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Sample records for dimethyl-substituted malonic succinic

  1. Evaporation of methyl- and dimethyl-substituted malonic, succinic, glutaric and adipic acid particles at ambient temperatures

    DEFF Research Database (Denmark)

    Mønster, Jacob Garbrecht; Rosenørn, Thomas; Svenningsson, Birgitta

    2004-01-01

    Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid......Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid...

  2. Substitution reactions of [Pd(bipy)(malonate)] explored with a ...

    Indian Academy of Sciences (India)

    −3. NaClO4. Table 1. Metal-Ligand ratios and structures of the product complexes. Metal:Ligand. Ligand. Structure ratio. Product complex. L1 Thioglycolic acid. HS ..... O. Scheme 1. Plausible mechanistic pathway. molecules substitute the bidentate malonate in a consec- utive fashion. Among the three sulphur donor ligands.

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

    International Nuclear Information System (INIS)

    Mayani, Mbutyabo

    1983-01-01

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

  4. Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

    Science.gov (United States)

    Ping-Ping Xin; Yao-Bing Huang; Chung-Yun Hse; Huai N. Cheng; Chaobo Huang; Hui. Pan

    2017-01-01

    Homogeneous modification of cellulose with succinic anhydride was performed using tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU), TBAA dosage, reaction temperature, and reaction time were investigated. The highest degree of substitution (DS)...

  5. Gold-nanoparticle-based catalysts for the oxidative esterification of 1,4-butanediol into dimethyl succinate.

    Science.gov (United States)

    Brett, Gemma L; Miedziak, Peter J; He, Qian; Knight, David W; Edwards, Jennifer K; Taylor, Stuart H; Kiely, Christopher J; Hutchings, Graham J

    2013-10-01

    The oxidation of 1,4-butanediol and butyrolactone have been investigated by using supported gold, palladium and gold-palladium nanoparticles. The products of such reactions are valuable chemical intermediates and, for example, can present a viable pathway for the sustainable production of polymers. If both gold and palladium were present, a significant synergistic effect on the selective formation of dimethyl succinate was observed. The support played a significant role in the reaction, with magnesium hydroxide leading to the highest yield of dimethyl succinate. Based on structural characterisation of the fresh and used catalysts, it was determined that small gold-palladium nanoalloys supported on a basic Mg(OH)2 support provided the best catalysts for this reaction. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Enhancement of malate-production and increase in sensitivity to dimethyl succinate by mutation of the VID24 gene in Saccharomyces cerevisiae.

    Science.gov (United States)

    Negoro, Hiroaki; Kotaka, Atsushi; Matsumura, Kengo; Tsutsumi, Hiroko; Hata, Yoji

    2016-06-01

    Malate in sake (a Japanese alcoholic beverage) is an important component for taste that is produced by yeasts during alcoholic fermentation. To date, many researchers have developed methods for breeding high-malate-producing yeasts; however, genes responsible for the high-acidity phenotype are not known. We determined the mutated gene involved in high malate production in yeast, isolated as a sensitive mutant to dimethyl succinate. In the comparative whole genome analysis between high-malate-producing strain and its parent strain, one of the non-synonymous substitutions was identified in the VID24 gene. The mutation of VID24 resulted in enhancement of malate-productivity and sensitivity to dimethyl succinate. The mutation appeared to lead to a deficiency in Vid24p function. Furthermore, disruption of cytoplasmic malate dehydrogenase (Mdh2p) gene in the VID24 mutant inhibited the high-malate-producing phenotype. Vid24p is known as a component of the multisubunit ubiquitin ligase and participates in the degradation of gluconeogenic enzymes such as Mdh2p. We suggest that the enhancement of malate-productivity results from an accumulation of Mdh2p due to the loss of Vid24p function. These findings propose a novel mechanism for the regulation of organic acid production in yeast cells by the component of ubiquitin ligase, Vid24p. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Noval 1-substituted-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazole derivatives: Synthesis and pharmacological activity

    Directory of Open Access Journals (Sweden)

    Sabir Hussain

    2015-05-01

    Full Text Available Several-1-carbothioamide-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 2a–d, 1-(pyridine-4-ylcarbonyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 3a–d, 1-(5-chloro-6-fluoro-1,3-benzothiazole-2-ylthiocarbamoyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 4a–d and 1-[(1,2,4-triazole-4-yl carbothioamide]-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 5a–d were synthesized. The structures of the newly synthesized compounds were supported by IR, 1H NMR and mass spectral data. These compounds were investigated for their, anti-inflammatory, analgesic, ulcerogenic, lipid peroxidation, antibacterial and antifungal activities. Some of the synthesized compounds showed potent anti-inflammatory activity along with minimal ulcerogenic effect and lipid peroxidation, compared to ibuprofen and flurbiprofen. Some of the tested compounds also showed moderate antimicrobial activity against tested bacterial and fungal strains.

  8. Thermodynamics of U(VI) complexation by succinate at variable temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, Neetika [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tomar, B.S., E-mail: bstomar@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Manchanda, V.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2011-07-15

    Research highlights: > lg {beta} and {Delta}H{sub C} for U(VI)-succinate determined at variable temperatures. > Increase in lg {beta} with temperature well explained by Born equation. > {Delta}S{sub C} plays the dominant role in variation of {Delta}G{sub C} with temperature. > {Delta}H{sub C} for U(VI)-succinate increases linearly with temperature. > {Delta}C{sub P} of U(VI)-succinate is higher than that of oxalate and malonate complexes. - Abstract: Complexation of U(VI) by succinate has been studied at various temperatures in the range of (298 to 338) K by potentiometry and isothermal titration calorimetry at constant ionic strength (1.0 M). The potentiometric titrations revealed the formation of 1:1 uranyl succinate complex in the pH range of 1.5 to 4.5. The stability constant of uranyl succinate complex was found to increase with temperature. Similar trend was observed in the case of enthalpy of complex formation. However, the increase in entropy with temperature over-compensated the increase in enthalpy, thereby favouring the complexation reaction at higher temperatures. The linear increase of enthalpy of complexation with temperature indicates constancy of the change in heat capacity during complexation. The temperature dependence of stability constant data was well explained with the help of Born equation for electrostatic interaction between the metal ion and the ligand. The data have been compared with those for uranyl complexes with malonate and oxalate to study the effect of ligand size and hydrophobicity on the temperature dependence of thermodynamic quantities.

  9. The sonochemical arylation of malonic esters mediated by manganese triacetate.

    Science.gov (United States)

    Meciarova, M; Toma, S; Luche, J L

    2001-04-01

    The intermolecular arylation of malonate esters in acetic acid solution in the presence of manganese(III) triacetate is known to proceed via an Electron Transfer mechanism. Under sonication, this reaction undergoes only minor changes. In contrast, the intramolecular reaction of dimethyl alpha-(3-phenylpropyl)malonate provides a new case of sonochemical switching, with the formation of compounds 7-9, while conventional thermal conditions generate only the bicyclic compound 6. Reactions using the more powerful oxidant, cerium ammonium nitrate are governed by the formation of the nitrate ester 11. Compounds 7-9 are isolated in yields lower than with MnTA, and in proportions depending on the conditions, thermal or sonochemical.

  10. Preparation of deuterated succinic acids

    Energy Technology Data Exchange (ETDEWEB)

    Tashiro, Masashi; Tsuzuki, Hirohisa; Goto, Hideyuki; Ogasahara, Shoji; Mataka, Shuntaro (Kyushu Univ., Fukuoka (Japan)); Isobe, Shin-ichiro; Yonemitsu, Tadashi (Kyushu Sangyo Univ., Fukuoka (Japan). Dept. of Industrial Chemistry)

    1991-04-01

    Succinic (2,3-{sup 2}H{sub 2})- and (2,2,3,3-{sup 2}H{sub 4})-acids were prepared from maleic anhydride and dimethyl fumarate, and acetylene dicarboxylic acid and its dimethyl ester by treatment with Cu-Al and Ni-Al alloys in 10% NaOD-D{sub 2}0 in 95% to 100% isotopic purity. The succinic {sup 2}H{sub 4} acid having high isotopic purity was also obtained on the hydrolysis of 1,2-ethanedinitrile with alkaline deuterium oxide. Based on the {sup 1}H({sup 2}H) spectra analysis of N-(o-biphenyl)(2,3-{sup 2}H{sub 2})succinimide, it was elucidated that the Raney alloy reduction with alkaline deuterium oxide proceeds stepwise. (author).

  11. Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

    Science.gov (United States)

    Homogeneous modification of cellulose with succinic anhydride was performed in tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU) and TBAA dosage were investigated as paramete...

  12. 1,2,3,4-Tetrahydroisoquinoline protects terminals of dopaminergic neurons in the striatum against the malonate-induced neurotoxicity.

    Science.gov (United States)

    Lorenc-Koci, Elzbieta; Gołembiowska, Krystyna; Wardas, Jadwiga

    2005-07-27

    Malonate, a reversible inhibitor of the mitochondrial enzyme succinate dehydrogenase, is frequently used as a model neurotoxin to produce lesion of the nigrostriatal dopaminergic system in animals due to particular sensitivity of dopamine neurons to mild energy impairment. This model of neurotoxicity was applied in our study to explore neuroprotective potential of 1,2,3,4-tetrahydroisoquinoline (TIQ), an endo- and exogenous substance whose function in the mammalian brain, despite extensive studies, has not been elucidated so far. Injection of malonate at a dose of 3 mumol unilaterally into the rat left medial forebrain bundle resulted in the 54% decrease in dopamine (DA) concentration in the ipsilateral striatum and, depending on the examined striatum regions, caused 24-44% reduction in [3H]GBR12,935 binding to the dopamine transporter (DAT). TIQ (50 mg/kg i.p.) administered 4 h before malonate infusion and next once daily for successive 7 days prevented both these effects of malonate. Such TIQ treatment restored DA content and DAT binding almost to the control level. The results of the present study indicate that TIQ may act as a neuroprotective agent in the rat brain. An inhibition of the enzymatic activities of monoamine oxidase and gamma-glutamyl transpeptidase as well as an increase in the striatal levels of glutathione and nitric oxide found after TIQ administration and reported in our earlier studies are considered to be potential factors that may be involved in the TIQ-mediated protection of dopamine terminals from malonate toxicity.

  13. Influence of salicylic and succinic acids on antioxidant enzymes activity, heat resistance and productivity of Panicum miliaceum L.

    Directory of Open Access Journals (Sweden)

    Miroshnichenko N.N.

    2011-05-01

    Full Text Available The influence of treatment of millet (Panicum miliaceum L. seeds with the solutions of salicylic and succinic acids on the heat resistance of plantlets and activity of antioxidant enzymes – superoxide dismutase (SOD, catalase and peroxidase – in them have been investigated. In the micro-field experiment the influence of these acids on the millet yield was estimated. The action of salicylic (10 μM and succinic (1 mM acids caused the increase of plantlets resistance to the damaging heating that expressed in the rise of relative quantity of survived plantlets in 5 days after heating at the temperature of 47°С and in the reduced content of lipid peroxidation product malonic dialdehyde during the poststress period. The increase of activity of SOD, catalase and peroxidase took place in millet plantlets under the influence of salicylic and succinic acids. The increase of productivity of millet grain under the action of salicylic and succinic acids on 13,3-52,0 and 6,4-38,8% respectively depending on weather conditions in the field experiments was noted.

  14. Potentiometric investigation of acid dissociation and anionic homoconjugation equilibria of substituted phenols in dimethyl sulfoxide[Substituted phenols; Acid-base equilibria; Dimethyl sulfoxide (DMSO); Potentiometry

    Energy Technology Data Exchange (ETDEWEB)

    Czaja, Malgorzata; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech. E-mail: lech@chemik.chem.univ.gda.pl

    2003-10-01

    Standard acidity constants, K{sub a}{sup DMSO} (HA), expressed as pK{sub a}{sup DMSO} (HA) values, and anionic homoconjugation constants, K{sup DMSO}{sub AHA{sup -}}, (in the form of lg K{sup DMSO}{sub AHA{sup -}} values) have been determined for 11 substituted phenol-phenolate systems a polar protophilic aprotic solvent, dimethyl sulfoxide (DMSO) with a potentiometric titration. A linear relationship has been determined between lg K{sup DMSO}{sub AHA{sup -}} and pK{sub a}{sup DMSO} (HA). The tendency towards anionic homoconjugation in these systems increases with increasing pK{sub a}{sup DMSO} (HA) that is with declining phenol acidity. The pK{sub a}{sup DMSO} (HA) are correlated with both pK{sub a}{sup W} (HA) water and other polar non-aqeous solvents.

  15. Growth of copper-treated corn roots as affected by EDTA, IAA, succinic acid-2,2-dimethyl hydrazide, vitamins and potassium

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, R; Welkie, G W

    1977-04-01

    Corn roots were treated for 1 hr in a modified Hoagland's solution containing 8 mg/l Cu/sup 2 +/ and either simultaneously or subsequently with various substances, in order to test theories of copper toxicity to roots. Post treatment with IAA, niacin amide, thiamin, or sucrose had no effect on subsequent growth. Addition of excess KCl and succinic acid-2,2-dimethyl hydrazide (an inhibitor of ethylene production) to the copper solution doubled average growth and increased recovery from 27 to 87%. A rinse with EDTA resulted in resumption of normal growth rates and 100% recovery if performed 1 hr after Cu treatment, but this effect was gradually lost in the following 6 to 12 hr. Copper toxicity was increasingly severe as pH of the Cu treating medium increased. Results are not consistent with any theory tested, but they do suggest there is an initial phase of copper-stress which lasts 3 to 6 hr, followed by plant reaction that results in irreversible cessation of growth.

  16. (α,α-dimethyl)glycyl (dmg) PNAs

    Science.gov (United States)

    Gourishankar, Aland; Ganesh, Krishna N.

    2012-01-01

    The design and facile synthesis of sterically constrained new analogs of PNA having gem-dimethyl substitutions on glycine (dmg-PNA-T) is presented. The PNA oligomers [aminoethyl dimethylglycyl (aedmg) and aminopropyl dimethylglycyl (apdmg)] synthesized from the monomers 6 and 12) effected remarkable stabilization of homothyminePNA2:homoadenine DNA/RNA triplexes and mixed base sequence duplexes with target cDNA or RNA. They show a higher binding to DNA relative to that with isosequential RNA. This may be a structural consequence of the sterically rigid gem-dimethyl group, imposing a pre-organized conformation favorable for complex formation with cDNA. The results complement our previous work that had demonstrated that cyclohexanyl-PNAs favor binding with cRNA compared with cDNA and imply that the biophysical and structural properties of PNAs can be directed by introduction of the right rigidity in PNA backbone devoid of chirality. This approach of tweaking selectivity in binding of PNA constructs by installing gem-dimethyl substitution in PNA backbone can be extended to further fine-tuning by similar substitution in the aminoethyl segment as well either individually or in conjunction with present substitution. PMID:22679528

  17. Enhanced dimethyl phthalate biodegradation by accelerating phthalic acid di-oxygenation.

    Science.gov (United States)

    Tang, Yingxia; Zhang, Yongming; Jiang, Ling; Yang, Chao; Rittmann, Bruce E

    2017-12-01

    The aerobic biodegradation of dimethyl phthalate (DMP) is initiated with two hydrolysis reactions that generate an intermediate, phthalic acid (PA), that is further biodegraded through a two-step di-oxygenation reaction. DMP biodegradation is inhibited when PA accumulates, but DMP's biodegradation can be enhanced by adding an exogenous electron donor. We evaluated the effect of adding succinate, acetate, or formate as an exogenous electron donor. PA removal rates were increased by 15 and 30% for initial PA concentrations of 0.3 and 0.6 mM when 0.15 and 0.30 mM succinate, respectively, were added as exogenous electron donor. The same electron-equivalent additions of acetate and formate had the same acceleration impacts on PA removal. Consequently, the DMP-removal rate, even PA coexisting with DMP simultaneously, was accelerated by 37% by simultaneous addition of 0.3 mM succinate. Thus, lowering the accumulation of PA by addition of an electron increased the rate of DMP biodegradation.

  18. (Vapour + liquid) equilibria, volumetric and compressibility behaviour of binary and ternary aqueous solutions of 1-hexyl-3-methylimidazolium chloride, methyl potassium malonate, and ethyl potassium malonate

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Mahdavi, Adibeh

    2012-01-01

    Highlights: ► VLE and volumetry of binary and ternary [C 6 mim][Cl], MPM and EPM aqueous solutions. ► Constant a w lines show small negative deviation from the linear isopiestic relation. ► Solute–water interactions follow the order: EPM > MPM > [C 6 mim][Cl]. ► MPM and EPM have a very weak salting-out effect on [C 6 mim][Cl] aqueous solutions. - Abstract: (Vapour + liquid) equilibrium data (water activity, vapour pressure, osmotic coefficient, and activity coefficient) of binary aqueous solutions of 1-hexyl-3-methylimidazolium chloride ([C 6 mim][Cl]), methyl potassium malonate, and ethyl potassium malonate and ternary {[C 6 mim][Cl] + methyl potassium malonate} and {[C 6 mim][Cl] + ethyl potassium malonate} aqueous solutions were obtained through the isopiestic method at T = 298.15 K. These results reveal that the ionic liquid behaves as surfactant-like and aggregates in aqueous solutions at molality about 0.4 mol · kg −1 . The constant water activity lines of all the ternary systems investigated show small negative deviations from the linear isopiestic relation (Zdanovskii–Stokes–Robinson rule) derived using the semi-ideal hydration model. The density and speed of sound measurements were carried out on solutions of methyl potassium malonate and ethyl potassium malonate in water and of [C 6 mim][Cl] in aqueous solutions of 0.25 mol · kg −1 methyl potassium malonate and ethyl potassium malonate at T = (288.15 to 308.15) K at atmospheric pressure. From the experimental density and speed of sound data, the values of the apparent molar volume, apparent molar isentropic compressibility and excess molar volume were evaluated and from which the infinite dilution apparent molar volume and infinite dilution apparent molar isentropic compressibility were calculated at each temperature. Although, there are no clear differences between the values of the apparent molar volume of [C 6 mim][Cl] in pure water and in methyl potassium malonate or ethyl

  19. Potentiometric investigations of molecular heteroconjugation equilibria of substituted phenol+n-butylamine systems in dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Czaja, MaIgorzata; Baginska, Katarzyna; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech

    2005-01-01

    Molecular heteroconjugation constants, K BHA DMSO and K AHB DMSO , expressed as their logarithms, have been determined by potentiometric titration for eleven substituted phenol+n-butylamine systems in a polar protophilic aprotic solvent, dimethyl sulfoxide (DMSO). An increasing tendency towards molecular heteroconjugation in these systems without proton transfer has been found with increasing pK a DMSO (HA), i.e., with decreasing phenol acidity. Moreover, a linear correlation has been established between the determined lgK BHA DMSO values and pK a DMSO (HA). Furthermore, overall stability constants, lgK o DMSO , could be correlated linearly with pK a DMSO (HA) values

  20. Spectroscopic evidence for ternary surface complexes in the lead(II)-malonic acid-hematite system

    Science.gov (United States)

    Lenhart, J.J.; Bargar, J.R.; Davis, J.A.

    2001-01-01

    Using extended X-ray absorption fine structure (EXAFS) and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) measurements, we examined the sorption of Pb(II) to hematite in the presence of malonic acid. Pb LIII-edge EXAFS measurements performed in the presence of malonate indicate the presence of both Fe and C neighbors, suggesting that a major fraction of surface-bound malonate is bonded to adsorbed Pb(II). In the absence of Pb(II), ATR-FTIR measurements of sorbed malonate suggest the formation of more than one malonate surface complex. The dissimilarity of the IR spectrum of malonate sorbed on hematite to those for aqueous malonate suggest at least one of the sorbed malonate species is directly coordinated to surface Fe atoms in an inner-sphere mode. In the presence of Pb, little change is seen in the IR spectrum for sorbed malonate, indicating that geometry of malonate as it coordinates to sorbed Pb(II) adions is similar to the geometry of malonate as it coordinates to Fe in the hematite surface. Fits of the raw EXAFS spectra collected from pH 4 to pH 8 result in average Pb-C distances of 2.98 to 3.14 A??, suggesting the presence of both four- and six-membered Pb-malonate rings. The IR results are consistent with this interpretation. Thus, our results suggest that malonate binds to sorbed Pb(II) adions, forming ternary metal-bridging surface complexes. ?? 2001 Academic Press.

  1. Potentiometric investigation of acid dissociation and anionic homoconjugation equilibria of substituted phenols in dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Czaja, Malgorzata; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech.

    2003-01-01

    Standard acidity constants, K a DMSO (HA), expressed as pK a DMSO (HA) values, and anionic homoconjugation constants, K DMSO AHA - , (in the form of lg K DMSO AHA - values) have been determined for 11 substituted phenol-phenolate systems a polar protophilic aprotic solvent, dimethyl sulfoxide (DMSO) with a potentiometric titration. A linear relationship has been determined between lg K DMSO AHA - and pK a DMSO (HA). The tendency towards anionic homoconjugation in these systems increases with increasing pK a DMSO (HA) that is with declining phenol acidity. The pK a DMSO (HA) are correlated with both pK a W (HA) water and other polar non-aqeous solvents

  2. Potentiometric investigations of molecular heteroconjugation equilibria of substituted phenol+n-butylamine systems in dimethyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Czaja, MaIgorzata [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Baginska, Katarzyna [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Kozak, Anna [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2005-08-15

    Molecular heteroconjugation constants, K{sub BHA}{sup DMSO} and K{sub AHB}{sup DMSO}, expressed as their logarithms, have been determined by potentiometric titration for eleven substituted phenol+n-butylamine systems in a polar protophilic aprotic solvent, dimethyl sulfoxide (DMSO). An increasing tendency towards molecular heteroconjugation in these systems without proton transfer has been found with increasing pK{sub a}{sup DMSO} (HA), i.e., with decreasing phenol acidity. Moreover, a linear correlation has been established between the determined lgK{sub BHA}{sup DMSO} values and pK{sub a}{sup DMSO} (HA). Furthermore, overall stability constants, lgK{sub o}{sup DMSO}, could be correlated linearly with pK{sub a}{sup DMSO} (HA) values.

  3. MODIFIKASI ASAM SUKSINAT - GELOMBANG PENDEK UNTUK\tPRODUKSI TAPIOKA SUKSINAT Succinic Acid-Microwave Modification to Produce Succinic Tapioca

    Directory of Open Access Journals (Sweden)

    Heny Herawati

    2012-05-01

    Full Text Available Indonesia as tropical country has great cassava potency. The great chance of cassava product development could be increased its added value through modified tapioca processing. One of modified starch that could be implemented as a food additive is succinic starch. The tapioca succinilation processed through combination process of reacting tapioca with succinic acid and microwave treatment. The research method was conducted by factorial design with 3 factors: substrate concentration (30 %, 40 %, succinic acid concentration (1 %, 3 %, 5 %, and drying method (oven and microwave. Succinic tapioca was analyzed both physical and chemical characteristics, while optimal product was fur- ther analyzed for nutrition contents and surface microstructure using SEM. Succinic acid and microwave modification influenced to the physical and chemical succinic tapioca, except ash content. The highest substitution degree value was 0.929 which was obtained by combination of substrate concentration 40 %, succinic acid added 5 % and microwave processed. The change of granule size was not significant, just the distribution among granule correlated with the tapi- oca modification. The succinic tapioca granule size ranged 5.35 µm until 17.20 µm with average 11.15 µm. Succinic tapioca characteristic hopefully could be advanced food implementation. ABSTRAK Indonesia merupakan negara tropis yang memiliki potensi produksi ubi kayu yang cukup besar. Peluang pengem- bangan produk berbasis ubi kayu di Indonesia masih cukup besar diantaranya yaitu peningkatan nilai tambah ubi kayu melalui proses modifikasi tapioka. Salah satu potensi pati termodifikasi yang dapat dipergunakan untuk bahan tambahan makanan yaitu pati suksinat. Pada penelitian ini proses suksinilasi tapioka dilakukan dengan cara mereak- sikan asam suksinat yang dikombinasikan dengan mempergunakan microwave. Metodologi penelitian yang dilakukan menggunakan rancangan faktorial dengan 3 faktor, yaitu konsentrasi

  4. The Succinated Proteome

    Energy Technology Data Exchange (ETDEWEB)

    Merkley, Eric D.; Metz, Thomas O.; Smith, Richard D.; Baynes, John; Frizell, Norma

    2014-03-30

    Succination is a chemical modification of cysteine in protein by the Krebs cycle intermediate, fumarate, yielding S-(2-succino)cysteine (2SC). Intracellular fumarate concentration and succination of proteins are increased by hyperpolarization of the inner mitochondrial membrane, in concert with mitochondrial, endoplasmic reticulum (ER) and oxidative stress in adipocytes grown in high glucose medium and in adipose tissue in obesity and diabetes. Increased succination of proteins is also detected in the kidney of a fumarase conditional knock-out mouse which develops renal tumors. Keap1, the gatekeeper of the antioxidant response, was identified as a major succinated protein in renal cancer cells, suggesting that succination may play a role in activation of the antioxidant response. A wide range of proteins is subject to succination, including enzymes, adipokines, cytoskeletal proteins and ER chaperones with functional cysteine residues. There is also significant overlap between succinated and glutathionylated proteins, and with proteins containing cysteine residues that are readily oxidized to the sulfenic (cysteic) acid. Succination of adipocyte proteins is inhibited by uncouplers, which discharge the mitochondrial membrane potential (Δψm) and by ER stress inhibitors. 2SC serves as a biomarker of mitochondrial stress or dysfunction in chronic diseases, such as obesity, diabetes and cancer, and recent studies suggest that succination is a mechanistic link between mitochondrial dysfunction, oxidative and ER stress, and cellular progression toward apoptosis. In this article, we review the history of the succinated proteome and the challenges associated with measuring this non-enzymatic post-translational modification of proteins by proteomics approaches.

  5. Escherichia coli yjjPB genes encode a succinate transporter important for succinate production.

    Science.gov (United States)

    Fukui, Keita; Nanatani, Kei; Hara, Yoshihiko; Yamakami, Suguru; Yahagi, Daiki; Chinen, Akito; Tokura, Mitsunori; Abe, Keietsu

    2017-09-01

    Under anaerobic conditions, Escherichia coli produces succinate from glucose via the reductive tricarboxylic acid cycle. To date, however, no genes encoding succinate exporters have been established in E. coli. Therefore, we attempted to identify genes encoding succinate exporters by screening an E. coli MG1655 genome library. We identified the yjjPB genes as candidates encoding a succinate transporter, which enhanced succinate production in Pantoea ananatis under aerobic conditions. A complementation assay conducted in Corynebacterium glutamicum strain AJ110655ΔsucE1 demonstrated that both YjjP and YjjB are required for the restoration of succinate production. Furthermore, deletion of yjjPB decreased succinate production in E. coli by 70% under anaerobic conditions. Taken together, these results suggest that YjjPB constitutes a succinate transporter in E. coli and that the products of both genes are required for succinate export.

  6. Microwave-assisted synthesis of α-aryl malonates: Key intermediates for the

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ibrahim

    2016-11-01

    Full Text Available We disclose a new microwave-assisted protocol for the effective α-arylation of diethyl malonate. The coupling of aryl halides with diethyl malonate proceeds smoothly in short reaction time in the presence of a catalytic amount of Cu(OTf2, 2-picolinic acid and Cs2CO3 in toluene using microwave irradiation. The resulting α-aryl malonates are then used as key intermediates for synthesis of variety of heterocyclic compounds, including benzodiazepines, isoquinolines and pyrrolopyridine scaffolds.

  7. Synthesis and spectral properties of diethyl organylchalcogenoalkyl(alkyl)malonates, RX(CH/sub 2/)/sub n/CR'(COOC/sub 2/H/sub 5/)/sub 2/, and 5-alkyl-5-(organylchalcogenoalkyl)barbiturates, RX(CH/sub 2/)/sub n/C(R')CONHC(Y)NHCO (X = Se, Te)

    Energy Technology Data Exchange (ETDEWEB)

    Grigsby, Jr, R A; Irgolic, K J; Knapp, Jr, F F

    1983-01-01

    Barbiturates substituted at the 5-position with organyltelluroalkyl or organylselenoalkyl groups were prepared by ring annulation of appropriately substituted diethyl malonates with urea or thiourea. The substituted diethyl malonates (phenyltellurobutyl(ethyl), i-propyltelluropropyl(ethyl), i-propyltelluropropyl(allyl), i-propyselenopropyl(ethyl), and phenylselenohexyl(methyl)) were prepared in 55-91% yield by reaction of diethyl omega-bromoalkyl(alkyl)malonates with organyltellurolates or selenolates (RXNa; X = Se, Te) in ethanol/benzene. The following barbiturates were obtained in 28-84% yield: phenyltellurobutyl(ethyl), m.p. 100/sup 0/C; i-propyltelluropropyl(ethyl), m.p. 119/sup 0/C; i-propylselenopropyl(ethyl), m.p. 137/sup 0/C; phenyl-selenohexyl(methyl), m.p. 124/sup 0/C. The 5-substituted thiobarbiturates i-propyltelluropropyl(ethyl)-(m.p. 75/sup 0/C) and i-propylselenopropyl(ethyl)thiobarbiturate (m.p. 83/sup 0/C) were isolated in 32 and 20% yield, respectively. The barbiturates and thiobarbiturates were purified by chromatography and recrystallization and characterized by elemental analyses, mass spectrometry, /sup 1/H, /sup 125/Te and /sup 77/Se NMR spectroscopy and UV-VIS spectrometry. The chalcogenobarbiturates radiolabeled with /sup 123m/Te or /sup 77/Se may be useful as brain imaging agents. 31 references, 4 tables.

  8. THE SUCCINATED PROTEOME

    OpenAIRE

    Merkley, Eric D.; Metz, Thomas O.; Smith, Richard D.; Baynes, John W.; Frizzell, Norma

    2013-01-01

    The post-translational modifications (PTMs) of cysteine residues include oxidation, S-glutathionylation, S-nitrosylation, and succination, all of which modify protein function or turnover in response to a changing intracellular redox environment. Succination is a chemical modification of cysteine in proteins by the Krebs cycle intermediate, fumarate, yielding S-(2-succino) cysteine (2SC). Intracellular fumarate concentration and succination of proteins are increased by hyperpolarization of th...

  9. A Rare Case of Malonic Aciduria Diagnosed by Newborn Screening in Qatar

    Directory of Open Access Journals (Sweden)

    Mamatha Ramaswamy

    2017-03-01

    Full Text Available Malonic aciduria is a rare autosomal recessive organic acid disorder. With the widespread use of tandem mass spectrometry for analysis of the amino acid/acylcarnitine profile on dried blood spots for newborn screening (NBS, this condition can be readily diagnosed and can be included in the organic acid screen in NBS programs. In Qatar, we report the first case of an asymptomatic baby screened and diagnosed with malonic aciduria through NBS. This patient has a genetic variant of malonyl-CoA decarboxylase that has not been previously reported in the literature. This condition should be differentiated from a similar disorder, combined malonic and methylmalonic aciduria. The clinical phenotype of malonic aciduria is variable and the pathophysiology is not fully understood. There is no established guidance or recommendations regarding the appropriate treatment regimen, dietary therapy or regular follow-up of these patients. Most available evidence for treatment is based on a single study or case report.

  10. Effect of chelate ring sizes and their substitution on intensities of hypersensitive transitions of lanthanoids (Ln(III)) ions and j (total quantum number profiles)

    International Nuclear Information System (INIS)

    Dubey, J.; Pandey, P.; Yadav, A.; Limaye, S.N.

    1998-01-01

    Full text: Electronic spectral studies of Pr(III), Nd(III), Sm(III) Dy(III), Eu(III) and Tm(III) complexes with some aliphatic and aromatic O-O donor ligands viz., Glycolic (gly), Malonic (main) Succinic (suc), Glutaric (glut), Salicylic (sal), Phthalic acids and Catechol (cat) having varied chelate ring sizes and different substitutions as side chains have been carried out with a view to study the effect of chelate ring sizes on the intensities of hypersensitive and pseudo-hypersensitive transitions in lanthanoids. The intensities of these HST transitions have also been correlated with the total quantum number (J) of the lanthanoid metal ions in order to seek a probable mechanism for the phenomenon hypersensitivity. A comparison of the spectral and nephelauxetic parameters for Pr(III), Nd(III), Sm(III) with Dy(III) Er(III) and Tm(III) exhibit a variation in the bonding pattern from electrostatic to covalo-electrostatic from pre-Gd elements to post-Gd elements. The J-(total) quantum number profiles of the oscillator strength values for the specific HST transitions have also been examined

  11. PREPARATION OF DIETHYL MALONATE ADDUCTS FROM ...

    African Journals Online (AJOL)

    Preferred Customer

    compounds such as the antiinflammatory and analgesic drugs indomethacin or aclofenac [14]. A mild and efficient procedure for the introduction of the methylenecarboxy group into functionalized molecules is thus of great interest. In this study, novel chalcone-diethyl malonate derivatives that can be used in the synthesis.

  12. Effect of succinic acid concentration in poly(glycerol citrate/succinate) properties

    International Nuclear Information System (INIS)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Jose, Nadia M.

    2011-01-01

    In this work were prepared and characterized polymer based on glycerol, citric and succinic acid, in three different ratios to evaluate the effect of succinic acid concentration in materials properties. The polymers were obtained by polycondensation reaction between polyol and poly acids, and were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The materials are amorphous polyesters and its thermal and morphological properties change depending on the succinic acid concentration. (author)

  13. Commentary on Malone: Who Founded Behaviorism?

    Science.gov (United States)

    Reese, Hayne W

    2015-05-01

    Malone (The Behavior Analyst, 37, 1-12 2014) argued that the emergence of behaviorism was inevitable with or without Watson's participation, mainly because protobehavioral ideas and dissatisfaction with classical structuralism were already widespread. However, the first premise is questionable because many of the ideas Malone cited were consistent with structuralism rather than behaviorism, and even if both premises were true they would not make the emergence of behaviorism-or anything else-inevitable. Historical evidence for inevitability is always retrospective and therefore always allows the logical fallacy of "after this, therefore because of this." In the relevant real world Watson existed, he was a psychologist, he was the first to publish an article that described a "behaviorism," and he promoted his behaviorism in later works. Stories about what would have happened without Watson's participation are therefore counterfactual and this lack of historicity makes the stories fictional rather than scientific. In the real world, Watson founded behaviorism.

  14. Synthesis and performances of poly(butylene-succinate) with enhanced viscosity and crystallization rate via introducing a small amount of diacetylene groups

    Institute of Scientific and Technical Information of China (English)

    Gui-Cheng Liu; Wen-Qiang Zhang; Xiu-Li Wang; Yu-Zhong Wang

    2017-01-01

    A cross-linkable comonomer containing a diacetylene group,named dimethyl 4,4'-(buta-1,3-diyne-1,4-diyl)dibenzoate (DA) was synthesized and copolymerized with dimethyl succinate and 1,4-butanediol to prepare a series of slightly cross-linked PBS copolyesters (PBDA Sx).The chemical structure,crystallization and theological behaviours of PBDASx were well investigated.Compared to neat PBS,PBDASx showed the greatly increased crystallization rate because of the promoting nucleation of the cross-linking domains,and the XRD results indicated that it had no influence on crystallization structure of PBS.The rheological behaviours indicate that PBDASx possessed higher viscosity than neat PBS even at high shear rate and temperature.PBDAS0.3 exhibited better comprehensive properties than neat PBS,which will widen applications of PBS.

  15. Overexpression of isocitrate lyase-glyoxylate bypass influence on metabolism in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; Otero, José Manuel; Olivares Hernandez, Roberto

    2009-01-01

    of the cells was investigated. Inhibition of SDH was expected to lead to succinate production, but this was not observed. There was an increase in citrate and oxalate production in the wild-type strain. Furthermore, in the strain with over-expression of icl the organic acid production shifted from fumarate...... towards malate production when malonate was added to the cultivation medium. Overall, the icl over-expression and malonate addition had a significant impact on metabolism and on organic acid production profiles. Although the expected succinate and malate formation was not observed, a distinct...

  16. Succinic Acid: Technology Development and Commercialization

    Directory of Open Access Journals (Sweden)

    Nhuan P. Nghiem

    2017-06-01

    Full Text Available Succinic acid is a precursor of many important, large-volume industrial chemicals and consumer products. It was once common knowledge that many ruminant microorganisms accumulated succinic acid under anaerobic conditions. However, it was not until the discovery of Anaerobiospirillum succiniciproducens at the Michigan Biotechnology Institute (MBI, which was capable of producing succinic acid up to about 50 g/L under optimum conditions, that the commercial feasibility of producing the compound by biological processes was realized. Other microbial strains capable of producing succinic acid to high final concentrations subsequently were isolated and engineered, followed by development of fermentation processes for their uses. Processes for recovery and purification of succinic acid from fermentation broths were simultaneously established along with new applications of succinic acid, e.g., production of biodegradable deicing compounds and solvents. Several technologies for the fermentation-based production of succinic acid and the subsequent conversion to useful products are currently commercialized. This review gives a summary of the development of microbial strains, their fermentation, and the importance of the down-stream recovery and purification efforts to suit various applications in the context of their current commercialization status for biologically derived succinic acid.

  17. Prospects for a bio-based succinate industry.

    Science.gov (United States)

    McKinlay, James B; Vieille, C; Zeikus, J Gregory

    2007-09-01

    Bio-based succinate is receiving increasing attention as a potential intermediary feedstock for replacing a large petrochemical-based bulk chemical market. The prospective economical and environmental benefits of a bio-based succinate industry have motivated research and development of succinate-producing organisms. Bio-based succinate is still faced with the challenge of becoming cost competitive against petrochemical-based alternatives. High succinate concentrations must be produced at high rates, with little or no by-products to most efficiently use substrates and to simplify purification procedures. Herein are described the current prospects for a bio-based succinate industry, with emphasis on specific bacteria that show the greatest promise for industrial succinate production. The succinate-producing characteristics and the metabolic pathway used by each bacterial species are described, and the advantages and disadvantages of each bacterial system are discussed.

  18. Laboratory rotational spectrum of singly 13C-substituted dimethyl ether up to 1.5 THz and interstellar detection of 13CH_3O12CH_3 - a fruitful interplay between laboratory work and inter

    Science.gov (United States)

    Koerber, M.; Bisschop, S.; Endres, C.; Lewen, F.; Schlemmer, S.

    2011-05-01

    Dimethyl ether (CH_3OCH_3) is found in high abundance in star forming regions. However, the interstellar formation process of dimethyl ether still remains unclear up to now. In current gas-grain models gas-phase synthesis via self-methylation of methanol evaporating from grains is discussed in contrast to the surface reaction of CH_3 with successively hydrogenated CO (Garrod & Herbst 2006). An observational test for the formation mechanism has been proposed by Charnley et al. (2004) making use of the 13C fractionation into CO at low temperatures on grains: Comparing the 12C/13C ratio of molecules to the 12CO/13CO ratio allows to distinguish between formation from CO on cold grains and pure gas-phase formation routes. The isotopic ratio of species like dimethyl ether thus can be used as a tracer of the chemical evolution of the observed region. Due to its two methyl groups undergoing large amplitude motions and a relatively strong dipole moment of μ = 1.302 D it shows a strong and dense complex spectrum all over the terahertz region relevant for Herschel and ALMA observations. Accurate transition frequencies are needed to interpret the astronomical spectra. For the main isotopologue extensive data are now available (Endres et al. 2009). However, due to the greatly improved sensitivity of the new observatories isotopic species of abundant molecules like dimethyl ether are appearing in the spectra as well. In this work we present laboratory measurements of singly 13C-substituted dimethyl ether (13CH_3O12CH_3) up to 1.5 THz. More than 1700 transitions of 13CH_3O12CH_3 with rotational quantum numbers up to J = 53 and K = 25 have been analyzed. Based on the laboratory measurements singly 13C-substituted dimethyl ether has been detected for the first time in the spectrum of G327.3-0.6 (Bisschop et al. in prep.) and a preliminary value for the 12C/13C abundance ratio has been determined.

  19. Genetics Home Reference: combined malonic and methylmalonic aciduria

    Science.gov (United States)

    ... links) Health Topic: Genetic Brain Disorders Health Topic: Lipid Metabolism Disorders Genetic and Rare Diseases Information Center (1 link) Combined malonic and methylmalonic aciduria Additional NIH Resources (1 link) National Human Genome Research Institute: NHGRI Researchers Serve Up Mysterious ...

  20. Collections XVII (The Malone Society)

    OpenAIRE

    Keenan, Siobhan; Giddens, Eugene

    2016-01-01

    Collections XVII is the latest volume in the Malone Society's pioneering series of editions of miscellaneous documents relating to English theatre and drama before 1642. It is likely to be of special interest not only to early theatre historians but to those working on Tudor and Stuart court and civic culture, manuscript writing, household drama and early modern women's writing, as it publishes new material in each of these fields. The book includes items such as Revels Office accounts, a pla...

  1. Effect of Hydroxyl Monomers on the Enzymatic Degradation of Poly(ethylene succinate, Poly(butylene succinate, and Poly(hexylene succinate

    Directory of Open Access Journals (Sweden)

    Zhenhui Bai

    2018-01-01

    Full Text Available Poly(ethylene succinate (PES, poly(butylene succinate (PBS, and poly(hexylene succinate (PHS, were synthesized using succinic acid and different dihydric alcohols as materials. Enzymatic degradability by cutinase of the three kinds of polyesters was studied, as well as their solid-state properties. The biodegradation behavior relied heavily on the distance between ester groups, crystallinity, and the hydrophilicity-hydrophobicity balance of polyester surfaces. The weight loss through degradation of the three kinds of polyesters with different hydroxyl monomers took place in the order PHS > PBS > PES. The degradation behavior of the polyesters before and after degradation was analyzed by scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The decrease in relative intensity at 1800–1650 estedpolyesters were degraded simultaneously. The frequencies of the crystalline and amorphous bands were almost identical before and after degradation. Thus, enzymatic degradation did not change the crystalline structure but destroyed it, and the degree of crystallinity markedly decreased. The molecular weight and polydispersity index only changed slightly. The thermal stability of the three kinds of polyesters decreased during enzymatic degradation.

  2. Movers and shakers: David M. Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-01-25

    Jan 25, 2011 ... ... been met with praise in the two worlds that he has known best—diplomacy and research. ... Malone addressed this internal criticism while serving a six-year term as .... “And David probably did as well as anybody ever has.”.

  3. A novel mutation in the succinate dehydrogenase subunit D gene in siblings with the hereditary paraganglioma–pheochromocytoma syndrome

    Directory of Open Access Journals (Sweden)

    Chaithra Prasad

    2014-10-01

    Full Text Available Germline mutations in the succinate dehydrogenase complex subunit D gene are now known to be associated with hereditary paraganglioma–pheochromocytoma syndromes. Since the initial succinate dehydrogenase complex subunit D gene mutation was identified about a decade ago, more than 131 unique variants have been reported. We report the case of two siblings presenting with multiple paragangliomas and pheochromocytomas; they were both found to carry a mutation in the succinate dehydrogenase complex subunit D gene involving a substitution of thymine to guanine at nucleotide 236 in exon 3. This particular mutation of the succinate dehydrogenase complex subunit D gene has only been reported in one previous patient in Japan; this is, therefore, the first report of this pathogenic mutation in siblings and the first report of this mutation in North America. With continued screening of more individuals, we will be able to create a robust mutation database that can help us understand disease patterns associated with particular variants and may be a starting point in the development of new therapies for familial paraganglioma syndromes.

  4. 21 CFR 582.1091 - Succinic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Succinic acid. 582.1091 Section 582.1091 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1091 Succinic acid. (a) Product. Succinic acid. (b) Conditions of use. This substance is generally...

  5. Chemical evolution studies: the radiolysis and thermal decomposition of malonic acid

    International Nuclear Information System (INIS)

    Cruz-Castaneda, J.; Negron-Mendoza, A.; Heredia, A.; Ramos-Bernal, S.; Villafane-Barajas, S.; Frias, D.; Colin-Garcia, M.

    2015-01-01

    In the context of chemical evolution a simulation of a hydrothermal vent was performed. The thermolysis and radiolysis of malonic acid in aqueous solution were studied. The thermolysis was done by heating the samples (95 deg C) and radiolysis using gamma radiation. Products were identified by gas chromatography and gas chromatography-mass spectrometry. The thermal treatment produced acetic acid and CO 2 . The radiolysis experiments yield carbon dioxide, acetic acid, and di- and tricarboxylic acids. A theoretical model of the chemical process occurring under irradiation was developed; this was able to reproduce formation of products and the consumption of malonic acid. (author)

  6. Succinic acid production from Jerusalem artichoke

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi; Karakashev, Dimitar Borisov; Angelidaki, Irini

    In this work, A. succinogenes 130Z was used to produce succinic acid from Jerusalem artichoke tuber hydrolysate. Results showed that both fructose and glucose in the tuber hydrolysate were utilized for succinic acid production. The sugar utilization was found to be dependent on process control...... that Jerusalem artichoke tubers could be utilized for production of bio-succinic acid....

  7. Cannabinoid CB2 receptor agonists protect the striatum against malonate toxicity: relevance for Huntington’s disease

    Science.gov (United States)

    Sagredo, Onintza; González, Sara; Aroyo, Ilia; Pazos, María Ruth; Benito, Cristina; Lastres-Becker, Isabel; Romero, Juan P.; Tolón, Rosa M.; Mechoulam, Raphael; Brouillet, Emmanuel; Romero, Julián; Fernández-Ruiz, Javier

    2009-01-01

    Cannabinoid agonists might serve as neuroprotective agents in neurodegenerative disorders. Here, we examined this hypothesis in a rat model of Huntington’s disease (HD) generated by intrastriatal injection of the mitochondrial complex II inhibitor malonate. Our results showed that only compounds able to activate CB2 receptors were capable of protecting striatal projection neurons from malonate-induced death. That CB2 receptor agonists are neuroprotective was confirmed by using the selective CB2 receptor antagonist, SR144528, and by the observation that mice deficient in CB2 receptor were more sensitive to malonate than wild-type animals. CB2 receptors are scarce in the striatum in healthy conditions but they are markedly up-regulated after the lesion with malonate. Studies of double immunostaining revealed a significant presence of CB2 receptors in cells labelled with the marker of reactive microglia OX-42, and also in cells labelled with GFAP (a marker of astrocytes). We further showed that the activation of CB2 receptors significantly reduced the levels of tumor necrosis factor-α (TNF-α) that had been increased by the lesion with malonate. In summary, our results demonstrate that stimulation of CB2 receptors protect the striatum against malonate toxicity, likely through a mechanism involving glial cells, in particular reactive microglial cells in which CB2 receptors would be up-regulated in response to the lesion. Activation of these receptors would reduce the generation of proinflammatory molecules like TNF-α. Altogether our results support the hypothesis that CB2 receptors could constitute a therapeutic target to slowdown neurodegeneration in HD. PMID:19115380

  8. 21 CFR 184.1091 - Succinic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Succinic acid. 184.1091 Section 184.1091 Food and... Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4H6O4, CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical 1,4-butanedioic acid. It is...

  9. Thermodynamic properties of actinide complexes. IV. Thorium(IV)- and uranyl(VI)-malonate systems

    Energy Technology Data Exchange (ETDEWEB)

    Di Bernardo, P; Di Napoli, V; Cassol, A; Magon, L [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

    1977-01-01

    The stability constants and the enthalpies of formation of thorium(IV)- and uranyl(VI)-malonate complexes have been determined by potentiometric and calorimetric titrations in 1.00 M solutions of Na(ClO/sub 4/) at 25/sup 0/C. All complexes formed are found to be stabilized by a large entropy gain. The values for the stability constants agree with an ionic bonding model. The malonate behaves as a bidentate ligand forming only chelate complexes.

  10. Nucleophilic Substitution Reactions of N-Methyl α-Bromoacetanilides with Benzylamines in Dimethyl Sulfoxide

    International Nuclear Information System (INIS)

    Adhikary, Keshab Kumar; Lee, Hai Whang

    2011-01-01

    Kinetic studies of the reactions of N-methyl-Y-α-bromoacetanilides with substituted X-benzylamines have been carried out in dimethyl sulfoxide at 25.0 .deg. C. The Hammett plots for substituent X variations in the nucleophiles (log k N vs σ X ) are slightly biphasic concave upwards/downwards, while the Bronsted plots (log k N vs pK a ) are biphasic concave downwards with breakpoints at X = H. The Hammett plots for substituent Y variations in the substrates (log k N vs σ Y ) are biphasic concave upwards/downwards with breakpoints at Y = H. The cross-interaction constant ρ XY values are all negative: ρ XY = -0.32 for X = Y = electron-donating: -0.22 for X = electron-withdrawing and Y = electron-donating: -1.80 for X = electron-donating and Y = electronwithdrawing: -1.43 for X = Y = electron-withdrawing substituents. Deuterated kinetic isotope effects are primary normal (k H /k D > 1) for Y = electron-donating, while secondary inverse (k H /k D < 1) for Y = electronwithdrawing substituent. The proposed mechanisms of the benzylaminolyses of N-methyl-Y-α-bromoacetanilides are a concerted mechanism with a five membered ring TS involving hydrogen bonding between hydrogen (deuterium) atom in N-H(D) and oxygen atom in C = O for Y = electron-donating, while a concerted mechanism with an enolate-like TS in which the nucleophile attacks the α-carbon for Y = electronwithdrawing substituents

  11. (α,α-dimethyl)glycyl (dmg) PNAs: achiral PNA analogs that form stronger hybrids with cDNA relative to isosequential RNA.

    Science.gov (United States)

    Gourishankar, Aland; Ganesh, Krishna N

    2012-01-01

    The design and facile synthesis of sterically constrained new analogs of PNA having gem-dimethyl substitutions on glycine (dmg-PNA-T) is presented. The PNA oligomers [aminoethyl dimethylglycyl (aedmg) and aminopropyl dimethylglycyl (apdmg)] synthesized from the monomers 6 and 12) effected remarkable stabilization of homothyminePNA(2):homoadenine DNA/RNA triplexes and mixed base sequence duplexes with target cDNA or RNA. They show a higher binding to DNA relative to that with isosequential RNA. This may be a structural consequence of the sterically rigid gem-dimethyl group, imposing a pre-organized conformation favorable for complex formation with cDNA. The results complement our previous work that had demonstrated that cyclohexanyl-PNAs favor binding with cRNA compared with cDNA and imply that the biophysical and structural properties of PNAs can be directed by introduction of the right rigidity in PNA backbone devoid of chirality. This approach of tweaking selectivity in binding of PNA constructs by installing gem-dimethyl substitution in PNA backbone can be extended to further fine-tuning by similar substitution in the aminoethyl segment as well either individually or in conjunction with present substitution.

  12. Synthesis and characterization of a novel multiblock copolyester containing poly(ethylene succinate) and poly(butylene succinate)

    International Nuclear Information System (INIS)

    Zhu Qunying; He Yisong; Zeng Jianbing; Huang Qing; Wang Yuzhong

    2011-01-01

    Highlights: → High-molecular-weight biodegradable multiblock copolyester containing PBS and PES segments was achieved. → PBS and PES are miscible with a single glass transition regardless of composition. → The multiblock copolyester showed excellent tensile strength and elongation at break. → The multiblock copolyester can serve as a potential substitute for conventional non-biodegradable commodity plastics. - Abstract: Multiblock copolyester (PBS-b-PES) containing poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) was successfully synthesized by chain-extension of dihydroxyl terminated PBS (HO-PBS-OH) and PES (HO-PES-OH) using 1,6-hexmethylene diisocyanate (HDI) as a chain extender. The chemical structures, molecular weights, crystallization behaviors, thermal and mechanical properties of the copolyesters were characterized by proton nuclear magnetic resonance spectroscopy ( 1 H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), wide-angle X-ray diffraction (WAXD), tensile testing and hydrolytic degradation. High-molecular-weight copolyesters with M w more than 2.0 x 10 5 g mol -1 were easily obtained through chain-extension. The copolyesters showed a single glass transition temperature (T g ) which increased with PES content. The melting point temperature (T m ) and relative degree of crystallinity (X c ) of the copolyesters decreased first and then increased with PES content. The copolyesters manifested excellent mechanical properties, for example, PBS 5 -b-PES 5 had fracture stress of 61.8 MPa and fracture strain of 1173%. The chain-extension reaction provided a very effective way to produce high molecular weight multiblock copolyesters.

  13. Malonic acid: A potential reagent in decontamination processes for Ni-rich alloy surfaces

    International Nuclear Information System (INIS)

    Garcia, D.; Bruyere, V.I.E.; Bordoni, R.; Olmedo, A.M.; Morando, P.J.

    2011-01-01

    The ability of malonic acid as a dissolution agent toward synthetic Ni ferrite and Alloy 600 and 800 corrosion products was explored. Its performance in the dissolution kinetics of Ni ferrite powders was compared with the one of oxalic acid. Kinetic parameters were obtained and the dependency on external Fe(II) was modelled. Oxidized samples used in descaling tests were prepared by exposure of coupons of both alloys to lithiated aqueous solutions, under hydrothermal conditions and hydrogen overpressure, simulating PHWR conditions. Oxide layer morphology, the influence of exposure time to corrosive medium and LiOH concentration on its thickness were characterized. Descaling tests consisting on a two-stage method (a first oxidizing step with alkaline permanganate followed by a reducing step with oxalic or malonic acid were carried out). Results were compared to those obtained with a well known chemical cleaning formulation (APAC: Alkaline Permanganate Ammonium Citrate) used in decontamination of several reactors and loops and the competitiveness of malonic acid was demonstrated.

  14. Malonic acid: A potential reagent in decontamination processes for Ni-rich alloy surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, D.; Bruyere, V.I.E. [Gerencia Quimica, Comision Nacional de Energia Atomica, Centro Atomico Constituyentes, Av. Gral Paz 1499, 1650 San Martin, Prov. de Buenos Aires, Republica Argentina (Argentina); Instituto de Tecnologia, Prof. Jorge Sabato, Universidad Nacional de General San Martin, CNEA, CAC (Argentina); Bordoni, R.; Olmedo, A.M. [Gerencia Quimica, Comision Nacional de Energia Atomica, Centro Atomico Constituyentes, Av. Gral Paz 1499, 1650 San Martin, Prov. de Buenos Aires, Republica Argentina (Argentina); Morando, P.J., E-mail: morando@cnea.gov.ar [Gerencia Quimica, Comision Nacional de Energia Atomica, Centro Atomico Constituyentes, Av. Gral Paz 1499, 1650 San Martin, Prov. de Buenos Aires, Republica Argentina (Argentina); Instituto de Tecnologia, Prof. Jorge Sabato, Universidad Nacional de General San Martin, CNEA, CAC (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina)

    2011-05-01

    The ability of malonic acid as a dissolution agent toward synthetic Ni ferrite and Alloy 600 and 800 corrosion products was explored. Its performance in the dissolution kinetics of Ni ferrite powders was compared with the one of oxalic acid. Kinetic parameters were obtained and the dependency on external Fe(II) was modelled. Oxidized samples used in descaling tests were prepared by exposure of coupons of both alloys to lithiated aqueous solutions, under hydrothermal conditions and hydrogen overpressure, simulating PHWR conditions. Oxide layer morphology, the influence of exposure time to corrosive medium and LiOH concentration on its thickness were characterized. Descaling tests consisting on a two-stage method (a first oxidizing step with alkaline permanganate followed by a reducing step with oxalic or malonic acid were carried out). Results were compared to those obtained with a well known chemical cleaning formulation (APAC: Alkaline Permanganate Ammonium Citrate) used in decontamination of several reactors and loops and the competitiveness of malonic acid was demonstrated.

  15. Ortho-substituted triptycene-based diamines, monomers, and polymers, methods of making and uses thereof

    KAUST Repository

    Ghanem, Bader Saleh

    2017-04-13

    Described herein are ortho-dimethyl-substituted and tetramethyi-substituted triptycene-containing diamine monomers and microporous triptycene-based poiyimides and poiyamides, and methods of making the monomers and polymers.

  16. Ortho-substituted triptycene-based diamines, monomers, and polymers, methods of making and uses thereof

    KAUST Repository

    Ghanem, Bader Saleh; Pinnau, Ingo

    2017-01-01

    Described herein are ortho-dimethyl-substituted and tetramethyi-substituted triptycene-containing diamine monomers and microporous triptycene-based poiyimides and poiyamides, and methods of making the monomers and polymers.

  17. The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films

    Science.gov (United States)

    Ren, Jianjun; Zuo, Yu

    2012-11-01

    The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films were studied. The voltage-time response for galvanostatic anodization of aluminum in malonic acid solution exhibits a conventional three-stage feature but the formation voltage is much higher. With the increase of electrolyte concentration, the electrolyte viscosity increases simultaneously and the high viscosity decreases the film growth rate. With the concentration increase of the malonic acid electrolyte, the critical current density that initiates local "burning" on the sample surface decreases. For malonic acid anodization, the field-assisted dissolution on the oxide surface is relatively weak and the nucleation of pores is more difficult, which results in greater barrier layer thickness and larger cell dimension. The embryo of the porous structure of anodic film has been created within the linear region of the first transient stage, and the definite porous structure has been established before the end of the first transient stage. The self-ordering behavior of the porous film is influenced by the electrolyte concentration, film thickness and the applied current density. Great current density not only improves the cell arrangement order but also brings about larger cell dimension.

  18. Synthesis of methyl acetate from dimethyl ether using group VIII metal salts of phosphotungstic acid

    Energy Technology Data Exchange (ETDEWEB)

    Sardesai, A.; Lee, S.; Tartamella, T.

    2002-04-01

    Dimethyl ether (DME) can be produced much more efficiently in a single-stage, liquid-phase process from natural gas-based syngas as compared to the conventional process via dehydration of methanol. This process, based on dual catalysts slurried in inert oil, alleviates the chemical equilibrium limitation governing the methanol synthesis reaction and concurrently improves per-pass syngas conversion and reactor productivity. The potential, therefore, for production of methyl acetate via dimethyl ether carbonylation is of industrial importance. In the present study, conversion of dimethyl ether and carbon monoxide to methyl acetate is investigated over a variety of group VIII metal-substituted phosphotungstic acid salts. Experimental results of this catalytic reaction using rhodium, iridium, ruthenium, and palladium catalysts are evaluated and compared in terms of selectivity toward methyl acetate. The effects of active metal, support types, multiple metal loading, and feed conditions on carbonylation activity of DME are examined. Iridium metal substituted phosphotungstic acid supported on Davisil type 643 (pore size 150 A, surface area 279 m{sup 2}/g, mesh size 230-425) silica gel shows the highest activity for DME carbonylation. (author)

  19. Synthesis of highly ordered TiO2 nanotube in malonic acid solution by anodization.

    Science.gov (United States)

    Ryu, Won Hee; Park, Chan Jin; Kwon, Hyuk Sang

    2008-10-01

    We synthesized TiO2 nanotube array by anodizing in a solution of malonic acid (HOOCCH2COOH) and NH4F, and analyzed the morphology of the nanotube using scanning electron microscopy (SEM). The morphology of TiO2 nanotube was largely affected by anodizing time, anodizing voltage, and malonic acid concentration. With increasing the anodizing voltage from 5 V to 20 V, the diameter of TiO2 nanotube was increased from about 20 nm to 110 nm and its length from about 10 nm to 700 nm. In addition, the length of TiO2 nanotube was increased with increasing anodizing time up to 6 h at 20 V. We obtained the longest and the most highly ordered nanotube structure when anodizing Ti in a solution of 0.5 wt% NH4F and 1 M malonic acid at 20 V for 6 h.

  20. Tandem malonate-based glucosides (TMGs) for membrane protein structural studies

    DEFF Research Database (Denmark)

    Hussain, Hazrat; Mortensen, Jonas S.; Du, Yang

    2017-01-01

    class of glucoside amphiphiles, designated tandem malonate-based glucosides (TMGs). A few TMG agents proved effective at both stabilizing a range of membrane proteins and extracting proteins from the membrane environment. These favourable characteristics, along with synthetic convenience, indicate...

  1. Complete Oxidation of Propionate, Valerate, Succinate, and Other Organic Compounds by Newly Isolated Types of Marine, Anaerobic, Mesophilic, Gram-Negative, Sulfur-Reducing Eubacteria

    Science.gov (United States)

    Finster, Kai; Bak, Friedhelm

    1993-01-01

    Anaerobic enrichment cultures with either propionate, succinate, lactate, or valerate and elemental sulfur and inocula from shallow marine or deep-sea sediments were dominated by rod-shaped motile bacteria after three transfers. By application of deep-agar dilutions, five eubacterial strains were obtained in pure culture and designated Kyprop, Gyprop, Kysw2, Gylac, and Kyval. All strains were gram negative and grew by complete oxidation of the electron donors and concomitant stoichiometric reduction of elemental sulfur to hydrogen sulfide. The isolates used acetate, propionate, succinate, lactate, pyruvate, oxaloacetate, maleate, glutamate, alanine, aspartate, and yeast extract. All isolates, except strain Gylac, used citrate as an electron donor but valerate was oxidized only by strain Kyval. Fumarate and malate were degraded by all strains without an additional electron donor or acceptor. Kyprop, Gyprop, and Gylac utilized elemental sulfur as the sole inorganic electron acceptor, while Kysw2 and Kyval also utilized nitrate, dimethyl sulfoxide, or Fe(III)-citrate as an electron acceptor. Images PMID:16348934

  2. D Malone Travel Expenses 2010-2011Q3 ENGLISH.xlsx

    International Development Research Centre (IDRC) Digital Library (Canada)

    acray

    David M. Malone - President. Travel Expenses 2010-2011. Other. Travel. Other. Meals &. Expenses. Total. Amount. Net Expenses. Organization. Dates. Destination(s). Purpose. Airfare. Transportation. Hotels. Incidentals. (note 1). Expenses. Recovered. Paid by IDRC. Recovered from. April 7-8. Montreal. IDRC sponsored ...

  3. 2012-2013 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-2013 Expense report for David Malone. Download PDF of Expense Report 2012-2013 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  4. 2010-2011 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-2011 Expense report for David Malone. Download PDF of Expense Report 2010-2011 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  5. 2011-2012 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-2012 Expense report for David Malone. Download PDF of Expense Report 2011-2012 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  6. Determination of zinc by substoichiometric extraction with malonic anilide

    International Nuclear Information System (INIS)

    Dutta, J.; Basu, S.

    1994-01-01

    A substoichiometric radiochemical extraction method has been developed for the determination of zinc employing a new chelating agent e.g. malonic anilide, dissolved in a mixed organic solvent, MIBK and ether (3:1). The reagent was synthesized and characterized in our laboratory. The method developed was utilized to determine the zinc content in few common vegetable samples. (orig.)

  7. Synthesis and uses of the amides extractants

    International Nuclear Information System (INIS)

    Musikas, C.

    1989-01-01

    Carboxylic acids amides (RR'NCOCR''), malonic acid amides (RR'NCOCH 2 CONRR') and substituted malonic acid amides (RR'NCOCHR'' CONRR') are extractants of the actinides ions. They show good prospects for use in the nuclear industry because of their complete incinerability. In addition, their degradation products interfer much more less in the separation processes when compared with organophosphorus extractants. The synthesis and the purification of two typical extractants: N-N-di (2-ethylhexyl) butyramide (C 4 H 9 CHC 2 H 5 CH 2 ) 2 NCOC 3 H 7 and N,N'-dimethyl N,N'-dibutyl 1.3 diamide 2(3-oxa)nonyl propane (C 4 H 9 CH 3 NCO) 2 CHC 2 H 4 OC 6 H 13 are described. The purities, checked by NMR, elemental analysis and potentiometry, were in the range 98 to 99.5%. The yields for monoamides were in the range 70 to 90% and for the diamides 20 to 40%. 3 figs, 3 tabs, 10 refs

  8. The Succinated Proteome of FH-Mutant Tumours

    Directory of Open Access Journals (Sweden)

    Ming Yang

    2014-08-01

    Full Text Available Inherited mutations in the Krebs cycle enzyme fumarate hydratase (FH predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC. Loss of FH activity in HLRCC tumours causes accumulation of the Krebs cycle intermediate fumarate to high levels, which may act as an oncometabolite through various, but not necessarily mutually exclusive, mechanisms. One such mechanism, succination, is an irreversible non-enzymatic modification of cysteine residues by fumarate, to form S-(2-succinocysteine (2SC. Previous studies have demonstrated that succination of proteins including glyceraldehyde 3-phosphate dehydrogenase (GAPDH, kelch-like ECH-associated protein 1 (KEAP1 and mitochondrial aconitase (ACO2 can have profound effects on cellular metabolism. Furthermore, immunostaining for 2SC is a sensitive and specific biomarker for HLRCC tumours. Here, we performed a proteomic screen on an FH-mutant tumour and two HLRCC-derived cancer cell lines and identified 60 proteins where one or more cysteine residues were succinated; 10 of which were succinated at cysteine residues either predicted, or experimentally proven, to be functionally significant. Bioinformatic enrichment analyses identified most succinated targets to be involved in redox signaling. To our knowledge, this is the first proteomic-based succination screen performed in human tumours and cancer-derived cells and has identified novel 2SC targets that may be relevant to the pathogenesis of HLRCC.

  9. Comparative study of oxalic and malonic acid behaviour in the chemical cleaning of alloy 800 surfaces

    International Nuclear Information System (INIS)

    Garcia, Damian A.; Bruyere, Vivienne I.E.; Bordoni, Roberto A.; Olmedo, Ana M.; Morando, Pedro J.

    2004-01-01

    This work consisted, in a first stage, on a basic study of the dissolution mechanism of nickel ferrite in aqueous malonic acid. Powdered oxides (Ni x Fe 3-x O 4 ) were synthesized by wet procedures and heated at 750 C degrees. These oxides were characterized by conventional methods and dissolved under different experimental conditions (pH, reagent concentration, temperature, etc.) in order to determine the dissolution rates. Optimal dissolution conditions were explored and compared to the corresponding oxalic acid ones. In a second stage, these conditions were applied to oxides grown on Alloy 800 coupons. Before oxidation, all coupons were ground polished and then were exposed to hydrothermal conditions (350 C degrees, pH 25Cdegrees ≅ 10.4 -LiOH-, 20-22 days) in static autoclaves. Finally, oxidized and unoxidized coupons were treated with chemical solutions containing oxalic or malonic acid at conditions optimized in the first stage. These results were also compared to those obtained on coupons exposed to a commercial formulation, APAC (Alkaline Permanganate Ammonium Citrate), as a reference. The results on coupon descaling using APMAL (AP + Malonic), APOX (AP + oxalic) and the comparison with APAC leads to conclude that malonic acid is a reagent whose chemical behavior is much better than oxalic acid and comparable to commercial formulations. (author) [es

  10. A molecular dynamics calculation of solid phase of malonic acid

    Indian Academy of Sciences (India)

    Recent studies suggest that hydrogen bonds, in particular, hydrogen bond chains play an important role in determining the properties of a substance.We report an investigation into the triclinic phase of crystalline malonic acid. One of two intermolecular interaction potentials proposed here is seen to predict the lattice ...

  11. N-(4-Bromobenzyl-2-(5,6-dimethyl-1H-benzo[d]imid-azol-2-ylbenzeneamine

    Directory of Open Access Journals (Sweden)

    Monika Dziełak

    2018-01-01

    Full Text Available N-(4-Bromobenzyl-2-(5,6-dimethyl-1H-benzo[d]imidazol-2-ylbenzeneamine was obtained by condensation of N-(4-bromobenzyl-3,1-benzoxazine-2,4-dione (N-(4-bromobenzylisatoic anhydride with 4,5-dimethyl-1,2-phenylenediamine in refluxing acetic acid. This is a rare example of condensation of N-substituted 3,1-benzoxazine-2,4-dione with 1,2-phenylenediamine, which resulted in the formation of a benzimidazole derivative with a moderate yield. Crystallographic studies and initial biological screening were performed for the obtained product.

  12. 21 CFR 172.275 - Synthetic paraffin and succinic derivatives.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic paraffin and succinic derivatives. 172... FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.275 Synthetic paraffin and succinic derivatives. Synthetic paraffin and succinic derivatives identified in this section may be safely...

  13. Contribution to the study of carbohydrate radiolysis: study of the formation of malonic aldehyde during gamma irradiation of glucose

    International Nuclear Information System (INIS)

    Enrico, Gerard.

    1974-01-01

    It was shown that malonic aldehyde can be formed directly by radiation of dry glucose or through the radicals of water when the latter is present. The direct effect leads to a malonic aldehyde production proportional to the dose and independent of dose rate, temperature over a wide range, presence of oxygen and crystalline state of the glucose, but strongly dependent on the water content and anomeric form of the glucose. Isotopic labelling showed that both ends of the glucose molecule participate in the malonic aldehyde formation. Extrapolation to linear polymers (maltose, maltotriose) reveals the independence of the radiolysis yield with regard to the α 1-4 bond and suggests that it tends towards that of glucose in amylose. The indirect effect is linked with the action of the OH radicals of water and appears when glucose is irradiated in a sufficiently hydrated state or in solution. In the latter case the malonic aldehyde concentration is largely independent of the glucose concentration and is not proportional to the dose. Oxygen has little effect but a strong activation is observed at high pH. The use of 14 C showed that the aldehyde end of glucose is responsible for most of the malonic aldehyde. Polymerisation of the glucose by α 1-4 binding reduces the radiolytic yield. The indirect effect would thus be negligible in amylose [fr

  14. Low-Dissipation Thermosets Derived from Oligo(2,6-Dimethyl Phenylene Oxide-Containing Benzoxazines

    Directory of Open Access Journals (Sweden)

    Chien-Han Chen

    2018-04-01

    Full Text Available Poly(2,6-dimethyl phenyl oxide (PPO is known for its low dissipation factor. To achieve insulating materials with low dissipation factors for high-frequency communication applications, a telechelic oligomer-type benzoxazine (P-APPO and a main-chain type benzoxazine polymer (BPA-APPO were prepared from an amine end-capped oligo (2,6-dimethyl phenylene oxide (APPO. The APPO was prepared from a nucleophilic substitution of a phenol-end capped oligo (2,6-dimethyl phenylene oxide (a commercial product, SA 90 with fluoronitrobenzene, and followed by catalytic hydrogenation. After self-curing or curing with a dicyclopentadiene-phenol epoxy (HP 7200, thermosets with high-Tg and low-dissipation factor can be achieved. Furthermore, the resulting epoxy thermosets show better thermal and dielectric properties than those of epoxy thermoset cured from its precursor SA90, demonstrating it is a successful modification in simultaneously enhancing the thermal and dielectric properties.

  15. Microbiota-Produced Succinate Improves Glucose Homeostasis via Intestinal Gluconeogenesis

    DEFF Research Database (Denmark)

    De Vadder, Filipe; Kovatcheva-Datchary, Petia; Zitoun, Carine

    2016-01-01

    Beneficial effects of dietary fiber on glucose and energy homeostasis have long been described, focusing mostly on the production of short-chain fatty acids by the gut commensal bacteria. However, bacterial fermentation of dietary fiber also produces large amounts of succinate and, to date......, no study has focused on the role of succinate on host metabolism. Here, we fed mice a fiber-rich diet and found that succinate was the most abundant carboxylic acid in the cecum. Dietary succinate was identified as a substrate for intestinal gluconeogenesis (IGN), a process that improves glucose...

  16. Succinate Dehydrogenase Activity Assay in situ with Blue Tetrazolium Salt in Crabtree-Positive Saccharomyces cerevisiae Strain

    Directory of Open Access Journals (Sweden)

    Joanna Berlowska

    2008-01-01

    Full Text Available A spectrophotometric method for determining succinate dehydrogenase (SDH activity assay in azide-sensitive yeast Saccharomyces cerevisiae has been developed. The permeabilization of yeast cells by 0.05 % digitonin permitted to study yeast enzymatic activity in situ. The reduction of blue tetrazolium salt (BT to blue tetrazolium formazan (BTf was conducted in the presence of phenazine methosulphate (PMS as an exogenous electron carrier, and sodium azide (SA as an inhibitor of cytochrome oxidase (Cyt pathway. Various factors such as type of substrate, BT concentration, cell number, temperature and time of incubation, and different Cyt pathway blockers were optimized. In earlier studies, dimethyl sulfoxide (DMSO had been selected as the best solvent for extraction of BTf from yeast cells. The linear correlation between permeabilized yeast cell density and amount of formed formazan was evidenced in the range from 9·10^7 to 5·10^8 cells per sample solution. Below the yeast cell concentration of 10^7 the absorbance values were too low to detect formazans with good precision. This standarized procedure allows the estimation of SDH activity in whole cells, depending on vitality level of yeast populations. Significant increases of succinate dehydrogenase activities were observed in sequential passages as the result of the increase of activity of the strain and adaptation to cultivation conditions.

  17. Radiotracer studies on the formation of 2,5-dimethyl-4-hydroxy-3(2H)-furanone in detached ripening strawberry fruits

    International Nuclear Information System (INIS)

    Roscher, R.; Bringmann, G.; Schreier, P.; Schwab, W.

    1998-01-01

    The transformation of 12 radioactively labeled compounds into 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), glycosidically bound DMHF, and 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) was investigated in detached ripening strawberry fruits (Fragaria x ananassa) over a 3-day period. Radiochemical analysis of the different fruit parts revealed that major portions of the applied radioactivity (up to 66%) remained in the stems and calyx. Incorporation levels of [2- 14 C]-dihydroxyacetone, D-[1- 3 H]glucose, D-[U- 14 C]-glucose, D-[U- 14 C]glucose 6-phosphate, D-[U- 14 C]fructose, and D-[U- 14 C]fructose 1,6-bisphosphate into the total amount of furanone derivatives were 0.022, 0.032, 0.035, 0.147, 0.202, and 0.289% of the radioactivity entering the fruits, respectively. Minor amounts of radioactivity (0.001%) were detected in the furanone structures after the administration of [1- 14 C]acetate and [3- 14 C]pyruvate. L-[1- 14 C]Fucose, L-[6- 3 H]fucose, L-[1- 3 H]rhamnose, L-[U- 14 C]-threonine, L-[U- 14 C]lactaldehyde, and [2- 14 C]malonic acid were not transformed into DMHF or a derivative thereof. (author)

  18. BER-Myriant Succinic Acid Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Shmorhun, Mark [Myriant Lake Providence, Inc., Lake Providence, LA (United States)

    2015-12-31

    Myriant Corporation (Myriant) has successfully produced the bioproduct succinic acid by the fermentation of glucose at a commercial scale operation in Lake Providence, Louisiana. The MySAB facility (Myriant Succinic Acid Biorefinery) came on stream in May 2013 and has been producing product since then. The MySAB facility is a demonstration-scale plant, capable of utilizing sorghum grits and commercially available dextrose, to ferment glucose into succinic acid. A downstream processing train has demonstrated the ability to produce an industrial, a standard and a polymer grade product. It consists of cell separation, membrane filtration, continuous chromatography, polishing to remove ionic and color bodies impurities, and final evaporation and crystallization. A by-product of the process is ammonium sulfate which is sold as a liquid fertilizer product. Since 2007 when development work began in the Woburn, Massachusetts R&D laboratories, the succinic acid bio-process has evolved through: Process development (microbiology, fermentation, and downstream) – R&D development laboratories; Piloting efforts at Fermic S.A. de C.V., Mexico City, Mexico – upstream and downstream processes; Design, construction, commissioning, and commercial production operations at the MySAB facility Additionally, Myriant became a wholly-owned subsidiary of the PTT Global Chemical Plc., Thailand, in late 2015, their investment into and support of Myriant goes back to 2011. The support of PTT Global Chemical Plc. helped to improve the upstream and downstream processes, and produce significant metric ton quantities of high quality bio-based succinic acid. The product has gone into a number of commercial markets worldwide for customer applications, development and production. The experience base gained via operations at the MySAB facility since May 2013, along with continued R&D development efforts involving Microbiology, Fermentation, and Downstream processes, at both the Woburn, Massachusetts

  19. Organoruthenium (II) complexes produced by insertion reactions of substituted olefins into a hydrido-ruthenium bond

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, Katsuma; Sasada, Yoko; Kitamura, Tsuneyuki [Nagasaki Univ. (Japan)

    1980-04-01

    Dimethyl fumarate, 2-vinylpyridine, and acrylonitrile insert into a H-Ru bond of (RuClH(CO)(PPh/sub 3/)/sub 3/) (1) to yield new substituted alkylruthenium(II) complexes. Methyl sorbate also reacted with 1 to give a new substituted eta/sup 3/-allylruthenium(II) complex.

  20. The synthesis of 5-[1-11C]ethyl barbiturates from labelled malonic esters

    International Nuclear Information System (INIS)

    Gee, A.; Laangstroem, B.

    1991-01-01

    The synthesis of [ 11 C]phenobarbital, [ 11 C]pentobarbital and[ 11 C]amobarbital labelled in the 5-[1- 11 C]ethyl position is reported. The malonic esters R- CH(CO 2 Et) 2 [R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with [1- 11 C]ethyl iodide prepared from [ 11 C]carbon dioxide. Ring closure of the 2-[1- 11 C]ethyl-labelled malonic esters with urea afforded 5-[1- 11 C]ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from [ 11 C] carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) [ 11 C]carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author)

  1. Identification and Quantitation of Malonic Acid Biomarkers of In-Born Error Metabolism by Targeted Metabolomics

    Science.gov (United States)

    Ambati, Chandra Shekar R.; Yuan, Furong; Abu-Elheiga, Lutfi A.; Zhang, Yiqing; Shetty, Vivekananda

    2017-05-01

    Malonic acid (MA), methylmalonic acid (MMA), and ethylmalonic acid (EMA) metabolites are implicated in various non-cancer disorders that are associated with inborn-error metabolism. In this study, we have slightly modified the published 3-nitrophenylhydrazine (3NPH) derivatization method and applied it to derivatize MA, MMA, and EMA to their hydrazone derivatives, which were amenable for liquid chromatography- mass spectrometry (LC-MS) quantitation. 3NPH was used to derivatize MA, MMA, and EMA, and multiple reaction monitoring (MRM) transitions of the corresponding derivatives were determined by product-ion experiments. Data normalization and absolute quantitation were achieved by using 3NPH derivatized isotopic labeled compounds 13C2-MA, MMA-D3, and EMA-D3. The detection limits were found to be at nanomolar concentrations and a good linearity was achieved from nanomolar to millimolar concentrations. As a proof of concept study, we have investigated the levels of malonic acids in mouse plasma with malonyl-CoA decarboxylase deficiency (MCD-D), and we have successfully applied 3NPH method to identify and quantitate all three malonic acids in wild type (WT) and MCD-D plasma with high accuracy. The results of this method were compared with that of underivatized malonic acid standards experiments that were performed using hydrophilic interaction liquid chromatography (HILIC)-MRM. Compared with HILIC method, 3NPH derivatization strategy was found to be very efficient to identify these molecules as it greatly improved the sensitivity, quantitation accuracy, as well as peak shape and resolution. Furthermore, there was no matrix effect in LC-MS analysis and the derivatized metabolites were found to be very stable for longer time.

  2. Succinic acid production by escherichia coli under anaerobic fermentation

    International Nuclear Information System (INIS)

    El Shafey, H.M.; Meleigy, S.A.

    2009-01-01

    The effect of alteration of growth conditions, addition of different sodium salts, and irradiation by gamma rays on succinic acid production by E. coli was studied. Twenty one isolates were obtained from buffalo's rumen, and anaerobic screening of the isolated bacterial strains showed the abilities of seventeen strains to produce succinic acid. The two bacterial strains having highest succinic acid production were identified as escherichia coli SP9 and SP16, and were selected for further studies. Results showed that growth conditions yielded highest succinic acid production for the two isolates were: 72 hours incubation, 37 degree c incubation temperature, initial ph of the fermentation medium 6.0,and 3% (v/v)inoculum size. Addition of 5 mm of nine different sodium salts to the fermentation medium showed stimulating effect on succinic acid production of the nine tried sodium salts, sodium carbonate was found to have the highest enhancing effect, especially if used at 15 mm concentration. Gamma irradiation doses tried were in the range of (0.25-1.50 kGy). An enhancing effect on succinic acid production was shown in the range of 0.25-0.75 kGy with a maximal production at 0.75 kGy (giving 8.36% increase) for e.coli SP9, and in the range of 0.25-1.00 kGy with a maximal production at 1.0 kGy (7.60% increase) for e.coli SP16. higher gamma doses led to a decrease in the enhancing effect. An overall increase in the succinic acid yield of 79.45% and 94.26% for e. coli SP9 and SP16, respectively, was achieved in implicating all optimized factors for succinic acid production in one time

  3. Stoichiometry of mitochondrial H+ translocation coupled to succinate oxidation at level flow.

    Science.gov (United States)

    Costa, L E; Reynafarje, B; Lehninger, A L

    1984-04-25

    The mechanistic stoichiometry of vectorial H+ translocation coupled to succinate oxidation by rat liver mitochondria in the presence of a permeant cation has been determined under level flow conditions with a membraneless fast responding O2 electrode kinetically matched with a glass pH electrode. The reactions were initiated by rapid injection of O2 into the anaerobically preincubated test system under conditions in which interfering H+ backflow was minimized. The rates of O2 uptake and H+ ejection, obtained from computer-fitted regression lines, were monotonic and first order over 75% of the course of O2 consumption. Extrapolation of the observed rates to zero time, at which zero delta mu H+ and thus level flow prevails, yielded vectorial H+/O flow ratios above 7 and closely approaching 8. The mitochondria undergo no irreversible change and give identical H+/O ratios on repeated tests. In a further refinement, the lower and upper limits of the mechanistic H+/O ratio were determined to be 7.55 and 8.56, respectively, from plots of the rates of O2 uptake versus H+ ejection at increasing malonate and increasing valinomycin concentrations, respectively. It is therefore concluded that the mechanistic H+/O ratio for energy-conserving sites 2 + 3 is 8, in confirmation of earlier measurements. KCl concentration is critical for maximal observed H+/O ratios. Optimum conditions and possible errors in determination of mechanistic H+/O translocation ratios are discussed.

  4. Green Synthesis of Acid Esters from Furfural via Stobbe Condensation

    Directory of Open Access Journals (Sweden)

    Shubhra Banerjee

    2013-01-01

    Full Text Available Solvent-free Stobbe condensation of furfural 1 with dimethyl succinate 2 under anhydrous conditions at room temperature using dry-solid potassium tertiary butoxide gave 3-carbomethoxy, 4-furyl-3-butenoic acid 3, which upon methylation followed by Stobbe condensation reaction with different aldehydes and/or ketones under anhydrous conditions at room temperature afforded substituted carbomethoxy acids 5a–f. These acid ester products were saponified to the corresponding dicarboxylic acids 6a–f which are useful in the synthesis of photochromic fulgides.

  5. Fragrance material review on 2,2-dimethyl-3-phenylpropanol.

    Science.gov (United States)

    Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2,2-dimethyl-3-phenylpropanol when used as a fragrance ingredient is presented. 2,2-Dimethyl-3-phenylpropanol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a primary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group -C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-C-(R1)(R2)OH or Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2,2-dimethyl-3-phenylpropanol were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, phototoxicity, and photoallergy data. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Aryl Alkyl Alcohols in fragrances. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. 2-Amino-5-bromopyridinium hydrogen succinate

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2010-03-01

    Full Text Available In the title compound, C5H6BrN2+·C4H5O4−, the pyridine N atom of the 2-amino-5-bromopyridine molecule is protonated. The protonated N atom and the amino group are linked via N—H...O hydrogen bonds to the carboxylate O atoms of the singly deprotonated succinate anion. The hydrogen succinate anions are linked via O—H...O hydrogen bonds. A weak intermolecular C—H...O hydrogen bond is also observed.

  7. The effect of alpha-tocopheryl succinate on succinate respiration in rat liver mitochondria

    Czech Academy of Sciences Publication Activity Database

    Sobotka, O.; Drahota, Zdeněk; Kučera, O.; Endlicher, R.; Rauchová, Hana; Červinková, Z.

    2015-01-01

    Roč. 64, Suppl.5 (2015), S609-S615 ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : tocopheryl succinate * Complex II * liver * mitochondria * homogenate * hepatocytes Subject RIV: ED - Physiology Impact factor: 1.643, year: 2015

  8. EFFECT OF SUBSTITUTION POSITION OF HYDROXY GROUP AT BENZOIC ACID ON THE LUMINESCENT AND DEGRADATION PROPERTIES OF POLY[DI(CARBOXYPHENYL) SUCCINATE-co-SEBACIC ANHYDRIDE]S

    Institute of Scientific and Technical Information of China (English)

    Jun Fan; Hong-liang Jiang; Kang-jie Zhu

    2007-01-01

    In this work, two new diacids, di(m-carboxyphenyl) succinate (m-dCPS) and di(o-carboxyphenyl) succinate (o-dCPS), were synthesized by reaction of m-, o-hydroxy benzoic acid with succinic chloride, respectively. Their corresponding copolymers with sebacic acid (SA), P(m-dCPS:SA) and P(o-dCPS:SA), were prepared by melt copolycondensation and characterized by NMR, UV and DSC methods. Compared with inherently fluorescent poly[di(p-carboxyphenyl) succinateco-sebacic anhydride] (P(p-dCPS:SA)), P(m-dCPS:SA) and P(o-dCPS:SA) displayed different luminescent properties. P(m-dCPS:SA) could emit fluorescence under the excitation of both visible and UV light, while P(o-dCPS:SA) could only emit fluorescence when excited with UV light. Degradation rate of the two new copolyanhydrides increased with the increase of SA fraction in the copolymers. In addition, P(o-dCPS:SA) degraded more rapidly than P(m-dCPS:SA) with the same composition. Typical surface-degradation characteristics of these copolyanhydrides were observed.

  9. Succinate modulates Ca(2+) transient and cardiomyocyte viability through PKA-dependent pathway.

    Science.gov (United States)

    Aguiar, Carla J; Andrade, Vanessa L; Gomes, Enéas R M; Alves, Márcia N M; Ladeira, Marina S; Pinheiro, Ana Cristina N; Gomes, Dawidson A; Almeida, Alvair P; Goes, Alfredo M; Resende, Rodrigo R; Guatimosim, Silvia; Leite, M Fatima

    2010-01-01

    GPR91 is an orphan G-protein-coupled receptor (GPCR) that has been characterized as a receptor for succinate, a citric acid cycle intermediate, in several tissues. In the heart, the role of succinate is unknown. We now report that rat ventricular cardiomyocytes express GPR91. We found that succinate, through GPR91, increases the amplitude and the rate of decline of global Ca(2+) transient, by increasing the phosphorylation levels of ryanodine receptor and phospholamban, two well known Ca(2+) handling proteins. The effects of succinate on Ca(2+) transient were abolished by pre-treatment with adenylyl cyclase and cAMP-dependent protein kinase (PKA) inhibitors. Direct PKA activation by succinate was further confirmed using a FRET-based A-kinase activity reporter. Additionally, succinate decreases cardiomyocyte viability through a caspase-3 activation pathway, effect also prevented by PKA inhibition. Taken together, these observations show that succinate acts as a signaling molecule in cardiomyocytes, modulating global Ca(2+) transient and cell viability through a PKA-dependent pathway. 2009 Elsevier Ltd. All rights reserved.

  10. Acylation of lithiated trimethylsilyl malonates and esters applied to the synthesis of molecules of biological interest, labelled with carbon 14

    International Nuclear Information System (INIS)

    Gorichon, Liliane

    1978-01-01

    This research thesis first reports an attempt to generalise the method of acylation of lithiated trimethylsilyl (TMS) malonates by introduction of new organic functions into the radical. This leads to the synthesis of some alkaloids such as nicotine and contine. The author also shows that fat acids can be labelled with carbon 14 in any position of the carbon chain. Thus, acylation of these malonates have been performed by using different acid chlorides. Then, the author reports attempts to simplify this method by using α-lithiated trimethylsilyl esters instead of malonates. He reports attempts of acylation of TMS isobutyrate, TMS proprionate and TMS acetate, by using different radioactive acid chlorides (benzoyl chloride, nicotinoyl chloride, lauryl chloride, and oleyl chloride). The author finally shows that both methods are equivalent by synthesising muscalure from TMS butylmalonate as well as from TMS hexanoate

  11. The synthesis of 5-(1- sup 11 C)ethyl barbiturates from labelled malonic esters

    Energy Technology Data Exchange (ETDEWEB)

    Gee, A.; Laangstroem, B. (Uppsala Univ. (Sweden). Dept. of Organic Chemistry)

    1991-01-01

    The synthesis of ({sup 11}C)phenobarbital, ({sup 11}C)pentobarbital and({sup 11}C)amobarbital labelled in the 5-(1-{sup 11}C)ethyl position is reported. The malonic esters R- CH(CO{sub 2}Et){sub 2} R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with (1-{sup 11}C)ethyl iodide prepared from ({sup 11}C)carbon dioxide. Ring closure of the 2-(1-{sup 11}C)ethyl-labelled malonic esters with urea afforded 5-(1-{sup 11}C)ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from ({sup 11}C) carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) ({sup 11}C)carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author).

  12. Industrial systems biology of Saccharomyces cerevisiae enables novel succinic acid cell factory.

    Directory of Open Access Journals (Sweden)

    José Manuel Otero

    Full Text Available Saccharomyces cerevisiae is the most well characterized eukaryote, the preferred microbial cell factory for the largest industrial biotechnology product (bioethanol, and a robust commerically compatible scaffold to be exploitted for diverse chemical production. Succinic acid is a highly sought after added-value chemical for which there is no native pre-disposition for production and accmulation in S. cerevisiae. The genome-scale metabolic network reconstruction of S. cerevisiae enabled in silico gene deletion predictions using an evolutionary programming method to couple biomass and succinate production. Glycine and serine, both essential amino acids required for biomass formation, are formed from both glycolytic and TCA cycle intermediates. Succinate formation results from the isocitrate lyase catalyzed conversion of isocitrate, and from the α-keto-glutarate dehydrogenase catalyzed conversion of α-keto-glutarate. Succinate is subsequently depleted by the succinate dehydrogenase complex. The metabolic engineering strategy identified included deletion of the primary succinate consuming reaction, Sdh3p, and interruption of glycolysis derived serine by deletion of 3-phosphoglycerate dehydrogenase, Ser3p/Ser33p. Pursuing these targets, a multi-gene deletion strain was constructed, and directed evolution with selection used to identify a succinate producing mutant. Physiological characterization coupled with integrated data analysis of transcriptome data in the metabolically engineered strain were used to identify 2(nd-round metabolic engineering targets. The resulting strain represents a 30-fold improvement in succinate titer, and a 43-fold improvement in succinate yield on biomass, with only a 2.8-fold decrease in the specific growth rate compared to the reference strain. Intuitive genetic targets for either over-expression or interruption of succinate producing or consuming pathways, respectively, do not lead to increased succinate. Rather, we

  13. Radioiodinated phenylalkyl malonic acid derivatives as pH-sensitive SPECT tracers.

    Directory of Open Access Journals (Sweden)

    Matthias Bauwens

    Full Text Available INTRODUCTION: In vivo pH imaging has been a field of interest for molecular imaging for many years. This is especially important for determining tumor acidity, an important driving force of tumor invasion and metastasis formation, but also in the process of apoptosis. METHODS: 2-(4-[(123I]iodophenethyl-2-methylmalonic acid (IPMM, 2-(4-[(123I]iodophenethyl-malonic acid (IPM, 2-(4-[(123I]iodobenzyl-malonic acid (IBMM and 4-[(123I]iodophthalic acid (IP were radiolabeled via the Cu(+ isotopic nucleophilic exchange method. All tracers were tested in vitro in buffer systems to assess pH driven cell uptake. In vivo biodistribution of [(123I]IPMM and [(123I]IPM was determined in healthy mice and the pH targeting efficacy in vivo of [(123I]IPM was evaluated in an anti-Fas monoclonal antibody (mAb apoptosis model. In addition a mouse RIF-1 tumor model was explored in which tumor pH was decreased from 7.0 to 6.5 by means of induction of hyperglycemia in combination with administration of meta-iodobenzylguanidine. RESULTS: Radiosynthesis resulted in 15-20% for iodo-bromo exchange and 50-60% yield for iodo-iodo exchange while in vitro experiments showed a pH-sensitive uptake for all tracers. Shelf-life stability and in vivo stability was excellent for all tracers. [(123I]IPMM and [(123I]IPM showed a moderately fast predominantly biliary clearance while a high retention was observed in blood. The biodistribution profile of [(123I]IPM was found to be most favorable in view of pH-specific imaging. [(123I]IPM showed a clear pH-related uptake pattern in the RIF-1 tumor model. CONCLUSION: Iodine-123 labeled malonic acid derivates such as [(123I]IPM show a clearly pH dependent uptake in tumor cells both in vitro and in vivo which allows to visualize regional acidosis. However, these compounds are not suitable for detection of apoptosis due to a poor acidosis effect.

  14. Recovery of succinic acid produced by fermentation of a metabolically engineered Mannheimia succiniciproducens strain.

    Science.gov (United States)

    Song, Hyohak; Huh, Yun Suk; Lee, Sang Yup; Hong, Won Hi; Hong, Yeon Ki

    2007-12-01

    There have recently been much advances in the production of succinic acid, an important four-carbon dicarboxylic acid for many industrial applications, by fermentation of several natural and engineered bacterial strains. Mannheimia succiniciproducens MBEL55E isolated from bovine rumen is able to produce succinic acid with high efficiency, but also produces acetic, formic and lactic acids just like other anaerobic succinic acid producers. We recently reported the development of an engineered M. succiniciproducens LPK7 strain which produces succinic acid as a major fermentation product while producing much reduced by-products. Having an improved succinic acid producer developed, it is equally important to develop a cost-effective downstream process for the recovery of succinic acid. In this paper, we report the development of a simpler and more efficient method for the recovery of succinic acid. For the recovery of succinic acid from the fermentation broth of LPK7 strain, a simple process composed of a single reactive extraction, vacuum distillation, and crystallization yielded highly purified succinic acid (greater than 99.5% purity, wt%) with a high yield of 67.05wt%. When the same recovery process or even multiple reactive extraction steps were applied to the fermentation broth of MBEL55E, lower purity and yield of succinic acid were obtained. These results suggest that succinic acid can be purified in a cost-effective manner by using the fermentation broth of engineered LPK7 strain, showing the importance of integrating the strain development, fermentation and downstream process for optimizing the whole processes for succinic acid production.

  15. The Influence of Substituents on the Tautomerism of Symmetrically Substituted 2,2'-Bis-benzimidazoles

    Directory of Open Access Journals (Sweden)

    Dall'Oglio Evandro

    2002-01-01

    Full Text Available The tautomerism of five symmetrically substituted 2,2'-bis-benzimidazoles [5(6,5'(6'-tetramethyl- (1; 5(6,5'(6'-dimethyl-(2; 5(6,5'(6'-dichloro- (3; 5(6,5'(6'-dimethoxy- (4 and 4(7,4'(7'-dimethyl-2,2'-bis-benzimidazole (5], was studied by means of ¹H NMR spectroscopy at variable temperatures, and the influence of the substituents on the energy barriers for tautomeric interconversion was interpreted with the aid of theoretical calculations.

  16. Effective reduction in the nanoparticle sizes of NiO obtained via the pyrolysis of nickel malonate precursor modified using oleylamine surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Lontio Fomekong, Roussin, E-mail: lonforou@yahoo.fr [Chemistry Department, Higher Teacher Training College, University of Yaoundé I, B.P. 47, Yaoundé (Cameroon); Institut de la Matière Condensée et des Nanosciences, Université Catholique de Louvain, Croix du Sud 1, 1348 Louvain-La-Neuve (Belgium); Ngolui Lambi, John; Ebede, Guy Roland [Chemistry Department, Higher Teacher Training College, University of Yaoundé I, B.P. 47, Yaoundé (Cameroon); Kenfack Tsobnang, Patrice [Chemistry Department, University of Dschang, PO Box 96, Dschang (Cameroon); Tedjieukeng Kamta, Hypolite Mathias; Ngnintedem Yonti, Cedrik [Chemistry Department, Higher Teacher Training College, University of Yaoundé I, B.P. 47, Yaoundé (Cameroon); Delcorte, Arnaud [Institut de la Matière Condensée et des Nanosciences, Université Catholique de Louvain, Croix du Sud 1, 1348 Louvain-La-Neuve (Belgium)

    2016-09-15

    Nickel oxide nanoparticles were synthesized via thermal decomposition of two precursors, the first, a simple nickel malonate and the second, a nickel malonate modified by oleylamine, a surfactant, both having been synthesized by precipitation. While FTIR, TGA and ToF-SIMS were used to characterize the two precursors and to show the presence of oleylamine in the modified precursor, XRD, SEM, TEM and BET were employed to investigate the structure, the morphology and the specific surface area of the decomposition products obtained after pyrolysis. The results showed that the modification of nickel malonate by oleylamine was effective. The XRD results, which showed a cubic structure for the NiO obtained, suggest with SEM an important particle size reduction (at least 54%) when oleylamine was used to modify the nickel malonate precursor. The SEM images also showed a well-defined spherical nanoparticle morphology in both cases, not affected by the presence of oleylamine. The TEM also confirmed the reduction of particle size and their spherical nature but at the same time showed that, in the presence of oleylamine, there was no agglomeration resulting in a more uniform particle size distribution. The specific surface area of the NiO obtained by the oleylamine-modified precursor was 4.7 times larger than that obtained with the regular precursor. This again confirms the particle size reduction. - Highlights: • Nickel malonate precursor has been synthesized by precipitation method. • This precursor was successfully modified by a surfactant (oleylamine). • NiO was identified as the decomposition products of the previous precursors. • Oleylamine has provoked around 54% of particle size reduction of the NiO.

  17. The Path of Carbon in Photosynthesis VIII. The Role of Malic Acid

    Science.gov (United States)

    Bassham, James A.; Benson, Andrew A.; Calvin, Melvin

    1950-01-25

    Malonate has been found to inhibit the formation of malic acid during short periods of photosynthesis with radioactive carbon dioxide. This result, together with studies which show the photosynthetic cycle to be operating normally at the same time, indicates that malic acid is not an intermediate in photosynthesis but is probably closely related to some intermediate of the cycle. Absence of labeled succinic and fumaric acids in these experiments, in addition to the failure of malonate to inhibit photosynthesis, precludes the participation of these acids as intermediates in photosynthesis.

  18. Improvement of succinate production by release of end-product inhibition in Corynebacterium glutamicum.

    Science.gov (United States)

    Chung, Soon-Chun; Park, Joon-Song; Yun, Jiae; Park, Jin Hwan

    2017-03-01

    Succinate is a renewable-based platform chemical that may be used to produce a wide range of chemicals including 1,4-butanediol, tetrahydrofurane, and γ-butyrolactone. However, industrial fermentation of organic acids is often subject to end-product inhibition, which significantly retards cell growth and limits metabolic activities and final productivity. In this study, we report the development of metabolically engineered Corynebacterium glutamicum for high production of succinate by release of end-product inhibition coupled with an increase of key metabolic flux. It was found that the rates of glucose consumption and succinate production were significantly reduced by extracellular succinate in an engineered strain, S003. To understand the mechanism underlying the inhibition by succinate, comparative transcriptome analysis was performed. Among the downregulated genes, overexpression of the NCgl0275 gene was found to suppress the inhibition of glucose consumption and succinate production, resulting in a 37.7% increase in succinate production up to 55.4g/L in fed-batch fermentation. Further improvement was achieved by increasing the metabolic flux from PEP to OAA. The final engineered strain was able to produce 152.2g/L succinate, the highest production reported to date, with a yield of 1.1g/g glucose under anaerobic condition. These results suggest that the release of end-product inhibition coupled with an increase in key metabolic flux is a promising strategy for enhancing production of succinate. Copyright © 2017. Published by Elsevier Inc.

  19. An efficient method for synthesis of succinate-based MMP inhibitors.

    Science.gov (United States)

    Sibi, Mukund P; Hasegawa, Hikaru

    2002-10-03

    A differentially protected fumarate undergoes radical addition followed by allylstannane trapping to provide disubstituted succinates in good yields and high anti diastereoselectivity. The conversion of the succinate to a known MMP inhibitor has been accomplished. [reaction: see text

  20. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s bearing functionalizable carbonate building blocks: II. Enzymatic biodegradation and in vitro biocompatibility assay.

    Science.gov (United States)

    Yang, Jing; Tian, Weisheng; Li, Qiaobo; Li, Yang; Cao, Amin

    2004-01-01

    In a previous study, we have reported chemical synthesis of novel aliphatic poly(butylene succinate-co-cyclic carbonate) P(BS-co-CC)s bearing various functionalizable carbonate building blocks, and this work will continue to present our new studies on their enzymatic degradation and in vitro cell biocompatibility assay. First, enzymatic degradation of the novel P(BS-co-CC) film samples was investigated with two enzymes of lipase B Candida Antartic (Novozyme 435) and lipase Porcine Pancreas PPL, and it was revealed that copolymerizing linear poly(butylene succinate) PBS with a functionalizable carbonate building block could remarkably accelerate the enzymatic degradation of a synthesized product P(BS-co-CC), and its biodegradation behavior was found to strongly depend on the overall impacts of several important factors as the cyclic carbonate (CC) comonomer structure and molar content, molar mass, thermal characteristics, morphology, the enzyme-substrate specificity, and so forth. Further, the biodegraded residual film samples and water-soluble enzymatic degradation products were allowed to be analyzed by means of proton nuclear magnetic resonance (1H NMR), gel permeation chromatograph (GPC), differential scanning calorimeter (DSC), attenuated total reflection FTIR (ATR-FTIR), scanning electron microscope (SEM), and liquid chromatograph-mass spectrometry (LC-MS). On the experimental evidences, an exo-type mechanism of enzymatic chain hydrolysis preferentially occurring in the noncrystalline domains was suggested for the synthesized new P(BS-co-CC) film samples. With regard to their cell biocompatibilities, an assay with NIH 3T3 mouse fibroblast cell was conducted using the novel synthesized P(BS-co-CC) films as substrates with respect to the cell adhesion and proliferation, and these new biodegradable P(BS-co-CC) samples were found to exhibit as low cell toxicity as the PLLA control, particularly the two samples of poly(butylene succinate-co-18.7 mol % dimethyl

  1. Reductive Leaching Kinetics of Low Grade Manganese Deposits in H2SO4 Solution Using Malonic Acid as Reducing Agent

    OpenAIRE

    Taysser Lasheen; S. A. Abu Elenein; W. A. Saleh; A. H Orabi; D. A Ismaiel

    2014-01-01

    A leaching process was developed to extract manganese and metal values from Alloga manganese concentrate. The preferential leaching process was achieved through reductive leaching in dilute sulfuric acid medium with malonic acid as the reducing agent. Leaching parameters were optimized as 1.0 M H2SO4, 10% malonic acid in solid/liquid ratio 1:10 for 90 min at 80 C and using ore ground to – 74 µm. Under these conditions, the leaching efficiency of manganese reaches 97%, whilst iron dissolution ...

  2. Succinate dehydrogenase assembly factor 2 is needed for assembly and activity of mitochondrial complex II and for normal root elongation in Arabidopsis.

    Science.gov (United States)

    Huang, Shaobai; Taylor, Nicolas L; Ströher, Elke; Fenske, Ricarda; Millar, A Harvey

    2013-02-01

    Mitochondria complex II (succinate dehydrogenase, SDH) plays a central role in respiratory metabolism as a component of both the electron transport chain and the tricarboxylic acid cycle. We report the identification of an SDH assembly factor by analysis of T-DNA insertions in At5g51040, a protein with unknown function that was identified by mass spectrometry analysis as a low abundance mitochondrial protein. This gene is co-expressed with a number of genes encoding mitochondrial proteins, including SDH1-1, and has low partial sequence similarity to human SDHAF2, a protein required for flavin-adenine dinucleotide (FAD) insertion into SDH. In contrast to observations of other SDH deficient lines in Arabidopsis, the sdhaf2 line did not affect photosynthetic rate or stomatal conductance, but instead showed inhibition of primary root elongation with early lateral root emergence, presumably due to the low SDH activity caused by the reduced abundance of SDHAF2. Both roots and leaves showed succinate accumulation but different responses in the abundance of other organic acids and amino acids assayed. Isolated mitochondria showed lowered SDH1 protein abundance, lowered maximal SDH activity and less protein-bound flavin-adenine dinucleotide (FAD) at the molecular mass of SDH1 in the gel separation. The short root phenotype and SDH function of sdhaf2 was fully complemented by transformation with SDHAF2. Application of the SDH inhibitor, malonate, phenocopied the sdhaf2 root architecture in WT. Whole root respiratory assays showed no difference between WT and sdhaf2, but micro-respirometry of the tips of roots clearly showed low oxygen consumption in sdhaf2 which could explain a metabolic deficit responsible for root tip growth. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

  3. TREATMENT OF CHRONIC HEART FAILURE: FOCUS ON METOPROLOL SUCCINATE

    Directory of Open Access Journals (Sweden)

    O. D. Ostroumova

    2012-01-01

    Full Text Available Advantages of metoprolol succinate in patients with chronic heart failure (CHF are covered. Results of MERIT-HF study are taken as the main evidences. Patterns of the metoprolol succinate use in the treatment of different categories of patients with CHF (women, the elderly , severe CHF forms, CHF with concomitant hypertension or diabetes are considered.

  4. TREATMENT OF CHRONIC HEART FAILURE: FOCUS ON METOPROLOL SUCCINATE

    Directory of Open Access Journals (Sweden)

    O. D. Ostroumova

    2015-12-01

    Full Text Available Advantages of metoprolol succinate in patients with chronic heart failure (CHF are covered. Results of MERIT-HF study are taken as the main evidences. Patterns of the metoprolol succinate use in the treatment of different categories of patients with CHF (women, the elderly , severe CHF forms, CHF with concomitant hypertension or diabetes are considered.

  5. Temperature shift experiments suggest that metabolic impairment and enhanced rates of photorespiration decrease organic acid levels in soybean leaflets exposed to supra-optimal growth temperatures

    Science.gov (United States)

    Citrate, malate, malonate, fumarate and succinate in soybean leaflets decreased 40 to 80% when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Glycerate was not temperature responsive in this study. Temperature effects on the above mentioned organi...

  6. Self-ordering behavior of nanoporous anodic aluminum oxide (AAO) in malonic acid anodization

    International Nuclear Information System (INIS)

    Lee, W; Nielsch, K; Goesele, U

    2007-01-01

    The self-ordering behavior of anodic aluminum oxide (AAO) has been investigated for anodization of aluminum in malonic acid (H 4 C 3 O 4 ) solution. In the present study it is found that a porous oxide layer formed on the surface of aluminum can effectively suppress catastrophic local events (such as breakdown of the oxide film and plastic deformation of the aluminum substrate), and enables stable fast anodic oxidation under a high electric field of 110-140 V and ∼100 mA cm -2 . Studies on the self-ordering behavior of AAO indicated that the cell homogeneity of AAO increases dramatically as the anodization voltage gets higher than 120 V. Highly ordered AAO with a hexagonal arrangement of the nanopores could be obtained in a voltage range 125-140 V. The current density (i.e., the electric field strength (E) at the bottom of a pore) is an important parameter governing the self-ordering of the nanopores as well as the interpore distance (D int ) for a given anodization potential (U) during malonic acid anodization

  7. Formation of itraconazole-succinic acid cocrystals by gas antisolvent cocrystallization.

    Science.gov (United States)

    Ober, Courtney A; Gupta, Ram B

    2012-12-01

    Cocrystals of itraconazole, an antifungal drug with poor bioavailability, and succinic acid, a water-soluble dicarboxylic acid, were formed by gas antisolvent (GAS) cocrystallization using pressurized CO(2) to improve itraconazole dissolution. In this study, itraconazole and succinic acid were simultaneously dissolved in a liquid solvent, tetrahydrofuran, at ambient conditions. The solution was then pressurized with CO(2), which decreased the solvating power of tetrahydrofuran and caused crystallization of itraconazole-succinic acid cocrystals. The cocrystals prepared by GAS cocrystallization were compared to those produced using a traditional liquid antisolvent, n-heptane, for crystallinity, chemical structure, thermal behavior, size and surface morphology, potential clinical relevance, and stability. Powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy analyses showed that itraconazole-succinic acid cocrystals with physical and chemical properties similar to cocrystals produced using a traditional liquid antisolvent technique can be prepared by CO(2) antisolvent cocrystallization. The dissolution profile of itraconazole was significantly enhanced through GAS cocrystallization with succinic acid, achieving over 90% dissolution in less than 2 h. The cocrystals appeared stable against thermal stress for up to 4 weeks under accelerated stability conditions, showing only moderate decreases in their degree of crystallinity but no change in their crystalline structure. This study shows the utility of an itraconazole-succinic acid cocrystal for improving itraconazole bioavailability while also demonstrating the potential for CO(2) to replace traditional liquid antisolvents in cocrystal preparation, thus making cocrystal production more environmentally benign and scale-up more feasible.

  8. Fermentative Succinate Production: An Emerging Technology to Replace the Traditional Petrochemical Processes

    Directory of Open Access Journals (Sweden)

    Yujin Cao

    2013-01-01

    Full Text Available Succinate is a valuable platform chemical for multiple applications. Confronted with the exhaustion of fossil energy resources, fermentative succinate production from renewable biomass to replace the traditional petrochemical process is receiving an increasing amount of attention. During the past few years, the succinate-producing process using microbial fermentation has been made commercially available by the joint efforts of researchers in different fields. In this review, recent attempts and experiences devoted to reduce the production cost of biobased succinate are summarized, including strain improvement, fermentation engineering, and downstream processing. The key limitations and challenges faced in current microbial production systems are also proposed.

  9. Progress of succinic acid production from renewable resources: Metabolic and fermentative strategies.

    Science.gov (United States)

    Jiang, Min; Ma, Jiangfeng; Wu, Mingke; Liu, Rongming; Liang, Liya; Xin, Fengxue; Zhang, Wenming; Jia, Honghua; Dong, Weiliang

    2017-12-01

    Succinic acid is a four-carbon dicarboxylic acid, which has attracted much interest due to its abroad usage as a precursor of many industrially important chemicals in the food, chemicals, and pharmaceutical industries. Facing the shortage of crude oil supply and demand of sustainable development, biological production of succinic acid from renewable resources has become a topic of worldwide interest. In recent decades, robust producing strain selection, metabolic engineering of model strains, and process optimization for succinic acid production have been developed. This review provides an overview of succinic acid producers and cultivation technology, highlight some of the successful metabolic engineering approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Study of the radiolysis of succinic acid - applications in the dosimetry of high doses

    International Nuclear Information System (INIS)

    Andrade e Silva, L.G.

    1978-01-01

    A study is made of the effect of the gama radiation dose and of particle size of succinic acid (fine powder of large crystals) in relation with the formation of CO 2 and CO + H 2 , which are the main gaseous products of radiolysis. A different yield of CO + H 2 is found when the succinic acid is used as powder compared to the material in the form of large crystals. The reason for this difference is searched, studying the influence of heating and sublimation of the succinic acid prior to irradiation. The influence, in the mentioned yield, of the surface area of succinic acid particles, of the presence of oxygen (air) and of the rapid recrystallization of the acid are also studied. The formation of intermediate species in the radiolysis of succinic acid is examined. The system used in ethanol-succinic acid at 77K. Analysis are made using an electronic paramagnetic resonance spectrometer. The possibility of using succinic acid as a dosimeter for high level gama radiation doses is discussed [pt

  11. Bio-succinic acid production: Escherichia coli strains design from genome-scale perspectives

    Directory of Open Access Journals (Sweden)

    Bashir Sajo Mienda

    2017-10-01

    Full Text Available Escherichia coli (E. coli has been established to be a native producer of succinic acid (a platform chemical with different applications via mixed acid fermentation reactions. Genome-scale metabolic models (GEMs of E. coli have been published with capabilities of predicting strain design strategies for the production of bio-based succinic acid. Proof-of-principle strains are fundamentally constructed as a starting point for systems strategies for industrial strains development. Here, we review for the first time, the use of E. coli GEMs for construction of proof-of-principles strains for increasing succinic acid production. Specific case studies, where E. coli proof-of-principle strains were constructed for increasing bio-based succinic acid production from glucose and glycerol carbon sources have been highlighted. In addition, a propose systems strategies for industrial strain development that could be applicable for future microbial succinic acid production guided by GEMs have been presented.

  12. Citrate and malonate increase microbial activity and alter microbial community composition in uncontaminated and diesel-contaminated soil microcosms

    Science.gov (United States)

    Martin, Belinda C.; George, Suman J.; Price, Charles A.; Shahsavari, Esmaeil; Ball, Andrew S.; Tibbett, Mark; Ryan, Megan H.

    2016-09-01

    Petroleum hydrocarbons (PHCs) are among the most prevalent sources of environmental contamination. It has been hypothesized that plant root exudation of low molecular weight organic acid anions (carboxylates) may aid degradation of PHCs by stimulating heterotrophic microbial activity. To test their potential implication for bioremediation, we applied two commonly exuded carboxylates (citrate and malonate) to uncontaminated and diesel-contaminated microcosms (10 000 mg kg-1; aged 40 days) and determined their impact on the microbial community and PHC degradation. Every 48 h for 18 days, soil received 5 µmol g-1 of (i) citrate, (ii) malonate, (iii) citrate + malonate or (iv) water. Microbial activity was measured daily as the flux of CO2. After 18 days, changes in the microbial community were assessed by a community-level physiological profile (CLPP) and 16S rRNA bacterial community profiles determined by denaturing gradient gel electrophoresis (DGGE). Saturated PHCs remaining in the soil were assessed by gas chromatography-mass spectrometry (GC-MS). Cumulative soil respiration increased 4- to 6-fold with the addition of carboxylates, while diesel contamination resulted in a small, but similar, increase across all carboxylate treatments. The addition of carboxylates resulted in distinct changes to the microbial community in both contaminated and uncontaminated soils but only a small increase in the biodegradation of saturated PHCs as measured by the n-C17 : pristane biomarker. We conclude that while the addition of citrate and malonate had little direct effect on the biodegradation of saturated hydrocarbons present in diesel, their effect on the microbial community leads us to suggest further studies using a variety of soils and organic acids, and linked to in situ studies of plants, to investigate the role of carboxylates in microbial community dynamics.

  13. Bio-oil based biorefinery strategy for the production of succinic acid

    Science.gov (United States)

    2013-01-01

    Background Succinic acid is one of the key platform chemicals which can be produced via biotechnology process instead of petrochemical process. Biomass derived bio-oil have been investigated intensively as an alternative of diesel and gasoline fuels. Bio-oil could be fractionized into organic phase and aqueous phase parts. The organic phase bio-oil can be easily upgraded to transport fuel. The aqueous phase bio-oil (AP-bio-oil) is of low value. There is no report for its usage or upgrading via biological methods. In this paper, the use of AP-bio-oil for the production of succinic acid was investigated. Results The transgenic E. coli strain could grow in modified M9 medium containing 20 v/v% AP-bio-oil with an increase in OD from 0.25 to 1.09. And 0.38 g/L succinic acid was produced. With the presence of 4 g/L glucose in the medium, succinic acid concentration increased from 1.4 to 2.4 g/L by addition of 20 v/v% AP-bio-oil. When enzymatic hydrolysate of corn stover was used as carbon source, 10.3 g/L succinic acid was produced. The obtained succinic acid concentration increased to 11.5 g/L when 12.5 v/v% AP-bio-oil was added. However, it decreased to 8 g/L when 50 v/v% AP-bio-oil was added. GC-MS analysis revealed that some low molecular carbon compounds in the AP-bio-oil were utilized by E. coli. Conclusions The results indicate that AP-bio-oil can be used by E. coli for cell growth and succinic acid production. PMID:23657107

  14. Temperature-dependent deliquescence relative humidities and water activities using humidity controlled thermogravimetric analysis with application to malonic acid.

    Science.gov (United States)

    Beyer, Keith D; Schroeder, Jason R; Kissinger, Jared A

    2014-04-03

    We utilize a new experimental technique, humidity-controlled thermogravimetric analysis (HTGA), to determine temperature-dependent deliquescence relative humidities (DRH) and to determine the equilibrium concentration of a solution at a given temperature and relative humidity. To that end, we have investigated the malonic acid/water system determining the DRH and concentration/RH relationship in the temperature range 303-278 K. Excellent agreement is found with literature values for the DRH of malonic acid as a function of temperature and for the concentration/RH relationship at several temperatures. Thus, we extend the DRH and concentration/RH relationship to a broader temperature range and are using the HTGA experiments to investigate other organic acids.

  15. Succinic acid production from xylose mother liquor by recombinant Escherichia coli strain.

    Science.gov (United States)

    Wang, Honghui; Pan, Jiachuan; Wang, Jing; Wang, Nan; Zhang, Jie; Li, Qiang; Wang, Dan; Zhou, Xiaohua

    2014-11-02

    Succinic acid (1,4-butanedioic acid) is identified as one of important building-block chemicals. Xylose mother liquor is an abundant industrial residue in xylitol biorefining industry. In this study, xylose mother liquor was utilized to produce succinic acid by recombinant Escherichia coli strain SD121, and the response surface methodology was used to optimize the fermentation media. The optimal conditions of succinic acid fermentation were as follows: 82.62 g L -1 total initial sugars, 42.27 g L -1 MgCO 3 and 17.84 g L -1 yeast extract. The maximum production of succinic acid was 52.09 ± 0.21 g L -1 after 84 h with a yield of 0.63 ± 0.03 g g -1 total sugar, approaching the predicted value (53.18 g L -1 ). It was 1.78-fold of the production of that obtained with the basic medium. This was the first report on succinic acid production from xylose mother liquor by recombinant E. coli strains with media optimization using response surface methodology. This work suggested that the xylose mother liquor could be an alternative substrate for the economical production of succinic acid by recombinant E. coli strains.

  16. Vitamin E Succinate as an Adjuvant for Dendritic Cell Based Vaccines

    National Research Council Canada - National Science Library

    Ramanathapuram, Lalitha

    2004-01-01

    .... In this study we have employed Vitamin E succinate also known as alpha-tocopheryl succinate (alpha-TOS), a non-toxic esterified analogue of Vitamin E, as an adjuvant to enhance the effectiveness of DC vaccines in treating established murine mammary...

  17. Characterization of the respiratory chain of Helicobacter pylori

    DEFF Research Database (Denmark)

    Chen, M; Andersen, L P; Zhai, L

    1999-01-01

    reductase was inhibited by antimycin, implying the presence of a classical pathway from complex II to complex III in this bacterium. The presence of NADH-fumarate reductase (FRD) was demonstrated in H. pylori and fumarate could reduce H2O2 production from NADH, indicating fumarate to be an endogenous......-dependent respiration was significantly stronger than NADH-dependent respiration, indicating that this is a major respiratory electron donor in H. pylori. Fumarate and malonate exhibited a concentration-dependent inhibitory effect on the activity of succinate dehydrogenase. The activity of succinate-cytochrome c...

  18. Biomineralization

    DEFF Research Database (Denmark)

    Sand, K. K.; Pedersen, C. S.; Sjöberg, S.

    2014-01-01

    a modern coccolithophorid, Emiliania huxleyi. We generated surface complexation constants for the branch components: malonate: 14.25 ± 0.17, succinate: 11.91 ± 0.06, tricarballylate: 14.86 ± 0.04, and citrate: 15.25 ± 0.04. The implication is that complex PS could hold promise for smart material...

  19. Studies on Cross-linking of succinic acid with chitosan/collagen

    Directory of Open Access Journals (Sweden)

    Tapas Mitra

    2013-01-01

    Full Text Available The present study summarizes the cross-linking property of succinic acid with chitosan /collagen. In detail, the chemistry behind the cross-linking and the improvement in mechanical and thermal properties of the cross-linked material were discussed with suitable instruments and bioinformatics tools. The concentration of succinic acid with reference to the chosen polymers was optimized. A 3D scaffold prepared using an optimized concentration of succinic acid (0.2% (w/v with chitosan (1.0% (w/v and similarly with collagen (0.5% (w/v, was subjected to surface morphology, FT-IR analysis, tensile strength assessment, thermal stability and biocompatibility. Results revealed, cross-linking with succinic acid impart appreciable mechanical strength to the scaffold material. In silico analysis suggested the prevalence of non-covalent interactions, which played a crucial role in improving the mechanical and thermal properties of the cross-linked scaffold. The resultant 3D scaffold may find application as wound dressing material, as an implant in clinical applications and as a tissue engineering material.

  20. Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Corwin H.; Kazhdan, Daniel; Werkema, Evan L.; Walter, Marc D.; Lukens, Wayne W.; Bauer, Eric D.; Hu, Yung-Jin; Maron, Laurent; Eisenstein, Odile; Head-Gordon, Martin; Andersen, Richard A.

    2011-01-25

    Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers.

  1. Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

    2015-01-01

    The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

  2. Vitamin E Succinate as an Adjuvant for Dendritic Cell Based Vaccines

    National Research Council Canada - National Science Library

    Ramanathapuram, Lalitha V

    2006-01-01

    .... Vitamin E succinate or alpha tocopheryl succinate ( -TOS) is a non-toxic, esterified analogue of Vitamin E that has been shown to be selectively toxic to tumor cell lines in vitro as well as inhibit the growth of tumors in animal models in vivo...

  3. Vitamin E Succinate as an Adjuvant for Dendritic Cell-Based Vaccines

    National Research Council Canada - National Science Library

    Ramanathapuram, Lalitha V; Akporiaye, Emmanuel T

    2005-01-01

    .... Vitamin E succinate or alpha tocopheryl succinate (a-TOS) is a non-toxic, esterified analogue of Vitamin E that has been shown to be selectively toxic to tumor cell lines in vitro as well as inhibit the growth of tumors in animal models in vivo...

  4. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    International Nuclear Information System (INIS)

    Gurzynski, Lukasz; Puszko, Aniela; Chmurzynski, Lech

    2007-01-01

    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pK a values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase

  5. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General and Inorganic Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Chmurzynski, Lech [Department of General and Inorganic Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)], E-mail: lech@chemik.chem.univ.gda.pl

    2007-12-15

    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pK{sub a} values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase.

  6. Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

    Science.gov (United States)

    Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

    2015-04-01

    The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid. Copyright © 2015. Published by Elsevier Ltd.

  7. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    International Nuclear Information System (INIS)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-01-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO_2 and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO_2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  8. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

    2016-11-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  9. Compatibility of ondansetron hydrochloride and methylprednisolone sodium succinate in multilayer polyolefin containers.

    Science.gov (United States)

    Bougouin, Christelle; Thelcide, Chloë; Crespin-Maillard, Fabienne; Maillard, Christian; Kinowski, Jean Marie; Favier, Mireille

    2005-10-01

    The compatibility of ondansetron hydrochloride and methylprednisolone sodium succinate in 5% dextrose injection and 0.9% sodium chloride injection was studied. Test solutions of ondansetron hydrochloride 0.16 mg/mL and methylprednisolone sodium succinate 2.4 mg/mL were prepared in triplicate and tested in duplicate. Total volumes of 4 and 2 mL of ondansetron hydrochloride solution and methylprednisolone sodium succinate solution, respectively, were added to 50-mL multilayer polyolefin bags containing 5% dextrose injection or 0.9% sodium chloride injection. Bags were stored for 24 hours at 20-25 degrees C and for 48 hours at 4-8 degrees C. Chemical compatibility was measured with high-performance liquid chromatography, and physical compatibility was determined visually. Ondansetron hydrochloride was stable for up to 24 hours at 20-25 degrees C and up to 48 hours at 4-8 degrees C. Methylprednisolone sodium succinate was stable for up to 48 hours at 4-8 degrees C. When stored at 20-25 degrees C, methylprednisolone sodium succinate was stable for up to 7 hours in 5% dextrose injection and up to 24 hours in 0.9% sodium chloride injection. Compatibility data for solutions containing ondansetron hydrochloride plus methylprednisolone sodium succinate revealed that each drug was stable for up to 24 hours at 20-25 degrees C and up to 48 hours at 4-8 degrees C. Ondansetron 0.16 mg/mL (as the hydrochloride) and methylprednisolone 2.4 mg/mL (as the sodium succinate) mixed in 50-mL multilayer polyolefin bags were stable in both 5% dextrose injection and 0.9% sodium chloride injection for up to 24 hours at 20-25 degrees C and up to 48 hours at 4-8 degrees C.

  10. SMALL SCALE PREPARATION OF C14 LABELED SUCCINIC, MALIC, FUMARICAND TARTARIC ACIDS

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, E.C.; Bassham, J.A.; Calvin, M.; Tolbert, B.M.

    1951-06-12

    The directions for preparing the following acids from labeled acetic acid on a 1 to 20 millimole scale is presented: Succinic acid, malic acid, fumaric acid and tartaric acid. Two methods for preparing the succinic acid are detailed.

  11. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters.

    Science.gov (United States)

    Xie, Wen-Jie; Zhou, Xiao-Ming

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by (1)H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t1/2, Zc and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Synthesis and Crystal Structures of Two Metal Complexes Incorporating Malonate and Organodiamine Ligands

    International Nuclear Information System (INIS)

    Zhang, Quan Zheng; Yang, Wen Bin; Chen, Shu Mei; Lu, Can Zhong

    2005-01-01

    In the present work we report the synthesis and X-ray crystal structures of two new malonato complexes incorporating organodiamine ligands: [Ni(phen)(mal)(H_2O)_2]·3H_2O (H_2mal = malonic acid, phen = 1,10-phenanthroline) and [Zn(bpy)(H_2O)]_2[Zn(bpy)(mal)(H_2O)_2]_2(NO_3)_4·4H_2O (bpy = 2,2'-bipyridine). Investigation on novel organic-inorganic hybrid framework assemblies represents one of the most active areas of material science and chemical research. Major advances have been made in these materials due to their interesting properties and potential in various applications, e. g., electrical conductivity, magnetism, host-guest chemistry, ion exchange, catalysis, nonlinear optics, etc. Moreover, discovery and design of such new materials with specific networks remain of a particularly important and active subject in the field of supramolecuar chemistry and crystal engineering. A variety of complexes with interesting compositions and topologies have been prepared through taking certain factors into account, such as the coordination nature of the metal ion and the shape, functionality, flexibility, and symmetry of organic ligand. Recently, some dicarboxylate ligands, such as oxalate, malonate, and terephthalate, have been widely used in the construction of these interesting structures

  13. Genetics Home Reference: succinic semialdehyde dehydrogenase deficiency

    Science.gov (United States)

    ... Additional NIH Resources (1 link) National Institute of Neurological Disorders and Stroke: Epilepsy Information Page Educational Resources (5 links) Boston Children's Hospital: Seizures and Epilepsy Disease InfoSearch: Succinic semialdehyde ...

  14. Synthesis of carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinolinium derivatives as new potential PET SKCa channel imaging agents.

    Science.gov (United States)

    Gao, Mingzhang; Wang, Min; Zheng, Qi-Huang

    2008-02-01

    Small conductance Ca2+-activated K+ (SKCa) channels play an important role in many functions such as neuronal communication and behavioral plasticity, secretion, and cell proliferation. SKCa channel modulation is associated with various brain, heart, and cancer diseases. N-methyl-laudanosine and its structurally related derivatives, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums, are reversible and selective SKCa channel blockers. Carbon-11 labeled N-methyl-laudanosine and its tetrahydroisoquinolinium derivatives may serve as new probes for positron emission tomography (PET) to image SKCa channels in the brain, heart, and cancer. The key intermediates, substituted isoquinolines (3a-c), were synthesized using a modification of the Pomeranz-Fritsch procedure. The precursors, substituted 1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolines (8a-c), and their corresponding reference standards, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums (9a-c), were synthesized from compounds 3a-c with 3,4-dimethoxybenzyl chloride (2) in multiple steps with moderate to excellent chemical yields. The precursor 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline (10) was commercially available, and the methylation of compound 10 with methyl iodide provided N-methyl-laudanosine (11). The target quaternary ammonium tracers, carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums ([11C]9a-c and [11C]11), were prepared by N-[11C]methylation of the tertiary amine precursors (8a-c and 10) with [11C]methyl triflate and isolated by a simplified solid-phase extraction (SPE) purification using a SiO2 or cation-exchange CM Sep-Pak cartridge in 40-65% radiochemical yields.

  15. Production of succinic acid from oil palm empty fruit bunch cellulose using Actinobacillus succinogenes

    Science.gov (United States)

    Pasma, Satriani Aga; Daik, Rusli; Maskat, Mohamad Yusof

    2013-11-01

    Succinic acid is a common metabolite in plants, animals and microorganisms. It has been used widely in agricultural, food and pharmaceutical industries. Enzymatic hydrolysate glucose from oil palm empty fruit bunch (OPEFB) cellulose was used as a substrate for succinic acid production using Actinobacillus succinogenes. Using cellulose extraction from OPEFB can enhance the production of glucose as a main substrate for succinic acid production. The highest concentration of glucose produced from enzymatic hydrolysis is 167 mg/mL and the sugar recovery is 0.73 g/g of OPEFB. By optimizing the culture medium for succinic acid fermentation with enzymatic hydrolysate of OPEFB cellulose, the nitrogen sources could be reduced to just only 2.5 g yeast extract and 2.5 g corn step liquor. Batch fermentation was carried out using enzymatic hydrolysate of OPEFB cellulose with yeast extract, corn steep liquor and the salts mixture, 23.5 g/L succinic acid was obtained with consumption of 72 g/L glucose in enzymatic hydrolysate of OPEFB cellulose at 38 hours and 37°C. This study suggests that enzymatic hydrolysate of OPEFB cellulose maybe an alternative substrate for the efficient production of succinic acid by Actinobacillus succinogenes.

  16. Succinic Acid as a Byproduct in a Corn-based Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    MBI International

    2007-12-31

    MBI endeavored to develop a process for succinic acid production suitable for integration into a corn-based ethanol biorefinery. The project investigated the fermentative production of succinic acid using byproducts of corn mill operations. The fermentation process was attuned to include raw starch, endosperm, as the sugar source. A clean-not-sterile process was established to treat the endosperm and release the monomeric sugars. We developed the fermentation process to utilize a byproduct of corn ethanol fermentations, thin stillage, as the source of complex nitrogen and vitamin components needed to support succinic acid production in A. succinogenes. Further supplementations were eliminated without lowering titers and yields and a productivity above 0.6 g l-1 hr-1was achieved. Strain development was accomplished through generation of a recombinant strain that increased yields of succinic acid production. Isolation of additional strains with improved features was also pursued and frozen stocks were prepared from enriched, characterized cultures. Two recovery processes were evaluated at pilot scale and data obtained was incorporated into our economic analyses.

  17. Mutant E. coli strain with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2001-09-25

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  18. Mutant E. coli strain with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    1998-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  19. (E-2-((4R,5R-5-((Benzyloxymethyl-2,2-dimethyl-1,3-dioxolan-4-ylbut-2-ene-1,4-diol

    Directory of Open Access Journals (Sweden)

    Carlos R. Carreras

    2010-04-01

    Full Text Available The synthesis of (E-2-((4R,5R-5-((benzyloxymethyl-2,2-dimethyl-1,3-dioxolan-4-ylbut-2-ene-1,4-diol by a one-step reduction of the appropriate 2-substituted butenolide is reported. Product characterization was carried out by IR, 1H NMR, 13C NMR, MS, elemental analysis and optical rotation.

  20. The succinate receptor as a novel therapeutic target for oxidative and metabolic stress-related conditions.

    Directory of Open Access Journals (Sweden)

    Ana Carolina eAriza

    2012-02-01

    Full Text Available The succinate receptor (also known as GPR91 is a G protein-coupled receptor that is closely related to the family of P2Y purinoreceptors. It is expressed in a variety of tissues, including blood cells, adipose tissue, the liver, retina and kidney. In these tissues, this receptor and its ligand succinate have recently emerged as novel mediators in local stress situations, including ischemia, hypoxia, toxicity and hyperglycemia. Amongst others, the succinate receptor is involved in recruitment of immune cells to transplanted tissues. Moreover, it was shown to play a key role in the development of diabetic retinopathy. However, most prominently, the role of locally increased succinate levels and succinate receptor activation in the kidney, stimulating the systemic and local renin-angiotensin system, starts to unfold: The succinate receptor is a key mediator in the development of hypertension and possibly fibrosis in diabetes mellitus and metabolic syndrome. This makes the succinate receptor a promising drug target to counteract or prevent cardiovascular and fibrotic defects in these expanding disorders. Recent development of SUCNR1-specific antagonists opens novel possibilities for research in models for these disorders and may eventually provide novel opportunities for the treatment of patients.

  1. Facile Syntheses and Molecular-Docking of Novel Substituted 3,4-Dimethyl-1H-pyrrole-2-carboxamide/carbohydrazide Analogues with Antimicrobial and Antifungal Properties

    Directory of Open Access Journals (Sweden)

    Jitendra D. Bhosale

    2018-04-01

    Full Text Available The article describes the use of facile one-pot, high-yielding reactions to synthesize substituted 3,4-dimethyl-1H-pyrrole-2-carboxamides 3a–m and carbohydrazide analogues 5a–l as potential antifungal and antimicrobial agents. The structural identity and purity of the synthesized compounds were assigned based on appropriate spectroscopic techniques. Synthesized compounds were assessed in vitro for antifungal and antibacterial activity. The compounds 5h, 5i and 5j were found to be the most potent against Aspergillus fumigatus, with MIC values of 0.039 mg/mL. The compound 5f bearing a 2, 6-dichloro group on the phenyl ring was found to be the most active broad spectrum antibacterial agent with a MIC value of 0.039 mg/mL. The mode of action of the most promising antifungal compounds (one representative from each series; 3j and 5h was established by their molecular docking with the active site of sterol 14α-demethylase. Molecular docking studies revealed a highly spontaneous binding ability of the tested compounds in the access channel away from catalytic heme iron of the enzyme, which suggested that the tested compounds inhibit this enzyme and would avoid heme iron-related deleterious side effects observed with many existing antifungal compounds.

  2. Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

    Directory of Open Access Journals (Sweden)

    Antczak Jerzy

    2014-06-01

    Full Text Available This paper applies the determined suitability of nanofiltration (NF membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

  3. Interaction of Palmitic Acid with Metoprolol Succinate at the Binding Sites of Bovine Serum Albumin

    Directory of Open Access Journals (Sweden)

    Mashiur Rahman

    2014-12-01

    Full Text Available Purpose: The aim of this study was to characterize the binding profile as well as to notify the interaction of palmitic acid with metoprolol succinate at its binding site on albumin. Methods: The binding of metoprolol succinate to bovine serum albumin (BSA was studied by equilibrium dialysis method (ED at 27°C and pH 7.4, in order to have an insight in the binding chemistry of the drug to BSA in presence and absence of palmitic acid. The study was carried out using ranitidine as site-1 and diazepam as site-2 specific probe. Results: Different analysis of binding of metoprolol succinate to bovine serum albumin suggested two sets of association constants: high affinity association constant (k1 = 11.0 x 105 M-1 with low capacity (n1 = 2 and low affinity association (k2 = 4.0×105 M-1 constant with high capacity (n2 = 8 at pH 7.4 and 27°C. During concurrent administration of palmitic acid and metoprolol succinate in presence or absence of ranitidine or diazepam, it was found that palmitic acid displaced metoprolol succinate from its binding site on BSA resulting reduced binding of metoprolol succinate to BSA. The increment in free fraction of metoprolol succinate was from 26.27% to 55.08% upon the addition of increased concentration of palmitic acid at a concentration of 0×10-5 M to 16×10-5 M. In presence of ranitidine and diazepam, palmitic acid further increases the free fraction of metoprolol succinate from 33.05% to 66.95% and 40.68% to 72.88%, respectively. Conclusion: This data provided the evidence of interaction at higher concentration of palmitic acid at the binding sites on BSA, which might change the pharmacokinetic properties of metoprolol succinate.

  4. Krebs cycle metabolite profiling for identification and stratification of pheochromocytomas/paragangliomas due to succinate dehydrogenase deficiency.

    Science.gov (United States)

    Richter, Susan; Peitzsch, Mirko; Rapizzi, Elena; Lenders, Jacques W; Qin, Nan; de Cubas, Aguirre A; Schiavi, Francesca; Rao, Jyotsna U; Beuschlein, Felix; Quinkler, Marcus; Timmers, Henri J; Opocher, Giuseppe; Mannelli, Massimo; Pacak, Karel; Robledo, Mercedes; Eisenhofer, Graeme

    2014-10-01

    Mutations of succinate dehydrogenase A/B/C/D genes (SDHx) increase susceptibility to development of pheochromocytomas and paragangliomas (PPGLs), with particularly high rates of malignancy associated with SDHB mutations. We assessed whether altered succinate dehydrogenase product-precursor relationships, manifested by differences in tumor ratios of succinate to fumarate or other metabolites, might aid in identifying and stratifying patients with SDHx mutations. PPGL tumor specimens from 233 patients, including 45 with SDHx mutations, were provided from eight tertiary referral centers for mass spectrometric analyses of Krebs cycle metabolites. Diagnostic performance of the succinate:fumarate ratio for identification of pathogenic SDHx mutations. SDH-deficient PPGLs were characterized by 25-fold higher succinate and 80% lower fumarate, cis-aconitate, and isocitrate tissue levels than PPGLs without SDHx mutations. Receiver-operating characteristic curves for use of ratios of succinate to fumarate or to cis-aconitate and isocitrate to identify SDHx mutations indicated areas under curves of 0.94 to 0.96; an optimal cut-off of 97.7 for the succinate:fumarate ratio provided a diagnostic sensitivity of 93% at a specificity of 97% to identify SDHX-mutated PPGLs. Succinate:fumarate ratios were higher in both SDHB-mutated and metastatic tumors than in those due to SDHD/C mutations or without metastases. Mass spectrometric-based measurements of ratios of succinate:fumarate and other metabolites in PPGLs offer a useful method to identify patients for testing of SDHx mutations, with additional utility to quantitatively assess functionality of mutations and metabolic factors responsible for malignant risk.

  5. Organometallic complexes of thiocarbanilides and substituted thiocarbanilides using manganese (II) chloride

    International Nuclear Information System (INIS)

    Babiker, Musa Elaballa Mohamed

    2000-01-01

    Organo-metallic complexes of substituted thiocarbanilide using manganese (II) chloride were prepared, these are: (VIII) 3:3'-Dichloro thiocarbanilide. Manganese (II) chloride. (IX) 3:3'-Dimethyl thiocarbanilide. Manganese (II) chloride. (X) 2:2'-dimethyl thiocarbanilide. Manganese (II) chloride. These compounds are coloured, soluble in most organic solvents, insoluble in water, decomposed by hot solvents. The physical properties of compounds (IX) and (X) were studied by UV and IR spectra, and the physical properties of compound (VIII) were studied by UV, IR, mass spectra and NMR. The molecular weight of the compound (VIII) was determined by three different methods; Rast's camphor method, mass spectra and the nitrogen contents. The stoichiometry of the reaction was found to be 2:1, and the coordination is from sulphur atom more than nitrogen.(Author)

  6. Malonate-based inhibitors of mammalian serine racemase: Kinetic characterization and structure-based computational study

    Czech Academy of Sciences Publication Activity Database

    Vorlová, Barbora; Nachtigallová, Dana; Jirásková-Vaníčková, Jana; Ajani, Haresh; Jansa, Petr; Řezáč, Jan; Fanfrlík, Jindřich; Otyepka, M.; Hobza, Pavel; Konvalinka, Jan; Lepšík, Martin

    2015-01-01

    Roč. 89, Jan 7 (2015), s. 189-197 ISSN 0223-5234 R&D Projects: GA ČR GBP208/12/G016 Grant - others:GA MŠk(CZ) ED2.1.00/03.0058 Program:ED Institutional support: RVO:61388963 Keywords : NMDA receptor * pyridoxal-5 '-phosphate-dependent enzyme * human/mouse serine racemase * malonate-based inhibitors * semiempirical quantum mechanical calculations Subject RIV: CE - Biochemistry Impact factor: 3.902, year: 2015

  7. Ethyl malonate amides: a diketo acid offspring fragment for HIV integrase inhibition.

    Science.gov (United States)

    Serafin, Katarzyna; Mazur, Pawel; Bak, Andrzej; Laine, Elodie; Tchertanov, Luba; Mouscadet, Jean-François; Polanski, Jaroslaw

    2011-08-15

    While searching for new HIV integrase inhibitors we discovered that some ethyl malonate amides (EMA) are active against this enzyme. Surprisingly, the main function can only very rarely be found among the reported drug candidates. We synthesised a series of compounds in order to establish and analyse the structure-activity relationship. The similarity to the important classes of HIV integrase inhibitors as well as the synthetic availability of the different targets including this pharmacophore makes EMA compounds an interesting object of investigations. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Synthesis of carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinolinium derivatives as new potential PET SK{sub Ca} channel imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Gao Mingzhang; Wang Min [Department of Radiology, Indiana University School of Medicine, 1345 West 16th Street, L-3 Room 202, Indianapolis, IN 46202 (United States); Zheng Qihuang [Department of Radiology, Indiana University School of Medicine, 1345 West 16th Street, L-3 Room 202, Indianapolis, IN 46202 (United States)], E-mail: qzheng@iupui.edu

    2008-02-15

    Small conductance Ca{sup 2+}-activated K{sup +} (SK{sub Ca}) channels play an important role in many functions such as neuronal communication and behavioral plasticity, secretion, and cell proliferation. SK{sub Ca} channel modulation is associated with various brain, heart, and cancer diseases. N-methyl-laudanosine and its structurally related derivatives, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums, are reversible and selective SK{sub Ca} channel blockers. Carbon-11 labeled N-methyl-laudanosine and its tetrahydroisoquinolinium derivatives may serve as new probes for positron emission tomography (PET) to image SK{sub Ca} channels in the brain, heart, and cancer. The key intermediates, substituted isoquinolines (3a-c), were synthesized using a modification of the Pomeranz-Fritsch procedure. The precursors, substituted 1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolines (8a-c), and their corresponding reference standards, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums (9a-c), were synthesized from compounds 3a-c with 3,4-dimethoxybenzyl chloride (2) in multiple steps with moderate to excellent chemical yields. The precursor 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3, 4-tetrahydroisoquinoline (10) was commercially available, and the methylation of compound 10 with methyl iodide provided N-methyl-laudanosine (11). The target quaternary ammonium tracers, carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums ([{sup 11}C]9a-c and [{sup 11}C]11), were prepared by N-[{sup 11}C]methylation of the tertiary amine precursors (8a-c and 10) with [{sup 11}C]methyl triflate and isolated by a simplified solid-phase extraction (SPE) purification using a SiO{sub 2} or cation-exchange CM Sep-Pak cartridge in 40-65% radiochemical yields.

  9. The Analysis of Silver Nanoparticles After the Manipulation of Synthesis Parameters and with the Addition of Potassium 2-(9-Carboxy-1-Octylnonylsulfanyl)-Malonate

    International Nuclear Information System (INIS)

    Chin, S.Y.; Hakam, M.A.O.; Goh, S.C.; Yarmo, M.A.

    2011-01-01

    This research aimed to synthesize and characterize silver nanoparticles by manipulating the parameters involved in stabilizing the particles. The silver nanoparticles in this research were synthesized by reduction process of silver nitrate (AgNO 3 ) with sodium borohydrate (NaBH 4 ) as the reducing agent. The addition of potassium 2- (9-carboxy-1-octylnonylsulfanyl)-malonate into silver nanoparticles solution functioned as a stabilizing agent. The parameters involved in this research were the effect of time towards stability of silver nanoparticles, the effect of addition of potassium 2-(9-carboxy-1-octylnonylsulfanyl)- malonate and the pH level effect towards the synthesized silver nanoparticles. Based on the results obtained from Transmission Electron Microscopy (TEM), we have observed that the incorporation of potassium 2-(9-carboxy-1- octyl-nonanesulfonyl)-malonate as the stabilizing agent can prevent the agglomeration of silver nanoparticles within 16 days which is a breakthrough for the synthesis of silver nanoparticles by using sodium borohydride. The micrograph showed that the size of silver nanoparticles synthesized were within the range of 1.5 nm to 8.3 nm. In addition to that, Dynamic Light Scattering (DLS) technique was used in this research to measure the average size of the silver nanoparticles which stabilized with potassium 2-(9-carboxy-1-octyl-nonanesulfonyl)-malonate. X-Ray Diffraction (XRD) analysis was carried out to view the effect of manipulated pH level on crystalline silver nanoparticles structure. The XRD diffractogram showed the diffraction peaks which can be indexed to planes of face- centered cubic (fcc) of pure silver. (author)

  10. Biophysical properties of phenyl succinic acid derivatised hyaluronic acid

    DEFF Research Database (Denmark)

    Neves-Petersen, Maria Teresa; Klitgaard, Søren; Skovsen, Esben

    2010-01-01

    Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic...... acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored...

  11. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Science.gov (United States)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-11-01

    Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  12. Fourier Transform Infrared Spectroscopy Study on Cation adsorption on Viscose Rayon Succinate

    Directory of Open Access Journals (Sweden)

    D Khasbaatar

    2014-09-01

    Full Text Available Ion-exchange materials have been considered as suitable material for the recovery of heavy metals in water. A viscose rayon succinate, synthesized from viscose rayon and succinic anhydride in presence of DMSO, to remove trace bivalent metal ions such as Ag+, Cu2+, Ni2+, Pb2+, Zn2+ and Cr3+, was studied using FT-IR for the behavior of metal adsorption. Both esterification and carboxyl bonding of viscose rayon succinate were assigned essentially at 1729 and 1693cm-1, respectively. And the essential band of bonding between metal and the material was determined at 1625cm-1. The available adsorption capacity of this fiber was 6.2 mequiv/g. The adsorption of metal ions on the viscose rayon succinate follows the order of Cu2+>Cr3+>Ni2+>Pb2+>Zn2+>Ag+ with maximum adsorptions capacities 4.2, 1.42, 0.91, 0.83, 0.69 and 0.35 mmol/g, respectively.DOI: http://dx.doi.org/10.5564/mjc.v12i0.189 Mongolian Journal of Chemistry Vol.12 2011: 136-141

  13. A novel process for recovery of fermentation-derived succinic acid: process design and economic analysis.

    Science.gov (United States)

    Orjuela, Alvaro; Orjuela, Andrea; Lira, Carl T; Miller, Dennis J

    2013-07-01

    Recovery and purification of organic acids produced in fermentation constitutes a significant fraction of total production cost. In this paper, the design and economic analysis of a process to recover succinic acid (SA) via dissolution and acidification of succinate salts in ethanol, followed by reactive distillation to form succinate esters, is presented. Process simulation was performed for a range of plant capacities (13-55 million kg/yr SA) and SA fermentation titers (50-100 kg/m(3)). Economics were evaluated for a recovery system installed within an existing fermentation facility producing succinate salts at a cost of $0.66/kg SA. For a SA processing capacity of 54.9 million kg/yr and a titer of 100 kg/m(3) SA, the model predicts a capital investment of $75 million and a net processing cost of $1.85 per kg SA. Required selling price of diethyl succinate for a 30% annual return on investment is $1.57 per kg. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. SYNTHESIS AND EVALUATION OF NEW PHTHALAZINE SUBSTITUTED β-LACTAM DERIVATIVES AS CARBONIC ANHYDRASE INHIBITORS.

    Science.gov (United States)

    Berber, Nurcan; Arslan, Mustafa; Bilen, Çiğdem; Sackes, Zübeyde; Gençer, Nahit; Arslan, Oktay

    2015-01-01

    A new series of phthalazine substituted β-lactam derivatives were synthesized and their inhibitory effects on the activity of purified human carbonic anhydrase (hCA I and II) were evaluated. 2H-Indazolo[2,1-b]phthala- zine-trione derivative was prepared with 4-nitrobenzaldehyde, dimedone, and phthalhydrazide in the presence of TFA in DMF, and the nitro group was reduced to 13-(4-aminophenyl)-3,3-dimethyl-3,4-dihydro- 2H-indazolo[1,2-b]phthalazine-1,6,11(13H)-trione with SnCl2 · 2H2O. The reduced compound was re- acted with different aromatic aldehydes, and phthalazine substituted imines were synthesized. The imine compounds undergo (2+2) cycloaddition reactions with ketenes to produce 2H-indazolo[2,1-b]phthala-zine-trione substituted β-lactam derivatives. The β-lactam compounds were tested as inhibitors of the CA isoenzyme activity. The results showed that all the synthesized compounds inhibited the CA isoenzyme activity. 1-(4-(3,3-dimethyl- 1,6,1 1-trioxo-2,3,4,6,11,13-hexahydro-1H-indazolo[1,2-b]phthalazin-13- yl)phenyl)-2-oxo-4-p-tolylazetidin-3-yl acetate (IC50 = 6.97 µM for hCA I and 8.48 µM for hCA II) had the most inhibitory effect.

  15. Rheological, pasting, thermal and retrogradation properties of octenyl succinic anhydride modified potato starch

    Directory of Open Access Journals (Sweden)

    Chuin WON

    Full Text Available Abstract The objective of the present study was to investigate the rheological, pasting, and thermal properties of octenyl succinic anhydrate (OSA-modified potato starch. Potato starch was modified using different concentrations of OSA (0, 1, 3, and 5%, v/v. The degree of substitution (DS for the OSA-modified starch ranged from 0.0012 to 0.0055. The amylose leaching values of native and OSA-modified potato starch with different DS levels were in the range of 47.09-87.32%. The gel strength values of the OSA-modified starch were lower than those of native potato starch. Rapid Visco Analyzer data showed that peak, hot pasting, final and setback viscosities of the native starch decreased after OSA modification. Dynamic shear rheological tests, conducted at 4 °C, indicated that OSA-modified potato starch had weak gel-like behavior with the storage moduli (G' higher than the loss moduli (G” over most of the frequency ranges (0.63-63.8 rad·s-1.

  16. Improved sugar-free succinate production by Synechocystis sp. PCC 6803 following identification of the limiting steps in glycogen catabolism

    Directory of Open Access Journals (Sweden)

    Tomohisa Hasunuma

    2016-12-01

    Full Text Available Succinate produced by microorganisms can replace currently used petroleum-based succinate but typically requires mono- or poly-saccharides as a feedstock. The cyanobacterium Synechocystis sp. PCC6803 can produce organic acids such as succinate from CO2 not supplemented with sugars under dark anoxic conditions using an unknown metabolic pathway. The TCA cycle in cyanobacteria branches into oxidative and reductive routes. Time-course analyses of the metabolome, transcriptome and metabolic turnover described here revealed dynamic changes in the metabolism of Synechocystis sp. PCC6803 cultivated under dark anoxic conditions, allowing identification of the carbon flow and rate-limiting steps in glycogen catabolism. Glycogen biosynthesized from CO2 assimilated during periods of light exposure is catabolized to succinate via glycolysis, the anaplerotic pathway, and the reductive TCA cycle under dark anoxic conditions. Expression of the phosphoenolpyruvate (PEP carboxylase gene (ppc was identified as a rate-limiting step in succinate biosynthesis and this rate limitation was alleviated by ppc overexpression, resulting in improved succinate excretion. The sugar-free succinate production was further enhanced by the addition of bicarbonate. In vivo labeling with NaH13CO3 clearly showed carbon incorporation into succinate via the anaplerotic pathway. Bicarbonate is in equilibrium with CO2. Succinate production by Synechocystis sp. PCC6803 therefore holds significant promise for CO2 capture and utilization. Keywords: Autofermentation, Cyanobacteria, Dynamic metabolic profiling, Metabolomics, Succinate, Synechocystis

  17. Memory effects in palladium-catalyzed allylic Alkylations of 2-cyclohexen-1-yl acetate

    DEFF Research Database (Denmark)

    Svensen, Nina; Fristrup, Peter; Tanner, David Ackland

    2007-01-01

    The objective of this work was to characterize the enantiospecificity of the allylic alkylation of enantioenriched 2-cyclohexen-1-yl acetate with the enolate ion of dimethyl malonate catalyzed by unsymmetrical palladium catalysts. The precatalysts employed were (eta(3)-allyl)PdLCl, where L...

  18. Exploring 3D non-interpenetrated metal-organic framework with malonate-bridged Co(II) coordination polymer: structural elucidation and theoretical study

    Science.gov (United States)

    Hossain, Anowar; Mandal, Tripti; Mitra, Monojit; Manna, Prankrishna; Bauzá, Antonio; Frontera, Antonio; Seth, Saikat Kumar; Mukhopadhyay, Subrata

    2017-12-01

    A Co(II)-based coordination polymer with tetranuclear cobalt(II)-malonate cluster has been easily generated by aqueous medium self-assembly from Cobalt(II) chloride hexahydrate and malonic acid. The structure exhibits a non-interpenetrating, highly undulating two-dimensional (2D) bi-layer network with (4,4) topology. The crystal structure is composed of infinite interdigitated 2D metal-organic bi-layers which extended to an intricate 3D framework through the interbilayer hydrogen bonds. We have studied energetically by means of Density Functional Theory (DFT) calculations the H-bonding interactions that connect the 2D metal-organic bi-layers. The finite theoretical models have been used to compute conventional O‒H•••O and unconventional C‒H•••O interactions which plays a key role to build 3D architecture.

  19. The Malone antegrade continence enema for neurogenic and structural fecal incontinence and constipation.

    Science.gov (United States)

    Koyle, M A; Kaji, D M; Duque, M; Wild, J; Galansky, S H

    1995-08-01

    Problems of fecal elimination are commonly encountered by the pediatric urologist and surgeon. The Malone antegrade continence enema has been described as a means to administer a large volume enema via a continent catheterizable appendicocecostomy, resulting in reliable fecal elimination. Of 22 patients undergoing this procedure 16 reported total continence 4 months or longer after surgery. Complications are relatively minor and tap water appears to be a safe solution for the antegrade continence enema. A nonrefluxing, imbricated appendicocecostomy is preferable to prevent cutaneous fecal or gas leaks.

  20. Crystallographic characterization of single-ortho, N-substituted acetanilide derivatives

    International Nuclear Information System (INIS)

    Boeyens, J.C.A.; Denner, L.; Painter, S.; Staskun, B.

    1987-01-01

    The crystal and molecular structures of the three single-ortho, N-substituted amide derivatives, acet-2'-bromo-N-(p-nitrobenzyl)anilide, 3',5'-dimethyl-N-ethyl-2,2,2',4'-tetrachlorobenzoylacetanilide, and difluoro[(1-phenyl-2-(o-ethylphenyl-N-benzylcarbamoyl)vinyl)oxy]borane, have been determined by X-ray diffraction analysis. In each case, the amide carbonyl group was found in the exo-conformation, independent of the nature of the acyl group. The observed conformations correlate well with solution structures, inferred from n.m.r. data

  1. Structural and magnetic studies on copper succinate dihydrate ...

    Indian Academy of Sciences (India)

    M P BINITHA

    2017-08-21

    Aug 21, 2017 ... rials chemistry, heterogeneous catalysis, gas storage, polymer magnets, etc. ... super exchange interactions among copper atoms through bridging .... Thus, these two water molecules in the structure of copper succinate are.

  2. Synthesis and characterization of new 2-amino-4-(substituted phenyl-6-(7’’-methoxy, 3’’,4’’-dihydro, 2’’,2’’-dimethyl-2hbenzopyran pyrimidines and their bio evaluation

    Directory of Open Access Journals (Sweden)

    Murthy Y.L.N.

    2012-01-01

    Full Text Available A series of eight novel 2-amino-4-(substituted phenyl-6-(7"- methoxy, 3",4"-dihydro, 2",2"-dimethyl-2H-benzopyran pyrimidines were designed and synthesized by utilizing benzene-1,3-diol as starting material. The structures of the isolated products (6a-h were established through 1HNMR, 13C-NMR, and FT-IR spectroscopic techniques and elemental analysis. The synthesized compounds were utilized for screening antimicrobial properties against gram positive (Bacillus pumilus, Bacillus subtilis, Streptococcus faecalis, gram negative bacteria (Enterococcus faecalis, Escheria coli, Proteus vulgaris and fungi (Pencillian expasom, Aspergillus niger, Candida albicans using Ampicillin and Ketoconazole. Most of the compounds showed moderate to high antibacterial and antifungal activities against studied strains with inhibition zones between 8 and 30 mm.

  3. 78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

    Science.gov (United States)

    2013-12-18

    ..., Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs.; Tolerance Exemption... an exemption from the requirement of a tolerance for residues of tall oil, polymer with polyethylene..., polymer with polyethylene glycol and succinic anhydride monopolyisobutylene derivs. on food or feed...

  4. Genetic manipulation of a metabolic enzyme and a transcriptional regulator increasing succinate excretion from unicellular cyanobacterium

    Directory of Open Access Journals (Sweden)

    Takashi eOsanai

    2015-10-01

    Full Text Available Succinate is a building block compound that the U.S. Department of Energy has declared as important in biorefineries, and it is widely used as a commodity chemical. Here, we identified the two genes increasing succinate production of the unicellular cyanobacterium Synechocystis sp. PCC 6803. Succinate was excreted under dark, anaerobic conditions, and its production level increased by knocking out ackA, which encodes an acetate kinase, and by overexpressing sigE, which encodes an RNA polymerase sigma factor. Glycogen catabolism and organic acid biosynthesis were enhanced in the mutant lacking ackA and overexpressing sigE, leading to an increase in succinate production reaching 5 times of the wild-type levels. Our genetic and metabolomic analyses thus demonstrated the effect of genetic manipulation of a metabolic enzyme and a transcriptional regulator on succinate excretion from this cyanobacterium with the data based on metabolomic technique.

  5. Genotoxicity of meso-2,3-dimercapto succinic acid-coated silver sulfide quantum dot

    Directory of Open Access Journals (Sweden)

    Deniz Özkan Vardar

    2015-06-01

    Full Text Available Nanotecnology products have been used in wide applications in chemistry, electronics, energy generation, and medicine. Despite significant interest in developing quantum dots (QDs for biomedical applications, many researchers are convinced that QDs will never be used for the treatment of patients because of their potential toxicity. In various in vitro cell culture studies, the cytotoxic properties of some QD have been demonstrated and they have been suggested to be toxic in humans. In this study, the cytotoxic properties of Ag2S-(Meso-2,3-Dimercapto Succinic acid nanomaterials in V79 cells (Chinese lung fibroblast cell line were determined by MTT assay. The genotoxic effects of Ag2S-(Meso-2,3-Dimercapto Succinic acid were evaluated by the alkaline single cell gel electrophoresis. The cells were treated with Ag2S-(Meso-2,3-Dimercapto Succinic acid at the concentrations of 5- 2000 µg/ml. No cytotoxic effect of Ag2S-(Meso-2,3-Dimercapto Succinic acid at all concentrations studied was observed. No significant increases in DNA damage were found at the studied concentrations when compared to negative control in V79 cells. In conclusion, further in vitro and in vivo studies are required to determine the safety doses of Ag2S-(Meso-2,3-Dimercapto Succinic acid.

  6. Succinic acid production from orange peel and wheat straw by batch fermentations of Fibrobacter succinogenes S85.

    Science.gov (United States)

    Li, Qiang; Siles, Jose A; Thompson, Ian P

    2010-10-01

    Succinic acid is a platform molecule that has recently generated considerable interests. Production of succinate from waste orange peel and wheat straw by consolidated bioprocessing that combines cellulose hydrolysis and sugar fermentation, using a cellulolytic bacterium, Fibrobacter succinogenes S85, was studied. Orange peel contains D-limonene, which is a well-known antibacterial agent. Its effects on batch cultures of F. succinogenes S85 were examined. The minimal concentrations of limonene found to inhibit succinate and acetate generation and bacterial growth were 0.01%, 0.1%, and 0.06% (v/v), respectively. Both pre-treated orange peel by steam distillation to remove D: -limonene and intact wheat straw were used as feedstocks. Increasing the substrate concentrations of both feedstocks, from 5 to 60 g/L, elevated succinate concentration and productivity but lowered the yield. In addition, pre-treated orange peel generated greater succinate productivities than wheat straw but had similar resultant titres. The greatest succinate titres were 1.9 and 2.0 g/L for pre-treated orange peel and wheat straw, respectively. This work demonstrated that agricultural waste such as wheat straw and orange peel can be biotransformed to succinic acid by a one-step consolidated bioprocessing. Measures to increase fermentation efficiency are also discussed.

  7. Receptor structure-based discovery of non-metabolite agonists for the succinate receptor GPR91

    DEFF Research Database (Denmark)

    Trauelsen, Mette; Rexen Ulven, Elisabeth; Hjorth, Siv A

    2017-01-01

    OBJECTIVE: Besides functioning as an intracellular metabolite, succinate acts as a stress-induced extracellular signal through activation of GPR91 (SUCNR1) for which we lack suitable pharmacological tools. METHODS AND RESULTS: Here we first determined that the cis conformation of the succinate...

  8. Succinic acid production by Actinobacillus succinogenes using hydrolysates of spent yeast cells and corn fiber.

    Science.gov (United States)

    Chen, Ke-Quan; Li, Jian; Ma, Jiang-Feng; Jiang, Min; Wei, Ping; Liu, Zhong-Min; Ying, Han-Jie

    2011-01-01

    The enzymatic hydrolysate of spent yeast cells was evaluated as a nitrogen source for succinic acid production by Actinobacillus succinogenes NJ113, using corn fiber hydrolysate as a carbon source. When spent yeast cell hydrolysate was used directly as a nitrogen source, a maximum succinic acid concentration of 35.5 g/l was obtained from a glucose concentration of 50 g/l, with a glucose utilization of 95.2%. Supplementation with individual vitamins showed that biotin was the most likely factor to be limiting for succinic acid production with spent yeast cell hydrolysate. After supplementing spent yeast cell hydrolysate and 90 g/l of glucose with 150 μg/l of biotin, cell growth increased 32.5%, glucose utilization increased 37.6%, and succinic acid concentration was enhanced 49.0%. As a result, when biotin-supplemented spent yeast cell hydrolysate was used with corn fiber hydrolysate, a succinic acid yield of 67.7% was obtained from 70.3 g/l of total sugar concentration, with a productivity of 0.63 g/(l h). Our results suggest that biotin-supplemented spent yeast cell hydrolysate may be an alternative nitrogen source for the efficient production of succinic acid by A. succinogenes NJ113, using renewable resources. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  9. A novel organic nonlinear optical crystal: Creatininium succinate

    Energy Technology Data Exchange (ETDEWEB)

    Thirumurugan, R.; Anitha, K., E-mail: singlecerystalxrd@gmail.ciom [School of Physics, Madurai Kamraj University, Madurai 625021 (India)

    2015-06-24

    A novel organic material complex of creatininium succinate (CS) has been synthesized and single crystals were grown by the reaction of creatinine and succinic acid from aqueous solution by employing the technique of slow evaporation at room temperature. The structure of the grown crystal has been elucidated using single crystal X-ray diffraction analysis and the structure was refined by least-squares method to R = 0.027 for 1840 reflections. FT-IR spectral investigation has been carried out to identify the various functional groups in the title compound. UV–Vis transmission was carried out which shows the crystal has a good optical transmittance in the visible region with lower cutoff wavelength around 220 nm. Nonlinear optical property of the crystal was confirmed by Kurtz-Perry powder technique.

  10. Molecular and Supramolecular Changes in Polybutylene Succinate (PBS and Polybutylene Succinate Adipate (PBSA Copolymer during Degradation in Various Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Michał Puchalski

    2018-03-01

    Full Text Available In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS and polybutylene succinate adipate (PBSA copolymer during degradation is described. The experiment was carried out by the use of injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by size-exclusion chromatography (SEC coupled with multiangle laser light scattering (MALLS detection and wide-angle X-ray diffraction (WAXD. Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impacts of the selected degradation conditions on the macroscopic, supramolecular and molecular parameters of the studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

  11. Novel one-pot synthesis of dicarboxylic acids mediated alginate-zirconium biopolymeric complex for defluoridation of water.

    Science.gov (United States)

    Prabhu, Subbaiah Muthu; Meenakshi, Sankaran

    2015-04-20

    The present investigation explains the fluoride removal from aqueous solution using alginate-zirconium complex prepared with respective dicarboxylic acids like oxalic acid (Ox), malonic acid (MA) and succinic acid (SA) as a medium. The complexes viz., alginate-oxalic acid-zirconium (Alg-Ox-Zr), alginate-malonic acid-zirconium (Alg-MA-Zr) and alginate-succinic acid-zirconium (Alg-SA-Zr) were synthesized and studied for fluoride removal. The synthesized complexes were characterized by FTIR, XRD, SEM with EDAX and mapping images. The effects of various operating parameters were optimized. The result showed that the maximum removal of fluoride 9653mgF(-)/kg was achieved by Alg-Ox-Zr complex at acidic pH in an ambient atmospheric condition. Equilibrium data of Alg-Ox-Zr complex was fitted well with Freundlich isotherm. The calculated values of thermodynamic parameters indicated that the fluoride adsorption is spontaneous and endothermic in nature. The mechanism of fluoride removal behind Alg-Ox-Zr complex has been proposed in detail. The suitability of the Alg-Ox-Zr complex has been tested with the field sample collected in a nearby fluoride endemic area. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Preparation and structural characterisation of novel and versatile amphiphilic octenyl succinic anhydride-modified hyaluronic acid derivatives

    DEFF Research Database (Denmark)

    Eenschooten, Corinne Diane; Guillaumie, Fanny; Kontogeorgis, Georgios

    2010-01-01

    and structurally characterised by Fourier transform-infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H NMR). The influence of four reaction parameters on the DS of the derivatives was studied by means of an experimental design. The results showed that the OSA/HA molar ratio, the buffer......The purpose of the present study was to prepare amphiphilic hyaluronic acid (HA) derivatives and to study the influence of a selection of reaction parameters on the degree of substitution (DS) of the derivatives. Octenyl succinic anhydride (OSA)–modified HA (OSA–HA) derivatives were prepared...... (NaHCO3) concentration and their interaction had the largest influence while the HA concentration and the reaction time only had a negligible effect. According to 1H NMR the maximum DS achieved within the experimental conditions tested was 43% per disaccharide unit. Moreover optimal reaction...

  13. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters

    International Nuclear Information System (INIS)

    Xie, Wen-Jie; Zhou, Xiao-Ming

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by 1 H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t 1/2 , Z c and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. - Highlights: • The incorporation of NPGS units reduced the spherulite size of BS unit. • The existence of NPGS units did not change the crystal structure of BS unit. • The NPGS units incorporated in PBS could significantly improve the ductility of PBS. • The

  14. Cryosurgical treatment of warts: dimethyl ether and propane versus liquid nitrogen - case report and review of the literature.

    Science.gov (United States)

    Nguyen, Nicholas V; Burkhart, Craig G

    2011-10-01

    For years, dermatologists have relied on cryotherapy with liquid nitrogen as a safe and effective treatment for warts. More recently, several over-the-counter (OTC) wart-freezing therapies have become available. Manufacturers have substituted liquid nitrogen with dimethyl ether and propane (DMEP), and marketed these new preparations to be safe and effective alternatives to in-office cryotherapy with liquid nitrogen. However, data from in vitro studies and comparative studies in humans refute manufacturers' claims that these products reproduce in-office cryotherapy.

  15. Enantioselective γ-Alkylation of α,β-Unsaturated Malonates and Ketoesters by a Sequential Ir-Catalyzed Asymmetric Allylic Alkylation/Cope Rearrangement

    OpenAIRE

    Liu, Wen-Bo; Okamoto, Noriko; Alexy, Eric J.; Hong, Allen Y.; Tran, Kristy; Stoltz, Brian M.

    2016-01-01

    A catalytic, enantioselective ? -alkylation of ?,?-unsaturated malonates and ketoesters is reported. This strategy entails a highly regio- and enantioselective iridium-catalyzed ?-alkylation of an extended enolate, and a subsequent translocation of chirality to the ?-position via a Cope rearrangement.

  16. Inactivation of MXR1 Abolishes Formation of Dimethyl Sulfide from Dimethyl Sulfoxide in Saccharomyces cerevisiae

    OpenAIRE

    Hansen, Jørgen

    1999-01-01

    Dimethyl sulfide (DMS) is a sulfur compound of importance for the organoleptic properties of beer, especially some lager beers. Synthesis of DMS during beer production occurs partly during wort production and partly during fermentation. Methionine sulfoxide reductases are the enzymes responsible for reduction of oxidized cellular methionines. These enzymes have been suggested to be able to reduce dimethyl sulfoxide (DMSO) as well, with DMS as the product. A gene for an enzymatic activity lead...

  17. Co-Consumption of Methanol and Succinate by Methylobacterium extorquens AM1

    Science.gov (United States)

    Peyraud, Rémi; Kiefer, Patrick; Christen, Philipp; Portais, Jean-Charles; Vorholt, Julia A.

    2012-01-01

    Methylobacterium extorquens AM1 is a facultative methylotrophic Alphaproteobacterium and has been subject to intense study under pure methylotrophic as well as pure heterotrophic growth conditions in the past. Here, we investigated the metabolism of M. extorquens AM1 under mixed substrate conditions, i.e., in the presence of methanol plus succinate. We found that both substrates were co-consumed, and the carbon conversion was two-thirds from succinate and one-third from methanol relative to mol carbon. 13C-methanol labeling and liquid chromatography mass spectrometry analyses revealed the different fates of the carbon from the two substrates. Methanol was primarily oxidized to CO2 for energy generation. However, a portion of the methanol entered biosynthetic reactions via reactions specific to the one-carbon carrier tetrahydrofolate. In contrast, succinate was primarily used to provide precursor metabolites for bulk biomass production. This work opens new perspectives on the role of methylotrophy when substrates are simultaneously available, a situation prevailing under environmental conditions. PMID:23133625

  18. Succinate-induced neuronal mitochondrial fission and hexokinase II malfunction in ischemic stroke: Therapeutical effects of kaempferol.

    Science.gov (United States)

    Wu, Bin; Luo, Hong; Zhou, Xu; Cheng, Cai-Yi; Lin, Lin; Liu, Bao-Lin; Liu, Kang; Li, Ping; Yang, Hua

    2017-09-01

    Mitochondrial dysfunction is known as one of causative factors in ischemic stroke, leading to neuronal cell death. The present work was undertaken to investigate whether succinate induces neuron apoptosis by regulating mitochondrial morphology and function. In neurons, oxygen-glucose deprivation induced succinate accumulation due to the reversal of succinate dehydrogenase (SDH) activation, leading to mitochondrial fission. Kaempferol inhibited mitochondrial fission and maintained mitochondrial HK-II through activation of Akt, and thereby protected neurons from succinate-mediated ischemi injury. Knockdown of Akt2 with siRNA diminished the effect of kaempferol, indicating that kaempferol suppressed dynamin-related protein 1 (Drp1) activation and promoted HK-II mitochondrial binding dependently on Akt. Moreover, we demonstrated that kaempferol potentiated autophagy during oxygen and glucose deprivation, contributing to protecting neuron survival against succinate insult. In vivo, oral administration of kaempferol in mice attenuated the infract volume after ischemic and reperfusion (I/R) injury and reproduced the similar mitochondrial protective effect in the brain infract area. This study indicates that succinate accumulation plays a pivotal role in I/R injury-induced neuronal mitochondrial dysfunction, and suggests that modulation of Drp1 phosphorylation might be potential therapeutic strategy to protect neuron mitochondrial integrity and treat ischemic stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Synthesis of Dimethyl Glutarate from Cyclobutanone and Dimethyl Carbonate over Solid Base Catalysts

    International Nuclear Information System (INIS)

    Zhi, Chen; Dudu, Wu

    2012-01-01

    A facile route for the synthesis of dimethyl glutarate (DMG) from cyclobutanone and dimethyl carbonate (DMC) in the presence of solid base catalysts has been developed. It was found that the intermediate carbomethoxycyclobutanone (CMCB) was produced from cyclobutanone with DMC in the first step, and then CMCB was further converted to DMG by reacting with a methoxide group. The role of the basic catalysts can be mainly ascribed to the activation of cyclobutanone via the abstraction of a proton in the α-position by base sites, and solid bases with moderate strength, such as MgO, favor the formation of DMG

  20. Synthesis of Dimethyl Glutarate from Cyclobutanone and Dimethyl Carbonate over Solid Base Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zhi, Chen; Dudu, Wu [Guangdong Medical College, Dongguan (China)

    2012-06-15

    A facile route for the synthesis of dimethyl glutarate (DMG) from cyclobutanone and dimethyl carbonate (DMC) in the presence of solid base catalysts has been developed. It was found that the intermediate carbomethoxycyclobutanone (CMCB) was produced from cyclobutanone with DMC in the first step, and then CMCB was further converted to DMG by reacting with a methoxide group. The role of the basic catalysts can be mainly ascribed to the activation of cyclobutanone via the abstraction of a proton in the {alpha}-position by base sites, and solid bases with moderate strength, such as MgO, favor the formation of DMG

  1. Citrate and succinate uptake by potato mitochondria

    International Nuclear Information System (INIS)

    Jung, D.W.; Laties, G.G.

    1979-01-01

    Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

  2. 40 CFR 721.6167 - Piperdinium, 1,1-dimethyl-, chloride.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Piperdinium, 1,1-dimethyl-, chloride... Substances § 721.6167 Piperdinium, 1,1-dimethyl-, chloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as piperdinium, 1,1-dimethyl-, chloride. (PMN...

  3. Synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 (dimethyl-1-1 biguanide) hydrochloride; Synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 (dimethyl-1-1 biguanide)

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, M; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    A description of the synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 hydrochloride passing through the {sup 14}C{sub 2} dicyandiamide. The overall yield with respect to Ba{sup 14}CO{sub 3} is 38 per cent. (author) [French] Description de la synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 par l'intermediaire de la dicyandiamide {sup 14}C{sub 2}. Le rendement global par rapport a {sup 14}CO{sub 3}Ba est de 38 pour cent. (auteur)

  4. Volatility of Organic Aerosol: Evaporation of Ammonium Sulfate/Succinic Acid Aqueous Solution Droplets

    Science.gov (United States)

    2013-01-01

    Condensation and evaporation modify the properties and effects of atmospheric aerosol particles. We studied the evaporation of aqueous succinic acid and succinic acid/ammonium sulfate droplets to obtain insights on the effect of ammonium sulfate on the gas/particle partitioning of atmospheric organic acids. Droplet evaporation in a laminar flow tube was measured in a Tandem Differential Mobility Analyzer setup. A wide range of droplet compositions was investigated, and for some of the experiments the composition was tracked using an Aerosol Mass Spectrometer. The measured evaporation was compared to model predictions where the ammonium sulfate was assumed not to directly affect succinic acid evaporation. The model captured the evaporation rates for droplets with large organic content but overestimated the droplet size change when the molar concentration of succinic acid was similar to or lower than that of ammonium sulfate, suggesting that ammonium sulfate enhances the partitioning of dicarboxylic acids to aqueous particles more than currently expected from simple mixture thermodynamics. If extrapolated to the real atmosphere, these results imply enhanced partitioning of secondary organic compounds to particulate phase in environments dominated by inorganic aerosol. PMID:24107221

  5. Biotechnological route for sustainable succinate production utilizing oil palm frond and kenaf as potential carbon sources.

    Science.gov (United States)

    Luthfi, Abdullah Amru Indera; Manaf, Shareena Fairuz Abdul; Illias, Rosli Md; Harun, Shuhaida; Mohammad, Abdul Wahab; Jahim, Jamaliah Md

    2017-04-01

    Due to the world's dwindling energy supplies, greater thrust has been placed on the utilization of renewable resources for global succinate production. Exploration of such biotechnological route could be seen as an act of counterbalance to the continued fossil fuel dominance. Malaysia being a tropical country stands out among many other nations for its plenty of resources in the form of lignocellulosic biomass. To date, oil palm frond (OPF) contributes to the largest fraction of agricultural residues in Malaysia, while kenaf, a newly introduced fiber crop with relatively high growth rate, holds great potential for developing sustainable succinate production, apart from OPF. Utilization of non-food, inexhaustible, and low-cost derived biomass in the form of OPF and kenaf for bio-based succinate production remains largely untapped. Owing to the richness of carbohydrates in OPF and kenaf, bio-succinate commercialization using these sources appears as an attractive proposition for future sustainable developments. The aim of this paper was to review some research efforts in developing a biorefinery system based on OPF and kenaf as processing inputs. It presents the importance of the current progress in bio-succinate commercialization, in addition to describing the potential use of different succinate production hosts and various pretreatments-saccharifications under development for OPF and kenaf. Evaluations on the feasibility of OPF and kenaf as fermentation substrates are also discussed.

  6. Investigation of uranyl phosphite interaction with some amides

    International Nuclear Information System (INIS)

    Avduevskaya, K.A.; Ragulina, N.B.; Rozanov, I.A.; Mukhajlov, Yu.N.; Kanishcheva, A.S.; Grevtseva, T.G.

    1981-01-01

    Uranyl (amide) phosphitocomplexes of [UO 2 HPO 3 H 2 OAA]xH 2 O, [UO 2 HPO 3 (AA) 2 ], [UO 2 HPO 3 H 2 O DMC], [UO 2 HPO 3 H 2 ODMFA], [UO 2 HPO 3 DAMA] and UO 2 HPO 3 x2FAxH 2 O compositions, where AA-acetamide; DMC-N, N-dimetyl carbamide, DMFA-dimetyl formamide; DAMA-diamide of malonic acid; FA-formamide, are separated, identified and investigated. Derivatives of mono substituted uranyl phosphite of UO 2 (H 2 PO 3 ) 2 x2FA and [UO 2 (H 2 PO 3 ) 2 H 2 O]x2TMC composition (where TMC-tetramethyl carbamide), are synthesized. Structures of complexes with DAMA, TMC, DMFA and acid dimethyl-ammonium diphosphitouranylate-(CH 3 ] 2 NH 2 x[UO 2 (HPO 3 ) 3 (H 2 PO 3 )] are investigated [ru

  7. Chalcogen-containing oxazolines in the palladium-catalyzed asymmetric allylic alkylation

    Directory of Open Access Journals (Sweden)

    Braga Antonio L.

    2006-01-01

    Full Text Available A comparative study about the ability of chiral chalcogen-containing oxazolines to act as chiral ligands in the palladium-catalyzed allylic alkylation of rac-1,3-diphenyl-2-propenyl acetate with dimethyl malonate is reported. Differences in the catalytic performance are observed with sulfur, selenium and tellurium analogues.

  8. Dimethyl ether as a drift-chamber gas

    International Nuclear Information System (INIS)

    Bari, G.; Basile, M.; Bonvicini, G.; Cara Romeo, G.; Casaccia, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; D'Ali, G.; Del Papa, C.; Focardi, S.; Iacobucci, G.; Maccarrone, G.; Massam, T.; Motta, F.; Nania, R.; Palmonari, F.; Prisco, G.; Sartorelli, G.; Susinno, G.; Votano, L.; Zichichi, A.; Istituto Nazionale di Fisica Nucleare, Bologna; European Organization for Nuclear Research, Geneva; Istituto Nazionale di Fisica Nucleare, Frascati; Michigan Univ., Ann Arbor; Palermo Univ.

    1986-01-01

    We have continued the testing of dimethyl ether as a drift-chamber gas in order to improve the understanding of its properties. In particular, we report on measurement accuracy, on systematic effects, and some preliminary data on the ageing of a detector filled with dimethyl ether. (orig.)

  9. Succinate, iron chelation, and monovalent cations affect the transformation efficiency of Acinetobacter baylyi ATCC 33305 during growth in complex media.

    Science.gov (United States)

    Leong, Colleen G; Boyd, Caroline M; Roush, Kaleb S; Tenente, Ricardo; Lang, Kristine M; Lostroh, C Phoebe

    2017-10-01

    Natural transformation is the acquisition of new genetic material via the uptake of exogenous DNA by competent bacteria. Acinetobacter baylyi is model for natural transformation. Here we focus on the natural transformation of A. baylyi ATCC 33305 grown in complex media and seek environmental conditions that appreciably affect transformation efficiency. We find that the transformation efficiency for A. baylyi is a resilient characteristic that remains high under most conditions tested. We do find several distinct conditions that alter natural transformation efficiency including addition of succinate, Fe 2+ (ferrous) iron chelation, and substitution of sodium ions with potassium ones. These distinct conditions could be useful to fine tune transformation efficiency for researchers using A. baylyi as a model organism to study natural transformation.

  10. Amorphous/crystal and polymer/filler interphases in biocomposites from poly(butylene succinate)

    Energy Technology Data Exchange (ETDEWEB)

    Signori, Francesca [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy); Pelagaggi, Martina [Universita di Pisa - Dipartimento di Chimica e Chimica Industriale, Via Risorgimento 35, I-56126 Pisa (Italy); Bronco, Simona [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy); Righetti, Maria Cristina, E-mail: righetti@ipcf.cnr.it [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer The existence of intermolecular interactions between poly(butylene succinate) and hemp fibres was proved from specific heat capacities data. Black-Right-Pointing-Pointer Different degrees of mobility of the poly(butylene succinate) amorphous segments were evidenced at the amorphous/crystal interphase. Black-Right-Pointing-Pointer Devitrification of the rigid amorphous fraction in poly(butylene succinate) was found to occur before and simultaneously with the fusion. - Abstract: Poly(butylene succinate)-hemp composites (PBS-hemp), with hemp content in the range 0-40 wt.%, were prepared in the melt and characterized. This paper focuses on the detailed analysis of the thermal behaviour of the PBS-hemp composites, investigated by differential scanning calorimetry (DSC), to enlighten the polymer/fibre interphase features. The occurrence of specific intermolecular interactions between PBS and hemp was assessed from specific heat capacity data. Different degrees of mobility of the PBS amorphous segments were found at the amorphous/crystal interphases. A broadening of the bulk glass transition was observed, and attributed to the presence of polymer segments slightly constrained. Moreover, a rigid amorphous fraction that devitrifies at temperatures higher than the bulk glass transition, partly before the melting region and partly simultaneously with the fusion, was observed and quantified, and attributed to the presence of major constraints probably occurring in geometrically restricted areas.

  11. [Effect of L-arginine and the nitric oxide synthase blocker L-NNA on calcium capacity in rat liver mitochondria with differing resistance to hypoxia].

    Science.gov (United States)

    Kurhaliuk, N M; Ikkert, O V; Vovkanych, L S; Horyn', O V; Hal'kiv, M O; Hordiĭ, S K

    2001-01-01

    The effect of L-arginine and blockator of nitric oxide synthase L-NNA on processes of calcium mitochondrial capacity in liver with different resistance to hypoxia in the experiments with Wistar rats has been studied using the followrng substrates of energy support: succinic, alpha-ketoglutaric acids, alpha-ketolutarate and inhibitor succinatedehydrogenase malonate. As well we used substrates mixtures combination providing for activation of aminotransferase mechanism: glutamate and piruvate, glutamate and malate. It has been shown that L-arginine injection increases calcium mitochondrial capacity of low resistant rats using as substrates the succinate and alpha-ketoglutarate to control meanings of high resistance rats. Effects of donors nitric oxide on this processes limit NO-synthase inhibitor L-NNA.

  12. Selectivity control of carbonylation of methanol to dimethyl oxalate and dimethyl carbonate over gold anode by electrochemical potential.

    Science.gov (United States)

    Funakawa, Akiyasu; Yamanaka, Ichiro; Takenaka, Sakae; Otsuka, Kiyoshi

    2004-05-05

    New and unique electrocatalysis of gold for the carbonylation of methanol to dimethyl oxalate (DMO) and dimethyl carbonate (DMC) was found. The selectivity to DMO and DMC could be controlled over gold anode by electrochemical potential, as you like. Drastic changes of gold electrocatalysis was due to changes of the oxidation state of gold, Au0 or Au3+.

  13. Structural and magnetic studies on copper succinate dihydrate

    Indian Academy of Sciences (India)

    The four bis-bidendate succinate anions form syn–syn bridges among two copper atomsto form a polymeric two-dimensional chain. From room temperature vibrating sample magnetometer (VSM) studies themagnetic moment of the material is calculated as 1.35 Bohr magneton (BM), indicating antiferromagnetic interaction ...

  14. Krebs cycle metabolite profiling for identification and stratification of pheochromocytomas/paragangliomas due to succinate dehydrogenase deficiency

    NARCIS (Netherlands)

    Richter, S; Peitzsch, M.; Rapizzi, E.; Lenders, J.W.M.; Qin, N.; Cubas, A.A. de; Schiavi, F.; Rao, J.U.; Beuschlein, F.; Quinkler, M.; Timmers, H.J.L.M.; Opocher, G.; Mannelli, M.; Pacak, K.; Robledo, M.; Eisenhofer, G.

    2014-01-01

    CONTEXT: Mutations of succinate dehydrogenase A/B/C/D genes (SDHx) increase susceptibility to development of pheochromocytomas and paragangliomas (PPGLs), with particularly high rates of malignancy associated with SDHB mutations. OBJECTIVE: We assessed whether altered succinate dehydrogenase

  15. Radiation-induced catalysis of fatty acids adsorbed onto clay minerals

    International Nuclear Information System (INIS)

    Negron-Mendoza, A.; Ramos-Bernal, S.; Colin-Garcia, M.; Mosqueira, F.G.

    2015-01-01

    We studied the behavior of small fatty (acetic acid) and dicarboxylic acids (succinic and malonic acids) adsorbed onto Na + -montmorillonite (a clay mineral) and exposed to gamma radiation. A decarboxylation reaction was found to predominate when the clay was present. This preferential synthesis promoted the formation of a compound with one less carbon atom than its target compound. In the system without clay, dimerization was the predominate outcome following radiolysis. (author)

  16. Spurious cooperativity in alkylated succinic acids

    Science.gov (United States)

    Ben-Naim, A.

    1998-03-01

    The proton-proton correlation, as measured by the ratio between the second and the first dissociation constants of dibasic acid, is sometimes very large and far beyond what could be explained by electrostatic theories. We propose a novel interpretation of this phenomenon based on the idea of spurious cooperativity. The general theoretical framework underlying the onset of spurious cooperativity is developed first. The basic result is that whenever a binding (or dissociating) two-site (or more) system splits into a mixture of noninterconverting isomers the binding isotherm (or the titration curve) behaves as if it is more negatively cooperative compared with the genuine cooperativities of the individual isomer. The theory is applied to a specific system of α-α' dialkyl succinic acid. It is known that the Meso form of these alkylated derivatives show a normal correlation of the same order of magnitude as in succinic acid. On the other hand, the Racemic form of these alkylated derivatives shows anomalous strong negative correlations when the alkyl groups become large (e.g., isopropyl and tert butyl). It is shown that the theory of spurious cooperativity can explain the different behavior of the Racemic and the Meso forms, as well as the onset of anomalous strong negative correlations when the alkyl groups become large.

  17. Succinic acid production from acid hydrolysate of corn fiber by Actinobacillus succinogenes.

    Science.gov (United States)

    Chen, Kequan; Jiang, Min; Wei, Ping; Yao, Jiaming; Wu, Hao

    2010-01-01

    Dilute acid hydrolysate of corn fiber was used as carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. The optimized hydrolysis conditions were obtained by orthogonal experiments. When corn fiber particles were of 20 mesh in size and treated with 1.0% sulfuric acid at 121 degrees C for 2 h, the total sugar yield could reach 63.3%. It was found that CaCO(3) neutralization combined with activated carbon adsorption was an effective method to remove fermentation inhibitors especially furfural that presented in the acid hydrolysate of corn fiber. Only 5.2% of the total sugar was lost, while 91.9% of furfural was removed. The yield of succinic acid was higher than 72.0% with the detoxified corn fiber hydrolysate as the carbon source in anaerobic bottles or 7.5 L fermentor cultures. It was proved that the corn fiber hydrolysate could be an alternative to glucose for the production of succinic acid by A. succinogenes NJ113.

  18. Binary and ternary solid-liquid phase equilibrium for the systems formed by succinic acid, urea and diethylene glycol: Determination and modelling

    International Nuclear Information System (INIS)

    Li, Yanxun; Li, Congcong; Han, Shuo; Zhao, Hongkun

    2017-01-01

    Highlights: • Solubility of succinic acid in diethylene glycol was determined. • Solubility of succinic acid + urea + diethylene glycol was determined. • Three ternary phase diagrams were constructed for the ternary system. • The ternary phase diagrams were correlated using NRTL model. - Abstract: In this work, the solid-liquid phase equilibrium for binary system of succinic acid + diethylene glycol at the temperatures ranging from (298.15 to 333.15) K and ternary system of (succinic acid + urea + diethylene glycol) at 298.15 K, 313.15 K and 333.15 K was built by using the isothermal saturation method under atmospheric pressure (101.2 kPa), and the solubilities were determined by a high-performance liquid chromatography. The solid-phases formed in the ternary system of ((succinic acid + urea + diethylene glycol)) were confirmed by Schreinemaker’s method of wet residue, which corresponded to urea, succinic acid, and adduct 2:1 urea-succinic acid (mole ratio). Three isothermal phase diagrams for the ternary system were constructed based on the measured mutual solubility. Each isothermal phase diagram included six crystallization fields, three invariant curves, two invariant points and two co-saturated points. The crystalline region of adduct 2:1 urea-succinic acid is larger than those of the other two solids. The solubility of succinic acid in diethylene glycol was correlated with the modified Apelblat equation, λh equation and NRTL model; and the mutual solubility of the ternary ((succinic acid + urea + diethylene glycol)) system was correlated and calculated by the NRTL model. The interaction parameters’ values of succinic acid-urea were acquired. The value of RMSD was 7.11 × 10 −3 for the ternary system. The calculation results had good agreement with the experiment values. Furthermore, the densities of equilibrium liquid phase were acquired. The phase diagrams and the thermodynamic model of the ternary system could provide the basis for design of

  19. Fragrance material review on 1-(2,4-dimethyl-3-cyclohexenyl)-2,2-dimethylpropan-1-one.

    Science.gov (United States)

    Scognamiglio, J; Letizia, C S; Api, A M

    2013-12-01

    A toxicologic and dermatologic review of 1-(2,4-dimethyl-3-cyclohexenyl)-2,2-dimethylpropan-1-one when used as a fragrance ingredient is presented. 1-(2,4-Dimethyl-3-cyclohexenyl)-2,2-dimethylpropan-1-one is a member of the fragrance structural group Alkyl Cyclic Ketones. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1-(2,4-dimethyl-3-cyclohexenyl)-2,2-dimethylpropan-1-one were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, sensitization, and genotoxicity data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013. A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones When Used as Fragrance Ingredients (submitted for publication)) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

    Science.gov (United States)

    Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

    2017-02-01

    Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Integrated production of cellulosic bioethanol and succinic acid from industrial hemp in a biorefinery concept

    DEFF Research Database (Denmark)

    Kuglarz, Mariusz; Alvarado-Morales, Merlin; Karakashev, Dimitar Borisov

    2016-01-01

    The aim of this study was to develop integrated biofuel (cellulosic bioethanol) and biochemical (succinic acid) production from industrial hemp (Cannabis sativa L.) in a biorefinery concept. Two types of pretreatments were studied (dilute-acid and alkaline oxidative method). High cellulose recovery...... productivity. With respect to succinic acid production, the highest productivity was obtained after liquid fraction fermentation originated from steam treatment with 1.5% of acid. The mass balance calculations clearly showed that 149 kg of EtOH and 115 kg of succinic acid can be obtained per 1 ton of dry hemp....... Results obtained in this study clearly document the potential of industrial hemp for a biorefinery....

  2. Metabolic Engineering of Saccharomyces cerevisiae Microbial Cell Factories for Succinic Acid Production

    DEFF Research Database (Denmark)

    Otero, José Manuel; Nielsen, Jens; Olsson, Lisbeth

    2007-01-01

    anhydride. There are several biomass platforms, all prokaryotic, for succinic acid production; however, overproduction of succinic acid in S. cerevisiae offers distinct process advantages. For example, S. cerevisiae has been awarded GRAS status for use in human consumables, grows well at low p......H significantly minimizing purification and acidification costs associated with organic acid production, and can utilize diverse carbon substrates in chemically defined medium. S. cerevisiae offers the unique advantage of being the most well characterized eukaryotic expression system. Here we describe the use...

  3. Enterobacter sp. LU1 as a novel succinic acid producer - co-utilization of glycerol and lactose.

    Science.gov (United States)

    Podleśny, Marcin; Jarocki, Piotr; Wyrostek, Jakub; Czernecki, Tomasz; Kucharska, Jagoda; Nowak, Anna; Targoński, Zdzisław

    2017-03-01

    Succinic acid is an important C4-building chemical platform for many applications. A novel succinic acid-producing bacterial strain was isolated from goat rumen. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the genus Enterobacter. This is the first report of a wild bacterial strain from the genus Enterobacter that is capable of efficient succinic acid production. Co-fermentation of glycerol and lactose significantly improved glycerol utilization under anaerobic conditions, debottlenecking the utilization pathway of this valuable biodiesel waste product. Succinic acid production reached 35 g l -1 when Enterobacter sp. LU1 was cultured in medium containing 50 g l -1 of glycerol and 25 g l -1 of lactose as carbon sources. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  4. Determination of dimethyl selenide and dimethyl sulphide compounds causing off-flavours in bottled mineral waters.

    Science.gov (United States)

    Guadayol, Marta; Cortina, Montserrat; Guadayol, Josep M; Caixach, Josep

    2016-04-01

    Sales of bottled drinking water have shown a large growth during the last two decades due to the general belief that this kind of water is healthier, its flavour is better and its consumption risk is lower than that of tap water. Due to the previous points, consumers are more demanding with bottled mineral water, especially when dealing with its organoleptic properties, like taste and odour. This work studies the compounds that can generate obnoxious smells, and that consumers have described like swampy, rotten eggs, sulphurous, cooked vegetable or cabbage. Closed loop stripping analysis (CLSA) has been used as a pre-concentration method for the analysis of off-flavour compounds in water followed by identification and quantification by means of GC-MS. Several bottled water with the aforementioned smells showed the presence of volatile dimethyl selenides and dimethyl sulphides, whose concentrations ranged, respectively, from 4 to 20 ng/L and from 1 to 63 ng/L. The low odour threshold concentrations (OTCs) of both organic selenide and sulphide derivatives prove that several objectionable odours in bottled waters arise from them. Microbial loads inherent to water sources, along with some critical conditions in water processing, could contribute to the formation of these compounds. There are few studies about volatile organic compounds in bottled drinking water and, at the best of our knowledge, this is the first study reporting the presence of dimethyl selenides and dimethyl sulphides causing odour problems in bottled waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Genome-scale modeling enables metabolic engineering of Saccharomyces cerevisiae for succinic acid production.

    Science.gov (United States)

    Agren, Rasmus; Otero, José Manuel; Nielsen, Jens

    2013-07-01

    In this work, we describe the application of a genome-scale metabolic model and flux balance analysis for the prediction of succinic acid overproduction strategies in Saccharomyces cerevisiae. The top three single gene deletion strategies, Δmdh1, Δoac1, and Δdic1, were tested using knock-out strains cultivated anaerobically on glucose, coupled with physiological and DNA microarray characterization. While Δmdh1 and Δoac1 strains failed to produce succinate, Δdic1 produced 0.02 C-mol/C-mol glucose, in close agreement with model predictions (0.03 C-mol/C-mol glucose). Transcriptional profiling suggests that succinate formation is coupled to mitochondrial redox balancing, and more specifically, reductive TCA cycle activity. While far from industrial titers, this proof-of-concept suggests that in silico predictions coupled with experimental validation can be used to identify novel and non-intuitive metabolic engineering strategies.

  6. Crystallization behavior of partially miscible biodegradable poly(butylene succinate)/poly(ethylene succinate) blends

    International Nuclear Information System (INIS)

    He, Yi-Song; Zeng, Jian-Bing; Li, Shao-Long; Wang, Yu-Zhong

    2012-01-01

    Graphical abstract: Crystallization rate of PBS in the blends decreased first and then increased with increase in PES content, and that of PES increased steadily with increase in PBS content. The rich component formed a continuous phase and the other formed a dispersed phase of the blend. Crystal structures of PBS and PES were almost unchanged after blending with each other. Highlights: ► PBS/PES blend systems are partially miscible. ► Blending did not change the crystallization mechanisms of PBS and PES not affects the crystallization rates. ► The rich component formed the continuous phase while the poor component formed the dispersed phase of the blends. ► Crystal structures of PBS and PES were almost unchanged after blending with each other. - Abstract: Biodegradable blend of poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) was prepared by solution blending and casting method with chloroform as a mutual solvent. Miscibility of the blends was investigated by differential scanning calorimetry (DSC). The results indicated that PBS and PES were partially miscible. Crystallization kinetics, crystalline morphology and crystal structure of the blends were studied by DSC, polarized optical microscope (POM), and wide-angle X-ray diffraction (WAXD), respectively. Nonisothermal and isothermal crystallization kinetics suggested that the crystallizability of PBS in the blends decreased first and then increased with increase in PES content, and that of PES increased steadily with increase in PBS content. POM observation illustrated that the rich component formed a continuous phase and the other formed a dispersed phase. The results of WAXD indicated that the crystal structures of PBS and PES were almost unchanged before and after blending, since the positions of characteristic diffraction peaks of both components remain almost unchanged.

  7. Design, synthesis and evaluation of dialkyl 4-(benzo[d][1,3]dioxol-6-yl)-1,4-dihydro-2,6-dimethyl-1-substituted pyridine-3,5-dicarboxylates as potential anticonvulsants and their molecular properties prediction.

    Science.gov (United States)

    Prasanthi, G; Prasad, K V S R G; Bharathi, K

    2013-08-01

    The present study is on the development of dialkyl 4-(benzo[d][1,3]dioxol-6-yl)-1,4-dihydro-2,6-dimethyl-1-substituted pyridine-3,5-dicarboxylate derivatives as isosteric analogues of isradipine and nifedipine, by the replacement of benzofurazanyl and 2-nitrophenyl groups respectively with benzo[d][1,3]dioxo-6-yl group, as potential anticonvulsants. Fivfteen new derivatives (8a-8o) were synthesized and tested for anticonvulsant activity using maximal electroshock and subcutaneous pentylenetetrazole induced seizure methods. Compound 8f possessing free NH group in 1,4-dihydropyridine ring, diethyl ester functionality at the positions 3 and 5 showed significant anticonvulsant and antioxidant activities. This was also supported by molecular properties prediction data. Selected compounds were evaluated for antinociceptive activity in capsaicin induced nociception assay at 10 mg/kg body weight, but displayed no significant activity at the tested dose. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. Succinic acid dihydrazide: a convenient N,N-double block for the synthesis of symmetrical and non-symmetrical succinyl-bis[5-trifluoro(chloro)methyl-1H-pyrazoles

    International Nuclear Information System (INIS)

    Bonacorso, Helio G.; Cechinel, Cleber A.; Pittaluga, Everton P.; Ferla, Adriana; Porte, Liliane M.F; Martins, Marcos A.P; Zanatta, Nilo

    2010-01-01

    This paper describes the conventional regioselective synthesis of a series of new succinyl spacer bis-(3,5-substituted 2-pyrazolines and 1H-pyrazoles), namely; 1,4-bis[5-(trifluoromethyl)-5- hydroxy-4,5-dihydro-1H-pyrazol-1-yl]butane-1,4-diones (46-88%) and the respective dehydrated system (60-78%), new 1-[5-(trifluoromethyl)-5-hydroxy-4,5-dihydro-1H-pyrazol-1-yl]-4- oxobutane hydrazides (52-81%) and the non-symmetrical 2-pyrazolines derivatives thereof as 1-[5-(trifluoromethyl)- 5-hydroxy-4,5-dihydro-1H-pyrazol-1-yl)-4-(5-(trichloromethyl)-5-hydroxy- 4,5-dihydro-1H-pyrazol-1-yl]butane-1,4-diones (75-91%). All succinyl substituted bispyrazoles were obtained from the cyclocondensation reactions of 4-substituted 4-alkoxy-1,1,1-trihaloalk-3- en-2-ones, where the 4-substituents are H, Me, Ph, 4-FC 6 H 4 , 4-ClC 6 H 4 , 4-OMeC 6 H 4 , 4-NO 2 C 6 H 4 , 1-naphthyl and 2-furyl, with succinic acid dihydrazide in ethanol as solvent under controlled reaction conditions. (author)

  9. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Semelsberger

    2004-10-01

    The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

  10. (2E-3-(3,5-Dimethyl-1-phenyl-1H-pyrazol-4-yl-1-(2,5-dimethyl-3-thienylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Salman A. Khan

    2010-04-01

    Full Text Available The title compound, (2E-3-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl-1-(2,5-dimethyl-3-thienylprop-2-en-1-one (3 was synthesized in high yield by aldol condensation of 3-acetyl-2,5-dimethylthiophene and 3,5-dimethyl-1-phenylpyrazole-4-carboxaldehyde in ethanolic NaOH at room temperature. Its structure was fully characterized by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral analysis.

  11. Effect of atmospheric organic complexation on iron-bearing dust solubility

    OpenAIRE

    Paris , R.; Desboeufs , K. V.

    2013-01-01

    International audience; Recent studies reported that the effect of organic complexation may be a potentially important process to be considered by models estimating atmospheric iron flux to the ocean. In this study, we investigated this process effect by a series of dissolution experiments on iron-bearing dust in the presence or the absence of various organic compounds (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of hum...

  12. Natural history of succinic semialdehyde dehydrogenase deficiency through adulthood

    NARCIS (Netherlands)

    Lapalme-Remis, S.; Lewis, E.C.; De Meulemeester, C.; Chakraborty, P.; Gibson, K.M.; Torres, C.; Guberman, A.; Salomons, G.; Jakobs, C.; Ali-Ridha, A.; Parviz, M.; Pearl, P.L.

    2015-01-01

    Objective: The natural history of succinic semialdehyde dehydrogenase (SSADH) deficiency in adulthood is unknown; we elucidate the clinical manifestations of the disease later in life. Methods: A 63-year-old man with long-standing intellectual disability was diagnosed with SSADH deficiency following

  13. Multifunctional nanobiocomposite of Poly[(butylene succinate)-co-adipate] and clay

    CSIR Research Space (South Africa)

    Al-Thabaiti, SA

    2015-03-01

    Full Text Available The processing and characterization of multifunctional nanobiocomposite of biodegradable poly[(butylene succinate)-co-adipate] (PBSA) and organically modified synthetic fluorine mica (OSFM) are reported. The nanobiocomposite of PBSA with OSFM...

  14. cis-Bis(2,2′-bipyridine-κ2N,N′bis(dimethyl sulfoxide-κOzinc bis(tetraphenylborate dimethyl sulfoxide monosolvate

    Directory of Open Access Journals (Sweden)

    Stefania Tomyn

    2011-12-01

    Full Text Available In the mononuclear title complex, [Zn(C10H8N22(C2H6OS2](C24H20B2·C2H6OS, the ZnII ion is coordinated by four N atoms of two bidentate 2,2′-bipyridine molecules and by the O atoms of two cis-disposed dimethyl sulfoxide molecules in a distorted octahedral geometry. The S atom and the methyl groups of one of the coordinated dimethyl sulfoxide molecules are disordered in a 0.509 (2:0.491 (2 ratio. The crystal packing is stabilized by C—H...O hydrogen bonds between the dimethyl sulfoxide solvent molecules and tetraphenylborate anions.

  15. Efficient production of succinic acid in immobilized fermentation with crude glycerol from Escherichia coli

    Directory of Open Access Journals (Sweden)

    Nik Nor Aziati, A.A.

    2017-10-01

    Full Text Available The increase in the price of commercial succinic acid has necessitated the need for its synthesis from waste materials such as glycerol. Glycerol residue is a waste product of Oleochemical production which is cheaply available and a very good source of carbon. The use of immobilized cells can further reduce the overall cost of the production process. This study primarily aims to produce succinic acid from glycerol residue through the use of immobilized Escherichia coli in a batch fermentation process. The parameters which affect bacterial fermentation process such as the mass substrate, temperature, inoculum size and duration of fermentation were screened using One-Factor-At-a-Time (OFAT method. The result of the screening process shows that a substrate (glycerol concentration of 30 g, inoculum size 20% v/v, and time 4 h produced the maximum succinic acid concentration of 117.99 g/L. The immobilized cells were found to be stable as well as retain their fermentative ability up to the 6th cycle of recycling, thereby presenting as an advantage over the free cell system. Therefore, conclude that using immobilized cells can contribute immensely to the cost-effective production of succinic acid from glycerol residue.

  16. CLINICAL AND ECONOMICAL ASSESSMENTS OF METOPROLOL TARTRATE/SUCCINATE USAGE IN PATIENTS WITH ISCHEMIC HEART DISEASE

    Directory of Open Access Journals (Sweden)

    M. V. Soura

    2008-01-01

    Full Text Available Clinical and clinicoeconomical studies review is presented as well as results of author’s comparative cost analysis on metoprolol tartrate (Betaloc and metoprolol succinate (Betaloc ZOK usage in patients with ischemic heart disease. Efficacy of metoprolol therapy is proven in randomized clinical studies in patients with angina and myocardial infarction (MI. In angina patients metoprolol prevents cardiac attacks, MI, reduces nitroglycerine consumption, increases exercise tolerability, prolongs the exercise time before ST segment depression (succinate better than tartrate, decrease of angina intensity. In MI patients metoprolol therapy reduces mortality, sudden death, recurring MI and the rate of early post MI angina attacks. Nowadays metoprolol is the only β-blocker having indication on secondary MI prevention. Besides for the present metoprolol succinate is the only β-blocker with proven direct antisclerosis effect. According to Swedish clinicoeconomical study in patients after MI secondary prevention with metoprolol therapy saves the costs in comparison with placebo. American clinicoeconomical model of metoprolol and atenolol usage in all patients with MI could result in significant reduction in mortality and recurring MI rate, prolong the life and improve its quality, save financial resources. The cost of monthly treatment of angina patient with metoprolol tartrate (Betaloc and metoprolol succinate (Betaloc ZOK is 135 and 354 rubles, respectively. The price range of comparative β-blockers in ascending order is the following: atenolol (Atenolol Nicomed → metoprolol tartrate (Betaloc → metoprolol succinate (Betaloc ZOK → bisoprolol (Concor → nebivolol (Nebilet. In conclusion, metoprolol therapy is the one of mostly economically reasonable approach.

  17. [Effects of Light Near-Infrared Radiation on Rats Assessed by Succinate Dehydrogenase Activity in Lymphocytes on Blood Smears].

    Science.gov (United States)

    Khunderyakova, N V; Zakharchenko, A V; Zakharchenko, M V; Muller, H; Fedotcheva, I; Kondrashova, M N

    2015-01-01

    Biological effects of light near infrared radiation (850 nm), with modulation acoustic frequency of 101 Hz, was studied. The study was conducted on rats, the effect was recorded by succinate dehydrogenase activity in lymphocytes on the blood smear after administration of the activating dose of adrenaline, which simulates the state of the organism in the early stages of the pathogenic effects (stress). A pronounced regulating effect of infrared radiation on the activity of succinate dehydrogenase in animals activated by adrenaline was shown. Infrared radiation has a normalizing effect reducing the degree of inhibition or activation of the enzyme induced by adrenaline and had no effect on the control animals. Thus, by modulating the activity of succinate dehydrogenase infrared radiation regulates energy production in the mitochondria supported by the most powerful oxidation substrate--succinic acid, which is especially pronounced under stress.

  18. Design and Synthesis of Bis-amide and Hydrazide-containing Derivatives of Malonic Acid as Potential HIV-1 Integrase Inhibitors

    Directory of Open Access Journals (Sweden)

    Nouri Neamati

    2008-10-01

    Full Text Available HIV-1 integrase (IN is an attractive and validated target for the development of novel therapeutics against AIDS. In the search for new IN inhibitors, we designed and synthesized three series of bis-amide and hydrazide-containing derivatives of malonic acid. We performed a docking study to investigate the potential interactions of the title compounds with essential amino acids on the IN active site.

  19. Contribution of the tricarboxylic acid (TCA) cycle and the glyoxylate shunt in Saccharomyces cerevisiae to succinic acid production during dough fermentation.

    Science.gov (United States)

    Rezaei, Mohammad N; Aslankoohi, Elham; Verstrepen, Kevin J; Courtin, Christophe M

    2015-07-02

    Succinic acid produced by yeast during bread dough fermentation can significantly affect the rheological properties of the dough. By introducing mutations in the model S288C yeast strain, we show that the oxidative pathway of the TCA cycle and the glyoxylate shunt contribute significantly to succinic acid production during dough fermentation. More specifically, deletion of ACO1 and double deletion of ACO1 and ICL1 resulted in a 36 and 77% decrease in succinic acid levels in fermented dough, respectively. Similarly, double deletion of IDH1 and IDP1 decreased succinic acid production by 85%, while also affecting the fermentation rate. By contrast, double deletion of SDH1 and SDH2 resulted in a two-fold higher succinic acid accumulation compared to the wild-type. Deletion of fumarate reductase activity (FRD1 and OSM1) in the reductive pathway of the TCA cycle did not affect the fermentation rate and succinic acid production. The changes in the levels of succinic acid produced by mutants Δidh1Δidp1 (low level) and Δsdh1Δsdh2 (high level) in fermented dough only resulted in small pH differences, reflecting the buffering capacity of dough at a pH of around 5.1. Moreover, Rheofermentometer analysis using these mutants revealed no difference in maximum dough height and gas retention capacity with the dough prepared with S288C. The impact of the changed succinic acid profile on the organoleptic or antimicrobial properties of bread remains to be demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Succinate-CoA ligase deficiency due to mutations in SUCLA2 and SUCLG1

    DEFF Research Database (Denmark)

    Carrozzo, Rosalba; Verrigni, Daniela; Rasmussen, Magnhild

    2016-01-01

    BACKGROUND: The encephalomyopathic mtDNA depletion syndrome with methylmalonic aciduria is associated with deficiency of succinate-CoA ligase, caused by mutations in SUCLA2 or SUCLG1. We report here 25 new patients with succinate-CoA ligase deficiency, and review the clinical and molecular findings...... deficiency of complexes I and IV, but normal histological and biochemical findings in muscle did not preclude a diagnosis of succinate-CoA ligase deficiency. In five patients, the urinary excretion of methylmalonic acid was only marginally elevated, whereas elevated plasma methylmalonic acid was consistently...

  1. Characterization and analysis of structural isomers of dimethyl methoxypyrazines in cork stoppers and ladybugs (Harmonia axyridis and Coccinella septempunctata).

    Science.gov (United States)

    Slabizki, Petra; Legrum, Charlotte; Meusinger, Reinhard; Schmarr, Hans-Georg

    2014-10-01

    The three constitutional isomers of dimethyl-substituted methoxypyrazines: 3,5-dimethyl-2-methoxypyrazine 1; 2,5-dimethyl-3-methoxypyrazine 2; and 2,3-dimethyl-5-methoxypyrazine 3 are potent flavor compounds with similar mass spectrometric, gas chromatographic, and nuclear magnetic resonance spectroscopic behavior. Therefore, unambiguous analytical determination is critical, particularly in complex matrices. The unequivocal identification of 1-3 could be achieved by homo- and heteronuclear NMR correlation experiments. The observed mass fragmentation for 1-3 is proposed and discussed, benefitting from synthesized partially deuterated 1 and 2. On common polar and apolar stationary phases used in gas chromatography (GC) 1 and 2 show similar behavior whereas 3 can be separated. In our focus on off-flavor analysis with respect to wine aroma, 1 has been described as a "moldy" off-flavor compound in cork and 2 as a constituent in Harmonia axyridis contributing to the so-called "ladybug taint," whereas 3 has not yet been described as a constituent of wine aroma. A successful separation of 1 and 2 could be achieved on octakis-(2,3-di-O-pentyl-6-O-methyl)-γ-cyclodextrin as stationary phase in GC. Applying heart-cut multidimensional GC analysis with tandem mass spectrometric detection we could confirm the presence of 1 as a "moldy" off-flavor compound in cork. However, in the case of Harmonia axyridis, a previous identification of 2 has to be reconsidered. In our experiments we identified the constitutional isomer 1, which was also found in Coccinella septempunctata, another species discussed with respect to the "ladybug taint." The analysis of such structurally related compounds is a demonstrative example for the importance of a chromatographic separation, as mass spectrometric data by itself could not guarantee the unequivocal identification.

  2. Spectrophotometric determination of copper in alkaline solutions and evaluation of some hydroxy-substituted 1,10-phenanthrolines as chromogenic reagents.

    Science.gov (United States)

    Dunbar, W E; Schilt, A A

    1972-09-01

    Seven new hydroxy-substituted 1,10-phenanthroline derivatives have been evaluated as chromogenic reagents for the determination of copper in strongly alkaline solution. The most sensitive of these, 2,9-dimethyl-4,7-dihydroxy-1,10-phenanthroline, has proven to be highly effective in a simple, rapid procedure for determining trace amounts of copper in sodium hydroxide, potassium carbonate, sodium phosphate or ammonium hydroxide.

  3. Influence of VO2+ ions on structural and optical properties of potassium succinate-succinic acid single crystal for non-linear optical applications

    Science.gov (United States)

    Juliet sheela, K.; Subramanian, P.

    2018-04-01

    A transparent and good optical quality semi organic single crystal of vanadium doped potassium succinate-succinic acid (KSSA) was synthesized by slow evaporation technique at room temperature. The structural perfection was supported by the powder XRD of the KSSA-VO2+ single crystal. Optical behavior of the material was discovered from the absorption and transmission spectra of UV-vis-NIR characterization. Functional group and presence of metal ion in the specimen are depicted from FTIR traces. From the photoluminescence studies, emission of wavelength in the violet region (418 nm) at the excitation of 243 nm could be ascertained. EDAX, SEM measurements identify presence of elements and pictures the step-line growth and the imperfection presents in the grown crystal. EPR analysis extracts the information about the local site symmetry around the impurity ion, molecular orbital coefficients, admixture coefficients and ground state wave function of VO2+ doped KSSA single crystal. Second harmonic generation (SHG) efficiency of the grown crystal was investigated to explore the NLO characteristic of the material.

  4. Acute environmental toxicity and persistence of DEM, a chemical agent simulant: Diethyl malonate. [Diethyl malonate

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, Shu-mei W.; Van Voris, P.; Wentsel, R.S.

    1990-05-01

    The purpose of the following chemical simulant studies is to assess the potential acute environmental effects and persistence of diethyl malonate (DEM). Deposition velocities for DEM to soil surfaces ranged from 0.04 to 0.2 cm/sec. For foliar surfaces, deposition velocities ranged from 0.0002 cm/sec at low air concentrations to 0.05 cm/sec for high dose levels. The residence times or half-lives of DEM deposited to soils was 2 h for the fast component and 5 to 16 h for the residual material. DEM deposited to foliar surfaces also exhibited biphasic depuration. The half-life of the short residence time component ranged from 1 to 3 h, while the longer time component had half-times of 16 to 242 h. Volatilization and other depuration mechanisms reduce surface contaminant levels in both soils and foliage to less than 1% of initial dose within 96 h. DEM is not phytotoxic at foliar mass loading levels of less than 10 {mu}m/cm{sup 2}. However, severe damage is evident at mass loading levels in excess of 17 {mu}g/cm{sup 2}. Tall fescue and sagebrush were more affected than was short-needle pine, however, mass loading levels were markedly different. Regrowth of tall fescue indicated that the effects of DEM are residual, and growth rates are affected only at higher mass loadings through the second harvest. Results from in vitro testing of DEM indicated concentrations below 500 {mu}g/g dry soil generally did not negatively impact soil microbial activity. Short-term effects of DEM were more profound on soil dehydrogenase activity than on soil phosphatase activity. No enzyme inhibition or enhancement was observed after 28 days in incubation. Results of the earthworm bioassay indicate survival to be 86 and 66% at soil doses of 107 and 204 {mu}g DEM/cm{sup 2}, respectively. At higher dose level, activity or mobility was judged to be affected in over 50% of the individuals. 21 refs., 10 figs., 15 tabs.

  5. Effects of dimethyl fumarate on neuroprotection and immunomodulation

    Directory of Open Access Journals (Sweden)

    Albrecht Philipp

    2012-07-01

    Full Text Available Abstract Background Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate is a promising novel oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. These effects are presumed to originate from a combination of immunomodulatory and neuroprotective mechanisms. We aimed to clarify whether neuroprotective concentrations of dimethyl fumarate have immunomodulatory effects. Findings We determined time- and concentration-dependent effects of dimethyl fumarate and its metabolite monomethyl fumarate on viability in a model of endogenous neuronal oxidative stress and clarified the mechanism of action by quantitating cellular glutathione content and recycling, nuclear translocation of transcription factors, and the expression of antioxidant genes. We compared this with changes in the cytokine profiles released by stimulated splenocytes measured by ELISPOT technology and analyzed the interactions between neuronal and immune cells and neuronal function and viability in cell death assays and multi-electrode arrays. Our observations show that dimethyl fumarate causes short-lived oxidative stress, which leads to increased levels and nuclear localization of the transcription factor nuclear factor erythroid 2-related factor 2 and a subsequent increase in glutathione synthesis and recycling in neuronal cells. Concentrations that were cytoprotective in neuronal cells had no negative effects on viability of splenocytes but suppressed the production of proinflammatory cytokines in cultures from C57BL/6 and SJL mice and had no effects on neuronal activity in multi-electrode arrays. Conclusions These results suggest that immunomodulatory concentrations of dimethyl fumarate can reduce oxidative stress without altering neuronal network activity.

  6. Temperature influence on the malonic acid decomposition in the Belousov-Zhabotinsky reaction

    Science.gov (United States)

    Blagojević, S. M.; Anić, S. R.; Čupić, Ž. D.; Pejić, N. D.; Kolar-Anić, Lj. Z.

    2009-09-01

    The kinetic investigations of the malonic acid decomposition (8.00 × 10-3 mol dm-3 ≤ [CH2(COOH)2]0 ≤ 4.30 × 10-2 mol dm-3) in the Belousov-Zhabotinsky (BZ) system in the presence of bromate, bromide, sulfuric acid and cerium sulfate, were performed in the isothermal closed well stirred reactor at different temperatures (25.0°C ≤ T ≤ 45.0°C). The formal kinetics of the overall BZ reaction, and particularly kinetics in characteristic periods of BZ reaction, based on the analyses of the bromide oscillograms, was accomplished. The evolution as well as the rate constants and the apparent activation energies of the reactions, which exist in the preoscillatory and oscillatory periods, are also successfully calculated by numerical simulations. Simulations are based on the model including the Br2O species.

  7. Catalytic ozonation not relying on hydroxyl radical oxidation: A selective and competitive reaction process related to metal-carboxylate complexes

    KAUST Repository

    Zhang, Tao

    2014-01-01

    Catalytic ozonation following non-hydroxyl radical pathway is an important technique not only to degrade refractory carboxylic-containing organic compounds/matter but also to avoid catalyst deactivation caused by metal-carboxylate complexation. It is unknown whether this process is effective for all carboxylates or selective to special molecule structures. In this work, the selectivity was confirmed using O3/(CuO/CeO2) and six distinct ozone-resistant probe carboxylates (i.e., acetate, citrate, malonate, oxalate, pyruvate and succinate). Among these probe compounds, pyruvate, oxalate, and citrate were readily degraded following the rate order of oxalate>citrate>pyruvate, while the degradation of acetate, malonate, and succinate was not promoted. The selectivity was independent on carboxylate group number of the probe compounds and solution pH. Competitive degradation was observed for carboxylate mixtures following the preference order of citrate, oxalate, and finally pyruvate. The competitive degradation was ascribed to competitive adsorption on the catalyst surface. It was revealed that the catalytically degradable compounds formed bidentate chelating or bridging complexes with surface copper sites of the catalyst, i.e., the active sites. The catalytically undegradable carboxylates formed monodentate complexes with surface copper sites or just electrostatically adsorbed on the catalyst surface. The selectivity, relying on the structure of surface metal-carboxylate complex, should be considered in the design of catalytic ozonation process. © 2013 Elsevier B.V.

  8. Highly Carboxylated Cellulose Nanofibers via Succinic Anhydride Esterification of Wheat Fibers and Facile Mechanical Disintegration.

    Science.gov (United States)

    Sehaqui, H; Kulasinski, K; Pfenninger, N; Zimmermann, T; Tingaut, P

    2017-01-09

    We report herein the preparation of 4-6 nm wide carboxyl-functionalized cellulose nanofibers (CNF) via the esterification of wheat fibers with cyclic anhydrides (maleic, phtalic, and succinic) followed by an energy-efficient mechanical disintegration process. Remarkable results were achieved via succinic anhydride esterification that enabled CNF isolation by a single pass through the microfluidizer yielding a transparent and thick gel. These CNF carry the highest content of carboxyl groups ever reported for native cellulose nanofibers (3.8 mmol g -1 ). Compared to conventional carboxylated cellulose nanofibers prepared via Tempo-mediated oxidation of wheat fibers, the present esterified CNF display a higher molar-mass and a better thermal stability. Moreover, highly carboxylated CNF from succinic anhydride esterification were effectively integrated into paper filters for the removal of lead from aqueous solution and are potentially of interest as carrier of active molecules or as transparent films for packaging, biomedical or electronic applications.

  9. Comparative bioavailability studies of citric acid and malonic acid based aspirin effervescent tablets

    Directory of Open Access Journals (Sweden)

    Anju Gauniya

    2010-01-01

    Full Text Available Purpose: The present investigation is aimed at comparing the pharmacokinetic profile (Bioavailability of aspirin in tablet formulations, which were prepared by using different effervescent excipients such as citric acid and malonic acid. Materials and Methods: The relative bioavailability and pharmacokinetics of citric acid based aspirin effervescent tablet (Product A and malonic acid based aspirin effervescent tablet (Product B formulations were evaluated for an in-vitro dissolution study and in-vivo bioavailability study, in 10 normal healthy rabbits. The study utilized a randomized, crossover design with a one-week washout period between doses. Blood samples were collected at 0, 1, 2, 4, 6, 8, 12 and 24 hours following a 100 mg/kg dose. Plasma samples were assayed by High Performance Liquid Chromatography. T max , C max , AUC 0-24 , AUC 0- ∞, MRT, K a, and relative bioavailability were estimated using the traditional pharmacokinetic methods and were compared by using the paired t-test. Result: In the present study, Products A and B showed their T max , C max , AUC 0-24 , AUC 0- ∞, MRT, and K a values as 2.5 h, 2589 ± 54.79 ng/ml, 9623 ± 112.87 ng.h/ml, 9586 ± 126.22 ng.h/ml, 3.6 ± 0.10 h, and 0.3698 ± 0.003 h -1 for Product A and 3.0 h, 2054 ± 55.79 ng/ml, 9637 ± 132.87 ng.h/ml, 9870 ± 129.22 ng.h/ml, 4.76 ± 0.10 h, and 0.3812 ± 0.002 h -1 for Product B, respectively. Conclusion: The results of the paired t-test of pharmacokinetics data showed that there was no significant difference between Products A and B. From both the in vitro dissolution studies and in vivo bioavailability studies it was concluded that products A and B had similar bioavailability.

  10. [Effects of different neutralizing agents on succinate production by Actinobacillus succinogenes NJ113].

    Science.gov (United States)

    Yang, Zhuona; Jiang, Min; Li, Jian; Fang, Xiaojiang; Ye, Guizi; Bai, Xuefei; Zheng, Xiaoyu; Wei, Ping

    2010-11-01

    Different neutralizing agents were used as pH controller to investigate their effects on the growth and succinic acid production of Actinobacillus succinogenes NJ113. The fermentation results showed that Ca(OH)2, CaCO3 and NH4OH were not suitable for succinic acid production by A. succinogenes NJ113 because of their negative effects on cell growth. When Na-base was used, cells would flocculate and lump, and due to the sodium ion concentration reaching to a high level, OD660 dropped sharply after 12 h of fermentation. Mg-base was better because there was no significant inhibition by magnesium ion. Two combined neutralizing agents were used to maintain pH level, one with NaOH and Mg(OH)2 while the other with Na2CO3 and Mg(OH)2. The optimum ratios of the combined neutralizing agents were both 1:1 (g:g) when using 100 g/L glucose. When NaOH and Mg(OH)2 were chosen with the ratio of 1:1(g:g), 69.8 g/L of the succinic acid and 74.5% of the yield was obtained.

  11. Temporal variations in dimethylsulphoniopropionate and dimethyl sulphide in the Zuari estuary, Goa (India)

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; Patil, J.S.

    . F., & Wakeham, S. G. (1998). Temporal variability of dimethyl sulfide and dimethylsulfoniopropionate in the Sargasso Sea. DeepSeaRes.PartI, 45, 2085– 2104. DeSouza, M. P., & Yoch, D. C. (1996). Differential metabolism of dimethyl...) measurements and a procedure to predict sea surface DMS as a function of latitude, longitude, and month.GlobalBiogeochemicalCycles,13, 399–444. Kiene, R. P. (1990). Dimethyl sulfide production from dimethyl-sulfoniopropionate in coastal seawater samples...

  12. Determination of vitamin E acid succinate in biodegradable microspheres by reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Martínez Sancho, C; Herrero Vanrell, R; Negro, S

    2004-01-01

    A simple, rapid, and reproducible reversed-phase high-performance liquid chromatographic (HPLC) method is applied to the routine assay of vitamin E acid succinate in biodegradable microspheres. Vitamin E acid-succinate-containing poly-(D,L-lactic-co-glycolic acid) microspheres are prepared by the solvent evaporation method. The starting drug-polymer ratio is 1:10 (w/w) and the total amount of drug and polymer processed is always 440 mg. The content of vitamin E acid succinate in the microspheres is evaluated by HPLC. Chromatography is carried out isocratically at 25 degrees C +/- 0.5 degrees C on an Extrasil ODS-2 column with a mobile phase composed of methanol-water (97:3, v/v) (pH 5.6) at a flow rate of 2 mL/min and UV detection at 284 nm. Parameters such as linearity, limits of quantitation (LOQ) and detection (LOD), precision, accuracy, recovery, specificity, and ruggedness are studied as reported in the International Conference on Harmonization guidelines. The stability of vitamin E acid succinate is also studied with satisfactory results after 48 h at 25 degrees C. The method is selective and linear for drug concentrations in the range 15-210 micro g/mL. The LOQ and LOD are 15 and 3 micro g/mL, respectively. The results for accuracy studies are good. Values for coefficient of variation for intra- and interassay are 2.08% and 2.32%, respectively. The mean percentage of vitamin E acid succinate in the recovery studies is 99.52% +/- 0.81%. The mean loading efficiency for microspheres is 96.53% +/- 1.31%.

  13. Synthesis of Novel Homo-N-Nucleoside Analogs Composed of a Homo-1,4-Dioxane Sugar Analog and Substituted 1,3,5-Triazine Base Equivalents

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    2008-12-01

    Full Text Available Enantioselective syntheses from dimethyl tartrate of 1,3,5-triazine homo-N-nucleoside analogs, containing a 1,4-dioxane moiety replacing the sugar unit in natural nucleosides, were accomplished. The triazine heterocycle in the nucleoside analogs was further substituted with combinations of NH2, OH and Cl in the 2,4-triazine positions.

  14. Integrated production of cellulosic bioethanol and succinic acid from industrial hemp in a biorefinery concept.

    Science.gov (United States)

    Kuglarz, Mariusz; Alvarado-Morales, Merlin; Karakashev, Dimitar; Angelidaki, Irini

    2016-01-01

    The aim of this study was to develop integrated biofuel (cellulosic bioethanol) and biochemical (succinic acid) production from industrial hemp (Cannabis sativa L.) in a biorefinery concept. Two types of pretreatments were studied (dilute-acid and alkaline oxidative method). High cellulose recovery (>95%) as well as significant hemicelluloses solubilization (49-59%) after acid-based method and lignin solubilization (35-41%) after alkaline H2O2 method were registered. Alkaline pretreatment showed to be superior over the acid-based method with respect to the rate of enzymatic hydrolysis and ethanol productivity. With respect to succinic acid production, the highest productivity was obtained after liquid fraction fermentation originated from steam treatment with 1.5% of acid. The mass balance calculations clearly showed that 149kg of EtOH and 115kg of succinic acid can be obtained per 1ton of dry hemp. Results obtained in this study clearly document the potential of industrial hemp for a biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Enhancing succinic acid biosynthesis in Escherichia coli by engineering its global transcription factor, catabolite repressor/activator (Cra).

    Science.gov (United States)

    Zhu, Li-Wen; Xia, Shi-Tao; Wei, Li-Na; Li, Hong-Mei; Yuan, Zhan-Peng; Tang, Ya-Jie

    2016-11-04

    This study was initiated to improve E. coli succinate production by engineering the E. coli global transcription factor, Cra (catabolite repressor/activator). Random mutagenesis libraries were generated through error-prone PCR of cra. After re-screening and mutation site integration, the best mutant strain was Tang1541, which provided a final succinate concentration of 79.8 ± 3.1 g/L: i.e., 22.8% greater than that obtained using an empty vector control. The genes and enzymes involved in phosphoenolpyruvate (PEP) carboxylation and the glyoxylate pathway were activated, either directly or indirectly, through the mutation of Cra. The parameters for interaction of Cra and DNA indicated that the Cra mutant was bound to aceBAK, thereby activating the genes involved in glyoxylate pathway and further improving succinate production even in the presence of its effector fructose-1,6-bisphosphate (FBP). It suggested that some of the negative effect of FBP on Cra might have been counteracted through the enhanced binding affinity of the Cra mutant for FBP or the change of Cra structure. This work provides useful information about understanding the transcriptional regulation of succinate biosynthesis.

  16. Dimethyl Fumarate Inhibits the Nuclear Factor κB Pathway in Breast Cancer Cells by Covalent Modification of p65 Protein.

    Science.gov (United States)

    Kastrati, Irida; Siklos, Marton I; Calderon-Gierszal, Esther L; El-Shennawy, Lamiaa; Georgieva, Gergana; Thayer, Emily N; Thatcher, Gregory R J; Frasor, Jonna

    2016-02-12

    In breast tumors, activation of the nuclear factor κB (NFκB) pathway promotes survival, migration, invasion, angiogenesis, stem cell-like properties, and resistance to therapy--all phenotypes of aggressive disease where therapy options remain limited. Adding an anti-inflammatory/anti-NFκB agent to breast cancer treatment would be beneficial, but no such drug is approved as either a monotherapy or adjuvant therapy. To address this need, we examined whether dimethyl fumarate (DMF), an anti-inflammatory drug already in clinical use for multiple sclerosis, can inhibit the NFκB pathway. We found that DMF effectively blocks NFκB activity in multiple breast cancer cell lines and abrogates NFκB-dependent mammosphere formation, indicating that DMF has anti-cancer stem cell properties. In addition, DMF inhibits cell proliferation and significantly impairs xenograft tumor growth. Mechanistically, DMF prevents p65 nuclear translocation and attenuates its DNA binding activity but has no effect on upstream proteins in the NFκB pathway. Dimethyl succinate, the inactive analog of DMF that lacks the electrophilic double bond of fumarate, is unable to inhibit NFκB activity. Also, the cell-permeable thiol N-acetyl l-cysteine, reverses DMF inhibition of the NFκB pathway, supporting the notion that the electrophile, DMF, acts via covalent modification. To determine whether DMF interacts directly with p65, we synthesized and used a novel chemical probe of DMF by incorporating an alkyne functionality and found that DMF covalently modifies p65, with cysteine 38 being essential for the activity of DMF. These results establish DMF as an NFκB inhibitor with anti-tumor activity that may add therapeutic value in the treatment of aggressive breast cancers. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. A highly sensitive and selective dimethyl ether sensor based on cataluminescence.

    Science.gov (United States)

    Zhang, Runkun; Cao, Xiaoan; Liu, Yonghui; Peng, Yan

    2010-07-15

    A sensor for detecting dimethyl ether was designed based on the cataluminescence phenomenon when dimethyl ether vapors were passing through the surface of the ceramic heater. The proposed sensor showed high sensitivity and selectivity to dimethyl ether at an optimal temperature of 279 degrees C. Quantitative analysis were performed at a wavelength of 425 nm, the flow rate of carrier air is around 300 mL/min. The linear range of the cataluminescence intensity versus concentration of dimethyl ether is 100-6.0x10(3) ppm with a detection limit of 80 ppm. The sensor response time is 2.5 s. Under the optimized conditions, none or only very low levels of interference were observed while the foreign substances such as benzene, formaldehyde, ammonia, methanol, ethanol, acetaldehyde, acetic acid, acrolein, isopropyl ether, ethyl acetate, glycol ether and 2-methoxyethanol were passing through the sensor. Since the sensor does not need to prepare and fix up the granular catalyst, the simple technology reduces cost, improves stability and extends life span. The method can be applied to facilitate detection of dimethyl ether in the air. The possible mechanism of cataluminescence from the oxidation of dimethyl ether on the surface of ceramic heater was discussed based on the reaction products. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Utilization of CO2 fixating bacterium Actinobacillus succinogenes 130Z for simultaneous biogas upgrading and bio-succinic acid production

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi; Alvarado-Morales, Merlin; Angelidaki, Irini

    2014-01-01

    Biogas is an attractive renewable energy carrier. However, it contains CO2 which limits certain applications of biogas. Here we report a novel approach for removing CO2 from biogas and capturing it as a biochemical through a biological process. This approach entails converting CO2 into bio...... and titre, CO2 consumption rate and CH4 purity. When using biogas as the only CO2 source at 140 kPa, the CO2 consumption rate corresponded to 2.59 L CO2 L-1 d-1 with a final succinic acid titre of 14.4 g L-1. Under this pressure condition the highest succinic acid yield and biogas quality reached......-succinic acid using the bacterial strain Actinobacillus succinogenes 130Z, and simultaneously producing high purity CH4 (>95%). Results showed that when pressure during fermentation was increased from 101.325 to 140 kPa, higher CO2 solubility was achieved, thereby positively affecting final succinic acid yield...

  19. Thermochemical study of 2,5-dimethyl-3-furancarboxylic acid, 4,5-dimethyl-2-furaldehyde, and 3-acetyl-2,5-dimethylfuran

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Amaral, Luisa M.P.F.

    2011-01-01

    The standard (p o = 0.1 MPa) molar enthalpies of formation, in the gaseous state, at T = 298.15 K, for 2,5-dimethyl-3-furancarboxylic acid, 3-acetyl-2,5-dimethylfuran, and 4,5-dimethyl-2-furaldehyde were derived from the values of the standard molar enthalpies of formation, in the condensed phase, and the standard molar enthalpies of phase transition from the condensed to the gaseous state. The values of the standard molar enthalpies of formation of the compounds in the condensed phases were calculated from the measurements of the standard massic energies of combustion obtained by static bomb combustion calorimetry. The enthalpies of vaporization/sublimation were measured by Calvet high temperature microcalorimetry. For 2,5-dimethyl-3-furancarboxylic acid the standard enthalpy of sublimation was also calculated, by the application of the Clausius-Clapeyron equation, to the temperature dependence of the vapor pressures measured by the Knudsen effusion technique. (table)

  20. Preparation And Physicochemical Properties of Octenyl Succinic Anhydride (OSA) Modified Sago Starch

    International Nuclear Information System (INIS)

    Nur Farhana Zainal Abiddin; Anida Yusoff; Noorlaila Ahmad

    2016-01-01

    Starch from sago (Metroxylon sagu) was esterified with octenyl succinic anhydride (OSA) in order to regulate its shortcoming by adding amphiphilic properties. The objective of this work is to determine the physicochemical properties of native sago and OSA sago starches. The OSA sago starch was produced according to the optimum condition generated via response surface methodology (RSM) with 5.00 % OSA at pH 7.20 and a reaction time of 9.65 hours. The esterified sago starch gives a degree of substitution (DS) value of 0.012. The physicochemical properties of OSA sago starch was determined by measuring the amylose content, laser diffraction particle size analyzer, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The amylose content for OSA sago starch was found to be reduced after esterification reaction. The particle size of OSA sago starch was found to increase significantly (p<0.05) compared to their native starches. Scanning electron microscopy (SEM) revealed that OSA starch developed slightly rough surface and their edges lost some definition. FT-IR spectroscopy shows that there was appearance of new absorption correspond to ester carbonyl group (1717 cm -1 ) and carboxylate RCOO- (1569 cm -1 ). This study showed that the physicochemical properties of modified starches were influenced not only by DS but also on the botanical origin of the starches. (author)

  1. Study on the synthesis of dimethyl 1,4-cyclohexanedicarboxylate by catalytic hydrogenation of dimethyl terephthalate

    Directory of Open Access Journals (Sweden)

    LI Yuanhua

    2016-12-01

    Full Text Available In the field of polymer industry,1,4-cyclohexanedimethanol (CHDM occupies an important position especially for the synthesis of highly valued polyester products.In industry,CHDM is prepared from dimethyl terephthalate (DMT through a two-step hydrogenation process Palladium supported on magnesium oxide (Pd/MgO was prepared by animpregnation method and was characterized by x-ray diffraction (XRD,transmission electron microscope (TEM and scan electron microscope (SEM.During the hydrogenation of DMT to synthesize dimethyl 1,4-cyclohexanedicarboxylate (DMCD,the as-prepared Pd/MgO was used as the catalyst with methyl acetate as the solvent.Under optimized reaction conditions (reaction temperature:180 ℃,reaction pressure:4.5 MPa,the conversion of DMT was 100% and the selectivity of DMCD was 99%.Such a catalyst shows a good potential in industrial applications.

  2. Receptor structure-based discovery of non-metabolite agonists for the succinate receptor GPR91

    DEFF Research Database (Denmark)

    Trauelsen, Mette; Rexen Ulven, Elisabeth; Hjorth, Siv A

    2017-01-01

    therefore binds in a very different mode than generally believed. Importantly, an empty side-pocket is identified next to the succinate binding site. All this information formed the basis for a substructure-based search query, which, combined with molecular docking, was used in virtual screening of the ZINC...... database to pick two serial mini-libraries of a total of only 245 compounds from which sub-micromolar, selective GPR91 agonists of unique structures were identified. The best compounds were backbone-modified succinate analogs in which an amide-linked hydrophobic moiety docked into the side-pocket next...

  3. Hydrogen/deuterium substitution methods: understanding water structure in solution

    International Nuclear Information System (INIS)

    Soper, A.K.

    1993-01-01

    The hydrogen/deuterium substitution method has been used for different applications, such as the short range order between water molecules in a number of different environments (aqueous solutions of organic molecules), or to study the partial structure factors of water at high pressure and temperature. The absolute accuracy that can be obtained remains uncertain, but important qualitative information can be obtained on the local organization of water in aqueous solution. Some recent results with pure water, methanol and dimethyl sulphoxide (DMSO) solutions are presented. It is shown that the short range water structure is not greatly affected by most solutes except at high concentrations and when the solute species has its own distinctive interaction with water (such as a dissolved small ion). 3 figs., 14 refs

  4. [State of mitochondrial respiration and calcium capacity in livers of rats with different resistance to hypoxia after injections of L-arginine].

    Science.gov (United States)

    Kurhaliuk, N M

    2001-01-01

    In experiments on rats with different resistance to hypoxia are investigated processes of mitochondrial respiration, oxidative phosphorylation and calcium capacity in liver under precursor nitric oxide L-arginine (600 mg/kg) and blockator nitric oxide synthase L-NNA (35 mg/kg) injections. We are used next substrates of oxidation: 0.35 mM succinate, 1 mM alpha-ketoglutarate, 1 mM alpha-ketoglutarate and 2 mM malonic acid. Increasing of ADP-stimulation respiration states under exogenous L-arginine injection, decreasing efficacy of respiration processes (respiration control on Chance and ADP/O) under such substrates oxidation, testify to oxide energy support decreasing and reversing nitric oxide inhibit in such conditions. This will be used as mechanism cell regulation succinate dehydrogenase activity. It has shown that L-arginine injection increase calcium mitochondrial capacity low resistance to hypoxia rats using substrates of oxidation succinate and alpha-ketoglutarate to control meanings of high resistance rats. Effects of nitric oxide precursor influence on this processes limit NO-synthase inhibitor L-NNA.

  5. Nb-Based Zeolites: Efficient bi-Functional Catalysts for the One-Pot Synthesis of Succinic Acid from Glucose

    Directory of Open Access Journals (Sweden)

    Magdi El Fergani

    2017-12-01

    Full Text Available The one-pot production of succinic acid from glucose was investigated in pure hot water as solvent using Nb (0.02 and 0.05 moles%-Beta zeolites obtained by a post-synthesis methodology. Structurally, they are comprised of residual framework Al-acid sites, extra-framework isolated Nb (V and Nb2O5 pore-encapsulated clusters. The Nb-modified Beta-zeolites acted as bi-functional catalysts in which glucose is dehydrated to levulinic acid (LA which, further, suffers an oxidation process to succinic acid (SA. After the optimization of the reaction conditions, that is, at 180 °C, 18 bar O2, and 12 h reaction time, the oxidation of glucose occurred with a selectivity to succinic acid as high as 84% for a total conversion.

  6. Quantification of N-acetylcysteamine activated methylmalonate incorporation into polyketide biosynthesis

    Directory of Open Access Journals (Sweden)

    Stephan Klopries

    2013-04-01

    Full Text Available Polyketides are biosynthesized through consecutive decarboxylative Claisen condensations between a carboxylic acid and differently substituted malonic acid thioesters, both tethered to the giant polyketide synthase enzymes. Individual malonic acid derivatives are typically required to be activated as coenzyme A-thioesters prior to their enzyme-catalyzed transfer onto the polyketide synthase. Control over the selection of malonic acid building blocks promises great potential for the experimental alteration of polyketide structure and bioactivity. One requirement for this endeavor is the supplementation of the bacterial polyketide fermentation system with tailored synthetic thioester-activated malonates. The membrane permeable N-acetylcysteamine has been proposed as a coenzyme A-mimic for this purpose. Here, the incorporation efficiency into different polyketides of N-acetylcysteamine activated methylmalonate is studied and quantified, showing a surprisingly high and transferable activity of these polyketide synthase substrate analogues in vivo.

  7. Out of plane distortions of the heme b of Escherichia coli succinate dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Quang M Tran

    Full Text Available The role of the heme b in Escherichia coli succinate dehydrogenase is highly ambiguous and its role in catalysis is questionable. To examine whether heme reduction is an essential step of the catalytic mechanism, we generated a series of site-directed mutations around the heme binding pocket, creating a library of variants with a stepwise decrease in the midpoint potential of the heme from the wild-type value of +20 mV down to -80 mV. This difference in midpoint potential is enough to alter the reactivity of the heme towards succinate and thus its redox state under turnover conditions. Our results show both the steady state succinate oxidase and fumarate reductase catalytic activity of the enzyme are not a function of the redox potential of the heme. As well, lower heme potential did not cause an increase in the rate of superoxide production both in vitro and in vivo. The electron paramagnetic resonance (EPR spectrum of the heme in the wild-type enzyme is a combination of two distinct signals. We link EPR spectra to structure, showing that one of the signals likely arises from an out-of-plane distortion of the heme, a saddled conformation, while the second signal originates from a more planar orientation of the porphyrin ring.

  8. Malonic acid concentration as a control parameter in the kinetic analysis of the Belousov-Zhabotinsky reaction under batch conditions.

    Science.gov (United States)

    Blagojević, Slavica M; Anić, Slobodan R; Cupić, Zeljko D; Pejić, Natasa D; Kolar-Anić, Ljiljana Z

    2008-11-28

    The influence of the initial malonic acid concentration [MA]0 (8.00 x 10(-3) sulfuric acid (1.00 mol dm(-3)) and cerium sulfate (2.50 x 10(-3) mol dm(-3)) on the dynamics and the kinetics of the Belousov-Zhabotinsky (BZ) reactions was examined under batch conditions at 30.0 degrees C. The kinetics of the BZ reaction was analyzed by the earlier proposed method convenient for the examinations of the oscillatory reactions. In the defined region of parameters where oscillograms with only large-amplitude relaxation oscillations appeared, the pseudo-first order of the overall malonic acid decomposition with a corresponding rate constant of 2.14 x 10(-2) min(-1) was established. The numerical results on the dynamics and kinetics of the BZ reaction, carried out by the known skeleton model including the Br2O species, were in good agreement with the experimental ones. The already found saddle node infinite period (SNIPER) bifurcation point in transition from a stable quasi-steady state to periodic orbits and vice versa is confirmed by both experimental and numerical investigations of the system under consideration. Namely, the large-amplitude relaxation oscillations with increasing periods between oscillations in approaching the bifurcation points at the beginning and the end of the oscillatory domain, together with excitability of the stable quasi-steady states in their vicinity are obtained.

  9. Direct Succinic Acid Production from Minimally Pretreated Biomass Using Sequential Solid-State and Slurry Fermentation with Mixed Fungal Cultures

    Directory of Open Access Journals (Sweden)

    Jerico Alcantara

    2017-06-01

    Full Text Available Conventional bio-based succinic acid production involves anaerobic bacterial fermentation of pure sugars. This study explored a new route for directly producing succinic acid from minimally-pretreated lignocellulosic biomass via a consolidated bioprocessing technology employing a mixed lignocellulolytic and acidogenic fungal co-culture. The process involved a solid-state pre-fermentation stage followed by a two-phase slurry fermentation stage. During the solid-state pre-fermentation stage, Aspergillus niger and Trichoderma reesei were co-cultured in a nitrogen-rich substrate (e.g., soybean hull to induce cellulolytic enzyme activity. The ligninolytic fungus Phanerochaete chrysosporium was grown separately on carbon-rich birch wood chips to induce ligninolytic enzymes, rendering the biomass more susceptible to cellulase attack. The solid-state pre-cultures were then combined in a slurry fermentation culture to achieve simultaneous enzymatic cellulolysis and succinic acid production. This approach generated succinic acid at maximum titers of 32.43 g/L after 72 h of batch slurry fermentation (~10 g/L production, and 61.12 g/L after 36 h of addition of fresh birch wood chips at the onset of the slurry fermentation stage (~26 g/L production. Based on this result, this approach is a promising alternative to current bacterial succinic acid production due to its minimal substrate pretreatment requirements, which could reduce production costs.

  10. Bio-oil based biorefinery strategy for the production of succinic acid

    DEFF Research Database (Denmark)

    Wang, Caixia; Thygesen, Anders; Liu, Yilan

    2013-01-01

    Background: Succinic acid is one of the key platform chemicals which can be produced via biotechnology process instead of petrochemical process. Biomass derived bio-oil have been investigated intensively as an alternative of diesel and gasoline fuels. Bio-oil could be fractionized into organic...

  11. Viscoelastic and electrical properties of carbon nanotubes filled poly(butylene succinate)

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2014-03-01

    Full Text Available The carbon nanotubes (CNTs)-containing composites of poly(butylene succinate) (PBS) were prepared by melt-blending in a batch mixer with three concentrations by weight of CNTs: 1, 2 and 3 %. State of dispersion-distribution of the CNTs in the PBS...

  12. Effect of vitamin E succinate on inflammatory cytokines induced by high-intensity interval training.

    Science.gov (United States)

    Sarir, Hadi; Emdadifard, Ghodsieh; Farhangfar, Homayoun; TaheriChadorneshin, Hossein

    2015-12-01

    The anti-inflammatory effect of vitamin E under moderate exercises has been evaluated. However, the effect of vitamin E succinate, which has more potent anti-inflammatory effect than other isomers of vitamin E has not been evaluated. Therefore, the aim of the present study was to evaluate the effects of vitamin E succinate on tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) production induced by high-intensity interval training (HIIT). In the present study, 24 rats were randomly divided into control (C), supplementation (S), HIIT, and HIIT + supplementation (HIIT+S) groups. HIIT training protocol on a treadmill (at a speed of 40-54 m/min) and vitamin E succinate supplementation (60 mg/kg/day) was conducted for 6 weeks. Serum IL-6 in the HIIT group significantly increased compared with the C group (350.42 ± 123.31 pg/mL vs 158.60 ± 41.96 pg/mL; P = 0.002). Also, serum TNF-α concentrations significantly enhanced (718.15 ± 133.42 pg/mL vs 350.87 ± 64.93 pg/mL; P = 0.001) in the HIIT group compared with the C group. Treatment of the training group with vitamin E numerically reduced IL-6 and TNF-α when compared with the HIIT group (217.31 ± 29.21 and 510.23 ± 217.88, respectively, P > 0.05). However, no significant changes were observed in serum TNF-α (P = 0.31) and IL-6 (P = 0.52) concentrations in the HIIT + S group compared with the C group. HIIT-induced IL-6 and TNF-α decreased by administration of Vitamin E succinate.

  13. Production of succinic acid from sugarcane molasses supplemented with a mixture of corn steep liquor powder and peanut meal as nitrogen sources by Actinobacillus succinogenes.

    Science.gov (United States)

    Shen, N; Qin, Y; Wang, Q; Liao, S; Zhu, J; Zhu, Q; Mi, H; Adhikari, B; Wei, Y; Huang, R

    2015-06-01

    The potential of using corn steep liquor powder (CSLP), peanut meal (PM), soybean meal (SM), cotton meal (CM) and urea as the substitute of yeast extract (YE) as the nitrogen source was investigated for producing succinic acid (SA). Actinobacillus succinogenes GXAS137 was used as the fermenting bacterium and sugarcane molasses was used as the main substrate. None of these materials were able to produce SA as high as YE did. The CSLP could still be considered as a feasible and inexpensive alternate for YE as the yield of SA produced using CSLP was second only to the yield of SA obtained by YE. The use of CSLP-PM mixed formulation (CSLP to PM ratio = 2·6) as nitrogen source produced SA up to 59·2 g l(-1) with a productivity of 1·2 g l(-1) h(-1). A batch fermentation using a stirred bioreactor produced up to 60·7 g l(-1) of SA at the same formulation. Fed-batch fermentation that minimized the substrate inhibition produced 64·7 g l(-1) SA. These results suggest that sugarcane molasses supplemented with a mixture of CSLP and PM as the nitrogen source could be used to produce SA more economically using A. succinogenes. Significance and impact of the study: Succinic acid (SA) is commonly used as a platform chemical to produce a number of high value derivatives. Yeast extract (YE) is used as a nitrogen source to produce SA. The high cost of YE is currently the limiting factor for industrial production of SA. This study reports the use of a mixture of corn steep liquor powder (CSLP) and peanut meal (PM) as an inexpensive nitrogen source to substitute YE. The results showed that this CSLP-PM mixed formulation can be used as an effective and economic nitrogen source for the production of SA. © 2015 The Society for Applied Microbiology.

  14. Hepatoprotective Activity of a Complex Compound of 5-Hydroxy-6-Methyluracil and Succinic Acid in Experimental Peritonitis

    Directory of Open Access Journals (Sweden)

    D. A. Yenikeyev

    2008-01-01

    Full Text Available Objective: to evaluate the hepatoprotective efficacy of a complex compound of 5-hydroxy-6-methyluracil and succinic acid in experimental peritonitis. Materials and methods. Experiments were carried out on 48 male albino rats in which peritonitis was simulated via intraperitoneal administration of 7% fecal suspension in a dose of 0.6 ml per 100 g bodyweight. The rate of free radical oxidation processes, the activity of antioxidative protection, the degree of endogenous intoxication and cytolytic syndrome, and the effect of the test compound on these parameters were estimated in the experiment. Results. With the development of an abdominal inflammatory process, there were increases in rates of endogenous intoxication and free radical oxidation (FRO, a change in the activity of antioxidative protection enzymes, and a reduction in the levels of ceruloplasmin and sulfahydryl groups. The complex compound, that comprised 5-hydroxy-6-methyluracil and succinic acid used as monotherapy, reduced the degree of endogenous intoxication, FRO, and lipid peroxidation-antioxidative defense system imbalance. Conclusion. The experimental data suggest that the use of the complex compound containing succinic acid and 5-hydroxy-6-methy-luracil is pathogenetically warranted. Key words: peritonitis, lipid peroxidation, antioxidants, succinic acid, pyrim-idine derivatives.

  15. Influence of the course prescription of sodium succinate on functional state and general physical working ability of footballers organism during the training sessions

    Directory of Open Access Journals (Sweden)

    Олексій Володимирович Чернєв

    2015-09-01

    Full Text Available Pharmacological purpose of metabotropic preparations including burshtin acid and its derivative succinate sodium copes with the number of tasks the main of which is an activation of alternative ways of energoproduction at the work of submaximal and maximal force and preliminary training of the separate links of metabolism.The task of research is to ascertain changes that take place in functional state of sportsmen during long physical loadings and optimization of the work of cardiovascular system (CVS and prophylaxis of psychical strains with the help of succinate sodium.Methods and organization of research. There were examined 84 sportsmen to ascertain changes that take place in the functional state of sportsmen during the long physical loadings and optimization of the work of CVS with the help of succinate sodium. Examinations took place during the training sessions (TS in January, February and July 2012-2013 years.Results of research and its discussion. There was studied an efficiency of the course use of succinate sodium in footballers 100 mg 3 times a day during 14 days. Energetic supply of processes of intracellular homeostasis in erythrocytes realizes by means of ATP that is created in the process of glycolysis. According to the results of research after course prescription of succinate sodium in sportsmen the content of ATP in erythrocytes increased and an amount of ADP and AMP decreased. An improvement of general metabolic situation under an influence of succinate sodium was proved by the decrease of products of reactions of peroxidation in blood plasma of footballers.These results indicated an essential antiacidotic effect of the course use of succinate sodium by footballers after loading in anaerobic and glycolytic zone of intensity. At the same time there was ascertain in our research that the use of succinate sodium had a positive effect on the dynamics of lactate content during the processes of renewal after training in aerobic

  16. Succinate-based preparation alleviates manifestations of the climacteric syndrome in women.

    Science.gov (United States)

    Peskov, A B; Maevskii, E I; Uchitel', M L; Sakharova, N Yu; Vize-Khripunova, M A

    2005-09-01

    Clinical placebo-controlled study of Enerlit-Clima (bioactive succinate-based food additive) a showed positive effect of the preparation on general clinical and psychoemotional manifestations of the climacteric syndrome. A trend to an increase in estradiol level in early pathological climacteric and normalization of the endometrial status were observed.

  17. Effect of atmospheric organic complexation on iron-bearing dust solubility

    Directory of Open Access Journals (Sweden)

    R. Paris

    2013-05-01

    Full Text Available Recent studies reported that the effect of organic complexation may be a potentially important process to be considered by models estimating atmospheric iron flux to the ocean. In this study, we investigated this process effect by a series of dissolution experiments on iron-bearing dust in the presence or the absence of various organic compounds (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of humic like substances, HULIS typically found in atmospheric waters. Only 4 of tested organic ligands (oxalate, malonate, tartrate and humic acid caused an enhancement of iron solubility which was associated with an increase of dissolved Fe(II concentrations. For all of these organic ligands, a positive linear dependence of iron solubility to organic concentrations was observed and showed that the extent of organic complexation on iron solubility decreased in the following order: oxalate >malonate = tartrate > humic acid. This was attributed to the ability of electron donors of organic ligands and implies a reductive ligand-promoted dissolution. This study confirms that among the known atmospheric organic binding ligands of Fe, oxalate is the most effective ligand promoting dust iron solubility and showed, for the first time, the potential effect of HULIS on iron dissolution under atmospheric conditions.

  18. Effect of vitamin E succinate on inflammatory cytokines induced by high-intensity interval training

    Directory of Open Access Journals (Sweden)

    Hadi Sarir

    2015-01-01

    Full Text Available Aim and Scope: The anti-inflammatory effect of vitamin E under moderate exercises has been evaluated. However, the effect of vitamin E succinate, which has more potent anti-inflammatory effect than other isomers of vitamin E has not been evaluated. Therefore, the aim of the present study was to evaluate the effects of vitamin E succinate on tumor necrosis factor alpha (TNF-a and interleukin-6 (IL-6 production induced by high-intensity interval training (HIIT. Materials and Methods: In the present study, 24 rats were randomly divided into control (C, supplementation (S, HIIT, and HIIT + supplementation (HIIT+S groups. HIIT training protocol on a treadmill (at a speed of 40-54 m/min and vitamin E succinate supplementation (60 mg/kg/day was conducted for 6 weeks. Results: Serum IL-6 in the HIIT group significantly increased compared with the C group (350.42 ± 123.31 pg/mL vs 158.60 ± 41.96 pg/mL; P = 0.002. Also, serum TNF-a concentrations significantly enhanced (718.15 ± 133.42 pg/mL vs 350.87 ± 64.93 pg/mL; P = 0.001 in the HIIT group compared with the C group. Treatment of the training group with vitamin E numerically reduced IL-6 and TNF-a when compared with the HIIT group (217.31 ± 29.21 and 510.23 ± 217.88, respectively, P > 0.05. However, no significant changes were observed in serum TNF-a (P = 0.31 and IL-6 (P = 0.52 concentrations in the HIIT + S group compared with the C group. Conclusion: HIIT-induced IL-6 and TNF-α decreased by administration of Vitamin E succinate.

  19. Enhanced Bioactivity of α-Tocopheryl Succinate Based Block Copolymer Nanoparticles by Reduced Hydrophobicity.

    Science.gov (United States)

    Palao-Suay, Raquel; Aguilar, María Rosa; Parra-Ruiz, Francisco J; Maji, Samarendra; Hoogenboom, Richard; Rohner, Nathan A; Thomas, Susan N; Román, Julio San

    2016-12-01

    Well-structured amphiphilic copolymers are necessary to obtain self-assembled nanoparticles (NPs) based on synthetic polymers. Highly homogeneous and monodispersed macromolecules obtained by controlled polymerization have successfully been used for this purpose. However, disaggregation of the organized macromolecules is desired when a bioactive element, such as α-tocopheryl succinate, is introduced in self-assembled NPs and this element must be exposed or released to exert its action. The aim of this work is to demonstrate that the bioactivity of synthetic NPs based on defined reversible addition-fragmentation chain transfer polymerization copolymers can be enhanced by the introduction of hydrophilic comonomers in the hydrophobic segment. The amphiphilic terpolymers are based on poly(ethylene glycol) (PEG) as hydrophilic block, and a hydrophobic block based on a methacrylic derivative of α-tocopheryl succinate (MTOS) and small amounts of 2-hydroxyethyl methacrylate (HEMA) (PEG-b-poly(MTOS-co-HEMA)). The introduction of HEMA reduces hydrophobicity and introduces "disorder" both in the homogeneous blocks and the compact core of the corresponding NPs. These NPs are able to encapsulate additional α-tocopheryl succinate (α-TOS) with high efficiency and their biological activity is much higher than that described for the unmodified copolymers, proposedly due to more efficient degradation and release of α-TOS, demonstrating the importance of the hydrophilic-hydrophobic balance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Enthalpies of potassium iodide dissolution in dimethyl acetamide mixtures with water

    International Nuclear Information System (INIS)

    Privalova, N.M.; Gritsenko, S.I.; Vorob'ev, A.F.

    1986-01-01

    Enthalpies of potassium iodide dissolution in mixed dimethyl acetamide - water solvent at 298.15 K in the whole range of dimethyl acetamide compositions are measured by the calorimetric method. From the plots of KI dissolution enthalpy dependence and dependence of experimental ΔH p∞ 0 value deviations from calculational ones on solvent composition, as well as from the results of calculation of solvate shell composition of potassium iodide ions in the mixed solvent, it is obvious that in the region of 0-15 mol% concentrations of dimethyl acetamide insufficient enrichment of solvate ion shells by dimethyl acetamide (DMAA) occurs, in the region of 15-40 mol% DMAA compositions enrichment of solvate shells of ions by water occurs, in the region of 40-100 mol% DMAA enrichment of solvate ion shells by the organic component in comparison with mixture compostion occurs. Maximum enrichment of solvate ion shells by mixture components in three above mentioned regions of the mixed solvent occurs at 10, 30 and 80 mol% DMAA concentrations

  1. Hanford waste vitrification plant hydrogen generation study: Preliminary evaluation of alternatives to formic acid

    International Nuclear Information System (INIS)

    King, R.B.; Bhattacharyya, N.K.; Kumar, V.

    1996-02-01

    Oxalic, glyoxylic, glycolic, malonic, pyruvic, lactic, levulinic, and citric acids as well as glycine have been evaluated as possible substitutes for formic acid in the preparation of feed for the Hanford waste vitrification plant using a non-radioactive feed stimulant UGA-12M1 containing substantial amounts of aluminum and iron oxides as well as nitrate and nitrite at 90C in the presence of hydrated rhodium trichloride. Unlike formic acid none of these carboxylic acids liberate hydrogen under these conditions and only malonic and citric acids form ammonia. Glyoxylic, glycolic, malonic, pyruvic, lactic, levulinic, and citric acids all appear to have significant reducing properties under the reaction conditions of interest as indicated by the observation of appreciable amounts of N 2 O as a reduction product of,nitrite or, less likely, nitrate at 90C. Glyoxylic, pyruvic, and malonic acids all appear to be unstable towards decarboxylation at 90C in the presence of Al(OH) 3 . Among the carboxylic acids investigated in this study the α-hydroxycarboxylic acids glycolic and lactic acids appear to be the most interesting potential substitutes for formic acid in the feed preparation for the vitrification plant because of their failure to produce hydrogen or ammonia or to undergo decarboxylation under the reaction conditions although they exhibit some reducing properties in feed stimulant experiments

  2. Reaction of dimethyl hydrogen phosphite with acecyclone

    International Nuclear Information System (INIS)

    Arbuzov, B.A.; Fuzhenkova, A.V.; Tyryshkin, N.I.

    1987-01-01

    In the presence of bases acecyclone reacts with dimethyl hydrogen phosphite with the formation of gamma-keto phosphonates with conjugated and unconjugated structures, and also an enol phosphate, a product containing a bond between oxygen of the cyclone and phosphorus. In the absence of bases, as well as the beta-keto phosphonate, gamma-keto phosphonates of cis and trans structure are formed; they are products of the 1,4 addition of dimethyl hydrogen phosphite to the conjugated fragment C=C-C=O of the cyclone. The compositions of the reaction mixture were determined by IR and NMR spectroscopy and TLC. Full-scale analysis of chemical shifts and spin-spin coupling constants was performed

  3. Inhibition of mitochondrial glycerol-3-phosphate dehydrogenase by alpha-tocopheryl succinate

    Czech Academy of Sciences Publication Activity Database

    Rauchová, Hana; Vokurková, Martina; Drahota, Zdeněk

    2014-01-01

    Roč. 53, AUG (2014), s. 409-413 ISSN 1357-2725 R&D Projects: GA ČR(CZ) GAP304/12/0259 Institutional support: RVO:67985823 Keywords : brown adipose tissue mitochondria * oxygen consumption * glycerol-3-phosphate * succinate * reactive oxygen species Subject RIV: ED - Physiology Impact factor: 4.046, year: 2014

  4. Voltametric study of formic and dihydroxy malonic acids on platinum for the definition of a process for the electrolytic destruction of carboxylic acids in radioactive aqueous effluents; Etude voltamperometrique des acides formiques et dihydroxymalonique sur platine en vue de la definition d`un procede de destruction electrolytique d`acides carboxyliques d`effluents aqueux radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Le Naour, C.

    1994-05-01

    To limit the amount of nuclear glasses generated by the treatment of the degraded solvent from the PUREX process for reprocessing of nuclear fuels, by solutions of sodium carbonate and caustic soda, it is planned to exploit the complexing power of certain carboxylic acids to return the metallic cations to the aqueous phase. The concept of this new treatment of the solvent by `substitution` reagents demands a process for the decomposition of these reagents, especially to CO{sub 2}. The investigation of the electrochemical behaviour, on platinum, of a substance selected as a model for understanding the interfacial mechanisms (HCOOH), and of dihydroxy malonic acid, revealed two distinct electro-poisoning processes: one is due to the adsorption of CO on the surface sites of platinum, and the second to the formation of a passivating layer of P{dagger}O. The application of 20 kHz ultrasonic flux in the neighbourhood of the platinum / aqueous formic acid solution interface also appears to cause a change in the superficial structure of the electrode used, in a direction that favours the decomposition of this compound. To overcome problems of poisoning of the platinum surface, aqueous solutions of formic, dihydroxy malonic and oxalic acids were electrolysed, in a cell without diaphragm, by applying voltage and current ranges, at levels adapted to each of the species. It is necessary to bring the working electrode to a higher potential than the oxidation potential for formic acid, and to a lower potential for dihydroxy malonic and oxalic acids. The frequent modifications of the electrode potentials helped to achieve quantitative destruction of these species, to CO{sub 2} (and to water) with an electrochemical efficiency approaching 100 %. This wet oxidation process also offers the advantage of not raising the energy potential of the effluents to be treated, because it takes place in mild conditions (ambient temperature and pressure). (author). 131 refs., 90 figs., 48 tabs.

  5. Succinate production positively correlates with the affinity of the global transcription factor Cra for its effector FBP in Escherichia coli.

    Science.gov (United States)

    Wei, Li-Na; Zhu, Li-Wen; Tang, Ya-Jie

    2016-01-01

    Effector binding is important for transcription factors, affecting both the pattern and function of transcriptional regulation to alter cell phenotype. Our previous work suggested that the affinity of the global transcription factor catabolite repressor/activator (Cra) for its effector fructose-1,6-bisphosphate (FBP) may contribute to succinate biosynthesis. To support this hypothesis, single-point and three-point mutations were proposed through the semi-rational design of Cra to improve its affinity for FBP. For the first time, a positive correlation between succinate production and the affinity of Cra for FBP was revealed in Escherichia coli . Using the best-fit regression function, a cubic equation was used to examine and describe the relationship between succinate production and the affinity of Cra for FBP, demonstrating a significant positive correlation between the two factors (coefficient of determination R 2  = 0.894, P  = 0.000 Cra and DNA showed that Cra bound to the promoter regions of pck and aceB to activate the corresponding genes. Normally, Cra-regulated operons under positive control are deactivated in the presence of FBP. Therefore, theoretically, the enhanced affinity of Cra for FBP will inhibit the activation of pck and aceB . However, the activation of genes involved in CO 2 fixation and the glyoxylate pathway was further improved by the Cra mutant, ultimately contributing to succinate biosynthesis. Enhanced binding of Cra to FBP or active site mutations may eliminate the repressive effect caused by FBP, thus leading to increased activation of genes associated with succinate biosynthesis in the Cra mutant. This work demonstrates an important transcriptional regulation strategy in the metabolic engineering of succinate production and provides useful information for better understanding of the regulatory mechanisms of transcription factors.

  6. Thermodynamic properties of actinide complexes

    International Nuclear Information System (INIS)

    Bismondo, A.; Cassol, A.; Di Bernardo, P.; Magon, L.; Tomat, G.; Consiglio Nazionale delle Ricerche, Padua

    1981-01-01

    In a previous paper the stability constants and the enthalpies of formation of uranyl(VI)-malonate complexes in 1 M Na(ClO 4 ) and at 25.0 0 C, have been reported. In order to assess the influence of the number of methylenic groups in the ligand chain on the stability constants of the formed complexes and on their ΔH and ΔS values, a series of potentiometric and calorimetric investigations were carried out on the uranyl(VI)-succinate system. The results are given and discussed. (author)

  7. Gamma irradiation of isocitric and citric acid in aqueous solution: Relevance in prebiotic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Negrón-Mendoza, A., E-mail: negron@nucleares.unam.mx; Ramos-Bernal, S. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, UNAM. Cd. Universitaria, A. P. 70-543, 04510 México, D. F. México (Mexico)

    2015-07-23

    The radiation chemistry of hydroxy acids like citric and isocitric acids is rather scarce, even though they are crucial compounds in biological systems and for food irradiation. The aim of this work is to study the radiolytic behavior of these acids focused on the interconversion induced by radiation of citric and isocitric acid into other members of the Krebs cycle. The results showed that among the products formed were succinic, malonic, malic and other acids related to metabolic pathways, and these results are correlated with its possible role in chemical evolution processes.

  8. Promysalin Elicits Species-Selective Inhibition of Pseudomonas aeruginosa by Targeting Succinate Dehydrogenase.

    Science.gov (United States)

    Keohane, Colleen E; Steele, Andrew D; Fetzer, Christian; Khowsathit, Jittasak; Van Tyne, Daria; Moynié, Lucile; Gilmore, Michael S; Karanicolas, John; Sieber, Stephan A; Wuest, William M

    2018-02-07

    Natural products have served as an inspiration to scientists both for their complex three-dimensional architecture and exquisite biological activity. Promysalin is one such Pseudomonad secondary metabolite that exhibits narrow-spectrum antibacterial activity, originally isolated from the rhizosphere. We herein utilize affinity-based protein profiling (AfBPP) to identify succinate dehydrogenase (Sdh) as the biological target of the natural product. The target was further validated in silico, in vitro, in vivo, and through the selection, and sequencing, of a resistant mutant. Succinate dehydrogenase plays an essential role in primary metabolism of Pseudomonas aeruginosa as the only enzyme that is involved both in the tricarboxylic acid cycle (TCA) and in respiration via the electron transport chain. These findings add credence to other studies that suggest that the TCA cycle is an understudied target in the development of novel therapeutics to combat P. aeruginosa, a significant pathogen in clinical settings.

  9. Synthesis, stability and bioavailability of astaxanthin succinate diester.

    Science.gov (United States)

    Qiao, Xing; Yang, Lu; Zhang, Ting; Zhou, Qingxin; Wang, Yuming; Xu, Jie; Xue, Changhu

    2018-06-01

    We synthesized astaxanthin succinate diester (ASD), a novel astaxanthin (AST) derivate, with succinic anhydride and free AST. ASD was purified and characterized using silica gel column chromatography and spectrometry, respectively. The ASD final synthesis rate was 82.63%. A stability test revealed a high AST and ASD retention rate at pH 5.0-7.0. ASD showed better stability than did AST under acidic conditions. Both sample ions showed lower retention rates under Fe 2+ and Fe 3+ states. The ASD metabolic curve showed serum and liver area under the curve from 0 h to time t (AUC 0-t ) values of 45.05 ± 4.58 and 120.38 ± 23.66 µg h -1  mL -1 , respectively. The long-term accumulation was significantly higher in the ASD group than in the AST group, which showed higher accumulation in the heart, muscle and spleen than in other tissues in vivo. The thermal stability and bioavailability of ASD were higher than that of the non-esterified free AST and common free AST, respectively. Additionally, AST accumulation in different tissues of the ASD group was multifold higher than that of free AST. These results prove that ASD may serve as a better source of AST for human nutrition than does free AST. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Natural 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®)

    OpenAIRE

    Wilfried Schwab

    2013-01-01

    4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these c...

  11. Miscibility, crystallization and mechanical properties of biodegradable blends of poly(L-lactic acid) and poly(butylene succinate-b-ethylene succinate) multiblock copolymer

    International Nuclear Information System (INIS)

    Jiao, Ling; Huang, Cai-Li; Zeng, Jian-Bing; Wang, Yu-Zhong; Wang, Xiu-Li

    2012-01-01

    Highlights: ► The blend of PLLA and PBES showed limited miscibility. ► The crystallization rate of PLLA was accelerated by blending with PBES. ► The crystal structures of PLLA and PBES did not change. - Abstract: Poly(L-lactic acid) (PLLA) is regarded as one of the most promising biobased and biodegradable polymers. However, its application was restricted due to the brittle nature. In the present study, PLLA was blended with a novel biodegradable flexible multiblock copolymer, poly(butylene succinate-b-ethylene succinate) (PBES) to produce new biodegradable materials. PLLA/PBES blends with different composition were prepared by solution blending and casting method with chloroform as a mutual solvent. Miscibility, crystallization behavior, and mechanical properties of the blends were investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and tensile tests. The results indicated that PLLA and PBES showed limited miscibility in the amorphous phase. The crystallization rate of PLLA was accelerated with the increase of PBES in the blends while the crystallization mechanism did not change. The results of tensile tests suggest that the blends showed longer elongation at break than neat PLLA. The elongation at break of PLLA was obtained to be 10%, and those of PLLA/PBES 80/20, 60/40, 40/60 and 20/80 were 29, 110, 442, and 455%, respectively.

  12. Fabrication of Chitin/Poly(butylene succinate/Chondroitin Sulfate Nanoparticles Ternary Composite Hydrogel Scaffold for Skin Tissue Engineering

    Directory of Open Access Journals (Sweden)

    S. Deepthi

    2014-12-01

    Full Text Available Skin loss is one of the oldest and still not totally resolved problems in the medical field. Since spontaneous healing of the dermal defects would not occur, the regeneration of full thickness of skin requires skin substitutes. Tissue engineering constructs would provide a three dimensional matrix for the reconstruction of skin tissue and the repair of damage. The aim of the present work is to develop a chitin based scaffold, by blending it with poly(butylene succinate (PBS, an aliphatic, biodegradable and biocompatible synthetic polymer with excellent mechanical properties. The presence of chondroitin sulfate nanoparticles (CSnp in the scaffold would favor cell adhesion. A chitin/PBS/CSnp composite hydrogel scaffold was developed and characterized by SEM (Scanning Electron Microscope, FTIR (Fourier Transform Infrared Spectroscopy, and swelling ratio of scaffolds were analyzed. The scaffolds were evaluated for the suitability for skin tissue engineering application by cytotoxicity, cell attachment, and cell proliferation studies using human dermal fibroblasts (HDF. The cytotoxicity and cell proliferation studies using HDF confirm the suitability of the scaffold for skin regeneration. In short, these results show promising applicability of the developed chitin/PBS/CSnps ternary composite hydrogel scaffolds for skin tissue regeneration.

  13. Enolate Stabilization by Anion-π Interactions: Deuterium Exchange in Malonate Dilactones on π-Acidic Surfaces.

    Science.gov (United States)

    Miros, François N; Zhao, Yingjie; Sargsyan, Gevorg; Pupier, Marion; Besnard, Céline; Beuchat, César; Mareda, Jiri; Sakai, Naomi; Matile, Stefan

    2016-02-18

    Of central importance in chemistry and biology, enolate chemistry is an attractive topic to elaborate on possible contributions of anion-π interactions to catalysis. To demonstrate the existence of such contributions, experimental evidence for the stabilization of not only anions but also anionic intermediates and transition states on π-acidic aromatic surfaces is decisive. To tackle this challenge for enolate chemistry with maximal precision and minimal uncertainty, malonate dilactones are covalently positioned on the π-acidic surface of naphthalenediimides (NDIs). Their presence is directly visible in the upfield shifts of the α-protons in the (1) H NMR spectra. The reactivity of these protons on π-acidic surfaces is measured by hydrogen-deuterium (H-D) exchange for 11 different examples, excluding controls. The velocity of H-D exchange increases with π acidity (NDI core substituents: SO2 R>SOR>H>OR>OR/NR2 >SR>NR2 ). The H-D exchange kinetics vary with the structure of the enolate (malonates>methylmalonates, dilactones>dithiolactones). Moreover, they depend on the distance to the π surface (bridge length: 11-13 atoms). Most importantly, H-D exchange depends strongly on the chirality of the π surface (chiral sulfoxides as core substituents; the crystal structure of the enantiopure (R,R,P)-macrocycle is reported). For maximal π acidity, transition-state stabilizations up to -18.8 kJ mol(-1) are obtained for H-D exchange. The Brønsted acidity of the enols increases strongly with π acidity of the aromatic surface, the lowest measured pKa =10.9 calculates to a ΔpKa =-5.5. Corresponding to the deprotonation of arginine residues in neutral water, considered as "impossible" in biology, the found enolate-π interactions are very important. The strong dependence of enolate stabilization on the unprecedented seven-component π-acidity gradient over almost 1 eV demonstrates quantitatively that such important anion-π activities can be expected only from

  14. Direct dimethyl ether fueling of a high temperature polymer fuel cell

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Vassiliev, Anton; Olsen, M.I.

    2012-01-01

    Direct dimethyl ether (DME) fuel cells suffer from poor DME–water miscibility and so far peak powers of only 20–40 mW cm−2 have been reported. Based on available literature on solubility of dimethyl ether (DME) in water at ambient pressure it was estimated that the maximum concentration of DME at...

  15. Further studies of the thermal and photochemical diels-alder reactions of N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) with naphthalene and some substituted naphthalenes

    Science.gov (United States)

    Breton; Newton

    2000-05-19

    MeTAD thermally reacted with naphthalene (2) and methylated naphthalenes to give equilibrium mixtures of starting materials and [4 + 2] cycloadducts. Methyl substitution on the naphthalene ring generally increased both the amount of cycloadduct formed and the rate of cycloaddition relative to 2. The isolated cycloadducts were all thermally labile and quantitatively reverted to the parent naphthalene in the presence of 2,3-dimethyl-2-butene as a trap for liberated MeTAD. The rates of the cycloreversion reactions were affected by substitution patterns but not appreciably by solvent. A mechanism for the cycloaddition reaction is presented that proposes the involvement of a charge-transfer complex. Photochemically, MeTAD demonstrated lower regioselectivity in its reactions with substituted naphthalenes relative to the corresponding thermal reactions.

  16. Management Strategies to Facilitate Optimal Outcomes for Patients Treated with Delayed-release Dimethyl Fumarate.

    Science.gov (United States)

    Mayer, Lori; Fink, Mary Kay; Sammarco, Carrie; Laing, Lisa

    2018-04-01

    Delayed-release dimethyl fumarate is an oral disease-modifying therapy that has demonstrated significant efficacy in adults with relapsing-remitting multiple sclerosis. Incidences of flushing and gastrointestinal adverse events are common in the first month after delayed-release dimethyl fumarate initiation. Our objective was to propose mitigation strategies for adverse events related to initiation of delayed-release dimethyl fumarate in the treatment of patients with multiple sclerosis. Studies of individually developed mitigation strategies and chart reviews were evaluated. Those results, as well as mitigation protocols developed at multiple sclerosis care centers, are summarized. Key steps to optimize the effectiveness of delayed-release dimethyl fumarate treatment include education prior to and at the time of delayed-release dimethyl fumarate initiation, initiation dose protocol gradually increasing to maintenance dose, dietary suggestions for co-administration with food, gastrointestinal symptom management with over-the-counter medications, flushing symptom management with aspirin, and temporary dose reduction. Using the available evidence from clinical trials and evaluations of post-marketing studies, these strategies to manage gastrointestinal and flushing symptoms can be effective and helpful to the patient when initiating delayed-release dimethyl fumarate.

  17. Ferulenol specifically inhibits succinate ubiquinone reductase at the level of the ubiquinone cycle

    International Nuclear Information System (INIS)

    Lahouel, Mesbah; Zini, Roland; Zellagui, Ammar; Rhouati, Salah; Carrupt, Pierre-Alain; Morin, Didier

    2007-01-01

    The natural compound ferulenol, a sesquiterpene prenylated coumarin derivative, was purified from Ferula vesceritensis and its mitochondrial effects were studied. Ferulenol caused inhibition of oxidative phoshorylation. At low concentrations, ferulenol inhibited ATP synthesis by inhibition of the adenine nucleotide translocase without limitation of mitochondrial respiration. At higher concentrations, ferulenol inhibited oxygen consumption. Ferulenol caused specific inhibition of succinate ubiquinone reductase without altering succinate dehydrogenase activity of the complex II. This inhibition results from a limitation of electron transfers initiated by the reduction of ubiquinone to ubiquinol in the ubiquinone cycle. This original mechanism of action makes ferulenol a useful tool to study the physiological role and the mechanism of electron transfer in the complex II. In addition, these data provide an additional mechanism by which ferulenol may alter cell function and demonstrate that mitochondrial dysfunction is an important determinant in Ferula plant toxicity

  18. Synthesis, Spectroscopic and Theoretical Studies of New Quaternary N,N-Dimethyl-3-phthalimidopropylammonium Conjugates of Sterols and Bile Acids

    Directory of Open Access Journals (Sweden)

    Bogumil Brycki

    2014-04-01

    Full Text Available New quaternary 3-phthalimidopropylammonium conjugates of steroids were obtained by reaction of sterols (ergosterol, cholesterol, cholestanol and bile acids (lithocholic, deoxycholic, cholic with bromoacetic acid bromide to give sterol 3β-bromoacetates and bile acid 3α-bromoacetates, respectively. These intermediates were subjected to nuclephilic substitution with N,N-dimethyl-3-phthalimidopropylamine to give the final quaternary ammonium salts. The structures of products were confirmed by spectral (1H-NMR, 13C-NMR, and FT-IR analysis, mass spectrometry (ESI-MS, MALDI as well as PM5 semiempirical methods and B3LYP ab initio methods. Estimation of the pharmacotherapeutic potential has been accomplished for synthesized compounds on the basis of Prediction of Activity Spectra for Substances (PASS.

  19. Integration of Succinic Acid Production in a Dry Mill Ethanol Facility

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-08-01

    This project seeks to address both issues for a dry mill ethanol biorefinery by lowering the cost of sugars with the development of an advanced pretreatment process, improving the economics of succinic acid (SA), and developing a model of an ethanol dry mill to evaluate the impact of adding different products and processes to a dry mill.

  20. Double Michael Addition Reaction of Bischalcone under Ultrasound

    Institute of Scientific and Technical Information of China (English)

    LI,Ji-Tai; XU,Wen-Zhi; CHEN,Guo-Feng; LI,Tong-Shuang

    2004-01-01

    @@ The Michael addition of 1,5-diaryl-1,4-pentadien-3-ones with active methylene compounds has been the subjects of many investigations. Ultrasound has increasingly been used in organic synthesis in the last three decades. Compared with traditional methods, this method is more convenient and easily controlled. A large number of organic reactions can be carried out in higher yield, shorter reaction time or milder conditions under ultrasonic irradiation. KF/Al2O3 as a useful solid supported catalyst has received considerable attention because of their high level of chemoselectivity and environmental compatibility as well as simplicity of operation and their ready availability at low cost. Herein we report the double Michael addition of dibenzalacetone with active methlene compounds such as dimethyl malonate, diethyl malonate,methyl cyanoacetate and ethyl cyanoacetate catalyzed by KF/Al2O3 under ultrasound irradiation.

  1. Role of O2 in the Growth of Rhizobium leguminosarum bv. viciae 3841 on Glucose and Succinate

    OpenAIRE

    Wheatley, Rachel M.; Ramachandran, Vinoy K.; Geddes, Barney A.; Perry, Benjamin J.; Yost, Chris K.; Poole, Philip S.

    2016-01-01

    Insertion sequencing (INSeq) analysis of Rhizobium leguminosarum bv. viciae 3841 (Rlv3841) grown on glucose or succinate at both 21% and 1% O2 was used to understand how O2 concentration alters metabolism. Two transcriptional regulators were required for growth on glucose (pRL120207 [eryD] and RL0547 [phoB]), five were required on succinate (pRL100388, RL1641, RL1642, RL3427, and RL4524 [ecfL]), and three were required on 1% O2 (pRL110072, RL0545 [phoU], and RL4042). A novel toxin-antitoxin s...

  2. Stable isotope dimethyl labelling for quantitative proteomics and beyond

    Science.gov (United States)

    Hsu, Jue-Liang; Chen, Shu-Hui

    2016-01-01

    Stable-isotope reductive dimethylation, a cost-effective, simple, robust, reliable and easy-to- multiplex labelling method, is widely applied to quantitative proteomics using liquid chromatography-mass spectrometry. This review focuses on biological applications of stable-isotope dimethyl labelling for a large-scale comparative analysis of protein expression and post-translational modifications based on its unique properties of the labelling chemistry. Some other applications of the labelling method for sample preparation and mass spectrometry-based protein identification and characterization are also summarized. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644970

  3. Blend membrane of succinic acid-crosslinked chitosan grafted with heparin/PVA-PEG (polyvinyl alcohol-polyethylene glycol) and its characterization

    Science.gov (United States)

    Sangkota, V. D. A.; Lusiana, R. A.; Astuti, Y.

    2018-04-01

    Crosslinking and grafting reactions are required to modify the functional groups on chitosan to increase the number of its active groups. In this study, crosslinking reaction of succinic acid and grafting reaction of heparin on chitosan were conducted to produce a membrane as a candidate of a hemodialysis membrane. The mole ratio between chitosan and succinate acids was varied to obtain the best composition of modified materials. By blending all the material composition with PVA-PEG, the blend was transformed into a membrane. The resulted membrane was then characterized by various test methods such as tests of thickness, weight, water uptake, pH resistance, tensile strength and membrane hydrophilicity. The results showed that the best composition of the membrane reached in the addition of 0.011 gram of succinic acid proved by its highest mechanical strength compared to the other membranes.

  4. Multi-catalysis cascade reactions based on the methoxycarbonylketene platform: diversity-oriented synthesis of functionalized non-symmetrical malonates for agrochemicals and pharmaceuticals.

    Science.gov (United States)

    Ramachary, Dhevalapally B; Venkaiah, Chintalapudi; Reddy, Y Vijayendar; Kishor, Mamillapalli

    2009-05-21

    In this paper we describe new multi-catalysis cascade (MCC) reactions for the one-pot synthesis of highly functionalized non-symmetrical malonates. These metal-free reactions are either five-step (olefination/hydrogenation/alkylation/ketenization/esterification) or six-step (olefination/hydrogenation/alkylation/ketenization/esterification/alkylation), and employ aldehydes/ketones, Meldrum's acid, 1,4-dihydropyridine/o-phenylenediamine, diazomethane, alcohols and active ethylene/acetylenes, and involve iminium-, self-, self-, self- and base-catalysis, respectively. Many of the products have direct application in agricultural and pharmaceutical chemistry.

  5. [Pathomorphology of regenerative processes in mandibular fracture after sodium succinate treatment and laser magnetotherapy in an experimental setting].

    Science.gov (United States)

    Faustov, L A; Nedel'ko, N A; Morozova, M V

    2001-01-01

    Morphological reactions in tissue adjacent to mandibular angular fracture were studied in guinea pigs treated with sodium succinate and laser magnetotherapy. Due to succinate therapy the exudative component of inflammation was less expressed in comparison with the control, macrophagal reaction and neoangiogenesis were activated, the volume of damaged muscle tissue and the incidence of suppurations decreased. The number of osteoblasts increased and new bone structures acquired a lamellar pattern earlier than in the control. Sodium succinate therapy in combination with laser magnetotherapy had a more pronounced positive effect as regards activation of macrophagal reaction and neoangiogenesis and a decrease in the area of fibrosclerotic changes in the zone of damaged muscles, where newly formed myosymplasts differentiated into myotubes and even in muscle fibers. Suppuration of the wound was prevented. Bone tissue in the fracture zone formed without preliminary formation of cartilaginous tissue, which resulted in more rapid osteogenesis (lamellar bone growth in the fracture zone).

  6. EPR-study of reversible oxygenation process of coordination compounds of cobalt(II) with S-substituted N1,N4-di(salicylidene)-isothiosemicarbazides

    International Nuclear Information System (INIS)

    Gerbeleu, N.V.; Revenko, M.D.; Rusu, V.G.; Shames, A.T.

    1987-01-01

    The reaction between molecular oxygen and coordination compounds of cobalt(II) with S-substituted N 1 ,N 4 -di(salicylidene)isothiosemicarbazides in dimethyl sulfoxide solution was studied by the EPR method. It was found that paramagnetic monomeric adducts and diamagnetic μ-peroxo-dimers are formed. The spin-Hamiltonian parameters of the EPR spectra of the initial cobalt complexes, as well as of the paramagnetic adducts were determined. The nature of the Co-O 2 bond is discussed

  7. Synthesis 1-(5-oxohexyl)-3,7-dimethyl-xanthyne labelled with tritium into 8 position from purinic ring

    International Nuclear Information System (INIS)

    Mihaila, V.; Corol, D.

    1999-01-01

    This paper presents the work on synthesis of 1-(5-oxohexyl)-3,7-dimethyl-xanthyne labelled with tritium into 8 position from purinic ring. The obtaining of tritium labelled compound is realized by initial labelling of theobromine with tritium into 8 position and by coupling the purinic derivative to 1-Br-5-hexanone. Theobromine-8- 3 H was obtained by the bromination of theobromine with elementary bromine and after that the bromine was substituted with tritium i.e.: C 7 H 8 O 2 N 4 theobromine Br 2 /(-HBr) C 7 H 7 O 2 N 4 Br (8-Br-theobromine) ( 3 H 2 /cat)/(-KOH) C 7 H 7 3 HO 2 N 4 (theobromine-8- 3 H). Theobromine-8- 3 H was purified by thin layer chromatography with a solvent system i.e. n-BuOH:AcOH:H 2 O (4:1:1, v/v/v) and characterized radiochemically. It was then diluted by unlabelled theobromine to specific activity of 50 mCi/g. After dilution, theobromine-8- 3 H was coupled to 1-Br-5-hexanone i.e.: C 7 H 7 3 HO 2 N 4 (theobromine-8- 3 H) + Br-(CH 2 ) 4 -CO-CH 3 (1-Br-5-hexanone) (NaOH)/(CH 3 OH) C 13 H 17 3 HO 3 N 4 (1-(5-oxohexyl)- 3,7-dimethyl-xanthine-8- 3 H). The raw compound was purified by recrystallization from 2-propanol and it was characterized radiochemically. (authors)

  8. The liquid–liquid coexistence curves of {x dimethyl adipate + (1 − x) n-hexane} and {x dimethyl adipate + (1 − x) n-heptane} in the critical region

    International Nuclear Information System (INIS)

    Chen Zhiyun; Cai Li; Huang Meijun; Yin Tianxiang; An Xueqin; Shen Weiguo

    2012-01-01

    Highlights: ► Coexistence curves of (dimethyl adipate + n-hexane) (+n-heptane) were measured. ► The critical exponent β are consistent with the 3D-Ising value. ► The asymmetry of the coexistence curves were discussed by complete scaling theory. - Abstract: The liquid–liquid coexistence curves for (dimethyl adipate + n-hexane), (dimethyl adipate + n-heptane) have been measured, from which the critical amplitudes and the critical exponents are deduced. The critical exponent β corresponding to the coexistence curves are consistent with the 3D-Ising value. The experimental results have also been analyzed to determine the critical amplitudes of Wegner-correction terms when β and Δ are fixed at their theoretical values, and to examine the asymmetry of the diameters for the coexistence curves.

  9. Systems of cerium(3) nitrate-dimethyl amine nitrate-water and cerium(3) nitrate-dimethyl amine nitrate-water

    International Nuclear Information System (INIS)

    Mininkov, N.E.; Zhuravlev, E.F.

    1976-01-01

    Solubility of solid phases in the systems cerium(3)nitrate-water-dimethyl amine nitrate and cerium(3)nitrate-water-dimethyl amine nitrate has been st ed by the method of isothermal sections at 25 and 50 deo. C. It has been shown that one anhydrous compound is formed in each system with a ratio of cerium(3) nitrate to amine nitrate 1:5. The compounds formed in the systems have been separated from the corresponding solutions and studied by microcrystalloscopic, X-ray phase, thermal and infrared spectroscopic methods. On the basis of spectroscopic studies the following formula has been assigned to the compound: [(CH 3 ) 2 NH 2 + ] 5 x[Ce(NO 3 ) 8 ]. The thermal analysis of the compound has shown that its melting point is 106 deg C. The solubility isotherms in the system Ce(NO 3 ) 3 -H 2 O-(C 2 H 5 ) 2 NHxHNO 3 consist of three branches which intersect in two eutonic points

  10. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

    Science.gov (United States)

    2010-07-01

    ... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject to...

  11. Efficient and Simple Synthesis of 6-Aryl-1,4-dimethyl-9H-carbazoles

    Directory of Open Access Journals (Sweden)

    Sylvain Rault

    2008-06-01

    Full Text Available A synthetic method for the preparation of 6-aryl-1,4-dimethyl-9H-carbazoles involving a palladium catalyzed coupling reaction of 1,4-dimethyl-9H-carbazole-6-boronic acids and (heteroaryl halides is described.

  12. 21 CFR 172.133 - Dimethyl dicarbonate.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... treatment, filtration, or other technologies prior to the use of dimethyl dicarbonate: (1) In wine, dealcoholized wine, and low alcohol wine in an amount not to exceed 200 parts per million. (2) In ready-to-drink...

  13. Gamma-radiolysis of dimethyl sulfoxide. II. Radiolysis yields and possible mechanisms

    International Nuclear Information System (INIS)

    Gutierrez, M. C.; Barrera, R.

    1978-01-01

    As result of quantitative studies on gamma-radiolysis of DMSO at a dose range of 90-850 Mrads, constant G values have been obtained for the following radiolysis compounds: G(-DMSO) - 6.7 ±0.2; G(dimethyl sulphide) - 3.4 ±0.3; G(methane) - 0,75 ± 0.04; G(dimethyl disulphide) -0.33 ±0,03; G(tri methylsulphonium methanesulphonate) - 0.26 ± 0,01; G(methyl methanethiosulphonate) - 0,25 ±0.02; G(dimethyl sulphona)-0.21±0.02; G(H 2 )-0.18±0.02; and G(propane)--0.0092±0.0007. Initial G values have been obtained for other identified compounds: Gi(ethane)-0,46; Gi(CO)-0.052; and Gi(CO 2 )-0.030. Possible mechanisms on the radiolysis process are proposed. (Author) 17 refs

  14. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

    NARCIS (Netherlands)

    K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

    2008-01-01

    textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial

  15. Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae)

    OpenAIRE

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

    2017-01-01

    The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2S,3R)-3-hy?droxy-5-oxo-2,3,4,5-tetra?hydro?furan-2,3-di?carb?oxy?lic acid dimethyl sulfoxide monosolvate], C6H6O7?C2H6OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2S,3R)-3-hy?droxy-5-oxo-2,3,4,5-tetra?hydro?furan-2,3-di?carboxyl?ate], C8H10O7, (II). Compound (I) forms a layered structure with alternating laye...

  16. A study on complex formation of cadmium (II) ions, 9

    International Nuclear Information System (INIS)

    Matsui, Haruo

    1984-01-01

    Formation constants of cadmium (11) complexes with dicarboxylic acids such as oxalic, malonic, methylmalonic, succinic, and glutaric acids were determined in aqueous solutions containing 3 mol.dm -3 LiClO 4 as a constan ionic medium at 25 0 C by potentiometric titrations. It was reported in the previous works that cadmium (11)- aspartic acid complexes contained two chelate rings. However, a problem remained whether the second chelate ring could be formed by six membered-ring containing -O-Cd-N- bond or by seven membered-ring containing -O-Cd-O- bond. The results of the present work suggested that it would be formed by a six membered ring. Cadmium (11) ions were coordinated with a carboxylic group of the dicarboxylic acids studied, and formed no chelate ring within the complexes. The white precipitate appeared in the solution containing cadmium (11) ion and oxalic acid, in the pH range below 3.0, therefore, the chelate formation was not ascertained in this case. The formation constants, log βsub(pr)= log([Cdsub(p)Lsub(r)sup((2p-2r)+)]/([Cd 2+ ]sup(p)[L 2- ]sup(r))), of the complexes were: log β 11 = 1.98, log β 12 = 3.05 for cadmium (11)-malonic acid; log β 11 = 2.28, log β 12 = 3.06 for cadmium (11)-methylmalonic acid; log β 11 = 1.78, log β 12 = 3.08 for cadmium (11)-succinic acid; log β 11 = 1.85, log β 12 = 3.28 for cadmium (11)-glutaric acid complexes. (author)

  17. Development of chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis.

    Science.gov (United States)

    Davoudi, Zahra; Rabiee, Mohammad; Houshmand, Behzad; Eslahi, Niloofar; Khoshroo, Kimia; Rasoulianboroujeni, Morteza; Tahriri, Mohammadreza; Tayebi, Lobat

    2018-01-01

    The aim of this research was to develop chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis, which was fabricated through an environmental friendly process. Mucoadhesive films increase the advantage of higher efficiency and drug localization in the affected region. In this research, mucoadhesive films, for the release of hydrocortisone sodium succinate, were prepared using different ratios of chitosan, gelatin and keratin. In the first step, chitosan and gelatin proportions were optimized after evaluating the mechanical properties, swelling capacity, water uptake, stability, and biodegradation of the films. Then, keratin was added at different percentages to the optimum composite of chitosan and gelatin together with the drug. The results of surface pH showed that none of the samples were harmful to the buccal cavity. FTIR analysis confirmed the influence of keratin on the structure of the composite. The presence of a higher amount of keratin in the composite films resulted in high mechanical, mucoadhesive properties and stability, low water uptake and biodegradation in phosphate buffer saline (pH = 7.4) containing 10 4  U/ml lysozyme. The release profile of the films ascertained that keratin is a rate controller in the release of the hydrocortisone sodium succinate. Finally, chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate can be employed in dental applications.

  18. Synthesis, crystal structure, and spectra of 3,3- dimethyl-1-N-(1'-phenyl-2',3'-dimethyl-5'-oxo-3'- pyrazolin-4'-yl)imino-1,2,3,4-tetrahydroisoquinoline

    International Nuclear Information System (INIS)

    Sokol, V.I.; Ryabov, M.A.; Merkur'eva, N.Yu.; Davydov, V.V.; Zaitsev, B.E.; Shklyaev, Yu.V.; Sergienko, V.S.; Zaitsev, B.E.

    1996-01-01

    The synthesis and the crystal and molecular structure of 3,3-dimethyl-1-N-(1'-phenyl-2',3'- dimethyl-5'-oxo-3'-pyrazolin-4'-yl)imino-1,2,3,4-tetrahydroisoquinoline are reported. As is evidenced by the 1H NMR, IR, and electron spectra, the tautomeric form of the compounds observed in the crystal is also retained in solutions

  19. A novel preparation of methyl-β-cyclodextrin from dimethyl carbonate and β-cyclodextrin

    DEFF Research Database (Denmark)

    Gan, Yongjiang; Zhang, Yimin; Xiao, Chuanhao

    2011-01-01

    A novel green synthesis process about methyl-β-cyclodextrin has been investigated through the reaction between β-cyclodextrin and dimethyl carbonate by anhydrous potassium carbonate as catalyst in DMF. The influence of experimental factors including the molar ratio of dimethyl carbonate to β-cycl...

  20. Bisoprolol compared with carvedilol and metoprolol succinate in the treatment of patients with chronic heart failure.

    Science.gov (United States)

    Fröhlich, Hanna; Torres, Lorella; Täger, Tobias; Schellberg, Dieter; Corletto, Anna; Kazmi, Syed; Goode, Kevin; Grundtvig, Morten; Hole, Torstein; Katus, Hugo A; Cleland, John G F; Atar, Dan; Clark, Andrew L; Agewall, Stefan; Frankenstein, Lutz

    2017-09-01

    Beta-blockers are recommended for the treatment of chronic heart failure (CHF). However, it is disputed whether beta-blockers exert a class effect or whether there are differences in efficacy between agents. 6010 out-patients with stable CHF and a reduced left ventricular ejection fraction prescribed either bisoprolol, carvedilol or metoprolol succinate were identified from three registries in Norway, England, and Germany. In three separate matching procedures, patients were individually matched with respect to both dose equivalents and the respective propensity scores for beta-blocker treatment. During a follow-up of 26,963 patient-years, 302 (29.5%), 637 (37.0%), and 1232 (37.7%) patients died amongst those prescribed bisoprolol, carvedilol, and metoprolol, respectively. In univariable analysis of the general sample, bisoprolol and carvedilol were both associated with lower mortality as compared with metoprolol succinate (HR 0.80, 95% CI 0.71-0.91, p < 0.01, and HR 0.86, 95% CI 0.78-0.94, p < 0.01, respectively). Patients prescribed bisoprolol or carvedilol had similar mortality (HR 0.94, 95% CI 0.82-1.08, p = 0.37). However, there was no significant association between beta-blocker choice and all-cause mortality in any of the matched samples (HR 0.90; 95% CI 0.76-1.06; p = 0.20; HR 1.10, 95% CI 0.93-1.31, p = 0.24; and HR 1.08, 95% CI 0.95-1.22, p = 0.26 for bisoprolol vs. carvedilol, bisoprolol vs. metoprolol succinate, and carvedilol vs. metoprolol succinate, respectively). Results were confirmed in a number of important subgroups. Our results suggest that the three beta-blockers investigated have similar effects on mortality amongst patients with CHF.

  1. Intracellular product recycling in high succinic acid producing yeast at low pH

    NARCIS (Netherlands)

    Wahl, S.A.; Bernal Martinez, C.; Zhao, Zheng; van Gulik, W.M.; Jansen, Mickel L.A.

    2017-01-01

    Background: The metabolic engineering of Saccharomyces cerevisiae for the production of succinic acid has progressed dramatically, and a series of high-producing hosts are available. At low cultivation pH and high titers, the product transport can become bidirectional, i.e. the acid is reentering

  2. Direct C-H alkylation and indole formation of anilines with diazo compounds under rhodium catalysis.

    Science.gov (United States)

    Mishra, Neeraj Kumar; Choi, Miji; Jo, Hyeim; Oh, Yongguk; Sharma, Satyasheel; Han, Sang Hoon; Jeong, Taejoo; Han, Sangil; Lee, Seok-Yong; Kim, In Su

    2015-12-18

    The rhodium(III)-catalyzed direct functionalization of aniline C-H bonds with α-diazo compounds is described. These transformations provide a facile construction of ortho-alkylated anilines with diazo malonates or highly substituted indoles with diazo acetoacetates.

  3. USE OF DIMETHYL FUMARATE IN THE TREATMENT OF MULTIPLE SCLEROSIS: CLINICAL AND ECONOMIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    V. R. Mkrtchyan

    2016-01-01

    Full Text Available The paper presents a review of an update on the comparative pharmacoeconomic analysis of using dimethyl fumarate in the treatment of multiple sclerosis (MS in European countries. A pharmacoeconomic evaluation was made to study the use of first-line oral dimethyl fumarate versus another first-line oral teriflunomide in the treatment of MS in the Russian Federation (for 1 year and second-line natalizumab and fingolimod. Among first-line oral drugs, dimethyl fumarate was shown to be superior to teriflunomide in a cost-effectiveness ratio and to be slightly ahead of the MS-modifying drugs (MSMDs  and the second-line drugs natalizumab and fingolimod. According to clinical and economic indicators, dimethyl fumarate is the drug of choise among other MSMDs in the treatment of MS.

  4. Modeling of a Reaction-Distillation-Recycle System to Produce Dimethyl Ether through Methanol Dehydration

    Science.gov (United States)

    Muharam, Y.; Zulkarnain, L. M.; Wirya, A. S.

    2018-03-01

    The increase in the dimethyl ether yield through methanol dehydration due to a recycle integration to a reaction-distillation system was studied in this research. A one-dimensional phenomenological model of a methanol dehydration reactor and a shortcut model of distillation columns were used to achieve the aim. Simulation results show that 10.7 moles/s of dimethyl ether is produced in a reaction-distillation system with the reactor length being 4 m, the reactor inlet pressure being 18 atm, the reactor inlet temperature being 533 K, the reactor inlet velocity being 0.408 m/s, and the distillation pressure being 8 atm. The methanol conversion is 90% and the dimethyl ether yield is 48%. The integration of the recycle stream to the system increases the dimethyl ether yield by 8%.

  5. Effects of primary dicarboxylic acids on microstructure and mechanical properties of sub-microcrystalline Ni-Co alloys

    International Nuclear Information System (INIS)

    Vijayakumar, J.; Mohan, S.; Yadav, S. Sunil

    2011-01-01

    Highlights: → The electrodeposited Ni-Co alloys are mostly used in magnetic sensors and it has good mechanical and corrosion resistance properties. → The effect of dicarboxylic acid leads to preferred (2 0 0) crystalline orientation, this may improve magnetic properties dicarboxylic acid can alter the elemental composition of Ni-Co alloy. → Dicarboxylic acid acts as a good brightner. - Abstract: Nickel-cobalt alloys were deposited from sulfate electrolyte with oxalic, malonic and succinic acids as additives and their microstructure and mechanical properties were studied. The crystal structure, surface morphologies, and chemical composition of coatings were investigated using X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy. The crystal structure and surface morphology analysis showed that the addition of dicarboxylic acid leads to (2 0 0) crystal face and the surface were more compact and uniform due to the grain refining. Ni 60 -Co 40 alloy was achieved when succinic acid is used as additive.

  6. Alpha-tocopheryl succinate inhibits malignant mesothelioma by disrupting the fibroblast growth factor autocrine loop

    Czech Academy of Sciences Publication Activity Database

    Stapelberg, M.; Gellert, N.; Swettenham, E.; Tomasetti, M.; Witting, P. K.; Procopio, A.; Neužil, Jiří

    2005-01-01

    Roč. 280, č. 27 (2005), s. 25369-25376 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50520514 Keywords : alpha-tocopheryl succinate * malignant mesothelioma * fibroblast growth factor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.854, year: 2005

  7. Tocopherol-associated protein-1 accelerates apoptosis induced by alpha-tocopheryl succinate in mesothelioma cells

    Czech Academy of Sciences Publication Activity Database

    Neužil, Jiří; Dong, L.F.; Wang, X.F.; Zingg, J.M.

    2006-01-01

    Roč. 343, č. 4 (2006), s. 1113-1117 ISSN 0006-291X Institutional research plan: CEZ:AV0Z50520514 Keywords : apoptosis * tocopherol-associated protein * alpha-tocopheryl succinate Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.855, year: 2006

  8. Biosynthesis of glycerol carbonate from glycerol by lipase in dimethyl carbonate as the solvent.

    Science.gov (United States)

    Lee, Kyung Hwa; Park, Chang-Ho; Lee, Eun Yeol

    2010-11-01

    Glycerol carbonate was synthesized from renewable glycerol and dimethyl carbonate using lipase in solvent-free reaction system in which excess dimethyl carbonate played as the reaction medium. A variety of lipases have been tested for their abilities to catalyze transesterification reaction, and Candida antartica lipase B and Novozyme 435 exhibited higher catalytic activities. The silica-coated glycerol with a 1:1 ratio was supplied to prevent two-phase formation between hydrophobic dimethyl carbonate and hydrophilic glycerol. Glycerol carbonate was successfully synthesized with more than 90% conversion from dimethyl carbonate and glycerol with a molar ratio of 10 using Novozyme 435-catalyzed transesterification at 70 °C. The Novozyme 435 [5% (w/w) and 20% (w/w)] and silica gel were more than four times recycled with good stability in a repeated batch operation for the solvent-free synthesis of glycerol carbonate.

  9. The ALDH21 gene found in lower plants and some vascular plants codes for a NADP+ -dependent succinic semialdehyde dehydrogenase.

    Science.gov (United States)

    Kopečná, Martina; Vigouroux, Armelle; Vilím, Jan; Končitíková, Radka; Briozzo, Pierre; Hájková, Eva; Jašková, Lenka; von Schwartzenberg, Klaus; Šebela, Marek; Moréra, Solange; Kopečný, David

    2017-10-01

    Lower plant species including some green algae, non-vascular plants (bryophytes) as well as the oldest vascular plants (lycopods) and ferns (monilophytes) possess a unique aldehyde dehydrogenase (ALDH) gene named ALDH21, which is upregulated during dehydration. However, the gene is absent in flowering plants. Here, we show that ALDH21 from the moss Physcomitrella patens codes for a tetrameric NADP + -dependent succinic semialdehyde dehydrogenase (SSALDH), which converts succinic semialdehyde, an intermediate of the γ-aminobutyric acid (GABA) shunt pathway, into succinate in the cytosol. NAD + is a very poor coenzyme for ALDH21 unlike for mitochondrial SSALDHs (ALDH5), which are the closest related ALDH members. Structural comparison between the apoform and the coenzyme complex reveal that NADP + binding induces a conformational change of the loop carrying Arg-228, which seals the NADP + in the coenzyme cavity via its 2'-phosphate and α-phosphate groups. The crystal structure with the bound product succinate shows that its carboxylate group establishes salt bridges with both Arg-121 and Arg-457, and a hydrogen bond with Tyr-296. While both arginine residues are pre-formed for substrate/product binding, Tyr-296 moves by more than 1 Å. Both R121A and R457A variants are almost inactive, demonstrating a key role of each arginine in catalysis. Our study implies that bryophytes but presumably also some green algae, lycopods and ferns, which carry both ALDH21 and ALDH5 genes, can oxidize SSAL to succinate in both cytosol and mitochondria, indicating a more diverse GABA shunt pathway compared with higher plants carrying only the mitochondrial ALDH5. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  10. 76 FR 59141 - Determination That LOXITANE (Loxapine Succinate) Capsules and Three Other Drug Products Were Not...

    Science.gov (United States)

    2011-09-23

    ... Applicant NDA 017525 LOXITANE (loxapine Watson Laboratories succinate) Inc., 417 Wakara Capsules, Way, Suite.../milliliter. NDA 020828 FORTOVASE Hoffmann La Roche (saquinavir) Inc., 340 Kingsland Capsule, 200 mg. St...

  11. Physical and chemical stability of palonosetron hydrochloride with dacarbazine and with methylprednisolone sodium succinate during simulated y-site administration.

    Science.gov (United States)

    Trissel, Lawrence A; Zhang, Yanping; Xu, Quanyun A

    2006-01-01

    The objective of this study was to evaluate the physical and chemical stability of mixtures of undiluted palonosetron hydrochloride 50 micrograms/mL with dacarbazine 4 mg/mL and with methylprednisolone sodium succinate 5 mg/mL in 5% dextrose injection during simulated Y-site administration. Triplicate test samples were prepared by admixing 7.5 mL of palonosetron hydrochloride with 7.5 mL of dacarbazine solution and, separately, methylprednisolone sodium succinate solution. Physical stability was assessed by using a multistep evaluation procedure that included both turbidimetric and particulate measurement as well as visual inspection. Chemical stability was assessed by using stability-indicating high-performance liquid chromatographic analytical techniques that determined drug concentrations. Evaluations were performed immediately after mixing and 1 and 4 hours after mixing. The palonosetron hydrochloride-dacarbazine samples were clear and colorless when viewed in normal fluorescent room light and when viewed with a Tyndall beam. Measured turbidities remained unchanged; particulate contents were low and exhibited little change. High-performance liquid chromatography analysis revealed that palonosetron hydrochloride and dacarbazine remained stable throughout the 4-hour test with no drug loss. Palonosetron hydrochloride is, therefore, physically compatible and chemically stable with dacarbazine during Y-site administration. Within 4 hours, the mixtures of palonosetron hydrochloride and methylprednisolone sodium succinate developed a microprecipitate that became a white precipitate visible to the unaided eye. The precipitate was analyzed and identified as methylprednisolone. Palonosetron hydrochloride is incompatible with methylprednisolone sodium succinate.

  12. Low-Temperature Oxidation of Dimethyl Ether to Polyoxymethylene Dimethyl Ethers over CNT-Supported Rhenium Catalyst

    Directory of Open Access Journals (Sweden)

    Qingde Zhang

    2016-03-01

    Full Text Available Due to its excellent conductivity, good thermal stability and large specific surface area, carbon nano-tubes (CNTs were selected as support to prepare a Re-based catalyst for dimethyl ether (DME direct oxidation to polyoxymethylene dimethyl ethers (DMMx. The catalyst performance was tested in a continuous flow type fixed-bed reactor. H3PW12O40 (PW12 was used to modify Re/CNTs to improve its activity and selectivity. The effects of PW12 content, reaction temperature, gas hourly space velocity (GHSV and reaction time on DME oxidation to DMMx were investigated. The results showed that modification of CNT-supported Re with 30% PW12 significantly increased the selectivity of DMM and DMM2 up to 59.0% from 6.6% with a DME conversion of 8.9%; besides that, there was no COx production observed in the reaction under the optimum conditions of 513 K and 1800 h−1. The techniques of XRD, BET, NH3-TPD, H2-TPR, XPS, TEM and SEM were used to characterize the structure, surface properties and morphology of the catalysts. The optimum amount of weak acid sites and redox sites promotes the synthesis of DMM and DMM2 from DME direct oxidation.

  13. Optimal conditions in direct dimethyl ether synthesis from syngas utilizing a dual-type fluidized bed reactor

    International Nuclear Information System (INIS)

    Yousefi, Ahmad; Eslamloueyan, Reza; Kazerooni, Nooshin Moradi

    2017-01-01

    Concerns over environmental pollution and ever-increasing energy demand have urged the global community to tap clean-burning fuels among which dimethyl ether is a promising candidate for contribution in the transportation sector. Direct dimethyl ether synthesis from syngas, in which methanol production and dehydration take place simultaneously, is arguably the preferred route for large scale production. In this study, direct dimethyl ether synthesis is proposed in an industrial dual-type fluidized bed reactor. This configuration involves two fluidized bed reactors operating in different conditions. In the first catalytic reactor (water-cooled reactor), the synthesis gas is partly converted to methanol after being preheated by the reaction heat in the second reactor (gas-cooled reactor). A two-phase generalized comprehensive reactor model, comprised of the flow in three different regimes is applied and a smooth transition between flow regimes is provided based on the probabilistic averaging approach. The optimal operating conditions are sought by employing differential evolution algorithm as a robust optimization strategy. The dimethyl ether mole fraction is considered as the objective function during the optimization. The results show considerable dimethyl ether enhancement by 16% and 14% compared to the conventional direct dimethyl ether synthesis reactor and dual-type fixed bed dimethyl ether reactor arrangements, respectively. - Highlights: • Dual-type catalytic fluidized bed reactors for dimethyl ether synthesis is studied. • A two-phase comprehensive model comprised of flow in three regimes is used. • Probabilistic averaging approach is applied for smooth transitions between regimes. • Differential evolution method is employed to determine optimal operating conditions. • Production capacity is remarkably enhanced compared to conventional reactor.

  14. trans-Dichlorido­bis(3,4-dimethyl­pyridine)platinum(II)

    Science.gov (United States)

    Chernyshev, Alexander N.; Bokach, Nadezhda A.; Izotova, Youlia A.; Haukka, Matti

    2009-01-01

    In the title compound, trans-[PtCl2(C7H9N)2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethyl­pyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar. PMID:21581530

  15. Alpha-Tocopheryl succinate causes mitochondrial permeabilization by preferential formation of Bak channels

    Czech Academy of Sciences Publication Activity Database

    Procházka, L.; Dong, L.F.; Vališ, Karel; Freeman, R.; Ralph, S.J.; Turánek, J.; Neužil, Jiří

    2010-01-01

    Roč. 15, č. 7 (2010), s. 782-794 ISSN 1360-8185 R&D Projects: GA AV ČR(CZ) KAN200520703; GA AV ČR(CZ) IAA500520702; GA AV ČR(CZ) IAA500520602 Institutional research plan: CEZ:AV0Z50520701 Keywords : Vitamin E succinate * apoptosis * Noxa-Bak Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.397, year: 2010

  16. Antioxidant properties of dimethyl sulfoxide and its viability as a solvent in the evaluation of neuroprotective antioxidants.

    Science.gov (United States)

    Sanmartín-Suárez, Carolina; Soto-Otero, Ramón; Sánchez-Sellero, Inés; Méndez-Álvarez, Estefanía

    2011-01-01

    Dimethyl sulfoxide is an amphiphilic compound whose miscibility with water and its ability to dissolve lipophilic compounds make it an appreciated solvent in biomedical research. However, its reported antioxidant properties raise doubts about its use as a solvent in evaluating new antioxidants. The goal of this investigation was to evaluate its antioxidant properties and carry out a comparative study on the antioxidant properties of some known neuroprotective antioxidants in the presence and absence of dimethyl sulfoxide. The antioxidant properties of dimethyl sulfoxide were studied in rat brain homogenates by determining its ability to reduce both lipid peroxidation (TBARS formation) and protein oxidation (increase in protein carbonyl content and decrease in free thiol content) induced by ferrous chloride/hydrogen peroxide. Its ability to reduce the production of hydroxyl radicals by 6-hydroxydopamine autoxidation was also estimated. The same study was also performed with three known antioxidants (α-phenyl-N-tert-butylnitrone; 2-methyl-2-nitrosopropane; 5,5-dimethyl-1-pyrroline N-oxide) in the presence and absence of dimethyl sulfoxide. Our results showed that dimethyl sulfoxide is able to reduce both lipid peroxidation and protein carbonyl formation induced by ferrous chloride/hydrogen peroxide in rat brain homogenates. It can also reduce the production of hydroxyl radicals during 6-hydroxydopamine autoxidation. However, it increases the oxidation of protein thiol groups caused by ferrous chloride/hydrogen peroxide in rat brain homogenate. Despite the here reported antioxidant and pro-oxidant properties of dimethyl sulfoxide, the results obtained with α-phenyl-N-tert-butylnitrone, 2-methyl-2-nitrosopropane, and 5,5-dimethyl-1-pyrroline N-oxide corroborate the antioxidant properties attributed to these compounds and support the potential use of dimethyl sulfoxide as a solvent in the study of the antioxidant properties of lipophilic compounds. Dimethyl sulfoxide

  17. Incorporation of 14C-succinate in Synechococcus

    International Nuclear Information System (INIS)

    Doehler, G.

    1983-01-01

    The cyanobacterium Synechococcus (= Anacystis nidulans) was grown under normal air conditions (0.03 vol.% CO 2 ) and in low white light (0.5 x 10 3 μW/cm 2 ) at 37 0 C. Kinetics of 14 C incorporation into several soluble products and pigments were studied after adding 14 C-succinate during photosynthesis and in the dark using the autoradiographic method. Radioactivity was found mainly in glutamate and aspartate during the photosynthetic period independent on 3-(3',4'-dichlorphenyl)-1,1-dimethylurea preincubation. In the dark period 14 C label could also be detected in malate. Short-term kinetics experiments showed a decrease in 14 C label of glutamate and a parallel increase of aspartate. Results were discussed in respect to the interrupted tricarboxylic acid cycle. (author)

  18. Triphenylsilane-substituted arenes as host materials for use in green phosphorescent organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jwajin; Lee, Kum Hee; Kim, Young Seok; Lee, Hyun Woo [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Ho Won [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2016-03-15

    We demonstrated triphenylsilane-substituted arenes (1–4) as host materials for green phosphorescent organic light-emitting diodes. Particularly, a device using 9,9-dimethyl-2-(triphenylsilyl)-7-[4-(triphenylsilyl)phenyl]-9H-fluorene (compound 4) as the host material with the green phosphorescence dopant bis[2-(1,1′,2′,1′′-terphen-3-yl)pyridinato-C,N]iridium(III) (acetylacetonate) showed the efficient green emission with an external quantum efficiency of 4.64%, a power efficiency of 7.2 lm/W and luminous efficiency of 16.6 cd/A at 20 mA/cm{sup 2}, respectively, with the Commission International de L’Eclairage chromaticity coordinates of (0.33, 0.59) at 8.0 V.

  19. EPR-study of reversible oxygenation process of coordination compounds of cobalt(II) with S-substituted N/sup 1/,N/sup 4/-di(salicylidene)-isothiosemicarbazides

    Energy Technology Data Exchange (ETDEWEB)

    Gerbeleu, N.V.; Revenko, M.D.; Rusu, V.G.; Shames, A.T.

    1987-09-01

    The reaction between molecular oxygen and coordination compounds of cobalt(II) with S-substituted N/sup 1/,N/sup 4/-di(salicylidene)isothiosemicarbazides in dimethyl sulfoxide solution was studied by the EPR method. It was found that paramagnetic monomeric adducts and diamagnetic ..mu..-peroxo-dimers are formed. The spin-Hamiltonian parameters of the EPR spectra of the initial cobalt complexes, as well as of the paramagnetic adducts were determined. The nature of the Co-O/sub 2/ bond is discussed.

  20. Decryptification of Acid Phosphatase in Arthrospores of Geotrichum Species Treated with Dimethyl Sulfoxide and Acetone

    Science.gov (United States)

    Cotter, David A.; Martel, Anita J.; MacDonald, Paul

    1975-01-01

    Decryptification of acid phosphatase in Geotrichum sp. arthrospores was accomplished using acetone or dimethyl sulfoxide treatment. Both dimethyl sulfoxide and acetone irreversibly destroyed the integrity of the spore membranes without solubilizing acid phosphatase. PMID:1167386

  1. Synthesis of anatoxin a via intramolecular cyclization of iminium salts

    International Nuclear Information System (INIS)

    Bates, H.A.; Rapoport, H.

    1979-01-01

    Anatoxin a (1) has been synthesized by exploiting intramolecular cyclization between an iminium salt and a nucleophilic carbon to construct the 9-azabicyclo[4.2.1]nonane ring system. Cyclization of malonate iminiumsalt 16 at alkaline pH afforded a low yield of bicyclic malonate 18 owing to an unfavorable equilibrium constant and lability of the iminium salt in base. In contrast, cyclization of ketoiminium salt 31 afforded a good yield of bicyclic ketone 34 in acidic methanol. Dihydropyrrolium salts 16 and 31 were generated quantitatively by decarbonylation of substituted N-methylprolines 15 and 30b, obtained by reduction of the corresponding pyrroles

  2. Chemistry of the Calceolaria Genus. Structural and Biological Aspects

    Directory of Open Access Journals (Sweden)

    Juan A. Garbarino

    2000-03-01

    Full Text Available Autochthonous species of the Calceolaria (Scrophulariaceae genus are studied. From their apolar extracts 55 new diterpenes of six skeleton types, naphtoquinones and flavonoids have been isolated. Among the different diterpenes malonic substitutions and bis-diterpenes in which both units are joined by a malonic acid unit stand out. Pimaranes present C-9 epimerisation and, consequently, H-9 has the same orientation as Me-20. From C.sessilis naphthoquinones with antichagasic activity have been isolated; and the biotransformation of 2α,19-dihydroxy-9-epi-entpimara-7,15-diene with Giberella fujikuroi produced 7 new diterpenes.

  3. Industrial Systems Biology of Saccharomyces cerevisiae Enables Novel Succinic Acid Cell Factory

    DEFF Research Database (Denmark)

    Otero, José Manuel; Cimini, Donatella; Patil, Kiran Raosaheb

    2013-01-01

    Saccharomyces cerevisiae is the most well characterized eukaryote, the preferred microbial cell factory for the largest industrial biotechnology product (bioethanol), and a robust commerically compatible scaffold to be exploitted for diverse chemical production. Succinic acid is a highly sought......-direction of carbon fluxes in S. cerevisiae, and hence show proof of concept that this is a potentially attractive cell factory for over-producing different platform chemicals....

  4. Measurement of (vapor + liquid) equilibrium for the systems {methanol + dimethyl carbonate} and {methanol + dimethyl carbonate + tetramethylammonium bicarbonate} at p = (34.43, 67.74) kPa

    International Nuclear Information System (INIS)

    Yang Changsheng; Zeng Hao; Yin Xia; Ma Shengyong; Sun Feizhong; Li Yafei; Li Jiao

    2012-01-01

    Highlights: ► VLE data for the binary system and the ternary system were measured. ► Methanol, dimethyl carbonate, and tetramethylammonium bicarbonate were studied. ► Isobaric experimental data were measured at p = (34.43, 67.74) kPa. ► VLE data of binary system were correlated with the Wilson, NRTL, and UNIQUAC models. ► The salt effect of TMAB on the VLE of {methanol + DMC} system was investigated. - Abstract: Isobaric (vapor + liquid) equilibrium (VLE) data for the binary system (methanol + dimethyl carbonate) and the ternary system (methanol + dimethyl carbonate + tetramethylammonium bicarbonate) have been measured at p = (34.43, 67.74) kPa using a modified Rose–Williams still. The experimental data for the binary system were well correlated by Wilson, NRTL, and UNIQUAC activity-coefficient models at the two reduced pressures. All the experimental results of the binary system passed the thermodynamic consistency test by the area test of Redlich–Kister and the point test of Van Ness et al. The experimental results of ternary system show that the salt tetramethylammonium bicarbonate has a salting-in effect on methanol. And this effect enhances when the salt concentration increases.

  5. Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae).

    Science.gov (United States)

    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.

  6. Natural 4-hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®).

    Science.gov (United States)

    Schwab, Wilfried

    2013-06-13

    4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field.

  7. Natural 4-Hydroxy-2,5-dimethyl-3(2H-furanone (Furaneol®

    Directory of Open Access Journals (Sweden)

    Wilfried Schwab

    2013-06-01

    Full Text Available 4-Hydroxy-2,5-dimethyl-3(2H-furanone (HDMF, furaneol® and its methyl ether 2,5-dimethyl-4-methoxy-3(2H-furanone (DMMF are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field.

  8. Diapause prevention effect of Bombyx mori by dimethyl sulfoxide.

    Directory of Open Access Journals (Sweden)

    Takayuki Yamamoto

    Full Text Available HCl treatment has been, for about 80 years, the primary method for the prevention of entry into embryonic diapauses of Bombyx mori. This is because no method is as effective as the HCl treatment. In this study, we discovered that dimethyl sulfoxide (DMSO prevented entry into the diapause of the silkworm, Bombyx mori. The effect of diapause prevention was 78% as a result of treatment with 100% DMSO concentration, and the effect was comparable to that of the HCl treatment. In contrast, in the case of non-diapause eggs, hatchability was decreased by DMSO in a concentration-dependent manner. The effect of DMSO was restricted within 24 hours after oviposition of diapause eggs, and the critical period was slightly shorter than the effective period of the HCl treatment. DMSO analogs, such as dimethyl formamide (DMF and dimethyl sulfide (DMS, did little preventive effect against the diapause. Furthermore, we also investigated the permeation effects of chemical compounds by DMSO. When treated with an inhibitor of protein kinase CK2 (CK2 dissolved in DMSO, the prevention rate of the diapause was less than 40%. This means that the inhibition effect by the CK2 inhibitor was the inhibition of embryonic development after diapause prevention by DMSO. These data suggest that DMSO has the effects of preventing from entering into the diapause and permeation of chemicals into diapause eggs.

  9. Formation and stability of Vitamin E enriched nanoemulsions stabilized by Octenyl Succinic Anhydride modified starch

    Science.gov (United States)

    Vitamin E (VE) is highly susceptible to autoxidation; therefore, it requires systems to encapsulate and protect it from autoxidation.In this study,we developed VE delivery systems, which were stabilized by Capsul® (MS), a starch modified with octenyl succinic anhydride. Influences of interfacial ten...

  10. Bagasse hydrolyzates from Agave tequilana as substrates for succinic acid production by Actinobacillus succinogenes in batch and repeated batch reactor.

    Science.gov (United States)

    Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo

    2016-04-01

    The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh. Copyright © 2016. Published by Elsevier Ltd.

  11. Determination of thermodynamic parameters for enolization reaction of malonic and metylmalonic acids by using quartz crystal microbalance

    Directory of Open Access Journals (Sweden)

    Minoru Yoshimoto

    2016-06-01

    Full Text Available We investigated the process of a bromination reaction of malonic acid and methylmalonic acid in the Belousov-Zhabotinsky reaction by using a quartz crystal microbalance (QCM. The process involves an enolization reaction as a rate-determining step. We found that, in the step, the variation of Br2 concentration induced an exactly quantitative shift of a resonant frequency of the QCM, based on the change of the surface mass on the QCM and the solution viscosity and density. This new finding enabled us to estimate the reaction rate constants and the thermodynamic parameters of the enolization reaction due to a QCM measurement. The values measured by the QCM were in good agreement with those measured by a UV-spectrophotometer. As a result, we succeeded to develop a new measurement method of a nonlinear chemical reaction.

  12. Synthesis and Conformational Assignment of N-(E-Stilbenyloxymethylenecarbonyl-Substituted Hydrazones of Acetone and o-(m- and p- Chloro- (nitro- benzaldehydes by Means of and NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Przemysław Patorski

    2013-01-01

    Full Text Available Eighteen new N-(E-stilbenyloxyalkylcarbonyl-substituted hydrazones of ortho- (meta- and para- chloro- (nitro- benzaldehydes 1–18 and two analogous hydrazones of acetone 19-20 were prepared. The stereochemical behavior of 1–18 in dimethyl-d6 sulfoxide solution has been studied by NMR and NMR techniques, using spectral data of 19 and 20 as supporting material. The E-geometrical isomers and cis-/trans-amide conformers have been found for these hydrazones. Energy barriers of isomers are reported.

  13. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    Energy Technology Data Exchange (ETDEWEB)

    Dimov, V.; Green, K.; Bygdeman, M.; Konishi, Y.; Imaki, K.; Hayashi, M.

    1983-02-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2.

  14. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    International Nuclear Information System (INIS)

    Dimov, V.; Green, K.; Bygdeman, M.; Konishi, Y.; Imaki, K.; Hayashi, M.

    1983-01-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2

  15. Variability in abundance and fluxes of dimethyl sulphide in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; DileepKumar, M.

    , 285-300 pp. Dacey, J.W.H. and S.G. Wakeham, 1986. Oceanic dimethyl sulfide: production during zooplankton grazing on phytoplankton. Science, 233, 1314-1316. Dickson, D.M., R.G. Wyn Jones and J. Davenport, 1980. Study-state osmotic adaptation.... Seasonal and short-term variability in dimethyl sulfide, sulfur dioxide and biogenic sulfur and sea salt aerosol particles in the arctic marine boundary layer during summer and autumn. Tellus, 48B, 272-299. Liss P.S., G. Malin and S.M. Turner, 1993...

  16. Succinate Functionalization of Hyperbranched Polyglycerol-Coated Magnetic Nanoparticles as a Draw Solute During Forward Osmosis.

    Science.gov (United States)

    Yang, Hee-Man; Choi, Hye Min; Jang, Sung-Chan; Han, Myeong Jin; Seo, Bum-Kyoung; Moon, Jei-Kwon; Lee, Kune-Woo

    2015-10-01

    Hyperbranched polyglycerol-coated magnetic nanoparticles (SHPG-MNPs) were functionalized with succinate groups to form a draw solute for use in a forward osmosis (FO). After the one-step synthesis of hyperbranched polyglycerol-coated magnetic nanoparticles (HPG-MNPs), the polyglycerol groups on the surfaces of the HPG-MNPs were functionalized with succinic anhydride moieties. The resulting SHPG-MNPs showed no change of size and magnetic property compared with HPG-MNPs and displayed excellent dispersibility in water up to the concentration of 400 g/L. SHPG-MNPs solution showed higher osmotic pressure than that of HPG-MNPs solution due to the presence of surface carboxyl groups in SHPG-MNPs and could draw water from a feed solution across an FO membrane without any reverse draw solute leakage during FO process. Moreover, the water flux remained nearly constant over several SHPG-MNP darw solute regeneration cycles applied to the ultrafiltration (UF) process. The SHPG-MNPs demonstrate strong potential for use as a draw solute in FO processes.

  17. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety asp...

  18. Two Approaches to the Synthesis of Dimethyl Fumarate That Demonstrate Fundamental Principles of Organic Chemistry

    Science.gov (United States)

    Love, Brian E.; Bennett, Lisa J.

    2017-01-01

    Two experiments are described which lead to the preparation of dimethyl fumarate, a compound currently used in the treatment of multiple sclerosis. Preparation of a compound with "real-world" applications is believed to increase student interest in the experiment. One experiment involves the isomerization of dimethyl maleate to the…

  19. Expression, purification, crystallization and preliminary X-ray analysis of a novel N-substituted branched-chain l-amino-acid dioxygenase from Burkholderia ambifaria AMMD

    International Nuclear Information System (INIS)

    Qin, Hui-Min; Miyakawa, Takuya; Nakamura, Akira; Xue, You-Lin; Kawashima, Takashi; Kasahara, Takuya; Hibi, Makoto; Ogawa, Jun; Tanokura, Masaru

    2012-01-01

    Diffraction data were collected to a limiting resolution of 2.4 Å from a crystal of selenomethionyl-labelled SadA, an l-amino-acid dioxygenase. Ferrous ion- and α-ketoglutarate-dependent dioxygenase from Burkholderia ambifaria AMMD (SadA) catalyzes the C3-hydroxylation of N-substituted branched-chain l-amino acids, especially N-succinyl-l-leucine, coupled to the conversion of α-ketoglutarate to succinate and CO 2 . SadA was expressed in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion method at 293 K. Crystals of selenomethionine-substituted SadA were obtained using a reservoir solution containing PEG 3000 as the precipitant at pH 9.5 and diffracted X-rays to 2.4 Å resolution. The crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 49.3, b = 70.9, c = 148.2 Å. The calculated Matthews coefficient (V M = 2.1 Å 3 Da −1 , 41% solvent content) suggested that the crystal contains two molecules per asymmetric unit

  20. Effect of denaturants on the speciation of uranium(VI) complexes of malonic acid in micellar media

    International Nuclear Information System (INIS)

    Sailaja, B.B.V.; Kebede, Tesfahun; Nageswara Rao, G.; Prasada Rao, M.S.

    2001-01-01

    A computer assisted investigation has been made on the nature of complexes of uranium(VI) with malonic acid. The formation constants have been determined experimentally by monitoring hydrogen ion concentration. The distribution of the metal ion amongst the complexes formed with the above carboxylic acid has also been computed. The formation constants have been refined with the computer program, MINIQUAD75 using the primary alkalimetric data. The predominant complexes formed are UO 2 (H 2 C 3 O 4 ) 2 ) 2- , UO 2 (H 2 C 3 O 4 ) and UO 2 (H 2 C 3 O 4 )(H 2 C 3 O 4 H) - . The distribution pattern of different species varies with the relative concentrations of the metal ion and the ligand. The variation of stability with surfactant concentrations is found to be the cumulative effect of various factors like electrostatic interactions. dilution effect and competition for hydrogen ion associated with the nature of micelles. (author)

  1. Vapor phase carbonylation of dimethyl ether and methyl acetate with supported transition metal catalysts

    International Nuclear Information System (INIS)

    Shikada, T.; Fujimoto, K.; Tominaga, H.O.

    1986-01-01

    The synthesis of acetic acid (AcOH) from methanol (MeOH) and carbon monoxide has been performed industrially in the liquid phase using a rhodium complex catalyst and an iodide promoter. The selectivity to AcOH is more than 99% under mild conditions (175 0 C, 28 atm). The homogeneous rhodium catalyst has been also effective for the synthesis of acetic anhydride (Ac 2 O) by carbonylation of dimethyl ether (DME) or methyl acetate (AcOMe). However, rhodium is one of the most expensive metals and its proved reserves are quite limited. It is highly desired, therefore, to develop a new catalyst as a substitute for rhodium. The authors have already reported that nickel supported on active carbon exhibits an excellent activity for the vapor phase carbonylation of MeOh in the presence of iodide promoter and under moderately pressurized conditions. In addition, corrosive attack on reactors by iodide compounds is expected to be negligible in the vapor phase system. In the present work, vapor phase carbonylation of DME and AcOMe on nickel-active carbon (Ni/A.C.) and molybdenum-active carbon (Mo/A.C.) catalysts was studied

  2. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. DEBABRATA NANDI. Articles written in Journal of Chemical Sciences. Volume 128 Issue 8 August 2016 pp 1327-1335 Regular Article. Substitution reactions of [Pd(bipy)(malonate)] explored with a different set of ligands: Kinetic and mechanistic interpretation in aqueous ...

  3. 40 CFR 721.10055 - 1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts.

    Science.gov (United States)

    2010-07-01

    ...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. 721.10055 Section 721.10055 Protection of...-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. (a) Chemical substance and...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts (PMN P-03-46; CAS No. 136504-87-5) is subject to...

  4. A Preliminary Study Of The Effect Of Some Pressurising Gasses On The Viscosity Of Dimethyl Ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen

    2006-01-01

    -micro glass viscometers, size 25, submerged completely in a constant temperature bath. A kinematic viscosity of 0,188 cSt  0,001 cSt @ 25 C, was found, consistent with the previous and initial result 0,186 cSt   0,002 cSt. Key words: Dimethyl Ether (DME), a clean substitute for diesel oil. DME viscosity......, of glass, has been used. No significant change of the efflux time was found for all the pressurising gasses, except for the gas CO2. A reduction of efflux times was found for the CO2 of about 9 %   0,6 %. The measurement accuracy for all these series was found for this very low viscosity fluid...... to be in the range 0,2 % up to more than 1 %. The previously reported viscosity of DME has been corrected for the surface tension effect. Viscosity determination was initially based on a direct comparison of efflux times of DME with efflux times of distilled water. Assuming an upper limit for the variation...

  5. Enhancement of Schizochytrium DHA synthesis by plasma mutagenesis aided with malonic acid and zeocin screening.

    Science.gov (United States)

    Zhao, Ben; Li, Yafei; Li, Changling; Yang, Hailin; Wang, Wu

    2018-03-01

    Schizochytrium sp. accumulates valuable polyunsaturated fatty acid (PUFA), such as docosahexaenoic acid (DHA). In order to increase DHA synthesis in this microorganism, physical or chemical mutagenesis aided with powerful screening methods are still preferable, as its DHA synthetic pathway has not yet been clearly defined for gene manipulation. To breed this agglomerate microorganism of thick cell wall and rather large genome for increasing lipid content and DHA percentage, a novel strategy of atmospheric and room temperature plasma (ARTP) mutagenesis coupled with stepped malonic acid (MA) and zeocin resistance screening was developed. The final resulted mutant strain mz-17 was selected with 1.8-fold increased DHA production. Accompanied with supplementation of Fe 2+ in shake flask cultivation, DHA production of 14.0 g/L on average was achieved. This work suggests that ARTP mutation combined with stepped MA and zeocin resistance screening is an efficient method of breeding Schizochytrium sp. of high DHA production, and might be applied on other microorganisms for obtaining higher desired PUFA products.

  6. [Role of ATP-sensitive potassium channel activators in liver mitochondrial function in rats with different resistance to hypoxia].

    Science.gov (United States)

    Tkachenko, H M; Kurhaliuk, N M; Vovkanych, L S

    2003-01-01

    Effects of ATP-sensitive potassium (KATP) channels opener pinacidil (0.06 mg/kg) and inhibitor glibenclamide (1 mg/kg) in rats with different resistance to hypoxia on indices of ADP-stimulation of mitochondrial respiration by Chance, calcium capacity and processes of lipid peroxidation in liver has been investigated. We used next substrates of oxidation: 0.35 mM succinate, 1 mM alpha-ketoglutarate. Additional analyses contain the next inhibitors: mitochondrial fermentative complex I-10 mkM rotenone, succinate dehydrogenase 2 mM malonic acid. It was shown that effects of pinacidil induced the increasing of oxidative phosporylation efficacy and ATP synthesis together with lowering of calcium capacity in rats with low resistance to hypoxia. Effects of pinacidil were leveled by glibenclamide. These changes are connected with the increasing of respiratory rate, calcium overload and intensification of lipid peroxidation processes. A conclusion was made about protective effect of pinacidil on mitochondrial functioning by economization of oxygen-dependent processes, adaptive potentialities of organisms with low resistance to hypoxia being increased.

  7. Influence of Ca/Mg ratio on phytoextraction properties of Salix viminalis. II. Secretion of low molecular weight organic acids to the rhizosphere.

    Science.gov (United States)

    Magdziak, Z; Kozlowska, M; Kaczmarek, Z; Mleczek, M; Chadzinikolau, T; Drzewiecka, K; Golinski, P

    2011-01-01

    A hydroponic experiment in a phytotron was performed to investigate the effect of two different Ca/Mg ratios (4:1 and 1:10) and trace element ions (Cd, Cu, Pb and Zn) in solution on the efficiency of low molecular weight organic acid (LMWOA) formation in Salix viminalis rhizosphere. Depending on the Ca/Mg ratio and presence of selected trace elements at 0.5mM concentration, the amount and kind of LMWOAs in the rhizosphere were significantly affected. In physiological 4:1 Ca/Mg ratio the following complex of acids was observed: malonic (Pb, Zn), citric, lactic, maleic and succinic (Zn) acids. Under 1:10 Ca/Mg ratio, citric (Cd, Zn), maleic and succinic (Cd, Cu, Pb, Zn) acids were seen. Additionally, high accumulation of zinc and copper in all systems was observed, with the exception of those where one of the metals was at higher concentration. Summing up, the results indicate a significant role of LMWOAs in Salix phytoremediation abilities. Both effects can be modulated depending on the mutual Ca/Mg ratio. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Fermentation characteristics in conversion of organic acids obtained by oxidation of low-rank coals to poly({beta}-hydroxybutyrate) using A. eutrophus cells with some analysis on metabolic flux distribution; Kattan no ekisosanka de erareru yukisan wo suiso saikin wo riyoshite pori {beta}-hidorokishi rakusan (PHB) ni henkansaseru tameno baiyo kogakuteki kento to taisha ryusoku bunpu shisutemu kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, Shoko.; Shin, Huidong.; Shimizu, Kazuyuki. [Kyushu Institute of Technology, Fukuoka (Japan). Department of Biochemical engineering and science; Mae, Kazuhiro.; Miura, Koichi. [Kyoto University, Kyoto (Japan). Department of Chemical Engineering

    1999-03-10

    Fermentation characteristics are investigated for the conversion of glycolate, acetate, formate, and malonate obtained by the oxidation of low-rank coals to poly ({beta}-hydrox butyrate) (PHB) using A. eutrophus cells. Based on the cultivation experiments using one of the organic acids as a sole carbon source, it is found that acetate is the most effectively converted to PHB. When mixed organic acids are used, formate is preferentially consumed, followed by acetate, and finally glycolate. Although malate can not be utilized, it is implied that it might change the pathway flux distributions based on the metabolic flux analysis. Namely, it shows competitive inhibition to succinate dehydrogenase so that its addition during fermentation results in flux reduction from succinate to maleic acid as well as glyoxylate flux and gluconeogenesis flux. It is also found that NADPH generated from isocitrate is preferentially utilized for the reaction from {alpha}-ketoglutarate to glutamate when NH{sub 3} concentration is high, while it is eventually used for the PHB production from acetoacetyl CoA as NH{sub 3} concentration decreases. (author)

  9. The impact of nanoclay on the crystal growth kinetics and morphology of biodegradable poly(ethylene succinate) composite

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2012-07-01

    Full Text Available The impact of nanoclay on the isothermal crystal growth kinetics and morphology of biodegradable poly(ethylene succinate) (PES) is reported. A PES composite (PESNC) containing 5 wt% organically modified montmorillonite, was prepared via solvent...

  10. Preparation of novel trifluoroacetylketene O,N-acetals and trifluoromethyl-containing S,S-sulfoximido N-substituted heterocycles

    Energy Technology Data Exchange (ETDEWEB)

    Bonacorso, Helio G.; Vezzosi, Renata P.; Rodrigues, Isadora R.; Drekener, Roberta L.; Porte, Liliane M. F.; Flores, Alex F.C.; Zanatta, Nilo; Martins, Marcos A.P. [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Quimica], e-mail: heliogb@base.ufsm.br

    2009-07-01

    Two new trifluoroacetylketene O,N-acetals [CF{sub 3}C(O)CH=C(OEt)(NS(O)R{sub 2}), where R = CH{sub 3}, Ph] derived from the reaction of 4,4-diethoxy-1,1,1-trifluorobut-3-en-2-one [CF{sub 3}C(O) CH=C(OEt){sub 2}] with S,S-dimethyl- and S-methyl-S-phenyl-sulfoximide [HN=S(O)R{sub 2}], in the presence of triethylamine, have been obtained, in 60-72% yields, and applied in the synthesis of S,S-dimethylsulfoximido-substituted pyrazoles, isoxazoles and pyrimidines, in 55-89% yields, from the reactions of 4-ethoxy-4-(S,S-dimethylsulfoximido)-1,1,1-trifluorobut-3-en-2-one with hydrazines, hydroxylamine hydrochloride and acetylguanidine. (author)

  11. The synergistic effects of 2,4-D dimethyl amine and propanil herbicides on weed population in rice agroecosystem

    International Nuclear Information System (INIS)

    Nashriyah Mat; Ramli Ishak; Sabri Junoh; Ismail Sahid

    2002-01-01

    Four treatments with the herbicides 2,4-D dimethyl amine and propanil were carried out in two consecutive rice planting seasons, to study the synergistic effect of 2,4-D dimethyl amine and propanil on rice weed populations at Pasir Panjang, the Northwest Selangor Project (PBLS), Projek Barat Laut Selangor) rice granary area. The treatments were control, 1x recommended rate (single dose), 2x recommended rate (double dose) of 2,4-D dimethyl amine and farmer practice. In all plots, propanil herbicide was applied at similar rate. Among the ecological indices measured were Simpson Index of diversity and importance (I.V.). A total number of 19 weed species was identified and the most common important weed was Najas graminae Del. The second most commonly found important weed was Scirpus lateriflorus Gmel. Other important weeds frequently found were Echinochloa crus-galli (L.) Beauv. and Fimbristylis miliacea (L.) Vahl. In the rice agroecosystem, species diversity of weeds was affected but total weed biomass was not affected synergistically by the mixture of 2,4-D dimethyl amine and propanil. The negative synergistic effect of 2,4-D dimethyl amine and propanil was to increase the total biomass of Scirpus lateriflorus, at 2x recommended dose rate of 2,4-D dimethyl amine. (Author)

  12. The upper and lower limits of the mechanistic stoichiometry of mitochondrial oxidative phosphorylation. Stoichiometry of oxidative phosphorylation.

    Science.gov (United States)

    Beavis, A D; Lehninger, A L

    1986-07-15

    Determination of the intrinsic or mechanistic P/O ratio of oxidative phosphorylation is difficult because of the unknown magnitude of leak fluxes. Applying a new approach developed to overcome this problem (see our preceding paper in this journal), the relationships between the rate of O2 uptake [( Jo)3], the net rate of phosphorylation (Jp), the P/O ratio, and the respiratory control ratio (RCR) have been determined in rat liver mitochondria when the rate of phosphorylation was systematically varied by three specific means. (a) When phosphorylation is titrated with carboxyatractyloside, linear relationships are observed between Jp and (Jo)3. These data indicate that the upper limit of the mechanistic P/O ratio is 1.80 for succinate and 2.90 for 3-hydroxybutyrate oxidation. (b) Titration with malonate or antimycin yields linear relationships between Jp and (Jo)3. These data give the lower limit of the mechanistic P/O ratio of 1.63 for succinate and 2.66 for 3-hydroxybutyrate oxidation. (c) Titration with a protonophore yields linear relationships between Jp, (Jo)3, and (Jo)4 and between P/O and 1/RCR. Extrapolation of the P/O ratio to 1/RCR = 0 yields P/O ratios of 1.75 for succinate and 2.73 for 3-hydroxybutyrate oxidation which must be equal to or greater than the mechanistic stoichiometry. When published values for the H+/O and H+/ATP ejection ratios are taken into consideration, these measurements suggest that the mechanistic P/O ratio is 1.75 for succinate oxidation and 2.75 for NADH oxidation.

  13. Citrate- and Succinate-Modified Carbonate Apatite Nanoparticles with Loaded Doxorubicin Exhibit Potent Anticancer Activity against Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sultana Mehbuba Hossain

    2018-03-01

    Full Text Available Biodegradable inorganic apatite-based particle complex is popular for its pH-sensitivity at the endosomal acidic environment to facilitate drug release following cellular uptake. Despite being a powerful anticancer drug, doxorubicin shows severe off-target effects and therefore would need a carrier for the highest effectiveness. We aimed to chemically modify carbonate apatite (CA with Krebs cycle intermediates, such as citrate and succinate in order to control the growth of the resultant particles to more efficiently carry and transport the anticancer drug into the cancer cells. Citrate- or succinate-modified CA particles were synthesized with different concentrations of sodium citrate or sodium succinate, respectively, in the absence or presence of doxorubicin. The drug loading efficiency of the particles and their cellular uptake were observed by quantifying fluorescence intensity. The average diameter and surface charge of the particles were determined using Zetasizer. Cell viability was assessed by MTT assay. Citrate-modified carbonate apatite (CMCA exhibited the highest (31.38% binding affinity for doxorubicin and promoted rapid cellular uptake of the drug, leading to the half-maximal inhibitory concentration 1000 times less than that of the free drug in MCF-7 cells. Hence, CMCA nanoparticles with greater surface area enhance cytotoxicity in different breast cancer cells by enabling higher loading and more efficient cellular uptake of the drug.

  14. Iodine-Catalyzed Isomerization of Dimethyl Muconate

    Energy Technology Data Exchange (ETDEWEB)

    Settle, Amy E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Berstis, Laura R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Shuting [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rorrer, Nicholas [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hu, Haiming [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Ryan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Crowley, Michael F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-12

    cis,cis-Muconic acid is a platform biobased chemical that can be upgraded to drop-in commodity and novel monomers. Among the possible drop-in products, dimethyl terephthalate can be synthesized via esterification, isomerization, Diels-Alder cycloaddition, and dehydrogenation. The isomerization of cis,cis-dimethyl muconate (ccDMM) to the trans,trans-form (ttDMM) can be catalyzed by iodine; however, studies have yet to address (i) the mechanism and reaction barriers unique to DMM, and (ii) the influence of solvent, potential for catalyst recycle, and recovery of high-purity ttDMM. To address this gap, we apply a joint computational and experimental approach to investigate iodine-catalyzed isomerization of DMM. Density functional theory calculations identified unique regiochemical considerations due to the large number of halogen-diene coordination schemes. Both transition state theory and experiments estimate significant barrier reductions with photodissociated iodine. Solvent selection was critical for rapid kinetics, likely due to solvent complexation with iodine. Under select conditions, ttDMM yields of 95% were achieved in <1 h with methanol, followed by high purity recovery (>98%) with crystallization. Lastly, post-reaction iodine can be recovered and recycled with minimal loss of activity. Overall, these findings provide new insight into the mechanism and conditions necessary for DMM isomerization with iodine to advance the state-of-the-art for biobased chemicals.

  15. Molecular distribution and compound-specific stable carbon isotopic composition of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls in PM2.5 from Beijing, China

    Science.gov (United States)

    Zhao, Wanyu; Kawamura, Kimitaka; Yue, Siyao; Wei, Lianfang; Ren, Hong; Yan, Yu; Kang, Mingjie; Li, Linjie; Ren, Lujie; Lai, Senchao; Li, Jie; Sun, Yele; Wang, Zifa; Fu, Pingqing

    2018-02-01

    This study investigates the seasonal variation, molecular distribution and stable carbon isotopic composition of diacids, oxocarboxylic acids and α-dicarbonyls to better understand the sources and formation processes of fine aerosols (PM2.5) in Beijing. The concentrations of total dicarboxylic acids varied from 110 to 2580 ng m-3, whereas oxoacids (9.50-353 ng m-3) and dicarbonyls (1.50-85.9 ng m-3) were less abundant. Oxalic acid was found to be the most abundant individual species, followed by succinic acid or occasionally by terephthalic acid (tPh), a plastic waste burning tracer. Ambient concentrations of phthalic acid (37.9 ± 27.3 ng m-3) and tPh (48.7 ± 51.1 ng m-3) were larger in winter than in other seasons, illustrating that fossil fuel combustion and plastic waste incineration contribute more to wintertime aerosols. The year-round mass concentration ratios of malonic acid to succinic acid (C3 / C4) were relatively low by comparison with those in other urban aerosols and remote marine aerosols. The values were less than or equal to unity in Beijing, implying that the degree of photochemical formation of diacids in Beijing is insignificant. Moreover, strong correlation coefficients of major oxocarboxylic acids and α-dicarbonyls with nss-K+ suggest that biomass burning contributes significantly to these organic acids and related precursors. The mean δ13C value of succinic acid is the highest among all species, with values of -17.1 ± 3.9 ‰ (winter) and -17.1 ± 2.0 ‰ (spring), while malonic acid is more enriched in 13C than others in autumn (-17.6 ± 4.6 ‰) and summer (-18.7 ± 4.0 ‰). The δ13C values of major species in Beijing aerosols are generally lower than those in the western North Pacific atmosphere, the downwind region, which indicates that stable carbon isotopic compositions of diacids depend on their precursor sources in Beijing. Therefore, our study demonstrates that in addition to photochemical oxidation, high abundances of diacids

  16. Acetate and succinate production in amoebae, helminths, diplomonads, trichomonads and trypanosomatids: common and diverse metabolic strategies used by parasitic lower eukaryotes.

    Science.gov (United States)

    Bringaud, F; Ebikeme, C; Boshart, M

    2010-08-01

    Parasites that often grow anaerobically in their hosts have adopted a fermentative strategy relying on the production of partially oxidized end products, including lactate, glycerol, ethanol, succinate and acetate. This review focuses on recent progress in understanding acetate production in protist parasites, such as amoebae, diplomonads, trichomonads, trypanosomatids and in the metazoan parasites helminths, as well as the succinate production pathway(s) present in some of them. We also describe the unconventional organisation of the tricarboxylic acid cycle associated with the fermentative strategy adopted by the procyclic trypanosomes, which may resemble the probable structure of the primordial TCA cycle in prokaryotes.

  17. Metabolic Effects of a Succinic Acid

    Directory of Open Access Journals (Sweden)

    B. N. Shakh

    2014-01-01

    Full Text Available The paper discusses promises for clinical use of substrate antihypoxants.Objective: to investigate the efficacy of succinate containing  substrate  antihypoxants  on  systemic  oxygen  consumption,  blood  buffer  capacity,  and  changes  in  the  mixed venous blood level of lactate when they are used in gravely sick patients and victims with marked metabolic posthypoxic disorders.Subjects and methods. The trial enrolled 30 patients and victims who had sustained an episode of severe hypoxia of mixed genesis, the severity of which was evaluated by the APACHE II scale and amounted to 23 to 30 scores with a 46 to 70.3% risk of death. The standard infusion program in this group involved the succinate-containing drug 1.5% reamberin solution  in  a  total  dose  of  800  ml.  A  comparison  group  included  15  patients  who  had  undergone  emergency  extensive surgery for abdominal diseases. 400 ml of 10% glucose solution was used as an infusion medium. Oxygen consumption (VO2ml/min and carbon dioxide production (VCO2ml/min were measured before infusion and monitored for 2 hours. Arterial blood gases and acid-base balance (ABB parameters and mixed venous blood lactate levels were examined. Measurements were made before and 30 minutes after the infusion of reamberin or glucose solution.Results. Infusion of 1.5% reamberin solution was followed by a significant increase in minute oxygen consumption from 281.5±21.2 to 310.4±24.4 ml/min. CO2 production declined (on average, from 223.3±6.5 to 206.5±7.59 ml/min. During infusion of 10% glucose solution, all the patients of the comparison group showed a rise in oxygen consumption from 303.6±33.86 to 443.13±32.1 ml/min, i.e. about 1.5-fold. VCO2 changed similarly. The intravenous infusion of 800 ml of 1.5% reamberin solution raised arterial blood buffer capacity, which was reflected by changes in pH, BE, and HCO3. There was a clear trend for lactate values to drop in the

  18. Carboxymethyl Cellulose (CMC) from Oil Palm Empty Fruit Bunch (OPEFB) in the new solvent Dimethyl Sulfoxide (DMSO)/Tetrabutylammonium Fluoride (TBAF)

    Science.gov (United States)

    Eliza, M. Y.; Shahruddin, M.; Noormaziah, J.; Rosli, W. D. Wan

    2015-06-01

    The surplus of Oil Palm is the most galore wastes in Malaysia because it produced about half of the world palm oil production, which contributes a major disposal problem Synthesis from an empty fruit bunch produced products such as Carboxymethyl Cellulose (CMC), could apply in diverse application such as for paper coating, food packaging and most recently, the potential as biomaterials has been revealed. In this study, CMC was prepared by firstly dissolved the bleached pulp from OPEFB in mixture solution of dimethyl sulfoxide(DMSO)/tetrabutylammonium fluoride (TBAF) without any prior chemical modification. It took only 30 minutes to fully dissolve at temperature 60°C before sodium hydroxide (NaOH) were added for activation and monochloroacetateas terrifying agent. The final product is appeared in white powder, which is then will be analyzedby FTIR analysis. FTIR results show peaks appeared at wavenumber between 1609 cm-1 to 1614 cm-1 proved the existence of carboxymethyl groups which substitute OH groups at anhydroglucose(AGU) unit. As a conclusion, mixture solution of DMSO/TBAF is the suitable solvent used for dissolved cellulose before modifying it into CMC with higher Degree of Substitution (DS). Furthermore, the dissolution of the OPEFB bleached pulp was easy, simple and at a faster rate without prior chemical modification at temperature as low as 60°C.

  19. Progesterone radioimmunoassay with the use of progesterone derivative substituted at 12α position

    International Nuclear Information System (INIS)

    Kula, E.; Stupnicka, R.

    1981-01-01

    A direct (non-extraction) radioimmunoassay method for progesterone determination in blood plasma has been presented. A new progesterone derivative substituted at 12α position was used as antigen for production of antibody. Cheap and easily accessible substrate -deoxycholic acid - was used as starting material for 9 step degradation procedure yielding 12α-hydroxy-progesterone. The latter compound was subsequently esterified with succinic anhydrine and conjugated with bovine serum albumin. The conjugate was then used for the immunization of rabbits to obtain immune antisera. After the detailed characterization, the obtained antibodies have been used for the determination of progesterone in human and cattle blood plasma. Transcortin present in samples used for the determinations was saturated with the excess of cortisol. The sensitivity of the method was found to be 5 pg in a sample, which corresponds to the concentration of about 0.25 ng/ml in blood plasma, in as much as the volume of plasma used for analysis was 20 ml. The within-series error was 7% when progesterone concentration in plasma samples was higher than 2.5 ng/ml. (author)

  20. Crystallization and degradation behaviors of poly(butylene succinate)/poly(Z-L-lysine) composites

    International Nuclear Information System (INIS)

    Tan, Licheng; Hu, Jun; Ye, Suwen; Wei, Junchao; Chen, Yiwang

    2014-01-01

    Highlights: • A new biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were successfully prepared through physical blend. • PZlys may greatly affected the crystallization behaviors of PBS without changing its crystalline structure. • The degradation speed of PBS may be greatly accelerated by introduction of PZlys in PBS matrix. - Abstract: A new type of biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were prepared. The crystallization behaviors were investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM) and the results showed that PZlys can restrict the crystallization of PBS, the crystallization speed of PBS/PZlys were slower than that of PBS, and the crystallization degree of the composites were smaller than that of PBS. However, the WAXD results showed that the incorporation of PZlys did not change the crystalline structure of PBS. The in vitro degradation experiments demonstrated that the degradation speed of the composites were faster than that of PBS. Moreover, the mechanical properties of the composites showed that the composites with a proper composition (for example, 80/20) can keep the mechanical properties of PBS without evident difference, which implied that the composites might be potentially useful as biodegradable materials

  1. Fixation of carbon dioxide into dimethyl carbonate over ...

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

  2. Development of a validated HPLC method for the quantitative determination of trelagliptin succinate and its related substances in pharmaceutical dosage forms.

    Science.gov (United States)

    Luo, Zhiqiang; Chen, Xinjing; Wang, Guopeng; Du, Zhibo; Ma, Xiaoyun; Wang, Hao; Yu, Guohua; Liu, Aoxue; Li, Mengwei; Peng, Wei; Liu, Yang

    2018-01-01

    Trelagliptin succinate is a dipeptidyl peptidase IV (DPP-4) inhibitor which is used as a new long-acting drug for once-weekly treatment of type 2 diabetes mellitus (DM). In the present study, a rapid, sensitive and accurate high-performance liquid chromatography (HPLC) method was developed and validated for separation and determination of trelagliptin succinate and its eight potential process-related impurities. The chromatographic separation was achieved on a Waters Xselect CSH™ C 18 (250mm×4.6mm, 5.0μm) column. The mobile phases comprised of 0.05% trifluoroacetic acid in water as well as acetonitrile containing 0.05% trifluoroacetic acid. The compounds of interest were monitored at 224nm and 275nm. The stability-indicating capability of this method was evaluated by performing stress test studies. Trelagliptin succinate was found to degrade significantly in acid, base, oxidative and thermal stress conditions and only stable in photolytic degradation condition. The degradation products were well resolved from the main peak and its impurities. In addition, the major degradation impurities formed under acid, base, oxidative and thermal stress conditions were characterized by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). The method was validated to fulfill International Conference on Harmonisation (ICH) requirements and this validation included specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and robustness. The developed method in this study could be applied for routine quality control analysis of trelagliptin succinate tablets, since there is no official monograph. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. INFLUENCE OF METOPROLOL SUCCINATE ON REGULATORY AND ADAPTIVE STATUS OF PATIENTS WITH CHRONIC HEART FAILURE FUNCTIONAL CLASS I. RESULTS OF NOT COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    V. G. Tregubov

    2011-01-01

    Full Text Available Aim. To estimate metoprolol succinate effect on regulatory and adaptive status (RAS of patients with сhronic heart failure (CHF functional class (FC I and arterial hypertension (HT I-II stages. Material and methods. 51 patients with CHF FC I and HT I-II stage, (30 men and 21 women aged 52.6±1.4 yeas. Cardio-respiratory synchronism (CRS test, 6-minute walking test, tread-mill burden test with registration of maximal oxygen consumption, 24-hour blood pressure monitoring, echocardiography and determination of N-terminal pro-brain natriuretic peptide (NT-proBNP blood level were performed initially and after 6 months of therapy with metoprolol succinate (dose 78.1±5.7 mg/day in sustained-release presentation. Results. Metoprolol succinate therapy had no significant effect on RAS (there was no unidirectional dynamics of the basic CRS test parameters: a range of synchronization decreased significantly from 8.8±0.4 to 7.2±0.6 сardio-respiratory cycles per minute (in 18%; р<0.05, and duration of CRS development on the minimal boundary from 18.8±2.2 to 14.3±1.2 сardiocycles (in 24%; р<0,05; RAS index considerably did not change, myocardium structure, exercise tolerance and neuro-humoral activity. Metoprolol therapy only moderately improved left ventricle diastolic function. Conclusion. Metoprolol succinate therapy has no significant effect on RAS of patients with CHF FC I and HT I-II stages.

  4. Recommended vapor pressures for thiophene, sulfolane, and dimethyl sulfoxide

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.; Růžička, M.

    2011-01-01

    Roč. 303, č. 2 (2011), s. 205-216 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : thiophene sulfolane * dimethyl sulfoxide * vapor pressure * heat capacity * vaporization enthalpy * recommended vapor pressure equation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

  5. Radiation-induced alterations in succinate dehydrogenase activity in the muscle of pigeon

    International Nuclear Information System (INIS)

    Gadhia, P.K.; Shah, V.C.

    1983-01-01

    The histochemical changes in succinate dehydrogenase were investigated in pectoralis major muscle of pigeon exposed to sub-lethal dose (400 rad) of γ-irradiation. Biochemical study was also carried out after 200, 300 and 400 rad of irradiation. In the present study the overall decrease in enzyme activity could be due to the structural and/or functional damage to mitochondria after treatment of pigeon to different sub-lethal doses of γ-irradiation. The significance of these results has been discussed with special reference to oxidative metabolism. (author)

  6. Fate of aliphatic compounds in nitric acid processing solutions

    International Nuclear Information System (INIS)

    Clark, W.E.; Howerton, W.B.

    1975-01-01

    The reaction of hyperazeotropic iodic acid-saturated nitric acid with short chain aliphatic iodides, nitrates, and acids was studied in order to determine the conditions for complete removal of organic materials from nitric acid systems. The aliphatic iodides are converted to the nitrates and the nitrates in strong HNO 3 are extensively converted into CO 2 and acids. The aliphatic acids are rather stable; acetic acid was unattacked by boiling in 20M HNO 3 and n-butyric acid was 80 percent unattacked. The dibasic acids oxalic and malonic are extensively attacked, but succinic acid is relatively stable. A wet oxidation method is successful in destroying acetic acid in 5 to 8M HNO 3 . (U.S.)

  7. Dissociation and homoconjugation equilibria of some acids and bases in N,N-dimethylformamide.

    Science.gov (United States)

    Roletto, E; Vanni, A

    1977-01-01

    The following monoprotic acids have been studied in N,N-dimethylformamide (DMF): p-toluenesulphonic acid; 2,6-dichlorobenzoic acid; 2,5-dichlorophenol; the anilinium ion; the N-methyl-anilinium ion. The first dissociation step of malonic and succinic acids has also been studied. Dissociation and homoconjugation constants have been determined potentiometrically, at 25 degrees , in buffer solutions containing either the acid and its tetraethylammonium salt or the base and its picrate. Homoconjugation equilibria between unchanged acid and univalent conjugate base have been found not only for benzoic acid and phenol derivatives, but also between undissociated diprotic carboxylic acids and the corresponding monoanions, which are strongly intramolecularly hydrogen-bonded. Results are discussed with reference to previously published values.

  8. Scale Up of Malonic Acid Fermentation Process: Cooperative Research and Development Final Report, CRADA Number CRD-16-612

    Energy Technology Data Exchange (ETDEWEB)

    Schell, Daniel J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-16

    The goal of this work is to use the large fermentation vessels in the National Renewable Energy Laboratory's (NREL) Integrated Biorefinery Research Facility (IBRF) to scale-up Lygos' biological-based process for producing malonic acid and to generate performance data. Initially, work at the 1 L scale validated successful transfer of Lygos' fermentation protocols to NREL using a glucose substrate. Outside of the scope of the CRADA with NREL, Lygos tested their process on lignocellulosic sugars produced by NREL at Lawrence Berkeley National Laboratory's (LBNL) Advanced Biofuels Process Development Unit (ABPDU). NREL produced these cellulosic sugar solutions from corn stover using a separate cellulose/hemicellulose process configuration. Finally, NREL performed fermentations using glucose in large fermentors (1,500- and 9,000-L vessels) to intermediate product and to demonstrate successful performance of Lygos' technology at larger scales.

  9. Footwear contact dermatitis from dimethyl fumarate.

    Science.gov (United States)

    Švecová, Danka; Šimaljakova, Maria; Doležalová, Anna

    2013-07-01

    Dimethyl fumarate (DMF) is an effective inhibitor of mold growth. In very low concentrations, DMF is a potent sensitizer that can cause severe allergic contact dermatitis (ACD). It has been identified as the agent responsible for furniture contact dermatitis in Europe. The aim of this study was to evaluate patients in Slovakia with footwear ACD associated with DMF, with regard to clinical manifestations, patch test results, and results of chemical analysis of their footwear. Nine patients with suspected footwear contact dermatitis underwent patch testing with the following allergens: samples of their own footwear, commercial DMF, the European baseline, shoe screening, textile and leather dye screening, and industrial biocides series. The results were recorded according to international guidelines. The content of DMF in footwear and anti-mold sachets was analyzed using gas chromatography and mass spectrometry. Acute ACD was observed in nine Caucasian female patients. All patients developed delayed sensitization, as demonstrated by positive patch testing using textile footwear lining. Seven patients were patch tested with 0.1% DMF, and all seven were positive. Chemical analysis of available footwear showed that DMF was present in very high concentrations (25-80 mg/Kg). Dimethyl fumarate is a new footwear allergen and was responsible for severe ACD in our patients. To avoid an increase in the number of cases, the already approved European preventive measures should be accepted and commonly employed. © 2013 The International Society of Dermatology.

  10. Linkage and radiation hybrid mapping of the porcine gene for subunit C of succinate dehydrogenase complex (SDHC)

    Czech Academy of Sciences Publication Activity Database

    Stratil, Antonín; Reiner, G.; Peelman, L. J.; Poucke, M.; Geldermann, H.

    2001-01-01

    Roč. 32, č. 2 (2001), s. 110-112 ISSN 0268-9146 R&D Projects: GA AV ČR KSK5052113; GA ČR GA523/00/0669 Keywords : succinate dehydrogenase complex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.020, year: 2001

  11. Formation of malonic dialdehyde and other 2-thiobarbituric-acid-active products in γ-radiolysis of DNA and DNA model substances in aqueous solution

    International Nuclear Information System (INIS)

    Langfinger, K.D.

    1984-01-01

    During radiation-induced DNA strand break, a product was observed which reacts positively with 2-thiobarbituric acid (TBA) to malonic dialdehyde (MDA) but is not a free MDA. The paper therefore discusses the formation of products during γ irradiation of DNA and DNA model substances which react positively with TBA to MDA. This reaction is highly sensitive but has low specificity, so that further analytical techniques were used for characterisation. These were: kinematic studies on chromophore formation using TBA, UV spectroscopy, and chromatography. The investigations comprised 1. Irradiation of sugars and polyalcohols. 2. Irradiation of nucleosides and nucleotides. 3. Irradiation of DNA. (orig./PW) [de

  12. A potentiometric study of (acid+base) equilibria in substituted 4-nitropyridine N-oxide systems in methanol and dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Gurzynski, Lukasz; Puszko, Aniela; Makowski, Mariusz; Chmurzynski, Lech

    2007-01-01

    The acid dissociation constants for cationic acids conjugated with 4-nitropyridine N-oxides have been determined using potentiometric titration method. The measurements in the systems of thirteen 4-nitropyridine N-oxide derivatives were carried out in the polar amphiprotic methanol (MeOH) and in the aprotic protophilic dimethyl sulfoxide (DMSO). Likewise as in the polar aprotic protophobic solvents (acetonitrile, acetone) it was found that in MeOH for all N-oxides studied the pK a values were readily determinable, whereas in DMSO the pK a values were hardly determinable or indeterminable by using the potentiometric method. In addition, just like in our previous investigations it was revealed that the sequence of the pK a values of the cationic acids in methanol is the same as in the water and the values are lower than those determined in acetonitrile and acetone. Also, it was found that the phenomenon of cationic homoconjugation equilibria was not present in the systems involving 4-nitropyridine N-oxide derivatives in both solvents used. Furthermore, protonation energies, ΔE prot , and Gibbs free enthalpies, ΔG prot , in vacuo have been compared with acid dissociation constants (expressed as pK a MeOH values) of the protonated N-oxides determined by potentiometric titration in methanol to establish a correlation between these magnitudes

  13. A potentiometric study of (acid+base) equilibria in substituted 4-nitropyridine N-oxide systems in methanol and dimethyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chemik.chem.univ.gda.pl

    2007-02-15

    The acid dissociation constants for cationic acids conjugated with 4-nitropyridine N-oxides have been determined using potentiometric titration method. The measurements in the systems of thirteen 4-nitropyridine N-oxide derivatives were carried out in the polar amphiprotic methanol (MeOH) and in the aprotic protophilic dimethyl sulfoxide (DMSO). Likewise as in the polar aprotic protophobic solvents (acetonitrile, acetone) it was found that in MeOH for all N-oxides studied the pK{sub a} values were readily determinable, whereas in DMSO the pK{sub a} values were hardly determinable or indeterminable by using the potentiometric method. In addition, just like in our previous investigations it was revealed that the sequence of the pK{sub a} values of the cationic acids in methanol is the same as in the water and the values are lower than those determined in acetonitrile and acetone. Also, it was found that the phenomenon of cationic homoconjugation equilibria was not present in the systems involving 4-nitropyridine N-oxide derivatives in both solvents used. Furthermore, protonation energies, {delta}E{sub prot}, and Gibbs free enthalpies, {delta}G{sub prot}, in vacuo have been compared with acid dissociation constants (expressed as pK{sub a}{sup MeOH} values) of the protonated N-oxides determined by potentiometric titration in methanol to establish a correlation between these magnitudes.

  14. Cyclopropanation of 5-(1-Bromo-2-phenyl-vinyl-3-methyl-4-nitro-isoxazoles under Phase Transfer Catalysis (PTC Conditions

    Directory of Open Access Journals (Sweden)

    Linda Piras

    2015-04-01

    Full Text Available Heavily substituted cyclopropane esters were prepared in high yields, complete diastereoselection and average (up to 58% enantioselectivity. The reaction described herein entailed reacting 4-nitro-5-bromostyrylisoxazoles, a class of powerful Michael acceptors with malonate esters under the catalysis of 5 mol% of a chincona derived phase-transfer catalyst.

  15. Alpha-Tocopheryl succinate induces cytostasis and apoptosis in osteosarcoma cells: the role of E2F1

    Czech Academy of Sciences Publication Activity Database

    Alleva, R.; Benassi, M.S.; Tomasetti, M.; Gellert, N.; Ponticelli, F.; Borghi, B.; Picci, P.; Neužil, Jiří

    2005-01-01

    Roč. 331, č. 4 (2005), s. 1515-1521 ISSN 0006-291X Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z5052915 Keywords : osteosarcoma * alpha-tocopheryl succinate * E2F1 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.000, year: 2005

  16. Evidence of redox imbalance in a patient with succinic semialdehyde dehydrogenase deficiency

    Directory of Open Access Journals (Sweden)

    Anna-Kaisa Niemi

    2014-01-01

    Full Text Available The pathophysiology of succinic semialdehyde dehydrogenase (SSADH deficiency is not completely understood. Oxidative stress, mitochondrial pathology, and low reduced glutathione levels have been demonstrated in mice, but no studies have been reported in humans. We report on a patient with SSADH deficiency in whom we found low levels of blood reduced glutathione (GSH, and elevations of dicarboxylic acids in urine, suggestive of possible redox imbalance and/or mitochondrial dysfunction. Thus, targeting the oxidative stress axis may be a potential therapeutic approach if our findings are confirmed in other patients.

  17. Theoretical and Experimental Studies of N,N-Dimethyl-N'-Picryl-4,4'-Stilbenediamine.

    Science.gov (United States)

    Papper, Vladislav; Wu, Yuanyuan; Kharlanov, Vladimir; Sukharaharja, Ayrine; Steele, Terry W J; Marks, Robert S

    2018-01-01

    N,N-dimethyl-N'-picryl-4,4'-stilbenediamine (DMPSDA) was prepared, purified and crystallised in a form of black lustrous crystals, and its absorption and fluorescence spectra were recorded in cyclohexane, acetonitrile and dimethyl sulfoxide. Non-emissive intramolecular charge transfer state (ICT) was clearly observed in this molecule in all three solvents. Theoretical calculations demonstrating a betaine electronic structure of the trinitrophenyl group in the ground state of the molecule and a charge transfer nature of the long wavelength transition S 0  → S 1 supported the experimental observations of the ICT formation in the molecule.

  18. 2-[(3,5-Dimethyl-1-phenyl-1H-pyrazol-4-ylmethylene]indane-1,3-dione

    Directory of Open Access Journals (Sweden)

    Abdullah M. Asiri

    2011-02-01

    Full Text Available The title compound 2-[(3,5-dimethyl-1-phenyl-1H-pyrazol-4-ylmethylene]-indane-1,3-dione (3 was synthesized in high yield by reaction of 3,5-dimethyl-1-phenyl-pyrazole-4-carbaldehyde and indane-1,3-dione in ethanol in the presence of pyridine. The structure of this new compound was confirmed by elemental analysis, IR, 1H NMR, 13C NMR and GC-MS spectral analysis.

  19. Locking of Turing patterns in the chlorine dioxide-iodine-malonic acid reaction with one-dimensional spatial periodic forcing.

    Science.gov (United States)

    Dolnik, Milos; Bánsági, Tamás; Ansari, Sama; Valent, Ivan; Epstein, Irving R

    2011-07-21

    We use the photosensitive chlorine dioxide-iodine-malonic acid reaction-diffusion system to study wavenumber locking of Turing patterns with spatial periodic forcing. Wavenumber-locked stripe patterns are the typical resonant structures that labyrinthine patterns exhibit in response to one-dimensional forcing by illumination when images of stripes are projected on a working medium. Our experimental results reveal that segmented oblique, hexagonal and rectangular patterns can also be obtained. However, these two-dimensional resonant structures only develop in a relatively narrow range of forcing parameters, where the unforced stripe pattern is in close proximity to the domain of hexagonal patterns. Numerical simulations based on a model that incorporates the forcing by illumination using an additive term reproduce well the experimental observations. These findings confirm that additive one-dimensional forcing can generate a two-dimensional resonant response. However, such a response is considerably less robust than the effect of multiplicative forcing. This journal is © the Owner Societies 2011

  20. Two transgenic mouse models for β-subunit components of succinate-CoA ligase yielding pleiotropic metabolic alterations

    DEFF Research Database (Denmark)

    Kacso, Gergely; Ravasz, Dora; Doczi, Judit

    2016-01-01

    Succinate-CoA ligase (SUCL) is a heterodimer enzyme composed of Suclg1 α-subunit and a substrate-specific Sucla2 or Suclg2 β-subunit yielding ATP or GTP, respectively. In humans, the deficiency of this enzyme leads to encephalomyopathy with or without methylmalonyl aciduria, in addition to result...

  1. Recent advances in the metabolic engineering of Corynebacterium glutamicum for the production of lactate and succinate from renewable resources.

    Science.gov (United States)

    Tsuge, Yota; Hasunuma, Tomohisa; Kondo, Akihiko

    2015-03-01

    Recent increasing attention to environmental issues and the shortage of oil resources have spurred political and industrial interest in the development of environmental friendly and cost-effective processes for the production of bio-based chemicals from renewable resources. Thus, microbial production of commercially important chemicals is viewed as a desirable way to replace current petrochemical production. Corynebacterium glutamicum, a Gram-positive soil bacterium, is one of the most important industrial microorganisms as a platform for the production of various amino acids. Recent research has explored the use of C. glutamicum as a potential cell factory for producing organic acids such as lactate and succinate, both of which are commercially important bulk chemicals. Here, we summarize current understanding in this field and recent metabolic engineering efforts to develop C. glutamicum strains that efficiently produce L- and D-lactate, and succinate from renewable resources.

  2. Dimethyl (E-2-(N-phenylacetamidobut-2-enedioate

    Directory of Open Access Journals (Sweden)

    Ting Bin Wen

    2011-01-01

    Full Text Available The title compound, C14H15NO5, was obtained from the reaction of acetanilide with dimethyl acetylenedicarboxylate in the presence of potassium carbonate. The C=C double bond adopts an E configuration and the geometry around the amide N atom is almost planar rather than pyramidal (mean deviation of 0.0032 Å from the C3N plane. The packing of the molecules in the crystal structure is stabilized by intermolecular C—H...O hydrogen bonds.

  3. Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

    CSIR Research Space (South Africa)

    Neppalli, R

    2014-01-01

    Full Text Available In this work, composite polystyrene/titanium dioxide (PS/TiO(sub2)) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior...

  4. The stability study of myristyl dimethyl amine oxide as an amphoteric ...

    African Journals Online (AJOL)

    The stability study of myristyl dimethyl amine oxide as an amphoteric surfactant in strong oxidant media containing 5 % m/m sodium hypochlorite through measurement of decomposing rate using high performance liquid chromatography and two phase titration.

  5. Mechanical and thermal properties of basalt fiber reinforced poly(butylene succinate) composites

    International Nuclear Information System (INIS)

    Zhang Yihe; Yu Chunxiao; Chu, Paul K.; Lv Fengzhu; Zhang Changan; Ji Junhui; Zhang Rui; Wang Heli

    2012-01-01

    Highlights: ► Novel basalt fiber-reinforced biodegradable poly(butylene succinate) composites have been successfully fabricated with various fiber loadings. ► The tensile and flexural properties of the PBS matrix resin are improved significantly by increasing the fiber loading in the composites. ► The impact strength of the BF/PBS composite decreases with the addition fibers primarily and increases with increasing fiber loading due to energy dissipation when the fibers are pulled out. ► Heat deflection temperature tests clearly show that the HDT of the basalt fiber reinforced PBS composites is significantly higher than the HDT of the PBS resin. - Abstract: Basalt fiber (BF) reinforced poly(butylene succinate) (PBS) composites have been fabricated with different fiber contents by a injection molding method and their tensile, flexural and impact properties, as well as thermal stability have been investigated. The tensile and flexural properties of the PBS matrix resin are improved markedly by increasing the fiber contents in the composites. The values are relatively higher than the natural fiber/PP systems reported earlier by other research groups. The heat deflection temperature (HDT) and Vicat softening temperature (VST) of the composites are significantly higher than those of the neat PBS resin. Scanning electron microscopy (SEM) conducted on the fracture surfaces of the composites reveals superior interfacial linkage between the basalt fibers and PBS matrix. The results suggest that the BF/PBS composites may be a potential candidate of PP or PP composites to manufacturing some daily commodities to solve the “white pollution” in environmental management.

  6. Preparation and characterization of malonic acid cross-linked chitosan and collagen 3D scaffolds: an approach on non-covalent interactions.

    Science.gov (United States)

    Mitra, Tapas; Sailakshmi, G; Gnanamani, A; Mandal, A B

    2012-05-01

    The present study emphasizes the influence of non-covalent interactions on the mechanical and thermal properties of the scaffolds of chitosan/collagen origin. Malonic acid (MA), a bifuncitonal diacid was chosen to offer non-covalent cross-linking. Three dimensional scaffolds was prepared using chitosan at 1.0% (w/v) and MA at 0.2% (w/v), similarly collagen 0.5% (w/v) and MA 0.2% (w/v) and characterized. Results on FT-IR, TGA, DSC, SEM and mechanical properties (tensile strength, stiffness, Young's modulus, etc.) assessment demonstrated the existence of non-covalent interaction between MA and chitosan/collagen, which offered flexibility and high strength to the scaffolds suitable for tissue engineering research. Studies using NIH 3T3 fibroblast cells suggested biocompatibility nature of the scaffolds. Docking simulation study further supports the intermolecular hydrogen bonding interactions between MA and chitosan/collagen.

  7. Mitochondrially targeted vitamin E succinate efficiently kills breast tumour-initiating cells in a complex II-dependent manner

    Czech Academy of Sciences Publication Activity Database

    Yan, B.; Stantic, M.; Zobalová, Renata; Bezawork-Geleta, A.; Stapelberg, M.; Stursa, J.; Prokopová, Kateřina; Dong, L.; Neužil, Jiří

    2015-01-01

    Roč. 15, č. 401 (2015) ISSN 1471-2407 R&D Projects: GA MZd NT14078; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Tumour-initiating cells * Mitochondrially targeted vitamin E succinate * Complex II Subject RIV: FD - Oncology ; Hematology Impact factor: 3.265, year: 2015

  8. PREPARATION AND PROPERTIES OF THREE NEUTRAL COPPER (I COMPLEXES BASED ON BIS[2-(DIPHENYLPHOSPHINOPHENYL]ETHER PHENYL] ETHER AND SUBSTITUTED IMIDAZOLE-2,9-DIMETHYL-1,10-PHENANTHROLINE

    Directory of Open Access Journals (Sweden)

    Xin Fang Liu

    2017-10-01

    Full Text Available With deprotonated 2-(4-nitro phenyl-, 2-(4-methyl phenyl-, and 2-(4-methoxy phenyl imidazoled-2,9-dimethyl-1,10-phenanthroline (NPIP, MPIP and MoPIP as nitrogen ligands, as well as bis[2-(diphenylphosphino phenyl]ether (DPEphos as phosphorus ligand, three Cu(I neutral complex has been synthesized and characterized by infrared spectroscopy (IR, elemental analysis and 1H NMR methods. TG-DTA shows that the complex begins to decompose when the temperature reached about 220 oC, indicating their high thermo-stability. The emission spectrum shows that the complexes exhibit yellow emission with a peak emission wavelength of 576, 585 and 596 nm under excitation of 287 nm in powder state.

  9. Direct synthesis of dimethyl carbonate from CO2 and methanol over ...

    Indian Academy of Sciences (India)

    The direct synthesis of dimethyl carbonate (DMC) from carbon dioxide (CO2) and methanol is ... Zirconia and ceria-based catalysts were most effective ... construction of a validation plant for dialkyl carbonates .... (mmol of MeOH consumed/2).

  10. Methyl 2-(2,2-dimethyl-3a,6a-dihydrofuro[3,2-d][1,3]dioxol-5-yl-4-oxo-4H-chromene-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Devadasan Velmurugan

    2013-08-01

    Full Text Available In the title molecule, C18H16O7, the dioxolane ring adopts an envelope conformation with the dimethyl-substituted C atom as the flap. The furan ring is almost coplanar with the pyran ring, with a dihedral angle of 1.04 (10° between the planes, and it makes a dihedral angle of 67.97 (11° with the mean plane of the dioxolane ring. The latter makes a dihedral angle of 67.15 (10° with the pyran ring. The O atom attached to the pyran ring deviates by −0.009 (1 Å. The crystal packing features C—H...O hydrogen bonds, forming a three-dimensional structure. The methoxycarbonyl atoms are disordered over two positions, with a refined occupancy ratio of 0.508 (18:0.492 (18.

  11. Mapping of Saccharomyces cerevisiae metabolites in fermenting wheat straight-dough reveals succinic acid as pH-determining factor.

    Science.gov (United States)

    Jayaram, Vinay B; Cuyvers, Sven; Lagrain, Bert; Verstrepen, Kevin J; Delcour, Jan A; Courtin, Christophe M

    2013-01-15

    Fermenting yeast does not merely cause dough leavening, but also contributes to the bread aroma and might alter dough rheology. Here, the yeast carbon metabolism was mapped during bread straight-dough fermentation. The concentration of most metabolites changed quasi linearly as a function of fermentation time. Ethanol and carbon dioxide concentrations reached up to 60 mmol/100g flour. Interestingly, high levels of glycerol (up to 10 mmol/100g flour) and succinic acid (up to 1.6 mmol/100g flour) were produced during dough fermentation. Further tests showed that, contrary to current belief, the pH decrease in fermenting dough is primarily caused by the production of succinic acid by the yeast instead of carbon dioxide dissolution or bacterial organic acids. Together, our results provide a comprehensive overview of metabolite production during dough fermentation and yield insight into the importance of some of these metabolites for dough properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Vibrational spectra and ab initio analysis of tert-butyl, trimethylsilyl, and trimethylgermyl derivatives of 3,3-dimethyl cyclopropene V. 3,3-Dimethyl-1-(trimethylgermyl)cyclopropene

    Science.gov (United States)

    De Maré, G. R.; Panchenko, Yu. N.; Abramenkov, A. V.; Baird, M. S.; Tverezovsky, V. V.; Nizovtsev, A. V.; Bolesov, I. G.

    2004-02-01

    3,3-Dimethyl-1-(trimethylgermyl)cyclopropene ( I) was synthesised using a standard procedure. The IR and Raman spectra of I in the liquid phase were measured. The molecular geometry of I was optimised completely at the HF/6-31G* level. The HF/6-31G*//HF/6-31G* force field was calculated and scaled using the set of scale factors transferred from those determined previously for scaling the theoretical force fields of 3,3-dimethylbutene-1 and 1-methyl-, 1,2-dimethyl-, and 3,3-dimethylcyclopropene. The assignments of the observed vibrational bands were performed using the theoretical frequencies calculated from the scaled HF/6-31G*//HF/6-31G* force field and the ab initio values of the IR intensities, Raman cross-sections and depolarisation ratios. The theoretical spectra are given. The completely optimised structural parameters of I and its vibrational frequencies are compared with corresponding data of related molecules.

  13. Dimethyl sulfoxide-inducible cytoplasmic factor involved in erythroid differentiation in mouse erythroleukemia (Friend) cells

    International Nuclear Information System (INIS)

    Watanabe, T.; Oishi, M.

    1987-01-01

    A previous report described an intracellular factor (differentiation-inducing factor I, or DIF-I) that seem to play a role in erythroid differentiation in mouse erythroleukemia (MEL) cells. The authors have detected another erythroid-inducing factor in cell-free extracts from dimethyl sulfoxide- or hexamethylenebis(acetamide)-treated MEL cells, which acts synergistically with DIF-I. The partially purified factor (termed DIF-II) triggered erythroid differentiation when introduced into undifferentiated MEL cells that had been potentiated by the induction of DIF-I. The activity in the extracts appeared in an inducible manner after addition of dimethyl sulfoxide or hexamethylenebis(acetamide), reached a maximum at 6 hr, and then rapidly decreased. The induction was inhibited by phorbol 12-myristate 13-acetate and also by cycloheximide. No induction was observed in a mutant MEL cell line defective in erythroid differentiation. These characteristics are consistent with the supposition that DIF-II is one of the putative dimethyl sulfoxide-inducible factors detected in previously reported cell-fusion and cytoplast-fusion experiments. The role of DIF-II in MEL-cell differentiation and in vitro differentiation in general is discussed

  14. Improved in situ saccharification of cellulose pretreated by dimethyl sulfoxide/ionic liquid using cellulase from a newly isolated Paenibacillus sp. LLZ1.

    Science.gov (United States)

    Hu, Dongxue; Ju, Xin; Li, Liangzhi; Hu, Cuiying; Yan, Lishi; Wu, Tianyun; Fu, Jiaolong; Qin, Ming

    2016-02-01

    A cellulase producing strain was newly isolated from soil samples and identified as Paenibacillus sp. LLZ1. A novel aqueous-dimethyl sulfoxide (DMSO)/1-ethyl-3-methylimidazolium diethyl phosphate ([Emin]DEP)-cellulase system was designed and optimized. In the pretreatment, DMSO was found to be a low-cost substitute of up to 70% ionic liquid to enhance the cellulose dissolution. In the enzymatic saccharification, the optimum pH and temperature of the Paenibacillus sp. LLZ1 cellulase were identified as 6.0 and 40°C, respectively. Under the optimized reaction condition, the conversion of microcrystalline cellulose and bagasse cellulose increased by 39.3% and 37.6%, compared with unpretreated cellulose. Compared to current methods of saccharification, this new approach has several advantages including lower operating temperature, milder pH, and less usage of ionic liquid, indicating a marked progress in environmental friendly hydrolysis of biomass-based materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Bid integrates intrinsic and extrinsic signaling in apoptosis induced by alpha-tocopheryl succinate in human gastric carcinoma cells

    Czech Academy of Sciences Publication Activity Database

    Zhao, Y.; Li, R.; Xia, W.; Neužil, Jiří; Lu, Y.; Zhang, H.; Zhao, X.; Zhang, X.; Sun, C.; Wu, K.

    2010-01-01

    Roč. 288, č. 1 (2010), s. 42-49 ISSN 0304-3835 R&D Projects: GA ČR(CZ) GA204/08/0811 Institutional research plan: CEZ:AV0Z50520701 Keywords : Alpha-tocopheryl succinate * signaling * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.864, year: 2010

  16. Effect of stretching on the mechanical properties in melt-spun poly(butylene succinate)/microfibrillated cellulose (MFC) nanocomposites.

    Science.gov (United States)

    Zhou, Mi; Fan, Mao; Zhao, Yongsheng; Jin, Tianxiang; Fu, Qiang

    2016-04-20

    In order to prepare poly(butylene succinate)/microfibrillated cellulose composites with high performance, in this work, microfibrillated cellulose (MFC) was first treated by acetylchloride with ball-milling to improve its interfacial compatibility with poly(butylene succinate) (PBS). Then melt stretching processing was adopted to further improve the dispersion and orientation of MFC in as-spun PBS fiber. And the effect of MFC on the crystalline structure and mechanical properties were systematically investigated for the melt-spun fibers prepared with two different draw ratios. The dispersion, alignment of the MFC and interfacial crystalline structure in the composite fibers are significantly influenced by the stretching force during the melt spinning. The possible formation of nanohybrid shish kebab (NHSK) superstructure where aligned MFC as shish and PBS lamellae as kebab has been suggested via SEM and SAXS in the composite fibers prepared at the high draw ratio. Large improvement in tensile strength has been realized at the high draw ratio due to the enhanced orientation and dispersion of MFC as well as the formation of NHSK. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. 99mtechnetium-dimercapto-succinic acid renal scanning and excretory urography in diagnosis of renal scars in children

    International Nuclear Information System (INIS)

    McLorie, G.A.; Aliabadi, H.; Churchill, B.M.; Ash, J.M.; Gilday, D.L.

    1989-01-01

    We compared the ability of excretory urography (without tomography) and 99mtechnetium-dimercapto-succinic acid renal scanning to detect renal scars in 32 children with primary vesicoureteral reflux. These children did not have hydronephrosis, renal failure or urinary tract obstruction. In all cases both studies were conducted within a 10-month period. The findings from both modalities were in agreement for 51 of the 64 renal units evaluated (80%). Evaluation of the excretory urogram indicated 6 cases of diffuse and 2 of focal scarring that were not detected by evaluation of the renal scan. The sensitivity of excretory urography to detect renal scars was 84% and the specificity was 83%. The 99mtechnetium-dimercapto-succinic acid renal scan showed 5 cases of focal renal scarring not detected by excretory urography. The sensitivity of the renal scan to detect renal scars was 77% and the specificity was 75%. We conclude that neither study alone could effectively replace the other for the detection of renal scars, and recommend that both be included in the initial evaluation and followup of patients with renal scars

  18. Simple, heart-smart substitutions

    Science.gov (United States)

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

  19. The H+/O ratio of proton translocation linked to the oxidation of succinate by mitochondria. Reply to a commentary.

    Science.gov (United States)

    Lehninger, A L; Reynafarje, B; Hendler, R W; Shrager, R I

    1985-11-18

    Costa, L.E., Reynafarje, B. and Lehninger, A.L. [(1984) J. Biol. Chem. 259, 4802-4811] have reported 'second-generation' measurements of the H+/O ratio approaching 8.0 for vectorial H+ translocation coupled to succinate oxidation by rat liver mitochondria. In a Commentary in this Journal [Krab, K., Soos, J. and Wikström, M. (1984) FEBS Lett. 178, 187-192] it was concluded that the measurements of Costa et al. significantly overestimated the true H+/O stoichiometry. It is shown here that the mathematical simulation on which Krab et al. based this claim is faulty and that data reported by Costa et al. had already excluded the criticism advanced by Krab et al. Also reported are new data, obtained under conditions in which the arguments of Krab et al. are irrelevant, which confirm that the H+/O ratio for succinate oxidation extrapolated to level flow is close to 8.

  20. Volatile Organic Sulfur Compounds of Environmental Interest: Dimethyl Sulfide and Methanethiol

    Science.gov (United States)

    Chasteen, Thomas G.; Bentley, Ronald

    2004-01-01

    Volatile organic sulfur compounds (VOSCs) have been assigned environmental roles in global warming, acid precipitation, and cloud formation where two important members dimethyl sulfide (CH3)2 S, DMS, and methanethiol, CH3SH, MT, of VOSC group are involved.

  1. Study on fluorescence properties of carbogenic nanoparticles and their application for the determination of ferrous succinate

    Energy Technology Data Exchange (ETDEWEB)

    Sun Wen [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); Du Yingxiang, E-mail: du_yingxiang@126.co [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Modern Chinese Medicines, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China); Wang Yunqing [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

    2010-08-15

    A new type of fluorescent nanomaterial named carbogenic nanoparticles (NPs) has drawn considerable attention recently. In this study, we adopted a direct and simple synthetic method to produce the carbogenic NPs and investigated the fluorescence properties of the as-prepared carbogenic NPs in detail. It was found that the fluorescence of carbogenic NPs was stable with the variance of environmental conditions such as pH, temperature and UV irradiation. More interestingly, we found carbogenic NPs exhibited high selectivity and sensitivity towards ferric ions. Under optimum conditions, a good linear relationship could be obtained between the fluorescence intensity and concentration of ferric ions in the range of 5.0x10{sup -5}-5.0x10{sup -4} mol L{sup -1}, and the limit of detection is 11.2 {mu}mol L{sup -1}. Based on the fluorescence quenching of carbogenic NPs, a rapid and specific quantitative method was proposed for the determination of ferrous succinate. The content of ferrous succinate in commercial tablets determined by the present method was agreed with the spectrophotometric method results and the reproducibility and the recovery of the proposed method were satisfactory.

  2. Application of ion chromatography to the determination of water-soluble inorganic and organic ions in atmospheric aerosols.

    Science.gov (United States)

    Yu, Xue-Chun; He, Ke-Bin; Ma, Yong-Liang; Yang, Fu-Mo; Duan, Feng-Kui; Zheng, Ai-Hua; Zhao, Cheng-Yi

    2004-01-01

    A simple, sensitive and convenient ion chromatography(IC) method was established for the simultaneous determination of twelve water-soluble inorganic anions(F- , Cl- , NO2(-), NO3(-), SO3(2-), SO4(2-) , PO4(3-)), and fifteen water-soluble organic ions(formate, acetate, MSA, oxalate, malonate, succinate, phthalates, etc.) in atmospheric aerosols. The linear concentrations ranged from 0.005 microg/m3 to 500 microg/m3 ( r = 0.999-0.9999). The relative standard deviation (RSD) were 0.43%-2.00% and the detection limits were from 2.7 ng/m3 to 88 ng/m3. The proposed method was successfully applied to the simultaneous determination of those inorganic ions and organic ions in PM2.5 of Beijing.

  3. Review of succinate dehydrogenase-deficient renal cell carcinoma with focus on clinical and pathobiological aspects

    Directory of Open Access Journals (Sweden)

    Naoto Kuroda

    2016-05-01

    Full Text Available Succinate dehydrogenase (SDH-deficient renal cell carcinoma (RCC was first identified in 2004 and has been integrated into the 2016 WHO classification of RCC. Succinate dehydrogenase (SDH is an enzyme complex composed of four protein subunits (SDHA, SDHB, SDHC and SDHD. The tumor which presents this enzyme mutation accounts for 0.05 to 0.2% of all renal carcinomas. Multiple tumors may occur in approximately 30% of affected patients. SDHB-deficient RCC is the most frequent, and the tumor histologically consists of cuboidal cells with eosinophilic cytoplasm, vacuolization, flocculent intracytoplasmic inclusion and indistinct cell borders. Ultrastructurally, the tumor contains abundant mitochondria. Immunohistochemically, tumor cells are positive for SDHA, but negative for SDHB in SDHB-, SDHC- and SDHD-deficient RCCs. However, SDHA-deficient RCC shows negativity for both SDHA and SDHB. In molecular genetic analyses, a germline mutation in the SDHB , SDHC or SDHD gene (in keeping with most patients having germline mutations in an SDH gene has been identified in patients with or without a family history of renal tumors, paraganglioma/pheochromocytoma or gastrointestinal stromal tumor. While most tumors are low grade, some tumors may behave in an aggressive fashion, particularly if they are high nuclear grade, and have coagulative necrosis or sarcomatoid differentiation.

  4. Discovering novel Alternaria solani succinate dehydrogenase inhibitors by in silico modeling and virtual screening strategies to combat early blight

    NARCIS (Netherlands)

    Iftikhar, Sehrish; Shahid, Ahmad A.; Halim, Sobia A.; Wolters, Pieter J.; Vleeshouwers, Vivianne G.A.A.; Khan, Ajmal; Al-Harrasi, Ahmed; Ahmad, Shahbaz

    2017-01-01

    Alternaria blight is an important foliage disease caused by Alternaria solani. The enzyme Succinate dehydrogenase (SDH) is a potential drug target because of its role in tricarboxylic acid cycle. Hence targeting Alternaria solani SDH enzyme could be efficient tool to design novel fungicides against

  5. Delayed dermal burns caused by dimethyl acetylenedicarboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Slovak, A J; Payne, A R

    1984-07-01

    A chemical operator handling dimethyl acetylenedicarboxylate (DMAD) developed delayed and pain-free burns on one of his feet 2 days after a supposed spillage of DMAD. The injuries were confirmed to be associated with DMAD by chemical analysis of the operator's safety boot and patch tests. DMAD easily penetrates some protective clothing and dilute solutions can still be hazardous: the toxic effect is compounded by being delayed and painless. The lachrymatory irritant properties of undiluted DMAD are not adequate warning of its presence or spillage in quantities sufficient to cause significant skin damage.

  6. Isotopomer profiling of Leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth.

    Science.gov (United States)

    Saunders, Eleanor C; Ng, William W; Chambers, Jennifer M; Ng, Milica; Naderer, Thomas; Krömer, Jens O; Likic, Vladimir A; McConville, Malcolm J

    2011-08-05

    Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various (13)C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and (13)C NMR. [U-(13)C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD(+) consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate (glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U-(13)C]aspartate and [U-(13)C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolism in Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions.

  7. Role of dimethyl fumarate in oxidative stress of multiple sclerosis: A review.

    Science.gov (United States)

    Suneetha, A; Raja Rajeswari, K

    2016-04-15

    Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS affecting both white and grey matter. Inflammation and oxidative stress are also thought to promote tissue damage in multiple sclerosis. Recent data point at an important role of anti-oxidative pathways for tissue protection in chronic MS, particularly involving the transcription factor nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2). Thus, novel therapeutics enhancing cellular resistance to free radicals could prove useful for MS treatment. Oxidative stress and anti-oxidative pathways are important players in MS pathophysiology and constitute a promising target for future MS therapy with dimethyl fumarate. The clinical utility of DMF in multiple sclerosis is being explored through phase III trials with BG-12, which is an oral therapeutic agent. Currently a wide research is going on to find out the exact mechanism of DMF, till date it is not clear. Based on strong signals of nephrotoxicity in non-humans and the theoretical risk of renal cell cancer from intracellular accumulation of fumarate, post-marketing study of a large population of patients will be necessary to fully assess the long-term safety of dimethyl fumarate. The current treatment goals are to shorten the duration and severity of relapses, prolong the time between relapses, and delay progression of disability. In this regard, dimethyl fumarate offers a promising alternative to orally administered fingolimod (GILENYA) or teriflunomide (AUBAGIO), which are currently marketed in the United States under FDA-mandated Risk Evaluation and Mitigation Strategy (REMS) programs because of serious safety concerns. More clinical experience with all three agents will be necessary to differentiate the tolerability of long-term therapy for patients diagnosed with multiple sclerosis. This write-up provides the detailed information of dimethyl fumarate in treating the neuro disease, multiple sclerosis and its mechanism involved via

  8. Structural and spectroscopic studies of 2,9-dimethyl-1,10 ...

    African Journals Online (AJOL)

    The crystal structures of the pronated ligand, 2,9-dimethyl-1,10-phenanthrolinium (DPH) cation with selected counter anions (chloride (1), triflate (2), and gold dicyanide (3)) are reported. The role of a hydrogen bond interaction in influencing the solid state p-p stacking found in all three compounds has been investigated.

  9. Qualitative and quantitative analysis of light hydrocarbons produced by radiation degradation of N, N-dimethyl hydroxylamine

    International Nuclear Information System (INIS)

    Wang Jinhua; Bao Borong; Wu Minghong; Sun Xilian; Zhang Xianye; Hu Jingxin; Ye Guoan

    2004-01-01

    This paper reports the qualitative and quantitative analysis of light hydrocarbons produced by radiation degradation of N, N-dimethyl hydroxylamine. These analyses were performed on the gas chromatograph, in which porous layer open tubular column coated with aluminum oxide and flame-ionization detector are used. For the doses between 10 and 1000 kGy, the light hydrocarbons produced by radiation degradation of N,N-dimethyl hydroxylamine are methane, ethane, ethene, propane, propene and n-butane. When the concentration of N,N-dimethyl hydroxylamine is 0.2 mol/L, the volume fraction of methane is (9.996-247.5) x 10 -6 , the volume fraction of ethane, propane and n-butane is lower and that of ethene and propene is much lower. With the increase of dose the volume fraction of methane is increased but the volume fraction of ethane, ethene, propane, propene and n-butane is not obviously changed. (authors)

  10. Molecular distribution and compound-specific stable carbon isotopic composition of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls in PM2.5 from Beijing, China

    Directory of Open Access Journals (Sweden)

    W. Zhao

    2018-02-01

    Full Text Available This study investigates the seasonal variation, molecular distribution and stable carbon isotopic composition of diacids, oxocarboxylic acids and α-dicarbonyls to better understand the sources and formation processes of fine aerosols (PM2.5 in Beijing. The concentrations of total dicarboxylic acids varied from 110 to 2580 ng m−3, whereas oxoacids (9.50–353 ng m−3 and dicarbonyls (1.50–85.9 ng m−3 were less abundant. Oxalic acid was found to be the most abundant individual species, followed by succinic acid or occasionally by terephthalic acid (tPh, a plastic waste burning tracer. Ambient concentrations of phthalic acid (37.9 ± 27.3 ng m−3 and tPh (48.7 ± 51.1 ng m−3 were larger in winter than in other seasons, illustrating that fossil fuel combustion and plastic waste incineration contribute more to wintertime aerosols. The year-round mass concentration ratios of malonic acid to succinic acid (C3 ∕ C4 were relatively low by comparison with those in other urban aerosols and remote marine aerosols. The values were less than or equal to unity in Beijing, implying that the degree of photochemical formation of diacids in Beijing is insignificant. Moreover, strong correlation coefficients of major oxocarboxylic acids and α-dicarbonyls with nss-K+ suggest that biomass burning contributes significantly to these organic acids and related precursors. The mean δ13C value of succinic acid is the highest among all species, with values of −17.1 ± 3.9 ‰ (winter and −17.1 ± 2.0 ‰ (spring, while malonic acid is more enriched in 13C than others in autumn (−17.6 ± 4.6 ‰ and summer (−18.7 ± 4.0 ‰. The δ13C values of major species in Beijing aerosols are generally lower than those in the western North Pacific atmosphere, the downwind region, which indicates that stable carbon isotopic compositions of diacids depend on their precursor sources in Beijing. Therefore, our

  11. Radioprotection by dimethyl sulfoxide on two biological system

    International Nuclear Information System (INIS)

    Bernardes, D.M.L.; Villavicencio, A.L.C.H.; Del Mastro, N.L.

    1990-01-01

    The effects of dimethyl sulfoxide treatment on two biological systems are examined: a) In vivo, the level of albinic mouse survive from IPEN, when irradiated with 9 Gy of 60 Co., 1 hour after the injection ip of DMSO 0,025M. b) In vivo, molecular level, when DMSO 1M, is added 10 min. before the irradiation with 25.000 Gy of 60 Co, from an aqueous solution of proteins from crystalline bovine. (C.G.C.) [pt

  12. Three-body dissociations: The photodissociation of dimethyl sulfoxide at 193 nm

    International Nuclear Information System (INIS)

    Blank, D.A.; North, S.W.; Stranges, D.

    1997-01-01

    When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH 3 SOCH 3 ) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH 3 intermediate prior to dissociation to define a stepwise dissociation: (1) CH 3 SOCH 3 → 2CH 3 + SO; (2a) CH 3 SOCH 3 → CH 3 + SOCH 3 ; and (2b) SOCH 3 → SO + CH 3 . Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH 3 and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 9.0.2.1. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH 3 intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2

  13. 4,8-bisallyl-2,6-dimethylnaphthalene-1,5-diyl diacetate

    DEFF Research Database (Denmark)

    Christensen, Jørn Bolstad; Sørensen, Jeanett N.; Schaumburg, Kjeld

    2014-01-01

    4,8-Diallyl-2,6-dimethylnaphthalene-1,5-diyl diacetate (1) which is a highly substituted naphthalene derivative has been synthesized in two steps starting from 2,6-dimethyl-1,5-naphthalenediol (3) using a modified Claisen-rearrangement.......4,8-Diallyl-2,6-dimethylnaphthalene-1,5-diyl diacetate (1) which is a highly substituted naphthalene derivative has been synthesized in two steps starting from 2,6-dimethyl-1,5-naphthalenediol (3) using a modified Claisen-rearrangement....

  14. Kinetics of periodate oxidation of tris -(4,4'-dimethyl-2,2'-bipyridine ...

    African Journals Online (AJOL)

    dimethyl-2,2'-bipyridine) iron(II) in acid medium was investigated. The complex undergoes extensive protonation in acid medium. Both protonated and the unprotonated species undergo electron transfer reaction with the active periodate species ...

  15. Total synthesis of (±)-antroquinonol d.

    Science.gov (United States)

    Sulake, Rohidas S; Jiang, Yan-Feng; Lin, Hsiao-Han; Chen, Chinpiao

    2014-11-21

    Total synthesis of (±)-antroquinonol D, which is isolated from very expensive and rarely found Antrodia camphorata and which has potential anticancer properties, was achieved from 4-methoxyphenol. In addition, a Michael addition to dimethoxy cyclohexadienones was studied. The main step involved chelation and substrate-controlled diastereoselective reduction of cyclohexenone and lactonization. Lactone synthesis facilitated the diastereoselective reduction of ketone, which help control the desired stereochemistry at the crucial stereogenic center in the natural product. Other key reactions in the synthesis involved a Michael addition of dimethyl malonate on cyclohexadienone, dihydroxylation, and Wittig olefination. A sesquiterpene side chain was synthesized through coupling with geranyl phenyl sulfide and Bouveault-Blanc reduction.

  16. Mitochondrially Targeted Vitamin E Succinate Modulates Expression of Mitochondrial DNA Transcripts and Mitochondrial Biogenesis

    Czech Academy of Sciences Publication Activity Database

    Truksa, Jaroslav; Dong, L.F.; Rohlena, Jakub; Stursa, J.; Vondrusová, Magdaléna; Goodwin, J.; Nguyen, M.; Klučková, Katarína; Rychtarčíková, Zuzana; Lettlová, Sandra; Spáčilová, Jana; Stapelberg, M.; Zoratti, M.; Neužil, Jiří

    2015-01-01

    Roč. 22, č. 11 (2015), s. 883-900 ISSN 1523-0864 R&D Projects: GA ČR GAP301/10/1937; GA AV ČR KAN200520703; GA ČR GAP305/12/1708; GA ČR GAP301/12/1851; GA MŠk(CZ) ED1.1.00/02.0109 Institutional research plan: CEZ:AV0Z50520701 Institutional support: RVO:86652036 Keywords : ALPHA-TOCOPHERYL SUCCINATE * ELECTRON-TRANSPORT CHAIN * RESPIRATORY COMPLEX-II Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.093, year: 2015

  17. Entropy Generation Minimization in Dimethyl Ether Synthesis: A Case Study

    Science.gov (United States)

    Kingston, Diego; Razzitte, Adrián César

    2018-04-01

    Entropy generation minimization is a method that helps improve the efficiency of real processes and devices. In this article, we study the entropy production (due to chemical reactions, heat exchange and friction) in a conventional reactor that synthesizes dimethyl ether and minimize it by modifying different operating variables of the reactor, such as composition, temperature and pressure, while aiming at a fixed production of dimethyl ether. Our results indicate that it is possible to reduce the entropy production rate by nearly 70 % and that, by changing only the inlet composition, it is possible to cut it by nearly 40 %, though this comes at the expense of greater dissipation due to heat transfer. We also study the alternative of coupling the reactor with another, where dehydrogenation of methylcyclohexane takes place. In that case, entropy generation can be reduced by 54 %, when pressure, temperature and inlet molar flows are varied. These examples show that entropy generation analysis can be a valuable tool in engineering design and applications aiming at process intensification and efficient operation of plant equipment.

  18. Multicomponent synthesis of 4,4-dimethyl sterol analogues and their effect on eukaryotic cells.

    Science.gov (United States)

    Alonso, Fernando; Cirigliano, Adriana M; Dávola, María Eugenia; Cabrera, Gabriela M; García Liñares, Guadalupe E; Labriola, Carlos; Barquero, Andrea A; Ramírez, Javier A

    2014-06-01

    Most sterols, such as cholesterol and ergosterol, become functional only after the removal of the two methyl groups at C-4 from their biosynthetic precursors. Nevertheless, some findings suggest that 4,4-dimethyl sterols might be involved in specific physiological processes. In this paper we present the synthesis of a collection of analogues of 4,4-dimethyl sterols with a diamide side chain and a preliminary analysis of their in vitro activity on selected biological systems. The key step for the synthesis involves an Ugi condensation, a versatile multicomponent reaction. Some of the new compounds showed antifungal and cytotoxic activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Mutants of GABA transaminase (POP2 suppress the severe phenotype of succinic semialdehyde dehydrogenase (ssadh mutants in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Frank Ludewig

    Full Text Available BACKGROUND: The gamma-aminubutyrate (GABA shunt bypasses two steps of the tricarboxylic acid cycle, and is present in both prokaryotes and eukaryotes. In plants, the pathway is composed of the calcium/calmodulin-regulated cytosolic enzyme glutamate decarboxylase (GAD, the mitochondrial enzymes GABA transaminase (GABA-T; POP2 and succinic semialdehyde dehydrogenase (SSADH. We have previously shown that compromising the function of the GABA-shunt, by disrupting the SSADH gene of Arabidopsis, causes enhanced accumulation of reactive oxygen intermediates (ROIs and cell death in response to light and heat stress. However, to date, genetic investigations of the relationships between enzymes of the GABA shunt have not been reported. PRINCIPAL FINDINGS: To elucidate the role of succinic semialdehyde (SSA, gamma-hydroxybutyrate (GHB and GABA in the accumulation of ROIs, we combined two genetic approaches to suppress the severe phenotype of ssadh mutants. Analysis of double pop2 ssadh mutants revealed that pop2 is epistatic to ssadh. Moreover, we isolated EMS-generated mutants suppressing the phenotype of ssadh revealing two new pop2 alleles. By measuring thermoluminescence at high temperature, the peroxide contents of ssadh and pop2 mutants were evaluated, showing that only ssadh plants accumulate peroxides. In addition, pop2 ssadh seedlings are more sensitive to exogenous SSA or GHB relative to wild type, because GHB and/or SSA accumulate in these plants. SIGNIFICANCE: We conclude that the lack of supply of succinate and NADH to the TCA cycle is not responsible for the oxidative stress and growth retardations of ssadh mutants. Rather, we suggest that the accumulation of SSA, GHB, or both, produced downstream of the GABA-T transamination step, is toxic to the plants, resulting in high ROI levels and impaired development.

  20. Comparative genomics of aldehyde dehydrogenase 5a1 (succinate semialdehyde dehydrogenase and accumulation of gamma-hydroxybutyrate associated with its deficiency

    Directory of Open Access Journals (Sweden)

    Malaspina Patrizia

    2009-01-01

    Full Text Available Abstract Succinic semialdehyde dehydrogenase (SSADH; aldehyde dehydrogenase 5A1 [ALDH5A1]; locus 6p22 occupies a central position in central nervous system (CNS neurotransmitter metabolism as one of two enzymes necessary for γ-aminobutyric acid (GABA recycling from the synaptic cleft. Its importance is highlighted by the neurometabolic disease associated with its inherited deficiency in humans, as well as the severe epileptic phenotype observed in Aldh5a1-/- knockout mice. Expanding evidence now suggests, however, that even subtle decreases in human SSADH activity, associated with rare and common single nucleotide polymorphisms, may produce subclinical pathological effects. SSADH, in conjunction with aldo-keto reductase 7A2 (AKR7A2, represent two neural enzymes responsible for further catabolism of succinic semialdehyde, producing either succinate (SSADH or γ-hydroxybutyrate (GHB; AKR7A2. A GABA analogue, GHB is a short-chain fatty alcohol with unusual properties in the CNS and a long pharmacological history. Moreover, SSADH occupies a further role in the CNS as the enzyme responsible for further metabolism of the lipid peroxidation aldehyde 4-hydroxy-2-nonenal (4-HNE, an intermediate known to induce oxidant stress. Accordingly, subtle decreases in SSADH activity may have the capacity to lead to regional accumulation of neurotoxic intermediates (GHB, 4-HNE. Polymorphisms in SSADH gene structure may also associate with quantitative traits, including intelligence quotient and life expectancy. Further population-based studies of human SSADH activity promise to reveal additional properties of its function and additional roles in CNS tissue.

  1. Evaluation of the binding interaction between bovine serum albumin and dimethyl fumarate, an anti-inflammatory drug by multispectroscopic methods

    Science.gov (United States)

    Jattinagoudar, Laxmi; Meti, Manjunath; Nandibewoor, Sharanappa; Chimatadar, Shivamurti

    2016-03-01

    The information of the quenching reaction of bovine serum albumin with dimethyl fumarate is obtained by multi-spectroscopic methods. The number of binding sites, n and binding constants, KA were determined at different temperatures. The effect of increasing temperature on Stern-Volmer quenching constants (KD) indicates that a dynamic quenching mechanism is involved in the interaction. The analysis of thermodynamic quantities namely, ∆H° and ∆S° suggested hydrophobic forces playing a major role in the interaction between dimethyl fumarate and bovine serum albumin. The binding site of dimethyl fumarate on bovine serum albumin was determined by displacement studies, using the site probes viz., warfarin, ibuprofen and digitoxin. The determination of magnitude of the distance of approach for molecular interactions between dimethyl fumarate and bovine serum albumin is calculated according to the theory of Förster energy transfer. The CD, 3D fluorescence spectra, synchronous fluorescence measurements and FT-IR spectral results were indicative of the change in secondary structure of the protein. The influence of some of the metal ions on the binding interaction was also studied.

  2. Dimethyl Ether (DME) Assessment of Viscosity Using the New Volatile Fuel Viscometer (VFVM)

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Sorenson, Spencer C; Jakobsen, J.

    2001-01-01

    This paper describes the development and test of a viscometer capable of handling dimethyl Ether (DME) and other volatile fuels. DME has excellent combustion characteristics in diesel engines but the injection equipment can break down prematurely due to extensive wear when handling this fuel. It ...... is present in very large proportions. It is not believed that reasonably additised DME can reach the same viscosity and lubricity as diesel oil. The solution is rather to design the pumps so they can handle pure DME.......This paper describes the development and test of a viscometer capable of handling dimethyl Ether (DME) and other volatile fuels. DME has excellent combustion characteristics in diesel engines but the injection equipment can break down prematurely due to extensive wear when handling this fuel...

  3. Enantioselective epoxidation with chiral MN(III)(salen) catalysts: kinetic resolution of aryl-substituted allylic alcohols.

    Science.gov (United States)

    Adam, W; Humpf, H U; Roschmann, K J; Saha-Möller, C R

    2001-08-24

    A set of aryl-substituted allylic alcohols rac-2 has been epoxidized by chiral Mn(salen*) complexes 1 as the catalyst and iodosyl benzene (PhIO) as the oxygen source. Whereas one enantiomer of the allylic alcohol 2 is preferentially epoxidized to give the threo- or cis-epoxy alcohol 3 (up to 80% ee) as the main product (dr up to >95:5), the other enantiomer of 2 is enriched (up to 53% ee). In the case of 1,1-dimethyl-1,2-dihydronaphthalen-2-ol (2c), the CH oxidation to the enone 4c proceeds enantioselectively and competes with the epoxidation. The absolute configurations of the allylic alcohols 2 and their epoxides 3 have been determined by chemical correlation or CD spectroscopy. The observed diastereo- and enantioselectivities in the epoxidation reactions are rationalized in terms of a beneficial interplay between the hydroxy-directing effect and the attack along the Katsuki trajectory.

  4. [Changes in cell respiration of postural muscle fibers under long-term gravitational unloading after dietary succinate supplementation].

    Science.gov (United States)

    Ogneva, I V; Veselova, O M; Larina, I M

    2011-01-01

    The intensity of cell respiration of the rat m. soleus, m. gastrocnemius c.m. and tibialis anterior fibers during 35-day gravitational unloading, with the addition of succinate in the diet at a dosage rate of 50 mg per 1 kg animal weight has been investigated. The gravitational unloading was modeled by antiorthostatic hindlimb suspension. The intensity of cell respiration was estimated by polarography. It was shown that the rate of oxygen consumption by soleus and gastrocnemius fibers on endogenous and exogenous substrates and with the addition of ADP decreases after the discharge. This may be associated with the transition to the glycolytic energy path due to a decrease in the EMG-activity. At the same time, the respiration rate after the addition of exogenous substrates in soleus fibers did not increase, indicating a disturbance in the function of the NCCR-section of the respiratory chain and more pronounced changes in the structure of muscle fibers. In tibialis anterior fibers, no changes in oxygen consumption velocity were observed. The introduction of succinate to the diet of rats makes it possible to prevent the negative effects of hypokinesia, although it reduces the basal level of intensity of cell respiration.

  5. Mixed ligand complexes of essential metal ions with L-glutamine and succinic acid in SLS-water mixtures

    Directory of Open Access Journals (Sweden)

    Bindu Hima Gandham

    2012-01-01

    Full Text Available Speciation of mixed ligand complexes of Co(II, Ni(II and Cu(II with L-glutamine and succinic acid was studied in varying amounts (0.0-2.5% w/v of sodium lauryl sulphate in aqueous solutions maintaining an ionic strength of 0.16 mol L-1 (NaCl at 303.0 K. Titrations were carried out in the presence of different relative concentrations (M : L : X = 1 : 2 : 2, 1 : 4 : 2, 1 : 2 : 4 of metal (M to L-glutamine (L to succinic acid (X with sodium hydroxide. Stability constants of ternary complexes were refined with MINIQUAD75. The best-fit chemical models were selected based on statistical parameters and residual analysis. The species detected were ML2X, MLX, MLXH and MLXH2 for Co(II, Ni(II and Cu(II. Extra stability of ternary complexes compared to their binary complexes was believed to be due to electrostatic interactions of the side chains of ligands, charge neutralization, chelate effect, stacking interactions and hydrogen bonding. The species distribution with pH at different compositions of SLS and plausible equilibria for the formation of species were also presented.

  6. Effect of nanoclay loading on the thermal and mechanical properties of biodegradable Polylactide/Poly[(butylene succinate)- co-adipate] blend composites

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2012-04-01

    Full Text Available Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0...

  7. Metoprolol succinate extended release/hydrochlorothiazide combination tablets

    Directory of Open Access Journals (Sweden)

    James W Hainer

    2007-07-01

    Full Text Available James W Hainer, Jennifer SuggAstraZeneca LP, Wilmington, DE, USAAbstract: Lowering elevated blood pressure (BP with drug therapy reduces the risk for catastrophic fatal and nonfatal cardiovascular events such as stroke and myocardial infarction. Given the heterogeneity of hypertension as a disease, the marked variability in an individual patient’s BP response, and low response rates with monotherapy, expert groups such as the Joint National Committee (JNC emphasize the value of combination antihypertensive regimens, noting that combinations, usually of different classes, have additive antihypertensive effects. Metoprolol succinate extended-release tablet is a beta-1 (cardio-selective adrenoceptor-blocking agent formulated to provide controlled and predictable release of metoprolol. Hydrochlorothiazide (HCT is a well-established diuretic and antihypertensive agent, which promotes natruresis by acting on the distal renal tubule. The pharmacokinetics, efficacy, and safety/tolerability of the antihypertensive combination tablet, metoprolol extended release hydrochlorothiazide, essentially reflect the well-described independent characteristics of each of the component agents. Not only is the combination product more effective than monotherapy with the individual components but the combination product allows a low-dose multidrug regimen as an alternative to high-dose monotherapy, thereby, minimizing the likelihood of dose-related side-effects.Keywords: antihypertensive, blood pressure, cardiovascular disease, combination product

  8. Synthesis, characterization and crystal structure of 6-Chloro-4,4‧-dimethyl-2,2‧-bipyridine and 4,4‧-Dimethyl 2,2‧-bipyridine N-Oxide

    Science.gov (United States)

    Conterosito, Eleonora; Magistris, Claudio; Barolo, Claudia; Croce, Gianluca; Milanesio, Marco

    2016-03-01

    The synthesis, the NMR characterization and the crystal structure of 6-Chloro 4,4‧-dimethyl 2,2‧-bipyridine and of the reaction intermediate 4,4‧-Dimethyl 2,2‧-bipyridine N-Oxide are here reported. The target compound crystallizes in the orthorhombic system while the intermediate is monoclinic. In both structures, the molecules are linked by weak interactions. The structure of the reaction intermediate N-oxide is characterized by a dihedral angle between the two phenyl rings of 161.77° while the other is almost planar with a dihedral angle of 179.15°. The crystal packing was investigated, also with the aid of Hirshfeld surface analysis. In the N-oxide reaction intermediate the packing is governed by CH-O interactions, while in the product the packing is simply driven by minimizing the voids and thus maximizing the density, with a prevalence of H•••H and C•••H contacts, as indicated by fingerprint decomposition analysis.

  9. Thermodynamicy of Catalytic Formation of Dimethyl Ether from Methanol in Acidic Zeolites

    Czech Academy of Sciences Publication Activity Database

    Hyťha, Marek; Štich, I.; Gale, J. D.; Terakura, K.; Payne, M.

    2001-01-01

    Roč. 7, č. 12 (2001), s. 2521-2527 ISSN 0947-6539 Institutional research plan: CEZ:AV0Z1010914 Keywords : dimethyl ether * formation * theoretical study Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.614, year: 2001

  10. Synthesis and X-ray diffraction study of new uranyl malonate and oxalate complexes with carbamide

    International Nuclear Information System (INIS)

    Medvedkov, Ya. A.; Serezhkina, L. B.; Grigor’ev, M. S.; Serezhkin, V. N.

    2016-01-01

    Two new malonate-containing uranyl complexes with carbamide of the formulas [UO 2 (C 3 H 2 O 4 )(Urea) 2 ] (I) and [UO 2 (C 3 H 2 O 4 )(Urea) 3 ] (II), where Urea is carbamide, and one uranyl oxalate complex of the formula [UO 2 (C 2 O 4 )(Urea) 3 ] (III) were synthesized, and their crystals were studied by X-ray diffraction. The main structural units in crystals I are the electroneutral chains [UO 2 (C 3 H 2 O 4 )(Urea) 2 ] ∞ belonging to the crystal-chemical group AT 11 M 2 1 (A = UO 2 2+ , T 11 = C 3 H 2 O 4 2- , M 1 = Urea) of uranyl complexes. Crystals II and III are composed of the molecular complexes [UO 2 (L)(Urea) 3 ], where L = C 3 H 2 O 4 2- or C 2 O 4 2- , belonging to the crystal-chemical group AB 01 M 3 1 (A = UO 2 2+ , B 01 = C 3 H 2 O 4 2- or C 2 O 4 2- , M 1 = Urea). The characteristic features of the packing of the uranium-containing complexes are discussed in terms of molecular Voronoi–Dirichlet polyhedra. The effect of the Urea: U ratio on the structure of uranium-containing structural units is considered.

  11. Three-body dissociations: The photodissociation of dimethyl sulfoxide at 193 nm

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; North, S.W.; Stranges, D. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH{sub 3}SOCH{sub 3}) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH{sub 3} intermediate prior to dissociation to define a stepwise dissociation: (1) CH{sub 3}SOCH{sub 3} {r_arrow} 2CH{sub 3} + SO; (2a) CH{sub 3}SOCH{sub 3} {r_arrow} CH{sub 3} + SOCH{sub 3}; and (2b) SOCH{sub 3} {r_arrow} SO + CH{sub 3}. Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH{sub 3} and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 9.0.2.1. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH{sub 3} intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2.

  12. 5,5-Dimethyl-2-methylseleno-1,3,2-dioxaphosphorinan-2-one

    Directory of Open Access Journals (Sweden)

    Grzegorz Cholewinski

    2010-04-01

    Full Text Available The title compound, C6H13O3PSe, was obtained in the reaction of 5,5-dimethyl-2-oxo-2-seleno-1,3,2-dioxaphosphorinane potassium salt with methyl iodide. The selenomethyl group is in the axial position in relation to the six-membered dioxaphosphorinane ring.

  13. Organic acids enhance bioavailability of tetracycline in water to Escherichia coli for uptake and expression of antibiotic resistance.

    Science.gov (United States)

    Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

    2014-11-15

    Tetracyclines are a large class of antimicrobials used most extensively in livestock feeding operations. A large portion of tetracyclines administered to livestock is excreted in manure and urine which is collected in waste lagoons. Subsequent land application of these wastes introduces tetracyclines into the soil environment, where they could exert selective pressure for the development of antibiotic resistance genes in bacteria. Tetracyclines form metal-complexes in natural waters, which could reduce their bioavailability for bacterial uptake. We hypothesized that many naturally-occurring organic acids could effectively compete with tetracyclines as ligands for metal cations, hence altering the bioavailability of tetracyclines to bacteria in a manner that could enhance the selective pressure. In this study, we investigated the influence of acetic acid, succinic acid, malonic acid, oxalic acid and citric acid on tetracycline uptake from water by Escherichia coli bioreporter construct containing a tetracycline resistance gene which induces the emission of green fluorescence when activated. The presence of the added organic acid ligands altered tetracycline speciation in a manner that enhanced tetracycline uptake by E. coli. Increased bacterial uptake of tetracycline and concomitant enhanced antibiotic resistance response were quantified, and shown to be positively related to the degree of organic acid ligand complexation of metal cations in the order of citric acid > oxalic acid > malonic acid > succinic acid > acetic acid. The magnitude of the bioresponse increased with increasing aqueous organic acid concentration. Apparent positive relation between intracellular tetracycline concentration and zwitterionic tetracycline species in aqueous solution indicates that (net) neutral tetracycline is the species which most readily enters E. coli cells. Understanding how naturally-occurring organic acid ligands affect tetracycline speciation in solution, and how speciation

  14. Potentiometric and ab initio studies of acid-base interactions of substituted 4-halo(Cl, Br)pyridine N-oxide systems

    International Nuclear Information System (INIS)

    Gurzynski, Lukasz; Puszko, Aniela; Makowski, Mariusz; Makowska, Joanna; Chmurzynski, Lech

    2006-01-01

    By using the potentiometric method, acidity constants have been determined in systems of tri- and tetra-substituted pyridine N-oxides. The potentiometric measurements in systems of four 4-chloropyridine N-oxide derivatives containing the chlorine atom at position 4 to the NO 2 group and four bromine counterparts were carried out in polar non-aqueous solvents, viz. amphiprotic methanol (MeOH) and aprotic protophilic dimethyl sulfoxide (DMSO). It was found that in all the systems studied the pK a values were readily determinable (as indicated by small standard deviations) in MeOH, whereas in DMSO large standard deviations were obtained making the pK a values either hardly determinable or indeterminable from potentiometric measurements. Furthermore, it was demonstrated that the acidity constants of protonated N-oxides studied in MeOH changed according to the sequence of their acidity constants in water. It was also found that in the polar solvents studied, i.e. in the amphiprotic methanol and the highly basic aprotic dimethyl sulfoxide, the cationic homo-conjugation equlibrium constants could not be determined using potentiometric method. Also, by using ab initio methods at the RHF and MP2 levels and the PCM model, utilizing the Gaussian 6-31++G** basis set, energies and Gibbs free energies of the protonation reactions of the N-oxides have been determined. The energy parameters have been compared with acidity constants of the protonated N-oxides determined by potentiometric titration in methanol to establish a correlation between these approaches

  15. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted phenyl...

  16. Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

    Data.gov (United States)

    U.S. Environmental Protection Agency — A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon...

  17. The industrial production of dimethyl carbonate from methanol and carbon dioxide

    NARCIS (Netherlands)

    De Groot, Frank F T; Lammerink, Roy R G J; Heidemann, Casper; Van Der Werff, Michiel P M; Garcia, Taiga Cafiero; Van Der Ham, Louis A G J; Van Den Berg, Henk

    2014-01-01

    This work discusses the design of a dimethyl carbonate (DMC) production plant based on methanol and CO2 as feed materials, which are a cheap and environment-friendly feedstock. DMC is a good alternative for methyl-tert-butyl ether (MTBE) as a fuel oxygenating agent, due to its low toxicity and fast

  18. Optimization of sodium hydroxide pretreatment and enzyme loading for efficient hydrolysis of rice straw to improve succinate production by metabolically engineered Escherichia coli KJ122 under simultaneous saccharification and fermentation.

    Science.gov (United States)

    Sawisit, Apichai; Jampatesh, Surawee; Jantama, Sirima Suvarnakuta; Jantama, Kaemwich

    2018-07-01

    Rice straw was pretreated with sodium hydroxide (NaOH) before subsequent use for succinate production by Escherichia coli KJ122 under simultaneous saccharification and fermentation (SSF). The NaOH pretreated rice straw was significantly enhanced lignin removal up to 95%. With the optimized enzyme loading of 4% cellulase complex + 0.5% xylanase (endo-glucanase 67 CMC-U/g, β-glucosidase 26 pNG-U/g and xylanase 18 CMC-U/g dry biomass), total sugar conversion reached 91.7 ± 0.8% (w/w). The physicochemical analysis of NaOH pretreated rice straw indicated dramatical changes in its structure, thereby favoring enzymatic saccharification. In batch SSF, succinate production of 69.8 ± 0.3 g/L with yield and productivity of 0.84 g/g pretreated rice straw and 0.76 ± 0.02 g/L/h, respectively, was obtained. Fed-batch SSF significantly improved succinate concentration and productivity to 103.1 ± 0.4 g/L and 1.37 ± 0.07 g/L/h with a comparable yield. The results demonstrated a feasibility of sequential saccharification and fermentation of rice straw as a promising process for succinate production in industrial scale. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. γ-ray dosimetry using pararosaniline cyanide in dimethyl sulfoxide solutions

    International Nuclear Information System (INIS)

    El-Assy, N.B.; Roushdy, H.M.; Rageh, M.; McLaughlin, W.L.; Levine, H.

    1982-01-01

    A chemical radiochromic dosimeter using pararosaniline cyanide in dimethyl sulfoxide can be used over a wide absorbed dose range. Experiments show that the dosimeter has a main optical absorption maximum at 554nm, which is 5nm higher than that of other polar solvents. Millimolar solutions of leucodye containing small amounts of carboxylic acid or nitrobenzene show a linear response for absorbed doses up to 11.75kGy. The yield of dye is linear with concentration up to 5mM. At that concentration the upper limit of linear response range can be extended to about 40kGy. The lower dose limit for 50mM concentration of the dye precursor hexahydroxyethyl pararosaniline (lambdasub(max)=608nm) is about 3Gy, with +-5%SD at a 95% confidence level, when using a 5cm pathlength cell. Dye formation yield varies not only with concentration of the leucocyanide, but also with type of oxidizing agent and temperature during irradiation. The latter parameter is especially critical, as dimethyl sulfoxide freezes at 17 0 C. The effect of storage temperature on the color produced after irradiation at different dose levels was also studied. (author)

  20. No evidence for promoter region methylation of the succinate dehydrogenase and fumarate hydratase tumour suppressor genes in breast cancer

    Directory of Open Access Journals (Sweden)

    Dobrovic Alexander

    2009-09-01

    Full Text Available Abstract Background Succinate dehydrogenase (SDH and fumarate hydratase (FH are tricarboxylic acid (TCA cycle enzymes that are also known to act as tumour suppressor genes. Increased succinate or fumarate levels as a consequence of SDH and FH deficiency inhibit hypoxia inducible factor-1α (HIF-1α prolyl hydroxylases leading to sustained HIF-1α expression in tumours. Since HIF-1α is frequently expressed in breast carcinomas, DNA methylation at the promoter regions of the SDHA, SDHB, SDHC and SDHD and FH genes was evaluated as a possible mechanism in silencing of SDH and FH expression in breast carcinomas. Findings No DNA methylation was identified in the promoter regions of the SDHA, SDHB, SDHC, SDHD and FH genes in 72 breast carcinomas and 10 breast cancer cell lines using methylation-sensitive high resolution melting which detects both homogeneous and heterogeneous methylation. Conclusion These results show that inactivation via DNA methylation of the promoter CpG islands of SDH and FH is unlikely to play a major role in sporadic breast carcinomas.

  1. Dimethyl ether production from methanol and/or syngas

    Science.gov (United States)

    Dagle, Robert A; Wang, Yong; Baker, Eddie G; Hu, Jianli

    2015-02-17

    Disclosed are methods for producing dimethyl ether (DME) from methanol and for producing DME directly from syngas, such as syngas from biomass. Also disclosed are apparatus for DME production. The disclosed processes generally function at higher temperatures with lower contact times and at lower pressures than conventional processes so as to produce higher DME yields than do conventional processes. Certain embodiments of the processes are carried out in reactors providing greater surface to volume ratios than the presently used DME reactors. Certain embodiments of the processes are carried out in systems comprising multiple microchannel reactors.

  2. Pyrole-substituted barbituric derivatives as pharmaceutically significant compounds and intermediates

    International Nuclear Information System (INIS)

    Bijev, A.; Prodanova, P.

    2004-01-01

    Pyrrole- and indolecarbaldehydes are condensed with 5-unsubstituted barbituric acids targeting 16 new heterocyclic structures with a prospective pharmacological profile. So 1H-2-pyrrolecarbaldehyde, diethyl 5-formyl-3-methyl-1H-2,4-pyrroledicarboxylate, ethyl 5-formy 1-2,4-dimethyl-l.fl'-3-pyrrolecarboxylate, ethyl 4-formyl-3,5-dimethyl-1H-2-pyrrolecarboxylate, ethyl 4-formyl-2,5-dimethyl-1H-3-pyrrolecarboxylate and l-acetyl-1H-3-indolecarbaldehyde have been condensed in a molar ratio with hexahydro-2,4,6-pyrimidinetrione (barbituric acid) and its 1,3-dimethyl-, 1,3-diphenyl- and 1,3-dicyclohexyl- derivatives. The synthesis takes place in ethanol (or in ethanol/water in the cases of unsubstituted barbituric acid) within several hours at 20 0 - 60 0 C in the absence of any catalyst with yields in the range of 70-95%. An insufficient carbonyl activity of N-unsubstituted indole-3-carbaldehyde has been observed and overcome by a preliminary N-acethylation avoiding the inactive vinylene-carboxamide form. In addition to their pharmaceutical significance based on the interaction of two heterocyclic pharmacophores, the condensation products could also be useful as versatile intermediates for further synthesis of new heterocyclic systems. The synthesis of 5-[(4-acetyl-3,5-dimethyl-1H-2-pyrrolyl)(l-acetyl-1H-3-indolyl)methyl] hexahydr= o-2,4,6-pyrimidinetrione (60% in enol-form according to 1 H-NMR) by refluxing of [(1-acetyl-1H-3-indolyl) methylene]hexahydro-2,4,6-pyrimidinetrione] and 3-acethyl-2,4-dimethylpyrrole for 6 h in CH 3 CN illustrates their capability to add C-nucleophiles to the double bound bridging 3 heterocyclic units together. The new 17 products are TLC pure and their structures are proved by 1 H-NMR/IR-spectra which interpretation is displayed. (authors)

  3. Establishment of Dimethyl Labeling-based Quantitative Acetylproteomics in Arabidopsis.

    Science.gov (United States)

    Liu, Shichang; Yu, Fengchao; Yang, Zhu; Wang, Tingliang; Xiong, Hairong; Chang, Caren; Yu, Weichuan; Li, Ning

    2018-05-01

    Protein acetylation, one of many types of post-translational modifications (PTMs), is involved in a variety of biological and cellular processes. In the present study, we applied both C sCl d ensity g radient (CDG) centrifugation-based protein fractionation and a dimethyl-labeling-based 4C quantitative PTM proteomics workflow in the study of dynamic acetylproteomic changes in Arabidopsis. This workflow integrates the dimethyl c hemical labeling with c hromatography-based acetylpeptide separation and enrichment followed by mass spectrometry (MS) analysis, the extracted ion chromatogram (XIC) quantitation-based c omputational analysis of mass spectrometry data to measure dynamic changes of acetylpeptide level using an in-house software program, named S table isotope-based Qua ntitation- D imethyl labeling (SQUA-D), and finally the c onfirmation of ethylene hormone-regulated acetylation using immunoblot analysis. Eventually, using this proteomic approach, 7456 unambiguous acetylation sites were found from 2638 different acetylproteins, and 5250 acetylation sites, including 5233 sites on lysine side chain and 17 sites on protein N termini, were identified repetitively. Out of these repetitively discovered acetylation sites, 4228 sites on lysine side chain ( i.e. 80.5%) are novel. These acetylproteins are exemplified by the histone superfamily, ribosomal and heat shock proteins, and proteins related to stress/stimulus responses and energy metabolism. The novel acetylproteins enriched by the CDG centrifugation fractionation contain many cellular trafficking proteins, membrane-bound receptors, and receptor-like kinases, which are mostly involved in brassinosteroid, light, gravity, and development signaling. In addition, we identified 12 highly conserved acetylation site motifs within histones, P-glycoproteins, actin depolymerizing factors, ATPases, transcription factors, and receptor-like kinases. Using SQUA-D software, we have quantified 33 ethylene hormone-enhanced and

  4. Catalyst activity maintenance study for the liquid phase dimethyl ether process

    Energy Technology Data Exchange (ETDEWEB)

    Peng, X.D.; Toseland, B.A.; Underwood, R.P. [Air Products and Chemicals, Inc., Allentown, PA (United States)

    1995-12-31

    The co-production of dimethyl ether (DME) and methanol from syngas is a process of considerable commercial attractiveness. DME coproduction can double the productivity of a LPMEOH process when using coal-derived syngas. This in itself may offer chemical producers and power companies increased flexibility and more profitable operation. DME is also known as a clean burning liquid fuel; Amoco and Haldor-Topsoe have recently announced the use of DME as an alternative diesel fuel. Moreover, DME can be an interesting intermediate in the production of chemicals such as olefins and vinyl acetate. The current APCl liquid phase dimethyl ether (LPDME) process utilizes a physical mixture of a commercial methanol synthesis catalyst and a dehydration catalyst (e.g., {gamma}-alumina). While this arrangement provides a synergy that results in much higher syngas conversion per pass compared to the methanol-only process, the stability of the catalyst system suffers. The present project is aimed at reducing catalyst deactivation both by understanding the cause(s) of catalyst deactivation and by developing modified catalyst systems. This paper describes the current understanding of the deactivation mechanism.

  5. Preparation of phenyl, p-fluorophenyl, 2-thienyl {beta} alanines {beta} -{sup 14}C; Preparation de phenyl, p-fluorophenyl, thienyl-2 {beta} alanines {beta} - {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Pichat, L; Carbonnier, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    Description of the synthesis of the amino acids given in the title, labelled with {sup 14}C in the beta position. Benzoic, fluorobenzoic and thenoic acids carboxyl {sup 14}C prepared from {sup 14}CO{sub 2} from converted respectively to benzyl chloride, p-fluorobenzyl chloride and 2-chloromethyl thiophene, which were condensed in dimethyl-formamide solution with sodium ethyl acetamido malonate. After hydrobromic hydrolysis the desired products were obtained with respective overall yields of 64, 49 and 57 per cent. (author) [French] Description de la synthese des acides amines du titre, marques au {sup 14}C en position beta. Les acides benzoique, fluorobenzoique, thenoique carboxyl {sup 19}C prepares a partir de {sup 14}CO{sub 2} ont ete transformes respectivement en chlorure de benzyle, chlorure de p-fluorobenzyle, chloromethyl-2 thiophene lesquels ont ete condenses dans le dimethyl-formamide sur l'acetamidomalonate d'ethyle sode. Apres hydrolyse bromhydrique, on a obtenu les produits cherches avec les rendements globaux respectifs de 64, 39 et 57 pour cent. (auteur)

  6. Culture engineering examination and metabolism flux distribution system analysis for madding to convert into poly {beta}- hydroxybutyric acid (PHB) using the hydrogen bacteria of organic acid got in liquid-phase oxidation of lignite; Kattan no ekiso sanka de erareru yukisan wo suiso saikin wo riyoshite pori {beta}-hidorokishi rakusan(PHB) ni henkan saseru tameno baiyo kogakuteki kento to taisha ryusoku bunpu shisutemu kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, Kinko; Seki, Suito; Shimizu, Kazuyuki; Mae, Kazuhiro; Miura, Koichi

    1999-04-05

    The culture engineering examination for madding to convert into poly {beta} - hydroxy Wisteria (PHB) which glycolic acid. Acetic acid, ant acid, malonic acid got in liquid-phase oxidation of lignite are raw material of biodegradable plastic using hydrogen bacteria Alcaligenes eutrophus was carried out. It was proven that acetic acid was the most efficiently converted into the PHB as a result of cultivating these organic acid as a single carbon source. And, it was utilized to the bacterial cell at the order of ant acid, acetic acid, glycolic acid, when it was cultivated in mixing organic acid, and it was proven to convert into the PHB. Though the malonic acid was not utilized for the bacterial cell breeding, it was indicated that as the result which analyzed metabolism flow distribution by calculating using the culture data, the succinate dehydrogenase of the tricarboxylic acid (TCA) circuit received competitive inhibition, when this is added in culture middle point, and that the flux of griot lysyl acid route and gluconeogenesis route lowers. And, it was proven that it was utilized in the route which comes to the PHB synthesis from acetoacetyl CoA with the lowering of the ammonia concentration on NADPH produced from the isocitric acid, though it was prior consumed to the glutamic acid of tricarboxylic acid cycle in the route, if ammonia concentration is high. (translated by NEDO)

  7. 1,5-Dimethyl-2-phenyl-1H-pyrazol-3(2H-one–4,4′-(propane-2,2-diylbis[1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one] (1/1

    Directory of Open Access Journals (Sweden)

    Krzysztof Lyczko

    2013-01-01

    Full Text Available The asymmetric unit of the title compound, C11H12N2O·C25H28N4O2, contains two different molecules. The smaller is known as antipyrine [systematic name: 1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one] and the larger is built up from two antypirine molecules which are connected through a C atom of the pyrazolone ring to a central propanyl part [systematic name: 4,4′-(propane-2,2-diylbis[1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one]. Intramolecular C—H...O hydrogen bonds occur in the latter molecule. In the crystal, C—H...O hydrogen bonds link the molecules into a two-dimensional network parallel to (001.

  8. 16,16-dimethyl prostaglandin E2 increases survival of murine intestinal stem cells when given before photon radiation

    International Nuclear Information System (INIS)

    Hanson, W.R.; Thomas, C.

    1983-01-01

    A variety of prostaglandins (PG) protect the gastric and intestinal mucosa when given before damaging agents as absolute ethanol, acidified taurocholate, boiling water, or nonsteroidal anti-inflammatory agents (NSAI). A synthetic prostaglandin, 16,16-dimethyl PGE 2 , shown to be cytoprotective at physiologic levels to the above agents was given to mice 1 h before or 15 min after 137 Cs gamma(γ) whole-body irradiation. The survival of intestinal stem cells measured by their ability to form in situ colonies of regenerating epithelium was increased stem cells measured by their ability to form in situ colonies of regenerating epithelium was increased when 16,16-dimethyl PGE 2 was given before but not after 137 Cs γ irradiation. The maximum degree of 16,16-dimethyl PGE 2 -induced radioprotection was seen when the drug was given 1 h before irradiation. No radioprotection was seen when the interval between drug and irradiation was 3 h or longer. When the time between 16,16-dimethyl PGE 2 and irradiation was kept at 1 h, the degree of radioprotection was dependent on the PG drug dose. There was a steep rise in the number of surviving cells at low doses of PG. These results imply that tumors which secrete PGE 2 may in part be protected from the lethal effects of ionizing photon radiation

  9. Dimethyl sulfoxide complexing with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Borovikov, Yu Ya; Serguchev, Yu A; Staninets, V I

    1986-01-01

    Dielectrometry, conductometry, IR-spectroscopy are used to study dimethyl sulfoxide complexing with iodine in binary system and in CCl/sub 4/, C/sub 6/H/sub 6/, C/sub 6/H/sub 5/Cl, C/sub 6/H/sub 5/CF/sub 3/, 1, 2-dichloroethane solutions. Complexes of 1:1 composition are formed in solutions, in the binary system of 2:1 and 2:2 composition. I/sub 2/ molecules add to oxygen atoms. In CCl/sub 4/ and in binary system gradual transformation of so called external charge transfer complexes (CTC-1) to internal ones (CTC-2) that are described by the 1st order reaction kinetic equations is observed. On dissolution of CTC of 2:2 composition they disproportionate into two CTC molecules 1:1. Enthalpy of forming CTC-1 1:1 is approximately 4 kcal/mol, CTC-2 1:1 - 8, CTC-1 2:1 - 8 kcal/mol.

  10. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Andre L. Boehman; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. The strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The laboratory studies have included work with a Navistar V-8 turbodiesel engine, demonstration of engine operation on DME-diesel blends and instrumentation for evaluating fuel properties. The field studies have involved performance, efficiency and emissions measurements with the Champion Motorcoach ''Defender'' shuttle bus which will be converted to DME-fueling. The results include baseline emissions, performance and combustion measurements on the Navistar engine for operation on a federal low sulfur diesel fuel (300 ppm S). Most recently, they have completed engine combustion studies on DME-diesel blends up to 30 wt% DME addition.

  11. Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Mobin

    2012-12-01

    Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

  12. Succinic acid production derived from carbohydrates: An energy and greenhouse gas assessment of a platform chemical toward a bio-based economy

    NARCIS (Netherlands)

    Cok, B.|info:eu-repo/dai/nl/371750679; Tsiropoulos, I.; Roes, A.L.|info:eu-repo/dai/nl/303022388; Patel, M.K.|info:eu-repo/dai/nl/18988097X

    2014-01-01

    Bio-based succinic acid has the potential to become a platform chemical, i.e. a key building block for deriving both commodity and high-value chemicals, which makes it an attractive compound in a bio-based economy. A few companies and industrial consortia have begun to develop its industrial

  13. Synthesis, characterization and antimicrobial activities of novel silver(I) complexes with coumarin substituted N-heterocyclic carbene ligands.

    Science.gov (United States)

    Karataş, Mert Olgun; Olgundeniz, Begüm; Günal, Selami; Özdemir, İlknur; Alıcı, Bülent; Çetinkaya, Engin

    2016-02-15

    Eight new coumarin substituted silver(I) N-heterocyclic carbene (NHC) complexes were synthesized by the interaction of the corresponding imidazolium or benzimidazolium chlorides and Ag2O in dichloromethane at room temperature. Structures of these complexes were established on the basis of elemental analysis, (1)H NMR, (13)C NMR, IR and mass spectroscopic techniques. The antimicrobial activities of carbene precursors and silver NHC complexes were tested against standard strains: Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and the fungi Candida albicans and Candida tropicalis. Results showed that all the compounds inhibited the growth of the all bacteria and fungi strains and some complexes performed good activities against different microorganisms. Among all the compounds, the most lipophilic complex bis[1-(4-methylene-6,8-dimethyl-2H-chromen-2-one)-3-(naphthalene-2-ylmethyl)benzimidazol-2-ylidene]silver(I) dichloro argentate (5e) was found out as the most active one. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

    Science.gov (United States)

    Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

    2014-10-01

    The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

  15. DNA replication origin function is promoted by H3K4 di-methylation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Rizzardi, Lindsay F; Dorn, Elizabeth S; Strahl, Brian D; Cook, Jeanette Gowen

    2012-10-01

    DNA replication is a highly regulated process that is initiated from replication origins, but the elements of chromatin structure that contribute to origin activity have not been fully elucidated. To identify histone post-translational modifications important for DNA replication, we initiated a genetic screen to identify interactions between genes encoding chromatin-modifying enzymes and those encoding proteins required for origin function in the budding yeast Saccharomyces cerevisiae. We found that enzymes required for histone H3K4 methylation, both the histone methyltransferase Set1 and the E3 ubiquitin ligase Bre1, are required for robust growth of several hypomorphic replication mutants, including cdc6-1. Consistent with a role for these enzymes in DNA replication, we found that both Set1 and Bre1 are required for efficient minichromosome maintenance. These phenotypes are recapitulated in yeast strains bearing mutations in the histone substrates (H3K4 and H2BK123). Set1 functions as part of the COMPASS complex to mono-, di-, and tri-methylate H3K4. By analyzing strains lacking specific COMPASS complex members or containing H2B mutations that differentially affect H3K4 methylation states, we determined that these replication defects were due to loss of H3K4 di-methylation. Furthermore, histone H3K4 di-methylation is enriched at chromosomal origins. These data suggest that H3K4 di-methylation is necessary and sufficient for normal origin function. We propose that histone H3K4 di-methylation functions in concert with other histone post-translational modifications to support robust genome duplication.

  16. Application of stable isotope ratio analysis explaining the bioformation of 2,5-dimethyl-4-hydroxy-3(2H)-furanone in plants by a biological Maillard reaction

    International Nuclear Information System (INIS)

    Schwab, W.

    1998-01-01

    [1-13C]-D-Fructose and [U-13C6]-D-fructose were applied to detached ripening strawberry fruits, and the incorporation into 2,5-dimethyl-4-hydroxy-3(2H)-furanone 1, 2,5-dimethyl-4-methoxy-3(2H)-furanone 2, 2,5-dimethyl-4-acetoxy-3(2H)-furanone 3, 2,5-dimethyl-4-hydroxy-3(2H)-furanone beta-D-glucopyranoside 4, and 2,5-dimethyl-4-hydroxy-3(2H)-furanone 6'-O-malonyl beta-D-glucopyranoside 5 was determined by HRGC-MS and HPLC-ESI MS-MS. The data clearly showed the direct conversion of D-fructose to the furanones without cleavage of the carbohydrate prior to the formation of 1-5, as expected for a biological Maillard reaction. Both, the furanone and the D-glucose moiety of 4 and 5 contained the labels. However, the label was primarily incorporated into the furanone moiety, indicating that D-fructose is a more efficient precursor of the furanones than D-glucose

  17. Organocatalytic asymmetric michael addition of aldehydes to beta-nitroacroleine dimethyl acetal.

    Science.gov (United States)

    Reyes, Efraim; Vicario, Jose L; Badía, Dolores; Carrillo, Luisa

    2006-12-21

    [Structure: see text] The organocatalytic asymmetric Michael addition of aldehydes to beta-nitroacroleine dimethyl acetal has been studied in detail. The reaction took place with excellent yields and high stereoselectivities when a chiral beta-amino alcohol such as L-prolinol was employed as the catalyst, leaving a formation of highly functionalized enantioenriched compounds containing two differentiated formyl groups together with a nitro moiety.

  18. [The substitution effect of leadership substitutes for transformational leadership in nursing organization].

    Science.gov (United States)

    Kim, Jeong-Hee

    2006-04-01

    This paper was conducted to examine the effects of transformational leadership behaviors, within the substitutes for leadership model (Kerr & Jermier, 1978). Data was collected from 181 staff nurses in 3 general hospitals, with self-reporting questionnaires (MLQ developed by Bass, rd-SLS developed by Podsakoff, et al., and MSQ developed by Weiss, et al.). Descriptive statistics, factor analysis, Cronbach's alpha and moderated regression analysis were used. 1) The transformational leader behaviors and substitutes for leadership each had correlations with job satisfaction. 2) The total amount of variance accounted for by the substitutes for leadership was substantially greater than by the transformational leadership behaviors. 3) Few of the substitutes variables moderated the relationships between the transformational leader behaviors and job satisfaction in a manner consistent with that specified by Howell, Dorfman, and Kerr (1986). The finding of this study suggest that leaders need to have a better understanding of those contextual variables that influence job satisfaction. Thus future research should focus attention on the moderating effects of substitutes, as well as the things that leaders can do to influence them. In addition, it may be good to examine the effects of substitutes on other criterion variables.

  19. Metabolism of 14C-labeled doxylamine succinate (Bendectin) in the rhesus monkey (Macaca mulatta)

    International Nuclear Information System (INIS)

    Slikker, W. Jr.; Holder, C.L.; Lipe, G.W.; Korfmacher, W.A.; Thompson, H.C. Jr.; Bailey, J.R.

    1986-01-01

    The time-course of the metabolic fate of [ 14 C]doxylamine was determined after the p.o. administration of 13 mg/kg doxylamine succinate as Bendectin plus [ 14 C]doxylamine succinate to the rhesus monkey. Urine and plasma samples were analyzed by reversed-phase high performance liquid chromatography (HPLC), chemical derivatization, and mass spectrometry. The cumulative 48-hr urinary metabolic profile contained 81% of the administered radiolabeled dose and consisted of at least six radiolabeled peaks. They were peak 1: unknown polar metabolites (8% of dose); peak 2: 2-[1-phenyl-1-(2-pyridinyl)ethoxy] acetic acid, 1-[1-phenyl-1(2-pyridinyl)ethoxy] methanol, and another minor metabolite(s) (31%); peak 3: doxylamine-N-oxide (1%); peak 4a: N,N-didesmethyldoxylamine (17%); peak 4b: doxylamine (4%); and peak 5: N-desmethyldoxylamine (20%). The plasma metabolic profile was the same as the urinary profile except for the absence of doxylamine-N-oxide. The maximum plasma concentrations and elapsed time to attain these concentrations were as follows. Peak 1: 540 ng/mL, 4 hr; peak 2: 1700 ng/mL, 1 hr; peak 4a: 430 ng/mL, 4 hr; peak 4b: 930 ng/mL, 2 hr; and peak 5: 790 ng/mL, 2 hr. These data suggest that in the monkey, doxylamine metabolism follows at least four pathways: a minor pathway to the N-oxide; a minor pathway to unknown polar metabolites; a major pathway to mono- and didesmethyldoxylamine via successive N-demethylation; and a major pathway to side-chain cleavage products (peak 2) via direct side-chain oxidation and/or deamination

  20. Ultrasound Promoted Synthesis of Bis(substituted pyrazol-4-ylcarbonyl-Substituted Thioureas

    Directory of Open Access Journals (Sweden)

    Li Xiao

    2009-03-01

    Full Text Available A series of novel bis(substituted pyrazol-4-ylcarbonyl-substituted thioureas have been synthesized by the reactions of substituted pyrazol-4-ylcarbonyl isothiocyanates with different diamines under ultrasound irradiation and classical heating method at 20-25 °C. In general, substantial improvement in rates and modest yields increases were observed when reactions were carried out under sonication, compared with the classical heating method. The structures of these compounds have been elucidated by elemental and spectral (IR, 1H-NMR analysis.

  1. Polymer blends of polylactic acid (PLA) and polybutylene succinate-adipate

    Science.gov (United States)

    Ma, Wenguang

    A series of blends consisting of polylactic acid (PLA) and aliphatic succinate polyester (BionolleRTM #3000) had been prepared and investigated. The results of mechanical property investigations showed that using 20 wt% Bionolle#3000 can significantly increase the toughness of PLA. BionolleRTM #3000 also reduces the physical aging rate of PLA so blends remain tough longer. Conversely, the stiffness of BionolleRTM #3000 can be significantly increased by blending in PLA. DMA and DSC results show that PLA/BionolleRTM 3000 blends are not thermodynamically miscible, but are compatible blends. Studies have also been performed to determine the amount and rate of aerobic biodegradation of PLA/aliphatic succinate polyester blends in biologically active composting, enzymatic, and soil environments. The changes in molecular weight, molecular structure and thermal properties in the composting environment were also studied by GPC, NMR and DSC analyses. The research results showed BionolleRTM #3000 had a high degradation rate, while PLA had a low degradation rate. PLA/BionolleRTM #3000 blends had moderate degradation rates that increased with BionolleRTM #3000 content. The melt flow behavior of PLA/BionolleRTM #3000 blends has been studied by capillary rheometry. The relationship of the blends' viscosity with their composition, shear stress, shear rate, and temperature has been investigated. Power law index and activation energy of PLA, BionolleRTM #3000 and their blends have been calculated. The experimental and theoretical data can let us understand the processability of PLA/BionolleRTM #3000 blends. A scanning electron microscope (SEM) was used to investigate the morphological structure of the PLA/BionolleRTM #3000 blends. Micrographs of the samples made from different methods (blown film, extrudate and compression molding sheet) were taken; their differences in morphology were compared. For comparison, the micrographs of blend PLA/BionolleRTM #6000 was also studied. The

  2. Vickers microhardness studies on solution-grown single crystals of potassium boro-succinate

    Science.gov (United States)

    Lakshmipriya, M.; Rajan Babu, D.; Ezhil Vizhi, R.

    2015-02-01

    The semiorganic crystals of potassium boro-succinate (KBS) were grown by slow evaporation method. KBS crystallizes in monoclinic system which was confirmed by powder XRD analysis. Vickers microhardness study has been carried out over a load range of 25-100 g. The Vickers hardness numbers (Hv) of the material increases as the load increases so the material is suitable for device fabrication. The Meyer index 'n' is estimated to be greater than 1.6, the crystal system belongs to the soft material category. The elastic stiffness coefficient, c11, has also been calculated using Wooster's empirical relation from the hardness data. The fracture toughness values 'Kc', determined from measurements of crack lengths, were estimated to be 0.15166 MN/m3/2. The brittleness indices 'Bi' were estimated as 276 m-1/2.

  3. Heat capacities and asymmetric criticality of the (liquid + liquid) coexistence curves for {dimethyl carbonate + n-undecane, or n-tridecane}

    International Nuclear Information System (INIS)

    Chen, Zhiyun; Shi, Aiqin; Liu, Shixia; Yin, Tianxiang; Shen, Weiguo

    2014-01-01

    Highlights: • Coexistence curves of dimethyl carbonate + n-undecane (or + n-tridecane) were measured. • Isobaric heat capacity per unit volume of critical binary solutions dimethyl carbonate + n-undecane (or + n-tridecane) were determined. • The critical exponent β are consistent with the 3D-Ising value. • The asymmetry of the coexistence curves were discussed by the complete scaling theory. - Abstract: The (liquid + liquid) coexistences and the critical behavior of isobaric heat capacity per unit volume for critical binary solutions {dimethyl carbonate + n-undecane, or n-tridecane} have been studied. The critical exponents β and α were deduced and found to be consistent with the 3D-Ising values. The critical amplitudes were determined and used to test the asymmetric criticality of coexistence curves. It was found that the heat capacity does play an important role in describing the asymmetric criticality of the coexistence curves

  4. Importance of methodology on (99m)technetium dimercapto-succinic acid scintigraphic image quality: imaging pilot study for RIVUR (Randomized Intervention for Children With Vesicoureteral Reflux) multicenter investigation.

    Science.gov (United States)

    Ziessman, Harvey A; Majd, Massoud

    2009-07-01

    We reviewed our experience with (99m)technetium dimercapto-succinic acid scintigraphy obtained during an imaging pilot study for a multicenter investigation (Randomized Intervention for Children With Vesicoureteral Reflux) of the effectiveness of daily antimicrobial prophylaxis for preventing recurrent urinary tract infection and renal scarring. We analyzed imaging methodology and its relation to diagnostic image quality. (99m)Technetium dimercapto-succinic acid imaging guidelines were provided to participating sites. High-resolution planar imaging with parallel hole or pinhole collimation was required. Two core reviewers evaluated all submitted images. Analysis included appropriate views, presence or lack of patient motion, adequate magnification, sufficient counts and diagnostic image quality. Inter-reader agreement was evaluated. We evaluated 70, (99m)technetium dimercapto-succinic acid studies from 14 institutions. Variability was noted in methodology and image quality. Correlation (r value) between dose administered and patient age was 0.780. For parallel hole collimator imaging good correlation was noted between activity administered and counts (r = 0.800). For pinhole imaging the correlation was poor (r = 0.110). A total of 10 studies (17%) were rejected for quality issues of motion, kidney overlap, inadequate magnification, inadequate counts and poor quality images. The submitting institution was informed and provided with recommendations for improving quality, and resubmission of another study was required. Only 4 studies (6%) were judged differently by the 2 reviewers, and the differences were minor. Methodology and image quality for (99m)technetium dimercapto-succinic acid scintigraphy varied more than expected between institutions. The most common reason for poor image quality was inadequate count acquisition with insufficient attention to the tradeoff between administered dose, length of image acquisition, start time of imaging and resulting image

  5. Potentiometric and ab initio studies of acid-base interactions of substituted 4-halo(Cl, Br)pyridine N-oxide systems

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowska, Joanna [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2006-12-15

    By using the potentiometric method, acidity constants have been determined in systems of tri- and tetra-substituted pyridine N-oxides. The potentiometric measurements in systems of four 4-chloropyridine N-oxide derivatives containing the chlorine atom at position 4 to the NO{sub 2} group and four bromine counterparts were carried out in polar non-aqueous solvents, viz. amphiprotic methanol (MeOH) and aprotic protophilic dimethyl sulfoxide (DMSO). It was found that in all the systems studied the pK {sub a} values were readily determinable (as indicated by small standard deviations) in MeOH, whereas in DMSO large standard deviations were obtained making the pK {sub a} values either hardly determinable or indeterminable from potentiometric measurements. Furthermore, it was demonstrated that the acidity constants of protonated N-oxides studied in MeOH changed according to the sequence of their acidity constants in water. It was also found that in the polar solvents studied, i.e. in the amphiprotic methanol and the highly basic aprotic dimethyl sulfoxide, the cationic homo-conjugation equlibrium constants could not be determined using potentiometric method. Also, by using ab initio methods at the RHF and MP2 levels and the PCM model, utilizing the Gaussian 6-31++G** basis set, energies and Gibbs free energies of the protonation reactions of the N-oxides have been determined. The energy parameters have been compared with acidity constants of the protonated N-oxides determined by potentiometric titration in methanol to establish a correlation between these approaches.

  6. NMR study of conformational exchange and double-well proton potential in intramolecular hydrogen bonds in monoanions of succinic acid and derivatives.

    Science.gov (United States)

    Guo, Jing; Tolstoy, Peter M; Koeppe, B; Denisov, Gleb S; Limbach, Hans-Heinrich

    2011-09-08

    We present a (1)H, (2)H, and (13)C NMR study of the monoanions of succinic (1), meso- and rac-dimethylsuccinic (2, 3), and methylsuccinic (4) acids (with tetraalkylammonium as the counterion) dissolved in CDF(3)/CDF(2)Cl at 300-120 K. In all four monoanions, the carboxylic groups are linked by a short intramolecular OHO hydrogen bond revealed by the bridging-proton chemical shift of about 20 ppm. We show that the flexibility of the carbon skeleton allows for two gauche isomers in monoanions 1, 2, and 4, interconverting through experimental energy barriers of 10-15 kcal/mol (the process itself and the energy barrier are also reproduced in MP2/6-311++G** calculations). In 3, one of the gauche forms is absent because of the steric repulsion of the methyl groups. In all four monoanions, the bridging proton is located in a double-well potential and subject, at least to some extent, to proton tautomerism, for which we estimate the two proton positions to be separated by ca. 0.2 Å. In 1 and 3, the proton potential is symmetric. In 2, slowing the conformational interconversion introduces an asymmetry to the proton potential, an effect that might be strong enough even to synchronize the proton tautomerism with the interconversion of the two gauche forms. In 4, the asymmetry of the proton potential is due to the asymmetric substitution. The intramolecular H-bond is likely to remain intact during the interconversion of the gauche forms in 1, 3, and 4, whereas the situation in 2 is less clear.

  7. Substitution determination of Fmoc‐substituted resins at different wavelengths

    Science.gov (United States)

    Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

    2017-01-01

    In solid‐phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc‐substituted resins, substitution determination is often performed by suspending the Fmoc‐protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene–piperidine adduct that is quantified by ultraviolet–visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene–piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert–Beer's law, together with the substance‐specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol−1 cm−1 and 8100 l mol−1 cm−1 have been reported for the dibenzofulvene–piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. PMID:28635051

  8. Rate Constants for the Reactions of Hydroxyl Radical with Several Alkanes, Cycloalkanes, and Dimethyl Ether

    Science.gov (United States)

    DeMore, W.; Bayes, K.

    1998-01-01

    Relative rate experiements were used to measure rate constants and temperature denpendencies of the reactions of OH with propane, n-butane, n-pentane, n-hexane, cyclopropane, cyclobutane, cyclopentane, and dimethyl ether.

  9. Performance of the SMD and SM8 models for predicting solvation free energy of neutral solutes in methanol, dimethyl sulfoxide and acetonitrile

    Science.gov (United States)

    Zanith, Caroline C.; Pliego, Josefredo R.

    2015-03-01

    The continuum solvation models SMD and SM8 were developed using 2,346 solvation free energy values for 318 neutral molecules in 91 solvents as reference. However, no solvation data of neutral solutes in methanol was used in the parametrization, while only few solvation free energy values of solutes in dimethyl sulfoxide and acetonitrile were used. In this report, we have tested the performance of the models for these important solvents. Taking data from literature, we have generated solvation free energy, enthalpy and entropy values for 37 solutes in methanol, 21 solutes in dimethyl sulfoxide and 19 solutes in acetonitrile. Both SMD and SM8 models have presented a good performance in methanol and acetonitrile, with mean unsigned error equal or less than 0.66 and 0.55 kcal mol-1 in methanol and acetonitrile, respectively. However, the correlation is worse in dimethyl sulfoxide, where the SMD and SM8 methods present mean unsigned error of 1.02 and 0.95 kcal mol-1, respectively. Our results point out the SMx family of models need be improved for dimethyl sulfoxide solvent.

  10. 16,16-dimethyl prostaglandin E/sub 2/ increases survival of murine intestinal stem cells when given before photon radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, W.R.; Thomas, C.

    1983-11-01

    A variety of prostaglandins (PG) protect the gastric and intestinal mucosa when given before damaging agents as absolute ethanol, acidified taurocholate, boiling water, or nonsteroidal anti-inflammatory agents (NSAI). A synthetic prostaglandin, 16,16-dimethyl PGE/sub 2/, shown to be cytoprotective at physiologic levels to the above agents was given to mice 1 h before or 15 min after /sup 137/Cs gamma(..gamma..) whole-body irradiation. The survival of intestinal stem cells measured by their ability to form in situ colonies of regenerating epithelium was increased stem cells measured by their ability to form in situ colonies of regenerating epithelium was increased when 16,16-dimethyl PGE/sub 2/ was given before but not after /sup 137/Cs ..gamma.. irradiation. The maximum degree of 16,16-dimethyl PGE/sub 2/-induced radioprotection was seen when the drug was given 1 h before irradiation. No radioprotection was seen when the interval between drug and irradiation was 3 h or longer. When the time between 16,16-dimethyl PGE/sub 2/ and irradiation was kept at 1 h, the degree of radioprotection was dependent on the PG drug dose. There was a steep rise in the number of surviving cells at low doses of PG. These results imply that tumors which secrete PGE/sub 2/ may in part be protected from the lethal effects of ionizing photon radiation.

  11. Boltorn-Modified Poly(2,6-dimethyl-1,4,phenylene oxide) Gas Separation Membranes

    NARCIS (Netherlands)

    Sterescu, D.M.; Stamatialis, Dimitrios; Mendes, Eduardo; Kruse, Jan; Rätzke, Klaus; Faupel, Franz; Wessling, Matthias

    2007-01-01

    This paper describes the preparation, characterization and the permeation properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) dense polymer films containing aliphatic hyperbranched polyesters, Boltorn (H20, H30, and H40). The Boltorn are dispersed in PPO at various concentrations. The gas

  12. Gamma-irradiation of malic acid in aqueous solutions. [prebiotic significance

    Science.gov (United States)

    Negron-Mendoza, A.; Graff, R. L.; Ponnamperuma, C.

    1980-01-01

    The gamma-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the nonvolatile products. Thin layer chromatography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the gamma-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

  13. Performance of long straw tubes using dimethyl ether

    International Nuclear Information System (INIS)

    Benussi, L.; Bertani, M.; Bianco, S.; Fabbri, F.L.; Gianotti, P.; Giardoni, M.; Guaraldo, C.; Lanaro, A.; Lucherini, V.; Mecozzi, A.; Passamonti, L.; Russo, V.; Sarwar, S.

    1995-01-01

    A cylindrical tracking detector with an inner radius of one meter employing straw tubes is being envisaged for the FINUDA experiment aimed at hyper-nuclear physics at DAΦNE, the Frascati φ-factory. A prototype using several 10 mm and 20 mm diameter, two meter long aluminized mylar straws has been assembled and tested with a one GeV/c pion beam. While operating with dimethyl ether, gas gain, space resolution, and device systematics have been studied. A simple method of correction for systematics due to straw eccentricity has been developed and, once applied, a space resolution better than 40 μm can be reached. (orig.)

  14. Dimethyl sulfoxide (DMSO) waste residues and municipal waste water odor by dimethyl sulfide (DMS): the north-east WPCP plant of Philadelphia.

    Science.gov (United States)

    Glindemann, Dietmar; Novak, John; Witherspoon, Jay

    2006-01-01

    This study shows for the first time that overlooked mg/L concentrations of industrial dimethyl sulfoxide (DMSO) waste residues in sewage can cause "rotten cabbage" odor problems bydimethyl sulfide (DMS) in conventional municipal wastewater treatment. In laboratory studies, incubation of activated sludge with 1-10 mg/L DMSO in bottles produced dimethyl sulfide (DMS) at concentrations that exceeded the odor threshold by approximately 4 orders of magnitude in the headspace gas. Aeration at a rate of 6 m3 air/m3 sludge resulted in emission of the DMS into the exhaust air in a manner analogous to that of an activated sludge aeration tank. A field study atthe NEWPCP sewage treatment plant in Philadelphia found DMSO levels intermittently peaking as high as 2400 mg/L in sewage near an industrial discharger. After 3 h, the DMSO concentration in the influent to the aeration tank rose from a baseline level of less than 0.01 mg/L to a level of 5.6 mg/L and the DMS concentration in the mixed liquor rose from less than 0.01 to 0.2 mg/L. Finding this link between the intermittent occurrence of DMSO residues in influent of the treatment plant and the odorant DMS in the aeration tank was the keyto understanding and eliminating the intermittent "canned corn" or "rotten cabbage" odor emissions from the aeration tank that had randomly plagued this plant and its city neighborhood for two decades. Sewage authorities should consider having wastewater samples analyzed for DMSO and DMS to check for this possible odor problem and to determine whether DMSO emission thresholds should be established to limit odor generation at sewage treatment plants.

  15. Substitution determination of Fmoc-substituted resins at different wavelengths.

    Science.gov (United States)

    Eissler, Stefan; Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

    2017-10-01

    In solid-phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc-substituted resins, substitution determination is often performed by suspending the Fmoc-protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene-piperidine adduct that is quantified by ultraviolet-visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene-piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert-Beer's law, together with the substance-specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol -1  cm -1 and 8100 l mol -1  cm -1 have been reported for the dibenzofulvene-piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.

  16. Electricity/oil substitution

    International Nuclear Information System (INIS)

    Melvin, J.G.

    1980-09-01

    The extent to which electricity could substitute for imported oil in Canada is assessed and it is concluded that the bulk of projected oil imports could be displaced. This substitution of electricity for oil could be largely completed within two decades, with existing technology, using Canadian resources. The substitution of electricity for imported oil would result in relatively low energy costs and would stimulate economic growth. Energy self-sufficiency through the substitution of electricity for oil is uniquely a Canadian option; it is not open to other industrial countries. The option exists because of Canada's resources of oil sands for essential liquid fuels, hydraulic and nuclear electrical potential, and natural gas as an interim source of energy. While other countries face an energy crisis due to declining supplies of oil, Canada faces opportunities. The policies of Federal and Provincial governments, as perceived by individual decision makers, will have a major influence on Canada's ability to realize opportunities. (auth)

  17. Gamma-radiolysis of dimethyl sulfoxide. II. Radiolysis yields and possible mechanisms; Gamma-Radiolisis del dimetilsulfoxido II. Rendimientos radioloticos y posibles mecanismos

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, M C; Barrera, R

    1978-07-01

    As result of quantitative studies on gamma-radiolysis of DMSO at a dose range of 90-850 Mrads, constant G values have been obtained for the following radiolysis compounds: G(-DMSO) - 6.7 {+-}0.2; G(dimethyl sulphide) - 3.4 {+-}0.3; G(methane) - 0,75 {+-} 0.04; G(dimethyl disulphide) -0.33 {+-}0,03; G(tri methylsulphonium methanesulphonate) - 0.26 {+-} 0,01; G(methyl methanethiosulphonate) - 0,25 {+-}0.02; G(dimethyl sulphona)-0.21{+-}0.02; G(H{sub 2})-0.18{+-}0.02; and G(propane)--0.0092{+-}0.0007. Initial G values have been obtained for other identified compounds: Gi(ethane)-0,46; Gi(CO)-0.052; and Gi(CO{sub 2})-0.030. Possible mechanisms on the radiolysis process are proposed. (Author) 17 refs.

  18. Radiation cross-linking of ethylene vinyl alcohol copolymer functionalized with m-isopropenyl-α,α-dimethyl benzyl isocyanate

    International Nuclear Information System (INIS)

    Ekman, K.B.; Naesman, J.H.

    1993-01-01

    An ethylene vinyl alcohol copolymer was functionalized with m-isopropenyl-α,α-dimethyl benzyl isocyanate using reactive processing in a mixer. The functionalization introduces pendant unsaturation to the polymer, which allows radiation cross-linked to gel contents >70% at radiation doses below 100 kGy. Unfunctionalized ethylene vinyl alcohol copolymer, on the other hand, forms no gel upon irradiation. The functionalization was completed within a few minutes of reactive mixing, which was confirmed with both FTIR and 13 C-NMR measurements. The oxygen permeability of ethylene vinyl alcohol copolymer increased with increasing degree of functionalization, and irradiation of the samples formed trapped radicals, which act as oxygen scavengers. Consequently no oxygen permeability was detected. However, radical activity was inhibited by annealing the samples at 110 C resulting in a 24% higher oxygen permeability value for the irradiated unfunctionalized copolymer. The oxygen permeability values of the irradiated functionalized samples were approximately 13% lower. Laminates of m-isopropenyl-α,α-dimethyl benzyl isocyanate functionalized ethylene vinyl alcohol copolymer and m-isopropenyl-α,α-dimethyl benzyl isocyanate functionalized ethylene hydroxyethyl methacrylate copolymer acquired improved adhesive strength both at dry and wet conditions as well as at elevated temperature upon exposure to radiation

  19. Mesoporous silica materials modified with alumina polycations as catalysts for the synthesis of dimethyl ether from methanol

    Energy Technology Data Exchange (ETDEWEB)

    Macina, Daniel; Piwowarska, Zofia; Tarach, Karolina; Góra-Marek, Kinga [Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Kraków (Poland); Ryczkowski, Janusz [Maria Curie Skłodowska University, Faculty of Chemistry, Maria Curie-Skłodowska 2, 20-031 Lublin (Poland); Chmielarz, Lucjan, E-mail: chmielar@chemia.uj.edu.pl [Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Kraków (Poland)

    2016-02-15

    Highlights: • Deposition of alumina ologoctaions on mesoporous silicas modified with surface −SO{sub 3}H groups. • Alumina aggregates generated acid properties in the silica supports. • Alumina modified SBA-15 and MCF were active and selective catalysts in DME synthesis. - Abstract: Mesoporous silica materials (SBA-15 and MCF) were used as catalytic supports for the deposition of aggregated alumina species using the method consisting of the following steps: (i) anchoring 3-(mercaptopropyl)trimethoxysilane (MPTMS) on the silica surface followed by (ii) oxidation of −SH to−SO{sub 3}H groups and then (iii) deposition of aluminum Keggin oligocations by ion-exchange method and (iv) calcination. The obtained samples were tested as catalysts for synthesis of dimethyl ether from methanol. The modified silicas were characterized with respect to the ordering of their porous structure (XRD), textural properties (BET), chemical composition (EDS, CHNS), structure ({sup 27}Al NMR, FTIR) and location of alumina species (EDX-TEM), surface acidity (NH{sub 3}-TPD, Py-FTIR) and thermal stability (TGA). The obtained materials were found to be active and selective catalysts for methanol dehydration to dimethyl ether (DME) in the MTD process (methanol-to-dimethyl ether).

  20. Study on combustion characteristics of dimethyl ether under the moderate or intense low-oxygen dilution condition

    International Nuclear Information System (INIS)

    Kang, Yinhu; Lu, Tianfeng; Lu, Xiaofeng; Wang, Quanhai; Huang, Xiaomei; Peng, Shini; Yang, Dong; Ji, Xuanyu; Song, Yangfan

    2016-01-01

    Highlights: • Oxygen content in the flame base increased due to the prolonged ignition delay time. • Flow field in the furnace affected thermal/chemical structure of the flame partially. • Preheating and dilution facilitated moderate or intense low-oxygen dilution regime. • Dominant pollutant formation ways of dimethyl ether in hot dilution were clarified. • Preheating and dilution reduced nitrogen oxide emission of dimethyl ether. - Abstract: Experiments and numerical simulations were conducted in this paper to study the combustion behavior of dimethyl ether in the moderate or intense low-oxygen dilution regime, in terms of thermal/chemical structure and chemical kinetics associated with nitrogen oxide and carbon monoxide emissions. Several co-flow temperatures and oxygen concentrations were involved in the experiments to investigate their impacts on the flame behavior systematically. The results show that in the moderate or intense low-oxygen dilution regime, oxygen concentrations in the flame base slightly increased because of the prolonged ignition delay time of the reactant mixture due to oxidizer dilution, which changed the local combustion process and composition considerably. The oxidation rates of hydrocarbons were significantly depressed in the moderate or intense low-oxygen dilution regime, such that a fraction of unburned hydrocarbons at the furnace outlet were recirculated into the outer annulus of the furnace, which changed the local radial profiles of carbon monoxide, methane, and hydrogen partially. Moreover, with the increment in co-flow temperature or oxygen mole fraction, flame temperature, and hydroxyl radical, carbon monoxide, and hydrogen mole fractions across the reaction zone increased gradually. For the dimethyl ether-moderate or intense low-oxygen dilution flame, temperature homogeneity was improved at higher co-flow temperature or lower oxygen mole fraction. The carbon monoxide emission depended on the levels of temperature and

  1. Gamma radiation effects on random copolymers based on poly(butylene succinate) for packaging applications

    Science.gov (United States)

    Negrin, M.; Macerata, E.; Consolati, G.; Quasso, F.; Genovese, L.; Soccio, M.; Giola, M.; Lotti, N.; Munari, A.; Mariani, M.

    2018-01-01

    Within the context of new bioplastic materials, poly(butylene succinate) (PBS) and four novel poly(butylene/thiodiethylene succinate) random copolymers (PBS-PTDGS), in sheets as well as in films, were exposed to gamma radiation, in air and in water, and their behavior along with the effect on their biodegradability was investigated. The molecular weight data obtained from gel permeation chromatography indicate that the sensibility to radiation increases with the amount of sulfur-containing co-unit (TDGS). At 200 kGy the average molecular weight of PBS film halves, while for P(BS60TDGS40) the residual molecular weight is about 20%. The calculated intermolecular crosslink Gx and scissioning Gs yields confirmed that degradation is predominant over crosslink for all the aliphatic systems. As shown by thermal analyses, gamma radiation affects the thermal properties, leading to an increased crystallinity of the systems, remarkable for PBS, and lower decomposition temperatures. Variations of crystallinity with the increasing absorbed dose were confirmed also by PALS analyses. Water contact angle measurements revealed post-irradiation wettability alterations that could positively affect polymer biodegradability. In particular, when irradiated in water at 100 kGy PBS film exhibits a water contact angle decrease of about 17%, indicating an enhanced wettability. After degradation in compost, changes in the surface morphology were observed by means of SEM and sample weight losses were determined, at different extent, according to the irradiation environment. Interestingly, after 52 days in compost PBS films, both pristine and irradiated in air at 25 kGy, showed a residual weight of about 60%, while the ones irradiated in water at 25 kGy of about 44%. Experimental data confirmed that gamma irradiation could represent a viable treatment to enhance biodegradation in compost of PBS and PBS-based copolymers.

  2. Absolute vibrational excitation cross sections for 1-18 eV electron scattering from condensed dimethyl phosphate (DMP)

    Science.gov (United States)

    Lemelin, V.; Bass, A. D.; Wagner, J. R.; Sanche, L.

    2017-12-01

    Absolute cross sections (CSs) for vibrational excitation by 1-18 eV electrons incident on condensed dimethyl phosphate (DMP) were measured with a high-resolution electron energy loss (EEL) spectrometer. Absolute CSs were extracted from EEL spectra of DMP condensed on multilayer film of Ar held at about 20 K under ultra-high vacuum (˜1 × 10-11 Torr). Structures observed in the energy dependence of the CSs around 2, 4, 7, and 12 eV were compared with previous results of gas- and solid-phase experiments and with theoretical studies on dimethyl phosphate and related molecules. These structures were attributed to the formation of shape resonances.

  3. 2-(5,7-Dimethyl-3-methylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Hong Dae Choi

    2008-08-01

    Full Text Available The title compound, C13H14O3S, was prepared by alkaline hydrolysis of ethyl 2-(5,7-dimethyl-3-methylsulfanyl-1-benzofuran-2-ylacetate. In the crystal structure, the carboxyl groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the a axis by weak C—H...π interactions.

  4. Controls of dimethyl sulphide in the Bay of Bengal during BOBMEX-Pilot cruise 1998

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; DileepKumar, M.; Sarma, V.V.S.S

    The air-sea exchange is one of the main mechanisms maintaining the abundances of trace gases in the atmosphere. Some of these, such as carbon dioxide and dimethyl sulphide (DMS), will have a bearing on the atmospheric heat budget. While the former...

  5. Structural studies on the actinide carboxylates. 4. The crystal and molecular structure of succinate dioxouranium(VI) monohydrate

    Energy Technology Data Exchange (ETDEWEB)

    Bombieri, G; Benetollo, F [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Del Pra, A; Rojas, R

    1979-01-01

    The structure of the title compound, UO/sub 2/(CH/sub 2/COO)/sub 2/.H/sub 2/O, has been determined from three-dimensional X-ray data. The crystals are orthorhombic, space group Pbcn with four formula units in a cell. The coordination geometry about the uranium atom is pentagonal bipyramidal. The uranyl ions are equatorially surrounded by one water oxygen and by four carboxylate oxygen atoms of different succinic ligands. Each ligand is shared by four uranyl units giving rise to a polymeric-like structure.

  6. Approaches in Substitution of Organic Solvents

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    2000-01-01

    In substitution of harmful chemicals or products with less harmful or harmless ones, there are different approaches according to the different situations, the technical requirements to the substitutes, and the goals for the substitution. Three different cases are presented. The substitution process...

  7. [Effect of K-ATP channel opener-pinacidil on the liver mitochondria function in rats with different resistance to hypoxia during stress].

    Science.gov (United States)

    Tkachenko, H M; Kurhaliuk, N M; Vovkanych, L S

    2004-01-01

    We have examined the influence of ATP-sensitive potassium (KATP) channel opener pinacidil (0.06 mg/kg) and inhibitor glibenclamide (1 mg/kg) on the changes of energy metabolism in the liver of rats under the stress conditions. The rats were divided in two groups with high and low resistance to hypoxia. The stress was modeled by placing the rats in a cage filled with water and closed with a net. The distance from water to the net was only 5 cm. The effects of KATP opener pinacidil (0.06 mg/kg) and inhibitor glibenclamide (1 mg/kg) on ADP-stimulating mitochondrial respiration by Chance, calcium capacity of organellas and processes of lipid peroxidation in the liver of rats with different resistance to hypoxia under the stress condition have been investigated. We have used the next substrates of oxidation: 0.35 mM succinate and 1 mM alpha-ketoglutarate. The additional analyses were conducted with the use of inhibitors: mitochondrial enzyme complex I 10 mM rotenone and succinate dehydrohenase 2 mM malonic acid. It was shown that the stress condition evoked the succinate oxidation and the decrease of alpha-ketoglutarate efficacy, the increase of calcium mitochondrial capacity and the intensification of lipid peroxidation processes. Under the presence of succinate, the increase of O2 uptake with simultaneous decrease of ADP/O ratio in rats with high resistance under stress was observed. Simultaneously, oxidation of alpha-ketoglutarate, a NAD-dependent substrate, was inhibited. Pinacidil caused the reorganization of mitochondrial energy metabolism in favour of NAD-dependent oxidation and the improvment of the protection against stress. The decrease of the efficacy of mitochondrial energy processes functioning was shown in animals with low resistance to hypoxia. KATP channel opener pinacidil has a protective effect on the processes of mitochondrial liver energy support under stress. These changes deal with the increase of alpha-ketoglutarate oxidation (respiratory rate and

  8. Chamber simulation of photooxidation of dimethyl sulfide and isoprene in the presence of NOx

    Directory of Open Access Journals (Sweden)

    M. Jang

    2012-11-01

    Full Text Available To improve the model prediction for the formation of H2SO4 and methanesulfonic acid (MSA, aerosol-phase reactions of gaseous dimethyl sulfide (DMS oxidation products [e.g., dimethyl sulfoxide (DMSO] in aerosol have been included in the DMS kinetic model with the recently reported gas-phase reactions and their rate constants. To determine the rate constants of aerosol-phase reactions of both DMSO and its major gaseous products [e.g., dimethyl sulfone (DMSO2 and methanesulfinic acid (MSIA], DMSO was photooxidized in the presence of NOx using a 2 m3 Teflon film chamber. The rate constants tested in the DMSO kinetic mechanisms were then incorporated into the DMS photooxidation mechanism. The model simulation using the newly constructed DMS oxidation mechanims was compared to chamber data obtained from the phototoxiation of DMS in the presence of NOx. Within 120-min simulation, the predicted concentrations of MSA increase by 200–400% and those of H2SO4, by 50–200% due to aerosol-phase chemistry. This was well substantiated with experimental data. To study the effect of coexisting volatile organic compounds, the photooxidation of DMS in the presence of isoprene and NOx has been simulated using the newly constructed DMS kinetic model integrated with the Master Chemical Mechanism (MCM for isoprene oxidation, and compared to chamber data. With the high concentrations of DMS (250 ppb and isoprene (560–2248 ppb, both the model simulation and experimental data showed an increase in the yields of MSA and H2SO4 as the isoprene concentration increased.

  9. The Deletion of the Succinate Dehydrogenase Gene KlSDH1 in Kluyveromyces lactis Does Not Lead to Respiratory Deficiency

    Science.gov (United States)

    Saliola, Michele; Bartoccioni, Paola Chiara; De Maria, Ilaria; Lodi, Tiziana; Falcone, Claudio

    2004-01-01

    We have isolated a Kluyveromyces lactis mutant unable to grow on all respiratory carbon sources with the exception of lactate. Functional complementation of this mutant led to the isolation of KlSDH1, the gene encoding the flavoprotein subunit of the succinate dehydrogenase (SDH) complex, which is essential for the aerobic utilization of carbon sources. Despite the high sequence conservation of the SDH genes in Saccharomyces cerevisiae and K. lactis, they do not have the same relevance in the metabolism of the two yeasts. In fact, unlike SDH1, KlSDH1 was highly expressed under both fermentative and nonfermentative conditions. In addition to this, but in contrast with S. cerevisiae, K. lactis strains lacking KlSDH1 were still able to grow in the presence of lactate. In these mutants, oxygen consumption was one-eighth that of the wild type in the presence of lactate and was normal with glucose and ethanol, indicating that the respiratory chain was fully functional. Northern analysis suggested that alternative pathway(s), which involves pyruvate decarboxylase and the glyoxylate cycle, could overcome the absence of SDH and allow (i) lactate utilization and (ii) the accumulation of succinate instead of ethanol during growth on glucose. PMID:15189981

  10. Photoinduced electron transfer interaction of anthraquinones with aniline quenchers: Influence of methyl substitution in aniline donors

    Science.gov (United States)

    Sivakumar, V.; Ponnamma, Deepalekshmi; Hussein, Yasser H. A.

    2017-02-01

    Photoinduced electron transfer between triplet state of 9,10-anthraquinone (AQ) and its two derivatives: 2-chloro-9,10-anthraquinone (CAQ) and sodium anthraquinone-2-sulfonate (AQS) and ground state aniline (AN) and its dimethyl substitutions: 2,3-dimethylaniline (2,3-DMA), 2,6-dimethylaniline (2,6-DMA), 3,5-dimethylaniline (3,5-DMA) and N,N-dimethylaniline (N,N-DMA) is studied using nanosecond laser flash photolysis at room temperature. Detection of radical bands of quinone anions and aniline cations along with their formation and/or decay kinetics are used to confirm the electron transfer (ET) process. In MeCN medium, AN quenches the triplet state of CAQ (CAQT) but not the triplets AQT or AQST. However in aqueous medium, AN quenches AQST and forms radical ion pair. All the DMAs can react through ET with all the triplet quinones at different degrees of efficiency in MeCN medium. Noticeably, the ring substituted DMAs are less efficient in electron donation to AQT or AQST while the N,N-DMA shows high efficiency in donating electron to all triplet quinones in MeCN medium. Charge distribution of donor molecules, in MeCN medium is calculated using density functional theory (DFT), and shows an enhancement of electron density of the ring of N,N-DMA, making it an ideal electron donor for ET studies compared to other DMAs. This systematic selection and usage of anilines with electrochemically tunable quinones can be viewed as a working model of donor-acceptor system that can be utilized in photoinduced ET applications.

  11. Succinate overproduction: A case study of computational strain design using a comprehensive Escherichia coli kinetic model

    Directory of Open Access Journals (Sweden)

    Ali eKhodayari

    2015-01-01

    Full Text Available Computational strain design prediction accuracy has been the focus for many recent efforts through the selective integration of kinetic information into metabolic models. In general, kinetic model prediction quality is determined by the range and scope of genetic and/or environmental perturbations used during parameterization. In this effort, we apply the k-OptForce procedure on a kinetic model of E. coli core metabolism constructed using the Ensemble Modeling (EM method and parameterized using multiple mutant strains data under aerobic respiration with glucose as the carbon source. Minimal interventions are identified that improve succinate yield under both aerobic and anaerobic conditions to test the fidelity of model predictions under both genetic and environmental perturbations. Under aerobic condition, k-OptForce identifies interventions that match existing experimental strategies pointing at a number of unexplored flux redirections such as routing glyoxylate flux through the glycerate metabolism to improve succinate yield. Many of the identified interventions rely on the kinetic descriptions and would not be discoverable by a purely stoichiometric description. In contrast, under fermentative (anaerobic conditions, k-OptForce fails to identify key interventions including up-regulation of anaplerotic reactions and elimination of competitive fermentative products. This is due to the fact that the pathways activated under anaerobic conditions were not properly parameterized as only aerobic flux data were used in the model construction. This study shed light on the importance of condition-specific model parameterization and provides insight onto how to augment kinetic models so as to correctly respond to multiple environmental perturbations.

  12. Medicineringsfejl ved generisk substitution

    DEFF Research Database (Denmark)

    Rölfing, Jan

    2012-01-01

    Generic substitution is a major cause of medical mistakes in the general population. Danish legislation obligates pharmacies to substitute prescribed medicine with the cheapest equivalent formulation, despite variations in product name, packaging, shape and colour. Consequently, medical mistakes...... occur. Scientific evidence on the consequences of generic substitution is sparse. Call upon fellow health workers to report medical mistakes to the national entities and scientific peers, in order to increase awareness and scientific evidence about the problem....

  13. Rapid liquid–liquid extraction of thallium(III from succinate media with 2-octylaminopyridine in chloroform as the extractant

    Directory of Open Access Journals (Sweden)

    SANDIP V. MAHAMUNI

    2008-04-01

    Full Text Available A simple solvent extraction study of thallium(III was conducted. Selective and quantitative extraction of thallium(III by 2-octylaminopyridine (2-OAP in chloroform occurred from aqueous sodium succinate medium (0.0075 M at pH 3.0. Thallium(III was back extracted with acetate buffer (pH 4.63. The effect of the concentration of succinate and 2-OAP, the role of various diluents, stripping agents, loading capacity of 2-OAP, equilibrium time and aqueous:organic volume ratio on the extraction of thallium(III was studied. The stoichiometry of the extracted species was determined based on the slope analysis method and found to be 1: 2: 1 (metal:acid:extractant. The temperature dependence of the extraction equilibrium constant was also examined to estimate the apparent thermodynamic functions ∆H, ∆G and ∆S for the extraction reaction. The method is free from interference of a large number of cations and anions. The method was used for the selective extraction of thallium(III from its binary mixture with Zn(II, Cd(II, Hg(II, Bi(III, Pb(II, Se(IV, Te(IV, Sb(III, Ga(III, In(III, Al(III, Tl(I and Fe(III. The proposed method was applied to the synthetic mixtures and alloys. It is simple, selective, rapid and eco-friendly.

  14. Extraction behaviour of 2-octylaminopyridine towards lead(II) from succinate media and its separation from other toxic metals

    International Nuclear Information System (INIS)

    Mane, Chandrashekhar P.; Anuse, Mansing A.

    2008-01-01

    Liquid-liquid extraction of lead(II) from succinate media was carried out with 2-octylaminopyridine (2-OAP) in chloroform. Lead(II) was quantitatively extracted with 0.036 M 2-OAP in chloroform from 0.005-0.007 M sodium succinate when equilibrated for 5 min. Lead(II) from the organic phase was stripped with three 10 mL portions of 0.4 M acetic acid and determined titrimetrically with EDTA. The nature of extracted species was determined from the log-log plot. The optimum conditions have been evaluated based on a critical study of weak acid concentration, extractant concentration, period of equilibration and effect of diluents. The metal loading capacity of the reagent was found to be 8 mg of lead(II) with 10 mL 0.036 M of the extractant. The extraction of the lead(II) was carried out in presence of various ions to ascertain the tolerance limit of individual. Temperature dependence of the extraction equilibrium constants was examined to estimate the apparent thermodynamic functions (ΔH, ΔS and ΔG) for extraction reaction. Lead(II) was successfully separated from commonly associated metal ions such as Bi(III), Hg(II), Cr(VI), Cd(II), Zn(II), Al(III), Ca(II), Ba(II) and from binary and ternary mixtures. The method was extended for determination of lead(II) in real samples

  15. Diglycolic acid inhibits succinate dehydrogenase activity in human proximal tubule cells leading to mitochondrial dysfunction and cell death.

    Science.gov (United States)

    Landry, Greg M; Dunning, Cody L; Conrad, Taylor; Hitt, Mallory J; McMartin, Kenneth E

    2013-08-29

    Diethylene glycol (DEG) is a solvent used in consumer products allowing the increased risk for consumer exposure. DEG metabolism produces two primary metabolites, 2-hydroxyethoxyacetic acid (2-HEAA) and diglycolic acid (DGA). DGA has been shown to be the toxic metabolite responsible for the proximal tubule cell necrosis seen in DEG poisoning. The mechanism of DGA toxicity in the proximal tubule cell is not yet known. The chemical structure of DGA is very similar to citric acid cycle intermediates. Studies were designed to assess whether its mechanism of toxicity involves disruption of cellular metabolic pathways resulting in mitochondrial dysfunction. First, DGA preferentially inhibited succinate dehydrogenase, including human kidney cell enzyme, but had no effect on other citric acid cycle enzyme activities. DGA produces a cellular ATP depletion that precedes cell death. Human proximal tubule (HPT) cells, pre-treated with increasing DGA concentrations, showed significantly decreased oxygen consumption. DGA did not increase lactate levels, indicating no effect on glycolytic activity. DGA increased reactive oxygen species (ROS) production in HPT cells in a concentration and time dependent manner. These results indicate that DGA produced proximal tubule cell dysfunction by specific inhibition of succinate dehydrogenase and oxygen consumption. Disruption of these processes results in decreased energy production and proximal tubule cell death. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. Carvedilol Compared With Metoprolol Succinate in the Treatment and Prognosis of Patients With Stable Chronic Heart Failure: Carvedilol or Metoprolol Evaluation Study.

    Science.gov (United States)

    Fröhlich, Hanna; Zhao, Jingting; Täger, Tobias; Cebola, Rita; Schellberg, Dieter; Katus, Hugo A; Grundtvig, Morten; Hole, Torstein; Atar, Dan; Agewall, Stefan; Frankenstein, Lutz

    2015-09-01

    β-Blockers exert a prognostic benefit in the treatment of chronic heart failure. Their pharmacological properties vary. The only substantial comparative trial to date-the Carvedilol or Metoprolol European Trial-has compared carvedilol with short-acting metoprolol tartrate at different dose equivalents. We therefore addressed the relative efficacy of equal doses of carvedilol and metoprolol succinate on survival in multicenter hospital outpatients with chronic heart failure. Four thousand sixteen patients with stable systolic chronic heart failure who were using either carvedilol or metoprolol succinate were identified in the Norwegian Heart Failure Registry and The Heart Failure Registry of the University of Heidelberg, Germany. Patients were individually matched on both the dose equivalents and the respective propensity scores for β-blocker treatment. During a follow-up for 17 672 patient-years, it was found that 304 (27.2%) patients died in the carvedilol group and 1066 (36.8%) in the metoprolol group. In a univariable analysis of the general sample, metoprolol therapy was associated with higher mortality compared with carvedilol therapy (hazard ratio, 1.49; 95% confidence interval, 1.31-1.69; P<0.001). This difference was not seen after multivariable adjustment (hazard ratio, 0.93; 95% confidence interval, 0.57-1.50; P=0.75) and adjustment for propensity score and dose equivalents (hazard ratio, 1.06; 95% confidence interval, 0.94-1.20; P=0.36) or in the propensity and dose equivalent-matched sample (hazard ratio, 1.00; 95% confidence interval, 0.82-1.23; P=0.99). These results were essentially unchanged for all prespecified subgroups. In outpatients with chronic heart failure, no conclusive association between all-cause mortality and treatment with carvedilol or metoprolol succinate was observed after either multivariable adjustment or multilevel propensity score matching. © 2015 American Heart Association, Inc.

  17. Influence of adrenaline on the activity of succinate dehydrogenase in peripheral blood lymphocytes of irradiated rats

    International Nuclear Information System (INIS)

    Koroleva, L.V.; Vasin, M.V.

    1988-01-01

    In experiments with albino mongrel female rats, the influence of adrenaline on succinate dehydrogenase (SDG) activity in the peripheral blood lymphocytes of irradiated and intact animals has been investigated. Two minutes after the intraperitoneal administration of adrenaline (1 mg/kg) to intact rats SDG activity sharply rises and 3-4 min it drastically falls. In 6 to 8 min the second peak in the enzyme activity is registered. Twenty minutes after irradiation of rats in the crano-caudal direction with a dose of 75 Gy delivered to head, the reaction to adrenaline, manifested by the rise in SDG activity, is absent

  18. Hygroscopic Behavior of Multicomponent Aerosols Involving NaCl and Dicarboxylic Acids.

    Science.gov (United States)

    Peng, Chao; Jing, Bo; Guo, Yu-Cong; Zhang, Yun-Hong; Ge, Mao-Fa

    2016-02-25

    Atmospheric aerosols are usually complex mixtures of inorganic and organic compounds. The hygroscopicity of mixed particles is closely related to their chemical composition and interactions between components, which is still poorly understood. In this study, the hygroscopic properties of submicron particles composed of NaCl and dicarboxylic acids including oxalic acid (OA), malonic acid (MA), and succinic acid (SA) with various mass ratios are investigated with a hygroscopicity tandem differential mobility analyzer (HTDMA) system. Both the Zdanovskii-Stokes-Robinson (ZSR) method and extended aerosol inorganics model (E-AIM) are applied to predict the water uptake behaviors of sodium chloride/dicarboxylic acid mixtures. For NaCl/OA mixed particles, the measured growth factors were significantly lower than predictions from the model methods, indicating a change in particle composition caused by chloride depletion. The hygroscopic growth of NaCl/MA particles was well described by E-AIM, and that of NaCl/SA particles was dependent upon mixing ratio. Compared with model predictions, it was determined that water uptake of the NaCl/OA mixture could be enhanced and could be closer to the predictions by addition of levoglucosan or malonic acid, which retained water even at low relative humidity (RH), leading to inhibition of HCl evaporation during dehydration. These results demonstrate that the coexisting hygroscopic species have a strong influence on the phase state of particles, thus affecting chemical interactions between inorganic and organic compounds as well as the overall hygroscopicity of mixed particles.

  19. On-board conversion of methanol to dimethyl ether as an alternative diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, H; Heinzelmann, G; Struis, R; Stucki, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The catalytic dehydration of methanol to dimethyl ether was investigated for application on-board a methanol fuelled vehicle. Several catalysts have been tested in a fixed bed reactor. Our approach is to develop a small and efficient reactor converting liquid MeOH under pressure and at low reaction temperatures. (author) 2 figs., 5 refs.

  20. Solvent substitution

    International Nuclear Information System (INIS)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated