was altered and cell size dramatically reduced in plates containing inhibitors alone, whereas with PAs alone, or in combination with inhibitors, morphology was normal, but cell length and diameters increased considerably. These results suggest that PAs are essential for growth in fungal mycelia. The inhibition caused by DFMA may be due to its arginase-mediated conversion to DFMO.
Polyamine levels as related to growth, differentiation and senescence in protoplast-derived cultures of Vigna aconitifolia and Avena sativa

NASA Technical Reports Server (NTRS)

Kaur Sawhney, R.; Shekhawat, N. S.; Galston, A. W.

1985-01-01

We have previously reported that aseptically cultured mesophyll protoplasts of Vigna divide rapidly and regenerate into complete plants, while mesophyll protoplasts of Avena divide only sporadically and senesce rapidly after isolation. We measured polyamine titers in such cultures of Vigna and Avena, to study possible correlations between polyamines and cellular behavior. We also deliberately altered polyamine titer by the use of selective inhibitors of polyamine biosynthesis, noting the effects on internal polyamine titer, cell division activity and regenerative events. In Vigna cultures, levels of free and bound putrescine and spermidine increased dramatically as cell division and differentiation progressed. The increase in bound polyamines was largest in embryoid-forming callus tissue while free polyamine titer was highest in root-forming callus. In Avena cultures, the levels of total polyamines decreased as the protoplast senesced. The presence of the inhibitors alpha-difluoromethyl-arginine (specific inhibitor of arginine decarboxylase), alpha-difluoromethylornithine (specific inhibitor of ornithine decarboxylase) and dicyclohexylamine (inhibitor of spermidine synthase) reduced cell division and organogenesis in Vigna cultures. Addition of low concentration of polyamines to such cultures containing inhibitors or removal of inhibitors from the culture medium restored the progress of growth and differentiation with concomitant increase in polyamine levels.
Maize death acids, 9-lipoxygenase derived cyclopente(a)nones, display activity as cytotoxic phytoalexins and transcriptional mediators

USDA-ARS?s Scientific Manuscript database

Plant damage promotes the interaction of lipoxygenases (LOX) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed jasmonates. ...
Structural insights into the Escherichia coli lysine decarboxylases and molecular determinants of interaction with the AAA+ ATPase RavA

PubMed Central

Kandiah, Eaazhisai; Carriel, Diego; Perard, Julien; Malet, Hélène; Bacia, Maria; Liu, Kaiyin; Chan, Sze W. S.; Houry, Walid A.; Ollagnier de Choudens, Sandrine; Elsen, Sylvie; Gutsche, Irina

2016-01-01

The inducible lysine decarboxylase LdcI is an important enterobacterial acid stress response enzyme whereas LdcC is its close paralogue thought to play mainly a metabolic role. A unique macromolecular cage formed by two decamers of the Escherichia coli LdcI and five hexamers of the AAA+ ATPase RavA was shown to counteract acid stress under starvation. Previously, we proposed a pseudoatomic model of the LdcI-RavA cage based on its cryo-electron microscopy map and crystal structures of an inactive LdcI decamer and a RavA monomer. We now present cryo-electron microscopy 3D reconstructions of the E. coli LdcI and LdcC, and an improved map of the LdcI bound to the LARA domain of RavA, at pH optimal for their enzymatic activity. Comparison with each other and with available structures uncovers differences between LdcI and LdcC explaining why only the acid stress response enzyme is capable of binding RavA. We identify interdomain movements associated with the pH-dependent enzyme activation and with the RavA binding. Multiple sequence alignment coupled to a phylogenetic analysis reveals that certain enterobacteria exert evolutionary pressure on the lysine decarboxylase towards the cage-like assembly with RavA, implying that this complex may have an important function under particular stress conditions. PMID:27080013
GABAA receptor subunit gene expression in human prefrontal cortex: comparison of schizophrenics and controls

NASA Technical Reports Server (NTRS)

Akbarian, S.; Huntsman, M. M.; Kim, J. J.; Tafazzoli, A.; Potkin, S. G.; Bunney, W. E. Jr; Jones, E. G.; Bloom, F. E. (Principal Investigator)

1995-01-01

The prefrontal cortex of schizophrenics is hypoactive and displays changes related to inhibitory, GABAergic neurons, and GABAergic synapses. These changes include decreased levels of glutamic acid decarboxylase (GAD), the enzyme for GABA synthesis, upregulation of muscimol binding, and downregulation of benzodiazepine binding to GABAA receptors. Studies in the visual cortex of nonhuman primates have demonstrated that gene expression for GAD and for several GABAA receptor subunit polypeptides is under control of neuronal activity, raising the possibility that similar mechanisms in the hypoactive prefrontal cortex of schizophrenics may explain the abnormalities in GAD and in GABAA receptor regulation. In the present study, which is the first of its type on human cerebral cortex, levels of mRNAs for six GABAA receptor subunits (alpha 1, alpha 2, alpha 5, beta 1, beta 2, gamma 2) and their laminar expression patterns were analyzed in the prefrontal cortex of schizophrenics and matched controls, using in situ hybridization histochemistry and densitometry. Three types of laminar expression pattern were observed: mRNAs for the alpha 1, beta 2, and gamma 2 subunits, which are the predominant receptor subunits expressed in the mature cortex, were expressed at comparatively high levels by cells of all six cortical layers, but most intensely by cells in lower layer III and layer IV. mRNAs for the alpha 2, alpha 5, and beta 1 subunits were expressed at lower levels; alpha 2 and beta 1 were expressed predominantly by cells in layers II, III, and IV; alpha 5 was expressed predominantly in layers IV, V, and VI. There were no significant changes in overall mRNA levels for any of the receptor subunits in the prefrontal cortex of schizophrenics, and the laminar expression pattern of all six receptor subunit mRNAs did not differ between schizophrenics and controls. Because gene expression for GABAA receptor subunits is not consistently altered in the prefrontal cortex of schizophrenics, the previously reported upregulation of muscimol binding sites and downregulation of benzodiazepine binding sites in the prefrontal and adjacent cingulate cortex of schizophrenics are possibly due to posttranscriptional modifications of mRNAs and their translated polypeptides.
The metabolism and pharmacokinetics of isotretinoin in patients with acne and rosacea are not influenced by ethanol.

PubMed

Grønhøj Larsen, F; Jakobsen, P; Grønhøj Larsen, C; Heidenheim, M; Held, E; Nielsen-Kudsk, F

2009-09-01

Isotretinoin is effective in the treatment of severe acne and rosacea. Both parent drug and its main metabolite 4-oxo-isotretinoin are potentially teratogenic compounds and contain a carboxylic acid moiety. In the presence of ethanol, naturally occurring as well as synthetic retinoids also containing a carboxylic acid moiety are capable of undergoing an ethyl esterification with the metabolic formation of more lipophilic compounds with a much longer terminal half-life. To determine if isotretinoin (13-cis-RA), its main metabolite 4-oxo-isotretinoin (4-oxo-13-cis-RA), and other possible metabolites in the presence or absence of ethanol are converted to their corresponding ethyl derivatives in patients with severe acne or rosacea after multiple isotretinoin dosing. In addition, pharmacokinetic parameters of the parent drug and its 4-oxo metabolite were determined. Eleven patients with severe acne or rosacea were treated with isotretinoin daily for 3 months and investigated pharmacokinetically during 24 h after 1 month of treatment and for up to 28 days after discontinuation of therapy. A possible influence of ethanol was evaluated using a simple self-administered questionnaire and by measuring serum ethanol levels during treatment. The concentrations of isotretinoin, 4-oxo-isotretinoin and possible ethylated and nonethylated metabolites were measured by reverse-phase high-performance liquid chromatography. Although seven of 11 patients had a considerable weekly alcohol intake, no endogenous synthesis of ethyl derivatives of isotretinoin, the main 4-oxo metabolite or the all-trans compounds was chromatographically detectable in any of the patients' plasma samples during the treatment period. Multiple dose pharmacokinetic data for the parent drug and its main metabolite were comparable to previous studies. The metabolism and pharmacokinetics of isotretinoin and its main metabolites are not influenced by ethanol during long-term isotretinoin treatment. After ceasing long-term isotretinoin therapy the recommended period of 1 month for using anticonceptive measures in fertile women seems adequate.
Dual mechanisms regulating glutamate decarboxylases and accumulation of gamma-aminobutyric acid in tea (Camellia sinensis) leaves exposed to multiple stresses

PubMed Central

Mei, Xin; Chen, Yiyong; Zhang, Lingyun; Fu, Xiumin; Wei, Qing; Grierson, Don; Zhou, Ying; Huang, Yahui; Dong, Fang; Yang, Ziyin

2016-01-01

γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. It has multiple positive effects on mammalian physiology and is an important bioactive component of tea (Camellia sinensis). GABA generally occurs at a very low level in plants but GABA content increases substantially after exposure to a range of stresses, especially oxygen-deficiency. During processing of tea leaves, a combination of anoxic stress and mechanical damage are essential for the high accumulation of GABA. This is believed to be initiated by a change in glutamate decarboxylase activity, but the underlying mechanisms are unclear. In the present study we characterized factors regulating the expression and activity of three tea glutamate decarboxylase genes (CsGAD1, 2, and 3), and their encoded enzymes. The results suggests that, unlike the model plant Arabidopsis thaliana, there are dual mechanisms regulating the accumulation of GABA in tea leaves exposed to multiple stresses, including activation of CsGAD1 enzymatic activity by calmodulin upon the onset of the stress and accumulation of high levels of CsGAD2 mRNA induced by a combination of anoxic stress and mechanical damage. PMID:27021285
Dual mechanisms regulating glutamate decarboxylases and accumulation of gamma-aminobutyric acid in tea (Camellia sinensis) leaves exposed to multiple stresses.

PubMed

Mei, Xin; Chen, Yiyong; Zhang, Lingyun; Fu, Xiumin; Wei, Qing; Grierson, Don; Zhou, Ying; Huang, Yahui; Dong, Fang; Yang, Ziyin

2016-03-29

γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. It has multiple positive effects on mammalian physiology and is an important bioactive component of tea (Camellia sinensis). GABA generally occurs at a very low level in plants but GABA content increases substantially after exposure to a range of stresses, especially oxygen-deficiency. During processing of tea leaves, a combination of anoxic stress and mechanical damage are essential for the high accumulation of GABA. This is believed to be initiated by a change in glutamate decarboxylase activity, but the underlying mechanisms are unclear. In the present study we characterized factors regulating the expression and activity of three tea glutamate decarboxylase genes (CsGAD1, 2, and 3), and their encoded enzymes. The results suggests that, unlike the model plant Arabidopsis thaliana, there are dual mechanisms regulating the accumulation of GABA in tea leaves exposed to multiple stresses, including activation of CsGAD1 enzymatic activity by calmodulin upon the onset of the stress and accumulation of high levels of CsGAD2 mRNA induced by a combination of anoxic stress and mechanical damage.
Microbial hydroxylation and glycosidation of oleanolic acid by Circinella muscae and their anti-inflammatory activities.

PubMed

Yan, Sensen; Lin, Haijun; Huang, Huilian; Yang, Min; Xu, Bohui; Chen, Guangtong

2018-05-29

Biotransformation of oleanolic acid (OA) by Circinella muscae AS 3.2695 was investigated. Nine hydroxylated and glycosylated metabolites (1-9) were obtained. Their structures were elucidated as 3β,7β-dihydroxyolean-12-en-28-oic acid (1), 3β,7β,21β-trihydroxyolean-12-en-28-oic acid (2), 3β,7α,21β-trihydroxyolean-12-en- 28-oic acid (3), 3β,7β,15α-trihydroxyolean-12-en-28-oic acid (4), 7β,15α-dihydroxy- 3-oxo-olean-12-en-28-oic acid (5), 7β-hydroxy-3-oxo-olean-12-en-28-oic acid (6), oleanolic acid-28-O-β-D-glucopyranosyl ester (7), 3β,21β-dihydroxyolean-12-en-28- oic acid-28-O-β-D-glucopyranosyl ester (8), and 3β,7β,15α-trihydroxyolean-12-en- 28-oic acid-28-O-β-D-glucopyranosyl ester (9) by spectroscopic analysis. Among them, compounds 4 and 9 were new compounds. In addition, anti-inflammatory activities were assayed and evaluated for the isolated metabolites. Most of the metabolites exhibited significant inhibitory activities on lipopolysaccharides-induced NO production in RAW 264.7 cells.

Downbeating nystagmus and muscle spasms in a patient with glutamic-acid decarboxylase antibodies.

PubMed

Ances, Beau M; Dalmau, Josep O; Tsai, Jean; Hasbani, M Josh; Galetta, Steven L

2005-07-01

To report the ophthalmic findings and response to treatment in a patient with glutamic-acid decarboxylase antibodies. Case report. A 55-year-old woman developed progressive, painful, low back muscle spasms, vertical diplopia, downbeating nystagmus, and asymmetric appendicular ataxia. Downbeating nystagmus was present in primary gaze with an alternating skew deviation in lateral gaze. Serum and cerebrospinal fluid GAD antibodies were detected. Treatment with diazepam led to resolution of spasticity, whereas repeated courses of intravenous immunoglobulin improved cerebellar function, including appendicular ataxia and downbeating nystagmus. Patients with GAD antibodies may have elements of both Stiff-person syndrome (muscle rigidity and spasms) and prominent cerebellar dysfunction. Treatment with diazepam rapidly improved Stiff-person symptoms, whereas IVIg was partially effective at the early stage of cerebellar dysfunction.
Postpartum changes in the GABAergic system in the bed nucleus of the accessory olfactory tract.

PubMed

Rodríguez, Cilia; Guillamón, Antonio; Pinos, Helena; Collado, Paloma

2004-02-01

The bed nucleus of the accessory olfactory tract (BAOT) is a sexually dimorphic structure which controls the inhibition/disinhibition of the medial preoptic area in the expression of maternal behavior. Therefore, in the present study we investigated sex differences and the modulation of gamma-aminobutiric-acid (GABA) in the BAOT during the first two postpartum days. Four groups of Wistar rats: control males, control females, 0 h postpartum females and 48 h postpartum females, were used in this experiment. Sex differences in glutamate decarboxylase (GAD) and GABA(A) alpha-chain receptor densities were apparent in the BAOT. The hormonal and behavioral postpartum state affects GABAergic activity in the females' BAOT in two ways: firstly, pregnancy and the first two postpartum days induce an increase in GABA(A)-receptor and GAD densities; secondly, the intensity of these activities are greater in the left hemisphere than in the right. These changes might be related to the BAOT's function of inhibiting/disinhibiting maternal behavior.
In vitro evaluation of the safety and probiotic properties of Lactobacilli isolated from chicken and calves.

PubMed

Bujnakova, Dobroslava; Strakova, Eva; Kmet, Vladimir

2014-10-01

A total of 73 chicken and calves isolates were diagnosed using matrix-assisted laser desorption ionization-time-of flight mass spectrometry (Maldi-Tof MS). After a preliminary subtractive screening based on the high acid tolerance at pH 2.5 and bile resistance at 0.3% oxgall, twenty isolates belonging to the species Lactobacillus salivarius, Lactobacillus agilis, Lactobacillus reuteri, Lactobacillus murinus and Lactobacillus amylovorus were in vitro screened for the safety assessment and probiotic properties, including antibiotics susceptibility patterns, biochemical activity and potential for competitive exclusion of biofilm producing pathogens determined by crystal violet and/or quantitative Fluorescent in situ Hybridisation (FISH) assays utilizing 5'Cy 3 labelled probe Enter1432 for enteric group. Antibiotic susceptibility testing was performed according to the ISO norm 10932. The sixteen strains were susceptible to certain antimicrobial agents, except for two chicken (L. salivarius 12K, L. agilis 13K) and two calves (L. reuteri L10/1, L. murinus L9) isolates with the presence non wild-type ECOFFs (epidemiological cut-off) for gentamicin (≥256 μg ml(-1)), tetracycline (≥128 μg ml(-1)), kanamycin (≥256 μg ml(-1)) and streptomycin (≥96 μg ml(-1)). The two referenced chicken isolates gave positive aac(6')Ie-aph(2″)Ia and tet(L) PCR results. The wild-type ECOFFs isolates were subjected to the apiZYM analysis for enzyme profile evaluation and amino acid decarboxylase activities determined by qualitative plate method and multiplex PCR for the detection of four genes involved in the production of histamine (histidine decarboxylase, hdc), tyramine (tyrosine decarboxylase, tyrdc) and putrescine (via eithers ornithine decarboxylase, odc, or agmatine deiminase, agdi). From examined strains only two chicken isolates (L. reuteri 14K; L. salivarius 15K) had no harmful β-glucuronidase, β-glucosidase activities connected with detrimental effects in the gastrointestinal tract and together no amino acid decarboxylase activities and no genes associated with biogenic amines production though only chicken L. salivarius 15K whole cells and acid supernatants shown strong suppressive potential against biofilm-forming Klebsiella and Escherichia coli. Our results highlight that above-mentioned isolate L. salivarius 15K fulfils the principle requirements of a qualified probiotic and may be seen as a reliable candidate for further validation studies in chicken. Copyright © 2013 Elsevier Ltd. All rights reserved.
10-Oxo-trans-11-octadecenoic acid generated from linoleic acid by a gut lactic acid bacterium Lactobacillus plantarum is cytoprotective against oxidative stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Furumoto, Hidehiro; Nanthirudjanar, Tharnath; Kume, Toshiaki

Oxidative stress is a well-known cause of multiple diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway plays a central role in cellular antioxidative responses. In this study, we investigated the effects of novel fatty acid metabolite derivatives of linoleic acid generated by the gut lactic acid bacteria Lactobacillus plantarum on the Nrf2-ARE pathway. 10-Oxo-trans-11-octadecenoic acid (KetoC) protected HepG2 cells from cytotoxicity induced by hydrogen peroxide. KetoC also significantly increased cellular Nrf2 protein levels, ARE-dependent transcription, and the gene expression of antioxidative enzymes such as heme oxygenase-1 (HO-1), glutamate-cysteine ligase modifier subunit (GCLM), and NAD(P)H:quinone oxidoreductasemore » 1 (NQO1) in HepG2 cells. Additionally, a single oral dose administration of KetoC also increased antioxidative gene expression and protein levels of Nrf2 and HO-1 in mouse organs. Since other fatty acid metabolites and linoleic acid did not affect cellular antioxidative responses, the cytoprotective effect of KetoC may be because of its α,β-unsaturated carbonyl moiety. Collectively, our data suggested that KetoC activated the Nrf2-ARE pathway to enhance cellular antioxidative responses in vitro and in vivo, which further suggests that KetoC may prevent multiple diseases induced by oxidative stress. - Highlights: • We evaluated the effect of modified fatty acids generated by Lactobacillus plantarum. • 10-Oxo-trans-11-ocatadecenoic acid (KetoC) protected cells from oxidative stress. • KetoC activated the Nrf2-ARE pathway to promote antioxidative gene expression. • KetoC promoted the expression of antioxidative enzymes in mice organs. • The cytoprotective effect of KetoC was because of α,β-unsaturated carbonyl moiety.« less
10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp; Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University; Kim, Young-Il

2015-04-17

Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increasedmore » adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.« less
Diethylglyoxal bis(guanylhydrazone): a novel highly potent inhibitor of S-adenosylmethionine decarboxylase with promising properties for potential chemotherapeutic use.

PubMed

Elo, H; Mutikainen, I; Alhonen-Hongisto, L; Laine, R; Jänne, J

1988-07-01

Diethylglyoxal bis(guanylhydrazone) (DEGBG), a novel analog of the antileukemic agent methylglyoxal bis(guanylhydrazone) (MGBG) was synthesized. It was found to be the most powerful inhibitor of yeast S-adenosylmethionine decarboxylase (AdoMetDC) so far studied (Ki approx. 9 nM). This property, together with the finding that the compound is a weaker inhibitor of intestinal diamine oxidase than are MGBG and its glyoxal, ethylglyoxal and ethylmethylglyoxal analogs, makes the compound a promising candidate as a polyamine antimetabolite for chemotherapy studies. DEGBG was also found to potentiate the antiproliferative effect of the ornithine decarboxylase inhibitor alpha-difluoromethyl ornithine against mouse L1210 leukemia cells in vitro. DEGBG increased several-fold the intracellular putrescine concentration of cultured L1210 cells, just as MGBG and its ethylglyoxal analog are known to do. The results strongly suggest that DEGBG is worth further studies. Combined with previous studies, they also made possible the construction of some empirical rules concerning the structure-activity relationships of bis(guanylhydrazone) type inhibitors of AdoMetDC. The identity of DEGBG was confirmed by a single-crystal X-ray analysis and by 1H- and 13C-NMR spectroscopy. It consisted of the same isomer as MGBG and several of its analogs are known to consist of.
Maize death acids, 9-lipoxygenase-derived cyclopente(a)nones display activity as cytotoxic phytoalexins and transcriptional mediators

USDA-ARS?s Scientific Manuscript database

Plant cellular damage promotes the interaction of lipoxygenases (LOX) with free fatty acids to yield 9- and 13-hydroperoxides which are further metabolized into diverse oxylipins. The enzymatic action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downst...
Molecular mechanisms by which oxidative DNA damage promotes telomerase activity.

PubMed

Lee, Hui-Ting; Bose, Arindam; Lee, Chun-Ying; Opresko, Patricia L; Myong, Sua

2017-11-16

Telomeres are highly susceptible to oxidative DNA damage, which if left unrepaired can lead to dysregulation of telomere length homeostasis. Here we employed single molecule FRET, single molecule pull-down and biochemical analysis to investigate how the most common oxidative DNA lesions, 8-oxoguanine (8oxoG) and thymine glycol (Tg), regulate the structural properties of telomeric DNA and telomerase extension activity. In contrast to 8oxoG which disrupts the telomeric DNA structure, Tg exhibits substantially reduced perturbation of G-quadruplex folding. As a result, 8oxoG induces high accessibility, whereas Tg retains limited accessibility, of telomeric G-quadruplex DNA to complementary single stranded DNA and to telomere binding protein POT1. Surprisingly, the Tg lesion stimulates telomerase loading and activity to a similar degree as an 8oxoG lesion. We demonstrate that this unexpected stimulation arises from Tg-induced conformational alterations and dynamics in telomeric DNA. Despite impacting structure by different mechanisms, both 8oxoG and Tg enhance telomerase binding and extension activity to the same degree, potentially contributing to oncogenesis. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.
Organic reactions catalyzed by methylrhenium trioxide: Reactions of ethyl diazoacetate and organic azides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Z.; Espenson, J.H.

1996-10-16

Methylrhenium trioxide (CH{sub 3}ReO{sub 3} or MTO) catalyzes several classes of reactions of ethyl diazoacetate, EDA. It is the first high valent oxo complex for carbene transfer. Under mild conditions and in the absence of other substrates, EDA was converted to a 9:1 mixture of diethyl maleate and diethyl fumarate. In the presence of alcohols, {alpha}-alkoxy ethyl acetates were obtained in good yield. The yields dropped for the larger and more branched alcohols, the balance of material being diethyl maleate and fumarate. An electron-donating group in the para position of phenols favors the formation of {alpha}-phenoxy ethyl acetates. The usemore » of EDA to form {alpha}-thio ethyl acetates and N-substituted glycine ethyl esters, on the other hand, is hardly affected by the size or structure of the parent thiol or amine, with all of these reactions proceeding in high yield. MTO-catalyzed cycloaddition reactions occur between EDA and aromatic imines, olefins, and carbonyl compounds. Three-membered ring products are formed: aziridines, cyclopropanes, and epoxides, respectively. The reactions favor the formation of trans products, and provide a convenient route for the preparation of aziridines. Intermediate carbenoid and nitrenoid species have been proposed. In the presence of an oxygen source such as an epoxide, ethyl diazoacetate and azibenzil are converted to an oxalic acid monoethyl ester and to benzil; at the same time the epoxide was converted to an olefin. 75 refs., 1 fig., 7 tabs.« less
Gene cloning, recombinant expression, purification and characterization of l-methionine decarboxylase from Streptomyces sp. 590.

PubMed

Hayashi, Masaya; Okada, Akane; Yamamoto, Kumiko; Okugochi, Tomomi; Kusaka, Chika; Kudou, Daizou; Nemoto, Michiko; Inagaki, Junko; Hirose, Yuu; Okajima, Toshihide; Tamura, Takashi; Soda, Kenji; Inagaki, Kenji

2017-04-01

l-Methionine decarboxylase (MetDC) from Streptomyces sp. 590 depends on pyridoxal 5'-phosphate and catalyzes the non-oxidative decarboxylation of l-methionine to produce 3-methylthiopropylamine and carbon dioxide. MetDC gene (mdc) was determined to consist of 1,674 bp encoding 557 amino acids, and the amino acid sequence is similar to that of l-histidine decarboxylases and l-valine decarboxylases from Streptomyces sp. strains. The mdc gene was cloned and recombinant MetDC was heterologously expressed by Escherichia coli. The purification of recombinant MetDC was carried out by DEAE-Toyopearl and Ni-NTA agarose column chromatography. The recombinant enzyme was homodimeric with a molecular mass of 61,000 Da and showed optimal activity between 45 to 55 °C and at pH 6.6, and the stability below 30 °C and between pH 4.6 to 7.0. l-Methionine and l-norleucine were good substrates for MetDC. The Michaelis constants for l-methionine and l-norleucine were 30 and 73 mM, respectively. The recombinant MetDC (0.50 U/ml) severely inhibited growth of human tumour cells A431 (epidermoid ovarian carcinoma cell line) and MDA-MB-231 (breast cancer cell line), however showed relatively low cytotoxicity for human normal cell NHDF-Neo (dermal fibroblast cell line from neonatal foreskin). This study revealed the properties of the gene and the protein sequence of MetDC for the first time. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.
The speEspeD operon of Escherichia coli. Formation and processing of a proenzyme form of S-adenosylmethionine decarboxylase.

PubMed

Tabor, C W; Tabor, H

1987-11-25

We have previously shown that the gene (speD) for S-adenosylmethionine decarboxylase is part of an operon that also contains the gene (speE) for spermidine synthase (Tabor, C. W., Tabor, H., and Xie, Q.-W. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 6040-6044). We have now determined the nucleotide sequence of this operon and have found that speD codes for a polypeptide of Mr = 30,400, which is considerably greater than the subunit size of the purified enzyme. Our studies show that S-adenosylmethionine decarboxylase is first formed as a Mr = 30,400 polypeptide and that this proenzyme is then cleaved at the Lys111-Ser112 peptide bond to form a Mr = 12,400 subunit and a Mr = 18,000 subunit. The latter subunit contains the pyruvoyl moiety that we previously showed is required for enzymatic activity. Both subunits are present in the purified enzyme. These conclusions are based on (i) pulse-chase experiments with a strain containing a speD+ plasmid which showed a precursor-product relationship between the proenzyme and the enzyme subunits, (ii) the amino acid sequence of the proenzyme form of S-adenosylmethionine decarboxylase (derived from the nucleotide sequence of the speD gene), and (iii) comparison of this sequence of the proenzyme with the N-terminal amino acid sequences of the two subunits of the purified enzyme reported by Anton and Kutny (Anton, D. L., and Kutny, R. (1987) J. Biol. Chem. 262, 2817-2822).
Modelling the cis-oxo-labile binding site motif of non-heme iron oxygenases. Water exchange and remarkable oxidation reactivity of a novel non-heme iron(IV)-oxo compound bearing a tripodal tetradentate ligand

PubMed Central

Company, Anna; Prat, Irene; Frisch, Jonathan R.; Ballesté, Ruben Mas; Güell, Mireia; Juhász, Gergely; Ribas, Xavi; Münck, Eckard; Luis, Josep M.; Que, Lawrence

2011-01-01

The spectroscopic and chemical characterization of a new synthetic non-heme iron(IV)-oxo species [FeIV(O)(Me,HPytacn)(S)]2+ (2, Me,HPytacn = 1-(2′-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane, S = CH3CN or H2O) is described. 2 has been prepared by reaction of [FeII(CF3SO3)2(Me,HPytacn)] (1) with peracetic acid. Complex 2 bears a tetradentate N4 ligand that leaves two cis- sites available for binding an oxo group and a second external ligand but, unlike related iron(IV)-oxo of tetradentate ligands, it is remarkably stable at room temperature (t1/2 > 2h at 288 K). Its ability to exchange the oxygen atom of the oxo ligand with water has been analyzed in detail by means of kinetic studies, and a mechanism has been proposed on the basis of DFT calculations. Hydrogen-atom abstraction from C-H bonds and oxygen atom transfer to sulfides by 2 have also been studied. Despite its thermal stability, 2 proves to be a very powerful oxidant that is capable of breaking the strong C-H bond of cyclohexane (BDE = 99.3 kcal·mol−1). PMID:21268165
Novel oligorhamnosides from the stem bark of Cleistopholis glauca.

PubMed

Seidel, V; Bailleul, F; Waterman, P G

2000-01-01

A reinvestigation of the stem bark of Cleistopholis glauca yielded 14 compounds, of which seven were either novel or had not been previously reported from this species. These were identified as the farnesane sesquiterpene methyl-(2E,6E)-10-oxo-3,7, 11-trimethyl-dodeca-2,6-dienoate (1); the azaanthracene alkaloid cleistopholine (4); two partially acetylated oligorhamnoside derivatives, 1-O-dodecanyl-2,3, 4-tri-O-acetyl-alpha-rhamnopyranosyl-(1-->3)-2, 4-di-O-acetyl-alpha-rhamnopyranosyl-(1-->3)-4-O-acetyl-alpha-rhamnopy ranosyl-(1-->4)-alpha-rhamnopyranoside (6) and 1-O-dodecanyl-2, 4-di-O-acetyl-alpha-rhamnopyranosyl-(1-->3)-2, 4-di-O-acetyl-alpha-rhamnopyranosyl-(1-->3)-4-O-acetyl-alpha-rhamnopy ranosyl-(1-->4)-alpha-rhamnopyranoside (8), for which the trivial names cleistetroside-7 and cleistetroside-6 were assigned, respectively; the dihydrobenzofuran neolignan rel-(2alpha, 3beta)-7-O-methylcedrusin (12); and the flavonoids dihydroquercetin (13) and quercetin (14). Structure assignments of all compounds were established by spectroscopic methods and comparison with published data. The chemosystematic significance of the occurrence of the isolated components is mentioned. Compounds 1, 6, and 8 are novel natural products.
The X-ray structure of Paramecium bursaria Chlorella virus arginine decarboxylase: insight into the structural basis for substrate specificity

PubMed Central

Shah, Rahul; Akella, Radha; Goldsmith, Elizabeth J.; Phillips, Margaret A.

2008-01-01

The group IV pyridoxal-5′-phosphate (PLP)-dependent decarboxylases belong to the β/α barrel structural family, and include enzymes with substrate specificity for a range of basic amino acids. A unique homolog of this family, the Paramecium bursaria Chlorella virus arginine decarboxylase (cvADC), shares about 40% amino acid sequence identity with the eukaryotic ornithine decarboxylases (ODCs). The X-ray structure of cvADC has been solved to 1.95 and 1.8 Å resolution for the free and agmatine (product)-bound enzymes. The global structural differences between cvADC and eukaryotic ODC are minimal (rmsd of 1.2 – 1.4 Å), however, the active site has significant structural rearrangements. The key “specificity element,” is identified as the 310-helix that contains and positions substrate-binding residues such as E296 cvADC (D332 in T. brucei ODC). In comparison to the ODC structures, the 310-helix in cvADC is shifted over 2 Å away from the PLP cofactor, thus accommodating the larger arginine substrate. Within the context of this conserved fold, the protein is designed to be flexible in the positioning and amino acid sequence of the 310-helix, providing a mechanism to evolve different substrate preferences within the family without large structural rearrangements. Also, in the structure, the “K148-loop” (homologous to the “K169-loop” of ODC) is observed in a closed, substrate-bound conformation for the first time. Apparently the K148 loop is a mobile loop, analogous to those observed in triose phosphate isomerase and tryptophan synthetase. In conjunction with prior structural studies these data predict that this loop adopts different conformations throughout the catalytic cycle, and that loop movement may be kinetically linked to the rate-limiting step of product release. PMID:17305368
Role of UDP-glucuronosyltransferase isoforms in 13-cis retinoic acid metabolism in humans.

PubMed

Rowbotham, Sophie E; Illingworth, Nicola A; Daly, Ann K; Veal, Gareth J; Boddy, Alan V

2010-07-01

13-cis Retinoic acid (13cisRA, isotretinoin) is an important drug in both dermatology, and the treatment of high-risk neuroblastoma. 13cisRA is known to undergo cytochrome P450-mediated oxidation, mainly by CYP2C8, but phase II metabolic pathways have not been characterized. In the present study, the glucuronidation activities of human liver (HLM) and intestinal microsomes (HIM), as well as a panel of human UDP-glucuronosyltransferases (UGTs) toward both 13cisRA and the 4-oxo metabolite, 4-oxo 13cisRA, were compared using high-performance liquid chromatography. Both HLM and, to a greater extent, HIM catalyzed the glucuronidation of 13cisRA and 4-oxo 13cisRA. Based on the structures of 13cisRA and 4-oxo 13cisRA, the glucuronides formed are conjugated at the terminal carboxylic acid. Further analysis revealed that UGT1A1, UGT1A3, UGT1A7, UGT1A8, and UGT1A9 were the major isoforms responsible for the glucuronidation of both substrates. For 13cisRA, a pronounced substrate inhibition was observed with individual UGTs and with HIM. UGT1A3 exhibited the highest rate of activity toward both substrates, and a high rate of activity toward 13cisRA glucuronidation was also observed with UGT1A7. However, for both substrates, K(m) values were above concentrations reported in clinical studies. Therefore, UGT1A9 is likely to be the most important enzyme in the glucuronidation of both substrates as this enzyme had the lowest K(m) and is expressed in both the intestine and at high levels in the liver.
Ion-Size-Dependent Formation of Mixed Titanium/Lanthanide Oxo Clusters.

PubMed

Artner, Christine; Kronister, Stefan; Czakler, Matthias; Schubert, Ulrich

2014-11-01

The mixed-metal oxo clusters LnTi 4 O 3 (O i Pr) 2 (OMc) 11 (Ln = La, Ce; OMc = methacrylate), Ln 2 Ti 6 O 6 (OMc) 18 (HO i Pr) (Ln = La, Ce, Nd, Sm) and Ln 2 Ti 4 O 4 (OMc) 14 (HOMc) 2 (Ln = Sm, Eu, Gd, Ho) have been synthesized from titanium isopropoxide, the corresponding lanthanide acetate and methacrylic acid. The type of cluster obtained strongly depends on the size of the lanthanide ion.
Glutamate and GABA-metabolizing enzymes in post-mortem cerebellum in Alzheimer's disease: phosphate-activated glutaminase and glutamic acid decarboxylase.

PubMed

Burbaeva, G Sh; Boksha, I S; Tereshkina, E B; Savushkina, O K; Prokhorova, T A; Vorobyeva, E A

2014-10-01

Enzymes of glutamate and GABA metabolism in postmortem cerebellum from patients with Alzheimer's disease (AD) have not been comprehensively studied. The present work reports results of original comparative study on levels of phosphate-activated glutaminase (PAG) and glutamic acid decarboxylase isoenzymes (GAD65/67) in autopsied cerebellum samples from AD patients and matched controls (13 cases in each group) as well as summarizes published evidence for altered levels of PAG and GAD65/67 in AD brain. Altered (decreased) levels of these enzymes and changes in links between amounts of these enzymes and other glutamate-metabolizing enzymes (such as glutamate dehydrogenase and glutamine synthetase-like protein) in AD cerebella suggest significantly impaired glutamate and GABA metabolism in this brain region, which was previously regarded as not substantially involved in AD pathogenesis.
The influence of NaCl on hydrophobicity of selected, pharmacologically active bile acids expressed with chromatographic retention index and critical micellar concentration.

PubMed

Posa, Mihalj; Pilipović, Ana; Lalić, Mladena

2010-11-01

Many of bile acids' (BA) physiological properties, as receptor binding, activation of ionic channels, binding to blood proteins, etc. are due to their hydrophobicity. On the other hand, hydrophobicity determines BAs' physico-chemical characteristics as micelle forming and adsorption (surface activity). However, BA hydrophobicity is not determined solely by their structure. Medium composition, especially the concentration of electrolytes has influence on BA hydrophobicity. Thus, the objective of this work was to examine the effect of NaCl on hydrophobicity of selected bile acids. This influence is specified with the retention factor k (reversed phase high pressure liquid chromatography (RPHPLC)) and critical micellar concentration (CMC) determined by non-invasive NMR method. The value of lnk elevates with the increase in mobile phase NaCl concentration i.e. Deltalnk/Deltac(NaCl) depends on the number of water molecules not stabilised by hydrogen bonds in bile acid hydration sheath. For bile acids that contain hydroxyl groups (except those with beta equatorial hydroxyl groups) the value of |DeltalnCMC/Deltac(NaCl)| rises with the increase in the number of non-stabilized water molecules in their hydration sheath. Even though oxo derivatives of cholic acid have similar chromatographic parameters they behave differently when it comes to CMC. In fact with the introduction of oxo groups the value of its |DeltalnCMC/Deltac(NaCl)| elevates but it results in a decrease in the number of non-stabilized water molecules i.e. hydrophobicity falls. Different behaviour of oxo derivatives implicate that, besides "hydrophobic interactions" in their micelles, there are also hydrogen bonds i.e. fiord effect exists. Copyright (c) 2010 Elsevier B.V. All rights reserved.
Role of a Modulator in the Synthesis of Phase-Pure NU-1000.

PubMed

Webber, Thomas E; Liu, Wei-Guang; Desai, Sai Puneet; Lu, Connie C; Truhlar, Donald G; Penn, R Lee

2017-11-15

NU-1000 is a robust, mesoporous metal-organic framework (MOF) with hexazirconium nodes ([Zr 6 O 16 H 16 ] 8+ , referred to as oxo-Zr 6 nodes) that can be synthesized by combining a solution of ZrOCl 2 ·8H 2 O and a benzoic acid modulator in N,N-dimethylformamide with a solution of linker (1,3,6,8-tetrakis(p-benzoic acid)pyrene, referred to as H 4 TBAPy) and by aging at an elevated temperature. Typically, the resulting crystals are primarily composed of NU-1000 domains that crystallize with a more dense phase that shares structural similarity with NU-901, which is an MOF composed of the same linker molecules and nodes. Density differences between the two polymorphs arise from the differences in the node orientation: in NU-1000, the oxo-Zr 6 nodes rotate 120° from node to node, whereas in NU-901, all nodes are aligned in parallel. Considering this structural difference leads to the hypothesis that changing the modulator from benzoic acid to a larger and more rigid biphenyl-4-carboxylic acid might lead to a stronger steric interaction between the modulator coordinating on the oxo-Zr 6 node and misaligned nodes or linkers in the large pore and inhibit the growth of the more dense NU-901-like material, resulting in phase-pure NU-1000. Side-by-side reactions comparing the products of synthesis using benzoic acid or biphenyl-4-carboxylic acid as a modulator produce structurally heterogeneous crystals and phase-pure NU-1000 crystals. It can be concluded that the larger and more rigid biphenyl-4-carboxylate inhibits the incorporation of nodes with an alignment parallel to the neighboring nodes already residing in the crystal.
Sequence of the cDNA of a human dihydrodiol dehydrogenase isoform (AKR1C2) and tissue distribution of its mRNA.

PubMed Central

Shiraishi, H; Ishikura, S; Matsuura, K; Deyashiki, Y; Ninomiya, M; Sakai, S; Hara, A

1998-01-01

Human liver contains three isoforms (DD1, DD2 and DD4) of dihydrodiol dehydrogenase with 20alpha- or 3alpha-hydroxysteroid dehydrogenase activity; the dehydrogenases belong to the aldo-oxo reductase (AKR) superfamily. cDNA species encoding DD1 and DD4 have been identified. However, four cDNA species with more than 99% sequence identity have been cloned and are compatible with a partial amino acid sequence of DD2. In this study we have isolated a cDNA clone encoding DD2, which was confirmed by comparison of the properties of the recombinant and hepatic enzymes. This cDNA showed differences of one, two, four and five nucleotides from the previously reported four cDNA species for a dehydrogenase of human colon carcinoma HT29 cells, human prostatic 3alpha-hydroxysteroid dehydrogenase, a human liver 3alpha-hydroxysteroid dehydrogenase-like protein and chlordecone reductase-like protein respectively. Expression of mRNA species for the five similar cDNA species in 20 liver samples and 10 other different tissue samples was examined by reverse transcriptase-mediated PCR with specific primers followed by diagnostic restriction with endonucleases. All the tissues expressed only one mRNA species corresponding to the newly identified cDNA for DD2: mRNA transcripts corresponding to the other cDNA species were not detected. We suggest that the new cDNA is derived from the principal gene for DD2, which has been named AKR1C2 by a new nomenclature for the AKR superfamily. It is possible that some of the other cDNA species previously reported are rare allelic variants of this gene. PMID:9716498

Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings

NASA Technical Reports Server (NTRS)

Nonhebel, H. M.; Bandurski, R. S.

1984-01-01

Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.
Structure and Function of PA4872 from Pseudomonas aeruginosa, a Novel Class of Oxaloacetate Decarboxylase from the PEP Mutase/Isocitrate Lyase Superfamily

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narayanan, Buvaneswari C.; Niu, Weiling; Han, Ying

2008-06-30

Pseudomonas aeruginosa PA4872 was identified by sequence analysis as a structurally and functionally novel member of the PEP mutase/isocitrate lyase superfamily and therefore targeted for investigation. Substrate screens ruled out overlap with known catalytic functions of superfamily members. The crystal structure of PA4872 in complex with oxalate (a stable analogue of the shared family R-oxyanion carboxylate intermediate/transition state) and Mg{sup 2+} was determined at 1.9 {angstrom} resolution. As with other PEP mutase/isocitrate lyase superfamily members, the protein assembles into a dimer of dimers with each subunit adopting an {alpha}/{beta} barrel fold and two subunits swapping their barrel's C-terminal {alpha}-helices. Mg2+more » and oxalate bind in the same manner as observed with other superfamily members. The active site gating loop, known to play a catalytic role in the PEP mutase and lyase branches of the superfamily, adopts an open conformation. The N{sup {epsilon}} of His235, an invariant residue in the PA4872 sequence family, is oriented toward a C(2) oxygen of oxalate analogous to the C(3) of a pyruvyl moiety. Deuterium exchange into {alpha}-oxocarboxylate-containing compounds was confirmed by {sup 1}H NMR spectroscopy. Having ruled out known activities, the involvement of a pyruvate enolate intermediate suggested a decarboxylase activity of an {alpha}-oxocarboxylate substrate. Enzymatic assays led to the discovery that PA4872 decarboxylates oxaloacetate (k{sub cat}) = 7500 s{sup -1} and K{sub m} = 2.2 mM) and 3-methyloxaloacetate (k{sub cat}) = 250 s{sup -1} and K{sub m} = 0.63 mM). Genome context of the fourteen sequence family members indicates that the enzyme is used by select group of Gram-negative bacteria to maintain cellular concentrations of bicarbonate and pyruvate; however the decarboxylation activity cannot be attributed to a pathway common to the various bacterial species.« less
Formation of Aldehydic Phosphatidylcholines during the Anaerobic Decomposition of a Phosphatidylcholine Bearing the 9-Hydroperoxide of Linoleic Acid

PubMed Central

2016-01-01

Lipid oxidation-derived carbonyl compounds are associated with the development of various physiological disorders. Formation of most of these products has recently been suggested to require further reactions of oxygen with lipid hydroperoxides. However, in rat and human tissues, the formation of 4-hydroxy-2-nonenal is greatly elevated during hypoxic/ischemic conditions. Furthermore, a previous study found an unexpected result that the decomposition of a phosphatidylcholine (PC) bearing the 13-hydroperoxide of linoleic acid under a nitrogen atmosphere afforded 9-oxononanoyl-PC rather than 13-oxo-9,11-tridecadienoyl-PC as the main aldehydic PC. In the present study, products of the anaerobic decomposition of a PC bearing the 9-hydroperoxide of linoleic acid were analysed by electrospray ionization mass spectrometry. 9-Oxononanoyl-PC (ONA-PC) and several well-known bioactive aldehydes including 12-oxo-9-hydroperoxy-(or oxo or hydroxy)-10-dodecenoyl-PCs were detected. Hydrolysis of the oxidized PC products, methylation of the acids obtained thereby, and subsequent gas chromatography-mass spectroscopy with electron impact ionization further confirmed structures of some of the key aldehydic PCs. Novel, hydroxyl radical-dependent mechanisms of formation of ONA-PC and peroxyl-radical dependent mechanisms of formation of the rest of the aldehydes are proposed. The latter mechanisms will mainly be relevant to tissue injury under hypoxic/anoxic conditions, while the former are relevant under both normoxia and hypoxia/anoxia. PMID:27366754
Pericocins A-D, New Bioactive Compounds from Periconia sp.

PubMed

Wu, Yue-Hua; Xiao, Gao-Keng; Chen, Guo-Dong; Wang, Chuan-Xi; Hu, Dan; Lian, Yun-Yang; Lin, Feng; Guo, Liang-Dong; Yao, Xin-Sheng; Gao, Hao

2015-12-01

One new dihydroisocoumarin, pericocin A (1), one new chromone, pericocin B (2), and two new α-pyrone derivatives, pericocins C-D (3-4), together with two known compounds, 3-(2-oxo-2H-pyran-6-yl)propanoic acid (5) and (E)-3-(2-oxo-2H-pyran-6-yl)acrylic acid (6), were isolated from the culture of the endolichenic fungus Periconia sp.. Their structures were elucidated by spectroscopic methods. All these compounds are derived from the polyketone biosynthetic pathway. Compound 1 was obtained as a mixture of enantiomers. The antimicrobial activity of compounds 1-5 was tested against Escherichia coli, Staphylococcus aureus, Aspergillus niger, and Candida albicans. Compounds 1-5 showed moderate antimicrobial activity against A. niger and weak activity against C. albicans.
Endogenous alpha-ketol linolenic acid levels in short day-induced cotyledons are closely related to flower induction in Pharbitis nil.

PubMed

Suzuki, Masayuki; Yamaguchi, Shoko; Iida, Toshii; Hashimoto, Ikue; Teranishi, Hiromi; Mizoguchi, Masaya; Yano, Fumihiko; Todoroki, Yasushi; Watanabe, Naoharu; Yokoyama, Mineyuki

2003-01-01

Alpha-ketol linolenic acid [KODA, 9,10-ketol-octadecadienoic acid, that is 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid] is a signal compound found in Lemna paucicostata after exposure to stress, such as drought, heat or osmotic stress. KODA reacts with catecholamines to generate products that strongly induce flowering, although KODA itself is inactive [Yokoyama et al. (2000) Plant Cell Physiol. 41: 110; Yamaguchi et al. (2001) Plant Cell Physiol. 42: 1201]. We examined the role of KODA in the flower-induction process of Pharbitis nil (violet). KODA was identified for the first time in seedlings of P. nil grown under a flower-inductive condition (16-h dark exposure), by means of LC-SIM and LC-MS/MS. In addition, the changes in endogenous KODA levels (evaluated after esterification of KODA with 9-anthryldiazomethane) during the flower-inductive phase in short day-induced cotyledons were closely related to flower induction. The KODA concentration sharply increased in seedlings during the last 2 h of a 16-h dark period, while the KODA level showed no significant elevation under continuous light. The increase of KODA level occurred in cotyledonal blades, but not in other parts (petiole, hypocotyls and shoot tip). When the 16-h dark period was interrupted with a 10-min light exposure at the 8th h, flower induction was blocked and KODA level also failed to increase. The degree of elevation of KODA concentration in response to 16-h dark exposure was the highest when the cotyledons had just unfolded, and gradually decreased in seedlings grown under continuous light for longer periods, reaching the basal level at the 3rd day after unfolding. Flower-inducing ability also decreased in a similar manner. These results suggest that KODA may be involved in flower induction in P. nil.
Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matte, Allan; Grosse, Stephan; Bergeron, Hélène

The decarboxylation of phenolic acids, including ferulic and p-coumaric acids, to their corresponding vinyl derivatives is of importance in the flavoring and polymer industries. Here, the crystal structure of phenolic acid decarboxylase (PAD) from Bacillus pumilus strain UI-670 is reported. The enzyme is a 161-residue polypeptide that forms dimers both in the crystal and in solution. The structure of PAD as determined by X-ray crystallography revealed a -barrel structure and two -helices, with a cleft formed at one edge of the barrel. The PAD structure resembles those of the lipocalin-fold proteins, which often bind hydrophobic ligands. Superposition of structurally relatedmore » proteins bound to their cognate ligands shows that they and PAD bind their ligands in a conserved location within the -barrel. Analysis of the residue-conservation pattern for PAD-related sequences mapped onto the PAD structure reveals that the conservation mainly includes residues found within the hydrophobic core of the protein, defining a common lipocalin-like fold for this enzyme family. A narrow cleft containing several conserved amino acids was observed as a structural feature and a potential ligand-binding site.« less
Ethylene and 1-MCP regulate major volatile biosynthetic pathways in apple fruit.

PubMed

Yang, Xiaotang; Song, Jun; Du, Lina; Forney, Charles; Campbell-Palmer, Leslie; Fillmore, Sherry; Wismer, Paul; Zhang, Zhaoqi

2016-03-01

The effects of ethylene and 1-methylcyclopropene (1-MCP) on apple fruit volatile biosynthesis and gene expression were investigated. Statistical analysis identified 17 genes that changed significantly in response to ethylene and 1-MCP treatments. Genes encoding branched-chain amino acid aminotransferase (BCAT), aromatic amino acid aminotransferase (ArAT) and amino acid decarboxylases (AADC) were up-regulated during ripening and further enhanced by ethylene treatment. Genes related to fatty acid synthesis and metabolism, including acyl-carrier-proteins (ACPs), malonyl-CoA:ACP transacylase (MCAT), acyl-ACP-desaturase (ACPD), lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), pyruvate decarboxylase (PDC2), β-oxidation, acyl-CoA synthetase (ACS), enoyl-CoA hydratase (ECHD), acyl-CoA dehydrogenase (ACAD), and alcohol acyltransferases (AATs) also increased during ripening and in response to ethylene treatment. Allene oxide synthase (AOS), alcohol dehydrogenase 1 (ADH1), 3-ketoacyl-CoA thiolase and branched-chain amino acid aminotransferase 2 (BCAT2) decreased in ethylene-treated fruit. Treatment with 1-MCP and ethylene generally produced opposite effects on related genes, which provides evidence that regulation of these genes is ethylene dependent. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
75 FR 770 - Acrylic acid-benzyl methacrylate-1-propanesulfonic acid, 2-methyl-2-[(1-oxo-2-propenyl)amino...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-06

....960. Akzo Nobel Surface Chemistry LLC submitted a petition to EPA under the Federal Food, Drug, and... the receipt of a pesticide petition (PP 9E7599) filed by Akzo Nobel Surface Chemistry LLC. The...
Effect of Pyruvate Decarboxylase Knockout on Product Distribution Using Pichia pastoris (Komagataella phaffii) Engineered for Lactic Acid Production.

PubMed

Melo, Nadiele T M; Mulder, Kelly C L; Nicola, André Moraes; Carvalho, Lucas S; Menino, Gisele S; Mulinari, Eduardo; Parachin, Nádia S

2018-02-16

Lactic acid is the monomer unit of the bioplastic poly-lactic acid (PLA). One candidate organism for lactic acid production is Pichia pastoris , a yeast widely used for heterologous protein production. Nevertheless, this yeast has a poor fermentative capability that can be modulated by controlling oxygen levels. In a previous study, lactate dehydrogenase (LDH) activity was introduced into P. pastoris, enabling this yeast to produce lactic acid. The present study aimed to increase the flow of pyruvate towards the production of lactic acid in P. pastoris . To this end, a strain designated GLp was constructed by inserting the bovine lactic acid dehydrogenase gene (LDHb) concomitantly with the interruption of the gene encoding pyruvate decarboxylase (PDC). Aerobic fermentation, followed by micro-aerophilic culture two-phase fermentations, showed that the GLp strain achieved a lactic acid yield of 0.65 g/g. The distribution of fermentation products demonstrated that the acetate titer was reduced by 20% in the GLp strain with a concomitant increase in arabitol production: arabitol increased from 0.025 g/g to 0.174 g/g when compared to the GS115 strain. Taken together, the results show a significant potential for P. pastoris in producing lactic acid. Moreover, for the first time, physiological data regarding co-product formation have indicated the redox balance limitations of this yeast.
Lanostane triterpenes from the mushroom Ganoderma resinaceum and their inhibitory activities against α-glucosidase.

PubMed

Chen, Xian-Qiang; Zhao, Jing; Chen, Ling-Xiao; Wang, Shen-Fei; Wang, Ying; Li, Shao-Ping

2018-05-01

Eighteen previously undescribed lanostane triterpenes and thirty known analogues were obtained from the fruiting bodies of Ganoderma resinaceum. Resinacein C was isolated from a natural source for the first time. The structures of all the above compounds were elucidated by extensive spectroscopic analysis and comparisons of their spectroscopic data with those reported in the literature. Furthermore, in an in vitro assay, Resinacein C, ganoderic acid Y, lucialdehyde C, 7-oxo-ganoderic acid Z 3 , 7-oxo-ganoderic acid Z, and lucidadiol showed strong inhibitory effects against α-glucosidase compared with the positive control drug acarbose. The structure-activity relationships of ganoderma triterpenes on α-glucosidase inhibition showed that the C-24/C-25 double bond is necessary for α-glucosidase inhibitory activity. Moreover, the carboxylic acid group at C-26 and the hydroxy group at C-15 play important roles in enhancing inhibitory effects of these triterpenes. Copyright © 2018. Published by Elsevier Ltd.
Aromatic L-Amino Acid Decarboxylase (AADC) Is Crucial for Brain Development and Motor Functions

PubMed Central

Shih, De-Fen; Hsiao, Chung-Der; Min, Ming-Yuan; Lai, Wen-Sung; Yang, Chianne-Wen; Lee, Wang-Tso; Lee, Shyh-Jye

2013-01-01

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare pediatric neuro-metabolic disease in children. Due to the lack of an animal model, its pathogenetic mechanism is poorly understood. To study the role of AADC in brain development, a zebrafish model of AADC deficiency was generated. We identified an aadc gene homolog, dopa decarboxylase (ddc), in the zebrafish genome. Whole-mount in situ hybridization analysis showed that the ddc gene is expressed in the epiphysis, locus caeruleus, diencephalic catecholaminergic clusters, and raphe nuclei of 36-h post-fertilization (hpf) zebrafish embryos. Inhibition of Ddc by AADC inhibitor NSD-1015 or anti-sense morpholino oligonucleotides (MO) reduced brain volume and body length. We observed increased brain cell apoptosis and loss of dipencephalic catecholaminergic cluster neurons in ddc morphants (ddc MO-injected embryos). Seizure-like activity was also detected in ddc morphants in a dose-dependent manner. ddc morphants had less sensitive touch response and impaired swimming activity that could be rescued by injection of ddc plasmids. In addition, eye movement was also significantly impaired in ddc morphants. Collectively, loss of Ddc appears to result in similar phenotypes as that of ADCC deficiency, thus zebrafish could be a good model for investigating pathogenetic mechanisms of AADC deficiency in children. PMID:23940784
Aromatic L-amino acid decarboxylase (AADC) is crucial for brain development and motor functions.

PubMed

Shih, De-Fen; Hsiao, Chung-Der; Min, Ming-Yuan; Lai, Wen-Sung; Yang, Chianne-Wen; Lee, Wang-Tso; Lee, Shyh-Jye

2013-01-01

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare pediatric neuro-metabolic disease in children. Due to the lack of an animal model, its pathogenetic mechanism is poorly understood. To study the role of AADC in brain development, a zebrafish model of AADC deficiency was generated. We identified an aadc gene homolog, dopa decarboxylase (ddc), in the zebrafish genome. Whole-mount in situ hybridization analysis showed that the ddc gene is expressed in the epiphysis, locus caeruleus, diencephalic catecholaminergic clusters, and raphe nuclei of 36-h post-fertilization (hpf) zebrafish embryos. Inhibition of Ddc by AADC inhibitor NSD-1015 or anti-sense morpholino oligonucleotides (MO) reduced brain volume and body length. We observed increased brain cell apoptosis and loss of dipencephalic catecholaminergic cluster neurons in ddc morphants (ddc MO-injected embryos). Seizure-like activity was also detected in ddc morphants in a dose-dependent manner. ddc morphants had less sensitive touch response and impaired swimming activity that could be rescued by injection of ddc plasmids. In addition, eye movement was also significantly impaired in ddc morphants. Collectively, loss of Ddc appears to result in similar phenotypes as that of ADCC deficiency, thus zebrafish could be a good model for investigating pathogenetic mechanisms of AADC deficiency in children.
Understanding the roles of glutamine synthetase, glutaminase, and glutamate decarboxylase autoantibodies in imbalanced excitatory/inhibitory neurotransmission as etiological mechanisms of autism.

PubMed

Hamed, Najat O; Al-Ayadhi, Laila; Osman, Mohamed A; Elkhawad, Abdalla O; Qasem, Hanan; Al-Marshoud, Majida; Merghani, Nada M; El-Ansary, Afaf

2018-05-01

Autism is a heterogeneous neurological disorder that is characterized by impairments in communication and social interactions, repetitive behaviors, and sensory abnormalities. The etiology of autism remains unclear. Animal, genetic, and post-mortem studies suggest that an imbalance exists in the neuronal excitation and inhibition system in autism. The aim of this study was to determine whether alterations of the measured parameters in children with autism are significantly associated with the risk of a sensory dysfunction. The glutamine synthetase (GS), kidney-type glutaminase (GLS1), and glutamic acid decarboxylase autoantibody levels were analyzed in 38 autistic children and 33 age- and sex-matched controls using enzyme-linked immunosorbent assays. The obtained data demonstrated significant alterations in glutamate and glutamine cycle enzymes, as represented by GS and GLS1, respectively. While the glutamic acid decarboxylase autoantibodies levels were remarkably increased, no significant difference was observed compared to the healthy control participants. The obtained data indicate that GS and GLS1 are promising indicators of a neuronal excitation and inhibition system imbalance and that combined measured parameters are good predictive biomarkers of autism. © 2018 The Authors. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.
Elevated Levels of Urinary Markers of Oxidative DNA and RNA Damage in Type 2 Diabetes with Complications.

PubMed

Liu, Xinle; Gan, Wei; Zou, Yuangao; Yang, Bin; Su, Zhenzhen; Deng, Jin; Wang, Lanlan; Cai, Jianping

2016-01-01

The mechanisms underlying progression of type 2 diabetes are complex and varied. Recent studies indicated that oxidative stress provided a new sight. To further assess the relationship between nucleic acid oxidation and complications in patients with type 2 diabetes and explore its possible molecular mechanisms, we studied 1316 subjects, including 633 type 2 diabetes patients and 683 age- and sex-matched healthy controls. Urinary levels of DNA oxidation marker 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and RNA oxidation marker 8-oxo-7,8-dihydroguanosine (8-oxoGuo) were measured by ultraperformance liquid chromatography and mass spectrometry (UPLC-MS/MS). Serum glucose, HbA1c, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides (TG) were also determined. The results showed significantly elevated levels of both the urinary 8-oxodGuo and 8-oxoGuo in diabetes patients with/without complications compared with age-matched healthy control subjects (p = 0.02 and p < 0.001, resp.). Patients with complications, especially macrovascular complications, exhibited higher levels of 8-oxoGuo than those without complications, while there was no difference in the concentrations of serum glucose and lipids. The finding indicates the role for oxidative damage to DNA and RNA, as a molecular mechanism contributing to the progression of type 2 diabetes. Elevated levels of 8-oxoGuo may be a risk factor for type 2 diabetes complications, especially in diabetic macrovascular complications.
Isolation and identification of oligomers from partial degradation of lime fruit cutin.

PubMed

Tian, Shiying; Fang, Xiuhua; Wang, Weimin; Yu, Bingwu; Cheng, Xiaofang; Qiu, Feng; Mort, Andrew J; Stark, Ruth E

2008-11-12

Complementary degradative treatments with low-temperature hydrofluoric acid and methanolic potassium hydroxide have been used to investigate the protective biopolymer cutin from Citrus aurantifolia (lime) fruits, augmenting prior enzymatic and chemical strategies to yield a more comprehensive view of its molecular architecture. Analysis of the resulting soluble oligomeric fragments with one- and two-dimensional NMR and MS methods identified a new dimer and three trimeric esters of primary alcohols based on 10,16-dihydroxyhexadecanoic acid and 10-oxo-16-hydroxyhexadecanoic acid units. Whereas only 10-oxo-16-hydroxyhexadecanoic acid units were found in the oligomers from hydrofluoric acid treatments, the dimer and trimer products isolated to date using diverse degradative methods included six of the seven possible stoichiometric ratios of monomer units. A novel glucoside-linked hydroxyfatty acid tetramer was also identified provisionally, suggesting that the cutin biopolymer can be bound covalently to the plant cell wall. Although the current findings suggest that the predominant molecular architecture of this protective polymer in lime fruits involves esters of primary and secondary alcohols based on long-chain hydroxyfatty acids, the possibility of additional cross-linking to enhance structural integrity is underscored by these and related findings of nonstandard cutin molecular architectures.
Microenvironment of Breast Tissue: Lithocholic Acid and Other Intestinal Steroids.

DTIC Science & Technology

1997-09-01

6. chenodeoxycholic acid -7-sulfate 7. ursodeoxycholic acid 8. glycodeoxycholic acid 9. 3ß-hydroxy-5-cholenoic acid sulfate 10. cholicacid 11. 3a... acids 7 Ursodeoxycholic acid 29.1 10 Cholic acid 32.5 11 3ß,7a-Dihydroxy-chol-5-enoicacidJ 33.3 12 7a-Hydroxy-3-oxo-chol-4-enoic acidc 34.1 16...AD GRANT NUMBER DAMD17-94-J-4311 TITLE: Microenvironment of: Breast Tissue: Lithocholic Acid and Other Intestinal Steroids PRINCIPAL
SYNTHETIC LUBRICANTS

DTIC Science & Technology

azelaic , and sebacic acids are the most readily available dibasic acids suitable for ester lubricant production, while the petroleum derived Oxo alcohols...of synthetic lubricants for use at low and high temperatures. The diesters of straight-chain dibasic acids lead the field of esters mutable as...dibasic acid esters in all the characteristics studied so far, and this type of ester therefore represents a promising source of synthetic oil. Mono
40 CFR 721.10020 - Benzoic acid, 5-amino-2-chloro-, 1,1-dimethyl-2-oxo-2-(2-propenyloxy) ethyl ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzoic acid, 5-amino-2-chloro-, 1,1... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10020 Benzoic acid, 5-amino-2-chloro... subject to reporting. (1) The chemical substance identified as benzoic acid, 5-amino-2-chloro-, 1,1...
40 CFR 721.10020 - Benzoic acid, 5-amino-2-chloro-, 1,1-dimethyl-2-oxo-2-(2-propenyloxy) ethyl ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzoic acid, 5-amino-2-chloro-, 1,1... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10020 Benzoic acid, 5-amino-2-chloro... subject to reporting. (1) The chemical substance identified as benzoic acid, 5-amino-2-chloro-, 1,1...
Design and synthesis of highly potent benzodiazepine gamma-secretase inhibitors: preparation of (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4- hydroxy-N-((3S)-1-methyl-2-oxo-5- phenyl-2,3-dihydro-1H-benzo[e][1,4]-diazepin-3-yl)butyramide by use of an asymmetric Ireland-Claisen rearrangement.

PubMed

Churcher, Ian; Williams, Susie; Kerrad, Sonia; Harrison, Timothy; Castro, José L; Shearman, Mark S; Lewis, Huw D; Clarke, Earl E; Wrigley, Jonathan D J; Beher, Dirk; Tang, Yui S; Liu, Wensheng

2003-06-05

Novel benzodiazepine-containing gamma-secretase inhibitors for potential use in Alzheimer's disease have been designed that incorporate a substituted hydrocinnamide C-3 side chain. A syn combination of alpha-alkyl or aryl and beta-hydroxy or hydroxymethyl substituents was shown to give highly potent compounds. In particular, (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4-hydroxy-N-((3S)-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)butyramide (34) demonstrated excellent in vitro potency (IC(50) = 0.06 nM). 34 could also be selectively methylated to give [(3)H]-28, which is of use in radioligand binding assays.

Production of gamma-aminobutyric acid from glucose by introduction of synthetic scaffolds between isocitrate dehydrogenase, glutamate synthase and glutamate decarboxylase in recombinant Escherichia coli.

PubMed

Pham, Van Dung; Lee, Seung Hwan; Park, Si Jae; Hong, Soon Ho

2015-08-10

Escherichia coli were engineered for the direct production of gamma-aminobutyric acid from glucose by introduction of synthetic protein scaffold. In this study, three enzymes consisting GABA pathway (isocitrate dehydrogenase, glutamate synthase and glutamate decarboxylase) were connected via synthetic protein scaffold. By introduction of scaffold, 0.92g/L of GABA was produced from 10g/L of glucose while no GABA was produced in wild type E. coli. The optimum pH and temperature for GABA production were 4.5 and 30°C, respectively. When competing metabolic network was inactivated by knockout mutation, maximum GABA concentration of 1.3g/L was obtained from 10g/L glucose. The recombinant E. coli strain which produces GABA directly from glucose was successfully constructed by introduction of protein scaffold. Copyright © 2015 Elsevier B.V. All rights reserved.
Neurologic disorders associated with anti-glutamic acid decarboxylase antibodies: A comparison of anti-GAD antibody titers and time-dependent changes between neurologic disease and type I diabetes mellitus.

PubMed

Nakajima, Hideto; Nakamura, Yoshitsugu; Inaba, Yuiko; Tsutsumi, Chiharu; Unoda, Kiichi; Hosokawa, Takafumi; Kimura, Fumiharu; Hanafusa, Toshiaki; Date, Masamichi; Kitaoka, Haruko

2018-04-15

To determine clinical features of neurologic disorders associated with anti-glutamic acid decarboxylase antibodies (anti-GAD-Ab), we examined titers and time-dependent changes of anti-GAD-Ab. Six patients, stiff person syndrome (2), cerebellar ataxia (1), limbic encephalitis (1), epilepsy (1), brainstem encephalitis (1), were compared with 87 type I diabetes mellitus (T1DM) patients without neurologic disorders. Anti-GAD-Ab titers and index were higher in neurologic disorders than in T1DM, suggesting intrathecal antibody synthesis. Anti-GAD-Ab titers in T1DM decreased over time, whereas they remained high in neurologic disorders. Immunotherapy improved neurological disorders and anti-GAD-Ab titers and index provide clinically meaningful information about their diagnostic accuracy. Copyright © 2018 Elsevier B.V. All rights reserved.
Detailed dimethylacetal and fatty acid composition of rumen content from lambs fed lucerne or concentrate supplemented with soybean oil.

PubMed

Alves, Susana P; Santos-Silva, José; Cabrita, Ana R J; Fonseca, António J M; Bessa, Rui J B

2013-01-01

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18:2n-6 and 18:3n-3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n-3.
Precipitation pathways for ferrihydrite formation in acidic solutions

DOE PAGES

Zhu, Mengqiang; Khalid, Syed; Frandsen, Cathrine; ...

2015-10-03

In this study, iron oxides and oxyhydroxides form via Fe 3+ hydrolysis and polymerization in many aqueous environments, but the pathway from Fe 3+ monomers to oligomers and then to solid phase nuclei is unknown. In this work, using combined X-ray, UV–vis, and Mössbauer spectroscopic approaches, we were able to identify and quantify the long-time sought ferric speciation over time during ferric oxyhydroxide formation in partially-neutralized ferric nitrate solutions ([Fe 3+] = 0.2 M, 1.8 < pH < 3). Results demonstrate that Fe exists mainly as Fe(H 2O) 6 3+, μ-oxo aquo dimers and ferrihydrite, and that with time, themore » μ-oxo dimer decreases while the other two species increase in their concentrations. No larger Fe oligomers were detected. Given that the structure of the μ-oxo dimer is incompatible with those of all Fe oxides and oxyhydroxides, our results suggest that reconfiguration of the μ-oxo dimer structure occurs prior to further condensation leading up to the nucleation of ferrihydrite. The structural reconfiguration is likely the rate-limiting step involved in the nucleation process.« less
Parallel synthesis: a new approach for developing analytical internal standards. Application to the analysis of patulin by gas chromatography-mass spectrometry.

PubMed

Llovera, Montserrat; Balcells, Mercè; Torres, Mercè; Canela, Ramon

2005-08-24

The polymer-assisted reaction of 4-(hydroxymethyl)furan-2(5H)-one (4HM2F) with 21 carboxylic acids using polystyrene-carbodiimide (PS-carbodiimide) yielded an ester library. Four of the esters, (5-oxo-2,5-dihydrofuran-3-yl)methyl acetate (IS-1), (5-oxo-2,5-dihydrofuran-3-yl)methyl butyrate (IS-2), (5-oxo-2,5-dihydrofuran-3-yl)methyl 2-methylpropanoate (IS-3), and (5-oxo-2,5-dihydrofuran-3-yl)methyl chloroacetate (IS-4), were tested as internal standards for the quantification of patulin in apple juice by gas chromatography-mass spectrometry in the selected ion monitoring mode (GC-MS-SIM). The developed method combines an AOAC official extractive step and a GC-MS-SIM analysis. Using a chromatographic column containing trifluoropropylmethylpolysiloxane as the stationary phase and IS-1 as the internal standard, it was possible to perform an accurate and precise quantification of underivatizated patulin in apple juice at concentrations down to 6 microg/L. A detection limit of 1 microg/L was established.
Alkylation of an active-site cysteinyl residue during substrate-dependent inactivation of Escherichia coli S-adenosylmethionine decarboxylase.

PubMed

Diaz, E; Anton, D L

1991-04-23

S-Adenosylmethionine decarboxylase from Escherichia coli is a member of a small class of enzymes that uses a pyruvoyl prosthetic group. The pyruvoyl group is proposed to form a Schiff base with the substrate and then act as an electron sink facilitating decarboxylation. We have previously shown that once every 6000-7000 turnovers the enzyme undergoes an inactivation that results in a transaminated pyruvoyl group and the formation of an acrolein-like species from the methionine moiety. The acrolein then covalently alkylates the enzyme [Anton, D. L., & Kutny, R. (1987) Biochemistry 26, 6444]. After reduction of the alkylated enzyme with NaBH4, a tryptic peptide with the sequence Ala-Asp-Ile-Glu-Val-Ser-Thr-[S-(3-hydroxypropyl)Cys]-Gly-Val-Ile-Ser-Pro - Leu-Lys was isolated. This corresponds to acrolein alkylation of a cysteine residue in the second tryptic peptide from the NH2 terminal of the alpha-subunit [Anton, D. L., & Kutny, R. (1987) J. Biol. Chem. 262, 2817-2822]. The modified residue derived is from Cys-140 of the proenzyme [Tabor, C. W., & Tabor, H. (1987) J. Biol. Chem. 262, 16037-16040] and lies in the only sequence conserved between rat liver and E. coli S-adenosylmethionine decarboxylase [Pajunen et al. (1988) J. Biol. Chem. 263, 17040-17049]. We suggest that the alkylated Cys residue could have a role in the catalytic mechanism.
Paraneoplastic epilepsy.

PubMed

Serafini, Anna; Lukas, Rimas V; VanHaerents, Stephen; Warnke, Peter; Tao, James X; Rose, Sandra; Wu, Shasha

2016-08-01

Epilepsy can be a manifestation of paraneoplastic syndromes which are the consequence of an immune reaction to neuronal elements driven by an underlying malignancy affecting other organs and tissues. The antibodies commonly found in paraneoplastic encephalitis can be divided into two main groups depending on the target antigen: 1) antibodies against neuronal cell surface antigens, such as against neurotransmitter (N-methyl-d-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), gamma-aminobutyric acid (GABA)) receptors, ion channels (voltage-gated potassium channel (VGKC)), and channel-complex proteins (leucine rich, glioma inactivated-1 glycoprotein (LGI1) and contactin-associated protein-2 (CASPR2)) and 2) antibodies against intracellular neuronal antigens (Hu/antineuronal nuclear antibody-1 (ANNA-1), Ma2/Ta, glutamate decarboxylase 65 (GAD65), less frequently to CV2/collapsin response mediator protein 5 (CRMP5)). In this review, we provide a comprehensive survey of the current literature on paraneoplastic epilepsy indexed by the associated onconeuronal antibodies. While a range of seizure types can be seen with paraneoplastic syndromes, temporal lobe epilepsy is the most common because of the association with limbic encephalitis. Early treatment of the paraneoplastic syndrome with immune modulation/suppression may prevent the more serious potential consequences of paraneoplastic epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.
Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

ERIC Educational Resources Information Center

Kolb, Kenneth E.; Kolb, Doris

1983-01-01

Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)
Synthesis of carrier-free tritium-labeled queen bee pheromone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webster, F.X.; Prestwich, G.D.

A short synthesis of (4,5-/sup 3/H/sub 2/) (E)-9-oxo-2-decenoic acid (ODA), a high-specific-activity tritium-containing isotopomer of the queen bee pheromone, is described. Catalytic tritiation of the ketal of ethyl 9-oxo-4-decenoate introduces tritium into two positions, one of which is completely unactivated. Subsequent transformation by selenation, oxidation, and hydrolysis affords the labeled 9-ODA at >60 Ci/mmol. The material is suitable for biochemical studies of binding and catabolism in ovarian, antennal, and other target tissues.
The gas–liquid chromatography of carboxylic acid esters of the urinary 11-deoxy-17-oxo steroids

PubMed Central

Sadler, Patricia A.; Kellie, A. E.

1967-01-01

1. The gas–liquid-chromatographic separations of the acetate, propionate, n-butyrate, isobutyrate and n-valerate esters of androsterone, aetiocholanolone and dehydroepiandrosterone were studied on a 1% neopentyl glycol sebacate column. The n-butyrate, isobutyrate and n-valerate esters were well resolved. 2. The three steroids derived from hydrolysed urinary 17-oxo steroid conjugate extracts were analysed by gas–liquid chromatography after conversion into their n-butyrate esters. The results were compared with independent determinations involving chromatography on alumina. PMID:4227802
The gas-liquid chromatography of carboxylic acid esters of the urinary 11-deoxy-17-oxo steroids. Determination as n-butyrates.

PubMed

Sadler, P A; Kellie, A E

1967-06-01

1. The gas-liquid-chromatographic separations of the acetate, propionate, n-butyrate, isobutyrate and n-valerate esters of androsterone, aetiocholanolone and dehydroepiandrosterone were studied on a 1% neopentyl glycol sebacate column. The n-butyrate, isobutyrate and n-valerate esters were well resolved. 2. The three steroids derived from hydrolysed urinary 17-oxo steroid conjugate extracts were analysed by gas-liquid chromatography after conversion into their n-butyrate esters. The results were compared with independent determinations involving chromatography on alumina.
Pauson-Khand adducts of N-Boc-propargylamine: a new approach to 4,5-disubstituted cyclopentenones.

PubMed

Aiguabella, Nuria; Pesquer, Albert; Verdaguer, Xavier; Riera, Antoni

2013-06-07

A new approach to the synthesis of 4,5-disubstituted cyclopentenones is described. The strategy is based on the Pauson-Khand (PK) reaction of norbornadiene and N-Boc-propargylamine as an alkyne with a masked leaving group, which can be eliminated at will. This approach to the synthesis of 4,5-disubstituted cyclopentenones overcomes the problem of using the alkylation to introduce the α side chain. As an example, prostane 13-epi-12-oxo-phytodienoic acid (13-epi-12-oxo-PDA) methyl ester was synthesized.
The Role of Bi3+ in Promoting and Stabilizing Iron Oxo Clusters in Strong Acid.

PubMed

Sadeghi, Omid; Amiri, Mehran; Reinheimer, Eric W; Nyman, May

2018-05-22

Metal oxo clusters and metal oxides assemble and precipitate from water in processes that depend on pH, temperature, and concentration. Other parameters that influence the structure, composition, and nuclearity of "molecular" and bulk metal oxides are poorly understood, and have thus not been exploited. Herein, we show that Bi 3+ drives the formation of aqueous Fe 3+ clusters, usurping the role of pH. We isolated and structurally characterized a Bi/Fe cluster, Fe 3 BiO 2 (CCl 3 COO) 8 (THF)(H 2 O) 2 , and demonstrated its conversion into an iron Keggin ion capped by six Bi 3+ irons (Bi 6 Fe 13 ). The reaction pathway was documented by X-ray scattering and mass spectrometry. Opposing the expected trend, increased cluster nuclearity required a pH decrease instead of a pH increase. We attribute this anomalous behavior of Bi/Fe(aq) solutions to Bi 3+ , which drives hydrolysis and condensation. Likewise, Bi 3+ stabilizes metal oxo clusters and metal oxides in strongly acidic conditions, which is important in applications such as water oxidation for energy storage. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Syntheses and biological activities of 13-substituted avermectin aglycons.

PubMed

Mrozik, H; Linn, B O; Eskola, P; Lusi, A; Matzuk, A; Preiser, F A; Ostlind, D A; Schaeffer, J M; Fisher, M H

1989-02-01

The reactions of sulfonate esters of the allylic/homoallylic 13-alcohol of 5-O-(tert-butyldimethylsilyl)-22,23-dihydroavermectin B1a aglycon (1a) were investigated. Nucleophilic substitution gave 13 beta-chloro and 13 beta-iodo derivatives, while solvolytic reaction conditions yielded 13 alpha-methoxy, 13 alpha-fluoro, and 13 alpha-chloro products. A mixture of 13 alpha- and 13 beta-fluorides was obtained upon reaction with DAST. The 13 beta-iodide gave, upon elimination with lutidine, the 8(9),10(11),12(13),14(15)-tetraene. The 13 beta-alcohol and the rearranged 15-ol 13(14)-ene and 15-amino 13(14)-ene derivatives were obtained by substitution via the allylic carbonium ion. MEM ethers 11 and 12 of the two epimeric 13-ols were prepared by alkylation with MEM chloride. In contrast, methylation of 1a with MeI and Ag2O in CH2Cl2 occurred exclusively at the tertiary 7-hydroxy group and not at the secondary 13 alpha-ol. Oxidation of the allylic alcohol 1a proceeded under Swern conditions but not with MnO2 to the 13-oxo aglycon, which was reduced by NaBH4 exclusively to the natural 13 alpha-ol, while reductive amination with NaCNBH3-NH4OAc gave the 13 alpha-amine. The methoxime derivative was obtained in the form of the two geometric isomers. Anthelmintic activities against the sheep nematode Trichostrongylus colubriformis, miticidal activities against the two-spotted spider mite (Tetranychus urticae), and insecticidal activities against the southern armyworm (Spodoptera eridania) as well as the binding constants to a free living nematode (Caenorhabditis elegans) derived receptor assay were obtained and compared to avermectin B1a, 22,23-dihydroavermectin B1a, and the 13-deoxy-22,23-dihydroavermectin B1 aglycon related to the milbemycins. None of the newly prepared derivatives exceeded the potency of the three reference compounds. Lipophilic 13-substituents such as halogen, alkoxy, and methoxime retained high biological activities in all assays, while the more polar substituents hydroxy and amino had weaker activities. Rearranged 15-substituted 13(14)-ene derivatives were completely inactive. The 13-oxo and the 12,13-dehydro analogues were only weakly active in vivo despite having good binding affinity to the receptor, possibly due to instability or poor absorption.
Study of pyruvate decarboxylase and thiamine kinase from brewer's yeast by SERS

NASA Astrophysics Data System (ADS)

Maskevich, Sergei A.; Chernikevich, Ivan P.; Gachko, Gennedy A.; Kivach, Leonid N.; Strekal, Nataliya D.

1993-06-01

The Surface Enhanced Raman Scattering (SERS) spectra of holopyruvate decarboxylase (PDC) and thiamine kinase (ThK) adsorbed on silver electrode were obtained. In contrast to the Raman, the SERS spectrum of PDC contained no modes of tryptophan residues, it indicates a removal of this moiety from the surface. In the SERS spectrum of ThK the bands belonging to ligands bound to the protein were observed. A correlation between the SERS signal intensity and the enzymatic activity of the ThK separate fraction and found. The influence of amino acids on SERS spectra of thiamine (Th) was studied to determine the possible composition on microsurrounding of coenzyme.
Micro liquid chromatography-mass spectrometry with direct liquid introduction used for separation and quantitation of all-trans- and 13-cis-retinoic acids and their 4-oxo metabolites in human plasma.

PubMed

Ranalder, U B; Lausecker, B B; Huselton, C

1993-07-23

The separation and quantitation of the pentafluorobenzyl derivatives of all-trans- and 13-cis-retinoic acids and their 4-oxo metabolites in human plasma on micro high-performance liquid chromatographic columns (0.32 mm I.D.) is described. The column outlet was directly coupled to the source of a quadrupole mass spectrometer via a simple SFC-frit interface. Negative ion chemical ionization conditions were obtained by coaxial introduction of ammonia as a reagent gas. A signal-to-noise ratio well above 3 was obtained for 1 pg of each analyte injected. The limit of quantitation calculated from spiked biological plasma extracts was 0.3 ng/ml.
Histidine-decarboxylase knockout mice show deficient nonreinforced episodic object memory, improved negatively reinforced water-maze performance, and increased neo- and ventro-striatal dopamine turnover.

PubMed

Dere, Ekrem; De Souza-Silva, Maria A; Topic, Bianca; Spieler, Richard E; Haas, Helmut L; Huston, Joseph P

2003-01-01

The brain's histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain's histamine system exerts inhibitory effects on the brain's reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced water-maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved water-maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independent mechanisms and further indicate that these opposed effects are related to the task-inherent reinforcement contingencies.
Cloning and expression analysis of the ornithine decarboxylase gene (PbrODC) of the pathogenic fungus Paracoccidioides brasiliensis.

PubMed

Niño-Vega, Gustavo A; Sorais, Françoise; Calcagno, Ana-María; Ruiz-Herrera, José; Martínez-Espinoza, Alfredo D; San-Blas, Gioconda

2004-02-01

We describe the isolation and sequencing of PbrODC, the gene encoding ornithine decarboxylase (ODC) in Paracoccidioides brasiliensis. The gene contains a single open reading frame made of 1413 bp with a single intron (72 bp), and encodes a 447 amino acid polypeptide with a predicted molecular weight of 50.0 kDa, an isoelectric point of 4.9 and a high similarity to other fungal ornithine decarboxylases. Functionality of the gene was demonstrated by transformation into a Saccharomyces cerevisiae odc null mutant. A phylogenetic tree generated with several fungal ODCs provided additional evidence to favour a taxonomic position for P. brasiliensis as an ascomycetous fungus, belonging to the order Onygenales. Expression of the PbrODC gene was determined by Northern analyses during growth of the mycelial and yeast forms, and through the temperature-regulated dimorphic transition between these two extreme phases. Expression of PbrODC remained constant at all stages of the fungal growth, and did not correlate with a previously observed increase in the activity of ornithine decarboxylase at the onset of the budding process in both yeast growth and mycelium-to-yeast transition. Accordingly, post-transcriptional regulation for the product of PbrODC is suggested. Copyright 2004 John Wiley & Sons, Ltd.
Contribution of polyamines metabolism and GABA shunt to chilling tolerance induced by nitric oxide in cold-stored banana fruit.

PubMed

Wang, Yansheng; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

2016-04-15

Effect of exogenous nitric oxide (NO) on polyamines (PAs) catabolism, γ-aminobutyric acid (GABA) shunt, proline accumulation and chilling injury of banana fruit under cold storage was investigated. Banana fruit treated with NO sustained lower chilling injury index than the control. Notably elevated nitric oxide synthetase activity and endogenous NO level were observed in NO-treated banana fruit. PAs contents in treated fruit were significantly higher than control fruit, due to the elevated activities of arginine decarboxylase and ornithine decarboxylase. NO treatment increased the activities of diamine oxidase, polyamine oxidase and glutamate decarboxylase, while reduced GABA transaminase activity to lower levels compared with control fruit, which resulted the accumulation of GABA. Besides, NO treatment upregulated proline content and significantly enhanced the ornithine aminotransferase activity. These results indicated that the chilling tolerance induced by NO treatment might be ascribed to the enhanced catabolism of PAs, GABA and proline. Copyright © 2015 Elsevier Ltd. All rights reserved.
Characterisation of the broad substrate specificity 2-keto acid decarboxylase Aro10p of Saccharomyces kudriavzevii and its implication in aroma development.

PubMed

Stribny, Jiri; Romagnoli, Gabriele; Pérez-Torrado, Roberto; Daran, Jean-Marc; Querol, Amparo

2016-03-12

The yeast amino acid catabolism plays an important role in flavour generation since higher alcohols and acetate esters, amino acid catabolism end products, are key components of overall flavour and aroma in fermented products. Comparative studies have shown that other Saccharomyces species, such as S. kudriavzevii, differ during the production of aroma-active higher alcohols and their esters compared to S. cerevisiae. In this study, we performed a comparative analysis of the enzymes involved in the amino acid catabolism of S. kudriavzevii with their potential to improve the flavour production capacity of S. cerevisiae. In silico screening, based on the severity of amino acid substitutions evaluated by Grantham matrix, revealed four candidates, of which S. kudriavzevii Aro10p (SkAro10p) had the highest score. The analysis of higher alcohols and esters produced by S. cerevisiae then revealed enhanced formation of isobutanol, isoamyl alcohol and their esters when endogenous ARO10 was replaced with ARO10 from S. kudriavzevii. Also, significant differences in the aroma profile were found in fermentations of synthetic wine must. Substrate specificities of SkAro10p were compared with those of S. cerevisiae Aro10p (ScAro10p) by their expression in a 2-keto acid decarboxylase-null S. cerevisiae strain. Unlike the cell extracts with expressed ScAro10p which showed greater activity for phenylpyruvate, which suggests this phenylalanine-derivative to be the preferred substrate, the decarboxylation activities measured in the cell extracts with SkAro10p ranged with all the tested substrates at the same level. The activities of SkAro10p towards substrates (except phenylpyruvate) were higher than of those for ScAro10p. The results indicate that the amino acid variations observed between the orthologues decarboxylases encoded by SkARO10 and ScARO10 could be the reason for the distinct enzyme properties, which possibly lead to the enhanced production of several flavour compounds. The knowledge on the important enzyme involved in higher alcohols biosynthesis by S. kudriavzevii could be of scientific as well as of applied interest.

Characterization of the tumor-promoting activity of m-chloroperoxybenzoic acid in SENCAR mouse skin and its inhibition by gallotannin, oligomeric proanthocyanidin, and their monomeric units

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Fatima K. Johnson; Amy W. Davis; Steven W. Newell; Richard W. Hemingway; Vittorio Bottari; Jean-Pierre Perchellet

1996-01-01

m-Chloroperoxybenzoic acid (CPBA). which induces ornithine decarboxylase activity as much as 12-0-tetradecanoylphorbol-13-acetate (TPA ), was tested for its ability to induce DNA synthesis, hydroperoxide (HPx) production, and tumor promotion in mouse epidermis in vivo. After an early inhibition, CPBA stimulates...
Gamma-Aminobutyric Acid Production Using Immobilized Glutamate Decarboxylase Followed by Downstream Processing with Cation Exchange Chromatography

PubMed Central

Lee, Seungwoon; Ahn, Jungoh; Kim, Yeon-Gu; Jung, Joon-Ki; Lee, Hongweon; Lee, Eun Gyo

2013-01-01

We have developed a gamma-aminobutyric acid (GABA) production technique using his-tag mediated immobilization of Escherichia coli-derived glutamate decarboxylase (GAD), an enzyme that catalyzes the conversion of glutamate to GABA. The GAD was obtained at 1.43 g/L from GAD-overexpressed E. coli fermentation and consisted of 59.7% monomer, 29.2% dimer and 2.3% tetramer with a 97.6% soluble form of the total GAD. The harvested GAD was immobilized to metal affinity gel with an immobilization yield of 92%. Based on an investigation of specific enzyme activity and reaction characteristics, glutamic acid (GA) was chosen over monosodium glutamate (MSG) as a substrate for immobilized GAD, resulting in conversion of 2.17 M GABA in a 1 L reactor within 100 min. The immobilized enzymes retained 58.1% of their initial activities after ten consecutive uses. By using cation exchange chromatography followed by enzymatic conversion, GABA was separated from the residual substrate and leached GAD. As a consequence, the glutamic acid was mostly removed with no detectable GAD, while 91.2% of GABA was yielded in the purification step. PMID:23322022
Dysfunction in GABA signalling mediates autism-like stereotypies and Rett syndrome phenotypes.

PubMed

Chao, Hsiao-Tuan; Chen, Hongmei; Samaco, Rodney C; Xue, Mingshan; Chahrour, Maria; Yoo, Jong; Neul, Jeffrey L; Gong, Shiaoching; Lu, Hui-Chen; Heintz, Nathaniel; Ekker, Marc; Rubenstein, John L R; Noebels, Jeffrey L; Rosenmund, Christian; Zoghbi, Huda Y

2010-11-11

Mutations in the X-linked MECP2 gene, which encodes the transcriptional regulator methyl-CpG-binding protein 2 (MeCP2), cause Rett syndrome and several neurodevelopmental disorders including cognitive disorders, autism, juvenile-onset schizophrenia and encephalopathy with early lethality. Rett syndrome is characterized by apparently normal early development followed by regression, motor abnormalities, seizures and features of autism, especially stereotyped behaviours. The mechanisms mediating these features are poorly understood. Here we show that mice lacking Mecp2 from GABA (γ-aminobutyric acid)-releasing neurons recapitulate numerous Rett syndrome and autistic features, including repetitive behaviours. Loss of MeCP2 from a subset of forebrain GABAergic neurons also recapitulates many features of Rett syndrome. MeCP2-deficient GABAergic neurons show reduced inhibitory quantal size, consistent with a presynaptic reduction in glutamic acid decarboxylase 1 (Gad1) and glutamic acid decarboxylase 2 (Gad2) levels, and GABA immunoreactivity. These data demonstrate that MeCP2 is critical for normal function of GABA-releasing neurons and that subtle dysfunction of GABAergic neurons contributes to numerous neuropsychiatric phenotypes.
Development and validation of an LC-MS/MS method to quantify lysergic acid diethylamide (LSD), iso-LSD, 2-oxo-3-hydroxy-LSD, and nor-LSD and identify novel metabolites in plasma samples in a controlled clinical trial.

PubMed

Dolder, Patrick C; Liechti, Matthias E; Rentsch, Katharina M

2018-02-01

Lysergic acid diethylamide (LSD) is a widely used recreational drug. The aim of this study was to develop and validate a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the quantification of LSD, iso-LSD, 2-oxo-3-hydroxy LSD (O-H-LSD), and nor-LSD in plasma samples from 24 healthy subjects after controlled administration of 100 μg LSD in a clinical trial. In addition, metabolites that have been recently described in in vitro studies, including lysergic acid monoethylamide (LAE), lysergic acid ethyl-2-hydroxyethylamide (LEO), 2-oxo-LSD, trioxylated-LSD, and 13/14-hydroxy-LSD, should be identified. Separation of LSD and its metabolites was achieved on a reversed phase chromatography column after turbulent-flow online extraction. For the identification and quantification, a triple-stage quadrupole LC-MS/MS instrument was used. The validation data showed slight matrix effects for LSD, iso-LSD, O-H-LSD, or nor-LSD. Mean intraday and interday accuracy and precision were 105%/4.81% and 105%/4.35% for LSD, 98.7%/5.75% and 99.4%/7.21% for iso-LSD, 106%/4.54% and 99.4%/7.21% for O-H-LSD, and 107%/5.82% and 102%/5.88% for nor-LSD, respectively. The limit of quantification was 0.05 ng/mL for LSD, iso-LSD, and nor-LSD and 0.1 ng/mL for O-H-LSD. The limit of detection was 0.01 ng/mL for all compounds. The method described herein was accurate, precise, and the calibration range within the range of expected plasma concentrations. LSD was quantified in the plasma samples of the 24 subjects of the clinical trial, whereas iso-LSD, O-H-LSD, nor-LSD, LAE, LEO, 13/14-hydroxy-LSD, and 2-oxo-LSD could only sporadically be detected but were too low for quantification. © 2017 Wiley Periodicals, Inc.
LC-mS analysis of human urine specimens for 2-oxo-3-hydroxy LSD: method validation for potential interferants and stability study of 2-oxo-3-hydroxy LSD under various storage conditions.

PubMed

Klette, Kevin L; Horn, Carl K; Stout, Peter R; Anderson, Cynthia J

2002-01-01

2-Oxo-3-hydroxy lysergic acid diethylamide (O-H-LSD), a major LSD metabolite, has previously been demonstrated to be a superior marker for identifying LSD use compared with the parent drug, LSD. Specifically, O-H-LSD analyzed using liquid chromatography-mass spectrometry has been reported to be present in urine at concentrations 16 to 43 times greater than LSD. To further support forensic application of this procedure, the specificity of the assay was assessed using compounds that have structural and chemical properties similar to O-H-LSD, common over-the-counter products, prescription drugs and some of their metabolites, and other drugs of abuse. Of the wide range of compounds studied, none were found to interfere with the detection of O-H-LSD or the internal standard 2-oxo-3-hydroxy lysergic acid methyl propylamide. The stability of O-H-LSD was investigated from 0 to 9 days at various temperatures, pH conditions, and exposures to fluorescent light. Additionally, the effect of long-term frozen storage and pH was investigated from 0 to 60 days. There was no significant loss of O-H-LSD under both refrigerated and frozen conditions within the normal human physiological pH range of urine (4.6-8.4). However, significant loss of O-H-LSD was observed in samples prepared at pH 4.6-8.4 and stored at room temperature or higher (24-50 degrees C).
Crystal Structure and Substrate Specificity of Drosophila 3,4-Dihydroxyphenylalanine Decarboxylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Q.; Ding, H; Robinson, H

2010-01-01

3,4-Dihydroxyphenylalanine decarboxylase (DDC), also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses. In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82more » and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine. The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins.« less
Amphetamine regulation of acetylcholine and gamma-aminobutyric acid in nucleus accumbens.

PubMed

Lindefors, N; Hurd, Y L; O'Connor, W T; Brené, S; Persson, H; Ungerstedt, U

1992-01-01

In situ hybridization histochemistry and in vivo microdialysis were combined to study the effect of amphetamine on the expression of choline acetyltransferase and glutamate decarboxylase67 mRNA and in vivo release of acetylcholine and GABA in rat medial nucleus accumbens. Differential effects on acetylcholine and GABA neurons by a single challenge injection of amphetamine (1.5 mg/kg, s.c.) were apparent in saline-pretreated and amphetamine-pretreated (same dose, twice daily for the previous seven days) rats. Extracellular acetylcholine levels were increased up to 50% over a prolonged period following both single and repeated amphetamine. In contrast, extracellular concentrations of GABA were gradually decreased to half the control values, but only in rats receiving repeated amphetamine. Although the increase of acetylcholine release was not associated with any change in choline acetyltransferase mRNA levels, the number of neurons expressing high levels of glutamate decarboxylase67 mRNA was decreased (28%) following repeated injections. Thus we suggest that amphetamine decreases extracellular GABA levels by a slow mechanism, associated with the decreased expression of glutamate decarboxylase67 mRNA in a subpopulation of densely labeled neurons in the medial nucleus accumbens. The delayed response by GABA to amphetamine may reflect supersensitivity in the activity of postsynaptic gamma-aminobutyric acid-containing neurons in nucleus accumbens as a consequence of the repeated amphetamine treatment.
Structural Characterization of the Molecular Events during a Slow Substrate-Product Transition in Orotidine 5'-Monophosphate Decarboxylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujihashi, Masahiro; Wei, Lianhu; Kotra, Lakshmi P

2009-04-06

Crystal structures of substrate-product complexes of Methanobacterium thermoautotrophicum orotidine 5'-monophosphate decarboxylase, obtained at various steps in its catalysis of the unusual transformation of 6-cyano-uridine 5'-monophosphate (UMP) into barbituric acid ribosyl monophosphate, show that the cyano substituent of the substrate, when bound to the active site, is first bent significantly from the plane of the pyrimidine ring and then replaced by an oxygen atom. Although the K72A and D70A/K72A mutants are either catalytically impaired or even completely inactive, they still display bending of the C6 substituent. Interestingly, high-resolution structures of the D70A and D75N mutants revealed a covalent bond between C6more » of UMP and the Lys72 side chain after the -CN moiety's release. The same covalent bond was observed when the native enzyme was incubated with 6-azido-UMP and 6-iodo-UMP; in contrast, the K72A mutant transformed 6-iodo-UMP to barbituric acid ribosyl 5'-monophosphate. These results demonstrate that, given a suitable environment, native orotidine 5'-monophosphate decarboxylase and several of its mutants are not restricted to the physiologically relevant decarboxylation; they are able to catalyze even nucleophilic substitution reactions but consistently maintain distortion on the C6 substituent as an important feature of catalysis.« less
Structural characterization of the molecular events during a slow substrate-product transition in orotidine 5'-monophosphate decarboxylase.

PubMed

Fujihashi, Masahiro; Wei, Lianhu; Kotra, Lakshmi P; Pai, Emil F

2009-04-17

Crystal structures of substrate-product complexes of Methanobacterium thermoautotrophicum orotidine 5'-monophosphate decarboxylase, obtained at various steps in its catalysis of the unusual transformation of 6-cyano-uridine 5'-monophosphate (UMP) into barbituric acid ribosyl monophosphate, show that the cyano substituent of the substrate, when bound to the active site, is first bent significantly from the plane of the pyrimidine ring and then replaced by an oxygen atom. Although the K72A and D70A/K72A mutants are either catalytically impaired or even completely inactive, they still display bending of the C6 substituent. Interestingly, high-resolution structures of the D70A and D75N mutants revealed a covalent bond between C6 of UMP and the Lys72 side chain after the -CN moiety's release. The same covalent bond was observed when the native enzyme was incubated with 6-azido-UMP and 6-iodo-UMP; in contrast, the K72A mutant transformed 6-iodo-UMP to barbituric acid ribosyl 5'-monophosphate. These results demonstrate that, given a suitable environment, native orotidine 5'-monophosphate decarboxylase and several of its mutants are not restricted to the physiologically relevant decarboxylation; they are able to catalyze even nucleophilic substitution reactions but consistently maintain distortion on the C6 substituent as an important feature of catalysis.
Molecular characteristic and physiological role of DOPA-decarboxylase.

PubMed

Guenter, Joanna; Lenartowski, Robert

2016-12-31

The enzyme DOPA decarboxylase (aromatic-L-amino-acid decarboxylase, DDC) plays an important role in the dopaminergic system and participates in the uptake and decarboxylation of amine precursors in the peripheral tissues. Apart from catecholamines, DDC catalyses the biosynthesis of serotonin and trace amines. It has been shown that the DDC amino acid sequence is highly evolutionarily conserved across many species. The activity of holoenzyme is regulated by stimulation/blockade of membrane receptors, phosphorylation of serine residues, and DDC interaction with regulatory proteins. A single gene codes for DDC both in neuronal and non-neuronal tissue, but synthesized isoforms of mRNA differ in the 5' UTR and in the presence of alternative exons. Tissue-specific expression of the DDC gene is controlled by two spatially distinct promoters - neuronal and non-neuronal. Several consensus sequences recognized by the HNF and POU family proteins have been mapped in the neuronal DDC promoter. Since DDC is located close to the imprinted gene cluster, its expression can be subjected to tightly controlled epigenetic regulation. Perturbations in DDC expression result in a range of neurodegenerative and psychiatric disorders and correlate with neoplasia. Apart from the above issues, the role of DDC in prostate cancer, bipolar affective disorder, Parkinson's disease and DDC deficiency is discussed in our review. Moreover, novel and prospective clinical treatments based on gene therapy and stem cells for the diseases mentioned above are described.
Cadmium-induced accumulation of putrescine in oat and bean leaves

NASA Technical Reports Server (NTRS)

Weinstein, L. H.; Kaur-Sawhney, R.; Rajam, M. V.; Wettlaufer, S. H.; Galston, A. W.

1986-01-01

The effects of Cd2+ on putrescine (Put), spermidine (Spd), and spermine (Spm) titers were studied in oat and bean leaves. Treatment with Cd2+ for up to 16 hours in the light or dark resulted in a large increase in Put titer, but had little or no effect on Spd or Spm. The activity of arginine decarboxylase (ADC) followed the pattern of Put accumulation, and experiments with alpha-difluoromethylarginine established that ADC was the enzyme responsible for Put increase. Concentrations of Cd2+ as low as 10 micromolar increased Put titer in oat segments. In bean leaves, there was a Cd(2+)-induced accumulation of Put in the free and soluble conjugated fractions, but not in the insoluble fraction. This suggests a rapid exchange between Put that exists in the free form and Put found in acid soluble conjugate forms. It is concluded that Cd2+ can act like certain other stresses (K+ and Mg2+ deficiency, excess NH4+, low pH, salinity, osmotic stress, wilting) to induce substantial increases in Put in plant cells.
Biochemical analysis of active site mutations of human polymerase η.

PubMed

Suarez, Samuel C; Beardslee, Renee A; Toffton, Shannon M; McCulloch, Scott D

2013-01-01

DNA polymerase η (pol η) plays a critical role in suppressing mutations caused by the bypass of cis-syn cyclobutane pyrimidine dimers (CPD) that escape repair. There is evidence this is also the case for the oxidative lesion 7,8-dihydro-8-oxo-guanine (8-oxoG). Both of these lesions cause moderate to severe blockage of synthesis when encountered by replicative polymerases, while pol η displays little no to pausing during translesion synthesis. However, since lesion bypass does not remove damaged DNA from the genome and can possibly be accompanied by errors in synthesis during bypass, the process is often called 'damage tolerance' to delineate it from classical DNA repair pathways. The fidelity of lesion bypass is therefore of importance when determining how pol η suppresses mutations after DNA damage. As pol η has been implicated in numerous in vivo pathways other than lesion bypass, we wanted to better understand the molecular mechanisms involved in the relatively low-fidelity synthesis displayed by pol η. To that end, we have created a set of mutant pol η proteins each containing a single amino acid substitution in the active site and closely surrounding regions. We determined overall DNA synthesis ability as well as the efficiency and fidelity of bypass of thymine-thymine CPD (T-T CPD) and 8-oxoG containing DNA templates. Our results show that several amino acids are critical for normal polymerase function, with changes in overall activity and fidelity being observed. Of the mutants that retain polymerase activity, we demonstrate that amino acids Q38, Y52, and R61 play key roles in determining polymerase fidelity, with substation of alanine causing both increases and decreases in fidelity. Remarkably, the Q38A mutant displays increased fidelity during synthesis opposite 8-oxoG but decreased fidelity during synthesis opposite a T-T CPD. Copyright © 2013 Elsevier B.V. All rights reserved.
Selective Catalytic Reduction of NO by NH 3 with WO 3-TiO 2 Catalysts: Influence of Catalyst Synthesis Method

DOE PAGES

He, Yuanyuan; Ford, Michael E.; Zhu, Minghui; ...

2016-02-02

A series of supported WO 3/TiO 2 catalysts was prepared by a new synthesis procedure involving co-precipitation of an aqueous TiO(OH) 2 and (NH 4) 10W 12O 41*5H 2O slurry under controlled pH conditions. The morphological properties, molecular structures, surface acidity and surface chemistry of the supported WO 3/TiO 2 catalysts were determined with BET, in situ Raman, in situ IR and temperature-programmed surface reaction (TPSR) spectroscopy, respectively. Isotopic 18O- 16O exchange demonstrated that tungsten oxide was exclusively present as surface WO x species on the TiO 2 support with mono-oxo W=O coordination. In contrast to previous studies employing impregnationmore » synthesis that found only surface one mono-oxo O=WO 4 site on TiO 2, the co-precipitation procedure resulted in the formation of two distinct surface WO x species: mono-oxo O=WO 4 (~1010-1017 cm -1) on low defect density patches of TiO 2 and a second mono-oxo O=WO 4 (~983-986 cm -1) on high defect density patches of TiO 2. The concentration of the second WO x surface species increases as a function of solution pH. Both surface WOx sites, however, exhibited the same NO/NH 3 SCR reactivity. The co-precipitated WO 3-TiO 2 catalysts synthesized in alkaline solutions exhibited enhanced performance for the NO/NH 3 SCR reaction that is ascribed to the greater number of surface defects on the resulting TiO2 support. For the co-precipitated catalyst prepared at pH10, surface NH 4 + species on Br nsted acid sites were found to be more reactive than surface NH 3* species on Lewis acid sites for SCR of NO with NH 3.« less
Muscarinic cholinergic and alpha/sub 1/ adrenergic receptors in murine atria: phosphatidylinositol breakdown and receptor interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scherer, R.W.

Upon stimulation of muscarinic cholinergic receptors, there is a decrease in the force of contraction rate of firing in heart, while stimulation of ..cap alpha.. adrenergic receptors causes an increase in the force of contraction with no change in the heart rate. Yet both receptors stimulate the breakdown of phosphatidylinositol (PI). Therefore, the breakdown of PI was examined to determine how the process differed between the two receptor systems. Murine atria, prelabelled with (/sup 3/H)inositol, were stimulated with the muscarinic cholinergic agonists, carbamylcholine (CARB), and oxotremorine (OXO); and with the ..cap alpha.. adrenergic agonists, norepinephrine (NE) and phenylephrine (PE); eithermore » singly or in combination. Breakdown of PI was assessed by measurement of individual inositol phosphates by anion exchange chromatography. Binding of CARB to atrial muscarinic receptors was measured by competition with (/sup 3/H)quinuclidinyl benzilate.« less
Malonyl-CoA Decarboxylase (MCD) as a Potential Therapeutic Target for Breast Cancer

DTIC Science & Technology

2010-05-01

Kreb cycle and electron transport activity. Clinical and biochemical studies of MCD deficiency, a rare inborn error of metabolism, provide another... mitochondria and is the rate limiting enzymatic step of mitochondrial fatty acid oxidation (Figure 1) (McGarry and Brown, 1997). Indeed, the 10-fold...1 activity and fatty acid oxidation, thereby preventing a futile cycle of fatty acid synthesis and oxidation. As FAS could consume malonyl-CoA, it was
High Phenotypic Variability among Representative Strains of Common Salmonella enterica Serovars with Possible Implications for Food Safety.

PubMed

Abdullah, Wan Zawiah Wan; Mackey, Bernard M; Karatzas, Kimon Andreas G

2018-01-01

Salmonella is an important foodborne pathogen, whose ability to resist stress and survive can vary among strains. This variability is normally not taken into account when predictions are made about survival in foods with negative consequences. Therefore, we examined the contribution of variable phenotypic properties to survival under stress in 10 Salmonella serovars. One strain (Typhimurium 10) was intentionally RpoS-negative; however, another strain (Heidelberg) showed an rpoS mutation, rendering it inactive. We assessed an array of characteristics (motility, biofilm formation, bile resistance, acid resistance, and colony morphology) that show major variability among strains associated with a 10- to 19-fold difference between the highest and the lowest strain for most characteristics. The RpoS status of isolates did not affect variability in the characteristics, with the exception of resistance to NaCl, acetic acid, lactic acid, and the combination of acetic acid and salt, where the variability between the highest and the lowest strain was reduced to 3.1-fold, 1.7-fold, 2-fold, and 1.7-fold, respectively, showing that variability was significant among RpoS-positive strains. Furthermore, we also found a good correlation between acid resistance and lysine decarboxylase activity, showing its importance for acid resistance, and demonstrated a possible role of RpoS in the lysine decarboxylase activity in Salmonella.
Detailed Dimethylacetal and Fatty Acid Composition of Rumen Content from Lambs Fed Lucerne or Concentrate Supplemented with Soybean Oil

PubMed Central

Alves, Susana P.; Santos-Silva, José; Cabrita, Ana R. J.; Fonseca, António J. M.; Bessa, Rui J. B.

2013-01-01

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18∶1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18∶2n−6 and 18∶3n−3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18∶0 might be produced during biohydrogenation of the 18∶3n−3. PMID:23484024
Spectral and in vitro antimicrobial properties of 2-oxo-4-phenyl-6-styryl-1,2,3,4-tetrahydro-pyrimidine-5-carboxylic acid transition metal complexes

NASA Astrophysics Data System (ADS)

Dhankar, Raksha P.; Rahatgaonkar, Anjali M.; Chorghade, Mukund S.; Tiwari, Ashutosh

2-oxo-4-phenyl-6-styryl-1,2,3,4-tetrahydro-pyrimidine-5-carboxylic acid (ADP) was complexed with acetates of Mn(II), Ni(II), Cu(II) and Zn(II). The structures of the ligand and its metal complexes were characterized by microanalysis, IR, NMR, UV-vis spectroscopy, magnetic susceptibility and TGA-DTA analyses. Octahedral and square planar geometries were suggested for the complexes in which the central metal ion coordinated with sbnd O donors of ligand and acetate ions. Each ligand binds the metal using carboxylate oxygens. The ligand and complexes were evaluated for their antimicrobial activities against different species of pathogenic bacteria and fungi. The present novel pyrimidine containing complexes could constitute a new group of antibacterial and antifungal agents.
Contribution of the 7β-hydroxysteroid dehydrogenase from Ruminococcus gnavus N53 to ursodeoxycholic acid formation in the human colon.

PubMed

Lee, Ja-Young; Arai, Hisashi; Nakamura, Yusuke; Fukiya, Satoru; Wada, Masaru; Yokota, Atsushi

2013-11-01

Bile acid composition in the colon is determined by bile acid flow in the intestines, the population of bile acid-converting bacteria, and the properties of the responsible bacterial enzymes. Ursodeoxycholic acid (UDCA) is regarded as a chemopreventive beneficial bile acid due to its low hydrophobicity. However, it is a minor constituent of human bile acids. Here, we characterized an UDCA-producing bacterium, N53, isolated from human feces. 16S rDNA sequence analysis identified this isolate as Ruminococcus gnavus, a novel UDCA-producer. The forward reaction that produces UDCA from 7-oxo-lithocholic acid was observed to have a growth-dependent conversion rate of 90-100% after culture in GAM broth containing 1 mM 7-oxo-lithocholic acid, while the reverse reaction was undetectable. The gene encoding 7β-hydroxysteroid dehydrogenase (7β-HSDH), which facilitates the UDCA-producing reaction, was cloned and overexpressed in Escherichia coli. Characterization of the purified 7β-HSDH revealed that the kcat/Km value was about 55-fold higher for the forward reaction than for the reverse reaction, indicating that the enzyme favors the UDCA-producing reaction. As R. gnavus is a common, core bacterium of the human gut microbiota, these results suggest that this bacterium plays a pivotal role in UDCA formation in the colon.
Contribution of the 7β-hydroxysteroid dehydrogenase from Ruminococcus gnavus N53 to ursodeoxycholic acid formation in the human colon[S

PubMed Central

Lee, Ja-Young; Arai, Hisashi; Nakamura, Yusuke; Fukiya, Satoru; Wada, Masaru; Yokota, Atsushi

2013-01-01

Bile acid composition in the colon is determined by bile acid flow in the intestines, the population of bile acid-converting bacteria, and the properties of the responsible bacterial enzymes. Ursodeoxycholic acid (UDCA) is regarded as a chemopreventive beneficial bile acid due to its low hydrophobicity. However, it is a minor constituent of human bile acids. Here, we characterized an UDCA-producing bacterium, N53, isolated from human feces. 16S rDNA sequence analysis identified this isolate as Ruminococcus gnavus, a novel UDCA-producer. The forward reaction that produces UDCA from 7-oxo-lithocholic acid was observed to have a growth-dependent conversion rate of 90–100% after culture in GAM broth containing 1 mM 7-oxo-lithocholic acid, while the reverse reaction was undetectable. The gene encoding 7β-hydroxysteroid dehydrogenase (7β-HSDH), which facilitates the UDCA-producing reaction, was cloned and overexpressed in Escherichia coli. Characterization of the purified 7β-HSDH revealed that the kcat/Km value was about 55-fold higher for the forward reaction than for the reverse reaction, indicating that the enzyme favors the UDCA-producing reaction. As R. gnavus is a common, core bacterium of the human gut microbiota, these results suggest that this bacterium plays a pivotal role in UDCA formation in the colon. PMID:23729502

Acetone production by methylobacteria.

PubMed

Thomson, A W; O'Neill, J G; Wilkinson, J F

1976-09-01

An accumulation of acetone was observed during the metabolism of ethane and products of ethane oxidation by washed suspensions of Methylosinus trichosporium OB3B. This strain possessed an acetoacetate decarboxylase and 3-hydroxybutyrate dehydrogenase, and a decline in poly-beta-hydroxybutyric acid occurred under the same conditions as acetone formation. A pathway of acetone production from poly-beta-hydroxybutyric acid via 3-hydroxybutyrate and acetoacetate was suggested.
Redox interplay of oxo-thio-tungsten centers with sulfur-donor co-ligands.

PubMed

Thomas, Simon; Eagle, Aston A; Sproules, Stephen A; Hill, Jason P; White, Jonathan M; Tiekink, Edward R T; George, Graham N; Young, Charles G

2003-09-22

The oxo-thio-W(VI) complexes TpWOS(S(2)PR(2)-S) and TpWOS(pyS-S) (Tp = hydrotris(3,5-dimethylpyrazol-1-yl)borate, R = OEt, Ph; pyS = pyridine-2-thiolate) have been prepared and characterized by microanalytical, spectroscopic, and structural techniques. Crystals of the 1,2-dichloroethane hemisolvate of TpWOS(S(2)PPh(2)-S) belong to the triclinic space group Ponemacr; with a = 10.732(6) A, b = 16.91(1) A, c = 10.021(4) A, alpha = 104.40(4) degrees, beta = 107.52(3) degrees, gamma = 96.09(5) degrees, V = 1647(1) A(3) for Z = 2. The complex exhibits a distorted octahedral structure featuring a facial tridentate Tp ligand and mutually cis terminal oxo (W-O(1) = 1.712(7) A), terminal thio (W-S(1) = 2.162(3) A), and monodentate dithiophosphinate ligands. X-ray absorption and extended X-ray absorption fine structure results support a related oxo-thio formulation for TpWOS(pyS-S). The complexes are reduced to the corresponding oxo-thio-W(V) anions, [TpWOS(S(2)PR(2)-S)](-) and [TpWOS(pyS-S)](-), which exhibit highly anisotropic EPR spectra. They are oxidized to form the EPR-active (dithio)oxo-W(V) cations, [TpWO(S(3)PR(2)-S,S')](+) and [TpWO(pyS(2)-N,S)](+) (pyS(2) = pyridine-2-dithio). Green [TpWO(pyS(2)-N,S)]BF(4), formed in the reaction of TpWOS(pyS) and NOBF(4), has been isolated and spectroscopically and structurally characterized. Crystals of [TpWO(pyS(2)-N,S)]BF(4) belong to the monoclinic space group Cc with a = 16.007(5) A, b = 14.091(4) A, c = 13.608(4) A, beta = 124.525(4) degrees, V = 2528.8(13) A(3) for Z = 4. The cation exhibits a distorted octahedral structure featuring facial tridentate Tp, terminal oxo (W-O(1) = 1.632(12) A), and bidentate pyridine-2-dithio-N,S (W-S(1) = 2.317(7) A, S(1)-S(2) = 2.037(9) A) ligands. The structures and redox behavior of the complexes are compared and contrasted with those of the related molybdenum complexes, TpMo(VI)OS(S(2)PR(2)-S) and TpMo(IV)O(pyS(2)-N,S) (Hill, J. P.; Laughlin, L. J.; Gable, R. W.; Young, C. G. Inorg. Chem. 1996, 35, 3447).
Aerobic biodegradation of 2,2'-dithiodibenzoic acid produced from dibenzothiophene metabolites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, R.F.; Cheng, S.M.; Fedorak, P.M.

Dibenzothiophene is a sulfur heterocycle found in crude oils and coal. The biodegradation of dibenzothiophene through the Kodama pathway by Pseudomonas sp. strain BT1d leads to the formation of three disulfides: 2-oxo-2-(2-thiophenyl)ethanoic acid disulfide, 2-oxo-2-(2-thiophenyl)ethanoic acid-2-benzoic acid disulfide, and 2,2'-dithiodibenzoic acid. When provided as the carbon and sulfur source in liquid medium, 2,2'-dithiodibenzoic acid was degraded by soil enrichment cultures. Two bacterial isolates, designated strains RM1 and RM6, degraded 2,2'-dithiodibenzoic acid when combined in the medium. Isolate RM6 was found to have an absolute requirement for vitamin B{sub 12}, and it degraded 2,2'-dithiodibenzoic acid in pure culture when the mediummore » was supplemented with this vitamin. Isolate RM6 also degraded 2,2'-dithiodibenzoic acid in medium containing sterilized supernatants from cultures of isolate RM1 grown on glucose or benzoate. Isolate RM6 was identified as a member of the genus Variovorax using the Biolog system and 16S rRNA gene analysis. Although the mechanism of disulfide metabolism could not be determined, benzoic acid was detected as a transient metabolite of 2,2'-dithiodibenzoic acid biodegradation by Variovorax sp. strain RM6. In pure culture, this isolate mineralized 2,2'-dithiodibenzoic acid, releasing 59% of the carbon as carbon dioxide and 88% of the sulfur as sulfate.« less
The high sensitivity of the rabbit to the teratogenic effects of 13-cis-retinoic acid (isotretinoin) is a consequence of prolonged exposure of the embryo to 13-cis-retinoic acid and 13-cis-4-oxo-retinoic acid, and not of isomerization to all-trans-retinoic acid.

PubMed

Tzimas, G; Bürgin, H; Collins, M D; Hummler, H; Nau, H

1994-01-01

Previous studies suggested that the rabbit is much more susceptible to the teratogenic action of 13-cis-retinoic acid (13-cis-RA) than the mouse or the rat, while the teratogenicity of all-trans-RA was comparable in these species. In the present study we investigated if pharmacokinetics can explain these species- and structure-related differences. The embryotoxic and teratogenic potential of all-trans-retinoic acid (all-trans-RA) and 13-cis-RA were evaluated in the Swiss hare rabbit after oral administration of daily doses of the two drugs throughout organogenesis, from gestation day (GD) 6 to 18 (plug day = GD 0). All-trans-RA was given at dose levels of 0.7, 2 or 6 mg/kg body weight per day and 13-cis-RA at 3, 7.5 or 10 mg/kg per day. The doses needed to elicit a minimum teratogenic response were found to be 6 mg/kg per day for all-trans-RA and 10 mg/kg per day for 13-cis-RA. Using these doses, transplacental pharmacokinetics of all-trans- and 13-cis-RA were performed. Pregnant rabbits were treated once daily from GD 7 to 12 and plasma and embryo samples were collected for HPLC analysis at various time intervals after the final dose. The main plasma metabolites of all-trans- and 13-cis-RA were all-trans-beta-glucuronide (all-trans-RAG) and 13-cis-4-oxo-RA, respectively. The elimination of 13-cis-RA and its metabolites from maternal plasma were much slower than of all-trans-RA resulting in accumulation of the 13-cis-isomers in plasma. Marked differences in the placental transfer of the two drugs and their metabolites were observed. All-trans-RA and all-trans-4-oxo-RA were efficiently transferred to the rabbit embryo, reaching concentrations similar to the plasma levels. On the contrary, the 13-cis-isomers reached the embryo to a lesser extent. Despite its limited placental transfer, a considerable embryonic exposure to 13-cis-RA and 13-cis-4-oxo-RA was noticed after treatment with isotretinoin, as indicated by their area-under-the-concentration-time-curve (AUC) values in the embryo, which were in the same range as the corresponding AUC value of all-trans-RA after treatment with the all-trans-isomer.(ABSTRACT TRUNCATED AT 400 WORDS)
Atorvastatin protects GABAergic and dopaminergic neurons in the nigrostriatal system in an experimental rat model of transient focal cerebral ischemia.

PubMed

Sabogal, Angélica María; Arango, César Augusto; Cardona, Gloria Patricia; Céspedes, Ángel Enrique

2014-01-01

Cerebral ischemia is the third leading cause of death and the primary cause of permanent disability worldwide. Atorvastatin is a promising drug with neuroprotective effects that may be useful for the treatment of stroke. However, the effects of atorvastatin on specific neuronal populations within the nigrostriatal system following cerebral ischemia are unknown. To evaluate the effects of atorvastatin on dopaminergic and GABAergic neuronal populations in exofocal brain regions in a model of transient occlusion of the middle cerebral artery. Twenty-eight male eight-week-old Wistar rats were used in this study. Both sham and ischemic rats were treated with atorvastatin (10 mg/kg) or carboxymethylcellulose (placebo) by gavage at 6, 24, 48 and 72 hours post-reperfusion. We analyzed the immunoreactivity of glutamic acid decarboxylase and tyrosine hydroxylase in the globus pallidus, caudate putamen and substantia nigra. We observed neurological damage and cell loss in the caudate putamen following ischemia. We also found an increase in tyrosine hydroxylase immunoreactivity in the medial globus pallidus and substantia nigra reticulata, as well as a decrease in glutamic acid decarboxylase immunoreactivity in the lateral globus pallidus in ischemic animals treated with a placebo. However, atorvastatin treatment was able to reverse these effects, significantly decreasing tyrosine hydroxylase levels in the medial globus pallidus and substantia nigra reticulata and significantly increasing glutamic acid decarboxylase levels in the lateral globus pallidus. Our data suggest that post-ischemia treatment with atorvastatin can have neuro-protective effects in exofocal regions far from the ischemic core by modulating the GABAergic and dopaminergic neuronal populations in the nigrostriatal system, which could be useful for preventing neurological disorders.
Use of self-collected capillary blood samples for islet autoantibody screening in relatives: a feasibility and acceptability study.

PubMed

Liu, Y; Rafkin, L E; Matheson, D; Henderson, C; Boulware, D; Besser, R E J; Ferrara, C; Yu, L; Steck, A K; Bingley, P J

2017-07-01

To evaluate the feasibility of using self-collected capillary blood samples for islet autoantibody testing to identify risk in relatives of people with Type 1 diabetes. Participants were recruited via the observational TrialNet Pathway to Prevention study, which screens and monitors relatives of people with Type 1 diabetes for islet autoantibodies. Relatives were sent kits for capillary blood collection, with written instructions, an online instructional video link and a questionnaire. Sera from capillary blood samples were tested for autoantibodies to glutamic acid decarboxylase, islet antigen-2, insulin and zinc transporter 8. 'Successful' sample collection was defined as obtaining sufficient volume and quality to provide definitive autoantibody results, including confirmation of positive results by repeat assay. In 240 relatives who returned samples, the median (range) age was 15.5 (1-49) years and 51% were male. Of these samples, 98% were sufficient for glutamic acid decarboxylase, islet antigen-2 and zinc transporter 8 autoantibody testing and 84% for insulin autoantibody testing and complete autoantibody screen. The upper 90% confidence bound for unsuccessful collection was 4.4% for glutamic acid decarboxylase, islet antigen-2 and/or zinc transporter 8 autoantibody assays, and 19.3% for insulin autoantibodies. Despite 43% of 220 questionnaire respondents finding capillary blood collection uncomfortable or painful, 82% preferred home self-collection of capillary blood samples compared with outpatient venepuncture (90% of those aged <8 years, 83% of those aged 9-18 years and 73% of those aged >18 years). The perceived difficulty of collecting capillary blood samples did not affect success rate. Self-collected capillary blood sampling offers a feasible alternative to venous sampling, with the potential to facilitate autoantibody screening for Type 1 diabetes risk. © 2017 Diabetes UK.
Loss of Autonoetic Awareness of Recent Autobiographical Episodes and Accelerated Long-Term Forgetting in a Patient with Previously Unrecognized Glutamic Acid Decarboxylase Antibody Related Limbic Encephalitis.

PubMed

Witt, Juri-Alexander; Vogt, Viola Lara; Widman, Guido; Langen, Karl-Josef; Elger, Christian Erich; Helmstaedter, Christoph

2015-01-01

We describe a 35-year-old male patient presenting with depressed mood and emotional instability, who complained about severe anterograde and retrograde memory deficits characterized by accelerated long-term forgetting and loss of autonoetic awareness regarding autobiographical memories of the last 3 years. Months before he had experienced two breakdowns of unknown etiology giving rise to the differential diagnosis of epileptic seizures after various practitioners and clinics had suggested different etiologies such as a psychosomatic condition, burnout, depression, or dissociative amnesia. Neuropsychological assessment indicated selectively impaired figural memory performance. Extended diagnostics confirmed accelerated forgetting of previously learned and retrievable verbal material. Structural imaging showed bilateral swelling and signal alterations of temporomesial structures (left >right). Video-EEG monitoring revealed a left temporal epileptic focus and subclincal seizure, but no overt seizures. Antibody tests in serum and liquor were positive for glutamic acid decarboxylase antibodies. These findings led to the diagnosis of glutamic acid decarboxylase antibody related limbic encephalitis. Monthly steroid pulses over 6 months led to recovery of subjective memory and to intermediate improvement but subsequent worsening of objective memory performance. During the course of treatment, the patient reported de novo paroxysmal non-responsive states. Thus, antiepileptic treatment was started and the patient finally became seizure free. At the last visit, vocational reintegration was successfully in progress. In conclusion, amygdala swelling, retrograde biographic memory impairment, accelerated long-term forgetting, and emotional instability may serve as indicators of limbic encephalitis, even in the absence of overt epileptic seizures. The monitoring of such patients calls for a standardized and concerted multilevel diagnostic approach with repeated assessments.
A new class of fatty acid allene oxide formed by the DOX-P450 fusion proteins of human and plant pathogenic fungi, C. immitis and Z. tritici[S

PubMed Central

Oliw, Ernst H.; Aragó, Marc; Chen, Yang; Jernerén, Fredrik

2016-01-01

Linoleate dioxygenase-cytochrome P450 (DOX-CYP) fusion enzymes are common in pathogenic fungi. The DOX domains form hydroperoxy metabolites of 18:2n-6, which can be transformed by the CYP domains to 1,2- or 1,4-diols, epoxy alcohols, or to allene oxides. We have characterized two novel allene oxide synthases (AOSs), namely, recombinant 8R-DOX-AOS of Coccidioides immitis (causing valley fever) and 8S-DOX-AOS of Zymoseptoria tritici (causing septoria tritici blotch of wheat). The 8R-DOX-AOS oxidized 18:2n-6 sequentially to 8R-hydroperoxy-9Z,12Z-octadecadienoic acid (8R-HPODE) and to an allene oxide, 8R(9)-epoxy-9,12Z-octadecadienoic acid, as judged from the accumulation of the α-ketol, 8S-hydroxy-9-oxo-12Z-octadecenoic acid. The 8S-DOX-AOS of Z. tritici transformed 18:2n-6 sequentially to 8S-HPODE and to an α-ketol, 8R-hydroxy-9-oxo-12Z-octadecenoic acid, likely formed by hydrolysis of 8S(9)-epoxy-9,12Z-octadecadienoic acid. The 8S-DOX-AOS oxidized [8R-2H]18:2n-6 to 8S-HPODE with retention of the 2H-label, suggesting suprafacial hydrogen abstraction and oxygenation in contrast to 8R-DOX-AOS. Both enzymes oxidized 18:1n-9 and 18:3n-3 to α-ketols, but the catalysis of the 8R- and 8S-AOS domains differed. 8R-DOX-AOS transformed 9R-HPODE to epoxy alcohols, but 8S-DOX-AOS converted 9S-HPODE to an α-ketol (9-hydroxy-10-oxo-12Z-octadecenoic acid) and epoxy alcohols in a ratio of ∼1:2. Whereas all fatty acid allene oxides described so far have a conjugated diene impinging on the epoxide, the allene oxides formed by 8-DOX-AOS are unconjugated. PMID:27282156
In vivo measurements of changes in pH triggered by oxalic acid in leaf tissue of transgenic oilseed rape.

PubMed

Zou, Qiu-Ju; Liu, Sheng-Yi; Dong, Xu-Yan; Bi, Yan-Hua; Cao, Yuan-Cheng; Xu, Qiao; Zhao, Yuan-Di; Chen, Hong

2007-01-01

Oxalic acid (OA), a non-host-specific toxin secreted by Sclerotinia sclerotiorum during pathogenesis, has been demonstrated to be a major phytotoxic and pathogenic factor. Oxalate oxidase (OXO) is an enzyme associated with the detoxification of OA, and hence the introduction of an OXO gene into oilseed rape (Brassica napus L.) to break down OA may be an alternative way of increasing the resistance of the plant to Sclerotinia sclerotiorum. In order to investigate the activation of OXO in transgenic oilseed rape, a convenient and accessible method was used to monitor changes in pH in response to stress induced by OA. The pH sensor, a platinum microcylinder electrode modified using polyaniline film, exhibited a linear response within the pH range from 3 to 7, with a Nernst response slope of 70 mV/pH at room temperature. The linear correlation coefficient was 0.9979. Changes induced by OA in the pH values of leaf tissue of different oilseed rape species from Brassica napus L. were monitored in real time in vivo using this electrode. The results clearly showed that the transgenic oilseed rape was more resistant to OA than non-transgenic oilseed rape. Copyright (c) 2007 John Wiley & Sons, Ltd.
Ferromagnetic coupling in the three-dimensional malonato-bridged gadoliniumIII complex [Gd2(mal)3(H2O)6] (H2mal = malonic acid).

PubMed

Hernández-Molina, María; Ruiz-Pérez, Catalina; López, Trinidad; Lloret, Francesc; Julve, Miguel

2003-09-08

The novel gadolinium(III) complex of formula [Gd(2)(mal)(3)(H(2)O)(6)] (1) (H(2)mal = 1,3-propanedioic acid) has been prepared and characterized by X-ray diffraction analysis. Crystal data for 1: monoclinic, space group I2/a, a = 11.1064(10) A, b = 12.2524(10) A, c =13.6098(2) A, beta = 92.925(10) degrees, U = 1849.5(3) A(3), Z = 4. Compound 1 is a three-dimensional network made up of malonate-bridged gadolinium(III) ions where the malonate exhibits two bridging modes, eta(5)-bidentate + unidentate and eta(3):eta(3) + bis(unidentate). The gadolinium atom is nine-coordinate with three water molecules and six malonate oxygen atoms from three malonate ligands forming a distorted monocapped square antiprism. The shortest metal-metal separations are 4.2763(3) A [through the oxo-carboxylate bridge] and 6.541(3) A [through the carboxylate in the anti-syn coordination mode]. The value of the angle at the oxo-carboxylate atom is 116.8(2) degrees. Variable-temperature magnetic susceptibility measurements reveal the occurrence of a significant ferromagnetic interaction through the oxo-carboxylate pathway (J = +0.048(1) cm(-1), H = -JS(Gd(1)) x S(Gd(1a))).
[Study on triterpenes of Microtropis tiflora].

PubMed

Wang, Kui-wu; Hu, Xin-ling; Shen, Lian-qing; Pan, Yuan-jiang

2007-08-01

To study the chemical constituents of Microtropis triflora. The compounds were isolated by chromatography on silica gel and Sephadex LH-20. There structures were elucidatedby by chemical methods and spectral analysis. Five triterpenoids were isolated and elucidated as friedelin (1), 3-oxo-28-friedelanoic acid (2), 29-hydroxy-3-friedelanone (3), salaspermic acid (4), orthosphenic acid (5). Compounds 1-5 are all isolated from M. triflora for the first time.
40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...
40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...
40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...
Biosynthesis of Cutin

PubMed Central

Kolattukudy, P.E.; Croteau, Rodney; Walton, T.J.

1975-01-01

Long chain dicarboxylic acids are constituents of the protective biopolymers cutin and suberin of plants. Cell-free extracts from the excised epidermis of Vicia faba leaves catalyzed conversion of 16-hydroxy[G-3H]hexadecanoic acid to the corresponding dicarboxylic acid with nicotinamide-adenine dinucleotide phosphate as the preferred cofactor. This enzymatic activity, located largely in the 100,000g supernatant fraction, had a pH optimum near 8. This dehydrogenase showed an apparent Km of 1.25 × 10−5m and 3.6 × 10−4m for 16-hydroxyhexadecanoic acid and NADP, respectively. Modification of the substrate, either by esterification of the carboxyl group or by introduction of another hydroxyl group at C-10, resulted in a substantial (two-thirds) decrease in the rate of reaction, and hexadecanol was not a good substrate. The enzyme was inhibited by thiol reagents such as N-ethylmaleimide and p-chloromercuribenzoate. The aldehyde intermediate was trapped by the inclusion of dinitrophenyl hydrazine in the reaction mixture, and the 16-oxo compound was regenerated and identified. Furthermore, synthetic 16-oxo-[G-3H] hexadecanoic acid was readily converted to the dicarboxylic acid by the cell-free preparation. These results demonstrate that epidermis of Vicia faba contains an ω-hydroxyacid dehydrogenase and an ω-oxoacid dehydrogenase. PMID:16659184
Chloromonilinic Acids C and D, Phytotoxic Tetrasubstituted 3-Chromanonacrylic Acids Isolated from Cochliobolus australiensis with Potential Herbicidal Activity against Buffelgrass (Cenchrus ciliaris).

PubMed

Masi, Marco; Meyer, Susan; Clement, Suzette; Pescitelli, Gennaro; Cimmino, Alessio; Cristofaro, Massimo; Evidente, Antonio

2017-10-27

The fungal pathogen Cochliobolus australiensis isolated from infected leaves of the invasive weed buffelgrass (Pennisetum ciliare) was grown in vitro to evaluate its ability to produce phytotoxic metabolites that could potentially be used as natural herbicides against this weed. Two new tetrasubstituted 3-chromanonacrylic acids, named chloromonilinic acids C (1) and D (2), were isolated from the liquid cultures of C. australiensis, together with the known chloromonilinic acid B. Chloromonilinic acids C and D were characterized by spectroscopic and chemical methods as (E)-3-chloro-3-[(5-hydroxy-3-(1-hydroxy-2-methoxy-2-oxoethyl)-7-methyl-4-oxo-4H-chromen-2-yl)]acrylic acid and (Z)-3-chloro-3-[(5-hydroxy-3-(2-methoxy-2-oxoethyl)-7-methyl-4-oxo-4H-chromen-2-yl)]acrylic acid, respectively. The stereochemistry of chloromonilinic acids C and D was determined using a combination of spectroscopic and computational methods, including electronic circular dichroism. The fungus produced these compounds in two different liquid media together with cochliotoxin, radicinin, radicinol, and their 3-epimers. The radicinin-related compounds were also produced when the fungus was grown in wheat seed solid culture, but chloromonilinic acids were not found in the solid culture organic extract. All three chloromonilinic acids were toxic to buffelgrass in a seedling elongation bioassay, with significantly delayed germination and dramatically reduced radicle growth, especially at a concentration of 5 × 10 -3 M.
Lower glutamic acid decarboxylase 65-kDa isoform messenger RNA and protein levels in the prefrontal cortex in schizoaffective disorder but not schizophrenia.

PubMed

Glausier, Jill R; Kimoto, Sohei; Fish, Kenneth N; Lewis, David A

2015-01-15

Altered gamma-aminobutyric acid (GABA) signaling in the prefrontal cortex (PFC) has been associated with cognitive dysfunction in patients with schizophrenia and schizoaffective disorder. Levels of the GABA-synthesizing enzyme glutamic acid decarboxylase 67-kDa isoform (GAD67) in the PFC have been consistently reported to be lower in patients with these disorders, but the status of the second GABA-synthesizing enzyme, glutamic acid decarboxylase 65-kDa isoform (GAD65), remains unclear. GAD65 messenger RNA (mRNA) levels were quantified in PFC area 9 by quantitative polymerase chain reaction from 62 subjects with schizophrenia or schizoaffective disorder and 62 matched healthy comparison subjects. In a subset of subject pairs, GAD65 relative protein levels were quantified by confocal immunofluorescence microscopy. Mean GAD65 mRNA levels were 13.6% lower in subjects with schizoaffective disorder but did not differ in subjects with schizophrenia relative to their matched healthy comparison subjects. In the subjects with schizoaffective disorder, mean GAD65 protein levels were 19.4% lower and were correlated with GAD65 mRNA levels. Lower GAD65 mRNA and protein levels within subjects with schizoaffective disorder were not attributable to factors commonly comorbid with the diagnosis. In concert with previous studies, these findings suggest that schizoaffective disorder is associated with lower levels of both GAD65 and GAD67 mRNA and protein in the PFC, whereas subjects with schizophrenia have lower mean levels of only GAD67 mRNA and protein. Because cognitive function is generally better preserved in patients with schizoaffective disorder relative to patients with schizophrenia, these findings may support an interpretation that GAD65 downregulation provides a homeostatic response complementary to GAD67 downregulation that serves to reduce inhibition in the face of lower PFC network activity. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
Indole-3-acetic acid modulates phytohormones and polyamines metabolism associated with the tolerance to water stress in white clover.

PubMed

Li, Zhou; Li, Yaping; Zhang, Yan; Cheng, Bizhen; Peng, Yan; Zhang, Xinquan; Ma, Xiao; Huang, Linkai; Yan, Yanhong

2018-06-09

Endogenous hormones and polyamines (PAs) could interact to regulate growth and tolerance to water stress in white clover. The objective of this study was to investigate whether the alteration of endogenous indole-3-acetic acid (IAA) level affected other hormones level and PAs metabolism contributing to the regulation of tolerance to water stress in white clover. Plants were pretreated with IAA or L-2-aminooxy-3-phenylpropionic acid (L-AOPP, the inhibitor of IAA biosynthesis) for 3 days and then subjected to water-sufficient condition and water stress induced by 15% polyethylene glycol 6000 for 8 days in growth chambers. Exogenous application of IAA significantly increased endogenous IAA, gibberellin (GA), abscisic acid (ABA), and polyamine (PAs) levels, but had no effect on cytokinin content under water stress. The increase in endogenous IAA level enhanced PAs anabolism via the improvement of enzyme activities and transcript level of genes including arginine decarboxylase, ornithine decarboxylase, and S-adenosylmethionine decarboxylase. Exogenous application of IAA also affected PAs catabolism, as manifested by an increase in diamine oxidase and a decrease in polyamine oxidase activities and genes expression. More importantly, the IAA deficiency in white clover decreased endogenous hormone levels (GA, ABA, and PAs) and PAs anabolism along with decline in antioxidant defense and osmotic adjustment (OA). On the contrary, exogenous IAA effectively alleviated stress-induced oxidative damage, growth inhibition, water deficit, and leaf senescence through the maintenance of higher chlorophyll content, OA, and antioxidant defense as well as lower transcript levels of senescence marker genes SAG101 and SAG102 in leaves under water stress. These results indicate that IAA-induced the crosstalk between endogenous hormones and PAs could be involved in the improvement of antioxidant defense and OA conferring tolerance to water stress in white clover. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
Glutamic Acid Decarboxylase in Kitten Striate Cortex.

DTIC Science & Technology

1985-03-22

principle of protein dye binding. Burchfiel, J.L. & F.H. Duffy (1981) Role of intracortical inhibition in deprivation amblyopia : Reversal by...Burchfiel & J.L. Conway (1976) Bicuculline reversal of deprivation amblyopia in the cat. Nature 260: 256-257. Einstein, G., T.L. Davis & P. Sterling (1983
Spotlight on opicapone as an adjunct to levodopa in Parkinson’s disease: design, development and potential place in therapy

PubMed Central

Annus, Ádám; Vécsei, László

2017-01-01

Parkinson’s disease (PD) is a progressive, chronic, neurodegenerative disease characterized by rigidity, tremor, bradykinesia and postural instability secondary to dopaminergic deficit in the nigrostriatal system. Currently, disease-modifying therapies are not available, and levodopa (LD) treatment remains the gold standard for controlling motor and nonmotor symptoms of the disease. LD is extensively and rapidly metabolized by peripheral enzymes, namely, aromatic amino acid decarboxylase and catechol-O-methyltransferase (COMT). To increase the bioavailability of LD, COMT inhibitors are frequently used in clinical settings. Opicapone is a novel COMT inhibitor that has been recently approved by the European Medicines Agency as an adjunctive therapy to combinations of LD and aromatic amino acid decarboxylase inhibitor in adult PD patients with end-of-dose motor fluctuations. We aimed to review the biochemical properties of opicapone, summarize its preclinical and clinical trials and discuss its future potential role in the treatment of PD. PMID:28123288

Syndromic intellectual disability: a new phenotype caused by an aromatic amino acid decarboxylase gene (DDC) variant.

PubMed

Graziano, Claudio; Wischmeijer, Anita; Pippucci, Tommaso; Fusco, Carlo; Diquigiovanni, Chiara; Nõukas, Margit; Sauk, Martin; Kurg, Ants; Rivieri, Francesca; Blau, Nenad; Hoffmann, Georg F; Chaubey, Alka; Schwartz, Charles E; Romeo, Giovanni; Bonora, Elena; Garavelli, Livia; Seri, Marco

2015-04-01

The causative variant in a consanguineous family in which the three patients (two siblings and a cousin) presented with intellectual disability, Marfanoid habitus, craniofacial dysmorphisms, chronic diarrhea and progressive kyphoscoliosis, has been identified through whole exome sequencing (WES) analysis. WES study identified a homozygous DDC variant in the patients, c.1123C>T, resulting in p.Arg375Cys missense substitution. Mutations in DDC cause a recessive metabolic disorder (aromatic amino acid decarboxylase, AADC, deficiency, OMIM #608643) characterized by hypotonia, oculogyric crises, excessive sweating, temperature instability, dystonia, severe neurologic dysfunction in infancy, and specific abnormalities of neurotransmitters and their metabolites in the cerebrospinal fluid (CSF). In our family, analysis of neurotransmitters and their metabolites in patient's CSF shows a pattern compatible with AADC deficiency, although the clinical signs are different from the classic form. Our work expands the phenotypic spectrum associated with DDC variants, which therefore can cause an additional novel syndrome without typical movement abnormalities. Copyright © 2015 Elsevier B.V. All rights reserved.
Cloning and characterization of the ddc homolog encoding L-2,4-diaminobutyrate decarboxylase in Enterobacter aerogenes.

PubMed

Yamamoto, S; Mutoh, N; Tsuzuki, D; Ikai, H; Nakao, H; Shinoda, S; Narimatsu, S; Miyoshi, S I

2000-05-01

L-2,4-diaminobutyrate decarboxylase (DABA DC) catalyzes the formation of 1,3-diaminopropane (DAP) from DABA. In the present study, the ddc gene encoding DABA DC from Enterobacter aerogenes ATCC 13048 was cloned and characterized. Determination of the nucleotide sequence revealed an open reading frame of 1470 bp encoding a 53659-Da protein of 490 amino acids, whose deduced NH2-terminal sequence was identical to that of purified DABA DC from E. aerogenes. The deduced amino acid sequence was highly similar to those of Acinetobacter baumannii and Haemophilus influenzae DABA DCs encoded by the ddc genes. The lysine-307 of the E. aerogenes DABA DC was identified as the pyridoxal 5'-phosphate binding residue by site-directed mutagenesis. Furthermore, PCR analysis revealed the distribution of E. aerogenes ddc homologs in some other species of Enterobacteriaceae. Such a relatively wide occurrence of the ddc homologs implies biological significance of DABA DC and its product DAP.
Exogenous γ-aminobutyric acid (GABA) affects pollen tube growth via modulating putative Ca2+-permeable membrane channels and is coupled to negative regulation on glutamate decarboxylase

PubMed Central

Yu, Guang-Hui; Zou, Jie; Feng, Jing; Peng, Xiong-Bo; Wu, Ju-You; Wu, Ying-Liang; Palanivelu, Ravishankar; Sun, Meng-Xiang

2014-01-01

γ-Aminobutyric acid (GABA) is implicated in pollen tube growth, but the molecular and cellular mechanisms that it mediates are largely unknown. Here, it is shown that exogenous GABA modulates putative Ca2+-permeable channels on the plasma membranes of tobacco pollen grains and pollen tubes. Whole-cell voltage-clamp experiments and non-invasive micromeasurement technology (NMT) revealed that the influx of Ca2+ increases in pollen tubes in response to exogenous GABA. It is also demonstrated that glutamate decarboxylase (GAD), the rate-limiting enzyme of GABA biosynthesis, is involved in feedback controls of Ca2+-permeable channels to fluctuate intracellular GABA levels and thus modulate pollen tube growth. The findings suggest that GAD activity linked with Ca2+-permeable channels relays an extracellular GABA signal and integrates multiple signal pathways to modulate tobacco pollen tube growth. Thus, the data explain how GABA mediates the communication between the style and the growing pollen tubes. PMID:24799560
The use of modified and non-natural nucleotides provide unique insights into pro-mutagenic replication catalyzed by polymerase eta.

PubMed

Choi, Jung-Suk; Dasari, Anvesh; Hu, Peter; Benkovic, Stephen J; Berdis, Anthony J

2016-02-18

This report evaluates the pro-mutagenic behavior of 8-oxo-guanine (8-oxo-G) by quantifying the ability of high-fidelity and specialized DNA polymerases to incorporate natural and modified nucleotides opposite this lesion. Although high-fidelity DNA polymerases such as pol δ and the bacteriophage T4 DNA polymerase replicating 8-oxo-G in an error-prone manner, they display remarkably low efficiencies for TLS compared to normal DNA synthesis. In contrast, pol η shows a combination of high efficiency and low fidelity when replicating 8-oxo-G. These combined properties are consistent with a pro-mutagenic role for pol η when replicating this DNA lesion. Studies using modified nucleotide analogs show that pol η relies heavily on hydrogen-bonding interactions during translesion DNA synthesis. However, nucleobase modifications such as alkylation to the N2 position of guanine significantly increase error-prone synthesis catalyzed by pol η when replicating 8-oxo-G. Molecular modeling studies demonstrate the existence of a hydrophobic pocket in pol η that participates in the increased utilization of certain hydrophobic nucleotides. A model is proposed for enhanced pro-mutagenic replication catalyzed by pol η that couples efficient incorporation of damaged nucleotides opposite oxidized DNA lesions created by reactive oxygen species. The biological implications of this model toward increasing mutagenic events in lung cancer are discussed. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
Metabolomic Analysis of the Secretome of Human Embryonic Stem Cells Following Methyl Parathion and Methyl Paraoxon Exposure Phase 2: Metabolite Downselection for Structural Confirmation

DTIC Science & Technology

2013-12-01

degradation 2 Pipecolic acid II 2-keto-6- aminocaproate II Pyruvate metabolism 1 Malic acid I Purine metabolism 1 Guanine I Propanoate metabolism 1...acetamidobutanoic acid II cis-4-hydroxy-D-proline II D-arginine and D-ornithine metabolism 4 Ornithine II 5-amino-2-oxopentanoic acid II 2-amino-4-oxo...pentanoic acid II (2R,4S)-2,4-diaminopentanoate II Gly, Ser, and Thr metabolism 3 L-cystathionine II Choline II 5-aminolevulinic acid II Val
Regio- and Stereoselective Aliphatic-Aromatic Cross-Benzoin Reaction: Enzymatic Divergent Catalysis.

PubMed

Beigi, Maryam; Gauchenova, Ekaterina; Walter, Lydia; Waltzer, Simon; Bonina, Fabrizio; Stillger, Thomas; Rother, Dörte; Pohl, Martina; Müller, Michael

2016-09-19

The catalytic asymmetric synthesis of chiral 2-hydroxy ketones by using different thiamine diphosphate dependent enzymes, namely benzaldehyde lyase from Pseudomonas fluorescens (PfBAL), a variant of benzoylformate decarboxylase from Pseudomonas putida (PpBFD-L461A), branched-chain 2-keto acid decarboxylase from Lactococcus lactis (LlKdcA) and a variant of pyruvate decarboxylase from Acetobacter pasteurianus (ApPDC-E469G), was studied. Starting with the same set of substrates, substituted benzaldehydes in combination with different aliphatic aldehydes, PfBAL and PpBFD-L461A selectively deliver the (R)- and (S)-2-hydroxy-propiophenone derivatives, respectively. The (R)- and (S)-phenylacetylcarbinol (1-hydroxy-1-phenylacetone) derivatives are accessible in a similar way using LlKdcA and ApPDC-E469G, respectively. In many cases excellent stereochemical purities (>98 % enantiomeric excess) could be achieved. Hence, the regio- and stereochemistry of the product in the asymmetric aliphatic-aromatic cross-benzoin reaction can be controlled solely by choice of the appropriate enzyme or enzyme variant. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Molecular and physiological comparison of spoilage wine yeasts.

PubMed

Sangorrín, M P; García, V; Lopes, C A; Sáez, J S; Martínez, C; Ganga, M A

2013-04-01

Dekkera bruxellensis and Pichia guilliermondii are contaminating yeasts in wine due to the production of phenolic aromas. Although the degradation pathway of cinnamic acids, precursors of these phenolic compounds has been described in D. bruxellensis, no such pathway has been described in P. guilliermondii. A molecular and physiological characterization of 14 D. bruxellensis and 15 P. guilliermondii phenol-producing strains was carried out. Both p-coumarate decarboxylase (CD) and vinyl reductase (VR) activities, responsible for the production of volatile phenols, were quantified and the production of 4-vinylphenol and 4-ethylphenol were measured. All D. bruxellensis and some P. guilliermondii strains showed the two enzymatic activities, whilst 11 of the 15 strains of this latter species showed only CD activity and did not produce 4-EP in the assay conditions. Furthermore, PCR products obtained with degenerated primers showed a low homology with the sequence of the gene for a phenyl acrylic acid decarboxylase activity described in Saccharomyces cerevisiae. D. bruxellensis and P. guilliermondii may share a similar metabolic pathway for the degradation of cinnamic acids. This is the first work that analyses the CD and VR activities in P. guilliermondii, and the results suggest that within this species, there are differences in the metabolization of cinnamic acids. © 2013 The Society for Applied Microbiology.
Integrating metabolomics and transcriptomics data to discover a biocatalyst that can generate the amine precursors for alkamide biosynthesis

PubMed Central

Rizhsky, Ludmila; Jin, Huanan; Shepard, Michael R.; Scott, Harry W.; Teitgen, Alicen M.; Perera, M. Ann; Mhaske, Vandana; Jose, Adarsh; Zheng, Xiaobin; Crispin, Matt; Wurtele, Eve S.; Jones, Dallas; Hur, Manhoi; Góngora-Castillo, Elsa; Buell, C. Robin; Minto, Robert E.; Nikolau, Basil J.

2016-01-01

Summary The Echinacea genus is exemplary of over 30 plant families that produce a set of bioactive amides, called alkamides. The Echinacea alkamides may be assembled from two distinct moieties, a branched-chain amine that is acylated with a novel polyunsaturated fatty acid. In this study we identified the potential enzymological source of the amine moiety as a pyridoxal phosphate dependent decarboxylating enzyme that uses branched chain amino acids as substrate. This identification was based on a correlative analysis of the transcriptomes and metabolomes of 36 different E. purpurea tissues and organs, which expressed distinct alkamide profiles. Although no correlation was found between the accumulation patterns of the alkamides and their putative metabolic precursors (i.e., fatty acids and branched chain amino acids), isotope-labeling analyses supported the transformation of valine and isoleucine to isobutylamine and 2-methylbutylamine as reactions of alkamide biosynthesis. Sequence homology identified the pyridoxal phosphate dependent decarboxylase-like proteins in the translated proteome of E. purpurea. These sequences were prioritized for direct characterization by correlating their transcript levels with alkamide accumulation patterns in different organs and tissues, and this multi-pronged approach led to the identification and characterization of a branched-chain amino acid decarboxylase, which would appear to be responsible for generating the amine moieties of naturally occurring alkamides. PMID:27497272
Polyamine metabolism and osmotic stress. II. Improvement of oat protoplasts by an inhibitor of arginine decarboxylase

NASA Technical Reports Server (NTRS)

Tiburcio, A. F.; Kaur-Sawhney, R.; Galston, A. W.

1986-01-01

We have attempted to improve the viability of cereal mesophyll protoplasts by pretreatment of leaves with DL-alpha-difluoromethylarginine (DFMA), a specific 'suicide' inhibitor of the enzyme (arginine decarboxylase) responsible for their osmotically induced putrescine accumulation. Leaf pretreatment with DFMA before a 6 hour osmotic shock caused a 45% decrease of putrescine and a 2-fold increase of spermine titer. After 136 hours of osmotic stress, putrescine titer in DFMA-pretreated leaves increased by only 50%, but spermidine and spermine titers increased dramatically by 3.2- and 6-fold, respectively. These increases in higher polyamines could account for the reduced chlorophyll loss and enhanced ability of pretreated leaves to incorporate tritiated thymidine, uridine, and leucine into macromolecules. Pretreatment with DFMA significantly improved the overall viability of the protoplasts isolated from these leaves. The results support the view that the osmotically induced rise in putrescine and blockage of its conversion to higher polyamines may contribute to the lack of sustained cell division in cereal mesophyll protoplasts, although other undefined factors must also play a major role.
Kinetic studies on the control of the bean rust fungus (Uromyces phaseoli L.) by an inhibitor of polyamine biosynthesis

NASA Technical Reports Server (NTRS)

Rajam, M. V.; Weinstein, L. H.; Galston, A. W.

1986-01-01

alpha-Difluoromethylornithine (DFMO), a specific and irreversible inhibitor of the polyamine biosynthetic enzyme ornithine decarboxylase, effectively inhibits mycelial growth of several phytopathogenic fungi on defined media in vitro and provides systemic protection of bean plants against infection by Uromyces phaseoli L. race 0 (MV Rajam, AW Galston 1985 Plant Cell Physiol 26: 683-692; MV Rajam et al. 1985 Proc Natl Acad Sci USA 82: 6874-6878). We now find that application of 0.5 millimolar DFMO to unifoliolate leaves of Pinto beans up to 3 days after inoculation with uredospores of U. phaseoli completely inhibits the growth of the pathogen, while application 4 or 5 days after inoculation results in partial protection against the pathogen. Spores do not germinate on the surface of unifoliolate leaves treated with DFMO 1 day before infection, but addition of spermidine to the DFMO treatments partially reverses the inhibitory effect. The titer of polyamines in bean plants did not decline after DFMO treatment; rather, putrescine and spermidine contents actually rose, probably due to the known but paradoxical stimulation of arginine decarboxylase activity by DFMO.
Chemical modification of L-glutamine to alpha-amino glutarimide on autoclaving facilitates Agrobacterium infection of host and non-host plants: A new use of a known compound

PubMed Central

2011-01-01

Background Accidental autoclaving of L-glutamine was found to facilitate the Agrobacterium infection of a non host plant like tea in an earlier study. In the present communication, we elucidate the structural changes in L-glutamine due to autoclaving and also confirm the role of heat transformed L-glutamine in Agrobacterium mediated genetic transformation of host/non host plants. Results When autoclaved at 121°C and 15 psi for 20 or 40 min, L-glutamine was structurally modified into 5-oxo proline and 3-amino glutarimide (α-amino glutarimide), respectively. Of the two autoclaved products, only α-amino glutarimide facilitated Agrobacterium infection of a number of resistant to susceptible plants. However, the compound did not have any vir gene inducing property. Conclusions We report a one pot autoclave process for the synthesis of 5-oxo proline and α-amino glutarimide from L-glutamine. Xenobiotic detoxifying property of α-amino glutarimide is also proposed. PMID:21624145
Biosynthesis of allene oxides in Physcomitrella patens

PubMed Central

2012-01-01

Background The moss Physcomitrella patens contains C18- as well as C20-polyunsaturated fatty acids that can be metabolized by different enzymes to form oxylipins such as the cyclopentenone cis(+)-12-oxo phytodienoic acid. Mutants defective in the biosynthesis of cyclopentenones showed reduced fertility, aberrant sporophyte morphology and interrupted sporogenesis. The initial step in this biosynthetic route is the conversion of a fatty acid hydroperoxide to an allene oxide. This reaction is catalyzed by allene oxide synthase (AOS) belonging as hydroperoxide lyase (HPL) to the cytochrome P450 family Cyp74. In this study we characterized two AOS from P. patens, PpAOS1 and PpAOS2. Results Our results show that PpAOS1 is highly active with both C18 and C20-hydroperoxy-fatty acid substrates, whereas PpAOS2 is fully active only with C20-substrates, exhibiting trace activity (~1000-fold lower kcat/KM) with C18 substrates. Analysis of products of PpAOS1 and PpHPL further demonstrated that both enzymes have an inherent side activity mirroring the close inter-connection of AOS and HPL catalysis. By employing site directed mutagenesis we provide evidence that single amino acid residues in the active site are also determining the catalytic activity of a 9-/13-AOS – a finding that previously has only been reported for substrate specific 13-AOS. However, PpHPL cannot be converted into an AOS by exchanging the same determinant. Localization studies using YFP-labeled AOS showed that PpAOS2 is localized in the plastid while PpAOS1 may be found in the cytosol. Analysis of the wound-induced cis(+)-12-oxo phytodienoic acid accumulation in PpAOS1 and PpAOS2 single knock-out mutants showed that disruption of PpAOS1, in contrast to PpAOS2, results in a significantly decreased cis(+)-12-oxo phytodienoic acid formation. However, the knock-out mutants of neither PpAOS1 nor PpAOS2 showed reduced fertility, aberrant sporophyte morphology or interrupted sporogenesis. Conclusions Our study highlights five findings regarding the oxylipin metabolism in P. patens: (i) Both AOS isoforms are capable of metabolizing C18- and C20-derived substrates with different specificities suggesting that both enzymes might have different functions. (ii) Site directed mutagenesis demonstrated that the catalytic trajectories of 9-/13-PpAOS1 and PpHPL are closely inter-connected and PpAOS1 can be inter-converted by a single amino acid exchange into a HPL. (iii) In contrast to PpAOS1, PpAOS2 is localized in the plastid where oxylipin metabolism takes place. (iv) PpAOS1 is essential for wound-induced accumulation of cis(+)-12-oxo phytodienoic acid while PpAOS2 appears not to be involved in the process. (v) Knock-out mutants of neither AOS showed a deviating morphological phenotype suggesting that there are overlapping functions with other Cyp74 enzymes. PMID:23194461
Proteomic Analysis of Calcium Effects on Soybean Root Tip under Flooding and Drought Stresses.

PubMed

Wang, Xin; Komatsu, Setsuko

2017-08-01

Flooding and drought are disadvantageous environmental conditions that induce cytosolic calcium in soybean. To explore the effects of flooding- and drought-induced increases in calcium, a gel-free/label-free proteomic analysis was performed. Cytosolic calcium was decreased by blocking calcium channels in the endoplasmic reticulum (ER) and plasma membrane under both stresses. Calnexin, protein disulfide isomerase, heat shock proteins and thioredoxin were predominantly affected as the ER proteins in response to calcium, and ER-associated degradation-related proteins of HCP-like superfamily protein were up-regulated under stress exposure and then down-regulated. Glycolysis, fermentation, the tricarboxylic acid cycle and amino acid metabolism were mainly induced as the types of cellular metabolism in response to calcium under both stresses. Pyruvate decarboxylase was increased and decreased under flooding and drought, respectively, and was further decreased by the reduction of cytosolic calcium; however, it was recovered by exogenous calcium under both stresses. Furthermore, pyruvate decarboxylase activity was increased under flooding, but decreased under drought. These results suggest that calcium is involved in protein folding in the ER, and ER-associated degradation might alleviate ER stress during the early stage of both stresses. Furthermore, calcium appears to modify energy metabolism, and pyruvate decarboxylase may be a key enzyme in this process under flooding and drought. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.
First evidence of a membrane-bound, tyramine and beta-phenylethylamine producing, tyrosine decarboxylase in Enterococcus faecalis: a two-dimensional electrophoresis proteomic study.

PubMed

Pessione, Enrica; Pessione, Alessandro; Lamberti, Cristina; Coïsson, Daniel Jean; Riedel, Kathrin; Mazzoli, Roberto; Bonetta, Silvia; Eberl, Leo; Giunta, Carlo

2009-05-01

The soluble and membrane proteome of a tyramine producing Enterococcus faecalis, isolated from an Italian goat cheese, was investigated. A detailed analysis revealed that this strain also produces small amounts of beta-phenylethylamine. Kinetics of tyramine and beta-phenylethylamine accumulation, evaluated in tyrosine plus phenylalanine-enriched cultures (stimulated condition), suggest that the same enzyme, the tyrosine decarboxylase (TDC), catalyzes both tyrosine and phenylalanine decarboxylation: tyrosine was recognized as the first substrate and completely converted into tyramine (100% yield) while phenylalanine was decarboxylated to beta-phenylethylamine (10% yield) only when tyrosine was completely depleted. The presence of an aspecific aromatic amino acid decarboxylase is a common feature in eukaryotes, but in bacteria only indirect evidences of a phenylalanine decarboxylating TDC have been presented so far. Comparative proteomic investigations, performed by 2-DE and MALDI-TOF/TOF MS, on bacteria grown in conditions stimulating tyramine and beta-phenylethylamine biosynthesis and in control conditions revealed 49 differentially expressed proteins. Except for aromatic amino acid biosynthetic enzymes, no significant down-regulation of the central metabolic pathways was observed in stimulated conditions, suggesting that tyrosine decarboxylation does not compete with the other energy-supplying routes. The most interesting finding is a membrane-bound TDC highly over-expressed during amine production. This is the first evidence of a true membrane-bound TDC, longly suspected in bacteria on the basis of the gene sequence.
Genetics Home Reference: aromatic l-amino acid decarboxylase deficiency

MedlinePlus

... Nov 18. Review. Citation on PubMed Pearl PL, Taylor JL, Trzcinski S, Sokohl A. The pediatric neurotransmitter disorders. J Child Neurol. 2007 May;22(5):606-16. Review. Citation on PubMed Pons R, Ford B, Chiriboga CA, Clayton PT, Hinton V, Hyland K, ...
Molecular water oxidation catalyst

DOEpatents

Gratzel, Michael; Munavalli, Shekhar; Pern, Fu-Jann; Frank, Arthur J.

1993-01-01

A dimeric composition of the formula: ##STR1## wherein L', L", L'", and L"" are each a bidentate ligand having at least one functional substituent, the ligand selected from bipyridine, phenanthroline, 2-phenylpyridine, bipyrimidine, and bipyrazyl and the functional substituent selected from carboxylic acid, ester, amide, halogenide, anhydride, acyl ketone, alkyl ketone, acid chloride, sulfonic acid, phosphonic acid, and nitro and nitroso groups. An electrochemical oxidation process for the production of the above functionally substituted bidentate ligand diaqua oxo-bridged ruthenium dimers and their use as water oxidation catalysts is described.
Structure-Guided Engineering of α-Keto Acid Decarboxylase for the Production of Higher Alcohols at Elevated Temperature.

PubMed

Sutiono, Samuel; Carsten, Jörg; Sieber, Volker

2018-06-28

Branched chain keto acid decarboxylases (KDCs) are a class of enzymes that catalyze the decarboxylation of α-keto acids. It is a key enzyme for production of higher alcohols in vivo and in vitro. However, the two most active KDCs (KivD and KdcA) have only moderate thermostability (<55 °C) hindering the production of the alcohols at high temperatures. In this study, structure-guided engineering toward improved thermostability of KdcA is outlined. Several strategies such as, stabilization of the catalytic center, surface engineering, and optimization of dimer interactions were applied. With 7 point mutations, our mutant (7M.D) showed an increase of T501h by 14.8 °C without compromising its substrate specificity. 7M.D exhibited >400-fold improvement of half-life at 70 °C and >600-fold increase in process stability in the presence of 4 % isobutanol at 50 °C. 7M.D is more promising for the production of higher alcohols in thermophiles (>65 °C) as well as in cell-free applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Blood-brain barrier transport of the alpha-keto acid analogs of amino acids.

PubMed

Steele, R D

1986-06-01

A number of alpha-keto acid analogs of amino acids have been found to penetrate the blood-brain barrier (BBB). Pyruvate, alpha-ketobutyrate, alpha-ketoisocaproate, and alpha-keto-gamma-methiolbutyrate all cross the BBB by a carrier-mediated process and by simple diffusion. Under normal physiological conditions, diffusion accounts for roughly 15% or less of total transport. Aromatic alpha-keto acids, phenylpyruvate, and p-hydroxyphenylpyruvate do not penetrate the BBB, nor do they inhibit the transport of other alpha-keto acids. Evidence based primarily on inhibition studies indicates that the carrier-mediated transport of alpha-keto acids occurs via the same carrier demonstrated previously for propionate, acetoacetate, and beta-hydroxybutyrate transport, commonly referred to as the monocarboxylate carrier. As a group, the alpha-keto acid analogs of the amino acids have the highest affinity for the carrier, followed by propionate and beta-hydroxybutyrate. Starvation for 4 days induces transport of alpha-keto acids, but transport is suppressed in rats fed commercial laboratory rations and subjected to portacaval shunts. The mitochondrial pyruvate translocator inhibitor alpha-cyanocinnamate has no effect on the BBB transport of alpha-keto acids.
Characterization of metabolic network of oxalic acid biosynthesis through RNA seq data analysis of developing spikes of finger millet (Eleusine coracana): Deciphering the role of key genes involved in oxalate formation in relation to grain calcium accumulation.

PubMed

Akbar, Naved; Gupta, Supriya; Tiwari, Apoorv; Singh, K P; Kumar, Anil

2018-04-05

In the present study, we identified seven major genes of oxalic acid biosynthesis pathway (SGAT, GGAT, ICL, GLO, MHAR, APO and OXO) from developing spike transcriptome of finger millet using rice as a reference. Sequence alignment of identified genes showed high similarity with their respective homolog in rice except for OXO and GLO. Transcript abundance (FPKM) reflects the higher accumulation of identified genes in GP-1 (low calcium genotype) as compared to GP-45 (high calcium genotype) which was further confirmed by qRT-PCR analysis, indicating differential oxalate formation in both genotypes. Determination of oxalic acid and tartaric acid content in developing spikes explain that higher oxalic acid content in GP-1 however, tartaric acid content was more in GP-45. Higher calcium content in GP-45 and lower oxalate accumulation may be due to the diversion of more ascorbic acid into tartaric acid and may correspond to less formation of calcium oxalate. Our results suggest that more than one pathway for oxalic acid biosynthesis might be present in finger millet with probable predominance of ascorbate-tartarate pathway rather than glyoxalate-oxalate conversion. Thus, finger millet can be use as an excellent model system for understanding more specific role of nutrients-antinutrients interactions, as evident from the present study. Copyright © 2018 Elsevier B.V. All rights reserved.
Protonation-dissociation reactions of imazamethabenz-methyl and imazamethabenz-Acid in relation to their soil sorption and abiotic degradation.

PubMed

Pintado, Sara; Montoya, Mercedes Ruiz; Mellado, José Miguel Rodríguez

2009-12-09

This paper present ultraviolet-visible absorption spectra of imazamethabenz-methyl (IMBM) (mixture of the isomers methyl 6-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-m-toluate, m-imazamethabenz, and methyl 2-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-p-toluate, p-imazamethabenz) and the corresponding carboxylic acid, imazamethabenz-acid (IMBA). The spectral characteristics are determined as functions of the pH. The appreciable absorbance in the visible (or near-ultraviolet) region of the spectra indicates that the natural photolytic degradation is possible. From variations of the maximum absorbances of the bands, the pK values of 3.4 +/- 0.2 and 9.4 +/- 0.2 were obtained for protonation of the imidazol (=N-) nitrogen and dissociation of the NH imidazol nitrogen of IMBM, respectively. For IMBA, the dissociation pK of the carboxylic group is very close to that of the imidazol (=N-) nitrogen, both being close to 3.3. The dissociation pK of the NH imidazol nitrogen for IMBA is 9.6 +/- 0.2. The role of the acid-base reactions on the sorption on soils of these herbicides is discussed.

Antitumor activity of newly synthesized oxo and ethylidene derivatives of bile acids and their amides and oxazolines.

PubMed

Bjedov, Srđan; Jakimov, Dimitar; Pilipović, Ana; Poša, Mihalj; Sakač, Marija

2017-04-01

Bile acid derivatives with modifications in side chain and modifications on steroid skeleton were synthetized and their antitumor activity against five human cancer cell lines was investigated. Modifications in side chain include amid group, formed in reaction with 2-amino-2-methylpropanol, and 4,4-dimethyloxazoline group, obtained after cyclization of amides. In the steroid skeleton oxo groups were introduced in position 7 (2, 2a, 2b) and 7,12 (3, 3a, 3b). Ethylidene groups were introduced regio- and stereoselectively on C-7, and/or without stereoselectivity on C-3 by Wittig reaction. By combination of these modifications, a series of 19 bile acid derivatives were synthesized. Compounds containing both C-7 ethylidene and C-12 carbonyl groups (6, 6a, 6b) shown very good antitumor activity with IC 50 <5µM. Altering carboxylic group to amide or oxazoline group has positive effect on cytotoxicity. Different molecular descriptors were determined in silico and after principal component analysis was found that molecular descriptor BLTF96 can be used for fast assessment of experimental cytotoxicity of bile acid derivatives. Copyright © 2017 Elsevier Inc. All rights reserved.
Bowl adamanzanes--bicyclic tetraamines: syntheses and crystal structures of complexes with cobalt(III) and chelating coordinated oxo-anions.

PubMed

Broge, Louise; Søtofte, Inger; Jensen, Kristian; Jensen, Nicolai; Pretzmann, Ulla; Springborg, Johan

2007-09-14

Seven cobalt(III) complexes of the macrobicyclic tetraamine ligand [2(4).3(1)]adamanzane ([2(4).3(1)]adz) are reported along with the crystal structure of six of these complexes. The solid state and solution structures are discussed, and a detailed assignment of the NMR spectra of the sulfato complex is provided. Four of the seven complexes contain a chelate coordinating oxo-anion (sulfate, formiate, nitrate, carbonate). Equilibration of these species with the corresponding diaqua complex is generally slow. The rates of equilibration in 5 mol dm(-3) perchloric acid at 25 degrees C have been measured, yielding half lives of 20 min, 10 min and 3 h for the sulfato, formiato and carbonato species respectively. The corresponding reaction for the nitrato complex occurs with a half life of less than 3 min. The concentration acid dissociation constant for the Co([2(4).3(1)]adz)(HCO(3))(2+) ion has been measured to K(a) = 0.33 mol dm(-3) [25 degrees C, I = 2 mol dm(-3)] and K(a) = 0.15 mol dm(-3) [25 degrees C, I = 5 mol dm(-3)]. The propensity for coordination of sulfate was found to be large enough for a quantitative conversion of the carbonato complex to the sulfato complex to occur in 3 mol dm(-3) triflic acid containing a small sulfate contamination. On this basis the decarboxylation in 5 mol dm(-3) triflic acid of the corresponding cobalt(III) carbonato complex of the larger macrobicyclic tetraamine ligand [3(5)]adz was reinvestigated and found to lead to the sulfato complex as well. The difference in exchange rate of the oxo-anion ligands for the cobalt(III) complexes of the two adamanzane ligands is discussed and attributed to fundamental differences in the molecular structure where an inverted configuration of the secondary non-bridged amine groups is seen for the complexes of the larger [3(5)]adz ligand. The high affinity for chelating coordination of oxo-anions for these two cobalt(iii)-adamanzane-moieties is rationalised on basis of the N-Co-N angles. N-Co-N angles are compared for a series of adamanzane complexes, and the structural consequences are discussed.
Identification of a novel bile acid in swans, tree ducks, and geese: 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid.

PubMed

Kakiyama, Genta; Iida, Takashi; Goto, Takaaki; Mano, Nariyasu; Goto, Junichi; Nambara, Toshio; Hagey, Lee R; Schteingart, Claudio D; Hofmann, Alan F

2006-07-01

By HPLC, a taurine-conjugated bile acid with a retention time different from that of taurocholate was found to be present in the bile of the black-necked swan, Cygnus melanocoryphus. The bile acid was isolated and its structure, established by (1)H and (13)C NMR and mass spectrometry, was that of the taurine N-acyl amidate of 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid. The compound was shown to have chromatographic and spectroscopic properties that were identical to those of the taurine conjugate of authentic 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid, previously synthesized by us from ursodeoxycholic acid. By HPLC, the taurine conjugate of 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid was found to be present in 6 of 6 species in the subfamily Dendrocygninae (tree ducks) and in 10 of 13 species in the subfamily Anserinae (swans and geese) but not in other subfamilies in the Anatidae family. It was also not present in species from the other two families of the order Anseriformes. 3alpha,7alpha,15alpha-Trihydroxy-5beta-cholan-24-oic acid is a new primary bile acid that is present in the biliary bile acids of swans, tree ducks, and geese and may be termed 15alpha-hydroxy-chenodeoxycholic acid.
The ozonation of cholesterol: Separation and identification of 2,4-dinitrophenylhydrazine derivatization products of 3 beta-hydroxy-5-oxo-5,6-secocholestan-6-al

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, K.; Bermudez, E.; Pryor, W.A.

1993-05-01

The ozonation products of cholesterol, which are of interest as possible biomarkers of O3 exposure, were studied by derivatization with 2,4-dinitrophenylhydrazine (DNPH). The DNPH derivatization of 3 beta-hydroxy-5-oxo-5,6-secocholestan-6-al (2) produces the expected trans (3b) and cis (3c) derivatives of 3 beta-hydroxy-5-oxo-5,6-secocholestan-6-al, and the unexpected DNPH derivative of 3,5-dihydroxy-B-norcholestane-6-carboxaldehyde (3a). The structures of 3a, 3b, and 3c were identified with 1H nuclear magnetic resonance (NMR), 13C NMR, DEPT, COSY, and H-C correlation two-dimensional NMR techniques, and by comparison with the spectra of known compounds. A possible mechanism involving an enamine functionality is proposed for the formation of 3a. The ratio ofmore » 3a/(3b + 3c) depends on the concentration of acid used and the reaction time.« less
[Innovative application of small molecules to influence -pathogenicity of dental plaque].

PubMed

Janus, M M; Volgenant, C M C; Krom, B P

2018-05-01

Current preventive measures against infectious oral diseases are mainly focussed on plaque removal and promoting a healthy lifestyle. This in vitro study investigated a third preventive method: maintaining healthy dental plaque with the use of small molecules. As a model of dental plaque, in vitro biofilms were cultivated under conditions that induce pathogenic characteristics. The effect of erythritol and other small molecules on the pathogenic characteristics and bacterial composition of the biofilm was evaluated. The artificial sweetener erythritol and the molecule 3-Oxo-N-(2-oxycyclohexyl)dodecanamide (3-Oxo-N) had no clinically relevant effect on total biofilm formation. Erythritol did, however, lower the gingivitis related protease activity of the biofilm, while 3-Oxo-N blocked the caries related lactic acid accumulation. Furthermore, both substances ensured the biofilm maintained a young, non-pathogenic microbial composition. This shows it is possible to influence the dental plaque in a positive manner in vitro with the help of small molecules. Further research is necessary before this manipulation of dental plaque can be applied.
Characterization of the tumor-promoting activity of m-chloroperoxybenzoic acid in SENCAR mouse skin and its inhibition by gallotannin, oligomeric proanthocyanidin, and their monomeric units

Treesearch

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Fatima K. Johnson; Amy W. Davis; Steven W. Newell; Richard W. Hemingway; Vittorio Bottari; Jean-Pierre Perchellett

1996-01-01

m-Chloroperoxybenzoic acid (CPBA). Which induces ornithine decarboxylase activity as much as 12-0- terradecanoyIp horbol-13-acetate (TPA ). was tested for its ability to induce DNA synthesis. bydroperoxide (HPx) production. and tumor promotion in mouse epidermis in vivo. After an early inhibition. CPBA stimulates DNA synthesis. A response which is maintained between 16...
Two novel pyrrolooxazole pigments formed by the Maillard reaction between glucose and threonine or serine.

PubMed

Noda, Kyoko; Murata, Masatsune

2017-02-01

Pyrrolothiazolate formed by the Maillard reaction between l-cysteine and d-glucose has a pyrrolothiazole skeleton as a chromophore. We searched for a Maillard pigment having a pyrrolooxazole skeleton formed from l-threonine or l-serine instead of l-cysteine in the presence of d-glucose. As a result, two novel yellow pigments, named pyrrolooxazolates A and B, were isolated from model solutions of the Maillard reaction containing l-threonine and d-glucose, and l-serine and d-glucose, respectively, and identified as (2R,3S,7aS)-2,3,7,7a-tetrahydro-6-hydroxy-2,5,7a-trimethyl-7-oxo-pyrrolo[2,1-b]oxazole-3-calboxylic acid and (3S,7aS)-2,3,7,7a-tetrahydro-6-hydroxy-5,7a-dimethyl-7-oxo-pyrrolo[2,1-b]oxazole-3-calboxylic acid by instrumental analyses. These compounds were pyrrolooxazole derivatives carrying a carboxy group, and showed the absorption maxima at 300-360 nm under acidic and neutral conditions and at 320-390 nm under alkaline conditions.
Chemical constituents from Hericium erinaceus and their ability to stimulate NGF-mediated neurite outgrowth on PC12 cells.

PubMed

Zhang, Cheng-Chen; Yin, Xia; Cao, Chen-Yu; Wei, Jing; Zhang, Qiang; Gao, Jin-Ming

2015-11-15

One new meroterpenoid, named hericenone K (11), along with 10 known compounds (1-10), ergosterol peroxide (1), cerevisterol (2), 3β,5α,9α-trihydroxy-ergosta-7,22-dien-6-one (3), inoterpene A (4), astradoric acid C (5), betulin (6), oleanolic acid (7), ursolic acid (8), hemisceramide (9), and 3,4-dihydro-5-methoxy-2-methyl-2-(4'-methyl-2'-oxo-3'-pentenyl)-9(7H)-oxo-2H-furo[3,4-h]benzopyran (10), was isolated from the fruiting bodies of the mushroom Hericium erinaceus. Their structures were characterized on the basis of spectroscopic methods, as well as through comparison with previously reported data. Compounds 3-6, 8, and 9 were isolated from Hericium species for the first time. Compounds 10 and 11 was suggested to be racemic by the CD spectrum data and specific rotations, which ware resolved by chiral HPLC into respective enantiomers. Compounds 1-3, (±)-10, (-)-10 and (+)-10 in the presence of NGF (20 ng/mL) exerted a significant increase in neurite-bearing cells. Copyright © 2015 Elsevier Ltd. All rights reserved.
New fluorescent probes for visual proteins. Part II. 5-(Oxo)penta-2,4-dienyl-p-(N,N-dimethylamino)benzoate.

PubMed

Papper, Vladislav; Kharlanov, Vladimir; Schädel, Sandra; Maretzki, Dieter; Rettig, Wolfgang

2003-12-01

A new dual-fluorescent compound, 5-(oxo)penta-2,4-dienyl-p-(N,N-dimethylamino)benzoate (1), a derivative of dimethylaminobenzoic acid, has been synthesised and studied photophysically. This compound continues the series of potential fluorescent probes for visual and proton-pumping opsin proteins. The photophysical behaviour of this molecule, including charge-transfer interaction in the ground state and dual-fluorescence emission, is similar to that of the previously studied analogue cis-3-(oxo)propenyl-p-(N,N-dimethylamino)benzoate (cis-2). The presence of several theoretically calculated conformers of compound 2 was suggested to be responsible for the observed strongly red-shifted absorption and excitation wavelength dependence. These photophysical anomalies were also observed for molecule 1, though the models put forward to explain them in the cases of 1 and 2 are rather different. Based on theoretical calculations and experimental results, we propose that some of the stable conformers might be connected with either a charge-transfer complex or mesomeric interactions in the ground state. Upon changing the electronic nature of the oxo-pentadienyl acceptor moiety, e.g. protonation, chemical or biochemical reaction, the charge-transfer absorption disappears, which leads to a dramatic increase in the fluorescence quantum yield.
Effect of baseline plasma fatty acids on eicosapentaenoic acid levels in individuals supplemented with alpha-linolenic acid.

PubMed

DeFilippis, Andrew P; Harper, Charles R; Cotsonis, George A; Jacobson, Terry A

2009-01-01

We previously reported a >50% increase in mean plasma eicosapentaenoic acid levels in a general medicine clinic population after supplementation with alpha-linolenic acid. In the current analysis, we evaluate the variability of changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid and evaluated the impact of baseline plasma fatty acids levels on changes in eicosapentaenoic acid levels in these individuals. Changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid ranged from a 55% decrease to a 967% increase. Baseline plasma fatty acids had no statistically significant effect on changes in eicosapentaenoic levels acid after alpha-linolenic acid supplementation. Changes in eicosapentaenoic acid levels varied considerably in a general internal medicine clinic population supplemented with alpha-linolenic acid. Factors that may impact changes in plasma eicosapentaenoic acid levels after alpha-linolenic acid supplementation warrant further study.
Evidence for Arginine as the Endogenous Precursor of Necines in Heliotropium1

PubMed Central

Birecka, Helena; Birecki, Mieczyslaw; Frohlich, M. W.

1987-01-01

In pyrrolizidine alkaloid-bearing Heliotropium angiospermum and H. indicum shoots exposed, in the light, to 14C-labeled CO2 for 44 hours, the incorporation of 14C into 1,2-epoxy-1-hydroxymethylpyrrolizidine and retronecine amounted to 0.23 and 0.15%, respectively, of the total carbon assimilated. Treatment of the shoots with α-dl-difluoromethylornithine, the specific ornithine decarboxylase inhibitor, at 1 to 2 millimolar had no effect on 14C incorporation into the necines. In contrast, α-dl-difluoromethylarginine, the specific arginine decarboxylase inhibitor, prevented the incorporation of 14C into the necines of both species; the inhibitor did not affect the absolute incorporation of 14C from exogenous [1,4-14C] putrescine in either species. Thus, arginine is the only apparent endogenous precursor of the putrescine channeled into pyrrolizidines, at least in these two Heliotropium species that exhibited a relatively much higher in vitro activity of arginine decarboxylase than of ornithine decarboxylase. However, within 28 hours after administration, not only exogenous l-[5-14C]arginine, but also exogenous l-[5-14C]ornithine exhibited significant incorporation of their label into the necines, incorporation that could be partially prevented by both inhibitors. Neither inhibitor affected the rates of 14C-labeled CO2 assimilation, transformation of labeled assimilates into ethanol-insoluble compounds, or the very high degree of conversion of the introduced amino acids into other compounds. Methodology related to alkaloid biosynthetic studies is discussed. PMID:16665402
Orotic aciduria and uridine monophosphate synthase: a reappraisal.

PubMed

Bailey, C J

2009-12-01

Three subtypes of hereditary orotic aciduria are described in the literature, all related to deficiencies in uridine monophosphate synthase, the multifunctional enzyme that contains both orotate: pyrophosphoryl transferase and orotidine monophosphate decarboxylase activities. The type of enzyme defect present in the subtypes has been re-examined by steady-state modelling of the relative outputs of the three enzymic products, uridine monophosphate, urinary orotic acid and urinary orotidine. It is shown that the ratio of urinary outputs of orotidine to orotate provides a means of testing for particular forms of enzyme defect. It is confirmed that the type I defect is caused by loss of uridine monophosphate synthase activity. Cells and tissue of type I cases have a residual amount of activity that is qualitatively unchanged: the relative rates of the transferase and decarboxylase do not differ from those of wild-type enzyme. The single claimed case of type II, thought to be due to specific inactivation of orotidine monophosphate decarboxylase, is shown to have a product spectrum inconsistent with that claim. It is proposed that this type II form does not differ sufficiently to be accepted as separate from type I. The third subtype, hereditary orotic aciduria without megaloblastic anaemia, occurs in two cases. It has the product spectrum expected of a defect in orotidine monophosphate decarboxylase. This form is the only one that appears to have a qualitatively different uridine monophosphate synthase. The possibility that orotidine monophosphate may control flux through the pyrimidine biosynthesis pathway in hereditary orotic aciduria is discussed.
Pantothenic acid deficiency may increase the urinary excretion of 2-oxo acids and nicotinamide catabolites in rats.

PubMed

Shibata, Katsumi; Inomoto, Kasumi; Nakata, Chifumi; Fukuwatari, Tsutomu

2013-01-01

Pantothenic acid (PaA) is involved in the metabolism of amino acids as well as fatty acid. We investigated the systemic metabolism of amino acids in PaA-deficient rats. For this purpose, urine samples were collected and 2-oxo acids and L-tryptophan (L-Trp) and its metabolites including nicotinamide were measured. Group 1 was freely fed a conventional chemically-defined complete diet and used as an ad lib-fed control, which group was used for showing reference values. Group 2 was freely fed the complete diet without PaA (PaA-free diet) and used as a PaA-deficient group. Group 3 was fed the complete diet, but the daily food amount was equal to the amount of the PaA-deficient group and used as a pair-fed control group. All rats were orally administered 100 mg of L-Trp/kg body weight at 09:00 on day 34 of the experiment and the following 24-h urine samples were collected. The urinary excretion of the sum of pyruvic acid and oxaloacetic acid was higher in rats fed the PaA-free diets than in the rats fed pair-fed the complete diet. PaA deficiency elicited the increased urinary excretion of anthranilic acid and kynurenic acid, while the urinary excretion of xanthurenic acid decreased. The urinary excretion of L-Trp itself, 3-hydroxyanthranilic acid, and quinolinic acid revealed no differences between the rats fed the PaA-free and pair-fed the complete diets. PaA deficiency elicited the increased excretion of N(1)-methylnicotinamide, N(1)-methyl-2-pyridone-5-carboxamide, and N(1)-methyl-4-pyridone-3-carboxamide. These findings suggest that PaA deficiency disturbs the amino acid catabolism.
Comparative Proteome Analysis of Wheat Flag Leaves and Developing Grains Under Water Deficit

PubMed Central

Deng, Xiong; Liu, Yue; Xu, Xuexin; Liu, Dongmiao; Zhu, Genrui; Yan, Xing; Wang, Zhimin; Yan, Yueming

2018-01-01

In this study, we performed the first comparative proteomic analysis of wheat flag leaves and developing grains in response to drought stress. Drought stress caused a significant decrease in several important physiological and biochemical parameters and grain yield traits, particularly those related to photosynthesis and starch biosynthesis. In contrast, some key indicators related to drought stress were significantly increased, including malondialdehyde, soluble sugar, proline, glycine betaine, abscisic acid content, and peroxidase activity. Two-dimensional difference gel electrophoresis (2D-DIGE) identified 87 and 132 differentially accumulated protein (DAP) spots representing 66 and 105 unique proteins following exposure to drought stress in flag leaves and developing grains, respectively. The proteomes of the two organs varied markedly, and most DAPS were related to the oxidative stress response, photosynthesis and energy metabolism, and starch biosynthesis. In particular, DAPs in flag leaves mainly participated in photosynthesis while those in developing grains were primarily involved in carbon metabolism and the drought stress response. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) further validated some key DAPs such as rubisco large subunit (RBSCL), ADP glucose pyrophosphorylase (AGPase), chaperonin 60 subunit alpha (CPN-60 alpha) and oxalate oxidase 2 (OxO 2). The potential functions of the identified DAPs revealed that a complex network synergistically regulates drought resistance during grain development. Our results from proteome perspective provide new insight into the molecular regulatory mechanisms used by different wheat organs to respond to drought stress. PMID:29692790
Investigation of neuronal auto-antibodies in systemic lupus erythematosus patients with epilepsy.

PubMed

Karaaslan, Zerrin; Ekizoğlu, Esme; Tektürk, Pınar; Erdağ, Ece; Tüzün, Erdem; Bebek, Nerses; Gürses, Candan; Baykan, Betül

2017-01-01

Epilepsy is an important feature for neuropsychiatric involvement in systemic lupus erythematosus (SLE) with unknown mechanism. Our aim was to investigate the presence of neuronal auto-antibodies (NAbs) in neuropsychiatric SLE (NPSLE). Eighteen SLE patients (17 females, 1 male) experiencing recurrent seizures were enrolled to this study. Their clinical characteristics, EEG and MRI findings and follow-up information were evaluated from their files. Antibodies against voltage-gated potassium channel (VGKC)-complex antigens, contactin-associated protein-like 2 (CASPR-2), leucine-rich, glioma inactivated 1 (LGI1), glutamic acid decarboxylase (GAD), N-methyl-d-aspartate receptor (NMDA-R), alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor (AMPA-R) and type B gamma aminobutyric acid receptors (GABA B -R) were screened in the sera of these patients. Moreover, indirect immunohistochemistry and immunocytochemistry tests were performed to reveal neuropil antibodies. Six out of 18 patients (33.3%) had various forms of NAbs. Among them, one patient had antibodies against GAD, one patient with hippocampal sclerosis on MRI was CASPR-2 antibody positive, whereas the remaining four patients showed hippocampal neuropil staining. We could not find a significant difference between seropositive and seronegative groups, regarding the clinical characteristics, EEG and MRI findings. This study is the first to show hippocampal neuronal staining (4/18) reflecting antibodies against unknown neuronal cell surface antigens in SLE patients with epilepsy, besides the rare occurrence of GAD and CASPR2 antibodies. Further prospective studies are needed to search for new NAbs and uncover their pathogenic role in SLE associated with epilepsy. Copyright © 2016 Elsevier B.V. All rights reserved.
Increased expression of glutamic acid decarboxylase mRNA in rat substantia nigra after an ibotenic acid lesion in the caudate-putamen.

PubMed

Lindefors, N; Brené, S; Persson, H

1990-04-01

In situ hybridization histochemistry and RNA blots were used to study expression of glutamic acid decarboxylase (GAD) mRNA in rat caudate-nucleus and substantia nigra. In situ hybridization combined with computerized image analysis revealed that in the intact substantia nigra reticulata the cross-section area of GAD mRNA positive neurons were 25% larger in the dorsolateral part as compared with the ventromedial part. A unilateral ibotenic acid injection in caudate-putamen lesioned neurons, some of which project to the ipsilateral substantia nigra. An increased level of GAD mRNA was observed in substantia nigra ipsilateral to the lesion. Computerized image analysis of sections from in situ hybridization revealed an increase in the number of silver grains over GAD mRNA positive neurons in the dorsolateral substantia nigra reticulata ipsilateral to the lesion. However, no change was observed in the ventromedial part suggesting that GAD mRNA expression in this part of the nigra is less sensitive to inhibition by caudate-putamen afferents. In agreement with in situ experiments, RNA blots showed a 2-fold increased level of GAD mRNA in substantia nigra ipsilateral to the lesion. The increased GAD mRNA expression in the deafferented substantia nigra suggests a disinhibition of nigral GABA neurons, resulting in an increased utilization of GABA in these substantia nigra neurons.
Efficient Production of γ-GABA Using Recombinant E. coli Expressing Glutamate Decarboxylase (GAD) Derived from Eukaryote Saccharomyces cerevisiae.

PubMed

Xiong, Qiang; Xu, Zheng; Xu, Lu; Yao, Zhong; Li, Sha; Xu, Hong

2017-12-01

γ-Aminobutyric acid (γ-GABA) is a non-proteinogenic amino acid, which acts as a major regulator in the central nervous system. Glutamate decarboxylase (namely GAD, EC 4.1.1.15) is known to be an ideal enzyme for γ-GABA production using L-glutamic acid as substrate. In this study, we cloned and expressed GAD gene from eukaryote Saccharomyces cerevisiae (ScGAD) in E. coli BL21(DE3). This enzyme was further purified and its optimal reaction temperature and pH were 37 °C and pH 4.2, respectively. The cofactor of ScGAD was verified to be either pyridoxal 5'-phosphate (PLP) or pyridoxal hydrochloride. The optimal concentration of either cofactor was 50 mg/L. The optimal medium for E. coli-ScGAD cultivation and expression were 10 g/L lactose, 5 g/L glycerol, 20 g/L yeast extract, and 10 g/L sodium chloride, resulting in an activity of 55 U/mL medium, three times higher than that of using Luria-Bertani (LB) medium. The maximal concentration of γ-GABA was 245 g/L whereas L-glutamic acid was near completely converted. These findings provided us a good example for bio-production of γ-GABA using recombinant E. coli expressing a GAD enzyme derived from eukaryote.
Assembly of lipase and P450 fatty acid decarboxylase to constitute a novel biosynthetic pathway for production of 1-alkenes from renewable triacylglycerols and oils.

PubMed

Yan, Jinyong; Liu, Yi; Wang, Cong; Han, Bingnan; Li, Shengying

2015-01-01

Biogenic hydrocarbons (biohydrocarbons) are broadly accepted to be the ideal 'drop-in' biofuel alternative to petroleum-based fuels due to their highly similar chemical composition and physical characteristics. The biological production of aliphatic hydrocarbons is largely dependent on engineering of the complicated enzymatic network surrounding fatty acid biosynthesis. In this work, we developed a novel system for bioproduction of terminal fatty alkenes (1-alkenes) from renewable and low-cost triacylglycerols (TAGs) based on the lipase hydrolysis coupled to the P450 catalyzed decarboxylation. This artificial biosynthetic pathway was constituted using both cell-free systems including purified enzymes or cell-free extracts, and cell-based systems including mixed resting cells or growing cells. The issues of high cost of fatty acid feedstock and complicated biosynthesis network were addressed by replacement of the de novo biosynthesized fatty acids with the fed cheap TAGs. This recombinant tandem enzymatic pathway consisting of the Thermomyces lanuginosus lipase (Tll) and the P450 fatty acid decarboxylase OleTJE resulted in the production of 1-alkenes from purified TAGs or natural oils with 6.7 to 46.0% yields. Since this novel hydrocarbon-producing pathway only requires two catalytically efficient enzymatic steps, it may hold great potential for industrial application by fulfilling the large-scale and cost-effective conversion of renewable TAGs into biohydrocarbons. This work highlights the power of designing and implementing an artificial pathway for production of advanced biofuels.
Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production

PubMed Central

Tajabadi, Naser; Baradaran, Ali; Ebrahimpour, Afshin; Rahim, Raha A; Bakar, Fatimah A; Manap, Mohd Yazid A; Mohammed, Abdulkarim S; Saari, Nazamid

2015-01-01

Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products. PMID:25757029
Dissecting the total transition state stabilization provided by amino acid side chains at orotidine 5'-monophosphate decarboxylase: a two-part substrate approach.

PubMed

Barnett, Shonoi A; Amyes, Tina L; Wood, Bryant M; Gerlt, John A; Richard, John P

2008-07-29

Kinetic analysis of decarboxylation catalyzed by S154A, Q215A, and S154A/Q215A mutant yeast orotidine 5'-monophosphate decarboxylases with orotidine 5'-monophosphate (OMP) and with a truncated nucleoside substrate (EO) activated by phosphite dianion shows (1) the side chain of Ser-154 stabilizes the transition state through interactions with the pyrimidine rings of OMP or EO, (2) the side chain of Gln-215 interacts with the phosphodianion group of OMP or with phosphite dianion, and (3) the interloop hydrogen bond between the side chains of Ser-154 and Gln-215 orients the amide side chain of Gln-215 to interact with the phosphodianion group of OMP or with phosphite dianion.

Single nucleotide polymorphisms of PAD1 and FDC1 show a positive relationship with ferulic acid decarboxylation ability among industrial yeasts used in alcoholic beverage production.

PubMed

Mukai, Nobuhiko; Masaki, Kazuo; Fujii, Tsutomu; Iefuji, Haruyuki

2014-07-01

Among industrial yeasts used for alcoholic beverage production, most wine and weizen beer yeasts decarboxylate ferulic acid to 4-vinylguaiacol, which has a smoke-like flavor, whereas sake, shochu, top-fermenting, and bottom-fermenting yeast strains lack this ability. However, the factors underlying this difference among industrial yeasts are not clear. We previously confirmed that both PAD1 (phenylacrylic acid decarboxylase gene, YDR538W) and FDC1 (ferulic acid decarboxylase gene, YDR539W) are essential for the decarboxylation of phenylacrylic acids in Saccharomyces cerevisiae. In the present study, single nucleotide polymorphisms (SNPs) of PAD1 and FDC1 in sake, shochu, wine, weizen, top-fermenting, bottom-fermenting, and laboratory yeast strains were examined to clarify the differences in ferulic acid decarboxylation ability between these types of yeast. For PAD1, a nonsense mutation was observed in the gene sequence of standard top-fermenting yeast. Gene sequence analysis of FDC1 revealed that sake, shochu, and standard top-fermenting yeasts contained a nonsense mutation, whereas a frameshift mutation was identified in the FDC1 gene of bottom-fermenting yeast. No nonsense or frameshift mutations were detected in laboratory, wine, or weizen beer yeast strains. When FDC1 was introduced into sake and shochu yeast strains, the transformants exhibited ferulic acid decarboxylation activity. Our findings indicate that a positive relationship exists between SNPs in PAD1 and FDC1 genes and the ferulic acid decarboxylation ability of industrial yeast strains. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
Mode of alpha-amylase production by the shochu koji mold Aspergillus kawachii.

PubMed

Nagamine, Kazuki; Murashima, Kenji; Kato, Taku; Shimoi, Hitoshi; Ito, Kiyoshi

2003-10-01

Aspergillus kawachii produces two kinds of alpha-amylase, one is an acid-unstable alpha-amylase and the other is an acid-stable alpha-amylase. Because the quality of the shochu depends strongly on the activities of the alpha-amylases, the culture conditions under which these alpha-amylases are produced were examined. In liquid culture, acid-unstable alpha-amylase was produced abundantly, but, acid-stable alpha-amylase was not produced. The acid-unstable alpha-amylase was produced significantly when glycerol or glucose was used as a carbon source, similarly to the use of inducers such as starch or maltose. In liquid culture, A. kawachii assimilated starch at pH 3.0, but no alpha-amylase activity was recognized in the medium. Instead, the alpha-amylase was found to be trapped in the cell wall. The trapped form was identified as acid-unstable alpha-amylase. Usually, acid-unstable alpha-amylase is unstable at pH 3.0, so its stability appeared to be due to its immobilization in the cell wall. In solid-state culture, both kinds of alpha-amylase were produced. The production of acid-stable alpha-amylase seems to be solid-state culture-specific and was affected by the moisture content in the solid medium.
Inhibition of the synthesis of polyamines and DNA in activated lymphocytes by a combination of alpha-methylornithine and methylglyoxal bis(guanylhydrazone).

PubMed

Morris, D R; Jorstad, C M; Seyfried, C E

1977-09-01

The cancer chemotherapeutic drug, methylglyoxal bis(guanylhydrazone), inhibits the synthesis of spermidine and spermine, but allows continued putrescine production in small lymphocytes stimulated by concanavalin A. DNA replication in these cells is inhibited 50% while the synthesis of protein and RNA continues normally. When excess putrescine accumulation in the presence of methylglyoxal bis(guanylhydrazone) was inhibited with alpha-methylornithine, a competitive inhibitor of ornithine decarboxylase, the inhibition of DNA replication was accentuated, with still no effect on protein or RNA synthesis. No inhibition of DNA synthesis by the combination of alpha-methylornithine and methylglyoxal bis(guanylhydrazone) was observed when the inhibitors were added after accumulation of cellular polyamines. In addition, inhibition was reversed by exogenous putrescine, spermidine, or spermine. We conclude that putrescine can fulfill in part the role normally played by spermidine and spermine in DNA replication, and that blocking putrescine synthesis in the presence of methylglyoxal bis(guanylhydrazone) amplifies the polyamine requirement. The implications of this with regard to polyamine synthesis as a site of chemotherapy are discussed.
New and highly sensitive assay for L-5-hydroxytryptophan decarboxylase activity by high-performance liquid chromatography-voltammetry.

PubMed

Rahman, M K; Nagatsu, T; Kato, T

1980-12-12

This paper describes a new, inexpensive and highly sensitive assay for aromatic L-amino acid decarboxylase (AADC) activity, using L-5-hydroxytryptophan (L-5-HTP) as substrate, in rat and human brains and serum by high-performance liquid chromatography (HPLC) with voltammetric detection. L-5-HTP was used as substrate and D-5-HTP for the blank. After isolating serotonin (5-HT) formed enzymatically from L-5-HTP on a small Amberlite CG-50 column, the 5-HT was eluted with hydrochloric acid and assayed by HPLC with a voltammetric detector. N-Methyldopamine was added to each incubation mixture as an internal standard. This method is sensitive enough to measure 5-HT, formed by the enzyme, 100 fmol to 140 pmol or more. An advantage of this method is that one can incubate the enzyme for longer time (up to 150 min), as compared with AADC assay using L-DOPA as substrate, resulting in a very high sensitivity. By using this new method, AADC activity was discovered in rat serum.
Camphor revisited: involvement of a unique monooxygenase in metabolism of 2-oxo-delta 3-4,5,5-trimethylcyclopentenylacetic acid by Pseudomonas putida.

PubMed Central

Ougham, H J; Taylor, D G; Trudgill, P W

1983-01-01

Previously, Pseudomonas putida was shown to degrade (+)-camphor, and cleavage of the first ring of the bicyclic structure involved two monooxygenases (a hydroxylase and a ring oxygen-inserting enzyme), a dehydrogenase, and spontaneous cleavage of an unstable oxygenation product (lactone). Cleavage of the second ring was not demonstrated but was assumed also to occur by ring oxygen insertion, since the predicted oxygenation product was extracted from whole-cell incubation systems. Our investigation established that metabolism of the first ring cleavage intermediate, 2-oxo-delta 3-4,5,5-trimethylcyclopentenylacetic acid, occurred through the sequential action of two inducible enzymes, a coenzyme A ester synthetase and an oxygenase. The oxygenase was purified to homogeneity and had a molecular weight of 106,000. This enzyme carried a single molecule of flavin adenine dinucleotide and consisted of two identical subunits. Iron was not present at a significant level. The oxygenase was specific for NADPH as the electron donor and absolutely specific for the coenzyme A ester of 2-oxo-delta 3-4,5,5-trimethylcyclopentenylacetic acid as the substrate. The reaction stoichiometry was compatible with this enzyme being a monooxygenase, and a mass spectral analysis of the methyl ester of the product confirmed the insertion of a single oxygen atom. The enzyme appeared to be analogous to, although distinct from. 2,5-diketocamphane 1,2-monooxygenase in catalyzing a "biological Baeyer-Villiger" reaction with the formation of a lactone. Structural analogy suggested that this lactone, like the first, was also unstable and susceptible to spontaneous ring opening, although this was not experimentally established. Images PMID:6848481
Camphor revisited: involvement of a unique monooxygenase in metabolism of 2-oxo-delta 3-4,5,5-trimethylcyclopentenylacetic acid by Pseudomonas putida.

PubMed

Ougham, H J; Taylor, D G; Trudgill, P W

1983-01-01

Previously, Pseudomonas putida was shown to degrade (+)-camphor, and cleavage of the first ring of the bicyclic structure involved two monooxygenases (a hydroxylase and a ring oxygen-inserting enzyme), a dehydrogenase, and spontaneous cleavage of an unstable oxygenation product (lactone). Cleavage of the second ring was not demonstrated but was assumed also to occur by ring oxygen insertion, since the predicted oxygenation product was extracted from whole-cell incubation systems. Our investigation established that metabolism of the first ring cleavage intermediate, 2-oxo-delta 3-4,5,5-trimethylcyclopentenylacetic acid, occurred through the sequential action of two inducible enzymes, a coenzyme A ester synthetase and an oxygenase. The oxygenase was purified to homogeneity and had a molecular weight of 106,000. This enzyme carried a single molecule of flavin adenine dinucleotide and consisted of two identical subunits. Iron was not present at a significant level. The oxygenase was specific for NADPH as the electron donor and absolutely specific for the coenzyme A ester of 2-oxo-delta 3-4,5,5-trimethylcyclopentenylacetic acid as the substrate. The reaction stoichiometry was compatible with this enzyme being a monooxygenase, and a mass spectral analysis of the methyl ester of the product confirmed the insertion of a single oxygen atom. The enzyme appeared to be analogous to, although distinct from. 2,5-diketocamphane 1,2-monooxygenase in catalyzing a "biological Baeyer-Villiger" reaction with the formation of a lactone. Structural analogy suggested that this lactone, like the first, was also unstable and susceptible to spontaneous ring opening, although this was not experimentally established.
Synthesis, crystal structure, DFT studies, acid dissociation constant, and antimicrobial activity of methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate

NASA Astrophysics Data System (ADS)

Nural, Yahya; Gemili, Muge; Seferoglu, Nurgul; Sahin, Ertan; Ulger, Mahmut; Sari, Hayati

2018-05-01

A novel bicyclic thiohydantoin fused to pyrrolidine compound, methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate, was synthesized by the cyclization reaction of dimethyl 5,5-diphenylpyrrolidine-2,4-dicarboxylate and 4-chlorophenyl isothiocyanate in the presence of 4-(dimethylamino)pyridine to form methyl 2-(4-chlorophenyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate with concomitant addition reaction of the 4-chlorophenyl isothiocyanate in 79% yield. The structural characterization was performed by NMR, FT-IR, MS and HRMS techniques, and the stereochemistry of the compound was determined by single crystal X-ray diffraction study. In addition, the molecular structure and 1H and 13C NMR chemical shifts of the compound were obtained with the density functional theory and Hartree-Fock calculations. Acid dissociation constants of the compound were determined using potentiometric titration method in 25% (v/v) dimethyl sulfoxide-water hydroorganic solvent at 25 ± 0.1 °C, at an ionic background of 0.1 mol/L of NaCl using the HYPERQUAD computer program. Four acid dissociation constants were obtained for the compound, and we suggest that these acid dissociation constants are related to the NH, for two groups of enthiols and enol groups. Antimicrobial activity study was performed against S. aureus, B. subtilis, A. hydrophila, E. coli and A. baumannii as bacterial standard strains, and against M. tuberculosis H37Rv as mycobacterial strain. The compound exhibited antibacterial activity in the range of 31.25-62.5 μg/mL, and antimycobacterial activity with a MIC value of 40 μg/mL against the indicated strains.
Taste-Active Maillard Reaction Products in Roasted Garlic (Allium sativum).

PubMed

Wakamatsu, Junichiro; Stark, Timo D; Hofmann, Thomas

2016-07-27

In order to gain first insight into candidate Maillard reaction products formed upon thermal processing of garlic, mixtures of glucose and S-allyl-l-cysteine, the major sulfur-containing amino acid in garlic, were low-moisture heated, and nine major reaction products were isolated. LC-TOF-MS, 1D/2D NMR, and CD spectroscopy led to their identification as acortatarin A (1), pollenopyrroside A (2), epi-acortatarin A (3), xylapyrroside A (4), 5-hydroxymethyl-1-[(5-hydroxymethyl-2-furanyl)methyl]-1H-pyrrole-2-carbalde-hyde (5), 3-(allylthio)-2-(2-formyl-5-hydroxymethyl-1H-pyrrol-1-yl)propanoic acid (6), (4S)-4-(allylthiomethyl)-3,4-dihydro-3-oxo-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (7), (2R)-3-(allylthio)-2-[(4R)-4-(allylthiomethyl)-6-formyl-3-oxo-3,4-dihydropyrrolo-[1,2-a]pyrazin-2(1H)-yl]propanoic acid (8), and (2R)-3-(allylthio)-2-((4S)-4-(allylthiomethyl)-6-formyl-3-oxo-3,4-dihydropyrrolo-[1,2-a]pyrazin-2(1H)-yl)propanoic acid (9). Among the Maillard reaction products identified, compounds 5-9 have not previously been published. The thermal generation of the literature known spiroalkaloids 1-4 is reported for the first time. Sensory analysis revealed a bitter taste with thresholds between 0.5 and 785 μmol/kg for 1-5 and 7-9. Compound 6 did not show any intrinsic taste (water) but exhibited a strong mouthfullness (kokumi) enhancing activity above 186 μmol/kg. LC-MS/MS analysis showed 1-9 to be generated upon pan-frying of garlic with the highest concentration of 793.7 μmol/kg found for 6, thus exceeding its kokumi threshold by a factor of 4 and giving evidence for its potential taste modulation activity in processed garlic preparations.
Disruption of pknG enhances production of gamma-aminobutyric acid by Corynebacterium glutamicum expressing glutamate decarboxylase.

PubMed

Okai, Naoko; Takahashi, Chihiro; Hatada, Kazuki; Ogino, Chiaki; Kondo, Akihiko

2014-01-01

Gamma-aminobutyric acid (GABA), a building block of the biodegradable plastic polyamide 4, is synthesized from glucose by Corynebacterium glutamicum that expresses Escherichia coli glutamate decarboxylase (GAD) B encoded by gadB. This strain was engineered to produce GABA more efficiently from biomass-derived sugars. To enhance GABA production further by increasing the intracellular concentration of its precursor glutamate, we focused on engineering pknG (encoding serine/threonine protein kinase G), which controls the activity of 2-oxoglutarate dehydrogenase (Odh) in the tricarboxylic acid cycle branch point leading to glutamate synthesis. We succeeded in expressing GadB in a C. glutamicum strain harboring a deletion of pknG. C. glutamicum strains GAD and GAD ∆pknG were cultured in GP2 medium containing 100 g L(-1) glucose and 0.1 mM pyridoxal 5'-phosphate. Strain GAD∆pknG produced 31.1 ± 0.41 g L(-1) (0.259 g L(-1) h(-1)) of GABA in 120 hours, representing a 2.29-fold higher level compared with GAD. The production yield of GABA from glucose by GAD∆pknG reached 0.893 mol mol(-1).
Systematic study of association of four GABAergic genes: glutamic acid decarboxylase 1 gene, glutamic acid decarboxylase 2 gene, GABA(B) receptor 1 gene and GABA(A) receptor subunit beta2 gene, with schizophrenia using a universal DNA microarray.

PubMed

Zhao, Xu; Qin, Shengying; Shi, Yongyong; Zhang, Aiping; Zhang, Jing; Bian, Li; Wan, Chunling; Feng, Guoyin; Gu, Niufan; Zhang, Guangqi; He, Guang; He, Lin

2007-07-01

Several studies have suggested the dysfunction of the GABAergic system as a risk factor in the pathogenesis of schizophrenia. In the present study, case-control association analysis was conducted in four GABAergic genes: two glutamic acid decarboxylase genes (GAD1 and GAD2), a GABA(A) receptor subunit beta2 gene (GABRB2) and a GABA(B) receptor 1 gene (GABBR1). Using a universal DNA microarray procedure we genotyped a total of 20 SNPs on the above four genes in a study involving 292 patients and 286 controls of Chinese descent. Statistically significant differences were observed in the allelic frequencies of the rs187269C/T polymorphism in the GABRB2 gene (P=0.0450, chi(2)=12.40, OR=1.65) and the -292A/C polymorphism in the GAD1 gene (P=0.0450, chi(2)=14.64 OR=1.77). In addition, using an electrophoretic mobility shift assay (EMSA), we discovered differences in the U251 nuclear protein binding to oligonucleotides representing the -292 SNP on the GAD1 gene, which suggests that the -292C allele has reduced transcription factor binding efficiency compared with the 292A allele. Using the multifactor-dimensionality reduction method (MDR), we found that the interactions among the rs187269C/T polymorphism in the GABRB2 gene, the -243A/G polymorphism in the GAD2 gene and the 27379C/T and 661C/T polymorphisms in the GAD1 gene revealed a significant association with schizophrenia (P<0.001). These findings suggest that the GABRB2 and GAD1 genes alone and the combined effects of the polymorphisms in the four GABAergic system genes may confer susceptibility to the development of schizophrenia in the Chinese population.
Cortical Gene Expression After a Conditional Knockout of 67 kDa Glutamic Acid Decarboxylase in Parvalbumin Neurons.

PubMed

Georgiev, Danko; Yoshihara, Toru; Kawabata, Rika; Matsubara, Takurou; Tsubomoto, Makoto; Minabe, Yoshio; Lewis, David A; Hashimoto, Takanori

2016-07-01

In the cortex of subjects with schizophrenia, expression of glutamic acid decarboxylase 67 (GAD67), the enzyme primarily responsible for cortical GABA synthesis, is reduced in the subset of GABA neurons that express parvalbumin (PV). This GAD67 deficit is accompanied by lower cortical levels of other GABA-associated transcripts, including GABA transporter-1, PV, brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B, somatostatin, GABAA receptor α1 subunit, and KCNS3 potassium channel subunit mRNAs. In contrast, messenger RNA (mRNA) levels for glutamic acid decarboxylase 65 (GAD65), another enzyme for GABA synthesis, are not altered. We tested the hypothesis that this pattern of GABA-associated transcript levels is secondary to the GAD67 deficit in PV neurons by analyzing cortical levels of these GABA-associated mRNAs in mice with a PV neuron-specific GAD67 knockout. Using in situ hybridization, we found that none of the examined GABA-associated transcripts had lower cortical expression in the knockout mice. In contrast, PV, BDNF, KCNS3, and GAD65 mRNA levels were higher in the homozygous mice. In addition, our behavioral test battery failed to detect a change in sensorimotor gating or working memory, although the homozygous mice exhibited increased spontaneous activities. These findings suggest that reduced GAD67 expression in PV neurons is not an upstream cause of the lower levels of GABA-associated transcripts, or of the characteristic behaviors, in schizophrenia. In PV neuron-specific GAD67 knockout mice, increased levels of PV, BDNF, and KCNS3 mRNAs might be the consequence of increased neuronal activity secondary to lower GABA synthesis, whereas increased GAD65 mRNA might represent a compensatory response to increase GABA synthesis. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Effect of friction on oxidative graphite intercalation and high-quality graphene formation.

PubMed

Seiler, Steffen; Halbig, Christian E; Grote, Fabian; Rietsch, Philipp; Börrnert, Felix; Kaiser, Ute; Meyer, Bernd; Eigler, Siegfried

2018-02-26

Oxidative wet-chemical delamination of graphene from graphite is expected to become a scalable production method. However, the formation process of the intermediate stage-1 graphite sulfate by sulfuric acid intercalation and its subsequent oxidation are poorly understood and lattice defect formation must be avoided. Here, we demonstrate film formation of micrometer-sized graphene flakes with lattice defects down to 0.02% and visualize the carbon lattice by transmission electron microscopy at atomic resolution. Interestingly, we find that only well-ordered, highly crystalline graphite delaminates into oxo-functionalized graphene, whereas other graphite grades do not form a proper stage-1 intercalate and revert back to graphite upon hydrolysis. Ab initio molecular dynamics simulations show that ideal stacking and electronic oxidation of the graphite layers significantly reduce the friction of the moving sulfuric acid molecules, thereby facilitating intercalation. Furthermore, the evaluation of the stability of oxo-species in graphite sulfate supports an oxidation mechanism that obviates intercalation of the oxidant.
Characterization of particulate products for aging of ethylbenzene secondary organic aerosol in the presence of ammonium sulfate seed aerosol.

PubMed

Huang, Mingqiang; Zhang, Jiahui; Cai, Shunyou; Liao, Yingmin; Zhao, Weixiong; Hu, Changjin; Gu, Xuejun; Fang, Li; Zhang, Weijun

2016-09-01

Aging of secondary organic aerosol (SOA) particles formed from OH- initiated oxidation of ethylbenzene in the presence of high mass (100-300μg/m(3)) concentrations of (NH4)2SO4 seed aerosol was investigated in a home-made smog chamber in this study. The chemical composition of aged ethylbenzene SOA particles was measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) coupled with a Fuzzy C-Means (FCM) clustering algorithm. Experimental results showed that nitrophenol, ethyl-nitrophenol, 2,4-dinitrophenol, methyl glyoxylic acid, 5-ethyl-6-oxo-2,4-hexadienoic acid, 2-ethyl-2,4-hexadiendioic acid, 2,3-dihydroxy-5-ethyl-6-oxo-4-hexenoic acid, 1H-imidazole, hydrated N-glyoxal substituted 1H-imidazole, hydrated glyoxal dimer substituted imidazole, 1H-imidazole-2-carbaldehyde, N-glyoxal substituted hydrated 1H-imidazole-2-carbaldehyde and high-molecular-weight (HMW) components were the predominant products in the aged particles. Compared to the previous aromatic SOA aging studies, imidazole compounds, which can absorb solar radiation effectively, were newly detected in aged ethylbenzene SOA in the presence of high concentrations of (NH4)2SO4 seed aerosol. These findings provide new information for discussing aromatic SOA aging mechanisms. Copyright © 2016. Published by Elsevier B.V.
Simultaneous quantification of various retinoids by high performance liquid chromatography: its relevance to alcohol research.

PubMed

Yokoyama, H; Matsumoto, M; Shiraishi, H; Ishii, H

2000-04-01

We established a high performance liquid chromatography system that allowed simultaneous quantification of various retinoids. We applied the retinoids to a high performance liquid chromatography system with a silica gel absorption column. Samples were separated by the system with a binary multistep gradient with two kinds of solvent that contained n-Hexan, 2-propanol, and glacial acetic acid in different ratios. Each retinoid was detected at a wavelength of 350 nm. This condition allowed separation of 13-cis-retinoic acid, 9-cis-retinoic acid, all-trans-retinoic acid, 13-cis-retinol, all-trans-retinol, all-trans-4-oxo-retinoic acid, and 13-cis-4-oxo-retinoic acid as distinct single peaks. Each retinoid was also analyzed separately and its retention time determined. To ascertain the reliability of this system for retinoid quantification, retinoids at various concentrations were applied to the system. We observed the linearities between the concentration and area under the curve of the peak for each retinoid by linear least-squares regression analysis up to 2.5 ng/ml for all retinoic acids and up to 5 ng/ml for all retinols. There was no significant scattering in tests of within-day reproducibility or day-to-day reproducibility. Using this system, we examined effects of light exposure on isomerization of retinoids. When retinoids were exposed to room light for 2 hr, the amounts of all but 13-cis-retinol changed significantly. In particular, the amounts of all-trans-retinoic acid and 9-cis-retinoic acid were reduced by 40% and 60%, respectively. The HPLC system established in this study should be useful for studying the oxidation pathway of retinol to retinoic acid. A light-shielded condition is required when particular retinoic acids are analyzed.
7alpha- and 12alpha-Hydroxysteroid dehydrogenases from Acinetobacter calcoaceticus lwoffii: a new integrated chemo-enzymatic route to ursodeoxycholic acid.

PubMed

Giovannini, Pier Paolo; Grandini, Alessandro; Perrone, Daniela; Pedrini, Paola; Fantin, Giancarlo; Fogagnolo, Marco

2008-12-22

We report the very efficient biotransformation of cholic acid to 7-keto- and 7,12-diketocholic acids with Acinetobacter calcoaceticus lwoffii. The enzymes responsible of the biotransformation (i.e. 7alpha- and 12alpha-hydroxysteroid dehydrogenases) are partially purified and employed in a new chemo-enzymatic synthesis of ursodeoxycholic acid starting from cholic acid. The first step is the 12alpha-HSDH-mediated total oxidation of sodium cholate followed by the Wolf-Kishner reduction of the carbonyl group to chenodeoxycholic acid. This acid is then quantitatively oxidized with 7alpha-HSDH to 7-ketochenodeoxycholic acid, that was chemically reduced to ursodeoxycholic acid (70% overall yield).
Visualisation of abscisic acid and 12-oxo-phytodienoic acid in immature Phaseolus vulgaris L. seeds using desorption electrospray ionisation-imaging mass spectrometry

NASA Astrophysics Data System (ADS)

Enomoto, Hirofumi; Sensu, Takuya; Sato, Kei; Sato, Futoshi; Paxton, Thanai; Yumoto, Emi; Miyamoto, Koji; Asahina, Masashi; Yokota, Takao; Yamane, Hisakazu

2017-02-01

The plant hormone abscisic acid (ABA) and the jasmonic acid related-compound 12-oxo-phytodienoic acid (OPDA) play crucial roles in seed development, dormancy, and germination. However, a lack of suitable techniques for visualising plant hormones has restricted the investigation of their biological mechanisms. In the present study, desorption electrospray ionisation-imaging mass spectrometry (DESI-IMS), a powerful tool for visualising metabolites in biological tissues, was used to visualise ABA and OPDA in immature Phaseolus vulgaris L. seed sections. The mass spectra, peak values and chemical formulae obtained from the analysis of seed sections were consistent with those determined for ABA and OPDA standards, as were the precursor and major fragment ions observed in tandem mass spectrometry (MS/MS) imaging. Furthermore, the precursor and fragment ion images showed similar distribution patterns. In addition, the localisation of ABA and OPDA using DESI-IMS was confirmed using liquid chromatography-MS/MS (LC-MS/MS). The results indicated that ABA was mainly distributed in the radical and cotyledon of the embryo, whereas OPDA was distributed exclusively in external structures, such as the hilum and seed coat. The present study is the first to report the visualisation of plant hormones using IMS, and demonstrates that DESI-IMS is a promising technique for future plant hormone research.
Visualisation of abscisic acid and 12-oxo-phytodienoic acid in immature Phaseolus vulgaris L. seeds using desorption electrospray ionisation-imaging mass spectrometry

PubMed Central

Enomoto, Hirofumi; Sensu, Takuya; Sato, Kei; Sato, Futoshi; Paxton, Thanai; Yumoto, Emi; Miyamoto, Koji; Asahina, Masashi; Yokota, Takao; Yamane, Hisakazu

2017-01-01

The plant hormone abscisic acid (ABA) and the jasmonic acid related-compound 12-oxo-phytodienoic acid (OPDA) play crucial roles in seed development, dormancy, and germination. However, a lack of suitable techniques for visualising plant hormones has restricted the investigation of their biological mechanisms. In the present study, desorption electrospray ionisation-imaging mass spectrometry (DESI-IMS), a powerful tool for visualising metabolites in biological tissues, was used to visualise ABA and OPDA in immature Phaseolus vulgaris L. seed sections. The mass spectra, peak values and chemical formulae obtained from the analysis of seed sections were consistent with those determined for ABA and OPDA standards, as were the precursor and major fragment ions observed in tandem mass spectrometry (MS/MS) imaging. Furthermore, the precursor and fragment ion images showed similar distribution patterns. In addition, the localisation of ABA and OPDA using DESI-IMS was confirmed using liquid chromatography-MS/MS (LC-MS/MS). The results indicated that ABA was mainly distributed in the radical and cotyledon of the embryo, whereas OPDA was distributed exclusively in external structures, such as the hilum and seed coat. The present study is the first to report the visualisation of plant hormones using IMS, and demonstrates that DESI-IMS is a promising technique for future plant hormone research. PMID:28211480
Improved synthesis of 3 alpha, 7 alpha, 12 alpha, 24 = xi-tetrahydroxy-5 beta-cholestan-26-oic acid.

PubMed

Batta, A K; Tint, G S; Dayal, B; Shefer, S; Salen, G

1982-06-01

This paper describes three simple and short methods for the conversion of cholic acid into cholylaldehyde with protected hydroxyl groups. The first method involves lithium aluminum hydride reduction of the tetrahydropyranyl ether of methyl cholate and oxidation of the resulting primary alcohol with pyridinium chlorochromate. The second method employs diborane for the reduction of the -COOH group to the -CH2OH group, while the third method involves the reduction of 3 alpha, 7 alpha, 12 alpha-triformyloxy-5 beta-cholan-24-oic acid (as the acid chloride) directly into 3 alpha, 7 alpha, 12 alpha-triformyloxy-5 beta-cholan-24-al with TMA-ferride (tetramethylammonium hydridoirontetracarbonyl). The aldehyde obtained by any of the above methods underwent smooth Reformatsky reaction with ethyl alpha-bromopropionate to yield 3 alpha, 7 alpha, 12 alpha, 24 xi-tetrahydroxy-5 beta-cholestan-26-oic acid.
Mechanisms of asbestos-induced squamous metaplasia in tracheobronchial epithelial cells.

PubMed Central

Cameron, G; Woodworth, C D; Edmondson, S; Mossman, B T

1989-01-01

Within 1 to 4 weeks after exposure to asbestos, differentiated rodent and human tracheobronchial epithelial cells in organ culture undergo squamous metaplasia, a putative preneoplastic lesion characterized by conversion of mucociliary cell types to keratinizing cells. The exogenous addition of retinal acetate (RA) to culture medium of hamster tracheal organ cultures reverses preestablished, asbestos-induced squamous metaplasia, although data suggest that the effectiveness of RA decreases as the length of time between exposure to asbestos and initial application of RA increases. alpha-Difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), inhibits squamous metaplasia caused by asbestos or vitamin A deficiency, whereas addition of methylglyoxal bis(guanylhydrazone) (MGBG), a structural analog of spermidine and inhibitor of S-adenosylmethionine decarboxylase, causes an enhancement of metaplasia under both circumstances. Basal cell hyperplasia and increased incorporation of 3H-thymidine by tracheal epithelial cells also are seen after addition of the polyamines, putrescine or spermidine, to tracheal organ cultures, an observation supporting the importance of polyamines in the development of this lesion. The use of retinoids and inhibitors of ODC could be promising as preventive and/or therapeutic approaches for individuals at high risk for development of asbestos-associated diseases. PMID:2924752
Cloning, Baeyer-Villiger Biooxidations, and Structures of the Camphor Pathway 2-Oxo-Δ3-4,5,5-Trimethylcyclopentenylacetyl-Coenzyme A Monooxygenase of Pseudomonas putida ATCC 17453

PubMed Central

Leisch, Hannes; Shi, Rong; Grosse, Stephan; Morley, Krista; Bergeron, Hélène; Cygler, Miroslaw; Iwaki, Hiroaki; Hasegawa, Yoshie

2012-01-01

A dimeric Baeyer-Villiger monooxygenase (BVMO) catalyzing the lactonization of 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetyl-coenzyme A (CoA), a key intermediate in the metabolism of camphor by Pseudomonas putida ATCC 17453, had been initially characterized in 1983 by Ougham and coworkers (H. J. Ougham, D. G. Taylor, and P. W. Trudgill, J. Bacteriol. 153:140–152, 1983). Here we cloned and overexpressed the 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetyl-CoA monooxygenase (OTEMO) in Escherichia coli and determined its three-dimensional structure with bound flavin adenine dinucleotide (FAD) at a 1.95-Å resolution as well as with bound FAD and NADP+ at a 2.0-Å resolution. OTEMO represents the first homodimeric type 1 BVMO structure bound to FAD/NADP+. A comparison of several crystal forms of OTEMO bound to FAD and NADP+ revealed a conformational plasticity of several loop regions, some of which have been implicated in contributing to the substrate specificity profile of structurally related BVMOs. Substrate specificity studies confirmed that the 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetic acid coenzyme A ester is preferred over the free acid. However, the catalytic efficiency (kcat/Km) favors 2-n-hexyl cyclopentanone (4.3 × 105 M−1 s−1) as a substrate, although its affinity (Km = 32 μM) was lower than that of the CoA-activated substrate (Km = 18 μM). In whole-cell biotransformation experiments, OTEMO showed a unique enantiocomplementarity to the action of the prototypical cyclohexanone monooxygenase (CHMO) and appeared to be particularly useful for the oxidation of 4-substituted cyclohexanones. Overall, this work extends our understanding of the molecular structure and mechanistic complexity of the type 1 family of BVMOs and expands the catalytic repertoire of one of its original members. PMID:22267661

The selective conversion of glutamic acid in amino acid mixtures using glutamate decarboxylase--a means of separating amino acids for synthesizing biobased chemicals.

PubMed

Teng, Yinglai; Scott, Elinor L; Sanders, Johan P M

2014-01-01

Amino acids (AAs) derived from hydrolysis of protein rest streams are interesting feedstocks for the chemical industry due to their functionality. However, separation of AAs is required before they can be used for further applications. Electrodialysis may be applied to separate AAs, but its efficiency is limited when separating AAs with similar isoelectric points. To aid the separation, specific conversion of an AA to a useful product with different charge behavior to the remaining compounds is desired. Here the separation of L-aspartic acid (Asp) and L-glutamic acid (Glu) was studied. L-Glutamate α-decarboxylase (GAD, Type I, EC 4.1.1.15) was applied to specifically convert Glu into γ-aminobutyric acid (GABA). GABA has a different charge behavior from Asp therefore allowing a potential separation by electrodialysis. Competitive inhibition and reduced operational stability caused by Asp could be eliminated by maintaining a sufficiently high concentration of Glu. Immobilization of GAD does not reduce the enzyme's initial activity. However, the operational stability was slightly reduced. An initial study on the reaction operating in a continuous mode was performed using a column reactor packed with immobilized GAD. As the reaction mixture was only passed once through the reactor, the conversion of Glu was lower than expected. To complete the conversion of Glu, the stream containing Asp and unreacted Glu might be recirculated back to the reactor after GABA has been removed. Overall, the reaction by GAD is specific to Glu and can be applied to aid the electrodialysis separation of Asp and Glu. © 2014 American Institute of Chemical Engineers.
Transplastomic expression of bacterial L-aspartate-alpha-decarboxylase enhances photosynthesis and biomass production in response to high temperature stress.

PubMed

Fouad, W M; Altpeter, F

2009-10-01

Metabolic engineering for beta-alanine over-production in plants is expected to enhance environmental stress tolerance. The Escherichia coli L-aspartate-alpha-decarboxylase (AspDC) encoded by the panD gene, catalyzes the decarboxylation of L-aspartate to generate beta-alanine and carbon dioxide. The constitutive E. coli panD expression cassette was co-introduced with the constitutive, selectable aadA expression cassette into the chloroplast genome of tobacco via biolistic gene transfer and homologous recombination. Site specific integration of the E. coli panD expression cassette into the chloroplast genome and generation of homotransplastomic plants were confirmed by PCR and Southern blot analysis, respectively, following plant regeneration and germination of seedlings on selective media. PanD expression was verified by assays based on transcript detection and in vitro enzyme activity. The AspDC activities in transplastomic plants expressing panD were drastically increased by high-temperature stress. beta-Alanine accumulated in transplastomic plants at levels four times higher than in wildtype plants. Analysis of chlorophyll fluorescence on plants subjected to severe heat stress at 45 degrees C under light verified that photosystem II (PSII) in transgenic plants had higher thermotolerance than in wildtype plants. The CO(2) assimilation of transplastomic plants expressing panD was more tolerant to high temperature stress than that of wildtype plants, resulting in the production of 30-40% more above ground biomass than wildtype control. The results presented indicate that chloroplast engineering of the beta-alanine pathway by over-expression of the E. coli panD enhances thermotolerance of photosynthesis and biomass production following high temperature stress.
A switch between DNA polymerases δ and λ promotes error-free bypass of 8-oxo-G lesions

PubMed Central

Markkanen, Enni; Castrec, Benoît; Villani, Giuseppe; Hübscher, Ulrich

2012-01-01

7,8-Dihydro-8-oxoguanine (8-oxo-G) is a highly abundant and mutagenic lesion. Replicative DNA polymerases (pols) are slowed down at 8-oxo-G and insert both correct cytosine (C) and incorrect adenine (A) opposite 8-oxo-G, but they preferentially extend A:8-oxo-G mispairs. Nevertheless, 8-oxo-G bypass is fairly accurate in vivo. Thus, the question how correct bypass of 8-oxo-G lesions is accomplished despite the poor extension of C:8-oxo-G base pairs by replicative pols remains unanswered. Here we show that replicative pol δ pauses in front of 8-oxo-G and displays difficulties extending from correct C:8-oxo-G in contrast to extension from incorrect A:8-oxo-G. This leads to stalling of pol δ at 8-oxo-G after incorporation of correct C. This stalling at C:8-oxo-G can be overcome by a switch from pol δ to pols λ, β, or η, all of which are able to assist pol δ in 8-oxo-G bypass by translesion synthesis (TLS). Importantly, however, only pol λ selectively catalyzes the correct TLS past 8-oxo-G, whereas pols β and η show no selectivity and even preferentially enhance incorrect TLS. The selectivity of pol λ to promote the correct bypass depends on its N-terminal domain. Furthermore, pol λ−/− mouse embryonic fibroblast extracts display reduced 8-oxo-G TLS. Finally, the correct bypass of 8-oxo-G in gapped plasmids in mouse embryonic fibroblasts and HeLa cells is promoted in the presence of pol λ. Our findings suggest that even though 8-oxo-G is not a blocking lesion per se, correct replication over 8-oxo-G is promoted by a pol switch between pols δ and λ. PMID:23175785
New alkamides from maca (Lepidium meyenii).

PubMed

Zhao, Jianping; Muhammad, Ilias; Dunbar, D Chuck; Mustafa, Jamal; Khan, Ikhlas A

2005-02-09

Maca (Lepidium meyenii) has been used as a food in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements, with claims of anabolic and aphrodisiac effects, although the biologically active principles are not fully known. In an earlier chemical investigation, two new alkamides and a novel fatty acid, as well as the N-hydroxypyridine derivative, macaridine, were isolated from L. meyenii. Further examination has led to the isolation of five additional new alkamides, namely, N-benzyl-9-oxo-12Z-octadecenamide (1), N-benzyl-9-oxo-12Z,15Z-octadecadienamide (2), N-benzyl-13-oxo-9E,11E-octadecadienamide (3), N-benzyl-15Z-tetracosenamide (4), and N-(m-methoxybenzyl)hexadecanamide (5). Their structures were established by spectrometric and spectroscopic methods including ESI-HRMS, EI-MS, (1)H, (13)C, and 2D NMR, as well as (1)H-(15)N 2D HMBC experiments. In addition, the identity of N-benzyl-15Z-tetracosenamide (4) was confirmed by synthesis. These compounds have been found from only L. meyenii and could be used as markers for authentication and standardization.
Purification and biological evaluation of the metabolites produced by Streptomyces sp. TK-VL_333.

PubMed

Kavitha, Alapati; Prabhakar, Peddikotla; Vijayalakshmi, Muvva; Venkateswarlu, Yenamandra

2010-06-01

An Actinobacterium strain isolated from laterite soils of the Guntur region was identified as Streptomyces sp. TK-VL_333 by 16S rRNA analysis. Cultural, morphological and physiological characteristics of the strain were recorded. The secondary metabolites produced by the strain cultured on galactose-tyrosine broth were extracted and concentrated followed by defatting of the crude extract with cyclohexane to afford polar and non-polar residues. Purification of the two residues by column chromatography led to isolation of five polar and one non-polar fraction. Bioactivity- guided fractions were rechromatographed on a silica gel column to obtain four compounds, namely 1H-indole-3-carboxylic acid, 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one and acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester from three active polar fractions and 8-methyl decanoic acid from one non-polar fraction. The structure of the compounds was elucidated on the basis of FT-IR, mass and NMR spectroscopy. The antimicrobial activity of the bioactive compounds produced by the strain was tested against the bacteria and fungi and expressed in terms of minimum inhibitory concentration. Antifungal activity of indole-3-carboxylic acid was further evaluated under in vitro and in vivo conditions. This is the first report of 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one, acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester and 8-methyl decanoic acid from the genus Streptomyces. 2010 Elsevier Masson SAS. All rights reserved.
Advantages of analyzing postmortem brain samples in routine forensic drug screening-Case series of three non-natural deaths tested positive for lysergic acid diethylamide (LSD).

PubMed

Mardal, Marie; Johansen, Sys Stybe; Thomsen, Ragnar; Linnet, Kristian

2017-09-01

Three case reports are presented, including autopsy findings and toxicological screening results, which were tested positive for the potent hallucinogenic drug lysergic acid diethylamide (LSD). LSD and its main metabolites were quantified in brain tissue and femoral blood, and furthermore hematoma and urine when available. LSD, its main metabolite 2-oxo-3-hydroxy-LSD (oxo-HO-LSD), and iso-LSD were quantified in biological samples according to a previously published procedure involving liquid-liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). LSD was measured in the brain tissue of all presented cases at a concentration level from 0.34-10.8μg/kg. The concentration level in the target organ was higher than in peripheral blood. Additional psychoactive compounds were quantified in blood and brain tissue, though all below toxic concentration levels. The cause of death in case 1 was collision-induced brain injury, while it was drowning in case 2 and 3 and thus not drug intoxication. However, the toxicological findings could help explain the decedent's inability to cope with brain injury or drowning incidents. The presented findings could help establish reference concentrations in brain samples and assist in interpretation of results from forensic drug screening in brain tissue. This is to the author's knowledge the first report of LSD, iso-LSD, and oxo-HO-LSD measured in brain tissue samples. Copyright © 2017 Elsevier B.V. All rights reserved.
Biodegradation of the xenobiotic organic disulphide 4,4'-dithiodibutyric acid by Rhodococcus erythropolis strain MI2 and comparison with the microbial utilization of 3,3'-dithiodipropionic acid and 3,3'-thiodipropionic acid.

PubMed

Wübbeler, Jan Hendrik; Bruland, Nadine; Wozniczka, Milena; Steinbüchel, Alexander

2010-04-01

Application of the non-toxic 3,3'-thiodipropionic acid (TDP) and 3,3'-dithiodipropionic acid (DTDP) as precursors for the microbial production of polythioesters (PTEs), a class of biologically persistent biopolymers containing sulphur in the backbone, was successfully established previously. However, synthesis of PTEs containing 4-mercaptobutyrate (4MB) as building blocks could not be achieved. The very harmful 4MB is not used as a PTE precursor or as the carbon source for growth by any known strain. As a promising alternative, the harmless oxidized disulfide of two molecules of 4MB, 4,4'-dithiodibutyric acid (DTDB), was employed for enrichments of bacterial strains capable of biodegradation. Investigation of novel precursor substrates for PTEs and comparison of respective strains growing on TDP, DTDP and DTDB as sole carbon source was accomplished. A broad variety of bacteria capable of using one of these organic sulphur compounds were isolated and compared. TDP and DTDP were degraded by several strains belonging to different genera, whereas all DTDB-utilizing strains were affiliated to the species Rhodococcus erythropolis. Transposon mutagenesis of R. erythropolis strain MI2 and screening of 7500 resulting mutants yielded three mutants exhibiting impaired growth on DTDB. Physiological studies revealed production of volatile hydrogen sulphide and accumulation of significant amounts of 4MB, 4-oxo-4-sulphanylbutanoic acid and succinic acid in the culture supernatants. Based on this knowledge, a putative pathway for degradation of DTDB was proposed: DTDB could be cleaved into two molecules of 4MB, followed by an oxidation yielding 4-oxo-4-sulphanylbutanoic acid. A putative desulphydrase probably catalyses the abstraction of sulphur, thereby generating succinic acid and hydrogen sulphide.
40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. 721.10300 Section 721.10300 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.10300 Benzeneacetic acid, .alpha.-chloro-.alpha...
40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. 721.10300 Section 721.10300 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.10300 Benzeneacetic acid, .alpha.-chloro-.alpha...
40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. 721.10300 Section 721.10300 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.10300 Benzeneacetic acid, .alpha.-chloro-.alpha...
Identification of dicarboxylic acids and aldehydes of PM10 and PM2.5 aerosols in Nanjing, China

NASA Astrophysics Data System (ADS)

Wang, Gehui; Niu, Sulian; Liu, Caie; Wang, Liansheng

In this study aerosol samples of PM10 and PM2.5 collected from 18 February 2001 to 1 May 2001 in Nanjing, China were analyzed for their water-soluble organic compounds. A series of homologous dicarboxylic acids (C 2-10) and two kinds of aldehydes (methylglyoxal and 2-oxo-malonaldehyde) were detected by GC and GC/MS. Among the identified compounds, the concentration of oxalic acid was the highest at all the five sites, which ranged from 178 to 1423 ng/m 3. The second highest concentration of dicarboxylic acids were malonic and succinic acids, which ranged from 26.9 to 243 ng/m 3. Higher level of azelaic acid was also observed, of which the maximum was 301 ng/m 3. As the highest fraction of dicarboxylic acids, oxalic acid comprised from 28% to 86% of total dicarboxylic acids in PM10 and from 41% to 65% of total dicarboxylic acids in PM2.5. The dicarboxylic acids (C 2, C 3, C 4) together accounted for 38-95% of total dicarboxylic acids in PM10 and 59-87% of dicarboxylic acids in PM2.5. In this study, the total dicarboxylic acids accounted for 2.8-7.9% of total organic carbon (TOC) of water-soluble matters for PM10 and 3.4-11.8% of TOC for PM2.5. All dicarboxylic acids detected in this study together accounted for about 1% of particle mass. The concentration of azelaic acid was higher at one site than others, which may be resulted from higher level of volatile fat used for cooking. The amounts of dicarboxyic acids (C 2,3,4,9) and 2-oxo-malonaldehyde of PM2.5 were higher in winter and lower in spring. Compared with other major metropolitans in the world, the level of oxalic acid concentration of Nanjing is much higher, which may be contributed to higher level of particle loadings, especially for fine particles.
Higher plant metabolism and energetics in hypogravity: Amino acid metabolism in higher plants

NASA Technical Reports Server (NTRS)

Mazelis, M.

1976-01-01

Laboratory's investigation into the amino acid metabolism of dwarf marigolds exposed to an environment of simulated hypogravity is summarized. Using both in vivo, and/or in vitro studies, the following effects of hypogravitational stress have been shown: (1) increased proline incorporation into cell wall protein, (2) inhibition of amino acid decarboxylation, (3) decrease in glutamic acid decarboxylase activity; and (4) decrease in the relative amount of a number of soluble amino acids present in deproteinized extracts of marigold leaves. It is concluded from these data there are several rapid, major alterations in amino acid metabolism associated with hypogravitational stress in marigolds. The mechanism(s) and generality of these effects with regard to other species is still unknown.
Induction of hepatic and renal ornithine decarboxylase by cobalt and other metal ions in rats.

PubMed Central

Yoshida, T; Numazawa, S; Kuroiwa, Y

1986-01-01

We previously showed that Cd2+ is able to induce hepatic and renal ornithine decarboxylase (ODC). In addition to Cd2+, the administration of Co2+ and other metal ions such as Se2+, Zn2+ and Cr2+ produced a significant increase of hepatic and/or renal ODC activity. Of the metal ions used in this study, Co2+ produced the greatest increase of ODC activity. The maximum increases in hepatic and renal ODC activity, to respectively 70 and 14 times the control values in male rats, were observed 6 h after the administration of Co2+. A similar response was seen in the liver, but not in the kidney, of female rats. Thereafter, ODC activity gradually returned to control values in the liver, but it was profoundly decreased to 7% of the control value at 24 h in the kidney. The pretreatment of animals with either actinomycin D or cycloheximide almost completely blocked the Co2+-mediated increase of ODC activity. Co2+ complexed with either cysteine or glutathione (GSH) failed to induce ODC. Depletion of hepatic GSH content by treatment of rats with diethyl maleate greatly enhanced the inducing effect of Co2+ on ODC. The inhibitors of ODC, 1,3-diaminopropane and alpha-difluoromethylornithine, were able to inhibit the induction of the enzyme, without affecting the induction of haem oxygenase by Co2+. Methylglyoxal bis(guanylhydrazone), an inhibitor of S-adenosylmethionine decarboxylase, significantly inhibited the Co2+-mediated induction of both ODC and haem oxygenase. It is suggested that the inducing effects of Co2+ on ODC and haem oxygenase are brought about in a similar manner. PMID:3754136
Enantiomeric excesses in meteoritic amino acids

NASA Technical Reports Server (NTRS)

Cronin, J. R.; Pizzarello, S.

1997-01-01

Gas chromatographic-mass spectral analyses of the four stereoisomers of 2-amino-2,3-dimethylpentanoic acid (dl-alpha-methylisoleucine and dl-alpha-methylalloisoleucine) obtained from the Murchison meteorite show that the L enantiomer occurs in excess (7.0 and 9.1%, respectively) in both of the enantiomeric pairs. Similar results were obtained for two other alpha-methyl amino acids, isovaline and alpha-methylnorvaline, although the alpha hydrogen analogs of these amino acids, alpha-amino-n-butyric acid and norvaline, were found to be racemates. With the exception of alpha-amino-n-butyric acid, these amino acids are either unknown or of limited occurrence in the biosphere. Because carbonaceous chondrites formed 4.5 billion years ago, the results are indicative of an asymmetric influence on organic chemical evolution before the origin of life.
Kinetic and Structural Characterization of a Heterohexamer 4-Oxalocrotonate Tautomerase from Chloroflexus aurantiacus J-10-fl: Implications for Functional and Structural Diversity in the Tautomerase Superfamily

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burks, Elizabeth A.; Fleming, Christopher D.; Mesecar, Andrew D.

2010-09-30

4-Oxalocrotonate tautomerase (4-OT) isozymes play prominent roles in the bacterial utilization of aromatic hydrocarbons as sole carbon sources. These enzymes catalyze the conversion of 2-hydroxy-2,4-hexadienedioate (or 2-hydroxymuconate) to 2-oxo-3-hexenedioate, where Pro-1 functions as a general base and shuttles a proton from the 2-hydroxyl group of the substrate to the C-5 position of the product. 4-OT, a homohexamer from Pseudomonas putida mt-2, is the most extensively studied 4-OT isozyme and the founding member of the tautomerase superfamily. A search of five thermophilic bacterial genomes identified a coded amino acid sequence in each that had been annotated as a tautomerase-like protein butmore » lacked Pro-1. However, a nearby sequence has Pro-1, but the sequence is not annotated as a tautomerase-like protein. To characterize this group of proteins, two genes from Chloroflexus aurantiacus J-10-fl were cloned, and the corresponding proteins were expressed. Kinetic, biochemical, and X-ray structural analyses show that the two expressed proteins form a functional heterohexamer 4-OT (hh4-OT), composed of three {alpha}{beta} dimers. Like the P. putida enzyme, hh4-OT requires the amino-terminal proline and two arginines for the conversion of 2-hydroxymuconate to the product, implicating an analogous mechanism. In contrast to 4-OT, hh4-OT does not exhibit the low-level activity of another tautomerase superfamily member, the heterohexamer trans-3-chloroacrylic acid dehalogenase (CaaD). Characterization of hh4-OT enables functional assignment of the related enzymes, highlights the diverse ways the {beta}-{alpha}-{beta} building block can be assembled into an active enzyme, and provides further insight into the molecular basis of the low-level CaaD activity in 4-OT.« less
Asymmetric Synthesis of β-Amino Amides by Catalytic Enantioconvergent 2-Aza-Cope Rearrangement

PubMed Central

Goodman, C. Guy; Johnson, Jeffrey S.

2015-01-01

Dynamic kinetic resolutions of α-stereogenic-β-formyl amides in asymmetric 2-aza-Cope rearrangements are described. Chiral phosphoric acids catalyze this rare example of a non-hydrogenative DKR of a β-oxo acid derivative. The [3,3]-rearrangement occurs with high diastereo- and enantiocontrol, forming β-imino amides that can be deprotected to the primary β-amino amide or reduced to the corresponding diamine. PMID:26561873
Pentafluorophenylammonium triflate (PFPAT) catalyzed facile construction of substituted chromeno[2,3-d]pyrimidinone derivatives and their antimicrobial activity

PubMed Central

Ghashang, Majid; Mansoor, Syed Sheik; Aswin, Krishnamoorthy

2013-01-01

A new, simple thermally efficient and solvent-free condensation of 2-amino-3-cyano-6-methyl-4-phenyl-4H-pyran-5-ethylcarboxylate derivatives with coumarin-3-carboxylic acid employing pentafluorophenylammonium triflate (PFPAT) as an inexpensive organocatalyst for the synthesis of a series of ethyl 4,5-dihydro 7-methyl-2-(2-oxo-2H-chromen-3-yl)-4-oxo-5-aryl-3H-chromeno[2,3-d]pyrimidine-6-carboxylate derivatives is described. This method has the advantages of high yields, a cleaner reaction, simple methodology, short reaction times, easy workup, and greener conditions. All the compounds were evaluated for their in vitro antimicrobial activity against different bacterial and fungal strains. PMID:25685489
α-VINYLLYSINE AND α-VINYLARGININE ARE TIME-DEPENDENT INHIBITORS OF THEIR COGNATE DECARBOXYLASES

PubMed Central

Berkowitz, David B.; Jahng, Wan-Jin; Pedersen, Michelle L.

2017-01-01

(±)-α-Vinyllysine and (±)-α-vinylarginine display time-dependent inhibition of L-lysine decarboxylase from B. cadaveris, and L-arginine decarboxylase from E. coli, respectively. A complete Kitz-Wilson analysis has been performed using a modification of the Palcic continuous UV assay for decarboxylase activity. PMID:29123334
TaOPR2 encodes a 12-oxo-phytodienoic acid reductase involved in the biosynthesis of jasmonic acid in wheat (Triticum aestivum L.).

PubMed

Wang, Yukun; Yuan, Guoliang; Yuan, Shaohua; Duan, Wenjing; Wang, Peng; Bai, Jianfang; Zhang, Fengting; Gao, Shiqing; Zhang, Liping; Zhao, Changping

2016-01-29

The 12-oxo-phytodienoic acid reductases (OPRs) are involved in the various processes of growth and development in plants, and classified into the OPRⅠ and OPRⅡ subgroups. In higher plants, only OPRⅡ subgroup genes take part in the biosynthesis of endogenous jasmonic acid. In this study, we isolated a novel OPRⅡ subgroup gene named TaOPR2 (GeneBank accession: KM216389) from the thermo-sensitive genic male sterile (TGMS) wheat cultivar BS366. TaOPR2 was predicted to encode a protein with 390 amino acids. The encoded protein contained the typical oxidored_FMN domain, the C-terminus peroxisomal-targeting signal peptide, and conserved FMN-binding sites. TaOPR2 was mapped to wheat chromosome 7B and located on peroxisome. Protein evolution analysis revealed that TaOPR2 belongs to the OPRⅡ subgroup and shares a high degree of identity with other higher plant OPR proteins. The quantitative real-time PCR results indicated that the expression of TaOPR2 is inhibited by abscisic acid (ABA), salicylic acid (SA), gibberellic acid (GA3), low temperatures and high salinity. In contrast, the expression of TaOPR2 can be induced by wounding, drought and methyl jasmonate (MeJA). Furthermore, the transcription level of TaOPR2 increased after infection with Puccinia striiformis f. sp. tritici and Puccinia recondite f. sp. tritici. TaOPR2 has NADPH-dependent oxidoreductase activity. In addition, the constitutive expression of TaOPR2 can rescue the male sterility phenotype of Arabidopsis mutant opr3. These results suggest that TaOPR2 is involved in the biosynthesis of jasmonic acid (JA) in wheat. Copyright © 2016 Elsevier Inc. All rights reserved.
Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production.

PubMed

Tajabadi, Naser; Baradaran, Ali; Ebrahimpour, Afshin; Rahim, Raha A; Bakar, Fatimah A; Manap, Mohd Yazid A; Mohammed, Abdulkarim S; Saari, Nazamid

2015-07-01

Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL.... Requirements as specified in § 721.80(j) (additive in rubber, i.e. as reinforcing agent; additive in plastics...
40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL.... Requirements as specified in § 721.80(j) (additive in rubber, i.e. as reinforcing agent; additive in plastics...
Genomic evaluation of oxalate-degrading transgenic soybean in response to Sclerotinia sclerotiorum infection

USDA-ARS?s Scientific Manuscript database

Oxalate oxidases catalyze the degradation of oxalic acid (OA). Highly resistant transgenic soybean carrying an oxalate oxidase (OxO) gene and its susceptible parent soybean line, AC Colibri, were tested for genome-wide gene expression in response to the necrotrophic, OA producing pathogen Sclerotini...
Regulation of S-adenosylmethionine decarboxylase by polyamines in Ehrlich ascites-carcinoma cells grown in culture

PubMed Central

Alhonen-Hongisto, Leena

1980-01-01

1. The mechanism of stimulation of S-adenosylmethionine decarboxylase (EC 4.1.1.50) activity by inhibitors of ornithine decarboxylase (EC 4.1.1.17), namely dl-α-difluoromethylornithine, 1,3-diaminopropane and 1,3-diaminopropan-2-ol, was studied in Ehrlich ascites-tumour cells grown in suspension cultures. 2. Difluoromethylornithine and diaminopropane, although decreasing the content of putrescine and spermidine, markedly stimulated adenosylmethionine decarboxylase activity after exposure of the cells to the drugs for 8h, whereas the effect of diaminopropanol only became apparent many hours later. In tumour cells exposed to any of the inhibitors, a close negative correlation existed between the activity of adenosylmethionine decarboxylase and the intracellular concentration of spermidine and/or spermidine plus spermine, suggesting that a depletion of higher polyamines triggered enhancement of adenosylmethionine decarboxylase activity. 3. The mechanism of difluoromethylornithine- and diaminopropane-induced stimulation of adenosylmethionine decarboxylase involved (a) a marked increase in the apparent half-life of the enzyme and (b) an induction of enhanced enzyme synthesis. Diaminopropanol seemed to act solely via an induction mechanism. 4. The increased adenosylmethionine decarboxylase activity elicited by difluoromethylornithine could be restored to control values by micromolar concentrations of exogenous spermidine and spermine in 4h and by putrescine in 22h. In addition to the natural polyamines, elevated adenosylmethionine decarboxylase activity could be repressed by 3,3′-iminodipropylamine, a close analogue of spermidine, but not by non-physiological diamines. 5. Addition of spermidine and actinomycin D to cultures treated with difluoromethylornithine produced a comparable decay of enhanced adenosylmethionine decarboxylase activity (with an apparent half-life of about 2.5h), whereas the effect of cycloheximide was much more rapid. The present results suggest that polyamines may regulate adenosylmethionine decarboxylase at the transcriptional level of gene expression. PMID:6781485
Bile alcohol metabolism in man. Conversion of 5beta-cholestane-3alpha, 7alpha,12alpha, 25-tetrol to cholic acid.

PubMed Central

Salen, G; Shefer, S; Setoguchi, T; Mosbach, E H

1975-01-01

To study the role of C25-HYDROXY BILE ALCOHOLS AS PRECURSORS OF CHOlic acid, [G-3-H]5beta-cholestane-3alpha,7alpha12alpha,25-tetrol was administered intravenously to two subjects with cerebrotendinous xanthomatosis (CTX) and two normal individuals. One day after pulse labeling, radioactivity was present in the cholic acid isolated from the bile and feces of the subjects with CTX and the bile of the normal individuals. In the two normal subjects, the sp act decay curves of [G-3-H]-cholic acid were exponential, and no traces of [G-3-H]-5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol were detected. In contrast, appreciable quantities of labeled 5beta-cholestane-3alpha,-7aopha,12alpha,25-tetrol were present in the bile and feces of the CTX subjects. The sp act vs. time curves of fecal [G-3-H]5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol and [G-3-H]-cholic acid showed a precursor-product relationship. Although these results suggest that 5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol may be a precursor of cholic acid in man, the possibility that C26-hydroxy intermediates represent the normal pathway can not be excluded. PMID:1141434
The chemistry of aminoguanidine derivatives - preparation, crystal structure, thermal properties, and molecular docking studies of aminoguanidinium salts of several carboxylic acids

NASA Astrophysics Data System (ADS)

Selvakumar, Rajendran; Geib, Steven J.; Muthu Sankar, Aathi; Premkumar, Thathan; Govindarajan, Subbaiah

2015-11-01

The reaction of aminoguanidine bicarbonate (Amg) with oxamic, oxalic, malonic and sulfoacetic acids yielded (AmgH)H2NOC-COO (1), OOC-CONHNHC(NH2)NH2 (2) (AmgH)HOOC-CH2-COO (3) and O3S-CH2-CONHNHC(NH2)NH2 (4), respectively. For the first time, we studied the salt-forming ability of aminoguanidine with several carboxylic acids, such as oxamic, oxalic, malonic and sulphoacetic acids. We also compared the structural and thermal properties of these salts. Oxamic and malonic acids form only mono-aminoguanidinium salts, whereas oxalic acid mainly forms di-aminoguanidinium oxalate. In addition, oxalic acid forms guanylhydrazido-oxalic acid which exists as zwitter ion. Unlike other acids, sulfoacetic acid readily forms only the zwitter ionic salts (2-guanylhydrazido-oxo-methanesulfonic acid) rather than the usual simple salt. This result may be a result of the highly acidic nature of the sulfonic group, which favors acid catalyzed condensation. More significantly, for the first time, the ability guanylhydrazido-oxalic acid (2) and 2-guanylhydrazido-oxo-methanesulfonic acid (4) to inhibit human butyrylcholinesterase (human BChE) receptor has been studied with a molecular docking approach. The binding of the compounds to human BChE was examined as it is crucial to understanding the biological significance of aminoguanidine derivatives. The compounds were identified and characterized by analytical, FT-IR spectroscopic and thermal studies. Furthermore, the structures of compounds 1, 2 and 4 were confirmed by single X-ray diffraction studies. Compounds 1 and 2 crystallized in a monoclinic crystal system with P21/c and Cc space groups, respectively, whereas compound 4 crystalized in an orthorhombic system with a Pbca space group. All the compounds (1-4) underwent endo- followed by exothermic decomposition in the temperature range from 130 to 600 °C to yield gaseous products.
Hypotensive effect of alpha-lipoic acid after a single administration in rats.

PubMed

Dudek, Magdalena; Razny, Katarzyna; Bilska-Wilkosz, Anna; Iciek, Malgorzata; Sapa, Jacek; Wlodek, Lidia; Filipek, Barbara

2016-05-01

The effect of alpha-lipoic acid on blood pressure was investigated many times in chronic studies, but there are no studies on the effect of this compound after a single administration. Alpha-lipoic acid is a drug used in diabetic neuropathy, often in obese patients, to treat hypertension. Therefore, knowledge of the potential antihypertensive effect of alpha-lipoic acid even after a single dose and possibly too much pressure reduction is interesting and useful. The mechanism of the hypotensive effect of alpha-lipoic acid was examined in normotensive rats in vivo after a single intraperitoneal administration, blood pressure in the left carotid artery of the rats was measured prior to the administration of the compounds (alpha- lipoic acid and/or glibenclamide) and 80 min thereafter. Alpha-lipoic acid at a dosage of 50 mg/kg b.w. i.p. significantly decreased the blood pressure from the 50th min after drug administration. This cardiovascular effect of this compound was reversed by glibenclamide, a selective KATP blocker. Glibenclamide alone at this dose did not significantly affect the blood pressure. Statistical significance was evaluated using two-way ANOVA. This suggests that alpha-lipoic acid affects ATP-dependent potassium channels. It is possible that this is an indirect effect of hydrogen sulfide because alpha-lipoic acid can increase its concentration. The results obtained in this study are very important because the patients taking alpha-lipoic acid may be treated for co-existing hypertension. Therefore, the possibility of blood pressure lowering by alpha-lipoic acid should be taken into account, although it does not lead to excessive orthostatic hypotension.
Saturated mutagenesis of ketoisovalerate decarboxylase V461 enabled specific synthesis of 1-pentanol via the ketoacid elongation cycle.

PubMed

Chen, Grey S; Siao, Siang Wun; Shen, Claire R

2017-09-12

Iterative ketoacid elongation has been an essential tool in engineering artificial metabolism, in particular the synthetic alcohols. However, precise control of product specificity is still greatly challenged by the substrate promiscuity of the ketoacid decarboxylase, which unselectively hijacks ketoacid intermediates from the elongation cycle along with the target ketoacid. In this work, preferential tuning of the Lactococcus lactis ketoisovalerate decarboxylase (Kivd) specificity toward 1-pentanol synthesis was achieved via saturated mutagenesis of the key residue V461 followed by screening of the resulting alcohol spectrum. Substitution of V461 with the small and polar amino acid glycine or serine significantly improved the Kivd selectivity toward the 1-pentanol precursor 2-ketocaproate by lowering its catalytic efficiency for the upstream ketoacid 2-ketobutyrate and 2-ketovalerate. Conversely, replacing V461 with bulky or charged side chains displayed severely adverse effect. Increasing supply of the iterative addition unit acetyl-CoA by acetate feeding further drove 2-ketoacid flux into the elongation cycle and enhanced 1-pentanol productivity. The Kivd V461G variant enabled a 1-pentanol production specificity around 90% of the total alcohol content with or without oleyl alcohol extraction. This work adds insight to the selectivity of Kivd active site.
Chemical of Vitex trifolia.

PubMed

Liu, Quan-Yu; Chen, Yong-Sheng; Wang, Fei; Chen, Shi-Wu; Zhang, Yong-Hong

2014-06-01

A new steroidal ester, beta-rosaterol palmitate (1) along with ten known compounds, uvaol(2), 3-epi-ursolic acid (3), 2alpha, 3beta, 24-trihydroxyolean-12-en-28-oic acid (4), 2alpha, 3alpha, 24-trihydroxyurs-12-en-28-oic acid (5), 2alpha, 3alpha, 24-trihydroxyolean-12-en-28-oic acid (6), 2alpha, 3alpha, 24-trihydroxyolean-12-en-28-oic acid-28-O-beta-D-glucopyranosyl ester (7), (Z)-9-hexadecenoic acid (8), octacosyl alcohol (9), beta-sitosterol (10) and beta-daucosterol (11), has been isolated from the stems and leaves of Vitex trifolia. Their structures were elucidated using a combination of 1D and 2D NMR techniques (COSY, HMQC, and HMBC)and HR-ESI-MS analyses. Compounds 2-7 were isolated from this plant for the first time.
Bacterial synthesis of N-hydroxycinnamoyl phenethylamines and tyramines.

PubMed

Sim, Geun Young; Yang, So-Mi; Kim, Bong Gyu; Ahn, Joong-Hoon

2015-10-13

Hydroxycinnamic acids (HCAs) including cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid, are C6-C3 phenolic compounds that are synthesized via the phenylpropanoid pathway. HCAs serve as precursors for the synthesis of lignins, flavonoids, anthocyanins, stilbenes and other phenolic compounds. HCAs can also be conjugated with diverse compounds including quinic acid, hydroxyl acids, and amines. Hydroxycinnamoyl (HC) amine conjugates such as N-HC tyramines and N-HC phenethylamines have been considered as potential starting materials to develop antiviral and anticancer drugs. We synthesized N-HC tyramines and N-HC phenethylamines using three different approaches in Escherichia coli. Five N-HC phenethylamines and eight N-HC tyramines were synthesized by feeding HCAs and phenethylamine or tyramine to E. coli harboring 4CL (encoding 4-coumarate CoA:ligase) and either SHT (encoding phenethylamine N-HC transferase) or THT (encoding tyramine N-HC transferase). Also, N-(p-coumaroyl) phenethylamine and N-(p-coumaroyl) tyramine were synthesized from p-coumaric acid using E. coli harboring an additional gene, PDC (encoding phenylalanine decarboxylase) or TDC (encoding tyrosine decarboxylase). Finally, we synthesized N-(p-coumaroyl) phenethylamine and N-(p-coumaroyl) tyramine from glucose by reconstructing the metabolic pathways for their synthesis in E. coli. Productivity was maximized by optimizing the cell concentration and incubation temperature. We reconstructed the metabolic pathways for synthesis of N-HC tyramines and N-HC phenethylamines by expressing several genes including 4CL, TST or SHT, PDC or TDC, and TAL (encoding tyrosine ammonia lyase) and engineering the shikimate metabolic pathway to increase endogenous tyrosine concentration in E. coli. Approximately 101.9 mg/L N-(p-coumaroyl) phenethylamine and 495.4 mg/L N-(p-coumaroyl) tyramine were synthesized from p-coumaric acid. Furthermore, 152.5 mg/L N-(p-coumaroyl) phenethylamine and 94.7 mg/L N-(p-coumaroyl) tyramine were synthesized from glucose.
Ingasaponin, a complex triterpenoid saponin with immunological adjuvant activity from Inga laurina.

PubMed

Cruz, Maria de Fátima Simão Jucá; Pereira, Gabriela Moysés; Ribeiro, Marcela Gonçalves; da Silva, Ari Miranda; Tinoco, Luzineide Wanderley; da Silva, Bernadete Pereira; Parente, José Paz

2016-02-01

As part of our search of bioactive saponins from Brazilian plants, phytochemical study of the seeds of Inga laurina led to the isolation of a new complex triterpenoid saponin, named ingasaponin. It is the first saponin isolated from a species of Inga genus. It was isolated by using chromatographic methods and its structural elucidation was performed using detailed analyses of (1)H and (13)C NMR spectra including 2D-NMR spectroscopic techniques and chemical conversions. Its structure was established as 21-[[(2E,6S)-6-[[6-deoxy-4-O-[(2E,6S)-6-[(β-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(β-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(β-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(β-D-glucopyranosyl)oxy]-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]oxy]-16-hydroxy-3-[[O-β-D-xylopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-β-D-glucopyranosyl]oxy]-(3β,16α,21β)-olean-12-en-28-oic acid O-α-L-arabinofuranosyl-(1 → 4)-O-[β-D-glucopyranosyl-(1 → 3)]-O-6-deoxy-α-L-mannopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (1). The hemolytic potential of 1 was evaluated using in vitro assays, and its adjuvant activity on the cellular immune response against ovalbumin antigen was investigated using in vivo models. Copyright © 2015 Elsevier Ltd. All rights reserved.
Synthesis and spectral characterization of trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes with Schiff bases.

PubMed

Singh, Atresh Kumar; Singh, Alok Kumar

2012-10-01

Some novel trinuclear, oxo-centered, carboxylate-bridged, mixed-valence iron complexes of the general formula [Fe(3)O(OOCR)(3)(SB)(3)L(3)] (where R=C(13)H(27), C(15)H(31) or C(17)H(35,) HSB=Schiff bases and L=Ethanol) have been synthesized by the stepwise substitutions of acetate ions from μ(3)-oxo-hexa(acetato)tri(aqua)iron(II)diiron(III), first with straight chain carboxylic acids and then with Schiff bases. The complexes were characterized by elemental analyses, molecular weight determinations and spectral (electronic, infrared, FAB mass, Mössbauer and powder XRD) studies. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bridging nature of carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Mössbauer spectroscopic studies indicated two quadrupole-split doublets due to Fe(II) and Fe(III) ions at 80, 200 and 295K, confirming the complexes are mixed-valence species. This was also supported by the observed electronic spectra of the complexes. Magnetic susceptibility measurements displayed octahedral geometry around iron in mixed-valence state and a net antiferromagnetic exchange coupling via μ-oxo atom. Trinuclear nature of the complexes was confirmed by their molecular weight determination and FAB mass spectra. A plausible structure for these complexes has been established on the basis of spectral and magnetic moment data. Copyright © 2012 Elsevier B.V. All rights reserved.
Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi

2011-04-22

Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a humanmore » adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected effects of PPAR{alpha} activation are very valuable for managing diabetic conditions accompanied by obesity, because PPAR{gamma} agonists, usually used as antidiabetic drugs, induce excessive lipid accumulation in adipocytes in addition to improvement of insulin resistance.« less
Differential Regulation of Glutamic Acid Decarboxylase Gene Expression after Extinction of a Recent Memory vs. Intermediate Memory

ERIC Educational Resources Information Center

Sangha, Susan; Ilenseer, Jasmin; Sosulina, Ludmila; Lesting, Jorg; Pape, Hans-Christian

2012-01-01

Extinction reduces fear to stimuli that were once associated with an aversive event by no longer coupling the stimulus with the aversive event. Extinction learning is supported by a network comprising the amygdala, hippocampus, and prefrontal cortex. Previous studies implicate a critical role of GABA in extinction learning, specifically the GAD65…
Methods of treating Parkinson's disease using viral vectors

DOEpatents

Bankiewicz, Krys; Cunningham, Janet

2012-11-13

Methods of delivering viral vectors, particularly recombinant AAV virions, to the central nervous system (CNS) are provided for the treatment of CNS disorders, particularly those disorders which involve the neurotransmitter dopamine. The methods entail providing rAAV virions that comprise a transgene encoding aromatic amino acid decarboxylase (AADC) and administering the virions to the brain of a mammal using a non-manual pump.
Multi-omics analysis reveals that ornithine decarboxylase contributes to erlotinib resistance in pancreatic cancer cells

PubMed Central

Song, Sang-Hoon; Lee, Naeun; Kim, Dong-Joon; Lee, Sooyeun; Jeong, Chul-Ho

2017-01-01

Molecular and metabolic alterations in cancer cells are one of the leading causes of acquired resistance to chemotherapeutics. In this study, we explored an experimental strategy to identify which of these alterations can induce erlotinib resistance in human pancreatic cancer. Using genetically matched erlotinib-sensitive (BxPC-3) and erlotinib-resistant (BxPC-3ER) pancreatic cancer cells, we conducted a multi-omics analysis of metabolomes and transcriptomes in these cells. Untargeted and targeted metabolomic analyses revealed significant changes in metabolic pathways involved in the regulation of polyamines, amino acids, and fatty acids. Further transcriptomic analysis identified that ornithine decarboxylase (ODC) and its major metabolite, putrescine, contribute to the acquisition of erlotinib resistance in BxPC-3ER cells. Notably, either pharmacological or genetic blockage of ODC was able to restore erlotinib sensitivity, and this could be rescued by treatment with exogenous putrescine in erlotinib-resistant BxPC-3ER cells. Moreover, using a panel of cancer cells we demonstrated that ODC expression levels in cancer cells are inversely correlated with sensitivity to chemotherapeutics. Taken together, our findings will begin to uncover mechanisms of acquired drug resistance and ultimately help to identify potential therapeutic markers in cancer. PMID:29190951
Heliotropium huascoense resin exudate: chemical constituents and defensive properties.

PubMed

Villarroel, L; Torres, R; Urzúa, A; Reina, M; Cabrera, R; González-Coloma, A

2001-09-01

From the resinous exudate of Heliotropium huascoense a new compound, rel-(8R,9R)-carrizaloic acid, (1) (3-[rel-(8R,9R-9-hydroxy-9,13,13-trimethyl-12-oxo-10-cyclohexenyl)methyl]-4-methoxybenzoic acid), and three known flavonoids, [3-methylgalangin, 3,7-dimethylgalangin, and (-)-alpinone] have been isolated. The structure of 1 was determined by spectral and chemical methods. Several plant defensive properties of 1 (insecticidal and antifungal) have been evaluated.
Metabolism of Oxo-Bile Acids and Characterization of Recombinant 12α-Hydroxysteroid Dehydrogenases from Bile Acid 7α-Dehydroxylating Human Gut Bacteria.

PubMed

Doden, Heidi; Sallam, Lina A; Devendran, Saravanan; Ly, Lindsey; Doden, Greta; Daniel, Steven L; Alves, João M P; Ridlon, Jason M

2018-05-15

Bile acids are important cholesterol-derived nutrient signaling hormones, synthesized in the liver, that act as detergents to solubilize dietary lipids. Bile acid 7α-dehydroxylating gut bacteria generate the toxic bile acids deoxycholic acid and lithocholic acid from host bile acids. The ability of these bacteria to remove the 7-hydroxyl group is partially dependent on 7α-hydroxysteroid dehydrogenase (HSDH) activity, which reduces 7-oxo-bile acids generated by other gut bacteria. 3α-HSDH has an important enzymatic activity in the bile acid 7α-dehydroxylation pathway. 12α-HSDH activity has been reported for the low-activity bile acid 7α-dehydroxylating bacterium Clostridium leptum ; however, this activity has not been reported for high-activity bile acid 7α-dehydroxylating bacteria, such as Clostridium scindens , Clostridium hylemonae , and Clostridium hiranonis Here, we demonstrate that these strains express bile acid 12α-HSDH. The recombinant enzymes were characterized from each species and shown to preferentially reduce 12-oxolithocholic acid to deoxycholic acid, with low activity against 12-oxochenodeoxycholic acid and reduced activity when bile acids were conjugated to taurine or glycine. Phylogenetic analysis suggests that 12α-HSDH is widespread among Firmicutes , Actinobacteria in the Coriobacteriaceae family, and human gut Archaea IMPORTANCE 12α-HSDH activity has been established in the medically important bile acid 7α-dehydroxylating bacteria C. scindens , C. hiranonis , and C. hylemonae Experiments with recombinant 12α-HSDHs from these strains are consistent with culture-based experiments that show a robust preference for 12-oxolithocholic acid over 12-oxochenodeoxycholic acid. Phylogenetic analysis identified novel members of the gut microbiome encoding 12α-HSDH. Future reengineering of 12α-HSDH enzymes to preferentially oxidize cholic acid may provide a means to industrially produce the therapeutic bile acid ursodeoxycholic acid. In addition, a cholic acid-specific 12α-HSDH expressed in the gut may be useful for the reduction in deoxycholic acid concentration, a bile acid implicated in cancers of the gastrointestinal (GI) tract. Copyright © 2018 American Society for Microbiology.
Secretion of alpha 2-plasmin inhibitor is impaired by amino acid deletion in a small region of the molecule.

PubMed

Toyota, S; Hirosawa, S; Aoki, N

1994-02-01

Alpha 2-plasmin inhibitor (alpha 2PI) deficiency Okinawa results from defective secretion of the inhibitor from the liver and appears to be a direct consequence of the deletion of Glu137 in the amino acid sequence of alpha 2PI. To examine the effects of replacing the amino acid occupying position 137 or deleting its neighboring amino acid on alpha 2PI secretion, we used oligonucleotide-directed mutagenesis of alpha 2PI cDNA to change the codon specifying Glu137 or delete a codon specifying its neighboring amino acid. The effects were determined by pulse-chase experiments and by enzyme-linked immunosorbent assay of media from transiently transfected COS-7 cells. Replacement of Glu137 with an amino acid other than Cys had little effect on alpha 2PI secretion. In contrast, deletion of an amino acid in a region spanning a sequence of less than 30 amino acids including positions 127 and 137 severely impaired the secretion. The results suggest that structural integrity of the region, rather than its component amino acids, is important for the intracellular transport and secretion of alpha 2PI.
40 CFR 721.10690 - Benzenedicarboxylic acid, polymer with substituted alkanediol, dodecanedioic acid, 1,2-ethanediol...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., alkanediol,.alpha.-hydro-.omega.-hydroxypoly[oxyalkanediyl], 1,3-isobenzofurandione, methylene diphenyl...-ethanediol, alkanedioic acid, alkanediol,.alpha.-hydro-.omega.-hydroxypoly[oxyalkanediyl], 1,3... substituted alkanediol, dodecanedioic acid, 1,2-ethanediol, alkanedioic acid, alkanediol,.alpha.-hydro-.omega...

Redirection of the Reaction Specificity of a Thermophilic Acetolactate Synthase toward Acetaldehyde Formation

PubMed Central

Cheng, Maria; Yoshiyasu, Hayato; Okano, Kenji; Ohtake, Hisao; Honda, Kohsuke

2016-01-01

Acetolactate synthase and pyruvate decarboxylase are thiamine pyrophosphate-dependent enzymes that convert pyruvate into acetolactate and acetaldehyde, respectively. Although the former are encoded in the genomes of many thermophiles and hyperthermophiles, the latter has been found only in mesophilic organisms. In this study, the reaction specificity of acetolactate synthase from Thermus thermophilus was redirected to catalyze acetaldehyde formation to develop a thermophilic pyruvate decarboxylase. Error-prone PCR and mutant library screening led to the identification of a quadruple mutant with 3.1-fold higher acetaldehyde-forming activity than the wild-type. Site-directed mutagenesis experiments revealed that the increased activity of the mutant was due to H474R amino acid substitution, which likely generated two new hydrogen bonds near the thiamine pyrophosphate-binding site. These hydrogen bonds might result in the better accessibility of H+ to the substrate-cofactor-enzyme intermediate and a shift in the reaction specificity of the enzyme. PMID:26731734
Experiment K-7-21: Effect of Microgravity on 1: Metabolic Enzymes of Type 1 and Type 2 Muscle Fibers, and on 2: Metabolic Enzymes, Neurotransmitter Amino Acids, and Neurotransmitter Associated Enzymes in Selected Regions of the Central Nervous System. Part 2; The Distribution of Selected Enzymes and Amino Acids in the Hippocampal Formation

NASA Technical Reports Server (NTRS)

Lowry, O. H.; Krasnov, I.; Ilyina-Kakueva, E. I.; Nemeth, P. M.; McDougal, D. B., Jr.; Choksi, R.; Carter, J. G.; Chi, M. M. Y.; Manchester, J. K.; Pusateri, M. E.

1994-01-01

Six key metabolic enzymes plus glutaminase and glutamate decarboxylase, as well as glutamate, aspartate and GABA, were measured in 11 regions of the hippocampal formation of synchronous, flight and tail suspension rats. Major differences were observed in the normal distribution patterns of each enzyme and amino acid, but no substantive effects of either microgravity or tail suspension on these patterns were clearly demonstrated.
Submerged fermentation of Lactobacillus rhamnosus YS9 for γ-aminobutyric acid (GABA) production

PubMed Central

Lin, Qian

2013-01-01

γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in central nervous system, and its application in drugs and functional foods has attracted great attention. To enhance production of γ-aminobutyric acid, Lactobacillus rhamnosus YS9, a strain isolated from Chinese traditional fermented food pickled vegetable, was grown under submerged fermentation. Its cultivation conditions were investigated. When culture pH condition was adjusted to the optimal pH of glutamate decarboxylase activity, culture of Lb. rhamnosus YS9 in medium supplemented with 200 mM of monosodium glutamate and 200 μM of pyridoxal phosphate (PLP), produced 187 mM of GABA. PMID:24159304
alpha-Ketoglutarate application in hemodialysis patients improves amino acid metabolism.

PubMed

Riedel, E; Nündel, M; Hampl, H

1996-01-01

In hemodialysis patients, free amino acids and alpha-ketoacids in plasma were determined by fluorescence HPLC to assess the effect of alpha-ketoglutarate administration in combination with the phosphate binder calcium carbonate on the amino acid metabolism. During 1 year of therapy in parallel to inorganic phosphate, urea in plasma decreased significantly, histidine, arginine and proline as well as branched chain alpha-ketoacids, in particular alpha-ketoisocaproate, a regulator of protein metabolism, increased. Thus, administration of alpha-ketoglutarate with calcium carbonate effectively improves amino acid metabolism in hemodialysis patients as it decreases hyperphosphatemia.
Crystal structure of homoisocitrate dehydrogenase from Schizosaccharomyces pombe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bulfer, Stacie L.; Hendershot, Jenna M.; Trievel, Raymond C.

Lysine biosynthesis in fungi, euglena, and certain archaebacteria occurs through the {alpha}-aminoadipate pathway. Enzymes in the first steps of this pathway have been proposed as potential targets for the development of antifungal therapies, as they are absent in animals but are conserved in several pathogenic fungi species, including Candida, Cryptococcus, and Aspergillus. One potential antifungal target in the {alpha}-aminoadipate pathway is the third enzyme in the pathway, homoisocitrate dehydrogenase (HICDH), which catalyzes the divalent metal-dependent conversion of homoisocitrate to 2-oxoadipate (2-OA) using nicotinamide adenine dinucleotide (NAD{sup +}) as a cofactor. HICDH belogns to a family of {beta}-hydroxyacid oxidative decarboxylases thatmore » includes malate dehydrogenase, tartrate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase (ICDH), and 3-isopropylmalte dehydrogenase (IPMDH). ICDH and IPMDH are well-characterized enzymes that catalyze the decarboxylation of isocitrate to yield 2-oxoglutarate (2-OG) in the citric acid cycle and the conversion of 3-isopropylmalate to 2-oxoisovalerate in the leucine biosynthetic pathway, respectively. Recent structural and biochemical studies of HICDH reveal that this enzyme shares sequence, structural, and mechanistic homology with ICDH and IPMDH. To date, the only published structures of HICDH are from the archaebacteria Thermus thermophilus (TtHICDH). Fungal HICDHs diverge from TtHICDH in several aspects, including their thermal stability, oligomerization state, and substrate specificity, thus warranting further characterization. To gain insights into these differences, they determined crystal structures of a fungal Schizosaccharomyces pombe HICDH (SpHICDH) as an apoenzyme and as a binary complex with additive tripeptide glycyl-glycyl-glycine (GGG) to 1.55 {angstrom} and 1.85 {angstrom} resolution, respectively. Finally, a comparison of the SpHICDH and TtHICDH structures reveal differences in their active sites that help explain the variations in their respective substrate specificities.« less
Isolation of Chromanone and Isobenzofuran Derivatives from a Fungicolous Isolate of Epiccocum purpurascens

USDA-ARS?s Scientific Manuscript database

Chemical studies of an organic extract of Epicoccum purpurascens NRRL 37031, isolated from a wood decay fungus in Florida, led to the isolation of two new metabolites, 7-methoxy-4-oxo-chroman-5-carboxylic acid methyl ester (1) and 1,3-dihydro-5-methoxy-7-methylisobenzofuran (2). Two known isobenzof...
Acetylsalicylic acid regulates MMP-2 activity and inhibits colorectal invasion of murine B16F0 melanoma cells in C57BL/6J mice: effects of prostaglandin F(2)alpha.

PubMed

Tsai, Chin-Shaw Stella; Luo, Shue-Fen; Ning, Chung-Chu; Lin, Chien-Liang; Jiang, Ming-Chung; Liao, Ching-Fong

2009-08-01

Epidemiological studies indicate that acetylsalicylic acid may reduce the risk of mortality due to colon cancers. Metastasis is the major cause of cancer death. Matrix metalloproteinases (MMPs) play important roles in tumor invasion regulation, and prostaglandin F(2)alpha (PGF(2)alpha) is a key stimulator of MMP production. Thus, we investigated whether acetylsalicylic acid regulated MMP activity and the invasion of cancer cells and whether PGF(2)alpha attenuated acetylsalicylic acid-inhibited invasion of cancer cells. Gelatin-based zymography assays showed that acetylsalicylic acid inhibited the MMP-2 activity of B16F0 melanoma cells. Matrigel-based chemoinvasion assays showed that acetylsalicylic acid inhibited the invasion of B16F0 cells. Acetylsalicylic acid can inhibit PGF(2)alpha synthesis and PGF(2)alpha is a key stimulator of MMP-2 production. Our data showed that PGF(2)alpha treatment attenuated the acetylsalicylic acid-inhibited invasion of B16F0 cells. In animal experiments, acetylsalicylic acid reduced colorectal metastasis of B16F0 cells in C57BL/6J mice by 44%. Our results suggest that PGF(2)alpha is a therapeutic target for metastasis inhibition and acetylsalicylic acid may possess anti-metastasis ability.
Midrange affinity fluorescent Zn(II) sensors of the Zinpyr family: syntheses, characterization, and biological imaging applications.

PubMed

Nolan, Elizabeth M; Jaworski, Jacek; Racine, Maryann E; Sheng, Morgan; Lippard, Stephen J

2006-11-27

The syntheses and photophysical characterization of ZP9, 2-{2-chloro-6-hydroxy-3-oxo-5-[(2-{[pyridin-2-ylmethyl-(1H-pyrrol-2-ylmethyl)amino]methyl}phenylamino)methyl]-3H-xanthen-9-yl}benzoic acid, and ZP10, 2-{2-chloro-6-hydroxy-5-[(2-{[(1-methyl-1H-pyrrol-2-ylmethyl)pyridin-2-ylmethylamino]methyl}phenylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid, two asymmetrically derivatized fluorescein-based dyes, are described. These sensors each contain an aniline-based ligand moiety functionalized with a pyridyl-amine-pyrrole group and have dissociation constants for Zn(II) in the sub-micromolar (ZP9) and low-micromolar (ZP10) range, which we define as "midrange". They give approximately 12- (ZP9) and approximately 7-fold (ZP10) fluorescence turn-on immediately following Zn(II) addition at neutral pH and exhibit improved selectivity for Zn(II) compared to the di-(2-picolyl)amine-based Zinpyr (ZP) sensors. Confocal microscopy studies indicate that such asymmetrical fluorescein-based probes are cell permeable and Zn(II) responsive in vivo.
Midrange Affinity Fluorescent Zn(II) Sensors of the Zinpyr Family: Syntheses, Characterization, and Biological Imaging Applications

PubMed Central

Nolan, Elizabeth M.; Jaworski, Jacek; Racine, Maryann E.; Sheng, Morgan; Lippard, Stephen J.

2006-01-01

The syntheses and photophysical characterization of ZP9, 2-{2-chloro-6-hydroxy-3-oxo-5-[(2-{[pyridin-2-ylmethyl-(1H-pyrrol-2-ylmethyl)amino]methyl}phenylamino)methyl]-3H-xanthen-9-yl}benzoic acid, and ZP10, 2-{2-chloro-6-hydroxy-5-[(2-{[(1-methyl-1H-pyrrol-2-ylmethyl)pyridin-2-ylmethylamino]methyl}phenylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid, two asymmetrically derivatized fluorescein-based dyes, are described. These sensors each contain an aniline-based ligand moiety functionalized with a pyridyl-amine-pyrrole group and have dissociation constants for Zn(II) in the sub-micromolar (ZP9) and low-micromolar (ZP10) range, which we define as “midrange”. They give ~12- (ZP9) and ~7-fold (ZP10) fluorescence turn-on immediately following Zn(II) addition at neutral pH and exhibit improved selectivity for Zn(II) compared to the di-(2-picolyl)amine-based Zinpyr (ZP) sensors. Confocal microscopy studies indicate that such asymmetrical fluorescein-based probes are cell permeable and Zn(II) responsive in vivo. PMID:17112271
Management of postharvest grape withering to optimise the aroma of the final wine: A case study on Amarone.

PubMed

Bellincontro, A; Matarese, F; D'Onofrio, C; Accordini, D; Tosi, E; Mencarelli, F

2016-12-15

Amarone wine is different from regular dry wine due to the postharvest withering of Corvina, Corvinone and Rondinella grapes. Grapes were withered in a commercial facility with variability in terms of temperature and relative humidity (R.H.). Sugar content reached 230-240gL(-1) and 280gL(-1) at 20% and 30% mass loss, respectively. Most of VOCs (volatile organic compounds) decreased during withering but few VOCs increased during withering and we considered as markers; in Corvinone they were methylhexanoate, dimethylsuccinate, nerol, nonanoic acid, and benzyl alcohol; in Corvina, benzyl alcohol, isoamyl alcohol, 1-hexanol, p-cymen-8-ol, 2,3 pinanediol, 3-oxo-ionol and 3-methyl-1-pentanol, coumaran and damascenone; in Rondinella, hexanol, nonanoic acid, methyl vanillate, damascenone, 3-oxo-ionol, eugenol, p-cymen-8-ol, 2,3 pinanediol, coumaran and raspberry keton. Olfactive descriptors of the wines and the potential aroma of the combination of Corvina wine with the wines of the other two varieties at different percentages of mass loss are reported. Copyright © 2016 Elsevier Ltd. All rights reserved.
Discovery of novel 2-[(4-hydroxy-6-oxo-2,3-dihydro-1H-pyridine-5-carbonyl)amino]acetic acid derivatives as HIF prolyl hydroxylase inhibitors for treatment of renal anemia.

PubMed

Hamada, Makoto; Takayama, Tetsuo; Shibata, Tsuyoshi; Hiratate, Akira; Takahashi, Masato; Yashiro, Miyoko; Takayama, Noriko; Okumura-Kitajima, Lisa; Koretsune, Hiroko; Kajiyama, Hiromitsu; Naruse, Takumi; Kato, Sota; Takano, Hiroki; Kakinuma, Hiroyuki

2018-06-01

Prolyl hydroxylase domain-containing protein (PHD) inhibitors are useful as orally administered agents for the treatment of renal anemia. Based on the common structures of known PHD inhibitors, we found novel PHD inhibitor 1 with a 2-[(4-hydroxy-6-oxo-2,3-dihydro-1H-pyridine-5-carbonyl)amino]acetic acid motif. The PHD2-inhibitory activity, lipophilicity (CLogP), and PK profiles (hepatocyte metabolism, protein binding, and/or elimination half-life) of this inhibitor were used as the evaluation index to optimize the structure and eventually discovered clinical candidate 42 as the suitable compound. Compound 42 was demonstrated to promote the production of erythropoietin (EPO) following oral administration in mice and rats. The predicted half-life of this compound in humans was 1.3-5.6 h, therefore, this drug may be expected to administer once daily with few adverse effects caused by excessive EPO production. Copyright © 2018 Elsevier Ltd. All rights reserved.
Antiamnesic Effect of Broccoli (Brassica oleracea var. italica) Leaves on Amyloid Beta (Aβ)1-42-Induced Learning and Memory Impairment.

PubMed

Park, Seon Kyeong; Ha, Jeong Su; Kim, Jong Min; Kang, Jin Yong; Lee, Du Sang; Guo, Tian Jiao; Lee, Uk; Kim, Dae-Ok; Heo, Ho Jin

2016-05-04

To examine the antiamnesic effects of broccoli (Brassica oleracea var. italica) leaves, we performed in vitro and in vivo tests on amyloid beta (Aβ)-induced neurotoxicity. The chloroform fraction from broccoli leaves (CBL) showed a remarkable neuronal cell-protective effect and an inhibition against acetylcholinesterase (AChE). The ameliorating effect of CBL on Aβ1-42-induced learning and memory impairment was evaluated by Y-maze, passive avoidance, and Morris water maze tests. The results indicated improving cognitive function in the CBL group. After the behavioral tests, antioxidant effects were detected by superoxide dismutase (SOD), oxidized glutathione (GSH)/total GSH, and malondialdehyde (MDA) assays, and inhibition against AChE was also presented in the brain. Finally, oxo-dihydroxy-octadecenoic acid (oxo-DHODE) and trihydroxy-octadecenoic acid (THODE) as main compounds were identified by quadrupole time-of-flight ultraperformance liquid chromatography (Q-TOF UPLC-MS) analysis. Therefore, our studies suggest that CBL could be used as a natural resource for ameliorating Aβ1-42-induced learning and memory impairment.
Metabolism and disposition of a novel antineoplastic JS-38 (Benzamide, N-[4-(2,4-dimethoxyphenyl)-4,5-dihydro-5-oxo-1,2-dithiolo[4,3-b]pyrrol-6-yl]-3,5-bis (trifluoromethyl)-(9Cl)) in rats.

PubMed

Zhang, Hong; Liu, Quanhai; Fan, Tingting; Fang, Yu; Li, Ying; Wang, Guoping

2012-03-01

The metabolism and catabolism of a novel antineoplastic (ID code JS-38),Benzamide, N-[4-(2,4-dimethoxyphenyl)-4,5-dihydro-5-oxo-1,2-dithiolo[4,3-b]pyrrol-6-yl]-3,5-bis (trifluoromethyl)-(9Cl), were investigated in Wistar rats (3 female, 3 male). LC/UV, LC/MS, LC/MS/MS, NMR and acid hydrolysis methods showed that the metabolic process of JS-38 consists of a series of acetylation and glucoronation that form a metabolic product with a unique pharmacologic property of accelerating bone-marrow cell formation, and also showed a novel metabolic pathway of being acetylated and glucuronated in series.
Pharmacologically relevant receptor binding characteristics and 5alpha-reductase inhibitory activity of free Fatty acids contained in saw palmetto extract.

PubMed

Abe, Masayuki; Ito, Yoshihiko; Oyunzul, Luvsandorj; Oki-Fujino, Tomomi; Yamada, Shizuo

2009-04-01

Saw palmetto extract (SPE), used widely for the treatment of benign prostatic hyperplasia (BPH) has been shown to bind alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine (1,4-DHP) calcium channel antagonist receptors. Major constituents of SPE are lauric acid, oleic acid, myristic acid, palmitic acid and linoleic acid. The aim of this study was to investigate binding affinities of these fatty acids for pharmacologically relevant (alpha(1)-adrenergic, muscarinic and 1,4-DHP) receptors. The fatty acids inhibited specific [(3)H]prazosin binding in rat brain in a concentration-dependent manner with IC(50) values of 23.8 to 136 microg/ml, and specific (+)-[(3)H]PN 200-110 binding with IC(50) values of 24.5 to 79.5 microg/ml. Also, lauric acid, oleic acid, myristic acid and linoleic acid inhibited specific [(3)H]N-methylscopolamine ([(3)H]NMS) binding in rat brain with IC(50) values of 56.4 to 169 microg/ml. Palmitic acid had no effect on specific [(3)H]NMS binding. The affinity of oleic acid, myristic acid and linoleic acid for each receptor was greater than the affinity of SPE. Scatchard analysis revealed that oleic acid and lauric acid caused a significant decrease in the maximal number of binding sites (B(max)) for [(3)H]prazosin, [(3)H]NMS and (+)-[(3)H]PN 200-110. The results suggest that lauric acid and oleic acid bind noncompetitively to alpha(1)-adrenergic, muscarinic and 1,4-DHP calcium channel antagonist receptors. We developed a novel and convenient method of determining 5alpha-reductase activity using LC/MS. With this method, SPE was shown to inhibit 5alpha-reductase activity in rat liver with an IC(50) of 101 microg/ml. Similarly, all the fatty acids except palmitic acid inhibited 5alpha-reductase activity, with IC(50) values of 42.1 to 67.6 microg/ml. In conclusion, lauric acid, oleic acid, myristic acid, and linoleic acid, major constituents of SPE, exerted binding activities of alpha(1)-adrenergic, muscarinic and 1,4-DHP receptors and inhibited 5alpha-reductase activity.
Acid and Base Stress and Transcriptomic Responses in Bacillus subtilis▿†

PubMed Central

Wilks, Jessica C.; Kitko, Ryan D.; Cleeton, Sarah H.; Lee, Grace E.; Ugwu, Chinagozi S.; Jones, Brian D.; BonDurant, Sandra S.; Slonczewski, Joan L.

2009-01-01

Acid and base environmental stress responses were investigated in Bacillus subtilis. B. subtilis AG174 cultures in buffered potassium-modified Luria broth were switched from pH 8.5 to pH 6.0 and recovered growth rapidly, whereas cultures switched from pH 6.0 to pH 8.5 showed a long lag time. Log-phase cultures at pH 6.0 survived 60 to 100% at pH 4.5, whereas cells grown at pH 7.0 survived <15%. Cells grown at pH 9.0 survived 40 to 100% at pH 10, whereas cells grown at pH 7.0 survived <5%. Thus, growth in a moderate acid or base induced adaptation to a more extreme acid or base, respectively. Expression indices from Affymetrix chip hybridization were obtained for 4,095 protein-encoding open reading frames of B. subtilis grown at external pH 6, pH 7, and pH 9. Growth at pH 6 upregulated acetoin production (alsDS), dehydrogenases (adhA, ald, fdhD, and gabD), and decarboxylases (psd and speA). Acid upregulated malate metabolism (maeN), metal export (czcDO and cadA), oxidative stress (catalase katA; OYE family namA), and the SigX extracytoplasmic stress regulon. Growth at pH 9 upregulated arginine catabolism (roc), which generates organic acids, glutamate synthase (gltAB), polyamine acetylation and transport (blt), the K+/H+ antiporter (yhaTU), and cytochrome oxidoreductases (cyd, ctaACE, and qcrC). The SigH, SigL, and SigW regulons were upregulated at high pH. Overall, greater genetic adaptation was seen at pH 9 than at pH 6, which may explain the lag time required for growth shift to high pH. Low external pH favored dehydrogenases and decarboxylases that may consume acids and generate basic amines, whereas high external pH favored catabolism-generating acids. PMID:19114526
Acid and base stress and transcriptomic responses in Bacillus subtilis.

PubMed

Wilks, Jessica C; Kitko, Ryan D; Cleeton, Sarah H; Lee, Grace E; Ugwu, Chinagozi S; Jones, Brian D; BonDurant, Sandra S; Slonczewski, Joan L

2009-02-01

Acid and base environmental stress responses were investigated in Bacillus subtilis. B. subtilis AG174 cultures in buffered potassium-modified Luria broth were switched from pH 8.5 to pH 6.0 and recovered growth rapidly, whereas cultures switched from pH 6.0 to pH 8.5 showed a long lag time. Log-phase cultures at pH 6.0 survived 60 to 100% at pH 4.5, whereas cells grown at pH 7.0 survived <15%. Cells grown at pH 9.0 survived 40 to 100% at pH 10, whereas cells grown at pH 7.0 survived <5%. Thus, growth in a moderate acid or base induced adaptation to a more extreme acid or base, respectively. Expression indices from Affymetrix chip hybridization were obtained for 4,095 protein-encoding open reading frames of B. subtilis grown at external pH 6, pH 7, and pH 9. Growth at pH 6 upregulated acetoin production (alsDS), dehydrogenases (adhA, ald, fdhD, and gabD), and decarboxylases (psd and speA). Acid upregulated malate metabolism (maeN), metal export (czcDO and cadA), oxidative stress (catalase katA; OYE family namA), and the SigX extracytoplasmic stress regulon. Growth at pH 9 upregulated arginine catabolism (roc), which generates organic acids, glutamate synthase (gltAB), polyamine acetylation and transport (blt), the K(+)/H(+) antiporter (yhaTU), and cytochrome oxidoreductases (cyd, ctaACE, and qcrC). The SigH, SigL, and SigW regulons were upregulated at high pH. Overall, greater genetic adaptation was seen at pH 9 than at pH 6, which may explain the lag time required for growth shift to high pH. Low external pH favored dehydrogenases and decarboxylases that may consume acids and generate basic amines, whereas high external pH favored catabolism-generating acids.
Effect of inhibitors of polyamine biosynthesis on gibberellin-induced internode growth in light-grown dwarf peas

NASA Technical Reports Server (NTRS)

Kaur-Sawhney, R.; Dai, Y. R.; Galston, A. W.

1986-01-01

When gibberellic acid (GA3) is sprayed on 9-day-old light-brown dwarf Progress pea (Pisum sativum) seedlings, arginine decarboxylase (ADC; EC 4.1.1.9) activity increases within 3 h and peaks at about 9 h after GA3 application. This is followed by a second lower peak at about 30 h; both peaks were higher than the corresponding peaks in the controls. In contrast, no appreciable effect of GA3 on internode length was observed until about 12 h, after which time a dramatic increase in growth rate occurred and persisted for about 12 h. Specific (DL-alpha-difluoromethylarginine) and non-specific (D-arginine and L-canavanine) inhibitors of ADC strongly inhibited ADC activity and to a lesser extent internode growth. The inhibition was reversed only slightly by the addition of polyamines. Actinomycin D and cycloheximide inhibited the rise in ADC activity induced by GA3. The half-life of the enzyme was increased by GA3 treatment. The results suggest that part of the GA3-induced increase in internode growth may result from enhanced polyamine biosynthesis through the ADC pathway. Furthermore, the GA3 induced increase in ADC activity probably requires de novo synthesis of both RNA and protein.
Influence of dietary long-chain n-3 fatty acids from menhaden fish oil on plasma concentrations of alpha-tocopherol in geriatric beagles.

PubMed

Hall, Jean A; Tooley, Katie A; Gradin, Joseph L; Jewell, Dennis E; Wander, Rosemary C

2002-01-01

To determine effects of dietary n-3 fatty acids from Menhaden fish oil on plasma alpha-tocopherol concentrations in Beagles. 32 female Beagles. For 82 days, dogs were fed diets that contained 1 of 2 ratios of n-6:n-3 fatty acids (40:1 [low n-3] and 1.4:1 [high n-3]) and 1 of 3 concentrations of all-rac-alpha-tocopheryl acetate (low, 17 mg/kg of diet; medium, 101 mg/kg; and high, 447 mg/kg) in a 2 X 3 factorial study. Diets high in n-3 fatty acids significantly increased total content of n-3 fatty acids in plasma (17.0 g/100 g of fatty acids), compared with low n-3 diets (2.02 g/100 g of fatty acids). Mean +/- SEM plasma concentration of cholesterol was significantly lower in dogs consuming high n-3 diets (4.59 +/- 0.48 mmol/L), compared with dogs consuming low n-3 diets (5.71 +/- 0.48 mmol/L). A significant interaction existed between the ratio for n-6 and n-3 fatty acids and amount of alpha-tocopheryl acetate in the diet (plasma alpha-tocopherol concentration expressed on a molar basis), because the plasma concentration of alpha-toco-pherol was higher in dogs consuming low n-3 diets, compared with those consuming high n-3 diets, at the 2 higher amounts of dietary alpha-tocopheryl acetate. Plasma alpha-tocopherol concentration expressed relative to total lipid content did not reveal effects of dietary n-3 fatty acids on concentration of alpha-tocopherol. Plasma alpha-tocopherol concentration is not dependent on dietary ratio of n-6 and n-3 fatty acids when alpha-tocopherol concentration is expressed relative to the total lipid content of plasma.
Triterpenoids from the roots of Rubus parvifolius.

PubMed

Zhang, Xu; Zhu, Zhi-Xiang; Wang, Juan; Yang, Wan-Qing; Su, Cong; Li, Jun; Zhang, Yuan; Zheng, Jiao; Shi, She-Po; Tu, Peng-Fei

2016-05-01

Two new oleanane-type triterpenoids, parvifolactone A (1) and rubuside P (2), together with 11 known triterpenoids, fupenzic acid (3), 18,19-seco,2α,3α-dihydroxyl-19-oxo-urs-11,13(18)-dien-28-oic acid (4), euscaphic acid (5), maslinic acid (6), 1β- hydroxyeuscaphic acid (7), 2α,3α,19α,23-tetrahydroxyolean-12-en-28-oic acid (8), 2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid (9), glucosyl pinfaensate (10), rubuside J (11), 2α,3α,19α,23-tetrahydroxyurs-12-en-24,28-dioic acid (12), and 2α,3β,19α- trihydroxyurs-12-en-23,28-dioic acid (13), were isolated from the roots of Rubus parvifolius. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.
Long-Lived Photoinduced Charge Separation in a Trinuclear Iron-μ 3 -oxo-based Metal–Organic Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanna, Lauren; Kucheryavy, Pavel; Liu, Cunming

2017-06-14

The presence of long-lived charge-separated excited states in metal-organic frameworks (MOFs) can enhance their photocatalytic activity by decreasing the probability that photogenerated electrons and holes recombine before accessing adsorbed reactants. Detecting these charge separated states via optical transient absorption, however, can be challenging when they lack definitive optical signatures. Here, we investigate the long-lived excited state of a MOF with such vague optical properties, MIL-100(Fe), comprised of Fe3-μ3-oxo clusters and trimesic acid linkers using Fe K-edge X-ray transient absorption (XTA) spectroscopy, to unambiguously determine its ligand-to-metal charge transfer character. Spectra measured at time delays up to 3.6 μs confirm themore » long lived nature of the charge separated excited state. Several trinuclear iron μ3- oxo carboxylate complexes, which model the trinuclear cores of the MOF structure, are measured for comparison using both steady state XAS and XTA to further support this assignment and corresponding decay time. The MOF is prepared as a colloidal nanoparticle suspension for these measurements so both its fabrication and particle size analysis are presented, as well.« less

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