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Sample records for ethyl radicals

  1. Reactions of methyl and ethyl radicals with uranium hexafluoride

    NASA Astrophysics Data System (ADS)

    Lyman, John L.; Laguna, Glenn

    1985-01-01

    We have measured the rates of reaction of both methyl and ethyl radicals with uranium hexafluoride (UF6) in the gas phase. The method we used was to photolyze samples of UF6 in the presence of either methane or ethane. The radicals produced by reaction of fluorine atoms with these species then react with either themselves or with UF6. We inferred the rate constants from ratios of the reaction products and the published rate constants for radical recombination. The diagnostic technique was gas chromatography. The resulting rate constants for reaction with UF6 were (1.6±0.8)×10-14 cm3 molecule-1 s-1 for methyl radicals and (4±2)×10-11 cm3 molecule-1 s-1 for ethyl radicals.

  2. Dissociation of the Ethyl Radical: An Exercise in Computational Chemistry

    ERIC Educational Resources Information Center

    Nassabeh, Nahal; Tran, Mark; Fleming, Patrick E.

    2014-01-01

    A set of exercises for use in a typical physical chemistry laboratory course are described, modeling the unimolecular dissociation of the ethyl radical to form ethylene and atomic hydrogen. Students analyze the computational results both qualitatively and quantitatively. Qualitative structural changes are compared to approximate predicted values…

  3. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  4. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface.

  5. Phenacyl Ethyl Carbazolium as a Long Wavelength Photoinitiator for Free Radical Polymerization.

    PubMed

    Kara, Merve; Dadashi-Silab, Sajjad; Yagci, Yusuf

    2015-12-01

    A new phenacyl-type photoinitiator based on ethyl carbazole as a long wavelength photo-initiator is developed for free radical polymerization. Phenacyl ethyl carbazolium hexafluoroantimonate (PECH) photoinitiator is synthesized in a two-step, one-pot manner by quaternizing ethyl carbazole with phenacyl bromide and subsequent ion exchange reaction with potassium hexafluoroantimonate. Under irradiation, PECH tends to undergo homolytic bond cleavage bringing about initiating free radicals. However, as evidenced by cyclic voltammetry and real-time photobleaching studies, formation of initiating cationic species is highly unlikely as the photochemically formed charged carbazole units tend to couple. PMID:26356628

  6. Ethyl radical ejection during photodecomposition of butanone on TiO 2(1 1 0)

    NASA Astrophysics Data System (ADS)

    Henderson, Michael A.

    2008-10-01

    The photodecomposition of acetone and butanone were examined on the (1 1 0) surface of rutile TiO 2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was preceded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in an adsorbed diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater stability of the C-CH 3 bond in butanone over that of the C-C 2H 5 bond. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO 2(1 1 0) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed preference for dehydrogenation to ethene on the surface through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO 2 surface.

  7. Degradation of methyl and ethyl mercury into inorganic mercury by oxygen free radical-producing systems: involvement of hydroxyl radical.

    PubMed

    Suda, I; Totoki, S; Takahashi, H

    1991-01-01

    Degradation of methyl mercury (MeHg) and ethyl Hg (EtHg) with oxygen free radicals was studied in vitro by using three well-known hydroxyl radical (.OH)-producing systems, namely Cu2(+)-ascorbate, xanthine oxidase (XOD)-hypoxanthine (HPX)-Fe(III)EDTA and hydrogen peroxide (H2O2)-ultraviolet light B. For this purpose, the direct determination method for inorganic Hg was employed. MeHg and EtHg were readily degraded by these three systems, though the amounts of inorganic Hg generated from MeHg were one half to one third those from EtHg. Degradation activity of XOD-HPX-Fe(III)EDTA system was inhibited by superoxide dismutase, catalase and the .OH scavengers and stimulated by H2O2. Deletion of the .OH formation promoter Fe(III)EDTA from XOD-HPX-Fe(III)EDTA system resulted in the decreased degradation of MeHg and EtHg, which was enhanced by further addition of the iron chelator diethylenetriamine pentaacetic acid. In all these cases, a good correlation was observed between alkyl Hg degradation and deoxyribose oxidation determining .OH. By contrast, their degradation appeared to be unrelated to either superoxide anion (O2-) production or H2O2 production alone. We further confirmed that H2O2 (below 2 mM) itself did not cause significant degradation of MeHg and EtHg. These results suggested that .OH, but not O2- and H2O2, might be the oxygen free radical mainly responsible for the degradation of MeHg and EtHg. PMID:1647758

  8. Consecutive radical S-adenosylmethionine methylations form the ethyl side chain in thienamycin biosynthesis.

    PubMed

    Marous, Daniel R; Lloyd, Evan P; Buller, Andrew R; Moshos, Kristos A; Grove, Tyler L; Blaszczyk, Anthony J; Booker, Squire J; Townsend, Craig A

    2015-08-18

    Despite their broad anti-infective utility, the biosynthesis of the paradigm carbapenem antibiotic, thienamycin, remains largely unknown. Apart from the first two steps shared with a simple carbapenem, the pathway sharply diverges to the more structurally complex members of this class of β-lactam antibiotics, such as thienamycin. Existing evidence points to three putative cobalamin-dependent radical S-adenosylmethionine (RS) enzymes, ThnK, ThnL, and ThnP, as potentially being responsible for assembly of the ethyl side chain at C6, bridgehead epimerization at C5, installation of the C2-thioether side chain, and C2/3 desaturation. The C2 substituent has been demonstrated to be derived by stepwise truncation of CoA, but the timing of these events with respect to C2-S bond formation is not known. We show that ThnK of the three apparent cobalamin-dependent RS enzymes performs sequential methylations to build out the C6-ethyl side chain in a stereocontrolled manner. This enzymatic reaction was found to produce expected RS methylase coproducts S-adenosylhomocysteine and 5'-deoxyadenosine, and to require cobalamin. For double methylation to occur, the carbapenam substrate must bear a CoA-derived C2-thioether side chain, implying the activity of a previous sulfur insertion by an as-yet unidentified enzyme. These insights allow refinement of the central steps in complex carbapenem biosynthesis. PMID:26240322

  9. Consecutive radical S-adenosylmethionine methylations form the ethyl side chain in thienamycin biosynthesis

    PubMed Central

    Marous, Daniel R.; Lloyd, Evan P.; Buller, Andrew R.; Moshos, Kristos A.; Grove, Tyler L.; Blaszczyk, Anthony J.; Booker, Squire J.; Townsend, Craig A.

    2015-01-01

    Despite their broad anti-infective utility, the biosynthesis of the paradigm carbapenem antibiotic, thienamycin, remains largely unknown. Apart from the first two steps shared with a simple carbapenem, the pathway sharply diverges to the more structurally complex members of this class of β-lactam antibiotics, such as thienamycin. Existing evidence points to three putative cobalamin-dependent radical S-adenosylmethionine (RS) enzymes, ThnK, ThnL, and ThnP, as potentially being responsible for assembly of the ethyl side chain at C6, bridgehead epimerization at C5, installation of the C2-thioether side chain, and C2/3 desaturation. The C2 substituent has been demonstrated to be derived by stepwise truncation of CoA, but the timing of these events with respect to C2–S bond formation is not known. We show that ThnK of the three apparent cobalamin-dependent RS enzymes performs sequential methylations to build out the C6-ethyl side chain in a stereocontrolled manner. This enzymatic reaction was found to produce expected RS methylase coproducts S-adenosylhomocysteine and 5′-deoxyadenosine, and to require cobalamin. For double methylation to occur, the carbapenam substrate must bear a CoA-derived C2-thioether side chain, implying the activity of a previous sulfur insertion by an as-yet unidentified enzyme. These insights allow refinement of the central steps in complex carbapenem biosynthesis. PMID:26240322

  10. Rapid syntheses of dehydrodiferulates via biomimetic radical coupling reactions of ethyl ferulate.

    PubMed

    Lu, Fachuang; Wei, Liping; Azarpira, Ali; Ralph, John

    2012-08-29

    Dehydrodimerization of ferulates in grass cell walls provides a pathway toward cross-linking polysaccharide chains limiting the digestibility of carbohydrates by ruminant bacteria and in general affecting the utilization of grass as a renewable bioresource. Analysis of dehydrodiferulates (henceforth termed diferulates) in plant cell walls is useful in the evaluation of the quality of dairy forages as animal feeds. Therefore, there has been considerable demand for quantities of diferulates as standards for such analyses. Described here are syntheses of diferulates from ethyl ferulate via biomimetic radical coupling reactions using the copper(II)-tetramethylethylenediamine [CuCl(OH)-TMEDA] complex as oxidant or catalyst. Although CuCl(OH)-TMEDA oxidation of ethyl ferulate in acetonitrile produced mixtures composed of 8-O-4-, 8-5-, 8-8- (cyclic and noncyclic), and 5-5-coupled diferulates, a catalyzed oxidation using CuCl(OH)-TMEDA as catalyst and oxygen as an oxidant resulted in better overall yields of such diferulates. Flash chromatographic fractionation allowed isolation of 8-8- and 5-5-coupled diferulates. 8-5-Diferulate coeluted with 8-O-4-diferulate but was separated from it via crystallization; the 8-O-4 diferulate left in the mother solution was isolated by rechromatography following a simple tetrabutylammonium fluoride treatment that converted 8-5-diferulate to another useful diferulate, 8-5-(noncyclic) diferulate. Therefore, six of the nine (5-5, 8-O-4, 8-5-c, 8-5-nc, 8-5-dc, 8-8-c, 8-8-nc, 8-8-THF, 4-O-5) diferulic acids that have to date been found in the alkaline hydrolysates of plant cell walls can be readily synthesized by the CuCl(OH)-TMEDA catalyzed aerobic oxidative coupling reaction and subsequent saponification described here. PMID:22846085

  11. The carbomethylation of arylacrylamides leading to 3-ethyl-3-substituted indolin-2-one by cascade radical addition/cyclization.

    PubMed

    Dai, Qiang; Yu, Jintao; Jiang, Yan; Guo, Songjin; Yang, Haitao; Cheng, Jiang

    2014-04-14

    An FeCl2-promoted carbomethylation of arylacrylamides by di-tert-butyl peroxide (DTBP) is achieved, leading to 3-ethyl-3-substituted indolin-2-one in high yield. The reaction tolerates a series of functional groups, such as cyano, nitro, ethyloxy carbonyl, bromo, chloro, and trifluoromethyl groups. The radical methylation and arylation of the alkenyl group are involved in this reaction. PMID:24589915

  12. The photodissociation dynamics of the ethyl radical, C{sub 2}H{sub 5}, investigated by velocity map imaging

    SciTech Connect

    Steinbauer, Michael; Giegerich, Jens; Fischer, Kathrin H.; Fischer, Ingo

    2012-07-07

    The photodissociation dynamics of the ethyl radical C{sub 2}H{sub 5} has been investigated by velocity map imaging. Ethyl was produced by flash pyrolysis from n-propyl nitrite and excited to the A {sup 2}A{sup Prime} (3s) Rydberg state around 250 nm. The energetically most favorable reaction channel in this wavelength region is dissociation to C{sub 2}H{sub 4} (ethene) + H. The H-atom dissociation products were ionized in a [1+1{sup Prime }] process via the 1s-2p transition. The observed translational energy distribution is bimodal: A contribution of slow H-atoms with an isotropic angular distribution peaks at low translational energies. An expectation value for the fraction of excess energy released into translation of = 0.19 is derived from the data, typical for statistical dissociation reactions. In addition, a fast H-atom channel is observed, peaking around 1.8 eV. The latter shows an anisotropic distribution with {beta}= 0.45. It originates from a direct dissociation process within less than a rotational period. Time-delay scans with varying extraction voltages indicate the presence of two rates for the formation of H-atoms. One rate with a sub-nanosecond time constant is associated with H-atoms with large translational energy; a second one with a time constant on the order of 100 ns is associated with H-atoms formed with low translational energy. The data confirm and extend those from previous experiments and remove some inconsistencies. Possible mechanisms for the dissociation are discussed in light of the new results as well as previous ones.

  13. Kinetic study of the reaction of the hydroxyl radical (OH) with methyl ethyl ketone (2-butanone) and its deuterated isotopomers at low pressure

    NASA Astrophysics Data System (ADS)

    Liljegren, J. A.; Stevens, P. S.

    2012-12-01

    Methyl ethyl ketone (2-butanone) in the atmosphere comes from a variety of sources. It is produced commercially as an industrial ketone. It can be formed as a result of the OH or Cl-initiated oxidation of C4-C6 alkanes, primarily n-butane, or from the reaction of some alkenes with OH or O3. Biogenic sources include direct emissions from certain plants as well as emissions from decaying plant matter. Methyl ethyl ketone is removed from the atmosphere primarily by its reaction with OH. A product of this reaction includes acetaldehyde, which is a hazardous air pollutant, can further react to produce peroxy acetyl nitrate (PAN), and can be a significant source of free radicals to the atmosphere. The absolute rate constant for the reaction of OH with methyl ethyl ketone has been measured as a function of temperature at low pressure using discharge-flow techniques coupled with laser induced fluorescence (LIF) detection of OH. In addition, measurements of the rate constants for the reactions of OH with two deuterated isotopomers of methyl ethyl ketone, including CD3C(O)CH2CH3 and CH3C(O)CD2CD3, will be presented to gain a better understanding of the mechanism for this reaction. Theoretical studies of the potential energy surface for this reaction suggest that the reaction proceeds through the formation of a hydrogen-bonded pre-reactive complex, similar to that of several other atmospherically relevant oxygenated VOCs such as acetone, acetic acid, and hydroxyacetone.

  14. Icosapent Ethyl

    MedlinePlus

    ... weight loss, exercise) to reduce the amount of triglycerides (a fat-like substance) in your blood. Icosapent ... ethyl may work by decreasing the amount of triglycerides and other fats made in the liver.

  15. Ethyl carbamate

    Integrated Risk Information System (IRIS)

    Ethyl carbamate ; CASRN 51 - 79 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  16. Ethyl chloride

    Integrated Risk Information System (IRIS)

    Ethyl chloride ; CASRN 75 - 00 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  17. Ethyl ether

    Integrated Risk Information System (IRIS)

    Ethyl ether ; CASRN 60 - 29 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  18. Ethyl acetate

    Integrated Risk Information System (IRIS)

    Ethyl acetate ; CASRN 141 - 78 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  19. Radical prostatectomy

    MedlinePlus

    Prostatectomy - radical; Radical retropubic prostatectomy; Radical perineal prostatectomy; Laparoscopic radical prostatectomy; LRP; Robotic-assisted laparoscopic prostatectomy; RALP; Pelvic lymphadenectomy; ...

  20. FTIR gas-phase kinetic study on the reactions of OH radicals and Cl atoms with unsaturated esters: Methyl-3,3-dimethyl acrylate, (E)-ethyl tiglate and methyl-3-butenoate

    NASA Astrophysics Data System (ADS)

    Colomer, Juan P.; Blanco, María B.; Peñéñory, Alicia B.; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A.

    2013-11-01

    The relative-rate technique has been used to obtain rates coefficients for the reactions of the unsaturated esters methyl-3,3-dimethyl acrylate, (E)-ethyl tiglate and methyl-3-butenoate with OH radicals and chlorine atoms at (298 ± 2) K in synthetic air at a total pressure of (760 ± 10) Torr. The experiments were performed in an environmental chamber using in situ FTIR detection to monitor the decay of the esters relative to different reference compounds. The following room temperature rate coefficients (in units of cm3 molecule-1 s-1) were obtained: k1(OH + (CH3)2Cdbnd CHC(O)OCH3) = (4.46 ± 1.05) × 10-11, k2(Cl + (CH3)2Cdbnd CHC(O)OCH3) = (2.78 ± 0.46) × 10-10, k3(OH + CH3CHdbnd C(CH3)C(O)OCH2CH3) = (8.32 ± 1.93) × 10-11, k4(Cl + CH3CHdbnd C(CH3)C(O)OCH2CH3) = (2.53 ± 0.35) × 10-10, k5(OH + CH2dbnd CHCH2C(O)OCH3) = (3.16 ± 0.57) × 10-11, k4(Cl + CH2dbnd CHCH2C(O)OCH3) = (2.10 ± 0.35) × 10-10. With the exception of the reaction of Cl with methyl-3,3-dimethyl acrylate (k2), for which one determination exists in the literature, this study is the first kinetic study for these reactions under atmospheric pressure. Reactivity trends are discussed in terms of the effect of the alkyl and ester groups attached to the double bond on the overall rate coefficients towards OH radicals. The atmospheric implications of the reactions were assessed by the estimation of the tropospheric lifetimes of the title reactions.

  1. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ethyl alcohol containing ethyl acetate....

  2. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ethyl alcohol containing ethyl acetate....

  3. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ethyl alcohol containing ethyl acetate....

  4. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl alcohol containing ethyl acetate....

  5. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ethyl alcohol containing ethyl acetate....

  6. Chlorimuron-ethyl

    Integrated Risk Information System (IRIS)

    Chlorimuron - ethyl ; CASRN 90982 - 32 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  7. Methyl ethyl ketone (MEK)

    Integrated Risk Information System (IRIS)

    Methyl ethyl ketone ( MEK ) ( CASRN 78 - 93 - 3 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonc

  8. Ethyl alcohol production

    SciTech Connect

    Hofman, V.; Hauck, D.

    1980-11-01

    Recent price increases and temporary shortages of petroleum products have caused farmers to search for alternate sources of fuel. The production of ethyl alcohol from grain is described and the processes involved include saccharification, fermentation and distillation. The resulting stillage has potential as a livestock feed.

  9. Reactivity of 2-ethyl-1-hexanol in the atmosphere.

    PubMed

    Gallego-Iniesta García, María Paz; Moreno Sanroma, Alberto; Martín Porrero, María Pilar; Tapia Valle, Araceli; Cabañas Galán, Beatriz; Salgado Muñoz, María Sagrario

    2010-04-01

    Rate coefficients at room temperature for the reaction of 2-ethyl-1-hexanol with OH and NO(3) radicals and with Cl atoms have been determined in a 150 L PTFE chamber using GC-FID/SPME and FTIR as detection systems. The rate coefficients k (in units of cm(3) molecule(-1) s(-1)) obtained were: (1.13 +/- 0.31) 10(-11) for the OH reaction, (2.93 +/- 0.92) 10(-15) for the NO(3) reaction and (1.88 +/- 0.25) 10(-10) for the Cl reaction. Despite the high concentrations of 2-ethyl-1-hexanol, especially in indoor air, this is the first kinetic study carried out to date for these reactions. The results are consistent with the expected reactivity given the chemical structure of 2-ethyl-1-hexanol. Calculated atmospheric lifetimes reveal that the dominant loss process for 2-ethyl-1-hexanol is clearly the daytime reaction with the hydroxyl radical. PMID:20237722

  10. ESR of the cation radicals from γ-irradiated ketenes in haloalkane and SF 6 matrices

    NASA Astrophysics Data System (ADS)

    Shimokoshi, Kazuo; Fujisawa, Jun; Nakamura, Kazutaka; Sato, Shin; Shida, Tadamasa

    1983-08-01

    The cation radicals of ketene and its methyl and ethyl derivatives have been produced in γ-irradiated solid solutions of haloalkanes and SF 6. From the observed isotropic proton hyperfine parameters of these cation radicals and UHF MO (INDO) calculations, the cations are found to be characteristic of ordinary π-radicals.

  11. Radical Hysterectomy

    MedlinePlus

    ... the base of her partner’s penis during intercourse. Orgasm after radical hysterectomy Women who have had a ... the surgery will affect their ability to have orgasms. This has not been studied a great deal, ...

  12. Detection of interstellar ethyl cyanide

    NASA Technical Reports Server (NTRS)

    Johnson, D. R.; Lovas, F. J.; Gottlieb, C. A.; Gottlieb, E. W.; Litvak, M. M.; Thaddeus, P.; Guelin, M.

    1977-01-01

    Twenty-four millimeter-wave emission lines of ethyl cyanide (CH3CH2CN) have been detected in the Orion Nebula (OMC-1) and seven in Sgr B2. To derive precise radial velocities from the astronomical data, a laboratory measurement of the rotational spectrum of ethyl cyanide has been made at frequencies above 41 GHz. In OMC-1, the rotational temperature of ethyl cyanide is 90 K (in good agreement with other molecules), the local-standard-of-rest radial velocity is 4.5 + or - 1.0 km/s (versus 8.5 km/s for most molecules), and the column density is 1.8 by 10 to the 14th power per sq cm (a surprisingly high figure for a complicated molecule). The high abundance of ethyl cyanide in the Orion Nebula suggests that ethane and perhaps larger saturated hydrocarbons may be common constituents of molecular clouds and have escaped detection only because they are nonpolar or only weakly polar.

  13. S-Ethyl dipropylthiocarbamate (EPTC)

    Integrated Risk Information System (IRIS)

    S - Ethyl dipropylthiocarbamate ( EPTC ) ; CASRN 759 - 94 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessme

  14. Roaming Radicals

    NASA Astrophysics Data System (ADS)

    Bowman, Joel M.; Shepler, Benjamin C.

    2011-05-01

    Roaming is a recently verified unusual pathway to molecular products from unimolecular dissociation of an energized molecule. Here we present the evidence for this pathway for H2CO and CH3CHO. Theoretical analysis shows that this path visits the plateau region of the potential energy surface near dissociation to radical products. It is not clear whether roaming is a distinct isolated pathway, in addition to the conventional one via the well-known molecular saddle-point transition state. Evidence is presented to suggest that the two pathways may originate from a single, but highly complicated, dividing surface. Other examples of unusual reaction dynamics are also reviewed.

  15. Radical-initiated reaction of methyl linoleate with dialkyl phosphites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The addition of dialkyl phosphite (methyl, ethyl and n-butyl) to methyl linoleate (MeLin) double bonds was investigated. The reaction proved to be more challenging than the analogous reaction with methyl oleate (MeOl), due to inhibition of the radical reaction by the bis-allylic hydrogens of MeLin a...

  16. Wheat Seedlings as Food Supplement to Combat Free Radicals: An In Vitro Approach

    PubMed Central

    Ravikumar, P.; Shalini, G.; Jeyam, M.

    2015-01-01

    The present study was designed to evaluate the antioxidant activity of 5 organic solvent extracts (petroleum ether, n-hexane, chloroform, ethyl acetate and methanol) of wheat grains, 3, 5 and 7 days old wheat seedlings. To determine the antioxidant activity of five extracts of four different samples, 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, total phenolic content and ferrous reducing power ability were carried out. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging effect of chloroform and ethyl acetate extracts of 3 days old wheat seedlings was higher than wheat grains. Chloroform, ethyl acetate and methanol extracts of 3 days old wheat seedlings exhibited higher 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging effcet than extracts of other samples. The phenolic content was high in chloroform, ethyl acetate and methanol extract of 5 days old wheat seedlings. When compared with wheat grain, reducing power ability was high in chloroform, ethyl acetate and methanol extract of wheat seedlings, especially in 3 and 5 days old wheat seedlings. From the above results, it was concluded that chloroform, ethyl acetate and methanol extract of 3, 5 and 7 days old wheat seedlings showed better antioxidant activity than the wheat grain extracts. Hence, the results of the present study suggest the intake of wheat seedlings as a food supplement to combat the diseases caused by free radicals. PMID:26798175

  17. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, Box... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and....1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH. (b) The ingredient meets...

  18. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  19. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  20. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  1. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  2. Hydrogenation of ethyl 5-cyano-2-oximinovalerate

    SciTech Connect

    Klabunovskii, E.I.; Levitina, E.S.; Kaigorodova, L.N.; Godunova, L.F.; Gogoladze, D.D.; Karpeiskaya, E.I.; Novikova, S.A.

    1987-03-10

    Hydrogenation of ethyl 5-cyano-2-oximinovalerate in acetic anhydride at atmospheric pressure in the presence of strong base leads to a quantitative yield of the ethyl ester of ..cap alpha..,eta-diacetyllysine. Selective reduction of the cyano and oximino groups in ethyl 5-cyano-2-oximinovalerate has been shown in the presence of powdered Ni, Cu-Ni, and LaNi/sub 5/H/sub 6.6/ catalysts. Hydrogenation of ethyl 5-cyano-2-oximinovalerate on Raney Ni at atmospheric pressure in dioxan with addition of acetic anhydride leads to a 50% yield of diacetyllysine.

  3. Characterization and Antioxidant Properties of Six Algerian Propolis Extracts: Ethyl Acetate Extracts Inhibit Myeloperoxidase Activity

    PubMed Central

    Boufadi, Yasmina Mokhtaria; Soubhye, Jalal; Riazi, Ali; Rousseau, Alexandre; Vanhaeverbeek, Michel; Nève, Jean; Boudjeltia, Karim Zouaoui; Van Antwerpen, Pierre

    2014-01-01

    Because propolis contains many types of antioxidant compounds such as polyphenols and flavonoids, it can be useful in preventing oxidative damages. Ethyl acetate extracts of propolis from several Algerian regions show high activity by scavenging free radicals, preventing lipid peroxidation and inhibiting myeloperoxidase (MPO). By fractioning and assaying ethyl acetate extracts, it was observed that both polyphenols and flavonoids contribute to these activities. A correlation was observed between the polyphenol content and the MPO inhibition. However, it seems that kaempferol, a flavonoid, contributes mainly to the MPO inhibition. This molecule is in a high amount in the ethyl acetate extract and demonstrates the best efficiency towards the enzyme with an inhibiting concentration at 50% of 4 ± 2 μM. PMID:24514562

  4. Characterization and antioxidant properties of six Algerian propolis extracts: ethyl acetate extracts inhibit myeloperoxidase activity.

    PubMed

    Boufadi, Yasmina Mokhtaria; Soubhye, Jalal; Riazi, Ali; Rousseau, Alexandre; Vanhaeverbeek, Michel; Nève, Jean; Boudjeltia, Karim Zouaoui; Van Antwerpen, Pierre

    2014-01-01

    Because propolis contains many types of antioxidant compounds such as polyphenols and flavonoids, it can be useful in preventing oxidative damages. Ethyl acetate extracts of propolis from several Algerian regions show high activity by scavenging free radicals, preventing lipid peroxidation and inhibiting myeloperoxidase (MPO). By fractioning and assaying ethyl acetate extracts, it was observed that both polyphenols and flavonoids contribute to these activities. A correlation was observed between the polyphenol content and the MPO inhibition. However, it seems that kaempferol, a flavonoid, contributes mainly to the MPO inhibition. This molecule is in a high amount in the ethyl acetate extract and demonstrates the best efficiency towards the enzyme with an inhibiting concentration at 50% of 4 ± 2 µM. PMID:24514562

  5. Synthesis, Structural and Antioxidant Studies of Some Novel N-Ethyl Phthalimide Esters

    PubMed Central

    Chandraju, Siddegowda; Win, Yip-Foo; Tan, Weng Kang; Quah, Ching Kheng; Fun, Hoong-Kun

    2015-01-01

    A series of N-ethyl phthalimide esters 4(a-n) were synthesized and characterized by spectroscopic studies. Further, the molecular structure of majority of compounds were analysed by single crystal X-ray diffraction studies. The X-ray analysis revealed the importance of substituents on the crystal stability and molecular packing. All the synthesized compounds were tested for in vitro antioxidant activity by DPPH radical scavenging, FRAP and CUPRAC methods. Few of them have shown good antioxidant activity. PMID:25742494

  6. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  7. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  8. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  9. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  10. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  11. 21 CFR 172.868 - Ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl cellulose. 172.868 Section 172.868 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.868 Ethyl...

  12. 21 CFR 172.868 - Ethyl cellulose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl cellulose. 172.868 Section 172.868 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.868 Ethyl...

  13. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  14. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  15. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  16. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  17. Formation and inhibition of ethyl glucuronide and ethyl sulfate.

    PubMed

    Stachel, Nicole; Skopp, Gisela

    2016-08-01

    Ethyl glucuronide (EtG) und ethyl sulfate (EtS) are widely accepted biomarkers in forensic and clinical settings. Even though, levels of EtG and EtS in blood and urine increase with increasing doses of alcohol, a high inter-individual variability in their production has been noticed. Therefore, we investigated the influence of dietary plant phenols on the formation of EtG and EtS and tentatively estimated the magnitude of in vivo inhibitory interactions from our in vitro results. To address these issues, formation of EtS and EtG was investigated using recombinant glucuronosyl- and sulfotransferases as well as human liver microsomes and liver cytosol. After respective kinetics had been established, inhibition experiments using quercetin, kaempferol and resveratrol were performed. These polyphenols are subject to extensive glucuronidation and/or sulfonation. EtG and EtS were determined by LC-MS/MS following solid phase extraction for EtG due to severe matrix effects and by direct injection for EtS. All enzymes investigated were involved in the conjugation of ethanol. Maximal EtG and EtS formation rates were observed with HLM and SULT1A1, respectively. All kinetics could best be described by Michaelis-Menten kinetics. Resveratrol was a competitive inhibitor of UGT1A1, UGT1A9 and HLM; quercetin and kaempferol were inhibitors of all transferases under investigation except UGT2B15. Findings for quercetin with regard to UGT2B7 and SULT2A1 and for kaempferol with regard to SULT1E1 and SULT2A1 suggested a mechanism based inhibition. Competitive inhibition of the glucuronidation and sulfonation of ethanol was estimated as weak to negligible and as moderate to weak, respectively. Beside the known polymorphisms of the transferases involved in EtG and EtS formation, prediction of the inhibitory potential indicates that polyphenols may contribute to the variable formation rate of EtG and EtS. PMID:26829336

  18. Rate Constant and Temperature Dependence for the Reaction of Hydroxyl Radicals with 2-Flouropropane (FC-281ea) and Comparison with an Estimated Rate Constant

    NASA Technical Reports Server (NTRS)

    DeMore, W.; Wilson, E., Jr.

    1998-01-01

    Relative rate experiments were used to measure the rate constant and temperature dependence of the reaction of OH radicals with 2-fluoropropane (HFC-281ea), using ethane, propane, ethyl chloride as reference standards.

  19. Structure and reactions of cation-radicals of esters in freon matrices

    SciTech Connect

    Belevskii, V.N.; Belopushkin, S.I.; Fel'dman, V.I.

    1987-11-01

    In CFCl/sub 3/ matrices the cation-radicals of methyl and ethyl formates, formed in ..gamma..-irradiated solutions, at 77 K efficiently undergo intramolecular H atom transfer to form the secondary cation-radicals HC(OH)OCH/sub 2/CH/sub 2/ and DC(OH)OCD/sub 2/CH/sub 2/. This process does not occur in the deuteroformate cation-radical DCOOCH/sub 2/CD/sub 3//sup +./, which is observed in the ESR spectra in different conformations, depending on the temperature. Ion-molecule reactions involving cation-radicals are indicated

  20. Radical prostatectomy - discharge

    MedlinePlus

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

  1. Sunlight and free radicals

    NASA Astrophysics Data System (ADS)

    Tidwell, Thomas

    2013-08-01

    Thomas Tidwell reflects on the overlooked -- but prescient -- proposal by the British chemists Arthur Downes and Thomas Blunt for photochemical free-radical formation, decades before Moses Gomberg launched the field of radical chemistry by preparing triphenylmethyl, the first stable organic radical.

  2. Process for the preparation of ethyl benzene

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1995-12-19

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50 C to 300 C, using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered. 2 figs.

  3. Process for the preparation of ethyl benzene

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1995-01-01

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50.degree. C. to 300.degree. C., using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered.

  4. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... of concentrated sulfuric acid. Ethyl formate occurs naturally in some plant oils, fruits, and juices but does not occur naturally in the animal kingdom. (b) The ingredient meets the specifications of...

  5. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Ethyl formate occurs naturally in some plant oils, fruits, and juices but does not occur naturally in the animal kingdom. (b) The ingredient meets the specifications of the “Food Chemicals Codex,” 3d...

  6. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of concentrated sulfuric acid. Ethyl formate occurs naturally in some plant oils, fruits, and juices but does not occur naturally in the animal kingdom. (b) The ingredient meets the specifications of...

  7. Antioxidant and Protective Effect of Ethyl Acetate Extract of Podophyllum Hexandrum Rhizome on Carbon Tetrachloride Induced Rat Liver Injury

    PubMed Central

    Ganie, Showkat Ahmad; Haq, Ehtishamul; Masood, Akbar; Hamid, Abid; Zargar, Mohmmad Afzal

    2011-01-01

    The antioxidant and hepatoprotective activities of ethyl acetate extract was carefully investigated by the methods of DPPH radical scavenging activity, Hydroxyl radical scavenging activity, Superoxide radical scavenging activity, Hydrogen peroxide radical scavenging activity and its Reducing power ability. All these in vitro antioxidant activities were concentration dependent which were compared with standard antioxidants such as BHT, α-tocopherol. The hepatoprotective potential of Podophyllum hexandrum extract was also evaluated in male Wistar rats against carbon tetrachloride (CCl4)-induced liver damage. Pre-treated rats were given ethyl acetate extract at 20, 30 and 50 mg/kg dose prior to CCl4 administration (1 ml/kg, 1:1 in olive oil). Rats pre-treated with Podophyllum hexandrum extract remarkably prevented the elevation of serum AST, ALT, LDH and liver lipid peroxides in CCl4-treated rats. Hepatic glutathione levels were significantly increased by the treatment with the extract in all the experimental groups. The extract at the tested doses also restored the levels of liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione-S- transferase) significantly. This study suggests that ethyl acetate extract of P. hexandrum has a liver protective effect against CCl4-induced hepatotoxicity and possess in vitro antioxidant activities. PMID:21394192

  8. 40 CFR 721.10595 - Octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Octadecen-1-aminium, N-ethyl-N,N... Significant New Uses for Specific Chemical Substances § 721.10595 Octadecen-1-aminium, N-ethyl-N,N-dimethy... chemical substance identified as octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1) (PMN...

  9. Synthesis of functionalized 5-substituted thiazolidine-2-thiones via adscititious xanthate-promoted radical cyclization of allyl(alkyl/aryl)dithiocarbamates.

    PubMed

    Gao, Simiao; Zhang, Yu; Dong, Jun; Chen, Ning; Xu, Jiaxi

    2016-01-21

    Functionalized 5-substituted thiazolidine-2-thiones were synthesized efficiently from alkyl allyl(alkyl/aryl)-dithiocarbamates via radical cyclization with the corresponding S-alkyl O-ethyl xanthates as the adscititious radical precursors. The application of the adscititious radical precursors improves not only the yields, but also the efficiency in the radical cyclization reaction significantly. The current adscititious radical precursor method provides a new strategy for the achievement and improvement of some radical reactions which are hardly or difficultly realized by the traditional direct methods. PMID:26626401

  10. Decontamination of 2-Chloroethyl Ethyl Sulfide by Pulsed Corona Plasma

    NASA Astrophysics Data System (ADS)

    Li, Zhanguo; Hu, Zhen; Cao, Peng; Zhao, Hongjie

    2014-11-01

    Decontamination of 2-chloroethyl ethyl sulfide (2-CEES, CH3CH2SCH2CH2Cl) by pulsed corona plasma was investigated. The results show that 212.6 mg/m3 of 2-CEES, with the gas flow rate of 2 m3/h, can be decontaminated to 0.09 mg/m3. According to the variation of the inlet and outlet concentration of 2-CEES vapor with retention time, it is found that the reaction of 2-CEES in a pulsed corona plasma system follows the first order reaction, with the reaction rate constant of 0.463 s-1. The decontamination mechanism is discussed based on an analysis of the dissociation energy of chemical bonds and decontamination products. The C-S bond adjacent to the Cl atom will be destroyed firstly to form CH3CH2S· and ·CH2CH2Cl radicals. CH3CH2S· can be decomposed to ·C2H5 and ·S. ·S can be oxidized to SO2, while ·C2H5 can be finally oxidized to CO2 and H2O. The C-Cl bond in the ·CH2CH2Cl radical can be destroyed to form ·CH2CH2. and ·Cl, which can be mineralized to CO2, H2O and HCl. The H atom in the ·CH2CH2Cl radical can also be substituted by ·Cl to form CHCl2-CHCl2.

  11. Contemporary Radical Prostatectomy

    PubMed Central

    Fu, Qiang; Moul, Judd W.; Sun, Leon

    2011-01-01

    Purpose. Patients diagnosed with clinically localized prostate cancer have more surgical treatment options than in the past. This paper focuses on the procedures' oncological or functional outcomes and perioperative morbidities of radical retropubic prostatectomy, radical perineal prostatectomy, and robotic-assisted laparoscopic radical prostatectomy. Materials and Methods. A MEDLINE/PubMed search of the literature on radical prostatectomy and other new management options was performed. Results. Compared to the open procedures, robotic-assisted radical prostatectomy has no confirmed significant difference in most literatures besides less blood loss and blood transfusion. Nerve sparing is a safe means of preserving potency on well-selected patients undergoing radical prostatectomy. Positive surgical margin rates of radical prostatectomy affect the recurrence and survival of prostate cancer. The urinary and sexual function outcomes have been vastly improved. Neoadjuvant treatment only affects the rate of positive surgical margin. Adjuvant therapy can delay and reduce the risk of recurrence and improve the survival of the high risk prostate cancer. Conclusions. For the majority of patients with organ-confined prostate cancer, radical prostatectomy remains a most effective approach. Radical perineal prostatectomy remains a viable approach for patients with morbid obesity, prior pelvic surgery, or prior pelvic radiation. Robot-assisted laparoscopic prostatectomy (RALP) has become popular among surgeons but has not yet become the firmly established standard of care. Long-term data have confirmed the efficacy of radical retropubic prostatectomy with disease control rates and cancer-specific survival rates. PMID:22110994

  12. [Degradation of thiometon in ethyl acetate].

    PubMed

    Satoh, M; Shimokawa, S; Kobata, M; Tanaka, T; Nakanishi, Y

    2001-04-01

    When performing multiresidue analysis of pesticides, the recovery of thiometon was less than 20% from carrots and eggplants, but about 100% from garlic chives and welsh onions. The recovery of thiometon was found to depend on the lot of ethyl acetate. A 2-year-old lot of ethyl acetate caused degradation of thiometon, but a fresh lot of ethyl acetate did not. Analysis showed that ethyl acetate stored for 2 years contained about 5 microL/mL of acetaldehyde. Thiometon was also degraded by acetone or acetonitrile, when acetaldehyde was added to them, in the same manner as by aged ethyl acetate. The fact that the recovery of thiometon from welsh onions was about 100% indicated that some of the mercaptans in allium vegetables may prevent thiometon degradation. Mercaptans such as L-cysteine and 3-mercaptoproionic acid were confirmed to prevent the degradation of thiometon and disulfoton. These findings show that mercaptans may be useful additives for analyzing thiometon and disulfoton. PMID:11486375

  13. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  14. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  15. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  16. The photodissociation dynamics of alkyl radicals

    NASA Astrophysics Data System (ADS)

    Giegerich, Jens; Fischer, Ingo

    2015-01-01

    The photodisscociation dynamics of the alkyl radicals i-propyl (CH(CH3)2) and t-butyl (C(CH3)3) are investigated by H-atom photofragment imaging. While i-propyl is excited at 250 nm, the photodynamics of t-butyl are explored over a large energy range using excitation wavelengths between 347 nm and 233 nm. The results are compared to those obtained previously for ethyl, CH3CH2, and to those reported for t-butyl using 248 nm excitation. The translational energy (ET) distribution of the H-atom photofragments is bimodal and appears rather similar for all three radicals. The low ET part of the distribution shows an isotropic photofragment angular distribution, while the high ET part is associated with a considerable anisotropy. Thus, for t-butyl, two H-atom loss channels of roughly equal importance have been identified in addition to the CH3-loss channel reported previously. A mechanism for the photodissociation of alkyl radicals is suggested that is based on interactions between Rydberg- and valence states.

  17. The photodissociation dynamics of alkyl radicals

    SciTech Connect

    Giegerich, Jens; Fischer, Ingo

    2015-01-28

    The photodisscociation dynamics of the alkyl radicals i-propyl (CH(CH{sub 3}){sub 2}) and t-butyl (C(CH{sub 3}){sub 3}) are investigated by H-atom photofragment imaging. While i-propyl is excited at 250 nm, the photodynamics of t-butyl are explored over a large energy range using excitation wavelengths between 347 nm and 233 nm. The results are compared to those obtained previously for ethyl, CH{sub 3}CH{sub 2}, and to those reported for t-butyl using 248 nm excitation. The translational energy (E{sub T}) distribution of the H-atom photofragments is bimodal and appears rather similar for all three radicals. The low E{sub T} part of the distribution shows an isotropic photofragment angular distribution, while the high E{sub T} part is associated with a considerable anisotropy. Thus, for t-butyl, two H-atom loss channels of roughly equal importance have been identified in addition to the CH{sub 3}-loss channel reported previously. A mechanism for the photodissociation of alkyl radicals is suggested that is based on interactions between Rydberg- and valence states.

  18. Reassessing Radical Pedagogy.

    ERIC Educational Resources Information Center

    Sweet, Stephen

    1998-01-01

    Responds to comments about, and critiques of, his own article on radical pedagogy. Outlines major points of contention raised by other commentators and responds to them, including matters of definition, power relations in the classroom, and tempering radical theory with pragmatism. (DSK)

  19. [Alchemists' humid radical].

    PubMed

    Lafont, Olivier

    2007-01-01

    The term radical has been used by chemists since the beginnings and even when they still were alchemists. The term "humid radical" is present in numerous alchemists' texts. It was used to represent a kind of "humid", which was considered as different from what is nowadays called "humid", but was a sort of principle necessary for life. PMID:17575839

  20. A highly effective gene delivery vector--hyperbranched poly(2-(dimethylamino)ethyl methacrylate) from in situ deactivation enhanced ATRP.

    PubMed

    Newland, Ben; Tai, Hongyun; Zheng, Yu; Velasco, Diego; Di Luca, Andrea; Howdle, Steven M; Alexander, Cameron; Wang, Wenxin; Pandit, Abhay

    2010-07-14

    A hyperbranched 2-(dimethylamino)ethyl methacrylate (DMAEMA) based polymer has been synthesised by a one-pot in situ deactivation enhanced atom transfer radical polymerisation (DE-ATRP); it exhibits much higher transfection ability than linear poly(DMAEMA) and is comparable to the well known branched poly(ethylene imine) (PEI) and the SuperFect dendrimer but with lower cytotoxicity. PMID:20514386

  1. Elastic electron scattering by ethyl vinyl ether

    SciTech Connect

    Khakoo, M. A.; Hong, L.; Kim, B.; Winstead, C.; McKoy, V.

    2010-02-15

    We report measured and calculated results for elastic scattering of low-energy electrons by ethyl vinyl ether (ethoxyethene), a prototype system for studying indirect dissociative attachment processes that may play a role in DNA damage. The integral cross section displays the expected {pi}{sup *} shape resonance. The agreement between the calculated and measured cross sections is generally good.

  2. Ethyl p-nitrophenyl phenylphosphorothioate (EPN)

    Integrated Risk Information System (IRIS)

    Ethyl p - nitrophenyl phenylphosphorothioate ( EPN ) ; CASRN 2104 - 64 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Ha

  3. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl formate. 184.1295 Section 184.1295 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  4. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl formate. 184.1295 Section 184.1295 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  5. 49 CFR 173.322 - Ethyl chloride.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Ethyl chloride. 173.322 Section 173.322 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation...

  6. Manufacturing Ethyl Acetate From Fermentation Ethanol

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  7. Striations in an ethyl alcohol glow discharge

    NASA Astrophysics Data System (ADS)

    Reyes, P. G.; Gómez, A.; Torres, C.; Martínez, H.; Castillo, F.; Vergara, J.

    2015-03-01

    This research shows the behavior of striations in glow discharge generated with high purity ethyl alcohol at a pressure of 0.6 Torr. This paper present the number of striations as a function of the of current and voltage discharge.

  8. Antifungal and antioxidant activity of Crassocephalum bauchiense (Hutch.) Milne-Redh ethyl acetate extract and fractions (Asteraceae)

    PubMed Central

    2014-01-01

    Background Crassocephalum bauchiense is a flowering plant, found in the West Region of Cameroon. Previous studied has highlighted the antibacterial and the dermal toxicological safety as well as the immunomodulatory activities of the ethyl acetate extract of its dry leaves. As an extension of the previous researches, the current work has been undertaken to evaluate the in vitro antifungal and antioxidant activities of C. bauchiense dried leaves ethyl acetate extract and fractions. Methods The extract was obtained by maceration in ethyl acetate and further fractionated into six fractions labeled F1 to F6 by flash chromatography. The antifungal activity of the extract and fractions against yeasts and dermatophytes was evaluated using broth microdilution method. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and β-carotene - linoleic acid assays. Results The extract (MIC = 0.125 - 4 mg/ml) was found to be more active on dermatophytes and yeasts compared to the fractions. The ethyl acetate extract and fractions exhibited strong scavenging activity on DPPH (CI50 = 28.57 - 389.38 μg/ml). The fractions F3 and F6 expressed best antioxidant activity on DPPH radicals compared to the crude extract. Conclusion The results of these findings clearly showed that C. bauchiense ethyl acetate extract has a significant antifungal and antioxidant activity. It is therefore a source of active compounds that might be used as antifungal and antioxidant agents. PMID:24742210

  9. Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride.

    PubMed

    Başkan, M Halim; Aydın, Murat

    2013-08-01

    The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3ĊHCOOC2H5, -CH2ĊHCOOH and -CH2ĊHCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed. PMID:23680512

  10. Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride

    NASA Astrophysics Data System (ADS)

    Başkan, M. Halim; Aydın, Murat

    2013-08-01

    The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3ĊHCOOC2H5, -CH2ĊHCOOH and -CH2ĊHCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed.

  11. Radical chemistry of artemisinin

    NASA Astrophysics Data System (ADS)

    Denisov, Evgenii T.; Solodova, S. L.; Denisova, Taisa G.

    2010-12-01

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  12. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  13. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare a scan from 10.5 microns...

  14. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  15. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  16. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  17. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... with regional registration are established for residues of the herbicide quizalofop ethyl,...

  18. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... with regional registration are established for residues of the herbicide quizalofop ethyl,...

  19. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... combined residues of the herbicide quizalofop (2- propanoic acid) and quizalofop ethyl (ethyl-2- propanoate...) Tolerances are established for the combined residues of the herbicide quizalofop (2- propanoic acid... herbicide quizalofop-p ethyl ester , and its acid metabolite quizalofop-p , and the S enantiomers of...

  20. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... with regional registration are established for residues of the herbicide quizalofop ethyl,...

  1. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  2. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  3. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  4. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  5. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  6. Hydroxyl radicals in indoor environments

    NASA Astrophysics Data System (ADS)

    Sarwar, Golam; Corsi, Richard; Kimura, Yosuke; Allen, David; Weschler, Charles J.

    Indoor hydroxyl radical concentrations were estimated using a new indoor air quality model which employs the SAPRC-99 atmospheric chemistry model to simulate indoor homogenous reactions. Model results indicate that typical indoor hydroxyl radical concentrations are lower than typical outdoor summertime urban hydroxyl radical levels of 5-10×10 6 molecules cm -3; however, indoor levels can be similar to or greater than typical nighttime outdoor hydroxyl radical levels of approximately 5×10 4 molecules cm -3. Effects of selected parameters on indoor hydroxyl radical concentrations are presented herein. Indoor hydroxyl radical concentrations are predicted to increase non-linearly with increasing outdoor ozone concentrations, indoor alkene emission rates, and air exchange rates. Indoor hydroxyl radical concentrations decrease with increasing outdoor nitric oxide concentrations. Indoor temperature and indoor light intensity have moderate impacts on indoor hydroxyl radical concentrations. Outdoor hydroxyl radical concentrations, outdoor nitrate (NO 3rad ) radical concentrations, outdoor hydroperoxy radical concentrations, and hydroxyl radical removal by indoor surfaces are predicted to have no appreciable impact on indoor hydroxyl radical concentrations. Production of hydroxyl radicals in indoor environments appears to be controlled primarily by reactions of alkenes with ozone, and nitric oxide with hydroperoxy radical. Estimated indoor hydroxyl radical levels may potentially affect indoor air quality. Two examples are presented in which reactions of d-limonene and α-pinene with indoor hydroxyl radicals produce aldehydes, which may be of greater concern than the original compounds.

  7. Electronic states of alkyl-radical-functionalized C20 fullerene using density functional theory

    NASA Astrophysics Data System (ADS)

    Abe, Shigeaki; Kawano, Shimpei; Toida, Yu; Nakamura, Mariko; Inoue, Satoshi; Sano, Hidehiko; Yoshida, Yasuhiro; Kawabata, Hiroshi; Tachikawa, Hiroto

    2016-03-01

    The structures and electronic states of alkyl-radical-functionalized C20 fullerenes (denoted by C20-R) have been investigated using density functional theory (DFT). The different alkyl radicals investigated were methyl, ethyl, propyl, and butyl radicals. The DFT calculation indicated that the alkyl radical binds to the carbon atom of C20 in the on-top site, thus forming a strong C-C single bond. The binding energies of the alkyl radicals to C20 were calculated to be 83.9-86.6 kcal/mol at the CAM-B3LYP/6-311G(d,p) level. The electronic states of the C20-R complex are discussed on the basis of the theoretical results.

  8. Production of ethyl alcohol from bananas

    SciTech Connect

    Jones, R.L.; Towns, T.

    1983-12-01

    The production of ethyl alcohol from waste bananas presents many special problems. During cooking, matting of the latex fibers from the banana peel recongeal when cooled and left untreated. This problem has been addressed by Alfaro by the use of CaC1/sub 2/. Separation of solids prior to distillation of the mashes in an economical fashion and use of the by product are also of concern to banana processors.

  9. Synthesis of Ethyl Salicylate Using Household Chemicals

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Hur, Chinhyu; Lee, Alan; Smith, Kurt

    1996-02-01

    Ethyl salicylate is synthesized, isolated, and characterized in a three-step process using simple equipment and household chemicals. First, acetylsalicylic acid is extracted from aspirin tablets with isopropyl alcohol, then hydrolyzed to salicylic acid with muriatic acid, and finally, the salicylic acid is esterified using ethanol and a boric acid catalyst. The experiment can be directed towards high school or university level students who have sufficient background in organic chemistry to recognize the structures and reactions that are involved.

  10. Computer assisted modeling of ethyl sulfate pharmacokinetics.

    PubMed

    Schmitt, Georg; Halter, Claudia C; Aderjan, Rolf; Auwaerter, Volker; Weinmann, Wolfgang

    2010-01-30

    For 12 volunteers of a drinking experiment the concentration-time-courses of ethyl sulfate (EtS) and ethanol were simulated and fitted to the experimental data. The concentration-time-courses were described with the same mathematical model as previously used for ethyl glucuronide (EtG). The kinetic model based on the following assumptions and simplifications: a velocity constant k(form) for the first order formation of ethyl sulfate from ethanol and an exponential elimination constant k(el). The mean values (and standard deviations) obtained for k(form) and k(el) were 0.00052 h(-1) (0.00014) and 0.561 h(-1) (0.131), respectively. Using the ranges of these parameters it is possible to calculate minimum and maximum serum concentrations of EtS based on stated ethanol doses and drinking times. The comparison of calculated and measured concentrations can prove the plausibility of alleged ethanol consumption and add evidence to the retrospective calculation of ethanol concentrations based on EtG concentrations. PMID:19913378

  11. The binding of ethyl isocyanide to ferroperoxidase

    PubMed Central

    Phelps, Charles; Antonini, Eraldo; Brunori, Maurizio

    1972-01-01

    The equilibrium and kinetics of ethyl isocyanide binding to ferroperoxidase were studied. At pH9.1 the results of both studies are consistent with a single-process model with an affinity constant of 95m−1 and combination and dissociation constants of 2.2×103m−1·s−1 and 23s−1 respectively. Ethyl isocyanide is not bound significantly at pH values lower than 6.0, and in this behaviour and the pH-dependence of the affinity constant, similarities exist between isocyanide and cyanide binding. The enthalpy of the process measured by equilibrium methods is −59kJ/mol (−14kcal/mol). At pH values below 9, the ethyl isocyanide adduct changes in a slow time-dependent manner, giving rise to a new species. These changes are reversible on increasing the pH. The results are discussed in relation to other known information about ligand binding to ferroperoxidase and to myoglobin. PMID:5084796

  12. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  13. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  14. Free Radical Reactions in Food.

    ERIC Educational Resources Information Center

    Taub, Irwin A.

    1984-01-01

    Discusses reactions of free radicals that determine the chemistry of many fresh, processed, and stored foods. Focuses on reactions involving ascorbic acid, myoglobin, and palmitate radicals as representative radicals derived from a vitamin, metallo-protein, and saturated lipid. Basic concepts related to free radical structure, formation, and…

  15. Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.

    PubMed

    Cataldo, Franco

    2013-01-01

    Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C≈1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C≈1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (≈243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value. PMID:23969233

  16. Chemistry of carotenoid neutral radicals.

    PubMed

    Ligia Focsan, A; Magyar, Adam; Kispert, Lowell D

    2015-04-15

    Proton loss from the carotenoid radical cations (Car(+)) to form neutral radicals (#Car) was investigated by numerous electrochemical, EPR, ENDOR and DFT studies described herein. The radical cation and neutral radicals were formed in solution electrochemically and stabilized on solid silica-alumina and MCM-41 matrices. Carotenoid neutral radicals were recently identified in Arabidopsis thaliana plant and photosystem II samples. Deprotonation at the terminal ends of a zeaxanthin radical cation could provide a secondary photoprotection pathway which involves quenching excited state chlorophyll by the long-lived zeaxanthin neutral radicals formed. PMID:25687648

  17. Comparison of Diffusion Coefficients of Aryl Carbonyls and Aryl Alcohols in Hydroxylic Solvents. Evidence that the Diffusion of Ketyl Radicals in Hydrogen-Bonding Solvents is Not Anomalous?

    SciTech Connect

    Autrey, S Thomas ); Camaioni, Donald M. ); Kandanarachchi, Pramod H.; Franz, James A. )

    2000-12-01

    The diffusion coefficients of a benzyl-, sec-phenethyl-, and diphenylmethyl alcohol and the corresponding aryl carbonyls (benzaldehyde, acetophenone and benzophenone) were measured by Taylor's dispersion method in both ethyl and isopropyl alcohol. The experimental values are compared to published transient grating measurements of the corresponding aryl ketyl radicals (benzyl-, sec-phenethyl-, and diphenylmethyl-ketyl radical). In general, the diffusion coefficient of the aryl alcohols and the corresponding aryl ketyl radicals are equivalent within experimental error. This work shows that the diffusion of ketyl radicals is not anomalously slow and that aryl alcohols are significantly better models than the corresponding aryl ketones for analyzing the diffusion of aryl ketyl radicals in both ethyl and isopropyl alcohol. Empirical estimates of the diffusion coefficients of aryl alcohols using the Spernol-Wirtz and Wilke-Chang modifications to the Stokes-Einstein diffusion equation do not adequately account for the interactions between the aryl ketyl radicals or aryl alcohols with the hydroxylic solvents ethyl and isopropyl alcohol. The excellent agreement between the experimental diffusion coefficients of the aryl alcohols and the corresponding ketyl radicals show that the transient grating method can provide accurate estimates for the diffusion coefficients of transient species. This is especially important when a stable model is not available, for example the pyranyl radical.

  18. The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings.

    PubMed

    Buckingham, Grant T; Ormond, Thomas K; Porterfield, Jessica P; Hemberger, Patrick; Kostko, Oleg; Ahmed, Musahid; Robichaud, David J; Nimlos, Mark R; Daily, John W; Ellison, G Barney

    2015-01-28

    The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C6H5CH2, as well as a set of isotopically labeled radicals: C6H5CD2, C6D5CH2, and C6H5 (13)CH2. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C5H4=C=CH2, H atom, C5H4-C ≡ CH, C5H5, HCCCH2, and HC ≡ CH. Pyrolysis of the C6H5CD2, C6D5CH2, and C6H5 (13)CH2 benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C6H5CH2⇋C7H7. These labeling studies suggest that there must be other thermal decomposition routes for the C6H5CH2 radical that differ from the fulvenallene pathway. PMID:25637987

  19. Intense, hyperthermal source of organic radicals for matrix-isolation spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Xu; Friderichsen, Anders V.; Nandi, Sreela; Ellison, G. Barney; David, Donald E.; McKinnon, J. Thomas; Lindeman, Theodore G.; Dayton, David C.; Nimlos, Mark R.

    2003-06-01

    We have incorporated a pulsed, hyperthermal nozzle with a cryostat to study the matrix-isolated infrared spectroscopy of organic radicals. The radicals are produced by pyrolysis in a heated, narrow-bore (1-mm-diam) SiC tube and then expanded into the cryostat vacuum chamber. The combination of high nozzle temperature (up to 1800 K) and near-sonic flow velocities (on the order of 104cm s-1) through the length of the 2 cm tube allows for high yield of radicals (approximately 1013 radicals pulse-1) and low residence time (on the order of 10 μs) in the nozzle. We have used this hyperthermal nozzle/matrix isolation experiment to observe the IR spectra of complex radicals such as allyl radical (CH2CHCH2), phenyl radical (C6H5), and methylperoxyl radical (CH3OO). IR spectra of samples produced with a hyperthermal nozzle are remarkably clean and relatively free of interfering radical chemistry. By monitoring the unimolecular thermal decomposition of allyl ethyl ether in the nozzle using matrix IR spectroscopy, we have derived the residence time (τnozzle) of the gas pulse in the nozzle to be around 30 μs.

  20. The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings

    NASA Astrophysics Data System (ADS)

    Buckingham, Grant T.; Ormond, Thomas K.; Porterfield, Jessica P.; Hemberger, Patrick; Kostko, Oleg; Ahmed, Musahid; Robichaud, David J.; Nimlos, Mark R.; Daily, John W.; Ellison, G. Barney

    2015-01-01

    The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C6H5CH2, as well as a set of isotopically labeled radicals: C6H5CD2, C6D5CH2, and C6H513CH2. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C5H4=C=CH2, H atom, C5H4—C ≡ CH, C5H5, HCCCH2, and HC ≡ CH. Pyrolysis of the C6H5CD2, C6D5CH2, and C6H513CH2 benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C6H5CH2⇋C7H7. These labeling studies suggest that there must be other thermal decomposition routes for the C6H5CH2 radical that differ from the fulvenallene pathway.

  1. In vitro protection of biological macromolecules against oxidative stress and in vivo toxicity evaluation of Acacia nilotica (L.) and ethyl gallate in rats

    PubMed Central

    2014-01-01

    Background Recently, enormous research has been focused on natural bioactive compounds possessing potential antioxidant and anticancer properties using cell lines and animal models. Acacia nilotica (L.) is widely distributed in Asia, Africa, Australia and Kenya. The plant is traditionally used to treat mouth, ear and bone cancer. However, reports on Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan regarding its toxicity profile is limited. Hence in this study, we investigated the antioxidant capacity and acute toxicity of ethyl gallate, a phenolic antioxidant present in the A. nilotica (L.) leaf extract. Methods The antioxidant activity of ethyl gallate against Fenton’s system (Fe3+/H2O2/ascorbic acid) generated oxidative damage to pBR322 DNA and BSA was investigated. We also studied the interaction of ethyl gallate to CT-DNA by wave scan and FTIR analysis. The amount of ethyl gallate present in the A. nilotica (L.) leaf extract was calculated using HPLC and represented in gram equivalence of ethyl gallate. The acute toxicity profile of ethyl gallate in the A. nilotica (L.) leaf extract was analyzed in albino Wistar rats. Measurement of liver and kidney function markers, total proteins and glucose were determined in the serum. Statistical analysis was done using statistical package for social sciences (SPSS) tool version 16.0. Results Ethyl gallate was found to be effective at 100 μg/mL concentration by inhibiting the free radical mediated damage to BSA and pBR322 DNA. We also found that the interaction of ethyl gallate and A. nilotica (L.) leaf extract to CT-DNA occurs through intercalation. One gram of A. nilotica (L.) leaf extract was found to be equivalent to 20 mg of ethyl gallate through HPLC analysis. Based on the acute toxicity results, A. nilotica (L.) leaf extract and ethyl gallate as well was found to be non-toxic and safe. Conclusions Results revealed no mortality or abnormal biochemical changes in vivo and the protective effect

  2. Optimization of ethyl ester production assisted by ultrasonic irradiation.

    PubMed

    Noipin, K; Kumar, S

    2015-01-01

    This study presents the optimization of the continuous flow potassium hydroxide-catalyzed synthesis of ethyl ester from palm oil with ultrasonic assistance. The process was optimized by application of factorial design and response surface methodology. The independent variables considered were ethanol to oil molar ratio, catalyst concentration, reaction temperature and ultrasonic amplitude; and the response was ethyl ester yield. The results show that ethanol to oil molar ratio, catalyst concentration, and ultrasonic amplitude have positive effect on ethyl ester yield, whereas reaction temperature has negative influence on ethyl ester yield. Second-order models were developed to predict the responses analyzed as a function of these three variables, and the developed models predicts the results in the experimental ranges studied adequately. This study shows that ultrasonic irradiation improved the ethyl ester production process to achieve ethyl ester yields above 92%. PMID:25116594

  3. [Aging and free radicals].

    PubMed

    Manso, C

    1992-02-01

    Several theories on aging are presented. All of them give important contributions but none explains all the aspects of the problem. Oxygen radicals produced during cellular combustion contribute to aging through multiple cumulative microlesions throughout life. The importance of glucose is emphasized; it forms early and late Maillard compounds. Other causes of aging are discussed. PMID:1595373

  4. Radical School Reform.

    ERIC Educational Resources Information Center

    Gross, Beatrice, Ed.; Gross, Ronald, Ed.

    This book provides a comprehensive examination of the nature of the school crisis and the ways in which radical thinkers and educators are dealing with it. Excerpts from the writings of Jonathan Kozol, John Holt, Kenneth Clark, and others are concerned with the realities of education in ghettos and suburbs. Paul Goodman, Marshall McLuhan, Sylvia…

  5. Tyrosyl Radicals in Dehaloperoxidase

    PubMed Central

    Dumarieh, Rania; D'Antonio, Jennifer; Deliz-Liang, Alexandria; Smirnova, Tatyana; Svistunenko, Dimitri A.; Ghiladi, Reza A.

    2013-01-01

    Dehaloperoxidase (DHP) from Amphitrite ornata, having been shown to catalyze the hydrogen peroxide-dependent oxidation of trihalophenols to dihaloquinones, is the first oxygen binding globin that possesses a biologically relevant peroxidase activity. The catalytically competent species in DHP appears to be Compound ES, a reactive intermediate that contains both a ferryl heme and a tyrosyl radical. By simulating the EPR spectra of DHP activated by H2O2, Thompson et al. (Thompson, M. K., Franzen, S., Ghiladi, R. A., Reeder, B. J., and Svistunenko, D. A. (2010) J. Am. Chem. Soc. 132, 17501–17510) proposed that two different radicals, depending on the pH, are formed, one located on either Tyr-34 or Tyr-28 and the other on Tyr-38. To provide additional support for these simulation-based assignments and to deduce the role(s) that tyrosyl radicals play in DHP, stopped-flow UV-visible and rapid-freeze-quench EPR spectroscopic methods were employed to study radical formation in DHP when three tyrosine residues, Tyr-28, Tyr-34, and Tyr-38, were replaced either individually or in combination with phenylalanines. The results indicate that radicals form on all three tyrosines in DHP. Evidence for the formation of DHP Compound I in several tyrosine mutants was obtained. Variants that formed Compound I showed an increase in the catalytic rate for substrate oxidation but also an increase in heme bleaching, suggesting that the tyrosines are necessary for protecting the enzyme from oxidizing itself. This protective role of tyrosines is likely an evolutionary adaptation allowing DHP to avoid self-inflicted damage in the oxidative environment. PMID:24100039

  6. Testing for ethanol markers in hair: discrepancies after simultaneous quantification of ethyl glucuronide and fatty acid ethyl esters.

    PubMed

    Kintz, P; Nicholson, D

    2014-10-01

    The hair of 97 cases were analysed for ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE, including ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) according to the Society of Hair Testing guidelines to examine the role of both tests in documenting chronic excessive alcohol drinking, particularly when the results are in contradiction. 27 (27.8%) results were EtG negative and FAEE positive, when applying the SoHT cut-offs, probably due to the use of alcohol-containing hair products. Four cases (4.1%) were EtG positive and FAEE negative that were attributed to the use of herbal lotions containing EtG. PMID:24794020

  7. Toward Radicalizing Community Service Learning

    ERIC Educational Resources Information Center

    Sheffield, Eric C.

    2015-01-01

    This article advocates a radicalized theoretical construction of community service learning. To accomplish this radicalization, I initially take up a discussion of traditional understandings of CSL rooted in pragmatic/progressive thought. I then suggest that this traditional structural foundation can be radicalized by incorporating Deborah…

  8. Free radical explosive composition

    DOEpatents

    Walker, Franklin E.; Wasley, Richard J.

    1979-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a getter additive comprising a compound or mixture of compounds capable of capturing or deactivating free radicals or ions under mechanical or electrical shock conditions and which is not an explosive. Exemplary getter additives are isocyanates, olefins and iodine.

  9. Free radical propulsion concept

    NASA Technical Reports Server (NTRS)

    Hawkins, C. E.; Nakanishi, S.

    1981-01-01

    The concept of a free radical propulsion system, utilizing the recombination energy of dissociated low molecular weight gases to produce thrust, is analyzed. The system, operating at a theoretical impulse with hydrogen, as high as 2200 seconds at high thrust to power ratio, is hypothesized to bridge the gap between chemical and electrostatic propulsion capabilities. A comparative methodology is outlined by which characteristics of chemical and electric propulsion for orbit raising mission can be investigated. It is noted that free radicals proposed in rockets previously met with difficulty and complexity in terms of storage requirements; the present study proposes to eliminate the storage requirements by using electric energy to achieve a continuous-flow product of free radicals which are recombined to produce a high velocity propellant. Microwave energy used to dissociate a continuously flowing gas is transferred to the propellant via three-body-recombination for conversion to propellant kinetic energy. Microwave plasma discharge was found in excess of 90 percent over a broad range of pressure in preliminary experiments, and microwave heating compared to electrothermal heating showed much higher temperatures in gasdynamic equations.

  10. Laparoscopic radical cystectomy

    PubMed Central

    Fergany, Amr

    2012-01-01

    Objective Laparoscopic radical cystectomy (LRC) has emerged as a minimally invasive alternative to open radical cystectomy (ORC). This review focuses on patient selection criteria, technical aspects and postoperative outcomes of LRC. Methods Material for the review was obtained by a PubMed search over the last 10 years, using the keywords ‘laparoscopic radical cystectomy’ and ‘laparoscopic bladder cancer’ in human subjects. Results Twenty-two publications selected for relevance and content were used for this review from the total search yield. The level of evidence was IIb and III. LRC results in comparable short- and intermediate-range oncological outcomes to ORC, with generally longer operative times but decreased blood loss, postoperative pain and hospital stay. Overall operative and postoperative morbidity are equivalent. Conclusion In experienced hands, LRC is an acceptable minimally invasive alternative to ORC in selected patients, with the main advantage of decreased blood loss and postoperative pain, as well as a shorter hospital stay and recovery. PMID:26558003

  11. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    SciTech Connect

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  12. IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE (2003 Final)

    EPA Science Inventory

    EPA is announcing the release of the final report, "Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS)". The updated Summary for Methyl Ethyl Ketone and accompanying Quickview have also been added to the IRIS Database.

  13. 46 CFR 151.50-42 - Ethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ethyl ether. 151.50-42 Section 151.50-42 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-42 Ethyl ether. (a)(1) Gravity...

  14. Occupational allergic contact dermatitis from ethyl cyanoacrylate.

    PubMed

    Bruze, M; Björkner, B; Lepoittevin, J P

    1995-03-01

    Glues based on cyanoacrylates are widely used as contact adhesives for metal, glass, rubber, plastics and textiles, as well for biological materials, including binding tissues and sealing wounds in surgery. In this paper, an apprentice cobbler with an occupational allergic contact dermatitis from an ethyl cyanoacrylate glue, in which the major monomer was shown to be the sensitizer, is reported. Initial patch testing with the cyanoacrylate glue dissolved in acetone with the Finn Chamber (aluminium) technique yielded false-negative reactions. Positive test reactions were obtained with the same preparations using Van der Bend chambers. With petrolatum as vehicle for the glue, there was no difference between Finn Chamber technique and Van der Bend chamber technique. The role of aluminium in the false-negative reactions is discussed. PMID:7774187

  15. A morphogenetic regulatory role for ethyl alcohol in Candida albicans.

    PubMed

    Chauhan, Nitin M; Raut, Jayant S; Karuppayil, S Mohan

    2011-11-01

    Regulation of morphogenesis through the production of chemical signalling molecules such as isoamyl alcohol, 2-phenylethyl alcohol, 1-dodecanol, E-nerolidol and farnesol is reported in Candida albicans. The present study focuses on the effect of ethyl alcohol on C. albicans dimorphism and biofilm development. Ethyl alcohol inhibited germ tube formation induced by the four standard inducers in a concentration-dependent manner. The germ tube inhibitory concentration (4%) did not have any effect on the growth and viability of C. albicans cells. Ethyl alcohol also inhibited the elongation of germ tubes. Four percentage of ethyl alcohol significantly inhibited biofilm development on polystyrene and silicone surfaces. We suggest a potential morphogenetic regulatory role for ethyl alcohol, which may influence dissemination, virulence and establishment of infection. PMID:21605190

  16. Fragmentation dynamics of the ethyl bromide and ethyl iodide cations: a velocity-map imaging study.

    PubMed

    Gardiner, Sara H; Karsili, Tolga N V; Lipciuc, M Laura; Wilman, Edward; Ashfold, Michael N R; Vallance, Claire

    2014-02-01

    The photodissociation dynamics of ethyl bromide and ethyl iodide cations (C2H5Br(+) and C2H5I(+)) have been studied. Ethyl halide cations were formed through vacuum ultraviolet (VUV) photoionization of the respective neutral parent molecules at 118.2 nm, and were photolysed at a number of ultraviolet (UV) photolysis wavelengths, including 355 nm and wavelengths in the range from 236 to 266 nm. Time-of-flight mass spectra and velocity-map images have been acquired for all fragment ions and for ground (Br) and spin-orbit excited (Br*) bromine atom products, allowing multiple fragmentation pathways to be investigated. The experimental studies are complemented by spin-orbit resolved ab initio calculations of cuts through the potential energy surfaces (along the RC-Br/I stretch coordinate) for the ground and first few excited states of the respective cations. Analysis of the velocity-map images indicates that photoexcited C2H5Br(+) cations undergo prompt C-Br bond fission to form predominantly C2H5(+) + Br* products with a near-limiting 'parallel' recoil velocity distribution. The observed C2H3(+) + H2 + Br product channel is thought to arise via unimolecular decay of highly internally excited C2H5(+) products formed following radiationless transfer from the initial excited state populated by photon absorption. Broadly similar behaviour is observed in the case of C2H5I(+), along with an additional energetically accessible C-I bond fission channel to form C2H5 + I(+) products. HX (X = Br, I) elimination from the highly internally excited C2H5X(+) cation is deemed the most probable route to forming the C2H4(+) fragment ions observed from both cations. Finally, both ethyl halide cations also show evidence of a minor C-C bond fission process to form CH2X(+) + CH3 products. PMID:24317740

  17. Mechanistic insight into alkylation of the ethyl acetoacetate anion with different ethyl halides

    NASA Astrophysics Data System (ADS)

    Marković, S.; Đurđević, J.; Vukosavljević, M.; Petrović, Z.

    2013-12-01

    The alkylation reactions of the ambident ethyl acetoacetate anion with C2H5X (X = F, Cl, Br, and I) in the O2, C3, and O4 positions of the anion were investigated at the B3LYP/6-311+G( d,p) level of theory. It was found that the ethylation reaction does not occur in the position O4, as well as with ethyl fluoride in any position of the anion, due to very high activation energies and thermodynamic instability of the hypothetic products. The activation energies for the reactions in the position O2 are lower in comparison to the position C3, but the products of the reactions in the C3 position are more stable than those in the position O4, implying that the C/O products ratio is controlled by both thermodynamic and kinetic factors, leading to the O2-product with the chloride, and C3-product with the iodide as leaving group.

  18. Dispersion of luminescent nanoparticles in different derivatives of poly(ethyl methacrylate).

    PubMed

    Davion, B; Delhorbe, V; Péralta, S P; Goubard, F; Vidal, F

    2011-04-01

    Gd2O3:Tb(5%) nanoparticles were prepared via the polyol route and dispersed without any stabilizer in several ethyl methacrylate derivatives matrices such as poly(ethyl methacrylate), poly(2-methoxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate) (PHEMA). Nanocomposites were obtained via free-radical polymerization of methacrylic monomers with ethylene glycol dimethacrylate as crosslinker and colloidal solution of Gd2O3:Tb(5%) nanoparticles. Best results are obtained with PHEMA in which the dispersed Gd2O3:Tb(5%) nanoparticles are spherical with a mean diameter of 15 nm, as measured by TEM. The obtained solid Gd2O3:Tb(5%)/PHEMA nanocomposites are highly transparent (in the visible spectral range) and exhibit characteristic photoluminescence of Tb3+ 5D4-7F(J) (J = 6-3), with 5D4-7F5 strong green emission at 536 nm upon UV excitation. The nanoparticles and nanocomposites have been well characterized by high-resolution transmission electron microscope (TEM), UV/Vis transmission spectra, photoluminescence excitation, and emission spectra. PMID:21776688

  19. Stimuli-responsive spherical brushes based on D-galactopyranose and 2-(dimethylamino)ethyl methacrylate.

    PubMed

    Arslan, Hülya; Pfaff, André; Lu, Yan; Stepanek, Petr; Müller, Axel H E

    2014-01-01

    Stimuli-responsive spherical brushes composed of 6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose (MAIGal) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) are prepared via atom transfer radical polymerization (ATRP) using cross-linked polystyrene nanoparticles covered with a thin layer of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) as ATRP initiator by the "grafting from" approach. The stimuli-responsive behavior of the deprotected spherical PMAGal-b-PDMAEMA block copolymer brushes is investigated by dynamic light scattering and cryogenic transmission electron microscopy. A brush with arms containing 160 MAGal and 170 DMAEMA monomer units shows a significant contraction of the hydrodynamic radius from 20 to 70 °C at pH = 8 with a cloud point at ≈40 °C, whereas no LCST is detected at pH = 6 and 7 due to the protonation of the DMAEMA units. Aggregates occur at low temperatures and pH 8 due to intermolecular interactions between the chains of different brushes, which disappear above LCST, when the PDMAEMA chains fold back to the core of the brushes, exposing the glycopolymer chains to the outside. PMID:24106068

  20. Perspectives for the biotechnological production of ethyl acetate by yeasts.

    PubMed

    Löser, Christian; Urit, Thanet; Bley, Thomas

    2014-06-01

    Ethyl acetate is an environmentally friendly solvent with many industrial applications. The production of ethyl acetate currently proceeds by energy-intensive petrochemical processes which are based on natural gas and crude oil without exception. Microbial synthesis of ethyl acetate could become an interesting alternative. The formation of esters as aroma compounds in food has been repeatedly reviewed, but a survey which deals with microbial synthesis of ethyl acetate as a bulk product is missing. The ability of yeasts for producing larger amounts of this ester is known for a long time. In the past, this potential was mainly of scientific interest, but in the future, it could be applied to large-scale ester production from renewable raw materials. Pichia anomala, Candida utilis, and Kluyveromyces marxianus are yeasts which convert sugar into ethyl acetate with a high yield where the latter is the most promising one. Special attention was paid to the mechanism of ester synthesis including regulatory aspects and to the maximum and expectable yield. Synthesis of much ethyl acetate requires oxygen which is usually supplied by aeration. Ethyl acetate is highly volatile so that aeration results in its phase transfer and stripping. This stripping process cannot be avoided but requires adequate handling during experimentation and offers a chance for a cost-efficient process-integrated recovery of the synthesized ester. PMID:24788328

  1. Oligorotaxane Radicals under Orders.

    PubMed

    Wang, Yuping; Frasconi, Marco; Liu, Wei-Guang; Sun, Junling; Wu, Yilei; Nassar, Majed S; Botros, Youssry Y; Goddard, William A; Wasielewski, Michael R; Stoddart, J Fraser

    2016-02-24

    A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components-namely oligoviologens-in which different numbers of 4,4'-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT(4+)) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY(•+) radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne-azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers. PMID:27163033

  2. Oligorotaxane Radicals under Orders

    PubMed Central

    2016-01-01

    A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY2+) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT4+) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY•+ radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne–azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers. PMID:27163033

  3. Radically innovative steelmaking technologies

    NASA Astrophysics Data System (ADS)

    Szekely, Julian

    1980-09-01

    The steel industry is faced with serious problems caused by the increasing cost of energy, labor and capital and by tough overseas competition, employing new highly efficient process plants. The very high cost of capital and of capital equipment renders the construction of new green field site plants, exemplifying the best available technology economically unattractive. For this reason, over the long term the development radically innovative steelmaking technologies appears to be the only satisfactory resolution of this dilemma. The purpose of this article is to present a critical review of some of the radically innovative steelmaking technologies that have been proposed during the past few years and to develop the argument that these indeed do deserve serious consideration at the present time. It should be stressed, however, that these innovative technologies can be implemented only as part of a carefully conceived long range plan, which contains as a subset short term solutions, such as trigger prices improved investment credits, and so forth and intermediate term solutions, such as more extensive use of continuous casting, external desulfurization and selective modernization in general.

  4. Ethyl pyruvate protects colonic anastomosis from ischemia-reperfusion injury.

    PubMed

    Unal, B; Karabeyoglu, M; Huner, T; Canbay, E; Eroglu, A; Yildirim, O; Dolapci, M; Bilgihan, A; Cengiz, O

    2009-03-01

    Ethyl pyruvate is a simple derivative in Ca(+2)- and K(+)-containing balanced salt solution of pyruvate to avoid the problems associated with the instability of pyruvate in solution. It has been shown to ameliorate the effects of ischemia-reperfusion (I/R) injury in many organs. It has also been shown that I/R injury delays the healing of colonic anastomosis. In this study, the effect of ethyl pyruvate on the healing of colon anastomosis and anastomotic strength after I/R injury was investigated. Anastomosis of the colon was performed in 32 adult male Wistar albino rats divided into 4 groups of 8 individuals: (1) sham-operated control group (group 1); (2) 30 minutes of intestinal I/R by superior mesenteric artery occlusion (group 2); (3) I/R+ ethyl pyruvate (group 3), ethyl pyruvate was administered as a 50-mg/kg/d single dose; and (4) I/R+ ethyl pyruvate (group 4), ethyl pyruvate administration was repeatedly (every 6 hours) at the same dose (50 mg/kg). On the fifth postoperative day, animals were killed. Perianastomotic tissue hydroxyproline contents and anastomotic bursting pressures were measured in all groups. When the anastomotic bursting pressures and tissue hydroxyproline contents were compared, it was found that they were decreased in group 2 when compared with groups 1, 3, and 4 (P < .05). Both anastomotic bursting pressure (P = .005) and hydroxyproline content (P < .001) levels were found to be significantly increased with ethyl pyruvate administration when compared with group 2. When ethyl pyruvate administration doses were compared, a significant difference was not observed (P > .05). Ethyl pyruvate significantly prevents the delaying effect of I/R injury on anastomotic strength and healing independent from doses of administration. PMID:19064591

  5. Radical-radical interactions among oxidized guanine bases including guanine radical cation and dehydrogenated guanine radicals.

    PubMed

    Zhao, Jing; Wang, Mei; Yang, Hongfang; Zhang, Meng; Liu, Ping; Bu, Yuxiang

    2013-09-19

    We present here a theoretical investigation of the structural and electronic properties of di-ionized GG base pairs (G(•+)G(•+),G(-H1)(•)G(•+), and G(-H1)(•)G(-H1)(•)) consisting of the guanine cation radical (G(•+)) and/or dehydrogenated guanine radical (G(-H1)(•)) using density functional theory calculations. Different coupling modes (Watson-Crick/WC, Hoogsteen/Hoog, and minor groove/min hydrogen bonding, and π-π stacking modes) are considered. We infer that a series of G(•+)G(•+) complexes can be formed by the high-energy radiation. On the basis of density functional theory and complete active space self-consistent (CASSCF) calculations, we reveal that in the H-bonded and N-N cross-linked modes, (G(•+)G(•+))WC, (G(-H1)(•)G(-H1)(•))WC, (G(-H1)(•)G(-H1)(•))minI, and (G(-H1)(•)G(-H1)(•))minIII have the triplet ground states; (G(•+)G(•+))HoogI, (G(-H1)(•)G(•+))WC, (G(-H1)(•)G(•+))HoogI, (G(-H1)(•)G(•+))minI, (G(-H1)(•)G(•+))minII, and (G(-H1)(•)G(-H1)(•))minII possess open-shell broken-symmetry diradical-characterized singlet ground states; and (G(•+)G(•+))HoogII, (G(•+)G(•+))minI, (G(•+)G(•+))minII, (G(•+)G(•+))minIII, (G(•+)G(•+))HoHo, (G(-H1)(•)G(•+))minIII, (G(-H1)(•)G(•+))HoHo, and (G(-H1)(•)G(-H1)(•))HoHo are the closed-shell systems. For these H-bonded diradical complexes, the magnetic interactions are weak, especially in the diradical G(•+)G(•+) series and G(-H1)(•)G(-H1)(•) series. The magnetic coupling interactions of the diradical systems are controlled by intermolecular interactions (H-bond, electrostatic repulsion, and radical coupling). The radical-radical interaction in the π-π stacked di-ionized GG base pairs ((G(•+)G(•+))ππ, (G(-H1)(•)G(•+))ππ, and (G(-H1)(•)G(-H1)(•))ππ) are also considered, and the magnetic coupling interactions in these π-π stacked base pairs are large. This is the first theoretical prediction that some di

  6. On the cause of low thermal stability of ethyl halodiazoacetates

    PubMed Central

    Mortén, Magnus; Hennum, Martin

    2016-01-01

    Summary Rates for the thermal decomposition of ethyl halodiazoacetates (halo = Cl, Br, I) have been obtained, and reported herein are their half-lives. The experimental results are supported by DFT calculations, and we provide a possible explanation for the reduced thermal stability of ethyl halodiazoacetates compared to ethyl diazoacetate and for the relative decomposition rates between the chloro, bromo and iodo analogs. We have also briefly studied the thermal, non-catalytic cyclopropanation of styrenes and compared the results to the analogous Rh(II)-catalyzed reactions. PMID:27559411

  7. On the cause of low thermal stability of ethyl halodiazoacetates.

    PubMed

    Mortén, Magnus; Hennum, Martin; Bonge-Hansen, Tore

    2016-01-01

    Rates for the thermal decomposition of ethyl halodiazoacetates (halo = Cl, Br, I) have been obtained, and reported herein are their half-lives. The experimental results are supported by DFT calculations, and we provide a possible explanation for the reduced thermal stability of ethyl halodiazoacetates compared to ethyl diazoacetate and for the relative decomposition rates between the chloro, bromo and iodo analogs. We have also briefly studied the thermal, non-catalytic cyclopropanation of styrenes and compared the results to the analogous Rh(II)-catalyzed reactions. PMID:27559411

  8. Oxygen radicals and renal diseases.

    PubMed

    Klahr, S

    1997-01-01

    Reactive oxygen metabolites (superoxide, hydrogen peroxide, hydroxyl radical, and hypochlorous acid) are important mediators of renal damage in acute renal failure and glomerular and tubulointerstitial diseases. The role of these oxygen metabolites in the above entities is discussed, and the effects of antioxidants and scavengers of O2 radicals are considered. The role of oxygen radicals in the regulation of gene transcription is also considered. PMID:9387104

  9. Radical intermediates in the addition of OH to propene: photolytic precursors and angular momentum effects.

    PubMed

    Brynteson, M D; Womack, C C; Booth, R S; Lee, S-H; Lin, J J; Butler, L J

    2014-05-01

    We investigate the photolytic production of two radical intermediates in the reaction of OH with propene, one from addition of the hydroxyl radical to the terminal carbon and the other from addition to the center carbon. In a collision-free environment, we photodissociate a mixture of 1-bromo-2-propanol and 2-bromo-1-propanol at 193 nm to produce these radical intermediates. The data show two primary photolytic processes occur: C-Br photofission and HBr photoelimination. Using a velocity map imaging apparatus, we measured the speed distribution of the recoiling bromine atoms, yielding the distribution of kinetic energies of the nascent C3H6OH radicals + Br. Resolving the velocity distributions of Br((2)P(1/2)) and Br((2)P(3/2)) separately with 2 + 1 REMPI allows us to determine the total (vibrational + rotational) internal energy distribution in the nascent radicals. Using an impulsive model to estimate the rotational energy imparted to the nascent C3H6OH radicals, we predict the percentage of radicals having vibrational energy above and below the lowest dissociation barrier, that to OH + propene; it accurately predicts the measured velocity distribution of the stable C3H6OH radicals. In addition, we use photofragment translational spectroscopy to detect several dissociation products of the unstable C3H6OH radicals: OH + propene, methyl + acetaldehyde, and ethyl + formaldehyde. We also use the angular momenta of the unstable radicals and the tensor of inertia of each to predict the recoil kinetic energy and angular distributions when they dissociate to OH + propene; the prediction gives an excellent fit to the data. PMID:24758210

  10. Amphiphilic graft copolymers with ethyl cellulose backbone: Synthesis, self-assembly and tunable temperature-CO2 response.

    PubMed

    Yuan, Weizhong; Zou, Hui; Shen, Jin

    2016-01-20

    Amphiphilic ethyl cellulose-graft-poly(N,N-dimethylaminoethyl methacrylate) (EC-g-PDMAEMA) and ethyl cellulose-graft-poly(2-(2-methoxyethoxy)ethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate) (EC-g-P(MEO2MA-co-DMAEMA)) graft copolymers were easily synthesized by atom transfer radical polymerization (ATRP). The micelles self-assembled from the copolymer presented switchable temperature-CO2 dually responsive properties. The value of lower critical solution temperature (LCST) for the copolymer micelle solutions could be adjusted by CO2/Ar. Moreover, due to the alteration of the ratio of DMAEMA to MEO2MA, the LCST values of the micelle solutions decreased with the increase of MEO2MA in copolymer. The temperature-CO2 dually responsive properties of the copolymer were reversible and could be accomplished through altering the temperature and bubbling CO2/Ar. The hydrodynamic radius (Rh) of the copolymer micelles was also influenced by the ratio of DMAEMA to MEO2MA and the stimuli of temperature and CO2/Ar. As a drug release system, the copolymer micelles could achieve the control release of doxorubicin (DOX) by changing the temperature and alternatively bubbling CO2/Ar. PMID:26572349

  11. Free radical propulsion concept

    NASA Technical Reports Server (NTRS)

    Hawkins, C. E.; Nakanishi, S.

    1981-01-01

    A free radical propulsion concept utilizing the recombination energy of dissociated low molecular weight gases to produce thrust was examined. The concept offered promise of a propulsion system operating at a theoretical impulse, with hydrogen, as high as 2200 seconds at high thrust to power ratio, thus filling the gas existing between chemical and electrostatic propulsion capabilities. Microwave energy used to dissociate a continuously flowing gas was transferred to the propellant via three body recombination for conversion to propellant kinetic energy. Power absorption by the microwave plasma discharge was in excess of 90 percent over a broad range of pressures. Gas temperatures inferred from gas dynamic equations showed much higher temperatures from microwave heating than from electrothermal heating. Spectroscopic analysis appeared to corroborate the inferred temperatures of one of the gases tested.

  12. Radicals in Berkeley?

    PubMed Central

    Linn, Stuart

    2015-01-01

    In a previous autobiographical sketch for DNA Repair (Linn, S. (2012) Life in the serendipitous lane: excitement and gratification in studying DNA repair. DNA Repair 11, 595–605), I wrote about my involvement in research on mechanisms of DNA repair. In this Reflections, I look back at how I became interested in free radical chemistry and biology and outline some of our bizarre (at the time) observations. Of course, these studies could never have succeeded without the exceptional aid of my mentors: my teachers; the undergraduate and graduate students, postdoctoral fellows, and senior lab visitors in my laboratory; and my faculty and staff colleagues here at Berkeley. I am so indebted to each and every one of these individuals for their efforts to overcome my ignorance and set me on the straight and narrow path to success in research. I regret that I cannot mention and thank each of these mentors individually. PMID:25713083

  13. Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow.

    PubMed

    Müller, Simon T R; Hokamp, Tobias; Ehrmann, Svenja; Hellier, Paul; Wirth, Thomas

    2016-08-16

    Ethyl diazoacetate (EDA) is one of the most prominent diazo reagents. It is frequently used in metal-carbene-type reactions. However, EDA can also be used as a nucleophile under base catalysis. Whilst the addition of EDA to aldehydes can be performed using organic bases, the addition of EDA to other carbonyl electrophiles requires the use of organometallics such as lithium diisopropylamide (LDA). The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at low temperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields. PMID:27339757

  14. [Reaction of 1,8-naphthyridine azides with ethyl acrylate].

    PubMed

    Livi, O; Ferrarini, P L; Bertini, D; Tonetti, I

    1975-12-01

    The reaction of 1,8-naphthyridine azides with ethyl acrylate leads to the formation of 2-pyrazolines instead of 1,2,3-triazolines. Some of the compounds obtained have undergone pharmacological and microbiological (antibacterial) testing. PMID:1204828

  15. A Signature of Roaming Dynamics in the Thermal Decomposition of Ethyl Nitrite: Chirped-Pulse Rotational Spectroscopy and Kinetic Modeling.

    PubMed

    Prozument, Kirill; Suleimanov, Yury V; Buesser, Beat; Oldham, James M; Green, William H; Suits, Arthur G; Field, Robert W

    2014-11-01

    Chirped-pulse (CP) Fourier transform rotational spectroscopy is uniquely suited for near-universal quantitative detection and structural characterization of mixtures that contain multiple molecular and radical species. In this work, we employ CP spectroscopy to measure product branching and extract information about the reaction mechanism, guided by kinetic modeling. Pyrolysis of ethyl nitrite, CH3CH2ONO, is studied in a Chen type flash pyrolysis reactor at temperatures of 1000-1800 K. The branching between HNO, CH2O, and CH3CHO products is measured and compared to the kinetic models generated by the Reaction Mechanism Generator software. We find that roaming CH3CH2ONO → CH3CHO + HNO plays an important role in the thermal decomposition of ethyl nitrite, with its rate, at 1000 K, comparable to that of the radical elimination channel CH3CH2ONO → CH3CH2O + NO. HNO is a signature of roaming in this system. PMID:26278732

  16. In Vitro and in Vivo antioxidant activity of ethyl acetate extraction of purple rice.

    PubMed

    Shen, Y; Chen, L; Zhang, H; Zhang, Y; Zhang, H; Wang, L; Qian, H; Qi, X; Zhang, H

    2016-01-01

    The antioxidant activities of ethyl acetate extraction of purple rice (EAEPR) were evaluated by various methods in vitro and in vivo. In in vitro antioxidant assays, EAEPR was found to have strong 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity hydroxyl radical, reducing power and metal-ion chelating activity. In in vivo antioxidant assays, mice were administered with EAEPR via gavage for 42 consecutive days. As a result, administration of EAEPR significantly enhanced the activities of glutathione peroxidase in serums and livers of mice. EAEPR could improve the lipid status, especially total cholesterol and low-density lipoprotein cholesterol levels. In addition, total phenolic content of EAEPR was 188.21mg/g. The main phenolic compounds in EAEPR analyzed by ultra-high performance liquid chromatography tandem mass spectrometry were determined as ferulic acid and quercetin. The contents of ferulic acid and quercetin in EAEPR were 14.21mg/g and 35.28mg/g, respectively. The Nrf2 expression was significantly elevated after administration of EAEPR.These results suggested that EAEPR had potent antioxidant activity and could be explored as a novel natural antioxidant. PMID:27188742

  17. Radical Energies and the Regiochemistry of Addition to Heme Groups. Methylperoxy and Nitrite Radical Additions to the Heme of Horseradish Peroxidase

    PubMed Central

    Wojciechowski, Grzegorz; Ortiz de Montellano, Paul R.

    2008-01-01

    The heme of hemoproteins, as exemplified by horseradish peroxidase (HRP), can undergo additions at the meso carbons and/or vinyl groups of the electrophilic or radical species generated in the catalytic oxidation of halides, pseudohalides, carboxylic acids, aryl and alkyl hydrazines, and other substrates. The determinants of the regiospecificity of these reactions, however, are unclear. We report here modification of the heme of HRP by autocatalytically generated, low energy NO2• and CH3OO• radicals. The NO2• radical adds regioselectively to the 4- over the 2-vinyl group but does not add to the meso positions. Reaction of HRP with tert-BuOOH does not lead to heme modification, but reaction with the F152M mutant, in which the heme vinyls are more sterically accessible, results in conversion of the heme 2-vinyl into a 1-hydroxy-2-(methylperoxy)-ethyl group [-CH(OH)CH2OOCH3]. [18O]-labeling studies indicate that the hydroxyl group in this adduct derives from water and the methylperoxide oxygens from O2. Under anaerobic conditions, methyl radicals formed by fragmentation of the autocatalytically generated tert-BuO• radical add to both the δ-meso-carbon and the 2-vinyl group. The regiochemistry of these and the other known additions to the heme indicate that only high-energy radicals (e.g., CH3•) add to the meso-carbon. Less energetic radicals, including NO2• and CH3OO•, add to heme vinyl groups if they are small enough but do not add to the meso-carbons. Electrophilic species such as HOBr, HOCl, and HOSCN add to vinyl groups but do not react with the meso-carbons. This meso- versus vinyl-reactivity paradigm, which appears to be general for autocatalytic additions to heme prosthetic groups, suggests that meso-hydroxylation of the heme by heme oxygenase occurs by a controlled radical reaction rather than by electrophilic addition. PMID:17249668

  18. Phytochemical Analysis and Free Radical Scavenging Activity of Medicinal Plants Gnidia glauca and Dioscorea bulbifera

    PubMed Central

    Ghosh, Sougata; Derle, Abhishek; Ahire, Mehul; More, Piyush; Jagtap, Soham; Phadatare, Suvarna D.; Patil, Ajay B.; Jabgunde, Amit M.; Sharma, Geeta K.; Shinde, Vaishali S.; Pardesi, Karishma; Dhavale, Dilip D.; Chopade, Balu A.

    2013-01-01

    Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS•+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS•+ radical with a second order rate constant of 2.33×106 and 1.72×106, respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48×106 and 4.46×106 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants. PMID:24367520

  19. Anti-genotoxic and free-radical scavenging activities of extracts from (Tunisian) Myrtus communis.

    PubMed

    Hayder, N; Abdelwahed, A; Kilani, S; Ammar, R Ben; Mahmoud, A; Ghedira, K; Chekir-Ghedira, L

    2004-11-14

    The effect of extracts from leaves of Myrtus communis on the SOS reponse induced by Aflatoxin B1 (AFB1) and Nifuroxazide was investigated in a bacterial assay system, i.e. the SOS chromotest with Escherichia coli PQ37. Aqueous extract, the total flavonoids oligomer fraction (TOF), hexane, chloroform, ethyl acetate and methanol extracts and essential oil obtained from M. communis significantly decreased the SOS response induced by AFB1 (10 microg/assay) and Nifuroxazide (20 microg/assay). Ethyl acetate and methanol extracts showed the strongest inhibition of the induction of the SOS response by the indirectly genotoxic AFB1. The methanol and aqueous extracts exhibited the highest level of protection towards the SOS-induced response by the directly genotoxic Nifuroxazide. In addition to anti-genotoxic activity, the aqueous extract, the TOF, and the ethyl acetate and methanol extracts showed an important free-radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. These results suggest the future utilization of these extracts as additives in chemoprevention studies. PMID:15474415

  20. Addition reaction of alkyl radical to C60 fullerene: Density functional theory study

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto; Kawabata, Hiroshi

    2016-02-01

    Functionalized fullerenes are known as a high-performance molecules. In this study, the alkyl-functionalized fullerenes (denoted by R-C60) have been investigated by means of the density functional theory (DFT) method to elucidate the effects of functionalization on the electronic states of fullerene. Also, the reaction mechanism of alkyl radicals with C60 was investigated. The methyl, ethyl, propyl, and butyl radicals (denoted by n = 1-4, where n means the number of carbon atoms in the alkyl radical) were examined as alkyl radicals. The DFT calculation showed that the alkyl radical binds to the carbon atom of C60 at the on-top site, and a strong C-C single bond is formed. The binding energies of alkyl radicals to C60 were distributed in the range of 31.8-35.1 kcal mol-1 at the CAM-B3LYP/6-311G(d,p) level. It was found that the activation barrier exists before alkyl addition, the barrier heights were calculated to be 2.1-2.8 kcal mol-1. The electronic states of R-C60 complexes were discussed on the basis of the theoretical results.

  1. The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings

    SciTech Connect

    Buckingham, Grant T.; Ormond, Thomas K.; Porterfield, Jessica P.; Ellison, G. Barney; Hemberger, Patrick; Kostko, Oleg; Ahmed, Musahid; Robichaud, David J.; Nimlos, Mark R.; Daily, John W.

    2015-01-28

    The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C{sub 6}H{sub 5}CH{sub 2}, as well as a set of isotopically labeled radicals: C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2}. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C{sub 5}H{sub 4}=C=CH{sub 2}, H atom, C{sub 5}H{sub 4}—C ≡ CH, C{sub 5}H{sub 5}, HCCCH{sub 2}, and HC ≡ CH. Pyrolysis of the C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2} benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C{sub 6}H{sub 5}CH{sub 2}⇋C{sub 7}H{sub 7}. These labeling studies suggest that there must be other thermal decomposition routes for the C{sub 6}H{sub 5}CH{sub 2} radical that differ from the fulvenallene pathway.

  2. Antibacterial polypropylene via surface-initiated atom transfer radical polymerization.

    PubMed

    Huang, Jinyu; Murata, Hironobu; Koepsel, Richard R; Russell, Alan J; Matyjaszewski, Krzysztof

    2007-05-01

    Polypropylene (PP) coated by a non-leachable biocide was prepared by chemically attaching poly(quaternary ammonium) (PQA) to the surface of PP. The well-defined poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), a precursor of PQA, was grown from the surface of PP via atom transfer radical polymerization (ATRP). The tertiary ammine groups in PDMAEMA were consequently converted to QA in the presence of ethyl bromide. Successful surface modification was confirmed by ATR-FTIR, contact angle measurement, and an antibacterial activity test against Escherichia coli (E. coli). The biocidal activity of the resultant surfaces depends on the amount of the grafted polymers (the number of available quaternary ammonium units). With the same grafting density, the surface grafted with relatively high MW polymers (M(n) > 10,000 g/mol) showed almost 100% killing efficiency (killing all of the input E. coli (2.9 x 10(5)) in the shaking test), whereas a low biocidal activity (85%) was observed for the surface grafted with shorter PQA chains (M(n) = 1,500 g/mol). PMID:17417906

  3. Peroxy radical partitioning during the AMMA radical intercomparison exercise

    NASA Astrophysics Data System (ADS)

    Andrés-Hernández, M. D.; Stone, D.; Brookes, D. M.; Commane, R.; Reeves, C. E.; Huntrieser, H.; Heard, D. E.; Monks, P. S.; Burrows, J. P.; Schlager, H.; Kartal, D.; Evans, M. J.; Floquet, C. F. A.; Ingham, T.; Methven, J.; Parker, A. E.

    2010-11-01

    Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis) campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE) and total peroxy radicals (RO2* = HO2+ΣRO2, R = organic chain) by two similar instruments based on the peroxy radical chemical amplification (PeRCA) technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously. Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

  4. Peroxy radical partitioning during the AMMA radical intercomparison exercise

    NASA Astrophysics Data System (ADS)

    Andrés-Hernández, M. D.; Stone, D.; Brookes, D. M.; Commane, R.; Reeves, C. E.; Huntrieser, H.; Heard, D. E.; Monks, P. S.; Burrows, J. P.; Schlager, H.; Kartal, D.; Evans, M. J.; Floquet, C. F. A.; Ingham, T.; Methven, J.; Parker, A. E.

    2010-04-01

    Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis) campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE) and total peroxy radicals (RO2*=HO2+ΣRO2, R= organic chain) by two similar instruments based on the peroxy radical chemical amplification (PerCA) technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously. Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

  5. [Formation of ethyl carbamate in umeshu (plum liqueur)].

    PubMed

    Suzuki, K; Kamimura, H; Ibe, A; Tabata, S; Yasuda, K; Nishijima, M

    2001-12-01

    Samples of umeshu, a Japanese plum liqueur made from unripe plums, shochu and crystal sugar, were stored under fluorescent light, in the dark and in the refrigerator. The amount of ethyl carbamate formed in umeshu exposed to light or room temperature was larger than that in the dark or at low temperature. The amount of ethyl carbamate formed in umeshu to which cyanide had been added was larger than that in the absence of added cyanide. Thus, the amount of ethyl carbamate formed in the umeshu was increased by not only light and higher temperature, but also cyanide. Samples of model alcoholic beverages were stored under various conditions using red, yellow and blue cellophanes. The amount of ethyl carbamate formed in the model alcoholic beverage with blue cellophane was larger than in the cases of red and yellow cellophanes. It was found that the amount of ethyl carbamate formed in the model alcoholic beverage was increased by light in the wavelength range of 375-475 nm. PMID:11875819

  6. School Finance-Radical Departure.

    ERIC Educational Resources Information Center

    Kimple, James

    1983-01-01

    It is proposed that New Jersey assume approximately 70 percent of the cost of its public schools. Several other proposals are presented, all a radical departure from current school funding practices. (BW)

  7. Free radical inactivation of pepsin

    NASA Astrophysics Data System (ADS)

    Josimović, Lj; Ruvarac, I.; Janković, I.; Jovanović, S. V.

    1994-06-01

    Alkylperoxy radicals containing one, two or three chlorine atoms, CO -2, O 2 - were reacted with pepsin in aqueous solutions. It was found that only Cl 3COO and CO -2 inactive pepsin, attacking preferentially the disulfide bridge. Transient spectra obtained upon completion of the Cl 3COO + pepsin reaction at pH 5 indicate that 20% of initially produced Cl 3COO radicals oxidizes tryptophan residues, and 40% disulfide bridges. The inactivation induced by the Cl 3COO radical increases at lower pH, and the maximal inactivation, Gin = 5.8, was observed at pH 1.5. The inactivation of pepsin by CO -2 radicals depends on the absorbed dose. The maximal inactivation, Gin = 4.5, was determined in the dose range from 38 to 53 Gy.

  8. Redox Properties of Free Radicals.

    ERIC Educational Resources Information Center

    Neta, P.

    1981-01-01

    Describes pulse radiolysis as a useful means in studing one-electron redox potentials. This method allows the production of radicals and the determination of their concentration and rates of reaction. (CS)

  9. [Alcohol and free oxygen radicals].

    PubMed

    Mira, M L; Manso, C F

    1993-05-01

    Oxygen free radicals may be generated during ethanol metabolization by cytochrome P450, or due to the formation of xanthine oxidase by ethanol effect on xanthine dehydrogenase. After transformation into acetaldehyde, the metabolism of this compound by xanthine oxidase or by aldehyde oxidase also generates oxygen radicals. We present the hypothesis of a vicious cycle during ethanol metabolization by aldehyde oxidase, which would amplify the process and be responsible for an increased degree of lipid peroxidation. PMID:8393265

  10. Antioxidant potential and radical scavenging effects of various extracts from Abutilon indicum and Abutilon muticum.

    PubMed

    Yasmin, Sammia; Kashmiri, Muhammad Akram; Asghar, Muhammad Nadeem; Ahmad, Mushtaq; Mohy-ud-Din, Ayesha

    2010-03-01

    Abutilon indicum L. (Malvaceae) and Abutilon muticum DC. (Malvaceae) are traditional medicinal herbs used for analgesic, anthelmintic, hepatoprotective, and hypoglycemic properties. These effects may be correlated with the presence of antioxidant compounds. Extracts in organic solvents from the aerial parts and roots of both species were prepared and evaluated for their total antioxidant capacity (TAC), total phenolic content, and total flavonoid content. The Trolox equivalent antioxidant capacity (TEAC) of all the extracts of both plants was found, employing ABTS and FRAP assays. TEAC values ranged from 3.019 to 10.5 muM for n-hexane and butanol fractions of Abutilon indicum and from 2.247 to 14.208 muM for n-hexane and butanol fractions of Abutilon muticum, respectively, using the ABTS assay. The FRAP assay showed reducing powers of the fractions in the order of butanol > ethyl acetate > chloroform > n-hexane and butanol > chloroform > hexane > ethyl acetate for Abutilon indicum and Abutilon muticum, respectively. EC(50) and T(EC50) values for the extracts of both plants were determined using the DPPH free radical assay. The reaction kinetics with this free radical indicated the presence of both slow reacting and fast reacting antioxidant components in the extracts of both plants. The antioxidant/radical scavenging capacity of the extracts was found to be a dose-dependent activity. The results obtained in the present study indicate that both Abutilon species are potential sources of natural antioxidants. PMID:20645814

  11. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. 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-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE 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 AAASAE in fragrances. PMID:22414652

  12. NEW GROUND-STATE MEASUREMENTS OF ETHYL CYANIDE

    SciTech Connect

    Brauer, Carolyn S.; Pearson, John C.; Drouin, Brian J.; Yu, Shanshan

    2009-09-01

    The spectrum of ethyl cyanide, or propionitrile (CH{sub 3}CH{sub 2}CN), has been repeatedly observed in the interstellar medium with large column densities and surprisingly high temperatures in hot core sources. The construction of new, more sensitive, observatories accessing higher frequencies such as Herschel, ALMA, and SOFIA have made it important to extend the laboratory data for ethyl cyanide to coincide with the capabilities of the new instruments. We report extensions of the laboratory measurements of the rotational spectrum of ethyl cyanide in its ground vibrational state to 1.6 THz. A global analysis of the ground state, which includes all of the previous data and 3356 newly assigned transitions, has been fitted to within experimental error to J = 132, K = 36, using both Watson A-reduced and Watson S-reduced Hamiltonians.

  13. Nitrosamine-induced carcinogenesis. The alkylation of N-7 of guanine of nucleic acids of the rat by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate

    PubMed Central

    Swann, P. F.; Magee, P. N.

    1971-01-01

    1. The extent of ethylation of N-7 of guanine in the nucleic acids of rat tissue in vivo by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate was measured. 2. All compounds produced measurable amounts of 7-ethyl-guanine. 3. A single dose of diethylnitrosamine or N-ethyl-N-nitrosourea produced tumours of the kidney in the rat. Three doses of ethyl methanesulphonate produced kidney tumours, but a single dose did not. 4. A single dose of diethylnitrosamine produced twice as much ethylation of N-7 of guanine in DNA of kidney as did N-ethyl-N-nitrosourea. A single dose of both compounds induced kidney tumours, although of a different histological type. 5. A single dose of ethyl methanesulphonate produced ten times as much ethylation of N-7 of guanine in kidney DNA as did N-ethyl-N-nitrosourea without producing tumours. 6. The relevance of these findings to the hypothesis that alkylation of a cellular component is the mechanism of induction of tumours by nitroso compounds is discussed. PMID:5145908

  14. Assistance of ethyl glucuronide and ethyl sulfate in the interpretation of postmortem ethanol findings.

    PubMed

    Krabseth, Hege; Mørland, Jørg; Høiseth, Gudrun

    2014-09-01

    Postmortem ethanol formation is a well-known problem in forensic toxicology. The aim of this study was to interpret findings of ethanol in blood, in a large collection of forensic autopsy cases, by use of the nonoxidative ethanol metabolites, ethyl glucuronide (EtG), and ethyl sulfate (EtS). In this study, according to previously published literature, antemortem ethanol ingestion was excluded in EtS-negative cases. Among 493 ethanol-positive forensic autopsy cases, collected during the study period, EtS was not detected in 60 (12 %) of the cases. Among cases with a blood alcohol concentration (BAC) of ≤ 0.54 g/kg, antemortem ethanol ingestion was excluded in 38 % of the cases, while among cases with a BAC of ≥ 0.55 g/kg, antemortem ethanol ingestion was excluded in 2.2 % of the cases. For all cases where ethanol was measured at a concentration >1.0 g/kg, EtS was detected. The highest blood ethanol concentration in which EtS was not detected was 1.0 g/kg. The median concentrations of EtG and EtS in blood were 9.5 μmol/L (range: not detected (n.d.) 618.1) and 9.2 μmol/L (range: n.d. 182.5), respectively. There was a statistically significant positive correlation between concentration levels of ethanol and of EtG (Spearman's rho=0.671, p<0.001) and EtS (Spearman's rho=0.670, p<0.001), respectively. In conclusion, this study showed that in a large number of ethanol-positive forensic autopsy cases, ethanol was not ingested before the time of death, particularly among cases where ethanol was present in lower blood concentrations. Routine measurement of EtG and EtS should therefore be recommended, especially in cases with BAC below 1 g/kg. PMID:24935750

  15. Blood kinetics of ethyl glucuronide and ethyl sulphate in heavy drinkers during alcohol detoxification.

    PubMed

    Høiseth, Gudrun; Morini, Luca; Polettini, Aldo; Christophersen, Asbjørg; Mørland, Jørg

    2009-07-01

    Studies of ethyl glucuronide (EtG) blood kinetics have so far been performed on healthy volunteers with ingestion of low to moderate doses of ethanol. These data are not necessarily transferable to heavy drinkers where the consumed doses of ethanol are much higher. The aim of this study was to investigate the pharmacokinetics of EtG and ethyl sulphate (EtS) in blood in heavy drinkers after termination of alcohol ingestion. Sixteen patients from an alcohol withdrawal clinic were included directly after admission. Time of end of drinking, estimated daily intake of ethanol (EDI) and medical history were recorded. Three to five blood samples over 20-43 h were collected from each patient subsequent to admission. The median EDI was 172 g (range 60-564). The first sample was collected median 2.5 h after end of drinking (range 0.5-23.5). Two patients had levels of EtG and EtS below LOQ in all samples, the first collected 19.25 and 23.5 h after cessation of drinking, respectively. Of the remaining 14 patients, one subject, suffering from both renal and hepatic disease, showed concentrations of EtG and EtS substantially higher than the rest of the material. This patient's initial value of EtG was 17.9 mg/L and of EtS 5.9 mg/L, with terminal elimination half lives of 11.9 h for EtG and 12.5 h for EtS. Among the remaining 13 patients, the initial median values were 0.7 g/L (range 0-3.7) for ethanol, 1.7 mg/L (range 0.1-5.9) for EtG and 0.9 mg/L (range 0.1-1.9) for EtS. Elimination occurred with a median half-life of 3.3 h for EtG (range 2.6-4.3) and 3.6 h for EtS (range 2.7-5.4). In conclusion, elimination of EtG in heavy drinkers did not significantly differ from healthy volunteers, and EtS appeared to have similar elimination rate. In the present work, there was one exception to this, and we propose that this could be explained by the patient's renal disease, which would delay excretion of these conjugated metabolites. PMID:19395207

  16. Crystalline bipyridinium radical complexes and uses thereof

    DOEpatents

    Fahrenbach, Albert C.; Barnes, Jonathan C.; Li, Hao; Stoddart, J. Fraser; Basuray, Ashish Neil; Sampath, Srinivasan

    2015-09-01

    Described herein are methods of generating 4,4'-bipyridinium radical cations (BIPY.sup..cndot.+), and methods for utilizing the radical-radical interactions between two or more BIPY.sup..cndot.+ radical cations that ensue for the creation of novel materials for applications in nanotechnology. Synthetic methodologies, crystallographic engineering techniques, methods of physical characterization, and end uses are described.

  17. Steric Effects in the Reaction of Aryl Radicals on Surfaces

    SciTech Connect

    Combellas, Catherine; Jiang, Deen; Kanoufi, Frederic; Pinson, Jean; Podvorica, Fetah

    2009-01-01

    Steric effects are investigated in the reaction of aryl radicals with surfaces. The electrochemical reduction of 2-, 3-, 4-methyl, 2-methoxy, 2-ethyl, 2,6-, 2,4-, and 3,5-dimethyl, 4-tert-butyl, 3,5-bis-tert-butyl benzenediazonium, 3,5-bis(trifluoromethyl), and pentafluoro benzenediazonium tetrafluoroborates is examined in acetonitrile solutions. It leads to the formation of grafted layers only if the steric hindrance at the 2- or 2,6-position(s) is small. When the 3,5-positions are crowded with tert-butyl groups, the growth of the organic layer is limited by steric effects and a monolayer is formed. The efficiency of the grafting process is assessed by cyclic voltammetry, X-ray photoelectron spectroscopy, infrared, and ellipsometry. These experiments, together with density functional computations of bonding energies of substituted phenyl groups on a copper surface, are discussed in terms of the reactivity of aryl radicals in the electrografting reaction and in the growth of the polyaryl layer.

  18. Ethyl glucuronide and ethyl sulfate in meconium and hair-potential biomarkers of intrauterine exposure to ethanol.

    PubMed

    Morini, L; Marchei, E; Vagnarelli, F; Garcia Algar, O; Groppi, A; Mastrobattista, L; Pichini, S

    2010-03-20

    This study investigated ethyl glucuronide (EtG) and ethyl sulfate (EtS) concentration in meconium and in maternal and neonatal hair (HEtG and HFAEEs, respectively) as potential markers of intrauterine exposure to ethanol together with meconium fatty acid ethyl esters (FAEEs) in a cohort of 99 mother-infant dyads, 49 coming from the Arcispedale of Reggio Emilia (Italy) and 50 from the Hospital del Mar of Barcelona (Spain). FAEEs, EtG and EtS were measured in meconium samples using liquid chromatography-tandem mass spectrometry. A head space-solid phase microextraction-gas chromatography-mass spectrometry was used to test HEtG and HFAEEs in hair samples from mothers and their newborns. Eighty-two meconium samples (82.8%) tested positive for EtG, 19 (19.2%) for EtS while 22 (22.2%) showed FAEEs levels higher than 2 nmol/g, the cut-off used to differentiate daily maternal ethanol consumption during pregnancy from occasional or no use. Although EtG and EtS in meconium did not correlate with total FAEEs concentration, a good correlation between EtG, EtS and ethyl stearate was observed. Moreover, EtG correlated well with ethyl palmitoleate, while EtS with ethyl laurate, myristate and linolenate. Neither maternal nor neonatal hair appears as good predictors of gestational ethanol consumption and subsequent fetal exposure in these mother-infant dyads. In conclusion, these data show that meconium is so far the best matrix in evaluating intrauterine exposure to ethanol, with EtG and EtS being potentially good alternative biomarkers to FAEEs. PMID:20060246

  19. Standard Electrode Potentials Involving Radicals in Aqueous Solution: Inorganic Radicals

    SciTech Connect

    Armstrong, David A.; Huie, Robert E.; Koppenol, Willem H.; Lymar, Sergei V.; Merenyi, Gabor; Neta, Pedatsur; Ruscic, Branko; Stanbury, David M.; Steenken, Steen; Wardman, Peter

    2015-12-01

    Recommendations are made for standard potentials involving select inorganic radicals in aqueous solution at 25 °C. These recommendations are based on a critical and thorough literature review and also by performing derivations from various literature reports. The recommended data are summarized in tables of standard potentials, Gibbs energies of formation, radical pKa’s, and hemicolligation equilibrium constants. In all cases, current best estimates of the uncertainties are provided. An extensive set of Data Sheets is appended that provide original literature references, summarize the experimental results, and describe the decisions and procedures leading to each of the recommendations

  20. Mechanically Stabilized Tetrathiafulvalene Radical Dimers

    SciTech Connect

    Coskun, Ali; Spruell, Jason M.; Barin, Gokhan; Fahrenbach, Albert C.; Forgan, Ross S.; Colvin, Michael T.; Carmieli, Raanan; Benitez, Diego; Tkatchouk, Ekaterina; Friedman, Douglas C.; Sarjeant, Amy A.; Wasielewski, Michael R.; Goddard, William A.; Stoddart, J. Fraser

    2011-01-01

    Two donor-acceptor [3]catenanes—composed of a tetracationic molecular square, cyclobis(paraquat-4,4'-biphenylene), as the π-electron deficient ring and either two tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP) containing macrocycles or two TTF-butadiyne-containing macrocycles as the π-electron rich components—have been investigated in order to study their ability to form TTF radical dimers. It has been proven that the mechanically interlocked nature of the [3]catenanes facilitates the formation of the TTF radical dimers under redox control, allowing an investigation to be performed on these intermolecular interactions in a so-called “molecular flask” under ambient conditions in considerable detail. In addition, it has also been shown that the stability of the TTF radical-cation dimers can be tuned by varying the secondary binding motifs in the [3]catenanes. By replacing the DNP station with a butadiyne group, the distribution of the TTF radical-cation dimer can be changed from 60% to 100%. These findings have been established by several techniques including cyclic voltammetry, spectroelectrochemistry and UV-vis-NIR and EPR spectroscopies, as well as with X-ray diffraction analysis which has provided a range of solid-state crystal structures. The experimental data are also supported by high-level DFT calculations. The results contribute significantly to our fundamental understanding of the interactions within the TTF radical dimers.

  1. 40 CFR 799.2700 - Methyl ethyl ketoxime.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Specific Chemical Test Rules § 799.2700 Methyl ethyl ketoxime. (a) Identification of test substance. (1... signs of cytotoxicity (e.g., a change in the ratio of polychromatic to normochromatic erythrocytes)...

  2. 40 CFR 799.2700 - Methyl ethyl ketoxime.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Specific Chemical Test Rules § 799.2700 Methyl ethyl ketoxime. (a) Identification of test substance. (1... signs of cytotoxicity (e.g., a change in the ratio of polychromatic to normochromatic erythrocytes)...

  3. 40 CFR 799.2700 - Methyl ethyl ketoxime.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Methyl ethyl ketoxime. 799.2700 Section 799.2700 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Specific Chemical Test Rules § 799.2700...

  4. 76 FR 31479 - Pyraflufen-ethyl; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Federal Register of June 23, 2010 (75 FR 35801) (FRL-8831- 3), EPA issued a notice pursuant to section 408...- ethyl. C. Revisions to Petitioned-for Tolerances In the Federal Register of December 8, 2010 (75 FR..., entitled Regulatory Planning and Review (58 FR 51735, ] October 4, 1993). Because this final rule has...

  5. 77 FR 41346 - Trinexapac-ethyl; Proposed Pesticide Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... tolerance table for trinexapac-ethyl that was published in the Federal Register on March 2, 2012 (77 FR... Planning and Review'' (58 FR 51735, October 4, 1993). Because this proposed rule has been exempted from..., Distribution, or Use'' (66 FR 28355, May 22, 2001). This proposed rule does not contain any...

  6. Synthesis of Ethyl Nalidixate: A Medicinal Chemistry Experiment

    ERIC Educational Resources Information Center

    Leslie, Ray; Leeb, Elaine; Smith, Robert B.

    2012-01-01

    A series of laboratory experiments that complement a medicinal chemistry lecture course in drug design and development have been developed. The synthesis of ethyl nalidixate covers three separate experimental procedures, all of which can be completed in three, standard three-hour lab classes and incorporate aspects of green chemistry such as…

  7. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  8. Enantioselective Metabolism of Quizalofop-Ethyl in Rat

    PubMed Central

    Liang, Yiran; Wang, Peng; Liu, Donghui; Shen, Zhigang; Liu, Hui; Jia, Zhixin; Zhou, Zhiqiang

    2014-01-01

    The pharmacokinetic and distribution of the enantiomers of quizalofop-ethyl and its metabolite quizalofop-acid were studied in Sprague-Dawley male rats. The two pairs of enantiomers were determined using a validated chiral high-performance liquid chromatography method. Animals were administered quizalofop-ethyl at 10 mg kg−1 orally and intravenously. It was found high concentration of quizalofop-acid in the blood and tissues by both intragastric and intravenous administration, and quizalofop-ethyl could not be detected through the whole study which indicated a quick metabolism of quizalofop-ethyl to quizalofop-acid in vivo. In almost all the samples, the concentrations of (+)-quizalofop-acid exceeded those of (−)-quizalofop-acid. Quizalofop-acid could still be detected in the samples even at 120 h except in brain due to the function of blood-brain barrier. Based on a rough calculation, about 8.77% and 2.16% of quizalofop-acid were excreted through urine and feces after intragastric administration. The oral bioavailability of (+)-quizalofop-acid and (−)-quizalofop-acid were 72.8% and 83.6%. PMID:24964043

  9. Synthesis and degradation behavior of poly(ethyl cyanoacrylate)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poly(ethyl cyanoacrylate) was synthesized using N, N'-dimethyl-p-toulidine (DMPT) as an initiator through anionic/zwitterionic pathway. The degradability and the degradation mechanism of the prepared polymers were carefully examined from various points of views. It was found that the polymers were...

  10. Synthesis and self-assembly of terpyridine end-capped poly(N-isopropylacrylamide)-block-poly(2-(dimethylamino)ethyl methacrylate) diblock copolymers.

    PubMed

    Brassinne, Jérémy; Poggi, Elio; Fustin, Charles-André; Gohy, Jean-François

    2015-04-01

    At the basis of smart self-assembled materials are lying small building blocks that can hierarchically assemble in response to stimuli, e.g., temperature or chemical species. In this context, the synthesis of terpyridine end-capped poly(2-(dimethylamino)ethyl methacrylate)-block-poly(N-isopropylacrylamide) diblock copolymers via controlled radical copolymerization is reported here. The self-assembly of those copolymers is investigated in dilute aqueous solutions while varying temperature or adding transition metal ions, respectively, leading to the formation of micellar nanostructures or metallosupramolecular triblock copolymers. PMID:25491079

  11. Radical-Mediated Enzymatic Polymerizations

    PubMed Central

    Zavada, Scott R.; Battsengel, Tsatsral; Scott, Timothy F.

    2016-01-01

    Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes―catalytic proteins―owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol–ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

  12. Epistemological barriers to radical behaviorism

    PubMed Central

    O'Donohue, William T.; Callaghan, Glenn M.; Ruckstuhl, L. E.

    1998-01-01

    The historian and philosopher of science Gaston Bachelard proposed the concept of epistemological barriers to describe the intellectual challenges encountered by scientists in their work. In order to embrace novel ways of approaching a problem in science, scientists must overcome barriers or obstacles posed by their prior views. For example, Einsteinian physics presents scientists with claims that space is curved and that time and space are on the same continuum. We utilize Bachelard's concept of epistemological barriers to describe the differences between the intellectual journeys students pursuing advanced studies face when attempting to accept cognitive psychology or radical behaviorism. We contend that the folk psychological beliefs that students typically hold when entering these studies pose less challenge to cognitive psychology than to radical behaviorism. We also suggest that these barriers may also partly be involved in the problematic exegesis that has plagued radical behaviorism. In close, we offer some suggestions for dealing with these epistemological barriers. PMID:22478314

  13. Free radical decay in adamantane

    SciTech Connect

    Tegowski, A.T.; Pratt, D.W.

    1984-01-11

    Kinetic electron paramagnetic resonance (EPR) techniques have been used to characterize the decay behavior of the ''stable'' free radical 2-cyclohexanonyl in the plastic crystal phase f an adamantane matrix over the temperature range 257-313 K. Typical plots of the EPR signal intensity as a function of time are biexponential in nature, suggesting the existence of at least two channels for free radical decay. The activation parameters for both processes have been measured in both protonated and deuterated samples. A comparison of these results with those in other systems suggests that the host does, as expected, considerably reduce the pre-exponential factors for decay of the radical by bimolecular processes but has relatively little influence on the corresponding activation energies. 3 figures.

  14. Radical-Mediated Enzymatic Polymerizations.

    PubMed

    Zavada, Scott R; Battsengel, Tsatsral; Scott, Timothy F

    2016-01-01

    Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes--catalytic proteins--owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol-ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

  15. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including...

  16. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including...

  17. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including...

  18. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... combined residues of the herbicide fenoxaprop-ethyl phenoxy]propanoate] and its metabolites (6-chloro-2... tolerances are established for combined residues of the herbicide fenoxaprop-ethyl, phenoxy]propanoic...

  19. Donor free radical explosive composition

    DOEpatents

    Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

    1980-04-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

  20. Antioxidant and antimicrobial activities of ethyl acetate extract, fractions and compounds from stem bark of Albizia adianthifolia (Mimosoideae)

    PubMed Central

    2012-01-01

    Background Albizia adianthifolia is used traditionally in Cameroon to treat several ailments, including infectious and associated diseases. This work was therefore designed to investigate the antioxidant and antimicrobial activities of ethyl acetate extract, fractions and compounds isolated from the stem bark of this plant. Methods The plant extract was prepared by maceration in ethyl acetate. Its fractionation was done by column chromatography and the structures of isolated compounds were elucidated using spectroscopic data in conjunction with literature data. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and trolox equivalent antioxidant capacity (TEAC) assays were used to detect the antioxidant activity. Broth micro-dilution method was used for antimicrobial test. Total phenol content was determined spectrophotometrically in the extracts by using Folin–Ciocalteu method. Results The fractionation of the extract afforded two known compounds: lupeol (1) and aurantiamide acetate (2) together with two mixtures of fatty acids: oleic acid and n-hexadecanoic acid (B1); n-hexadecanoic acid, octadecanoic acid and docosanoic acid (B2). Aurantiamide acetate was the most active compound. The total phenol concentration expressed as gallic acid equivalents (GAE) was found to vary from 1.50 to 13.49 μg/ml in the extracts. The antioxidant activities were well correlated with the total phenol content (R2 = 0.946 for the TEAC method and R2 = 0.980 for the DPPH free-radical scavenging assay). Conclusions Our results clearly reveal that the ethyl acetate extract from the stem bark of A. adianthifolia possesses antioxidant and antimicrobial principles. The antioxidant activity of this extract as well as that of compound 2 are being reported herein for the first time. These results provide promising baseline information for the potential use of this plant as well as compound 2 in the treatment of oxidative damage and infections associated with the studied microorganisms. PMID

  1. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  2. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  3. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  4. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  5. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its... established for residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or...

  6. 40 CFR 180.570 - Isoxadifen-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of isoxadifen-ethyl (ethyl 5,5-diphenyl-2-isoxazoline-3-carboxylate, (CAS No. 163520-33-0), and...-isoxazolecarboxylic acid, 4,5-dihydro-5,5-diphenyl-, ethyl ester (CAS No. 164520-33-0)), and its metabolites...

  7. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethyl silicate, reaction products...

  8. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethyl silicate, reaction products...

  9. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethyl silicate, reaction products...

  10. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethyl silicate, reaction products...

  11. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethyl silicate, reaction products...

  12. 40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester... Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, ethenyl ester...

  13. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  14. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  15. 40 CFR 180.662 - Trinexapac-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Trinexapac-ethyl; tolerances for... § 180.662 Trinexapac-ethyl; tolerances for residues. (a) General. Tolerances are established for residues of the plant growth inhibitor, trinexapac-ethyl, including its metabolites and degradates, in...

  16. Students' Ideas and Radical Constructivism

    ERIC Educational Resources Information Center

    Sánchez Gómez, Pedro J.

    2016-01-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of "narrow mental states"; that is, the idea that the mental content of an individual can be fully characterised without…

  17. Robot-assisted radical cystectomy.

    PubMed

    Kurpad, Raj; Woods, Michael

    2015-12-01

    Robot-assisted radical cystectomy (RARC) has rapidly penetrated the field of urology since its inception in 2003. Several observational studies, retrospective reports, and three randomized controlled trials (RCT) have preliminarily demonstrated the safety and efficacy of (RARC). Additionally, results from the RAZOR RCT will be available in 2016-2017 to better substantiate the use of (RARC). PMID:26310514

  18. Free radicals, antioxidants, and nutrition.

    PubMed

    Fang, Yun-Zhong; Yang, Sheng; Wu, Guoyao

    2002-10-01

    Radiation hazards in outer space present an enormous challenge for the biological safety of astronauts. A deleterious effect of radiation is the production of reactive oxygen species, which result in damage to biomolecules (e.g., lipid, protein, amino acids, and DNA). Understanding free radical biology is necessary for designing an optimal nutritional countermeasure against space radiation-induced cytotoxicity. Free radicals (e.g., superoxide, nitric oxide, and hydroxyl radicals) and other reactive species (e.g., hydrogen peroxide, peroxynitrite, and hypochlorous acid) are produced in the body, primarily as a result of aerobic metabolism. Antioxidants (e.g., glutathione, arginine, citrulline, taurine, creatine, selenium, zinc, vitamin E, vitamin C, vitamin A, and tea polyphenols) and antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidases) exert synergistic actions in scavenging free radicals. There has been growing evidence over the past three decades showing that malnutrition (e.g., dietary deficiencies of protein, selenium, and zinc) or excess of certain nutrients (e.g., iron and vitamin C) gives rise to the oxidation of biomolecules and cell injury. A large body of the literature supports the notion that dietary antioxidants are useful radioprotectors and play an important role in preventing many human diseases (e.g., cancer, atherosclerosis, stroke, rheumatoid arthritis, neurodegeneration, and diabetes). The knowledge of enzymatic and non-enzymatic oxidative defense mechanisms will serve as a guiding principle for establishing the most effective nutrition support to ensure the biological safety of manned space missions. PMID:12361782

  19. Radical Coupling Mechanisms in Lignification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechansim by which lignification, the polymerization process by which lignins are formed, is via combinatorial radical coupling reactions. Understanding such reactions allows the range of structures in lignins to be understood, and the ability of lignins to accommodate various phenolic precursor...

  20. The Other Women: Radicalizing Feminism.

    ERIC Educational Resources Information Center

    Puigvert, Lidia; Darder, Antonia; Merrill, Barbara; de los Reyes, Eileen; Stromquist, Nelly

    A recent international symposium on radicalizing feminism explored ways of developing a dialogic feminism that emphasizes working in different settings under the common goal of including women who have been invisible in the dominant feminist literature by furthering theories and practices based on the principles of dialogic feminism. The seminar…

  1. Ethyl Pyruvate Ameliorates The Damage Induced by Cyclophosphamide on Adult Mice Testes

    PubMed Central

    Bakhtiary, Zahra; Shahrooz, Rasoul; Ahmadi, Abbas; Soltanalinejad, Farhad

    2016-01-01

    Background Cyclophosphamide (CP) is a chemotherapy drug which causes deleterious effects on testicular tissue and increases free radicals in the body. The aim of this study is to investigate the protective effects of ethyl pyruvate (EP) on testicular improvement in CP treated animals. Materials and Methods In this experimental study, 15 male mice (6-8 weeks) were divided into 3 groups. The control group received normal saline (0.1 ml/day), intraperitoneal (IP), CP group received CP (15 mg/kg/week, IP), and the CP+EP group received EP (40 mg/kg/day, IP) plus CP. After 35 days, we assessed serum total antioxidant capacity (TAC) along with histomorphometric and histochemical analyses of the testicles. Results The mean thickness of the germinal epithelium, diameter of seminiferous tubules, and the number of Leydig cells in the CP+EP group were higher than those of the CP group (P<0.05). The number of the mast cells in the CP+EP group significantly reduced compared with the CP group (P<0.05). Alkaline phosphatase (ALP), periodic acid-schiff (PAS) positive reactions and lipid granules in cytoplasm of the Leydig cells in the CP group increased compared with the other groups (P<0.05). TAC in the CP group significantly reduced compared with the other groups (P<0.05). Conclusion This study showed the ability of EP to reduce the destructive side effects of CP in the adult mice reproductive system. PMID:27123204

  2. Dual responsive pickering emulsion stabilized by poly[2-(dimethylamino)ethyl methacrylate] grafted cellulose nanocrystals.

    PubMed

    Tang, Juntao; Lee, Micky Fu Xiang; Zhang, Wei; Zhao, Boxin; Berry, Richard M; Tam, Kam C

    2014-08-11

    A weak polyelectrolyte, poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), was grafted onto the surface of cellulose nanocrystals via free radical polymerization. The resultant suspension of PDMAEMA-grafted-cellulose nanocrystals (PDMAEMA-g-CNC) possessed pH-responsive properties. The grafting was confirmed by FTIR, potentiometric titration, elementary analysis, and thermogravimetric analysis (TGA); the surface and interfacial properties of the modified particles were characterized by surface tensiometer. Compared to pristine cellulose nanocrystals, modified CNC significantly reduced the surface and interfacial tensions. Stable heptane-in-water and toluene-in-water emulsions were prepared with PDMAEMA-g-CNC. Various factors, such as polarity of solvents, concentration of particles, electrolytes, and pH, on the properties of the emulsions were investigated. Using Nile Red as a florescence probe, the stability of the emulsions as a function of pH and temperature was elucidated. It was deduced that PDMAEMA chains promoted the stability of emulsion droplets and their chain conformation varied with pH and temperature to trigger the emulsification and demulsification of oil droplets. Interestingly, for heptane system, the macroscopic colors varied depending on the pH condition, while the color of the toluene system remained the same. Reversible emulsion systems that responded to pH were observed and a thermoresponsive Pickering emulsion system was demonstrated. PMID:24983405

  3. Infectious Morbidity After Radical Vulvectomy

    PubMed Central

    Carson, Linda F.; Brooker, Doris C.; Carter, Jonathan R.; Twiggs, Leo B.

    1994-01-01

    Objective: This retrospective investigation describes the infectious morbidity of patients following radical vulvectomy with or without inguinal lymph node dissection. Methods: The charts of patients undergoing radical vulvectomy between January 1, 1986, and September 1, 1989, were reviewed for age, weight, cancer type, tumor stage, operative procedure(s), prophylactic antibiotic and its length of use, febrile morbidity, infection site, culture results, significant medical history, and length of use and number of drains or catheters used. Results: The study group was composed of 61 patients, 14 of whom underwent a radical vulvectomy and 47 who also had inguinal lymph node dissection performed. Twenty-nine patients (48%) had at least 1 postoperative infection. Five patients (8%) had 2 or more postoperative infections. The site and incidence of the infections were as follows: urinary tract 23%, wound 23%, lymphocyst 3%, lymphatics (lymphangitis) 5%, and bowel (pseudomembranous colitis) 3%. The most common pathogens isolated from both urine and wound sites were Pseudomonas aeruginosa, enterococcus, and Escherichia coli. A significant decrease in wound infection was demonstrated when separate incisions were made for inguinal lymph node dissection (P <0.05). The mean number of days to onset of postoperative infection for wound, urine, lymphatics, lymphocyst, and bowel were 11, 8, 57, 48, and 5, respectively. Conclusions: We conclude that the clinical appearance of post-radical vulvectomy infections is delayed when compared with other post-surgical wound infections. Second, utilizing separate inguinal surgical incisions may reduce infectious morbidity. Finally, tumor stage and type do not necessarily increase the infectious morbidity of radical vulvar surgery. PMID:18475379

  4. Clinical Sensitivity and Specificity of Meconium Fatty Acid Ethyl Esters, Ethyl Glucuronide, and Ethyl Sulfate for Detecting Maternal Drinking During Pregnancy

    PubMed Central

    Himes, Sarah K.; Dukes, Kimberly A.; Tripp, Tara; Petersen, Julie M.; Raffo, Cheri; Burd, Larry; Odendaal, Hein; Elliott, Amy J.; Hereld, Dale; Signore, Caroline; Willinger, Marian; Huestis, Marilyn A.

    2015-01-01

    Background We investigated agreement between self-reported prenatal alcohol exposure (PAE) and objective meconium alcohol markers to determine the optimal meconium marker and threshold for identifying PAE. Methods Meconium fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) were quantified by liquid chromatography-tandem mass spectrometry in 0.1 g meconium from infants of Safe Passage Study participants. Detailed PAE information was collected from women with a validated timeline follow-back interview. As meconium formation begins during weeks 12-20, maternal self-reported drinking at or beyond 19 weeks was our exposure variable. Results Of 107 women, 33 reported no alcohol consumption in pregnancy, 16 stopped drinking by week 19, and 58 drank beyond 19 weeks (including 45 3rd trimester drinkers). There was moderate-substantial agreement between self-reported PAE ≥19 weeks and meconium EtG ≥30 ng/g (kappa: 0.57, 95% CI 0.41-0.73). This biomarker and associated cutoff was superior to a 7 FAEE sum ≥2 nmol/g and all other individual and combination marker cutoffs. With meconium EtG ≥30 ng/g as the gold-standard condition and maternal self-report ≥19 weeks gestation as the test condition, 82% sensitivity (95% CI: 71.6-92.0) and 75% specificity (95% CI: 63.2-86.8) were observed. A significant dose-concentration relationship between self-reported drinks per drinking day and meconium EtG ≥30 ng/g also was observed (P<0.01). Conclusions We assessed meconium EtG, EtS, and FAEE concentrations in the same meconium sample and compared concentrations to detailed self-reported PAE data. Maternal alcohol consumption ≥19 weeks was better represented by meconium EtG ≥30 ng/g compared to current FAEE cutoffs. PMID:25595440

  5. Optical on-line method of ethyl mercaptan detection in liquid phase in motor fuels

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2015-11-01

    The letter reports on the experimental research of the absorption spectra of ethyl mercaptan in liquid phase in various motor fuels (petrol, kerosene, and diesel fuel). The values of ethyl mercaptan absorption sections were obtained in the above-mentioned fuels in the spectral range of 280-475 nm, and the dependences of ethyl mercaptan absorption coefficients on its part in the analyzed mixture with motor fuels were researched. On the basis of the obtained results we propose an optical on-line method of ethyl mercaptan detection in motor fuels. The optimal spectral ranges for the highest sensitivity of ethyl mercaptan detection in various motor fuels were determined.

  6. Highly efficient palladium-catalyzed hydrostannation of ethyl ethynyl ether

    PubMed Central

    Andrews, Ian P.; Kwon, Ohyun

    2008-01-01

    The palladium-catalyzed hydrostannation of acetylenes is widely exploited in organic synthesis as a means of forming vinyl stannanes for use in palladium-catalyzed cross-coupling reactions. Application of this methodology to ethyl ethynyl ether results in an enol ether that is challenging to isolate from the crude reaction mixture because of incompatibility with typical silica gel chromatography. Reported here is a highly efficient procedure for the palladium-catalyzed hydrostannation of ethyl ethynyl ether using 0.1% palladium(0) catalyst and 1.0 equiv of tributyltin hydride. The product obtained is a mixture of regioisomers that can be carried forward with exclusive reaction of the β-isomer. This method is highly reproducible; relative to previously reported procedures, it is more economical and involves a more facile purification procedure. PMID:20011027

  7. Fragrance material review on 2-ethyl-1-hexanol.

    PubMed

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

    2010-07-01

    A summary of the safety data available for 2-ethyl-1-hexanol when used as a fragrance ingredient is presented. 2-Ethyl-1-hexanol is a member of the fragrance structural group branched chain saturated alcohols in which the common characteristic structural element is one hydroxyl group per molecule, and a C(4) to C(12) carbon chain with one or several methyl side chains. 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. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances. PMID:20659633

  8. Fragrance material review on 2-ethyl-1-butanol.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2010-07-01

    A toxicologic and dermatologic review of 2-ethyl-1-butanol when used as a fragrance ingredient is presented. 2-Ethyl-1-butanol is a member of the fragrance structural group branched chain saturated alcohols. The common characteristic structural elements of the alcohols with saturated branched chain are one hydroxyl group per molecule, and a C(4)-C(12) carbon chain with one or several methyl side chains. 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. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances. PMID:20659644

  9. Turbulent Motion in Ethyl Acetate-Water System

    NASA Astrophysics Data System (ADS)

    Ahmad, Jamil

    2000-09-01

    An overhead projector demonstration is described in which 4 mL of ethyl acetate is added to 10 mL of water contained in a 10-cm diameter Petri dish. Within a minute or so of the addition, image of a turbulent motion appears on the screen, at first at a few centers that eventually organize themselves in a line. The image of the line of turbulence is quite striking and resembles a moving front of dancing flames. The phenomenon arises because as ethyl acetate evaporates from the region where it has spread in the form of a monolayer, fresh material gets transferred to take its place. Because of the viscosity effects, this transfer of the surface film causes movement in the bulk of the material as well, making the process visible.

  10. Enantioselective hydrolysis of naproxen ethyl ester catalyzed by monoclonal antibodies.

    PubMed

    Shi, Zhen-Dan; Yang, Bing-Hui; Zhao, Jing-Jing; Wu, Yu-Lin; Ji, Yong-Yong; Yeh, Ming

    2002-07-01

    This report described that a hapten of racemic phosphonate 3 designed as the mimic of the transition state of hydrolysis of naproxen ethyl ester was successfully synthesized from easily available 2-acetyl-6-methoxy-naphthalene 5. Then BALB/C mice were immunized and one of the monoclonal catalytic antibodies, N116-27, which enantioselectively accelerated the hydrolysis of the R-(-)-naproxen ethyl ester was given. The Michaelis-Menton parameter for the catalyzed reaction was K(M)=6.67 mM and k(cat)/k(uncat)=5.8 x 10(4). This enantioselective result was explained by the fact that the R-isomer of rac-hapten was more immunogenic than the S-isomer. PMID:11983513

  11. SPECTROSCOPIC CHARACTERIZATION AND DETECTION OF ETHYL MERCAPTAN IN ORION

    SciTech Connect

    Kolesniková, L.; Alonso, J. L.; Daly, A. M.; Tercero, B.; Cernicharo, J.; Gordon, B. P.; Shipman, S. T. E-mail: jlalonso@qf.uva.es E-mail: terceromb@cab.inta-csic.es E-mail: brittany.gordon@ncf.edu

    2014-03-20

    New laboratory data of ethyl mercaptan, CH{sub 3}CH{sub 2}SH, in the millimeter- and submillimeter-wave domains (up to 880 GHz) provided very precise values of the spectroscopic constants that allowed the detection of gauche-CH{sub 3}CH{sub 2}SH toward Orion KL. This identification is supported by 77 unblended or slightly blended lines plus no missing transitions in the range 80-280 GHz. A detection of methyl mercaptan, CH{sub 3}SH, in the spectral survey of Orion KL is reported as well. Our column density results indicate that methyl mercaptan is ≅ 5 times more abundant than ethyl mercaptan in the hot core of Orion KL.

  12. Design, synthesis and characterization of neutral radical organic conductors: The spiro-bis (1,9-disubstituted phenalenyl) boron system

    NASA Astrophysics Data System (ADS)

    Chi, Xiaoliu

    2001-07-01

    Novel electronic devices (LED, FET, etc.) and room-temperature superconductivity are the most challenging fields in material science. Progress in these fields relies on the design and synthesis of new materials that have novel electronic properties in the solid state. Organic conductors and superconductors have focused on charge-transfer salts for more than 30 years. Although progress has been made, the transition temperatures of the majority of organic superconductors are far less than those of the ceramic-based superconductors. In 1975 Haddon predicted in a Nature article that neutral radicals, especially the phenalenyl system (PLY), could be used to make organic conductors and superconductors. Spiro-biphenalenyl boron radicals were proposed to be promising candidates in that they potentially form high-dimensional solids with a quarter-filled energy bands, which are thought to be important in stabilizing the metallic state. The synthesis of these radical crystals includes the preparation of various ligands and then their boron complexes, the purification of the precursors, the search for suitable reducing reagents and the crystallization of the radicals. Hexyl radical (27) is monomeric in the solid state, and shows Curie behavior throughout the temperature ranges 10--400 K. At room-temperature its conductivity sigma reaches 0.05 S/cm, the highest yet for a neutral organic molecular solid. Ethyl radical (23) has parallel PLY planes in the solid state, which form diamagnetic pi dimers below 150K, while butyl radical (25) forms a diamagnetic dimer at 340K. Surprisingly the conductivity increases sharply by two orders of magnitude at the transition to the dimerized state in both compounds. Interestingly, propyl radical (24) has a conductivity four orders of magnitude smaller than those of all other compounds mentioned. The location of the electrons in the radicals was studied. Several conductivity models were proposed based on the experimental results. By a careful

  13. [Detection and application of ethyl glucuronide in forensic toxicology].

    PubMed

    Zhao, Hui; Zhuo, Xian-yi; Shen, Bao-hua

    2009-02-01

    Ethyl glucuronide is a specific metabolite of ethanol. There have been plenty of articles referring its pharmacokinetics, detection and application as a specific bio-marker of alcohol intake. This article reviews various analytical methods of EtG, relationship between EtG quantification and ethanol intake, and criteria for determining chronic alcohol abuse, and origin of ethanol found in the cadavers by EtG analysis. EtG has its potential application in forensic toxicology. PMID:19397218

  14. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number of methyl groups and y is the number of ethyl groups. The average value of x is 0.3 and the average... the dry sample. (2) The viscosity of an aqueous solution, 2.5 grams of the material in 100...

  15. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number of methyl groups and y is the number of ethyl groups. The average value of x is 0.3 and the average... the dry sample. (2) The viscosity of an aqueous solution, 2.5 grams of the material in 100...

  16. Physiologically based pharmacokinetic modeling of ethyl acetate and ethanol in rodents and humans.

    PubMed

    Crowell, S R; Smith, J N; Creim, J A; Faber, W; Teeguarden, J G

    2015-10-01

    A physiologically based pharmacokinetic (PBPK) model was developed and applied to a metabolic series approach for the ethyl series (i.e., ethyl acetate, ethanol, acetaldehyde, and acetate). This approach bases toxicity information on dosimetry analyses for metabolically linked compounds using pharmacokinetic data for each compound and toxicity data for parent or individual compounds. In vivo pharmacokinetic studies of ethyl acetate and ethanol were conducted in rats following IV and inhalation exposure. Regardless of route, ethyl acetate was rapidly converted to ethanol. Blood concentrations of ethyl acetate and ethanol following both IV bolus and infusion suggested linear kinetics across blood concentrations from 0.1 to 10 mM ethyl acetate and 0.01-0.8 mM ethanol. Metabolic parameters were optimized and evaluated based on available pharmacokinetic data. The respiratory bioavailability of ethyl acetate and ethanol were estimated from closed chamber inhalation studies and measured ventilation rates. The resulting ethyl series model successfully reproduces blood ethyl acetate and ethanol kinetics following IV administration and inhalation exposure in rats, and blood ethanol kinetics following inhalation exposure to ethanol in humans. The extrapolated human model was used to derive human equivalent concentrations for the occupational setting of 257-2120 ppm ethyl acetate and 72-517 ppm ethyl acetate for continuous exposure, corresponding to rat LOAELs of 350 and 1500 ppm. PMID:26297692

  17. Electron attachment to fluorocarbon radicals

    NASA Astrophysics Data System (ADS)

    Shuman, Nicholas

    2014-10-01

    Most plasma environments contain populations of short-lived species such as radicals, the chemistry of which can have significant effects on the overall chemistry of the system. However, few experimental measurements of the kinetics of electron attachment to radicals exist due to the inherent difficulties of working with transient species. Calculations from first principles have been attempted, but are arduous and, because electron attachment is so sensitive to the specifics of the potential surface, their accuracy has not been established. Electron attachment to small fluorocarbon radicals is particularly important, as the data are needed for predictive modeling of plasma etching of semiconductor materials, a key process in the industrial fabrication of microelectronics. We have recently developed a novel flowing afterglow technique to measure several types of otherwise difficult to study plasma processes, including thermal electron attachment to radicals. Variable Electron and Neutral Density Attachment Mass Spectrometry (VENDAMS) exploits dissociative electron attachment in a weakly ionized plasma as a radical source. Here, we apply VENDAMS to a series of halofluorocarbon precursors in order to measure the kinetics of thermal electron attachment to fluorocarbon radicals. Results are presented for CF2, CF3, C2F5,C2F3,1-C3F7, 2-C3F7, and C3F5 from 300 K to 900 K. Both the magnitude and the temperature dependences of rate coefficients as well as product branching between associative and dissociative attachment are highly system specific; however, thermal attachment to all species is inefficient, never exceeding 5% of the collision rate. The data are analyzed using a recently developed kinetic modeling approach, which uses extended Vogt-Wannier theory as a starting point, accounts for dynamic effects such as coupling between the electron and nuclear motions through empirically validated functional forms, and finally uses statistical theory to determine the fate of

  18. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    PubMed

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters. PMID:26506263

  19. Radical Reactions of Alkyl 2-Bromo-2,2-difluoroacetates with Vinyl Ethers: "Omitted" Examples and Application for the Synthesis of 3,3-Difluoro-GABA.

    PubMed

    Kondratov, Ivan S; Bugera, Maksym Ya; Tolmachova, Nataliya A; Posternak, Ganna G; Daniliuc, Constantin G; Haufe, Günter

    2015-12-18

    Addition reactions of perfluoroalkyl radicals to ordinary or polyfluorinated alkenes have been frequently used to synthesize perfluoroalkylated organic compounds. Here ethyl/methyl 2-bromo-2,2-difluoroacetate, diethyl (bromodifluoromethyl)phosphonate, [(bromodifluoromethyl)sulfonyl]benzene, and ethyl 2-bromo-2-fluoroacetate were involved in Na2S2O4-mediated radical additions to vinyl ethers in the presence of alcohols to give difluoro or monofluoroacetyl-substituted acetals or corresponding difluoromethylphosphonate- and (difluoromethylphenyl)sulfonyl-substituted alkyl acetals. This methodology has also been applied as a key step in the synthesis of hitherto unknown 3,3-difluoro-GABA, completing the series of isomeric difluoro GABAs. Comparison of the pKa values of 3-fluoro- and 3,3-difluoro-GABA with that of the fluorine free parent compound showed that introduction of each fluorine lead to acidification of both the amino and the carboxyl functions by approximately one unit. PMID:26550962

  20. Sensory reception of the primer pheromone ethyl oleate

    NASA Astrophysics Data System (ADS)

    Muenz, Thomas S.; Maisonnasse, Alban; Plettner, Erika; Le Conte, Yves; Rössler, Wolfgang

    2012-05-01

    Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone—both were shown to influence onset of foraging—direct worker-worker interactions influence adult behavioral maturation. These interactions were narrowed down to the primer pheromone ethyl oleate, which is present at high concentrations in foragers, almost absent in young bees and was shown to delay the onset of foraging. Based on chemical analyses, physiological recordings from the antenna (electroantennograms) and the antennal lobe (calcium imaging), and behavioral assays (associative conditioning of the proboscis extension response), we present evidence that ethyl oleate is most abundant on the cuticle, received by olfactory receptors on the antenna, processed in glomeruli of the antennal lobe, and learned in olfactory centers of the brain. The results are highly suggestive that the primer pheromone ethyl oleate is transmitted and perceived between individuals via olfaction at close range.

  1. Fragrance material review on ethyl phenyl carbinyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of ethyl phenyl carbinyl acetate when used as a fragrance ingredient is presented. Ethyl phenyl carbinyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. 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 ethyl phenyl carbinyl acetate were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; and skin sensitization data. A safety assessment of the entire AAASAE 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 AAASAE in fragrances. PMID:22433983

  2. An organoselenium drug with antioxidant activity and free radical scavenging capacity in vitro.

    PubMed

    Ibrahim, Mohammad; Hassan, Waseem; Deobald, Anna Maria; Braga, Antonio Luis; Rocha, Joao B T

    2012-12-01

    Organoselenum compounds have been reported to have a wide range of pharmacological properties. Amine-based diselenide, (Z)-N-(4-methylbenzylidene)-1-(2-((2-(1-((E)-4-methyl benzylideneamino)ethyl)phenyl)diselanyl)phenyl)ethanamine ethyl)phenyl) diselanyl) phenyl) ethylimino) methyl)phenol (compound A), and diphenyl diselenide (PhSe)2 were screened for in vitro antioxidant activity. Compound A and (PhSe)2 were tested against sodium nitroprusside (SNP)- and Fe(II)-induced thiobarbituric acid-reactive species (TBARS) in rat brain homogenates. The radical scavenging activity was measured by 1,1-diphenyl-2-picrylhydrazyl assay. Both compounds A and (PhSe)2 decreased Fe(II)- and SNP-stimulated TBARS production in rat brain homogenates. Compound A exhibited the strongest antioxidant activity in the radical scavenging assay, although (PhSe)2, the simplest of the diaryl diselenide, presented no activity. In conclusion, the results of the present investigation indicated that compound A and (PhSe)2 had preventive effects against SNP- and Fe(II)-induced oxidative stress in rat brain homogenates. The amine group in the organic moiety dramatically changed the potency of amine-based diselenide. PMID:22562597

  3. A theoretical and experimental study of unimolecular and biomolecular radical hydrogen transfer reactions

    SciTech Connect

    Franz, J.A.; Autrey, T.; Gleicher, G.J.; Camaioni, D.M; Ferris, K.F.

    1991-04-01

    We have examined the intramolecular radical hydrogen transfer (RHT) reaction of the 2-(2-phenylethyl)cyclohexadienyl radical. Intramolecular hydrogen shift from the cyclohexadienyl ring to the ipso position of the phenyl ring, followed by {beta}-scission would have given benzene and ethylbenzene as products. Competing with this reaction is {beta}-scission to give benzyl radical and isotoluene, or hydrogen loss to give bibenzyl. Studies to date suggest a barrier for thermoneutral hydrogen transfer in the RHT reaction between aromatic systems of ca. 18 kcal/mole. None of the studies of RHT or equivalent mechanisms have attempted to directly observe H{sub 2}, and direct determination of Arrhenius parameters and a detailed examination of the pathway of the hydrogen transfer process remains to be carried out. To better understand the structural and energetic aspects of RHT, we have carried out a semiempirical molecular orbital study of bimolecular and intramolecular RHT reactions for a variety of aromatic systems. We also examined in detail the energetics of hydrogen transfer between ethyl radical and ethylene via RHT, an addition/metathesis/scission pathway, and a hybrid concerted'' pathway. 11 refs., 1 fig., 4 tabs.

  4. Absolute rate constants of alkoxyl radical reactions in aqueous solution. [Tert-butyl hydroperoxide

    SciTech Connect

    Erben-Russ, M.; Michel, C.; Bors, W.; Saran, M.

    1987-04-23

    The pulse radiolysis technique was used to generate the alkoxyl radical derived from tert-butyl hydroperoxide (/sup t/BuOOH) in aqueous solution. The reactions of this radical with 2,2'-azinobis(3-ethyl-6-benzothiazolinesulfonate) (ABTS) and promethazine were monitored by kinetic spectroscopy. The unimolecular decay rate constant of the tert-butoxyl radical (/sup t/BuO) was determined to be 1.4 x 10/sup 6/ s/sup -1/. On the basis of this value, the rate constants for /sup t/BuO attack on quercetin, crocin, crocetin, ascorbate, isoascorbate, trolox c, glutathione, thymidine, adenosine, guanosine, and unsaturated fatty acids were determined. In addition, the reaction of /sup t/BuO with the polyunsaturated fatty acids (PUFA) was observed by directly monitoring the formation of the fatty acid pentadienyl radicals. Interestingly, the attack of /sup t/BuO on PUFA was found to be faster by about one order of magnitude as compared to the same reaction in a nonpolar solvent.

  5. Radical Puppets and the Language of Art

    ERIC Educational Resources Information Center

    Asher, Rikki

    2009-01-01

    Radical puppets are puppets with a social message. Radical puppets encourage creative ideas that lead toward understanding global and environmental aspects of society through the "art of the puppet," a phrase coined by American puppeteer Bill Baird (1965). There is a blending of performance and visual art in puppetry. Through radical puppetry,…

  6. Free-radical chemistry of sulfite.

    PubMed Central

    Neta, P; Huie, R E

    1985-01-01

    The free-radical chemistry of sulfite oxidation is reviewed. Chemical transformations of organic and biological molecules induced by sulfite oxidation are summarized. The kinetics of the free-radical oxidations of sulfite are discussed, as are the kinetics of the reactions of the sulfite-derived radicals SO3 and the peroxy derivative SO5 with organic compounds. PMID:3830699

  7. [Erectile rehabilitation after radical prostatectomy].

    PubMed

    Droupy, S; Giuliano, F; Costa, P

    2009-12-01

    The concept of penile rehabilitation involves the procedures designed to improve oxygen delivery the penile erectile tissue to minimized tissue damage during the period of neural recovery following radical prostatectomy. Many basic research studies support the rationale and mechanism of the concept of penile rehabilitation, however they are few clinical studies in the literature that provide a clear medical evidence of its efficacy in patients. Waiting for new data, it is recommended to propose to the patients, following a radical prostatectomy, an active pharmacological penile rehabilitation. This rehabilitation involves counselling with the couple to have regular sexual activities, ideally 1 to 3 times a week. Penile erections could be induced by intracavernosal injections of PGE1 or improved by using PDE5 inhibitors on demand. The results of daily use of PDE5 inhibitor are conflicting and then it cannot be recommended systematically waiting for new data. The rehabilitation could be maintained for about 2 years as results improve with time. PMID:20123519

  8. Mutagenicity of Oxygen Free Radicals

    NASA Astrophysics Data System (ADS)

    Moody, Carmella S.; Hassan, Hosni M.

    1982-05-01

    Paraquat 1,1'-dimethyl-4,4'-bipyridinium dichloride) was used as an intracellular generator of oxygen free radicals and was found to be highly mutagenic for Salmonella typhimurium. It caused both base-pair substitution and frameshift mutations. Paraquat was much more toxic and mutagenic in a simple nutritionally restricted medium than in a rich complex medium. The mutagenicity of paraquat was dependent upon the presence of a supply of both electrons and oxygen. Cells containing high levels of superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) were more resistant to the toxicity and the mutagenicity of paraquat than were cells containing normal levels of this enzyme. The mutagenicity of paraquat thus appears to be due to its ability to exacerbate the intracellular production of superoxide radicals.

  9. Comparison of ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) concentrations in hair for testing abstinence.

    PubMed

    Albermann, M E; Musshoff, F; Madea, B

    2011-04-01

    Hair analysis is a powerful tool for retrospective drug analysis. By determining the minor ethanol metabolites ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) in hair, even a previous consumption of alcohol is detectable. However, previous studies showed a lack of correlation if both parameters are determined simultaneously. A further study was conducted to confirm or refute these results. One hundred and sixty hair samples were analyzed for EtG and FAEE in the context of driving ability. In 109 cases, alcohol abstinence was clearly proven and was excluded in 15 cases. In 36 cases, ambiguous results were found. Possible reasons for the deviating results are discussed. It is recommended, that in context of driving ability diagnostics the EtG result is determinant. In critical cases FAEE concentrations can be determined for checking purposes, but a negative FAEE result cannot refute a determined EtG concentration >7 pg/mg. PMID:21127843

  10. Liquid-liquid extraction separation of iron (III) with 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester.

    PubMed

    Jayachandran, J; Dhadke, P M

    1997-07-01

    Liquid-liquid extraction separation of iron(III) with 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester (PC-88A) in toluene has been studied. Quantitative extraction of iron(III) with 5 x 10(-3) M PC-88A in toluene is observed in the pH range 0.75-2.5. From the extracted complex species in the organic phase iron(III) was stripped with 1-4 M HNO(3), 1.5-4 M H(2)SO(4) and 1.5-4 M HCl, and later determined spectrophotometrically by thiocyanate method. Separation of iron(III) was carried out with some of the first transition metals in binary and multicomponent mixtures. This method was extended for the determination of iron in real samples. PMID:18966864

  11. In vitro α-glucosidase inhibition, antioxidant, anticancer, and antimycobacterial properties of ethyl acetate extract of Aegle tamilnadensis Abdul Kader (Rutaceae) leaf.

    PubMed

    R, Pratap Chandran; S, Nishanth Kumar; S, Manju; S, Abdul Kader; B S, Dileep Kumar

    2015-01-01

    The present study was aimed to investigate in vitro α-glucosidase inhibition, antioxidant, anticancer, and antimycobacterial activities of the ethyl acetate extract of A. tamilnadensis leaves. The extract recorded strong α-glucosidase inhibition with an IC50 value of 100 μg/ml. The antioxidant potential of the extract was evaluated by nitric oxide radical inhibition, lipid peroxidation inhibition, ferric thiocyanate, and ABTS radical scavenging assay, and the extract recorded significant antioxidant activity. The ferric thiocyanate activity of extract was superior to butylated hydroxyl anisol (BHA), the standard antioxidant agent. The anticancer activity of the extract was evaluated against (1) breast cancer cell lines (MDAM B-231), (2) cervical cancer cell lines (HeLa), and (3) lung cancer cell line (A 549) using MTT assay, and significant activity was recorded against A 549 with an IC50 value of 64 μg/ml. Further studies on the morphology, acridine orange/ethidium bromide staining, and cell cycle analysis by flow cytometry confirm the extract-induced apoptosis in A 549. This extract also recorded significant anti-tuberculosis activity against Mycobacterium smegmatis. The current study suggests that the ethyl acetate extract of A. tamilnadensis is a potential source of natural α-glucosidase inhibitor and antioxidant for protection as well as prevention of life-threatening diseases like cancer. PMID:25380641

  12. Geoscientists and the Radical Middle

    NASA Astrophysics Data System (ADS)

    Tinker, S. W.

    2015-12-01

    Addressing the great challenges facing society requires industry, government, and academia to work together. I call this overlap space, where compromises are made and real solutions determined, the Radical Middle. Radical because it can appear at times as if the loudest and most publicly influential voices lie outside of the actual solution space, content to provoke but not problem-solve. One key area where geoscientists can play a lead role in the Radical Middle is in the overlap between energy, the environment, and the economy. Globally, fossil fuels still represent 85% of the aggregate energy mix. As existing conventional oil and natural-gas reservoir production continues to slowly decline, unconventional reservoirs, led today by shale and other more expensive resources, will represent a growing part of the oil and gas production mix. Many of these unconventional reservoirs require hydraulic fracturing. The positive economic impact of hydraulic fracturing and associated natural gas and oil production on the United States economy is well documented and undeniable. Yet there are environmental concerns about fracking, and some states and nations have imposed moratoria. This energy-environment-economy space is ideal for leadership from the geosciences. Another such overlap space is the potential for geoscience leadership in relations with China, whose economy and global presence continue to expand. Although China is building major hydropower and natural-gas power plants, as well as nuclear reactors, coal is still king—with the associated environmental impacts. Carbon sequestration—onshore in brine and to enhance oil recovery, as well as offshore—could prove viable. It is vital that educated and objective geoscientists from industry, government, and academia leave their corners and work together in the Radical Middle to educate the public and develop and deliver balanced, economically sensible energy and environmental strategies.

  13. Radical Smiles Rearrangement: An Update.

    PubMed

    Allart-Simon, Ingrid; Gérard, Stéphane; Sapi, Janos

    2016-01-01

    Over the decades the Smiles rearrangement and its variants have become essential synthetic tools in modern synthetic organic chemistry. In this mini-review we summarized some very recent results of the radical version of these rearrangements. The selected examples illustrate the synthetic power of this approach, especially if it is incorporated into a domino process, for the preparation of polyfunctionalized complex molecules. PMID:27399654

  14. Hydroxyl radical detection in vivo

    SciTech Connect

    Chevion, M.; Floyd, R.A.

    1986-05-01

    Hydroxyl radicals have been implicated as the actual species responsible for the deleterious effects of active oxygen in biology. However, in most cases, its presence has only been inferred by circumstantial evidence. Using electrochemical detection coupled to HPLC separation technique the authors can identify and quantitate (at sub-picomole level) the hydroxylated products of 3 aromatic compounds (phenol, salicylate, and 2-deoxy-guanosine) as a direct measure of hydroxyl radical formation. Firstly, the authors showed that mixing ascorbate with copper ions (in the absence of presence of a protein) yields catechols, dihydroxybenzoic acids and 8-OH-deoxy-guanosine (8-OHdG). This approach has been used to study the formation of OH in vivo. Human granulocytes stimulated with TPA showed that 8-OHdG was formed in the cellular DNA at high levels (one 8-OHdG/800 DNA bases). Unstimulated granulocytes contained 8-OHdG below detection level. Formation of 8-OHdG in the TPA-stimulated granulocytes DNA was decreased by the addition of SOD and catalase. Using salicylate as an in vivo scavenger of hydroxyl radicals the authors showed that the level of trapped-dihydroxybenzoic acids is increased approx.8 and approx.3 fold in the lungs and liver of paraquat-poisoned mice, respectively, as compared to normal animals. Similarly, the detected level of dihydroxybenzoic acids in the hearts of adriamycin-treated rats was increased over 100-fold as compared to the hearts of control animals.

  15. A radical way to burn

    SciTech Connect

    Ashley, S.

    1996-08-01

    By manipulating chamber geometries as well as engine cycle pressures and timing, engineers are exploiting a long-obscure technology known as activated radical combustion. Piston-driven internal combustion engines generally come in two varieties: compression-ignited diesels and spark-ignited gasoline power plants. There, is however, a third way to initiate burning of the fuel-air mixture. The technique--variously called radical ignition (RI), activated radical (AR) combustion, Toyota-Soken combustion, and active thermo-atmosphere combustion--is not exactly new, but only recently have engineers begun to exploit the process in practical power plants. These new units include a lightweight two-stroke racing-motorcycle engine, truck diesels with reduced soot output, and lean-burn spark-ignited car engines. This long-obscure combustion process is based on a range of specialized chemical kinetic and physical acoustic techniques developed over decades. Engineers manipulate fundamental combustion parameter such as chamber geometries, valving and porting configurations, and engine cycle pressures and timing to foster the formation of certain highly reactive chemical species that lower the fuel-air mixture`s flash point so that even modest compression make sit self-ignite. These chemical initiators are then retained into the next cycle to start combustion, allowing the engineer to run stably with no spark.

  16. Radical scavengers from heavy hydrocarbons

    SciTech Connect

    Kubo, Junichi

    1996-10-01

    The hydrogen-donating properties of some hydrocarbons form the basis for processes such as coal liquefaction and heavy oil upgrading. However, these hydrocarbons have seldom been used for other purposes, because their potential applications have not been well recognized. Research has indicated that these hydrogen-donating hydrocarbons can be used in important reactions as radical scavengers and have properties particular to those of pure hydrocarbons without functional groups containing heteroatoms. Over years of study researchers have found that pure hydrocarbons with radical-scavenging effects nearly as high as those in conventional hindered phenolic antioxidants can be produced from petroleum, and these hydrogen-donating hydrocarbons exhibit such effects even in oxidative atmospheres (i.e., they function as antioxidants). He has also shown that these mixtures have some properties particular to pure hydrocarbons without functional groups containing heteroatoms, and they`ve seen that a mechanism based on the steric effects appears when these hydrocarbons are used in heavy oil hydroprocessing. Hydrogen-donating hydrocarbons should be a viable resource in many applications. In this article, he presents radical-scavenging abilities, characteristics as pure hydrocarbons, and applications on the basis of the studies.

  17. pH-dependent one- and two-electron oxidation of 3,5-dicarbethoxy-2,6-dimethyl-4-ethyl-1,4-dihydropyridine catalyzed by horseradish peroxidase.

    PubMed

    Sugiyama, K; Correia, M A; Thummel, K E; Nagata, K; Darbyshire, J F; Osawa, Y; Gillette, J R

    1994-01-01

    The porphyrinogenic agent 3,5-dicarbethoxy-2,6-dimethyl-4-ethyl-1,4-dihydropyridine (DDEP) is known to inactivate hepatic cytochrome P450 (P450) enzymes 2C11, 2C6, and 3A1 [Correia et al. (1987) Arch. Biochem. Biophys. 258, 436-451] by different mechanisms. The inactivation of P450 2C11 and 2C6 appears to be due to the ethylation of the heme in the active sites of the enzymes [Augusto et al. (1982) J. Biol. Chem. 257, 11288-11295], whereas the inactivation of P450 3A1 appears to involve the covalent binding of the heme to the apoprotein [Correia et al. (1987)]. Moreover, we have found that DDEP inactivates horseradish peroxidase (HRP) pretreated with hydrogen peroxide. In this system, DDEP was oxidized predominately to 3,5-dicarbethoxy-2,6-dimethyl-4-ethylpyridine (EDP) under weakly acidic conditions and predominately to 3,5-dicarbethoxy-2,6-dimethylpyridine (DP) under basic conditions. The loss of heme and the formation of altered heme products were also pH-dependent and were correlated with the formation of DP and the inactivation of HRP. Thus the inactivation of HRP appears to depend on the formation of an ethyl radical, which presumably reacts with the heme in the active site of the enzyme. Similar product ratios were obtained for the oxidation of DDEP by K3Fe(CN)6, indicating that product ratios of DP over EDP are mainly determined by the pH of buffer. These results, in addition to semiemperical calculations (AM1) for the oxidation of DDEP in the gas phase, are consistent with the idea that the inhibitor undergoes a single-electron oxidation to form the DDEP radical cation, the fate of which depends on the environment of the active site of the enzyme. The proposed formation of a radical cation by the abstraction of an electron from nitrogen is consistent with the finding of low intramolecular isotope effects of the metabolism of 3,5-dicarbethoxy-2,6-dimethyl-[4-2H,4-1H]-1,4-dihydropyridine by P450 2C11 and 3A4. Under basic or aprotic conditions, the radical

  18. 40 CFR 180.483 - O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false O- O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances for residues. 180.483 Section 180.483 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.483...

  19. GENOTOXICITY OF ACRYLIC ACID, METHYL ACRYLATE, ETHYL ACRYLATE, METHYL METHACRYLATE, AND ETHYL METHACRYLATE IN L5178Y MOUSE LYMPHOMA CELLS (JOURNAL VERSION)

    EPA Science Inventory

    A series of monomeric acrylate/methacrylate esters (methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate) as well as acrylic acid were examined for genotoxic activity in L5178Y mouse lymphoma cells without exogenous activation. All five compounds induced c...

  20. Protective Effect of the Ethyl Acetate Fraction of Sargassum muticum Against Ultraviolet B–Irradiated Damage in Human Keratinocytes

    PubMed Central

    Piao, Mei Jing; Yoon, Weon Jong; Kang, Hee Kyoung; Yoo, Eun Sook; Koh, Young Sang; Kim, Dong Sam; Lee, Nam Ho; Hyun, Jin Won

    2011-01-01

    The aim of this study was to investigate the cytoprotective properties of the ethyl acetate fraction of Sargassum muticum (SME) against ultraviolet B (UVB)-induced cell damage in human keratinocytes (HaCaT cells). SME exhibited scavenging activity toward the 1,1-diphenyl-2-picrylhydrazyl radicals and hydrogen peroxide (H2O2) and UVB-induced intracellular reactive oxygen species (ROS). SME also scavenged the hydroxyl radicals generated by the Fenton reaction (FeSO4 + H2O2), which was detected using electron spin resonance spectrometry. In addition, SME decreased the level of lipid peroxidation that was increased by UVB radiation, and restored the level of protein expression and the activities of antioxidant enzymes that were decreased by UVB radiation. Furthermore, SME reduced UVB-induced apoptosis as shown by decreased DNA fragmentation and numbers of apoptotic bodies. These results suggest that SME protects human keratinocytes against UVB-induced oxidative stress by enhancing antioxidant activity in cells, thereby inhibiting apoptosis. PMID:22174656

  1. Free-radical-mediated DNA binding.

    PubMed Central

    O'Brien, P J

    1985-01-01

    Free-radical metabolites can be generated metabolically by a one-electron reductase-catalyzed reaction or a "peroxidase" catalyzed oxidation or by photoactivation of a wide variety of aromatic xenobiotics. Radicals may also be generated during lipid peroxidation. Some radicals can react with DNA or bind covalently or noncovalently as a dismutation product or as a dimer, trimer or polymeric product. Modification to the DNA can result in single-strand breaks, loss of template activity, and crosslinking. The binding can prevent enzymic digestion. In some cases, the radicals react with oxygen, resulting before conversion to DNA reactive oxygen species. Most radicals probably do not interact with DNA. PMID:3007090

  2. Preventive efficacy of hydroalcoholic extract of Cymbopogon citratus against radiation-induced DNA damage on V79 cells and free radical scavenging ability against radicals generated in vitro.

    PubMed

    Rao, B S S; Shanbhoge, R; Rao, B N; Adiga, S K; Upadhya, D; Aithal, B K; Kumar, M R S

    2009-04-01

    This study presents the findings of free radical scavenging and antigenotoxic effect of hydroalcoholic extract of Cymbopogon citratus (CCE). The CCE at a concentration of 60 microg/mL resulted in a significant scavenging ability of 2,2-diphenyl-2-picryl hydrazyl (DPPH; (85%), 2,2-azinobis (3-ethyl benzothiazoline-6-sulphonic acid) (ABTS; 77%), hydroxyl (70%), superoxide (76%), nitric oxide (78%) free radicals generated using in vitro and also a moderate anti-lipid peroxidative effect (57%). Further, the radiation-induced antigenotoxic potential of CCE was assessed in Chinese hamster lung fibroblast cells (V79) using micronucleus assay. The CCE resulted in a dose-dependent decrease in the yield of radiation-induced micronuclei, with a maximum effect at 125 microg/mL CCE for 1 h before 2 Gy of radiation. Similarly, there was a significant (P < 0.05-0.0001) decrease in percentage of micronuclei when V79 cells were treated with optimal dose of CCE (125 microg/mL) before exposure to different doses of gamma radiation, that is, 0.5-4 Gy, compared with radiation alone groups. The results of the micronucleus study indicated antigenotoxic effect demonstrating the radioprotective potential of CCE and, which may partly due to its and antioxidant capacity as it presented its ability to scavenge various free radicals in vitro and anti-lipid peroxidative potential. PMID:19734270

  3. Gas chromatography-mass spectrometry of ethyl palmitate calibration and resolution with ethyl oleate as biomarker ethanol sub acute in urine application study

    NASA Astrophysics Data System (ADS)

    Suaniti, Ni Made; Manurung, Manuntun

    2016-03-01

    Gas Chromatography-Mass Spectrometry is used to separate two and more compounds and identify fragment ion specific of biomarker ethanol such as palmitic acid ethyl ester (PAEE), as one of the fatty acid ethyl esters as early detection through conyugated reaction. This study aims to calibrate ethyl palmitate and develop analysis with oleate acid. This methode can be used analysis ethanol and its chemistry biomarker in ethanol sub-acute consumption as analytical forensic toxicology. The result show that ethanol level in urine rats Wistar were 9.21 and decreased 6.59 ppm after 48 hours consumption. Calibration curve of ethyl palmitate was y = 0.2035 x + 1.0465 and R2 = 0.9886. Resolution between ethyl palmitate and oleate were >1.5 as good separation with fragment ion specific was 88 and the retention time was 18 minutes.

  4. Labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine in hepatic RNA of mice given[ethyl-1,2(-3)H or ethyl-1(-14)C]ethyl carbamate (urethan).

    PubMed

    Ribovich, M L; Miller, J A; Miller, E C; Timmins, L G

    1982-01-01

    Injection of a single dose of[ethyl-1,2(-3)H]or[ethyl-1(-14C]- ethyl carbamate into 12-day old male[C57BL/6 x C3H/He]F1 mice or of[ethyl-1,2(-3H]ethyl carbamate into adult male A/Jax mice resulted in the formation of labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine adducts in the hepatic RNA. These adducts were characterized by comigration on h.p.l.c. of 3H or 14C in enzymatic hydrolysates of the RNA with synthetic standards. Both the ethenoadenosine and ethenocytidine were further characterized by their conversion to acetylated products that comigrated with acetylated synthetic standards. The ethenoadenosine was also converted by anhydrous trifluoroacetic acid to a product that comigrated with synthetic 1,N6-ethenoadenine. The levels of adducts in the hepatic RNA 12 h after a single injection of 0.5-0.6 mg of ethyl carbamate/g body weight were 6-10 and 2-3 pmol/mg RNA of ethenoadenosine and ethenocytidine, respectively. No labeled ethenoadenosine or ethenocytidine could be detected in the hepatic RNA of mice given[1-14C]ethanol, an enzymatic hydrolysis product of ethyl carbamate. These data indicate that ethyl carbamate may be metabolically activated by dehydrogenation to vinyl carbamate and subsequent epoxidation of the latter compound as previously proposed. Vinyl carbamate epoxide may form etheno derivatives in a manner analogous to that demonstrated for chloroethylene oxide, an electrophilic metabolite of vinyl chloride. Vinyl carbamate has been shown to have the same spectrum of tumor induction as ethyl carbamate but to be much more active than the latter carcinogen. PMID:6178529

  5. Extracts and constituents of Rubus chingii with 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity.

    PubMed

    Ding, Hsiou-Yu

    2011-01-01

    The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC(50) values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC(50) values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time. PMID:21747716

  6. Thermal Decomposition of Ethyl Formate behind the Reflected Shock Waves in the Temperature Range of 909-1258K

    NASA Astrophysics Data System (ADS)

    Balaganesh, M.; Sudhakar, G.; Rajakumar, B.

    Ethyl formate is the simplest model of ethyl esters which are considered as biodiesel. Systematic tests on properties and reactivity of biodiesel have been reported[1, 2]. Methyl and ethyl ester mix can offer improved physical properties. Generally, ethyl esters are slightly more reactive than the methyl esters[3]. Also ethyl formate is an interstellar molecule. It was first detected in interstellar space by Belloche et al.[4]. So studies of this molecule are required to understand the fuel properties and interstellar chemistry.

  7. Free radicals and activated oxygen.

    PubMed

    Famaey, J P

    1982-01-01

    Superoxide anion (0(-2)), hydrogen peroxide (H2O2) and hydroxyl radical (OH.) are products of the biological reduction of 0(2). They are very reactive and poorly tolerated within living systems and enzymes that catalytically scavenge these products have been evolved as defense mechanisms. These include superoxide dismutases (SOD), catalase and peroxidases. Large amounts of O-2 are produced by different enzymatic and non enzymatic biological processes. Large amounts of activated oxygens are produced by phagocytosing cells such as macrophages and polymorphonuclear cells. This production is associated with the bactericidal actions of these cells but it also largely contributes to exacerbate and sustain the inflammation where these cells congregate. The arachidonic acid pathway triggered by the inflammatory stimuli is also a source for these oxidizing radicals. The production of activated oxygens has been associated with the normal aging process but also with various toxic reactions (e.g. the toxicity of the herbicide paraquat, of the ionizing radiations, of certain antibiotics such as streptonigrin, etc. . . .). O-2 induces the depolymerization of hyaluronic acid which lends viscosity and lubricating properties to synovial fluids. SOD possess antiinflammatory properties and a bovine SOD, orgotein, has now been largely investigated by intramuscular and intraarticular injections in the treatment of rheumatic diseases. Various antiinflammatory compounds (e.g. the salicylates) are able either to inhibit the production of these oxygen radicals or to scavenge them which seems of importance for their antiinflammatory properties. Singlet oxygen, another activated oxygen, might also play a role in the inflammatory process. PMID:6295769

  8. Influence of Gilbert's syndrome on the formation of ethyl glucuronide.

    PubMed

    Huppertz, Laura M; Gunsilius, Leonie; Lardi, Christelle; Weinmann, Wolfgang; Thierauf-Emberger, Annette

    2015-09-01

    A drinking experiment with participants suffering from Gilbert's syndrome was performed to study the possible influence of this glucuronidation disorder on the formation of ethyl glucuronide (EtG). Gilbert's syndrome is a rather common and, in most cases, asymptomatic congenital metabolic aberration with a prevalence of about 5 %. It is characterized by a reduction of the enzyme activity of the uridine diphosphate glucuronosyltransferase (UGT) isoform 1A1 up to 80 %. One of the glucuronidation products is EtG, which is formed in the organism following exposure to ethanol. EtG is used as a short-term marker for ethyl alcohol consumption to prove abstinence in various settings. After 2 days of abstinence from ethanol and giving a void urine sample, 30 study participants drank 0.1 L of sparkling wine (9 g ethanol). 3, 6, 12, and 24 h after drinking, urine samples were collected. 3 hours after drinking, an additional blood sample was taken, in which liver enzyme activities, ethanol, hematological parameters, and bilirubin were measured. EtG and ethyl sulfate (EtS), another short-term marker of ethanol consumption, were determined in the urine samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS); creatinine was measured photometrically. In all participants, EtG and EtS were detected in concentrations showing a wide range (EtG: 3 h sample 0.5-18.43 mg/L and 6 h sample 0.67-13.8 mg/L; EtS: 3 h sample 0.87-6.87 mg/L and 6 h sample 0.29-4.48 mg/L). No evidence of impaired EtG formation was found. Thus, EtG seems to be a suitable marker for ethanol consumption even in individuals with Gilbert's syndrome. PMID:25680552

  9. Atmospheric chemistry of methyl and ethyl N,N,N',N'-tetramethylphosphorodiamidate and O,S-dimethyl methylphosphonothioate.

    PubMed

    Aschmann, Sara M; Atkinson, Roger

    2013-10-31

    Rate constants for the reactions of OH radicals with methyl N,N,N',N'-tetramethylphosphorodiamidate [CH3OP(O)[N(CH3)2]2; MTMPDA], ethyl N,N,N',N'-tetramethylphosphorodiamidate [C2H5OP(O)[N(CH3)2]2; ETMPDA], and O,S-dimethyl methylphosphonothioate [CH3OP(O)(CH3)SCH3; OSDMMP] have been measured over the temperature range 281-349 K at atmospheric pressure of air using a relative rate method. The rate expressions obtained were 4.96 × 10(-12) e((1058±71)/T) cm(3) molecule(-1) s(-1) (1.73 × 10(-10) cm(3) molecule(-1) s(-1) at 298 K) for OH + MTMPDA, 4.46 × 10(-12) e((1144±95)/T) cm(3) molecule(-1) s(-1) (2.07 × 10(-10) cm(3) molecule(-1) s(-1) at 298 K) for OH + ETMPDA, and 1.31 × 10(-13) e((1370±229)/T) cm(3) molecule(-1) s(-1) (1.30 × 10(-11) cm(3) molecule(-1) s(-1) at 298 K) for OH + OSDMMP. The rate constant for OH + OSDMMP was independent of O2 content over the range 2.1-71% O2 at 296 ± 2 K. In addition, rate constants for the reactions of NO3 radicals and O3 with MTMPDA, of (1.4 ± 0.1) × 10(-12) cm(3) molecule(-1) s(-1) and <3.5 × 10(-19) cm(3) molecule(-1) s(-1), respectively, were measured at 297 ± 2 K. Products of the OH radical- and, for MTMPDA, NO3 radical-initiated reactions were investigated using gas chromatography and in situ atmospheric pressure ionization mass spectrometry. A product of molecular weight 180 was observed from the OH and NO3 radical-initiated reactions of MTMPDA, and this is attributed to CH3OP(O)[N(CH3)2]N(CH3)CHO. Similarly, a product of molecular weight 194 was observed from the OH + ETMPDA reaction and attributed to C2H5OP(O)[N(CH3)2]N(CH3)CHO. Possible reaction mechanisms are discussed. PMID:24134801

  10. Aromatic-radical oxidation chemistry

    SciTech Connect

    Glassman, I.; Brezinsky, K.

    1993-12-01

    The research effort has focussed on discovering an explanation for the anomalously high CO{sub 2} concentrations observed early in the reaction sequence of the oxidation of cyclopentadiene. To explain this observation, a number of plausible mechanisms have been developed which now await experimental verification. One experimental technique for verifying mechanisms is to probe the reacting system by perturbing the radical concentrations. Two forms of chemical perturbation of the oxidation of cyclopentadiene were begun during this past year--the addition of NO{sub 2} and CO to the reacting mixture.

  11. Laser spectroscopy of hydrocarbon radicals

    SciTech Connect

    Chen, P.

    1993-12-01

    The author reports the application of supersonic jet flash pyrolysis to the specific preparation of a range of organic radicals, biradicals, and carbenes in a skimmed molecular beam. Each species was produced cleanly and specifically, with little or no secondary reactions by the thermal dissociation of appropriately designed and synthesized organic precursors. Photoelectron spectra of the three isomeric C{sub 3}H{sub 2} carbenes, ortho-benzyne, and the {alpha},3-dehydrotoluene biradical, were used to establish adiabatic ionization potentials for use in thermochemical determinations.

  12. Iron and iron derived radicals

    SciTech Connect

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  13. Micellar phase boundaries under the influence of ethyl alcohol.

    PubMed

    Bergeron, Denis E

    2016-03-01

    The Compton spectrum quenching technique is used to monitor the effect of ethyl alcohol (EtOH) additions on phase boundaries in two systems. In toluenic solutions of the nonionic surfactant, Triton X-100, EtOH shifts the boundary separating the first clear phase from the first turbid phase to higher water:surfactant ratios. In a commonly used scintillant, Ultima Gold AB, the critical micelle concentration is not shifted. The molecular interactions behind the observations and implications for liquid scintillation counting are discussed. PMID:26585642

  14. Ethyl alcohol boiling heat transfer on multilayer meshed surfaces

    NASA Astrophysics Data System (ADS)

    Dåbek, Lidia; Kapjor, Andrej; Orman, Łukasz J.

    2016-06-01

    The paper presents the problem of heat transfer enhancement with the application of multilayer metal mesh structures during boiling of ethyl alcohol at ambient pressure. The preparation of samples involved sintering fine copper meshes with the copper base in the reduction atmosphere in order to prevent oxidation of the samples. The experiments included testing up to 4 layers of copper meshes. Significant augmentation of boiling heat transfer is possible, however, considerable number of meshes actually hinders heat transfer conditions and leads to the reduction in the heat flux transferred from the heater surface.

  15. Photoelectron spectroscopic study of the ethyl cyanoacrylate anion

    NASA Astrophysics Data System (ADS)

    Zhang, Xinxing; Tang, Xin; Bowen, Kit

    2013-09-01

    Anion photoelectron spectroscopy and density functional theory have been utilized to study the parent, ethyl cyanoacrylate molecular anion, ECA-. The measured electron affinity (0.9 ± 0.2 eV), vertical detachment energy (1.3 ± 0.1 eV), and anion-to-triplet neutral, photodetachment transition energies (4.0 ± 0.1 eV and 4.5 ± 0.1 eV) all compare well with their calculated values. The relatively high electron affinity of the ECA monomer is responsible for the fact that its “anionic” polymerization mechanism proceeds even with weak nucleophiles, such as water.

  16. Ethyl Pyruvate Combats Human Leukemia Cells but Spares Normal Blood Cells.

    PubMed

    Birkenmeier, Gerd; Hemdan, Nasr Y A; Kurz, Susanne; Bigl, Marina; Pieroh, Philipp; Debebe, Tewodros; Buchold, Martin; Thieme, Rene; Wichmann, Gunnar; Dehghani, Faramarz

    2016-01-01

    Ethyl pyruvate, a known ROS scavenger and anti-inflammatory drug was found to combat leukemia cells. Tumor cell killing was achieved by concerted action of necrosis/apoptosis induction, ATP depletion, and inhibition of glycolytic and para-glycolytic enzymes. Ethyl lactate was less harmful to leukemia cells but was found to arrest cell cycle in the G0/G1 phase. Both, ethyl pyruvate and ethyl lactate were identified as new inhibitors of GSK-3β. Despite the strong effect of ethyl pyruvate on leukemia cells, human cognate blood cells were only marginally affected. The data were compiled by immune blotting, flow cytometry, enzyme activity assay and gene array analysis. Our results inform new mechanisms of ethyl pyruvate-induced cell death, offering thereby a new treatment regime with a high therapeutic window for leukemic tumors. PMID:27579985

  17. Dimeric phenalenyl-based neutral radical molecular conductors.

    PubMed

    Chi, X; Itkis, M E; Kirschbaum, K; Pinkerton, A A; Oakley, R T; Cordes, A W; Haddon, R C

    2001-05-01

    We report the preparation, crystallization, and solid-state characterization of ethyl (3)- and butyl (4)-substituted spiro-biphenalenyl radicals. Both of these compounds are found to be conducting face-to-face pi-dimers in the solid state but with different room-temperature magnetic ground states. At room temperature, 4 exists as a diamagnetic pi-dimer (interplanar separation of approximately 3.1 A), whereas 3 is a paramagnetic pi-dimer (interplanar separation of approximately 3.3 A), and both compounds show phase transitions between the paramagnetic and diamagnetic forms. Electrical resistivity measurements of single crystals of 3 and 4 show that the transition from the high-temperature paramagnetic pi-dimer form to the low-temperature diamagnetic pi-dimer structure is accompanied by an increase in conductivity by about 2 orders of magnitude. This behavior is unprecedented and is very difficult to reconcile with the usual understanding of a Peierls dimerization, which inevitably leads to an insulating ground state. We tentatively assign the enhancement in the conductivity to a decrease in the on-site Coulombic correlation energy (U), as the dimers form a super-molecule with twice the amount of conjugation. PMID:11457155

  18. Quenching and radical formation in the reaction of photoexcited benzophenone with thiols and thioethers (sulfides). Nanosecond flash studies

    SciTech Connect

    Inbar, S.; Linschitz, H.; Cohen, S.G.

    1982-01-01

    Laser flash measurements have been made of rate constants and primary radical yields in the reactions of triplet benzophenone with aliphatic and aromatic thiols and with dialkyl and aryl alkyl sulfides. Reaction with n-pentylthiol in benzene leads mainly to quenching, with k/sub ir/ = 9 x 10/sup 6/ M/sup -1/ s/sup -1/ and radical yield (ketyl) = 0.14; with mesitylene-2 thiol in benzene k/sub ir/ = 7 x 10/sup 8/ M/sup -1/ s/sup -1/ and hydrogen transfer is efficient, radical yield (ketyl) approx. 1.0. In reactions with both p-chlorophenyl ethyl and diisopropyl sulfides, k/sub ir/ increases and radical yield (ketyl) decreases with increasing solvent polarity. Values of k/sub ir/ are higher and those of radical yield (ketyl) are lower for the dialkyl than for the aryl alkyl sulfide. Results are discussed in terms of rapid interaction of the triplet with S, followed by quenching and/or hydrogen transfer. Quenching without hydrogen transfer occurs to a much greater extent with sulfides and aliphatic thiols than with amines.

  19. Graphene oxide as a radical initiator: Free radical and controlled radical polymerization of sodium 4-vinylbenzenesulfonate with graphene oxide

    DOE PAGESBeta

    Voylov, Dmitry N.; Saito, Tomonori; Lokitz, Bradley S.; Uhrig, David; Wang, Yangyang; Agapov, Alexander L.; Holt, Adam P.; Bocharova, Vera; Kisliuk, Alexander; Sokolov, Alexei P.

    2016-01-19

    The free radical and controlled radical polymerization of sodium 4-vinylbenzenesulfonate using graphene oxide as a radical initiator was studied. This work demonstrates that graphene oxide can initiate radical polymerization in an aqueous solution without any additional initiator. Poly(sodium 4-vinylbenzenesulfonate) obtained via reversible addition fragmentation chain transfer polymerization had a controlled molecular weight with a very narrow polydispersity ranging between 1.01 and 1.03. Furthermore, the reduction process of graphene oxide as well as the resulting composite material properties were analyzed in detail.

  20. Genotoxicity and cytotoxicity assessment of new ethyl-carbamates with ixodicidal activity.

    PubMed

    Prado-Ochoa, María Guadalupe; Muñoz-Guzmán, Marco Antonio; Vázquez-Valadez, Víctor Hugo; Velázquez-Sánchez, Ana María; Salazar, Ana María; Ramírez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

    2016-09-01

    The mammalian erythrocyte micronucleus test was used on the peripheral blood of Wistar rats exposed to two new ethyl-carbamates: ethyl-4-bromophenyl-carbamate (LQM 919) and ethyl-4-chlorophenyl-carbamate (LQM 996) to analyze their genotoxic potential. The mitotic index and cell proliferation kinetics in human lymphocyte cultures in the presence of these ethyl-carbamates were used to evaluate cytotoxicity and cytostaticity respectively. Exposure to greater acute doses (300mg/kg) and to all of the subchronic doses (12.5, 25 and 50mg/kg daily for 90 days) of these ethyl-carbamates induced an increased frequency (p<0.05) of micro-nucleated polychromatic erythrocytes (MN-PCE) compared with rats not exposed to the ethyl-carbamates. Increases in MN-PCE was higher in males than in females exposed to LQM 996 50mg/Kg (p<0.05). All observed changes in rats return 21days after suspending ethyl-carbamate exposure. The highest concentration (0.3mM) of both ethyl-carbamates in lymphocyte cultures increased the percentage of cells in first division metaphase and decreased the percentage of cells in third division metaphase, indicating an increase in cell cycle length or a possible cell cycle arrest in metaphase (cytostatic effect). The results of this study show that the evaluated ethyl-carbamates may induce genotoxic damage in rats and alterations in the human lymphocyte cell cycle. PMID:27542710

  1. Radical formation and radiation damage in adamantane

    SciTech Connect

    Lloyd, R.V.; DiGregorio, S.; DiMauro, L.; Wood, D.E.

    1980-10-30

    Unequivocal samples of the 1-adamantyl (1-Ad) and 2-Ad radicals have been prepared in a matrix of adamantane (Ad) by the simultaneous deposition of atomic sodium, 1- or 2-bromoadamantane, and adamantance at 77 K. The EPR spectrum of the 1-Ad radical contrary to previous reports has a clearly resolved hyperfine structure that can be analyzed in terms of the solution parameters of Krusic et al., and the spectrum of the 2-Ad radical is identical with that previously reported by Ferrell et al. It is also shown that conditions of purification and irradiation can greatly affect the spectra obtained upon X irradiation of Ad itself. Depending upon conditions, alicyclic radicals that are primary products of ring-opening reactions or benzylic-type radicals that are probably secondary reaction products can also be obtained in addition to 1-Ad and 2-Ad radicals.

  2. [Free radicals in immunology and infectious diseases].

    PubMed

    Racek, J; Holecek, V; Sedlácek, D; Panzner, P

    2001-04-01

    Free radicals contribute significantly in modification of immune processes and inflammatory reactions. They are produced by activated phagocytes which use them for killing microorganisms. Free radicals facilitate production of cytokines, which are important as modifiers of inflammatory reactions. Formation of free radicals is influenced by antioxidants which can thus modify the intensity of inflammatory reaction and immune response. The authors describe in detail the contribution of free radicals in etiology and pathogenesis of autoimmune diseases including rheumatoid arthritis, multiple sclerosis or amyotrophic lateral sclerosis. The role of free radicals and modifying influence of antioxidants in viral, bacterial, parasitic and mycotic diseases is described in the second part of the review. Finally, influence of free radicals and antioxidants on immunity changes in patients with malignant tumours, during aging and physical exercise is discussed. PMID:11329733

  3. Detection of ethyl glucuronide in blood spotted on different surfaces.

    PubMed

    Winkler, M; Kaufmann, E; Thoma, D; Thierauf, A; Weinmann, W; Skopp, G; Alt, A

    2011-07-15

    This study aims to show that sensitive detection of ethyl glucuronide in dried blood spotted onto various surfaces after a period of 24h is feasible. At present, there is insufficient information how tightly ethyl glucuronide (EtG) binds to various materials and how easily it can be eluted. 4ml aliquots of blood samples obtained from seven volunteers after consumption of alcoholic beverages were applied to six different surfaces. After drying and a 24h-storage at 20±2°C the samples were re-dissolved in water, and EtG was subsequently analyzed by a LC-MS Paul-type ion trap. A comparison was made between dried and corresponding fluid samples. EtG was detectable in all subjects' samples following consumption of alcohol. EtG was also detectable after a storage time of four weeks at 4°C in whole blood that had been preserved with EDTA. EtG was detectable in all samples dried on different surfaces and its concentration remained relatively constant irrespective of the particular condition of the material. Detection of EtG in blood spots from the scene may indicate recent alcohol consumption in cases where collection of blood remained undone or could not be performed. PMID:21641739

  4. Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

    PubMed Central

    Kelle, Ilker; Akkoc, Hasan; Tunik, Selcuk; Nergiz, Yusuf; Erdinc, Meral; Erdinc, Levent

    2014-01-01

    This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringer's lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringer's EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity. PMID:26019553

  5. DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION

    SciTech Connect

    Tercero, B.; Cernicharo, J.; Lopez, A.; Caro, G. M. Munoz; Kleiner, I.; Nguyen, H. V. L. E-mail: jcernicharo@cab.inta-csic.es E-mail: munozcg@cab.inta-csic.es E-mail: nguyen@pc.rwth-aachen.de

    2013-06-10

    We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.

  6. Transesterification process to manufacture ethyl ester of rape oil

    SciTech Connect

    Korus, R.A.; Hoffman, D.S.; Bam, N.; Peterson, C.L.; Drown, D.C.

    1993-12-31

    A process for the production of the ethyl ester of winter rape [EEWR] for use as a biodiesel fuel has been studied. The essential part of the process is the transesterification of rape oil with ethanol, in the presence of a catalyst, to yield the ethyl ester of rape oil as a product and glycerin as a by-product. Experiments have been performed to determine the optimum conditions for the preparation of EEWR. The process variables were: (1) temperature, (2) catalyst, (3) rate of agitation, (4) water content of the alcohol used, and (5) the amount of excess alcohol used. The optimum conditions were: (1) room temperature, (2) 0.5% sodium methoxide or 1% potassium hydroxide catalyst by weight of rapeseed oil, (3) extremely vigorous agitation with some splashing during the initial phase of the reaction and agitation was not necessary after the reaction mixture became homogeneous, (4) absolute ethanol was necessary for high conversion, and (5) 50% excess ethanol with NaOCH{sub 3} or 100% excess with KOH gave a maximum conversion. Viscosity, cloud point and pour point of the EEWR were measured. A preliminary break-even cost for the commercial production of EEWR was found to be $0.55/liter [$2.08/US gallon].

  7. Spectroscopic detection, characterization and dynamics of free radicals relevant to combustion processes

    SciTech Connect

    Miller, Terry

    2015-06-04

    Combustion chemistry is enormously complex. The chemical mechanisms involve a multitude of elementary reaction steps and a comparable number of reactive intermediates, many of which are free radicals. Computer simulations based upon these mechanisms are limited by the validity of the mechanisms and the parameters characterizing the properties of the intermediates and their reactivity. Spectroscopy can provide data for sensitive and selective diagnostics to follow their reactions. Spectroscopic analysis also provides detailed parameters characterizing the properties of these intermediates. These parameters serve as experimental gold standards to benchmark predictions of these properties from large-scale, electronic structure calculations. This work has demonstrated the unique capabilities of near-infrared cavity ringdown spectroscopy (NIR CRDS) to identify, characterize and monitor intermediates of key importance in complex chemical reactions. Our studies have focussed on the large family of organic peroxy radicals which are arguably themost important intermediates in combustion chemistry and many other reactions involving the oxidation of organic compounds. Our spectroscopic studies have shown that the NIR Ã - ˜X electronic spectra of the peroxy radicals allows one to differentiate among chemical species in the organic peroxy family and also determine their isomeric and conformic structure in many cases. We have clearly demonstrated this capability on saturated and unsaturated peroxy radicals and β-hydroxy peroxy radicals. In addition we have developed a unique dual wavelength CRDS apparatus specifically for the purpose of measuring absolute absorption cross section and following the reaction of chemical intermediates. The utility of the apparatus has been demonstrated by measuring the cross-section and self-reaction rate constant for ethyl peroxy.

  8. Electron spin resonance spectra of nitroxyl radicals

    NASA Astrophysics Data System (ADS)

    Botek, Edith; Zarycz, Natalia; Champagne, Benoît; Sciannaméa, Valérie; Detrembleur, Christophe

    2012-12-01

    Hyperfine coupling constants (HFCCs) of nitroxyl radicals were calculated using density functional theory (DFT) to address the structure of nitroxide intermediates in controlled radical polymerization. In a preliminary step, the reliability of different theoretical methods has been substantiated by comparing calculated HFCCs to experimental data for a set of acyclic and cyclic alkylnitroxyl radicals. In a second step this tested approach was applied to support experimental evidence of several nitroxide-mediated polymerization (NMP) reactions.

  9. Quantitative determination of atmospheric hydroperoxyl radical

    DOEpatents

    Springston, Stephen R.; Lloyd, Judith; Zheng, Jun

    2007-10-23

    A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.

  10. Free-radical chemistry of sulfite

    SciTech Connect

    Neta, P.; Huie, R.E.

    1985-12-01

    The free-radical chemistry of sulfite oxidation is reviewed. Chemical transformations of organic and biological molecules induced by sulfite oxidation are summarized. The kinetics of the free-radical oxidations of sulfite are discussed, as are the kinetics of the reactions of the sulfite-derived radicals SO/sub 3/ and the peroxy derivative SO/sub 5/ with organic compounds. 98 references.

  11. Energetics of mechanical destruction of middle radicals

    NASA Astrophysics Data System (ADS)

    Kvachadze, N. G.; Tomashevskii, E. E.; Zhizhenkov, V. V.

    2015-11-01

    The breaking strain of a model fragment of a middle radical in a rigid polymer matrix has been calculated. The force and energy characteristics of the destruction of the radical and the formation of double bonds have been estimated. The dissociation energy and the strength of Cβ-Cγ bonds for trans- and gaucheconformers of radicals have been determined. It has been established that the probability of breaking of the β bonds essentially depends of the conformation structure of the macroradicals.

  12. Determination of Radical Scavenging Activity and Total Phenols of Wine and Spices: A Randomized Study.

    PubMed

    Lugemwa, Fulgentius Nelson; Snyder, Amanda L; Shaikh, Koonj

    2013-01-01

    Thirty eight bottles of red wine (Carbanet Sauvignon) were randomly selected based on vintage, region, price, and age (number of months in a barrel). The total phenolic content of each wine was determined using Folin-Ciocalteau assay. The radical scavenging activity was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Apart from a few bottles that exhibited above average radical scavenging activity and phenolic content, there was no good correlation of those two quantities with region, price or vintage. The average phenolic amount was 2874 mg/L. The lowest phenolic content was found to be 1648 mg/L for an eight dollar wine. Wine with the highest amount of phenol of 4495 mg/L was a 2007, nine dollar bottle from South America. High amount of phenols did not translate into high radical scavenging activity. Barrel-aging did not increase the amount of phenols or the radical scavenging activity of wine. In order to discover new and potent sources of antioxidants from plants, the following spices were studied: ginger, cilantro, cumin, anise, linden, eucalyptus, marjoram, oregano, sage, thyme and rosemary. Whole spices were crushed and extracted for 96 h at room temperature using a combination of ethyl acetate, ethyl alcohol and water in the ratio of 4.5:4.5:1 (v/v/v). The radical scavenging activity of extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. The total phenolic content of each spice was also determined using the Folin-Ciocalteau assay. Eucalyptus was found to be the most potent antioxidant with an LC50 of 324.1 mg of phenol/L, followed by marjoram with an LC50 of 407.5 mg of phenol/L, and rosemary with an LC50 of 414.0 mg/L. The least potent antioxidants were ginger and cilantro with LC50 of 7604 mg/L of phenol and 7876 mg of phenol/L, respectively. PMID:26784340

  13. Determination of Radical Scavenging Activity and Total Phenols of Wine and Spices: A Randomized Study

    PubMed Central

    Lugemwa, Fulgentius Nelson; Snyder, Amanda L.; Shaikh, Koonj

    2013-01-01

    Thirty eight bottles of red wine (Carbanet Sauvignon) were randomly selected based on vintage, region, price, and age (number of months in a barrel). The total phenolic content of each wine was determined using Folin-Ciocalteau assay. The radical scavenging activity was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Apart from a few bottles that exhibited above average radical scavenging activity and phenolic content, there was no good correlation of those two quantities with region, price or vintage. The average phenolic amount was 2874 mg/L. The lowest phenolic content was found to be 1648 mg/L for an eight dollar wine. Wine with the highest amount of phenol of 4495 mg/L was a 2007, nine dollar bottle from South America. High amount of phenols did not translate into high radical scavenging activity. Barrel-aging did not increase the amount of phenols or the radical scavenging activity of wine. In order to discover new and potent sources of antioxidants from plants, the following spices were studied: ginger, cilantro, cumin, anise, linden, eucalyptus, marjoram, oregano, sage, thyme and rosemary. Whole spices were crushed and extracted for 96 h at room temperature using a combination of ethyl acetate, ethyl alcohol and water in the ratio of 4.5:4.5:1 (v/v/v). The radical scavenging activity of extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. The total phenolic content of each spice was also determined using the Folin-Ciocalteau assay. Eucalyptus was found to be the most potent antioxidant with an LC50 of 324.1 mg of phenol/L, followed by marjoram with an LC50 of 407.5 mg of phenol/L, and rosemary with an LC50 of 414.0 mg/L. The least potent antioxidants were ginger and cilantro with LC50 of 7604 mg/L of phenol and 7876 mg of phenol/L, respectively. PMID:26784340

  14. Spin trapping of radicals in tritiated methanol

    NASA Astrophysics Data System (ADS)

    Halpern, A.

    1984-01-01

    The radicals in [methyl- 3H]-methanol have been detected by spin trapping with PBN. Two radicals observed in deaerated samples at 273 K are methoxy and hydroxymethyl radicals. The relative contribution of these two radicals changes with the storage time, finally only the PBNCH 2OH adduct being observed. This behaviour is hypothetically explained as resulting from the secondary reactions with a product formed in methanol by internal β-radiolysis or otherwise, whose steadily increasing concentration accelerates the decay of the PBNCH 3O adduct.

  15. Physiological aspects of free-radical reactions.

    PubMed Central

    Yamazaki, I; Tamura, M; Nakajima, R; Nakamura, M

    1985-01-01

    Enzymes which catalyze the formation of free radicals in vitro will catalyze similar reactions in vivo. We believe that the formation of some kinds of free radicals has definite physiological meanings in metabolism. In this sense, the enzymes forming such free radicals are concluded to be in evolutionally advanced states. Elaborated structure and function of enzymes such as horseradish peroxidase and microsomal flavoproteins support the idea. Deleterious and side reactions caused by free radicals are assumed to be minimized in vivo by localizing the reactions, but this assumption should be verified by future studies. PMID:3007098

  16. Dynamics of Radical-Mediated Enzyme Catalyses

    NASA Astrophysics Data System (ADS)

    Warncke, Kurt

    1997-11-01

    An emergent class of enzymes harnesses the extreme reactivity of electron-deficient free radical species to perform some of the most difficult reactions in biology. The regio- and stereo-selectivity achieved by these enzymes defies long-held ideas that radical reactions are non-specific. The common primary step in these catalyses is metal- or metallocenter-assisted generation of an electron-deficient organic "initiator radical". The initiator radical abstracts a hydrogen atom from the substrate, opening a new reaction channel for rearrangement to the product. Our aim is to elucidate the detailed molecular mechanisms of the radical pair separation and radical rearrangement steps. Radical pair separation and substrate radical rearrangement are tracked by using time-resolved (10-7 to 10-3 s) techniques of pulsed-electron paramagnetic resonance spectroscopy (FT-EPR, ESEEM). Synchronous time-evolution of the reactions is attained by triggering with a visible laser pulse. Transient non-Boltzmann population of the states of the spin-coupled systems, and resultant electron spin polarization, facilitates study at or near room temperature under conditions where the enzymes are operative. The systems examined include ethanolamine deaminase, a vitamin B12 coenzyme-dependent enzyme, ribonucleotide reductase and photosynthetic reaction centers. The electronic and nuclear structural and kinetic information obtained from the pulsed-EPR studies is used to address how the initiator radicals are stabilized against deleterious recombination with the metal, and to distinguish the participation of concerted versus sequential rearrangement pathways.

  17. Effects of electron acceptors and radical scavengers on nonchain radical nucleophilic substitution reactions

    SciTech Connect

    Xianman Zhang; Dilun Yang; Youcheng Liu )

    1993-01-01

    The yields of reaction products from thermal nucleophilic substitution reactions in dimethyl sulfoxide (DMSO) of six o- and p-nitrohalobenzenes with the sodium salt of ethyl [alpha]-cyanoacetate carbanion [Na[sup +][sup [minus

  18. DNA Binding Hydroxyl Radical Probes

    PubMed Central

    Tang, Vicky J; Konigsfeld, Katie M; Aguilera, Joe A; Milligan, Jamie R

    2011-01-01

    The hydroxyl radical is the primary mediator of DNA damage by the indirect effect of ionizing radiation. It is a powerful oxidizing agent produced by the radiolysis of water and is responsible for a significant fraction of the DNA damage associated with ionizing radiation. There is therefore an interest in the development of sensitive assays for its detection. The hydroxylation of aromatic groups to produce fluorescent products has been used for this purpose. We have examined four different chromophores which produce fluorescent products when hydroxylated. Of these, the coumarin system suffers from the fewest disadvantages. We have therefore examined its behavior when linked to a cationic peptide ligand designed to bind strongly to DNA. PMID:22125376

  19. Students' Ideas and Radical Constructivism

    NASA Astrophysics Data System (ADS)

    Sánchez Gómez, Pedro J.

    2016-04-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of narrow mental states; that is, the idea that the mental content of an individual can be fully characterised without any reference external to her or him. I show that this fact imposes some severe restrictions to SIS to be incorporated into RC. In particular, I argue that only qualitative studies can comply with the requirement of narrowness. Nevertheless, I propose that quantitative works can be employed as sources of types in order to study token actual students. I use this type-token dichotomy to put forward an outline of a theory of the relation between school contents and mental contents. In this view, token mental contents regarding a given topic can be defined, and probed, only by resorting to typical school contents.

  20. Students' Ideas and Radical Constructivism

    NASA Astrophysics Data System (ADS)

    Sánchez Gómez, Pedro J.

    2016-08-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of narrow mental states; that is, the idea that the mental content of an individual can be fully characterised without any reference external to her or him. I show that this fact imposes some severe restrictions to SIS to be incorporated into RC. In particular, I argue that only qualitative studies can comply with the requirement of narrowness. Nevertheless, I propose that quantitative works can be employed as sources of types in order to study token actual students. I use this type-token dichotomy to put forward an outline of a theory of the relation between school contents and mental contents. In this view, token mental contents regarding a given topic can be defined, and probed, only by resorting to typical school contents.

  1. Radical surgery in septic abortion.

    PubMed

    Chatterjee, P; Ghosh, M; Ghosh, S

    1979-08-01

    At R.G. Kar Medical College Hospital, Calcutta, 10 cases of septic abortion from 1975-1977 were studied. Hysterectomies were preformed on 4 cases due to emergency situations including traumatised uterine fundus and perforated cervix, and on 6 cases after conservative treatment. Upon performing laparotomy in 9 cases, a uterine rent was detected; in 1 case there was a perforation in the posterior wall of the cervix, and in 5 cases mechanical obstructions due to internal adhesions to the uterine rent were found. 4 patients died primarily because of the patients seeking help too late. It is suggested that under high risk circumstances, laparotomy is advantageous to conservative medical management since bowel injuries and mechanical obstructions can only be detected by laparotomy. Radical surgery, however, should be undertaken before the patients general condition deteriorates to the point that the patient cannot tolerate surgical intervention. PMID:12336028

  2. Free radicals and ocular disease.

    PubMed

    Anderson, R E; Kretzer, F L; Rapp, L M

    1994-01-01

    Ames, Shigenaga, and Hagen recently published a thorough review of the relationship between oxidants, antioxidants, and degenerative diseases of ageing. They point out that only 9% of Americans daily consume the two fruits and three vegetables recommended by the National Cancer Institute and the National Research Council/National Academy of Science. In addition to antioxidants, these foodstuffs contain many essential micronutrients. To date, specific recommendations for antioxidant supplementation have not been made by any governmental agency or professional association. A number of clinical, basic, and epidemiological studies have implicated free radical induced lipid peroxidation in various ocular disorders. It would seem prudent that those persons at greatest risk for these disorders take some precautions, which could include sunglasses that filter ultraviolet light; hats that shield the eyes from direct sunlight; and the ingestion of fruits, vegetables, and antioxidants. PMID:7771292

  3. Peroxy radical measurements with NCAR's chemical amplifier

    NASA Technical Reports Server (NTRS)

    Cantrell, Christopher; Shetter, Richard; Calvert, Jack G.

    1994-01-01

    The present NCAR instrument for HO2/RO2 measurements has been described previously. It is based on the reactions involving HO2, RO2, and HO radicals with CO and NO. Since (HO2) + (RO2) + (HO) is much greater than (HO) for most atmospheres, it is useful as a peroxy radical detector. Operation of the instrument depends on the creation of a chemical chain reaction which is initiated as HO2 and RO2 radicals in ambient air encounter added NO gas; this forms an NO2 molecule and an HO or RO radical: HO2(RO2) + NO yields HO(RO) + NO2. RO radicals react relatively efficiently with O2 to form an HO2 radical, and subsequently an HO-radical, by reaction with NO. CO gas added to the reaction chamber during part of the operating cycle, recycles the HO to HO2; HO + CO (+O2) yields HO2 + CO2. The reaction sequence may form several hundred NO2 molecules per HO2 (RO2) originally present, before chain termination occurs. The added CO is replaced by N2 addition periodically so that the chain reaction is suppressed, and a 'blank' signal resulting from NO2, O3 and possibly other NO2-forming species (non-chain processes) in ambient air is recorded. The difference between the signal with and without CO is proportional to the peroxy radical concentration. The NO2 produced is monitored using a sensitive luminol chemiluminescence detector system. In the NCAR instrument the length of the amplification chain is determined using a stable source of HO2 radicals (H2O2 thermal decomposition); the ratio of the signal seen with CO present to that with N2 present gives the sensitivity of the instrument to HO2 (molecules of NO2 formed/peroxy radical). The instrument is automated to carry out in hourly repeated cycles: (1) chain length determination; (2) NO2 calibration; and (3) linearity check on the response of signals. One minute averages of signals are normally recorded. The sensitivity of the instrument to detect peroxy radicals is in the pptv range. The present instrument has operated

  4. Inhibition of dual-specificity phosphatase 26 by ethyl-3,4-dephostatin: Ethyl-3,4-dephostatin as a multiphosphatase inhibitor.

    PubMed

    Seo, Huiyun; Cho, Sayeon

    2016-04-01

    Protein tyrosine phosphatases (PTPs) regulate protein function by dephosphorylating phosphorylated proteins in many signaling cascades and some of them have been targets for drug development against many human diseases. There have been many reports that some chemical inhibitors could regulate particular phosphatases. However, there was no extensive study on specificity of inhibitors towardss phosphatases. We investigated the effects of ethyl-3,4-dephostatin, a potent inhibitor of five PTPs including PTP-1B and Src homology-2-containing protein tyrosine phosphatase-1 (SHP-1), on thirteen other PTPs using in vitro phosphatase assays. Of them, dual-specificity protein phosphatase 26 (DUSP26), which inhibits mitogen-activated protein kinase (MAPK) and p53 tumor suppressor and is known to be overexpressed in anaplastic thyroid carcinoma, was inhibited by ethyl-3,4-dephostatin in a concentration-dependent manner. Kinetic studies with ethyl-3,4-dephostatin and DUSP26 revealed competitive inhibition, suggesting that ethyl-3,4-dephostatin binds to the catalytic site of DUSP26 like other substrate PTPs. Moreover, ethyl-3,4-dephostatin protects DUSP26-mediated dephosphorylation of p38, a member of the MAPK family, and p53. Taken together, these results suggest that ethyl-3,4-dephostatin functions as a multiphosphatase inhibitor and is useful as a therapeutic agent for cancers overexpressing DUSP26. PMID:27209699

  5. Fabrication of polymerized crystalline colloidal array thin film modified β-cyclodextrin polymer for paraoxon-ethyl and parathion-ethyl detection.

    PubMed

    Bui, Minh-Phuong N; Seo, Seong S

    2014-01-01

    We have developed an optical chemical sensor for the detection of organophosphate (OP) compounds using a polymerized crystalline colloidal array (PCCA) thin film composed of a close-packed colloidal array of polystyrene particles. The PCCA thin film was modified with β-cyclodextrin (β-CD) polymer as a capping cavity for the selective detection of paraoxon-ethyl and parathion-ethyl chemical agents. The fabrication of the modified PCCA thin film was optimized and the structure was characterized using scanning electron microscopy (SEM). The arrangement of polystyrene particles in the PCCA follows a pattern of the fcc (111) planes with strong diffraction peak in the visible spectral region and pH dependence. The diffraction peak of the β-CD modified PCCA thin film showed a red shift according to the change of paraoxon-ethyl and parathion-ethyl concentrations at a fast response time (10 s) and high sensitivity with detection limits of 2.0 and 3.4 ppb, respectively. Furthermore, the proposed interaction mechanism of β-CD with paraoxon-ethyl and parathion-ethyl in the β-CD modified PCCA thin film were discussed. PMID:24813957

  6. 40 CFR 180.662 - Trinexapac-ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Trinexapac-ethyl; tolerances for residues. 180.662 Section 180.662 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.662 Trinexapac-ethyl; tolerances...

  7. 40 CFR 180.662 - Trinexapac-ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Trinexapac-ethyl; tolerances for residues. 180.662 Section 180.662 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.662 Trinexapac-ethyl; tolerances...

  8. 40 CFR 180.585 - Pyraflufen-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Pyraflufen-ethyl; tolerances for residues. 180.585 Section 180.585 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.585 Pyraflufen-ethyl; tolerances...

  9. 78 FR 9938 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ... recent previous determination for the 2012 amount in the Federal Register on December 30, 2011 (76 FR... COMMISSION Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports AGENCY: United States... is equal to 7 percent of the U.S. domestic market for fuel ethyl alcohol during the 12-month...

  10. 40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a)...

  11. 40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a)...

  12. 40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a)...

  13. 40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a)...

  14. 40 CFR 721.445 - Substituted ethyl alken-a-mide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.445 Substituted ethyl alken-a-mide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted ethyl...

  15. 40 CFR 721.445 - Substituted ethyl alken-a-mide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.445 Substituted ethyl alken-a-mide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted ethyl...

  16. Solid Dose Form of Metformin with Ethyl Eicosapentaenoic Acid Does Not Improve Metformin Plasma Availability

    PubMed Central

    Burton, Jeffrey H.; Johnson, William D.; Greenway, Frank L.

    2016-01-01

    Background The purpose of the study was to investigate effects of ethyl eicosapentaenoic acid on pharmacokinetics of metformin. Pharmacokinetic profiles of metformin and ethyl eicosapentaenoic acid when delivered separately or together in solid dose form were investigated and compared to determine whether the solid dose resulted in an altered metforminpharmacokinetics when given with or without food. Methods A single-center, open-label, repeated dose study investigated the pharmacokinetic (PK) profile of metformin when administered in solid dose form with ethyl eicosapentaenoic acid compared to co-administration with icosapent ethyl, an ester of eicosapentaenoic acid and ethyl alcohol used to treat severe hypertriglyceridemia with metformin hydrochloride. Non-compartmental PK methods were used to compare area under the plasma concentration curve (AUC) and maximum plasma concentration (Cmax) between patients randomized to either the ester or separate medications group under both fasting and fed conditions. Results Using these two PK parameters, results showed that metformin availability was higher under fasting conditions when delivered separately from icosapent ethyl. There were no group differences in the fed condition. Conclusions The solid dose form of metformin and ethyl eicosapentaenoic acid did not improve the pharmacokinetics of metformin in terms of plasma availability, suggesting that little is to be gained over the separate administration of ethyl eicosapentaenoic acid and metformin hydrochloride. PMID:26893954

  17. Survey of ethyl carbamate in fermented foods sold in the United Kingdom in 2004.

    PubMed

    Hasnip, Sarah; Crews, Colin; Potter, Nicholas; Christy, Julie; Chan, Danny; Bondu, Thomas; Matthews, Wendy; Walters, Barry; Patel, Krishna

    2007-04-01

    Results are presented of a survey of fermented foods and beverages sold in the United Kingdom for levels of ethyl carbamate (urethane) carried out to expand the range of food types sold in the United Kingdom for which data regarding ethyl carbamate are available. Samples were analyzed by in-house validated methods, which included measurement uncertainty estimates. The samples comprised 75 fermented liquids (beers, wines, fortified wines, spirits, liqueurs, soy sauces, and vinegars) and 25 fermented solid foods (cheeses, yogurts, soybean products, sauerkraut, yeast extract, olives, and Christmas pudding). Ethyl carbamate was not detected in the beers or the cider. Wines contained between 11 and 24 microg/kg and sake between 81 and 164 microg/kg. Fortified wines contained ethyl carbamate at levels between 14 and 60 microg/kg. Only two of five liqueurs contained ethyl carbamate. Most soy sauces and vinegars did not contain ethyl carbamate. No ethyl carbamate was detected in cheeses, yogurts, olives, or soybean-based products. Single samples of sauerkraut, yeast extract, and Christmas pudding contained low levels (29, 41, and 20 microg/kg ethyl carbamate, respectively). PMID:17328558

  18. Controlled Degradation of Poly(Ethyl Cyanoacrylate-Co-Methyl Methacrylate)(PECA-Co-PMMA) Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes a method for modifying poly(ethyl cyanoacrylate) in order to control the degradation and the stability as well as the glass transition temperatures. Copolymers of poly(ethyl cyanoacrylate-co-methyl methacrylate) (PECA-co-PMMA) with various compositions were synthesized by free ...

  19. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  20. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  1. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  2. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  3. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  4. Novel in vivo active anti-malarials based on a hydroxy-ethyl-amine scaffold.

    PubMed

    Ciana, Claire-Lise; Siegrist, Romain; Aissaoui, Hamed; Marx, Léo; Racine, Sophie; Meyer, Solange; Binkert, Christoph; de Kanter, Ruben; Fischli, Christoph; Wittlin, Sergio; Boss, Christoph

    2013-02-01

    A novel series of anti-malarials, based on a hydroxy-ethyl-amine scaffold, initially identified as peptidomimetic protease inhibitors is described. Combination of the hydroxy-ethyl-amine anti-malarial phramacophore with the known Mannich base pharmacophore of amodiaquine (57) resulted in promising in vivo active novel derivatives. PMID:23260352

  5. Ethyl levulinate: A potential bio-based diluent for biodiesel which improves cold flow properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The physical properties of biodiesel from soybean, canola, cottonseed and poultry fat methyl esters were improved with addition of ethyl levulinate with increasing concentration. The effect of adding ethyl levulinate was determined by studying its influence on the acid value, cloud point, pour point...

  6. Alex Bloom, Pioneer of Radical State Education

    ERIC Educational Resources Information Center

    Fielding, Michael

    2005-01-01

    Alex Bloom is one of the greatest figures of radical state education in England. His approach to "personalised learning" and the development of a negotiated curriculum was immeasurably more profound and more inspiring than anything to emerge thus far from the current DfES. His approach to student voice was much more radical than anything presently…

  7. Radical Behaviorism and Buddhism: Complementarities and Conflicts

    ERIC Educational Resources Information Center

    Diller, James W.; Lattal, Kennon A.

    2008-01-01

    Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism. The present review therefore considers heretofore unconsidered points of comparison between Buddhism and radical behaviorism in terms of their…

  8. Rearrangement of sulfonamidyl radicals with hydrogen migration

    SciTech Connect

    Troyanskii, E.I.; Lazareva, M.I.; Nikishin, G.I.

    1987-01-20

    One-step outlying oxidative chlorination of alkanesulfonamides by the action of the Na/sub 2/S/sub 2/O/sub 8/-CuCl/sub 2/ system via intermediate sulfonamidyl radicals gives 3- and 4-chloroalkanesulfonamides. Rearrangements of sulfonamidyl radicals with H atom migration from the sulfonyl segment predominates over rearrangement with H atom migration from the amide segment.

  9. What Is Radical in School Geography Today?

    ERIC Educational Resources Information Center

    Morgan, John

    2011-01-01

    This article addresses the question of what "radical school geography" might look like in the present historical moment. It traces the history of a distinctive "radical" tradition in school geography, most prominently associated with the work of John Huckle, who argued for the importance of understanding the content and pedagogy of school…

  10. Oxygen radical production by avian leukocytes.

    PubMed

    Conlon, P; Smith, D; Gowlett, T

    1991-04-01

    Oxygen radical production by heterophils of red-tailed hawks and chickens, and by neutrophils of calves, was evaluated in a chemiluminescence microassay. Leukocytes were isolated by centrifugation of blood in capillary tubes and then challenged with opsonized zymosan in the presence of luminol. Avian heterophils produced significantly fewer oxygen radicals than did bovine neutrophils. PMID:1884301

  11. Free Radical Mechanisms in Autoxidation Processes.

    ERIC Educational Resources Information Center

    Simic, Michael G.

    1981-01-01

    Discusses the use of steady-state radiation chemistry and pulse radiolysis for the generation of initial free radicals and formation of peroxy radicals in the autoxidation process. Provides information regarding the autoxidation process. Defines autoxidation reactions and antioxidant action. (CS)

  12. Radical Voices; A Film Course Study Guide.

    ERIC Educational Resources Information Center

    Kernan, Margot

    The leftist radical ideas current in the 1960s and 1970s are expressed in the films discussed in this cinema study guide. The radical film takes extreme and avant-garde approaches to the somewhat publicly taboo topics of sex, social issues, and religion. Among the films discussed, I AM CURIOUS (YELLOW) and SOMETHING DIFFERENT show women in their…

  13. Radical Constructivism: Between Realism and Solipsism.

    ERIC Educational Resources Information Center

    Martinez-Delgado, Alberto

    2002-01-01

    Criticizes radical constructivism of the Glasersfeld type, pointing out some contradictions between the declared radical principles and their theoretical and practical development. Suggests the possibility of an ideological substratum in the construction and hegemonic success of subjective constructivism, and briefly advances an alternative…

  14. Ideals Adrift: An Educational Approach to Radicalization

    ERIC Educational Resources Information Center

    van San, Marion; Sieckelinck, Stijn; de Winter, Micha

    2013-01-01

    These days, the radicalization of young people is above all viewed as a security risk. Almost all research into this phenomenon has been carried out from a legal, criminological or socio-psychological perspective with a focus on detecting and containing the risks posed by radicalization. In the light of the political developments since September…

  15. Electrophilicity and nucleophilicity index for radicals.

    PubMed

    De Vleeschouwer, Freija; Van Speybroeck, Veronique; Waroquier, Michel; Geerlings, Paul; De Proft, Frank

    2007-07-01

    Radicals can be regarded as electrophilic/nucleophilic, depending on their tendency to attack sites of relatively higher/lower electron density. In this paper, an electrophilicity scale, global as well as local, and a nucleophilicity scale for 35 radicals is reported. The global electrophilicity scale correlates well with the nucleophilicity scale, suggesting that these concepts are inversely related. PMID:17559221

  16. Torsional barrier and equilibrium structure of ethyl cyanide

    NASA Astrophysics Data System (ADS)

    Demaison, J.; Margulès, L.; Mäder, H.; Sheng, M.; Rudolph, H. D.

    2008-12-01

    The quadratic, cubic and semi-diagonal quartic force field of ethyl cyanide has been calculated at the B3LYP level of theory employing a basis set of triple-ζ quality. A semi-experimental equilibrium structure has been derived from experimental ground state rotational constants and rovibrational interaction parameters calculated from the ab initio force field. This structure is in excellent agreement with the ab initio structure calculated at the CCSD(T) level of theory using a basis set of quadruple-ζ quality and a core correlation correction. The empirical structures are also determined and their accuracy is discussed. The potential barrier V3 hindering internal rotation of the methyl group has been calculated from 23 rotational transitions of CH 3CH 2C 15N which were found split into doublets, giving V3 = 3074(27) cal mol -1.

  17. Interaction of Ethyl Alcohol Vapor with Sulfuric Acid Solutions

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun

    2006-01-01

    We investigated the uptake of ethyl alcohol (ethanol) vapor by sulfuric acid solutions over the range approx.40 to approx.80 wt % H2SO4 and temperatures of 193-273 K. Laboratory studies used a fast flow-tube reactor coupled to an electron-impact ionization mass spectrometer for detection of ethanol and reaction products. The uptake coefficients ((gamma)) were measured and found to vary from 0.019 to 0.072, depending upon the acid composition and temperature. At concentrations greater than approx.70 wt % and in dilute solutions colder than 220 K, the values approached approx.0.07. We also determined the effective solubility constant of ethanol in approx.40 wt % H2SO4 in the temperature range 203-223 K. The potential implications to the budget of ethanol in the global troposphere are briefly discussed.

  18. Ethyl carbamate levels in selected fermented foods and beverages.

    PubMed

    Canas, B J; Havery, D C; Robinson, L R; Sullivan, M P; Joe, F L; Diachenko, G W

    1989-01-01

    Ethyl carbamate (EC), also known as urethane, is an animal carcinogen and a by-product of fermentation. Because EC has been found in distilled spirits and wines, a variety of fermented foods and beverages were analyzed to assess its occurrence in other products. Previously described methods using a gas chromatograph-thermal energy analyzer with a nitrogen converter were modified for each matrix and gave recoveries of greater than 80%, with a limit of detection in the 1-2 micrograms/kg (ppb) range. A total of 152 test samples were analyzed; EC levels ranged from none found to 3 ppb in 15 cheeses, 6 teas, 12 yogurts, and 8 ciders; from none found to 13 ppb in 30 breads and 69 malt beverages; and from none found to 84 ppb in 12 soy sauces. Gas chromatography/mass spectrometry/mass spectrometry was used to confirm EC identity and to quantitate EC in selected food extracts. PMID:2592308

  19. Alkaline hydrolysis of n-ethyl-2,4-dinitroacetanilide

    SciTech Connect

    Skarzewski, J.; Aoki, M.; Sekiquchi, S.

    1982-04-23

    The alkaline hydrolyses of anilides have been studied extensively, but those of anilides bearing ortho substituents seem to be a rather unexplored field. As was shown for p-nitroacetanilide (1), the reaction mechanism of the base-catalyzed hydrolyses of anilides with strongly electron-withdrawing substituents on the phenyl moiety differs somewhat from the general one. The difference is caused by higher acidity of leaving-group nitroanilines. The results obtained in the case of the alkaline hydrolysis of N-ethyl-2,4-dinitroacetanilide are expected to conform to the reaction mechanism proposed for all other anilides, but the rate-determining step may change for such sterically hindered derivatives. That this prediction is fulfilled will be developed in latter sections.

  20. Roaming radical pathways for the decomposition of alkanes.

    SciTech Connect

    Harding, L. B.; Klippenstein, S. J.

    2010-01-01

    CASPT2 calculations predict the existence of roaming radical pathways for the decomposition of propane, n-butane, isobutane and neopentane. The roaming radical paths lead to the formation of an alkane and an alkene instead of the expected radical products. The predicted barriers for the roaming radical paths lie {approx}1 kcal/mol below the corresponding radical asymptotes.

  1. High-yield synthesis of bioactive ethyl cinnamate by enzymatic esterification of cinnamic acid.

    PubMed

    Wang, Yun; Zhang, Dong-Hao; Zhang, Jiang-Yan; Chen, Na; Zhi, Gao-Ying

    2016-01-01

    In this paper, Lipozyme TLIM-catalyzed synthesis of ethyl cinnamate through esterification of cinnamic acid with ethanol was studied. In order to increase the yield of ethyl cinnamate, several media, including acetone, isooctane, DMSO and solvent-free medium, were investigated in this reaction. The reaction showed a high yield by using isooctane as reaction medium, which was found to be much higher than the yields reported previously. Furthermore, several parameters such as shaking rate, water activity, reaction temperature, substrate molar ratio and enzyme loading had important influences on this reaction. For instance, when temperature increased from 10 to 50 °C, the initial reaction rate increased by 18 times and the yield of ethyl cinnamate increased by 6.2 times. Under the optimum conditions, lipase-catalyzed synthesis of ethyl cinnamate gave a maximum yield of 99%, which was of general interest for developing industrial processes for the preparation of ethyl cinnamate. PMID:26213020

  2. Lipase-mediated conversion of vegetable oils into biodiesel using ethyl acetate as acyl acceptor.

    PubMed

    Modi, Mukesh Kumar; Reddy, J R C; Rao, B V S K; Prasad, R B N

    2007-04-01

    Ethyl acetate was explored as an acyl acceptor for immobilized lipase-catalyzed preparation of biodiesel from the crude oils of Jatropha curcas (jatropha), Pongamia pinnata (karanj) and Helianthus annuus (sunflower). The optimum reaction conditions for interesterification of the oils with ethyl acetate were 10% of Novozym-435 (immobilized Candida antarctica lipase B) based on oil weight, ethyl acetate to oil molar ratio of 11:1 and the reaction period of 12h at 50 degrees C. The maximum yield of ethyl esters was 91.3%, 90% and 92.7% with crude jatropha, karanj and sunflower oils, respectively under the above optimum conditions. Reusability of the lipase over repeated cycles in interesterification and ethanolysis was also investigated under standard reaction conditions. The relative activity of lipase could be well maintained over twelve repeated cycles with ethyl acetate while it reached to zero by 6th cycle when ethanol was used as an acyl acceptor. PMID:16822671

  3. Distribution and organoleptic impact of ethyl 2-methylbutanoate enantiomers in wine.

    PubMed

    Lytra, Georgia; Tempere, Sophie; de Revel, Gilles; Barbe, Jean-Christophe

    2014-06-01

    The enantiomers of ethyl 2-methylbutanoate were assayed in several wines using chiral gas chromatography (β-cyclodextrin). Analyses of 37 commercial red wines from various vintages and origins revealed the almost exclusive presence of the S-enantiomeric form. The average concentration was ∼50 μg/L, but the oldest samples were found to contain higher ethyl 2-methylbutanoate levels than the youngest wines. The olfactory threshold of a racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate (50:50, m/m) in dilute alcohol solution was 2.60 μg/L, almost twice that of the S-form, which was 1.53 μg/L. Ethyl (2S)-2-methylbutanoate and the racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate had different aromatic nuances: the former was mainly defined by fruity descriptors, such as green apple (Granny Smith) and strawberry, whereas the latter had an unspecific, caustic, fruity, solvent odor. Sensory analysis revealed an enhancing effect of ethyl (2S)-2-methylbutanoate on the perception of fruity aromas in the matrices studied: the "olfactory threshold" of the fruity pool, consisting of esters found in red wines, in dilute alcohol solution alone was higher than that of the same mixture supplemented with 50 μg/L ethyl (2S)-2-methylbutanoate. The sensory profiles of these aromatic reconstitutions highlighted the contribution of ethyl (2S)-2-methylbutanoate to black-berry-fruit descriptors. PMID:24844693

  4. Halogenated silanes, radicals, and cations

    NASA Astrophysics Data System (ADS)

    Wang, Liming; He, Yi-Liang

    2008-09-01

    Quantum chemistry study has been carried out on the structure and energetics of halogenated silanes, radicals, and cations (SiHxXy0,+1, X = F, Cl, Br; x + y = 1-4). The geometries are optimized at B3LYP/6-31+G(2df,p) level. The adiabatic ionization energiess (IEas), relative energetics of cations, proton affinities (PAs) of silanes, and the enthalpies of formation are predicted using G3(CC) model chemistry. Non-classical ion complex structures are found for hydrogenated cations and transition states connecting classical and non-classical structures are also located. The most stable cations for silylene and silyl radicals have their classical divalent and trivalent structures, and those for silanes have non-classical structures except for SiH3Br+ and SiH2Br2+. The non-classical structures for halosilane cations imply difficulty in experimentally measurement of the adiabatic ionization energies using photoionization or photoelectron studies. For SiH3X, SiH2X2, and SiHX3, the G3(CC) adiabatic IEas to classical ionic structures closest to their neutrals agree better with the photoelectron spectroscopic measurements. The transition states between classical and non-classical structures also hamper the photoionization determination of the appearance energies for silylene cations from silanes. The G3(CC) results for SiHx0,+1 agree excellently with the photoionization mass spectrometric study, and the results for fluorinated and chlorinated species also agree with the previous theoretical predictions at correlation levels from BAC-MP4 to CCSD(T)/CBS. The predicted enthalpy differences between SiH2Cl+, SiHCl2+, and SiCl3+ are also in accordance with previous kinetics study. The G3(CC) results show large discrepancies to the collision-induced charge transfer and/or dissociation reactions involving SiFx+ and SiClx+ ions, for which the G3(CC) enthalpies of formation are also significantly differed from the previous theoretical predictions, especially on SiFx+ (x = 2-4). The G3

  5. Pilot study of radical hysterectomy versus radical trachelectomy on sexual distress.

    PubMed

    Brotto, Lori A; Smith, Kelly B; Breckon, Erin; Plante, Marie

    2013-01-01

    Radical trachelectomy, which leaves the uterus intact, has emerged as a desirable surgical option for eligible women with early-stage cervical cancer who wish to preserve fertility. The available data suggest excellent obstetrical outcomes with radical trachelectomy, and no differences in sexual responding between radical trachelectomy and radical hysterectomy. There is a need to examine the effect of radical hysterectomy on sexual distress given that it is distinct from sexual function. Participants were 34 women diagnosed with early-stage cervical cancer. The authors report 1-month postsurgery data for 29 women (radical hysterectomy group: n = 17, M age = 41.8 years; radical trachelectomy group: n = 12, M age = 31.8 years), and 6-month follow-up data on 26 women. Whereas both groups experienced an increase in sex-related distress immediately after surgery, distress continued to increase 6 months after surgery for the radical hysterectomy group but decreased in the radical trachelectomy group. There were no between-group differences in mood, anxiety, or general measures of health. The decrease in sex-related distress in the radical trachelectomy but not in the radical hysterectomy group suggests that the preservation of fertility may have attenuated sex-related distress. Care providers should counsel women exploring surgical options for cervical cancer about potential sex distress-related sequelae. PMID:23656625

  6. Radiolytic generation of radical cations in xenon matrices. Tetramethylcyclopropane radical cation and its transformations

    SciTech Connect

    Qin, X.Z.; Trifunac, A.D. )

    1990-04-05

    Radiolytic generation of radical cations in xenon matrices containing electron scavengers is illustrated by studying the 1,1,2,2-tetramethylcyclopropane radical cation. Dilute and concentrated solutions of tetramethylcyclopropane in xenon without electron scavengers and neat tetramethylcyclopropane yielded neutral radicals upon {gamma}-irradiation. Speculation on the mechanisms of radical formation is presented. The radical species observed in the {gamma}-irradiation of neat tetramethylcyclopropane appears to be identical with the paramagnetic species observed in CF{sub 2}ClCFCl{sub 2} above 120 K, suggesting that a neutral radical rather than the ring-opened distonic radical cation is observed in the CF{sub 2}ClCFCl{sub 2} matrix.

  7. Synthesis of zwitterionic polymer-based amphiphilic triblock copolymers by atom transfer radical polymerization for production of extremely stable nanoemlusions

    NASA Astrophysics Data System (ADS)

    Lee, Jin Yong; Kim, Ji Eun; Kim, Jin Woong

    2015-03-01

    In fields of soft matter, there have been growing interests in utilizing amphiphilic block copolymers due to their intriguing properties, such as surface activity as well as self-assembly. In this work, we synthesize a series of poly (2-(methacryloyloxy) ethyl phosphorylcholine)- b-poly (ɛ-caprolactone)- b-poly (2-(methacryloyloxy) ethyl phosphorylcholine) (PMPC- b-PCL- b-PMPC) triblock copolymers by using atom transfer radical polymerization (ATRP). We have a particular interest in using poly (2-(methacryloyloxy) ethyl phosphorylcholine) (PMPC) as a hydrophilic block, since it can have both electrostatic repulsion and steric repulsion in complex fluid systems. Assembling them at the oil-water interface by using the phase inversion method enables production of highly stable nanoemulsions. From the analyses of the crystallography and self-assembly behavior, we have found that the triblock copolymers assemble to form a flexible but tough molecular thin film at the interface, which is essential for the remarkable improvement in the emulsion stability.

  8. Characteristics of Radical Reactions, Spin Rules, and a Suggestion for the Consistent Use of a Dot on Radical Species

    ERIC Educational Resources Information Center

    Wojnarovits, Laszlo

    2011-01-01

    In many chemical reactions, reactive radicals have been shown to be transient intermediates. The free radical character of a chemical species is often, but not always, indicated by adding a superscript dot to the chemical formula. A consistent use of this radical symbol on all species that have radical character is suggested. Free radicals have a…

  9. Crystal structure of (eth­oxy­ethyl­idene)di­methyl­aza­nium ethyl sulfate

    PubMed Central

    Tiritiris, Ioannis; Saur, Stefan; Kantlehner, Willi

    2015-01-01

    In the title salt, C6H14NO+·C2H5SO4 −, the C—N bond lengths in the cation are 1.2981 (14), 1.4658 (14) and 1.4707 (15) Å, indicating double- and single-bond character, respectively. The C—O bond length of 1.3157 (13) Å shows double-bond character, indicating charge delocalization within the NCO plane of the iminium ion. In the crystal, C—H⋯O hydrogen bonds between H atoms of the cations and O atoms of neighbouring ethyl sulfate anions are present, generating a three-dimensional network. PMID:26870525

  10. Studies on cytotoxic, hydroxyl radical scavenging and topoisomerase inhibitory activities of extracts of Tabernaemontana divaricata (L.) R.Br. ex Roem. and Schult.

    PubMed

    Thind, Tarunpreet Singh; Agrawal, Satyam Kumar; Saxena, A K; Arora, Saroj

    2008-08-01

    In the present investigation, the cytotoxic, hydroxyl radical scavenging and topoisomerase inhibition activities of Tabernaemontana divaricata (Apocynaceae) were evaluated. The extracts from leaves of the plant were prepared with different solvents viz. chloroform, methanol, ethyl acetate and hexane. In, in vitro cytotoxicity assay, with cell lines viz HCT-15 (Colon), HT-29 (Colon), 502713 (Colon), MCF-7 (Breast), PC- 3 (Prostrate), it was observed that the ethyl acetate extract was effective against only one colon cell line (502713) at the lowest dose i.e. 10 micro g/ml, whereas the chloroform extract was effective against all the three colon cancer cell lines, at 30 microg/ ml. In order to evaluate the mechanism of cytotoxicity of these extracts, they were assessed for their ability to scavenge hydroxyl radicals in plasmid nicking assay with pBR322. It was observed that all the extracts effectively inhibited the unwinding of supercoiled DNA except hexane extract, which showed the least effect. Since the expression of topo enzymes is linked with cell proliferation so the extracts were also checked for topo I and topo II inhibitory activities. It was noticed that ethyl acetate extract selectively showed inhibition of topo II in topoisomerase II relaxation assay. PMID:18577413

  11. Urine tested positive for ethyl glucuronide and ethyl sulphate after the consumption of "non-alcoholic" beer.

    PubMed

    Thierauf, Annette; Gnann, Heike; Wohlfarth, Ariane; Auwärter, Volker; Perdekamp, Markus Grosse; Buttler, Klaus-Juergen; Wurst, Friedrich M; Weinmann, Wolfgang

    2010-10-10

    In abstinence maintenance programs, for reissuing the driving licence and in workplace monitoring programs abstinence from ethanol and its proof are demanded. Various monitoring programs that mainly use ethyl glucuronide (EtG) as alcohol consumption marker have been established. To abstain from ethanol, but not from the taste of alcoholic beverages, in particular non-alcoholic beer has become more and more popular. In Germany, these "alcohol-free" beverages may still have an ethanol content of up to 0.5vol.% without the duty of declaration. Due to severe negative consequences resulting from positive EtG tests, a drinking experiment with 2.5L of non-alcoholic beer per person was performed to address the question of measurable concentrations of the direct metabolites EtG and EtS (ethyl sulphate) in urine and blood. Both alcohol consumption markers - determined by LC-MS/MS - were found in high concentrations: maximum concentrations in urine found in three volunteers were EtG 0.30-0.87mg/L and EtS 0.04-0.07mg/L, i.e., above the often applied cut-off value for the proof of abstinence of 0.1mg EtG/L. In the urine samples of one further volunteer, EtG and EtS concentrations cumulated over-night and reached up to 14.1mg/L EtG and 16.1mg/L EtS in the next morning's urine. Ethanol concentrations in blood and urine samples were negative (determined by HS-GC-FID and by an ADH-based method). PMID:20457499

  12. Practical use of ethyl glucuronide and ethyl sulfate in postmortem cases as markers of antemortem alcohol ingestion.

    PubMed

    Høiseth, Gudrun; Karinen, Ritva; Christophersen, Asbjørg; Mørland, Jørg

    2010-03-01

    In postmortem toxicology, it could be difficult to determine whether a positive blood ethanol concentration reflects antemortem ingestion or postmortem synthesis of alcohol. Measurement of the nonoxidative ethanol metabolite ethyl glucuronide (EtG) has been suggested as a marker of antemortem ingestion of alcohol, but EtG might degrade postmortem which could make interpretation difficult. So far, the published articles concern EtG only. Another nonoxidative metabolite, ethyl sulfate (EtS), which is more stable, has therefore been included in this study. We present a material of 36 deaths where postmortem formation of ethanol was suspected and where both EtG and EtS were measured in blood and urine to assist the interpretation. In 19 cases, EtG and EtS were positive in the body fluids analyzed. The median concentration of EtG and EtS in blood was 0.4 (range 0.1-23.2) and 0.9 mg/L (range 0.04-7.9), respectively. The median concentration of EtG and EtS in urine was 35.9 (range 1.0-182) and 8.5 mg/L (range 0.3-99), respectively. In another 16 cases, there was no trace of EtG or EtS in the specimens analyzed. In one case, there was inconsistency between the results of EtG and EtS; they were both positive in urine, while only EtS was positive in blood. This study showed that, out of 36 cases, antemortem ingestion of alcohol was very likely in 19 and unlikely in 16, according to EtG and EtS results. In the last case, the interpretation was more difficult. One possible explanation would be postmortem degradation of EtG in blood. PMID:19937334

  13. Atom Transfer Radical Copolymerization of Gradient Copolymers of HEMA/DMAEMA with Arbitrary Composition Profiles

    NASA Astrophysics Data System (ADS)

    Gallow, Keith; Loo, Yueh-Lin

    2009-03-01

    Gradient copolymers represent a new class of statistical copolymers where a non-uniform composition profile is controllably introduced along the length of the polymer chain. Gradient copolymers have thermal and mechanical properties that are different from random or block copolymers having the same average composition. Due to synthetic limitations, however, the introduction of arbitrary composition profiles remains challenging. Here, we demonstrate the ability to controllably introduce arbitrary composition profiles along copolymers of 2-hydroxyethyl methacrylate (HEMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) by atom transfer radical copolymerization in a semi-batch reactor. Using gas chromatography to monitor monomer consumption, we have constructed a kinetic model which we use as a basis to synthesize copolymers with linear and parabolic composition profiles. The overall DMAEMA content and molecular weight of these gradient copolymers were determined using nuclear magnetic resonance spectroscopy and size exclusion chromatography, respectively, and both show good agreement with our model's predictions.

  14. [Preparation of a novel polymer monolith using atom transfer radical polymerization method for solid phase extraction].

    PubMed

    Shen, Ying; Qi, Li; Qiao, Juan; Mao, Lanqun; Chen, Yi

    2013-04-01

    In this study, a novel polymer monolith based solid phase extraction (SPE) material has been prepared by two-step atom transfer radical polymerization (ATRP) method. Firstly, employing ethylene glycol dimethacrylate (EDMA) as a cross-linker, a polymer monolith filled in a filter head has been in-situ prepared quickly under mild conditions. Then, the activators generated by electron transfer ATRP (ARGET ATRP) was used for the modification of poly(2-(dimethylamino)ethyl-methacrylate) (PDMAEMA) on the monolithic surface. Finally, this synthesized monolith for SPE was successfully applied in the extraction and enrichment of steroids. The results revealed that ATRP can be developed as a facile and effective method with mild reaction conditions for monolith construction and has the potential for preparing monolith in diverse devices. PMID:23898628

  15. Kinetics of Propargyl Radical Dissociation.

    PubMed

    Klippenstein, Stephen J; Miller, James A; Jasper, Ahren W

    2015-07-16

    Due to the prominent role of the propargyl radical for hydrocarbon growth within combustion environments, it is important to understand the kinetics of its formation and loss. The ab initio transition state theory-based master equation method is used to obtain theoretical kinetic predictions for the temperature and pressure dependence of the thermal decomposition of propargyl, which may be its primary loss channel under some conditions. The potential energy surface for the decomposition of propargyl is first mapped at a high level of theory with a combination of coupled cluster and multireference perturbation calculations. Variational transition state theory is then used to predict the microcanonical rate coefficients, which are subsequently implemented within the multiple-well multiple-channel master equation. A variety of energy transfer parameters are considered, and the sensitivity of the thermal rate predictions to these parameters is explored. The predictions for the thermal decomposition rate coefficient are found to be in good agreement with the limited experimental data. Modified Arrhenius representations of the rate constants are reported for utility in combustion modeling. PMID:25871530

  16. Essential Oil from Flowers and Leaves of Elaeagnus Angustifolia (Elaeagnaceae): Composition, Radical Scavenging and General Toxicity Activities

    PubMed Central

    Torbati, Mohammadali; Asnaashari, Solmaz; Heshmati Afshar, Fariba

    2016-01-01

    Purpose: The aim of this work was to identify the chemical composition of the essential oils obtained from the flowers and leaves of Elaeagnus angostifolia (Elaeagnaceae) along with evaluate the radical scavenging and general toxicity activities. Methods: A combination of GC-MS and GC-FID were utilized for analyzing the chemical profile of the essential oils extracted by hydro-distillation from the leaves and flowers of E. angustifolia. The essential oils were subjected to general toxicity and radical scavenging assays using brine shrimp lethality test and DPPH method, respectively. Results: In total, 53 and 25 components were identified and quantified in the essential oils of flowers and leaves, accounting for 96.59% and 98.97% of the oil, respectively. The both oils were observed to be rich in ester compounds. The most abundant components of the oil from flowers were E-ethyl cinnamate (60.00%), hexahydrofarnesyl acetone (9.99%), palmitic acid (5.20%) and phytol (3.29%). The major constituents of the oil from leaves were E-ethyl cinnamate (37.27%), phytol (12.08%), nonanal (10.74%) and Z-3-hexenyl benzoate (7.65%). Both oils showed moderate activity in DPPH assay; however, they exhibited potent tocixity in brine shrimp lethality test. Conclusion: The remarkable toxicity effects of the oils are worthy to further investigation to find the probable mechanisms of action accountable for the noticeable toxic effect of these essential oils. PMID:27478777

  17. Chemical composition, anti-inflammatory, molluscicidal and free-radical scavenging activities of the leaves of Ficus radicans 'Variegata' (Moraceae).

    PubMed

    Naressi, Maria Augusta; Ribeiro, Marcos Alessandro dos Santos; Bersani-Amado, Ciomar Aparecida; Zamuner, Maria Lucilia M; Costa, Willian Ferreira da; Tanaka, Clara M Abe; Sarragiotto, Maria Helena

    2012-01-01

    The methanol crude extract of the leaves of Ficus radicans Roxb. 'Variegata' (Moraceae) and the n-hexane, ethyl acetate and aqueous methanol fractions resulting from its fractionation were evaluated for their anti-inflammatory, molluscicidal and free-radical scavenging activities. The crude extract and fractions exhibited significant inhibition of inflammation in both croton oil (CO)-induced ear oedema in mice (p<0.001) and carrageenan-induced rat paw oedema models (p<0.01). The molluscicidal assay against Biomphalaria glabrata showed a weak activity for the n-hexane fraction (DL(50)= 400 µg mL(-1)). A moderated 1,1-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity was observed for the ethyl acetate fraction (IC(50)= 66.2 µg mL(-1)). Fractionation of the extracts through chromatographic methods afforded the coumarins 7-methoxycoumarin, 7-hydroxy-6-methoxycoumarin and methoxy-3,4-dihydrocoumarin, the steroids β-sitosterol and β-sitosterol 3-O-β-glucopyranoside, as well as a cinnamic acid derivative and a flavonoid identified as trans-4-methoxy-2-β-D-glucopyranosyloxy cinnamic acid and quercetin 3-O-β-D-xylopyranosyl-(1 → 2)-α-L-rhamnopyranoside, respectively. The compounds were identified on the basis of their NMR spectral data and comparison with those previously reported in the literature. PMID:21424983

  18. Enhanced DPPH radical scavenging activity and DNA protection effect of litchi pericarp extract by Aspergillus awamori bioconversion

    PubMed Central

    2012-01-01

    Background Litchi (Litchi chinensis Sonn.) pericarp is a major byproduct which contains a significant amount of polyphenol. This study was designed to biotransformation litchi pericarp extract (LPE) by Aspergillus awamori to produce more bioactive compounds with stronger antioxidant activities. Results The study exhibited that the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities significantly (p < 0.05) increased from 15.53% to 18.23% in the water-extracted fraction and from 25.41% to 36.82% in the ethyl acetate-extracted fraction. Application of DNA cleavage assay further demonstrated the enhanced protection effect of the fermented phenolics on DNA damage. It is also noted that the water-extracted fraction of the fermented LPE possessed a much stronger capacity than the ethyl acetate-extracted fraction to prevent from damage of supercoiled DNA. Interestingly, it was found that some new compounds such as catechin and quercetin appeared after of A. awamori fermentation of LPE, which could account for the enhanced antioxidant activity. Conclusion The DPPH radical scavenging activity and DNA protection effect of LPE were increased by Aspergillus awamori bioconversion while some compounds responsible for the enhanced antioxidant activity were identified. This study provided an effective way of utilizing fruit pericarp as a readily accessible source of the natural antioxidants in food industry and, thus, extended the application area such as fruit by-products. PMID:23016522

  19. Ethyl cellulose amphiphilic graft copolymers with LCST-UCST transition: Opposite self-assembly behavior, hydrophilic-hydrophobic surface and tunable crystalline morphologies.

    PubMed

    Yuan, Hua; Chi, Hai; Yuan, Weizhong

    2016-08-20

    Novel and well-defined graft copolymer with block copolymer side chain, ethyl cellulose-graft-(poly(ε-caprolactone)-block-poly(N,N-dimethylaminoethylmeth acrylate)) (EC-g-(PCL-b-PDMAEMA)) with a lower critical solution temperature (LCST) was successfully synthesized via the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). EC-g-(PCL-b-PDMAEMA) copolymers with various PCL-b-PDMAEMA block lengths were obtained by adjusting the molar ratios of the N,N-dimethylaminoethyl methacrylate monomer to ε-caprolactone. The EC-g-(PCL-b-PDMAPS) with an upper critical solution temperature (UCST) was obtained via facile quaternization reaction of PDMAEMA with 1,3-propane sultone. EC-g-(PCL-b-PDMAEMA) and EC-g-(PCL-b-PDMAPS) micelle solutions showed opposite thermoresponsiviness and hydrophilic-hydrophobic surface. Moreover, the tunable crystalline morphologies could be obtained from these graft copolymers through changing the polymer structure and PDMAEMA contents. PMID:27178932

  20. Preparation and optical properties of CdS nanoparticles dispersed in poly(2-(dimethylamino)ethyl methacrylate-co-acrylic acid) co-polymers

    NASA Astrophysics Data System (ADS)

    Trandafilović, L. V.; Djoković, V.; Bibić, N.; Georges, M. K.; Radhakrishnan, T.

    2008-03-01

    CdS/poly(2-(dimethylamino)ethyl methacrylate-co-acrylic acid) nanocomposites were prepared and characterized using structural, optical and thermal methods. Co-polymers used as the matrices were synthesized by radical polymerization of the co-monomers in different mol ratios (1:1, 2:1 and 1:2, DMAEMA:acrylic acid). The presence of the nanostructured CdS was confirmed by TEM analysis as well as by the shift of the onset of the optical absorption towards lower wavelengths. XRD spectra showed the cubic crystal phase of the obtained CdS nanoparticles. TGA measurements revealed improved thermal stability of the nanocomposite with respect to pure co-polymer matrix.

  1. Poly(DL-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate): synthesis, characterization, micellization behavior in aqueous solutions, and encapsulation of the hydrophobic drug dipyridamole.

    PubMed

    Karanikolopoulos, Nikos; Zamurovic, Miljana; Pitsikalis, Marinos; Hadjichristidis, Nikos

    2010-02-01

    We synthesized a series of well-defined poly(dl-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate) (PDLLA-b-PDMAEMA) amphiphilic diblock copolymers by employing a three-step procedure: (a) ring-opening polymerization (ROP) of dl-lactide using n-decanol and stannous octoate, Sn(Oct)(2), as the initiating system, (b) reaction of the PDLLA hydroxyl end groups with bromoisobutyryl bromide, and (c) atom transfer radical polymerization, ATRP, of DMAEMA with the newly created bromoisobutyryl initiating site. The aggregation behavior of the prepared block copolymers was investigated by dynamic light scattering and zeta potential measurements at 25 degrees C in aqueous solutions of different pH values. The hydrophobic drug dipyridamole was efficiently incorporated into the copolymer aggregates in aqueous solutions of pH 7.40. High partition coefficient values were determined by fluorescence spectroscopy. PMID:20041661

  2. [Acidity and interaction with superoxide anion radical of echinochrome and its structural analogs].

    PubMed

    Lebedev, A V; Ivanova, M V; Krasnovid, N I; Kol'tsova, E A

    1999-01-01

    Weak acid properties, autoxidation and interaction of natural polyhydroxy1,4-naphthoquinones (PHNQ) with superoxide anion-radical (O2-.) were studied by methods of potentiometric titration, polarography, and UV- and visible spectrophotometry. Sea urchin pigments 3-acetyl-2,6,7-trihydroxynaphthazarin (spinochrome C), 2,3,6,7-trihydroxynaphthazarin (spinochrome D), 2,3,6,7-trihydroxynaphthazarin (spinochrome E), 6-ethyl-2,3,7-trihydroxynaphthazarin (echinochrome A), synthetic 2,3-dihydroxy-6,7-dimethylnaphthazarin and 6-ethyl-2,3,7-trimethoxynaphthazarin (trimethoxyechinochrome A) were tested. Determined dissociation constants (pKi) were in the range of pH 5.3-8.5 (40% ethanol solvent). PHNQ autoxidation observrd in basic pH were inhibited by superoxide dismutase. Xanthine and xanthine oxidase was applied for O2-. generation. Interaction with O2-. led to sufficient time-dependent changing in spectra of echinochrome A, spinochromes D and E. There was weak O2-. influence on spinochrome C spectrum and no changing in trimethoxyechinochrome A spectrum. The spectra, that were transforming during time of reaction, contained pronounced isobestic point. It means formation the single reaction product. We proposed formation of 1,2,3,4-tetraketones from 2,3,5,8-tetrahydroxy-1,4-naphthoquinones (echinochrome A, spinochromes D and E) due to O2-.-induced oxidation of their OH-groups in 2 and 3 positions. Reaction constants were determined by competition method using nitro blue tetrazolium (NBT). The reaction constants were about 10(4)-10(5) M-1s-1. They were decreased in the order: echinochrome A > spinochrome D > spinochrome C > NBT > trimethoxyechinochrome A. Thus, we concluded that some of the natural PGNQ, containing hydroxyl groups in 2nd and 3rd positions, could operate as powerful superoxide anion-radical scavengers. PMID:10378300

  3. Free-radical scavengers and antioxidants from Peumus boldus Mol. ("Boldo").

    PubMed

    Schmeda-Hirschmann, G; Rodriguez, J A; Theoduloz, C; Astudillo, S L; Feresin, G E; Tapia, A

    2003-04-01

    The dry leaves of Peumus boldus (Monimiaceae) are used in infusion or decoction as a digestive and to improve hepatic complains. Preliminary assays showed free-radical scavenging activity in hot water extracts of boldo leaves, measured by the decoloration of a methanolic solution of the 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH). Assay-guided isolation led to the active compounds. Catechin proved to be the main free-radical scavenger of the extracts. Lipid peroxidation in erythrocytes was inhibited by boldo extracts and fractions at 500 microg/ml with higher effect for the ethyl acetate soluble and alkaloid fractions. The IC50 for catechin and boldine in the lipid peroxidation test were 75.6 and 12.5 microg/ml, respectively. On the basis of dry starting material the catechin content in the crude drug was 2.25% while the total alkaloid calculated as boldine was 0.06%. The activity of boldine was six times higher than catechin in the lipid peroxidation assay. However, the mean catechin:total alkaloid content ratio was 37:1. The relative concentration of alkaloids and phenolics in boldo leaves and their activity suggest that free-radical scavenging effect is mainly due to catechin and flavonoids and that antioxidant effect is mainly related with the catechin content The high catechin content of boldo leaves and its bioactivity suggest that quality control of Boldo folium has to combine the analysis of catechin as well as their characteristic aporphine alkaloids. PMID:12747739

  4. Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba)

    PubMed Central

    Yang, Seun-Ah; Jeon, Sang-Kyung; Lee, Eun-Jung; Im, Nam-Kyung; Jhee, Kwang-Hwan; Lee, Sam-Pin; Lee, In-Seon

    2009-01-01

    The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), α-pinene (2.87%), caryophyllene (2.18%), β-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and α-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC50) against DPPH radicals (2.7 ± 0.63%) was lower than ABTS radicals (8.5 ± 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity. PMID:19430614

  5. Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba).

    PubMed

    Yang, Seun-Ah; Jeon, Sang-Kyung; Lee, Eun-Jung; Im, Nam-Kyung; Jhee, Kwang-Hwan; Lee, Sam-Pin; Lee, In-Seon

    2009-05-01

    The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), alpha-pinene (2.87%), caryophyllene (2.18%), beta-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and alpha-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC(50)) against DPPH radicals (2.7 +/- 0.63%) was lower than ABTS radicals (8.5 +/- 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity. PMID:19430614

  6. 21 CFR 176.160 - Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Chromium (Cr III) complex of N-ethyl-N... Substances for Use Only as Components of Paper and Paperboard § 176.160 Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine. The chromium (Cr III) complex of N-ethyl -...

  7. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  8. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  9. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  10. 40 CFR 721.10588 - Phenol, 2-[1-[[3-(1H-imidazol-1-yl)propyl]imino]ethyl]-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenol, 2- imino]ethyl]-. 721.10588... Substances § 721.10588 Phenol, 2- imino]ethyl]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol, 2- imino]ethyl]- (PMN P-11-98; CAS No....

  11. 40 CFR 721.10588 - Phenol, 2-[1-[[3-(1H-imidazol-1-yl)propyl]imino]ethyl]-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenol, 2- imino]ethyl]-. 721.10588... Substances § 721.10588 Phenol, 2- imino]ethyl]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol, 2- imino]ethyl]- (PMN P-11-98; CAS No....

  12. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  13. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  14. Synthesis and Self-Aggregation of Poly(2-ethyl-2-oxazoline)-Based Photocleavable Block Copolymer: Micelle, Compound Micelle, Reverse Micelle, and Dye Encapsulation/Release.

    PubMed

    Jana, Somdeb; Saha, Anupam; Paira, Tapas K; Mandal, Tarun K

    2016-02-01

    We report on the synthesis of photocleavable poly(2-ethyl-2-oxazoline)-block-poly(2-nitrobenzyl acrylate) (PEtOx-b-PNBA) block copolymers (BCPs) with varying compositions via combination of microwave-assisted cationic ring-opening polymerization (CROP) and atom transfer radical polymerization (ATRP) using α-bromoisobutyryl bromide as an orthogonal initiator. The amphiphilic nature of this BCP causes them to self-assemble into primary micelles in THF/H2O, which further undergo secondary aggregation into nanostructured compound micelles as established through DLS, FESEM, and TEM. Upon UV irradiation (λ = 350 nm), the photocleavage of the PNBA block of the PEtOx-b-PNBA BCP takes place, and that leads to the formation of the doubly hydrophilic poly(2-ethyl-2-oxazoline)-b-poly(acrylic acid) (PEtOx-b-PAA) BCP causing the rupture of compound micelles as confirmed by spectroscopic and microscopic techniques. Encapsulation of a model hydrophobic guest molecule, nile red (NR), into the photocleavable BCP micellar core in aqueous solution and its UV-induced release is also investigated by fluorescence emission measurements. PEtOx-b-PNBA BCP amphiphiles are also shown to self-assemble into spherical nanostructures (∼90 nm) in dichloromethane as established by DLS and TEM analysis. These are referred to as reverse micelles and are able to encapsulate anionic hydrophilic dye, Eosin B, and facilitate its solubilization in organic media. PMID:26735171

  15. Radical scavenging activities of niacin-related compounds.

    PubMed

    Ogata, Shin; Takeuchi, Masayo; Teradaira, Shin; Yamamoto, Naokuni; Iwata, Keiko; Okumura, Katsuzumi; Taguchi, Hiroshi

    2002-03-01

    We investigated whether niacin-related compounds had radical-scavenging activity by electron spin resonance methods. Many compounds, but not trigonelline, had radical-scavenging activity against hydroxyl radicals. However, for the nitric oxide radical and 1,1-diphenyl-2-picrylhydrazyl radical, only nicotinic acid hydrazide and isonicotinic acid hydrazide had scavenging activities. These results suggest that the moiety of hydrazide might have an important role in scavenging abilities of various radicals. PMID:12005062

  16. Competition of charge- versus radical-directed fragmentation of gas-phase protonated cysteine sulfinyl radicals.

    PubMed

    Love, Chasity B; Tan, Lei; Francisco, Joseph S; Xia, Yu

    2013-04-24

    The fragmentation behavior of various cysteine sulfinyl ions (intact, N-acetylated, and O-methylated), new members of the gas-phase amino acid radical ion family, was investigated by low-energy collision-induced dissociation (CID). The dominant fragmentation channel for the protonated cysteine sulfinyl radicals ((SO•)Cys) was the radical-directed Cα-Cβ homolytic cleavage, resulting in the formation of glycyl radical ions and loss of CH2SO. This channel, however, was not observed for protonated N-acetylated cysteine sulfinyl radicals (Ac-(SO•)Cys); instead, charge-directed H2O loss followed immediately by SH loss prevailed. Counterintuitively, the H2O loss did not derive from the carboxyl group but involved the sulfinyl oxygen, a proton, and a Cβ hydrogen atom. Theoretical calculations suggested that N-acetylation significantly increases the barrier (~14 kcal mol(-1)) for the radical-directed fragmentation channel because of its reduced capability to stabilize the thus-formed glycyl radical ions via the captodative effect. N-Acetylation also assists in moving the proton to the sulfinyl site, which reduces the barrier for H2O loss. Our studies demonstrate that for cysteine sulfinyl radical ions, the stability of the product ions (glycyl radical ions) and the location of the charge (proton) can significantly modulate the competition between radical- and charge-directed fragmentation. PMID:23527556

  17. Expanding Radical SAM Chemistry by Using Radical Addition Reactions and SAM Analogues.

    PubMed

    Ji, Xinjian; Li, Yongzhen; Xie, Liqi; Lu, Haojie; Ding, Wei; Zhang, Qi

    2016-09-19

    Radical S-adenosyl-l-methionine (SAM) enzymes utilize a [4Fe-4S] cluster to bind SAM and reductively cleave its carbon-sulfur bond to produce a highly reactive 5'-deoxyadenosyl (dAdo) radical. In almost all cases, the dAdo radical abstracts a hydrogen atom from the substrates or from enzymes, thereby initiating a highly diverse array of reactions. Herein, we report a change of the dAdo radical-based chemistry from hydrogen abstraction to radical addition in the reaction of the radical SAM enzyme NosL. This change was achieved by using a substrate analogue containing an olefin moiety. We also showed that two SAM analogues containing different nucleoside functionalities initiate the radical-based reactions with high efficiencies. The radical adduct with the olefin produced in the reaction was found to undergo two divergent reactions, and the mechanistic insights into this process were investigated in detail. Our study demonstrates a promising strategy in expanding radical SAM chemistry, providing an effective way to access nucleoside-containing compounds by using radical SAM-dependent reactions. PMID:27573794

  18. Mechanism of quizalofop-ethyl selectivity in monocotyledonous and dicotyledonous species

    SciTech Connect

    Ruizzo, M.A.

    1986-01-01

    Cucumber (Cucumis sativus L.) susceptibility to quizalofop-ethyl herbicide was investigated under field and greenhouse conditions. Yield of cucumber cultivars was significantly reduced under field conditions with a single or repeat application of the ethyl ester of quizalofop at 0.14 or 0.28 kg ai/ha. Under greenhouse conditions, quialofop-ethyl significantly suppressed cucumber plant fresh weight with or without the presence of an adjuvant. Enhancement of herbicide activity was directly related to concentration of adjuvant. Microliter droplet application of quizalofop-ethyl at a 10/sup -3/ M concentration, inhibited the relative growth (RGR) and net assimilation rate (NAR) of the treated cucumber leaf 45% and 52%, respectively. Expression of herbicidal injury was localized on the treated leaf with no visible symptoms observed on adjacent leaves. Radiolabeled /sup 14/C-quizalofop-ethyl was applied to leaves of cucumber and corn (Zea mays L.) to compare translocation patterns between two susceptible plant species and relate this information to the observed selectivity of the herbicide. Cucumber autoradiographs showed minimal translocation of /sup 14/C-quizalofop-ethyl 192 hours after treatment. In contrast, corn autoradiographs showed both apoplastic and symplastic transport of quizalofop-ethyl 3 and 24 hours after treatment. Quantification of /sup 14/C in cucumber revealed 96% of absorbed /sup 14/C was confined to the treated leaf after 192h of exposure.

  19. [Study on vibrational spectra of ethyl hexanoate molecule].

    PubMed

    Cai, Zhi-peng; Du, Ya-bing; Zhang, Ling; Li, Peng-wei; Jia, Ting-jian; Mo, Yu-jun

    2008-09-01

    The vibrational spectra of ethyl hexanoate were calculated by the density functional theory (DFT) with B3LYP complex function, diffuse function and polarization function added to heavy atoms and light atoms. On the base of this, the normal Raman spectrum (NRS) and the infrared spectrum (IR) were assigned in detail in the present paper. Comparing the calculated results with the experimental data, the calculated results are in good agreement with the experimental results. The comparison of the experimental Raman and infrared spectra shows that in the experimental Raman spectrum, the strongest bands appear at the frequencies of 2600-3100 cm(-1), while the strongest band is not 1734 cm(-1) but 1444 cm(-1) at the frequencies of 400-2000 cm(-1). The band 1734 cm(-1) attributed to the C=O stretch vibration is the distinctive mark of organic ester compounds, and the band 1444 cm(-1) is related to the symmetric and anti-symmetric scissors vibration of C-H. In the experimental infrared spectrum, the strongest vibrational band is 1739 cm(-1), which is related to C=O stretch vibration; At the frequencies of 400-2000 cm(-1), the relative intensity of the infrared spectrum is distinctively stronger than that of the Raman spectrum, but the relative intensity of infrared spectrum is weaker than that of the Raman spectrum at the frequencies of 2600-3100 cm(-1). In the frequencies of 2600-2800 cm(-1), the vibrational bands 2762 and 2732 cm(-1) do not appear in the experimental spectra, which may originate from two reasons: (1) the weak interaction of molecules. Also, the relative intensity of these vibrational bands is very weak in the experimental spectra, and this may testify that the interaction of molecules is rather weak; (2) the vibrational bands may belong to second order vibrational mode at the frequencies of 2600-2800 cm(-1). The relative intensity of infrared bands is weaker than that of the Raman bands at the frequencies of 2600-2800 cm(-1). At the end, the stronger bands

  20. Replication across Regioisomeric Ethylated Thymidine Lesions by Purified DNA Polymerases

    PubMed Central

    Andersen, Nisana; Wang, Pengcheng; Wang, Yinsheng

    2013-01-01

    Causal links exist between smoking cigarettes and cancer development. Some genotoxic agents in cigarette smoke are capable of alkylating nucleobases in DNA and higher levels of ethylated DNA lesions were observed in smokers than non-smokers. In this study, we examined comprehensively how the regioisomeric O2-, N3- and O4-ethylthymidine (O2-, N3- and O4-EtdT) perturb DNA replication mediated by purified human DNA polymerases (hPol) η, κ, and ι, yeast DNA polymerase ζ (yPol ζ), and the exonuclease-free Klenow fragment (Kf−) of Escherichia coli DNA polymerase I. Our results showed that hPol η and Kf− could bypass all three lesions and generate full-length replication products, whereas hPol ι stalled after inserting a single nucleotide opposite the lesions. Bypass carried out by hPol κ and yPol ζ differed markedly amongst the three lesions: Consistent with its known capability in bypassing efficiently the minor-groove N2-substituted 2′-deoxyguanosine lesions, hPol κ was able to bypass O2-EtdT, though it experienced great difficulty in bypassing N3-EtdT and O4-EtdT; yPol ζ was only modestly blocked by O4-EtdT, but the polymerase was highly hindered by O2-EtdT and N3-EtdT. LC-MS/MS analysis of the replication products revealed that DNA synthesis opposite O4-EtdT was highly error-prone, with dGMP being preferentially inserted, while the presence of O2-EtdT and N3-EtdT in template DNA directed substantial frequencies of misincorporation of dGMP and, for hPol ι and Kf−, dTMP. Thus, our results suggested that O2-EtdT and N3-EtdT may also contribute to the AT→TA and AT→GC mutations observed in cells and tissues of animals exposed to ethylating agents. PMID:24134187

  1. Searching for trans ethyl methyl ether in Orion KL⋆

    NASA Astrophysics Data System (ADS)

    Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

    2015-10-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm-2 and ≤(1.0 ± 0.2) × 1015 cm-2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. This work was also based on observations carried out with the IRAM 30-m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Appendix A is available in electronic form at http://www.aanda.org

  2. Graft copolymers of ethyl methacrylate on waxy maize starch derivatives as novel excipients for matrix tablets: physicochemical and technological characterisation.

    PubMed

    Marinich, J A; Ferrero, C; Jiménez-Castellanos, M R

    2009-05-01

    Nowadays, graft copolymers are being used as an interesting option when developing a direct compression excipient for controlled release matrix tablets. New graft copolymers of ethyl methacrylate (EMA) on waxy maize starch (MS) and hydroxypropylstarch (MHS) were synthesised by free radical polymerization and alternatively dried in a vacuum oven (OD) or freeze-dried (FD). This paper evaluates the performance of these new macromolecules and discusses the effect of the carbohydrate nature and drying process on their physicochemical and technological properties. Grafting of EMA on the carbohydrate backbone was confirmed by IR and NMR spectroscopy, and the grafting yields revealed that graft copolymers present mainly a hydrophobic character. The graft copolymerization also leads to more amorphous materials with larger particle size and lower apparent density and water content than carbohydrates (MS, MHS). All the products show a lack of flow, except MHSEMA derivatives. MSEMA copolymers underwent much plastic flow and less elastic recovery than MHSEMA copolymers. Concerning the effect of drying method, FD derivatives were characterised by higher plastic deformation and less elasticity than OD derivatives. Tablets obtained from graft copolymers showed higher crushing strength and disintegration time than tablets obtained from raw starches. This behaviour suggests that these copolymers could be used as excipients in matrix tablets obtained by direct compression and with a potential use in controlled release. PMID:19146956

  3. Study the friction behaviour of poly[2-(dimethylamino)ethyl methacrylate] brush with AFM probes in contact mechanics

    NASA Astrophysics Data System (ADS)

    Raftari, Maryam; Zhang, Zhenyu; Leggett, Graham J.; Geoghegan, Mark

    2011-10-01

    We have studied the frictional behaviour of grafted poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) films using friction force microscopy (FFM). The films were prepared on native oxide-terminated silicon substrates using the technique of atom transfer radical polymerization (ATRP). We show that single asperity contact mechanics (Johnson-Kendall-Roberts(JKR) and Derjaguin-Muller-Toporov(DMT)) as well as a linear (Amontons) relation between applied load and frictional load depending on the pH of the FFM probe. Measurements were made using functionalized and unfunctionalized silicon nitride triangular probes. Functionalized probes included gold-coated probes, and ones coated with a self-assembled monolayer of dodecanethiol (DDT). The frictional behaviour between PDMAEMA and all tips immersed in pH from 3 to 11 are corresponded to the DMT or JKR model and are linear in pH=1, 2, and 12. These results show that contact mechanics of polyelectrolytes in water is complex and strongly dependent on the environmental pH.

  4. Induction of cell proliferation in the rat liver by the short-term administration of ethyl tertiary-butyl ether

    PubMed Central

    Kakehashi, Anna; Hagiwara, Akihiro; Imai, Norio; Wei, Min; Fukushima, Shoji; Wanibuchi, Hideki

    2015-01-01

    In the present study, in continuation of our previous experiment in order to investigate the mode of action (MOA) of ethyl tertiary-butyl ether (ETBE) hepatotumorigenicity in rats, we aimed to examine alterations in cell proliferation, that are induced by short-term administration of ETBE. F344 rats were administered ETBE at doses of 0, and 1,000 mg/kg body weight twice a day by gavage for 3, 10, 17 and 28 days. It was found that the previously observed significant increase of P450 total content and hydroxyl radical levels after 7 days of ETBE administration, and 8-OHdG formation at day 14, accompanied by accumulation of CYP2B1/2B2, CYP3A1/3A2, CYP2C6, CYP2E1 and CYP1A1 and downregulation of DNA oxoguanine glycosylase 1, was preceded by induction of cell proliferation at day 3. Furthermore, we observed an increase in regenerative cell proliferation as a result of ETBE treatment at day 28, followed by induction of cell cycle arrest and apoptosis by day 14. These results indicated that short-term administration of ETBE led to a significant early increase in cell proliferation activity associated with induction of oxidative stress, and to a regenerative cell proliferation as an adaptive response, which could contribute to the hepatotumorigenicity of ETBE in rats. PMID:26023258

  5. Surface Modification of Polypropylene Microporous Membrane by Atmospheric-Pressure Plasma Immobilization of N,N-dimethylamino Ethyl Methacrylate

    NASA Astrophysics Data System (ADS)

    Zhong, Shaofeng

    2010-10-01

    Surface modification of polypropylene microporous membrane (PPMM) was performed by atmospheric pressure dielectric barrier discharge plasma immobilization of N,N-dimethylamino ethyl methacrylate (DMAEMA). Structural and morphological changes on the membrane surface were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (FT-IR/ATR), X-ray photoelectron spectroscope (XPS) and field emission scanning electron microscopy (FE-SEM). Water contact angles of the membrane surfaces were also measured by the sessile drop method. Results reveal that both the plasma-treating conditions and the adsorbed DMAEMA amount have remarkable effects on the immobilization degree of DMAEMA. Peroxide determination by 1,1-diphenyl-2-picrvlhydrazyl (DPPH) method verifies the exsistence of radicals induced by plasma, which activize the immobilization reaction. Pure water contact angle on the membrane surface decreased with the increase of DMAEMA immobilization degree, which indicates an enhanced hydrophilicity for the modified membranes. The effects of immobilization degrees on pure water fluxes were also measured. It is shown that pure water fluxes first increased with immobilization degree and then decreased. Finally, permeation of bovine serum albumin (BSA) and lysozyme solution were measured to evaluate the antifouling property of the DMAEMA-modified membranes, from which it is shown that both hydrophilicity and electrostatic repulsion are beneficial for membrane antifouling.

  6. Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium for detection of alcohol abuse during pregnancy: Correlation study between both biomarkers.

    PubMed

    Cabarcos, Pamela; Tabernero, María Jesús; Otero, José Luís; Míguez, Martha; Bermejo, Ana María; Martello, Simona; De Giovanni, Nadia; Chiarotti, Marcello

    2014-11-01

    This article presents results from 47 meconium samples, which were analyzed for fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for detection of gestational alcohol consumption. A validated microwave assisted extraction (MAE) method in combination with GC-MS developed in the Institute of Forensic Science (Santiago de Compostela) was used for FAEE and the cumulative concentration of ethyl myristate, ethyl palmitate and ethyl stearate with a cut-off of 600ng/g was applied for interpretation. A simple method for identification and quantification of EtG has been evaluated by ultrasonication followed solid phase extraction (SPE). Successful validation parameters were obtained for both biochemical markers of alcohol intake. FAEE and EtG concentrations in meconium ranged between values lower than LOD and 32,892ng/g or 218ng/g respectively. We have analyzed FAEE and EtG in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. Certain agreement between the two biomarkers was found as they are both a very specific alcohol markers, making it a useful analysis for confirmation. PMID:25137651

  7. Reactions of Ethyl Groups on a Model Chromia Surface: Ethyl Chloride on Stoichiometric Alpha-Cr2O3(1012)

    SciTech Connect

    Brooks, J.; Ma, Q; Cox, D

    2009-01-01

    The reaction of CH3CH2Cl over the nearly-stoichiometric ?-Cr2O3 (1 0 View the MathML source 2) surface yields gas phase CH2double bond; length as m-dashCH2, CH3CH3, H2 and surface chlorine adatoms. The decomposition reaction is initiated via C-Cl bond cleavage to give a surface ethyl (CH3CH2-) intermediate. A rate-limiting ?-hydride elimination from the surface ethyl species produces gas phase CH2double bond; length as m-dashCH2 and surface hydrogen atoms. Two parallel competing reactions form CH3CH3, via ?-hydride addition to remaining surface ethyl species (reductive elimination), and H2, via the combination of two surface hydrogen atoms. The chlorine freed from the dissociation of CH3CH2Cl binds at the five-coordinate surface Cr3+ sites on the stoichiometric surface and inhibits the surface chemistry via simple site blocking. No surface carbon deposition is observed from the thermal reaction of ethyl chloride, suggesting that ethyl intermediates are not primary coke forming intermediates in the dehydrogenation of ethane over (1 0 View the MathML source 2) facets of ?-Cr2O3.

  8. Theoretical and kinetic study of the reaction of ethyl methyl ketone with HO2 for T = 600-1600 K. Part II: addition reaction channels.

    PubMed

    Zhou, Chong-Wen; Mendes, Jorge; Curran, Henry J

    2013-06-01

    The temperature and pressure dependence of the addition reaction of ethyl methyl ketone (EMK) with HO2 radical has been calculated using the master equation method employing conventional transition state theory estimates for the microcanonical rate coefficients in the temperature range of 600-1600 K. Geometries, frequencies, and hindrance potentials were obtained at the B3LYP/6-311G(d,p) level of theory. A modified G3(MP2,CC) method has been used to calculate accurate electronic energies for all of the species involved in the reactions. The rigid-rotor harmonic oscillator approximation has been used for all of the vibrations except for the torsional degrees of freedom which are being treated as 1D hindered rotors. Asymmetric Eckart barriers were used to model tunneling effect in a one-dimensional reaction coordinate through saddle points. Our calculated results show that the four reaction channels forming 1-buten-2-ol + HO2 radical (R5), 2-buten-2-ol + HO2 radical (R10), acetic acid + ethylene + OH radical (R13), and 2-methyl-2-oxetanol + OH radical (R15) are the dominant channels. When the temperature is below 1000 K, the reaction R15 forming the cyclic ether, 2-methyl-2-oxetanol, is dominant while the reaction R13 forming acetic acid + ethylene + OH radical becomes increasingly dominant at temperatures above 1000 K. The other two channels forming 1-buten-2-ol, 2-buten-2-ol, and HO2 radical are not dominant but are still important product channels over the whole temperature range investigated here. No pressure dependence has been found for the reaction channels forming 2-methyl-2-oxetanol + OH radical and acetic acid + ethylene + OH radical. A slightly negative pressure dependence has been found for the reaction channels producing the two butenols. Rate constants for the four important reaction channels at 1 atm (in cm(3) mol(-1) s(-1)) are k(R5) = 2.67 × 10(15) × T(-1.32)exp(-16637/T), k(R10) = 1.62 × 10(8) × T(0.57)exp(-13142/T), k(R13) = 2.29 × 10(17) × T

  9. The synthesis and purification of aromatic hydrocarbons V : 1-ethyl-3-methylbenzene

    NASA Technical Reports Server (NTRS)

    Ebersole, Earl R

    1946-01-01

    The method used for the synthesis and purification of an 8-gallon quantity of 1-ethyl-3-methylbenzene from m-creosol consists in obtaining m-methylcyclohexanone from m-creosol by hydrogenation followed by oxidation, condensation of the ketone with ethylmagnesium bromide, dehydration of the tertiary alcohol obtained, and the dehydration of the olefins to 1-ethyl-3-methylbenzene. A yield of 28 percent of the theoretical was obtained from 98 percent commercial m-creosol. The physical properties of the 1-ethyl-3-methylbenzene are compared with selected values from the literature.

  10. A Mechanochemical Switch to Control Radical Intermediates

    PubMed Central

    2015-01-01

    B12-dependent enzymes employ radical species with exceptional prowess to catalyze some of the most chemically challenging, thermodynamically unfavorable reactions. However, dealing with highly reactive intermediates is an extremely demanding task, requiring sophisticated control strategies to prevent unwanted side reactions. Using hybrid quantum mechanical/molecular mechanical simulations, we follow the full catalytic cycle of an AdoB12-dependent enzyme and present the details of a mechanism that utilizes a highly effective mechanochemical switch. When the switch is “off”, the 5′-deoxyadenosyl radical moiety is stabilized by releasing the internal strain of an enzyme-imposed conformation. Turning the switch “on,” the enzyme environment becomes the driving force to impose a distinct conformation of the 5′-deoxyadenosyl radical to avoid deleterious radical transfer. This mechanochemical switch illustrates the elaborate way in which enzymes attain selectivity of extremely chemically challenging reactions. PMID:24846280

  11. A mechanochemical switch to control radical intermediates.

    PubMed

    Brunk, Elizabeth; Kellett, Whitney F; Richards, Nigel G J; Rothlisberger, Ursula

    2014-06-17

    B₁₂-dependent enzymes employ radical species with exceptional prowess to catalyze some of the most chemically challenging, thermodynamically unfavorable reactions. However, dealing with highly reactive intermediates is an extremely demanding task, requiring sophisticated control strategies to prevent unwanted side reactions. Using hybrid quantum mechanical/molecular mechanical simulations, we follow the full catalytic cycle of an AdoB₁₂-dependent enzyme and present the details of a mechanism that utilizes a highly effective mechanochemical switch. When the switch is "off", the 5'-deoxyadenosyl radical moiety is stabilized by releasing the internal strain of an enzyme-imposed conformation. Turning the switch "on," the enzyme environment becomes the driving force to impose a distinct conformation of the 5'-deoxyadenosyl radical to avoid deleterious radical transfer. This mechanochemical switch illustrates the elaborate way in which enzymes attain selectivity of extremely chemically challenging reactions. PMID:24846280

  12. The Electronic Spectrum of the Fulvenallenyl Radical.

    PubMed

    Chakraborty, Arghya; Fulara, Jan; Maier, John P

    2016-01-01

    The fulvenallenyl radical was produced in 6 K neon matrices after mass-selective deposition of C7H5(-) and C7H5(+) generated from organic precursors in a hot cathode ion source. Absorption bands commencing at λ=401.3 nm were detected as a result of photodetachment of electrons from the deposited C7H5(-) and also by neutralization of C7H5(+) in the matrix. The absorption system is assigned to the 1 (2)B1 ←X (2)B1 transition of the fulvenallenyl radical on the basis of electronic excitation energies calculated with the MS-CASPT2 method. The vibrational excitation bands detected in the spectrum concur with the structure of the fulvenallenyl radical. Employing DFT calculations, it is found that the fulvenallenyl anion and its radical are the global minima on the potential energy surface among plausible structures of C7H5. PMID:26593635

  13. Fast beam studies of free radical photodissociation

    SciTech Connect

    Neumark, D.M.

    1993-12-01

    The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

  14. [Robotic laparoscopic radical prostatectomy: update 2008].

    PubMed

    John, H

    2008-03-01

    Radical prostatectomy aims for optimal tumor control, minimal morbidity, and best functional outcomes of urinary continence and erection. With the introduction of the robotic daVinci surgical system an impressive shift from open radical to robotic laparoscopic prostatectomy (RLP) has occurred especially in the USA. Unfortunately, initial and instrumental costs and maintenance fees of the system are still very high. Compared with the open retropubic approach, RLP has a similar short-term outcome in oncological control, potency, and urinary continence but potentially distinctly favorable benefits in blood loss, transfusion rates, and minor complications. However, RLP is still in its infancy compared to open radical prostatectomy. Inter-institutional trials with the same validated questionnaires are necessary for the future to evaluate oncological and functional results conclusively. The individual surgeon's experience with his routinely preferred technique remains the crucial key for a successful oncological and functional outcome in radical prostatectomy, whatever technology is used. PMID:18231769

  15. HETEROGENOUS PHOTOREACTION OF FORMALDEHYDE WITH HYDROXYL RADICALS

    EPA Science Inventory

    Atmospheric heterogeneous photoreactions occur between formaldehyde and hydroxyl radicals to produce formic acid. hese photoreactions not only occur in clouds, but also in other tropospheric hydrometeors such as precipitation and dew droplets. xperiments were performed by irradia...

  16. [Pulmonary toxicity of free radicals of oxygen].

    PubMed

    Housset, B; Junod, A

    1983-01-01

    Free oxygen radicals result from aerobic cellular metabolism; their toxicity is prevented by immediate degradation due to an endless variety of biochemical systems. The nature of these radicals, their cellular production as well as the defence mechanism which oppose their toxic effects are successively and briefly analysed. The potential role of these radicals in the genesis of different lung diseases is still poorly understood. However, certain toxic agents (oxygen, gas pollutants, ionising radiation, toxic products) can act as a whole or at least in part by their intermediaries. The experimental arguments in favour of this hypothesis are reviewed in passing. If the relative importance of the toxic mechanism is still imprecise, free radicals are certainly implicated in pulmonary disease and constitute a new aspect of respiratory patho-physiology. PMID:6189156

  17. Innovation Type, Radicalness, and the Adoption Process.

    ERIC Educational Resources Information Center

    Damanpour, Fariborz

    1988-01-01

    Reviews studies on the impact of organizational factors on the adoption of innovations along three dimensions (innovation type, innovation radicalness, and stages of adoption), finding considerable agreement. Proposes a research agenda for future studies. (SR)

  18. RADICALLY CONTESTED ASSERTIONS IN ECOSYSTEM MANAGEMENT

    EPA Science Inventory

    Ecosystem management is a magnet for controversy, in part because some of its formulations rest on questionable assertions that are radically contested. These assertions are important to understanding much of the conflict surrounding ecosystem management and, therrefore, deserve...

  19. Catalytic Radical Domino Reactions in Organic Synthesis

    PubMed Central

    Sebren, Leanne J.; Devery, James J.; Stephenson, Corey R.J.

    2014-01-01

    Catalytic radical-based domino reactions represent important advances in synthetic organic chemistry. Their development benefits synthesis by providing atom- and step-economical methods to complex molecules. Intricate combinations of radical, cationic, anionic, oxidative/reductive, and transition metal mechanistic steps result in cyclizations, additions, fragmentations, ring-expansions, and rearrangements. This Perspective summarizes recent developments in the field of catalytic domino processes. PMID:24587964

  20. Regioselective Radical Arylation of 3-Hydroxypyridines.

    PubMed

    Fürst, Michael C D; Bock, Leonard R; Heinrich, Markus R

    2016-07-01

    The titanium(III)-mediated radical arylation of 3-hydroxypyridines was found to proceed with high regioselectivity for the 2-position. Using aryldiazonium chlorides, which were prepared from the corresponding anilines, as aryl radical sources, a range of 3-hydroxy-2-phenylpyridines were obtained in moderate to good yields under simple reaction conditions. Reactions of ortho-carboxylic ester substituted phenyldiazonium salts directly provided tricyclic benzopyranopyridinones. PMID:27258367

  1. The stabilization energies of polyenyl radicals

    NASA Astrophysics Data System (ADS)

    Luo, Yu-Ran; Holmes, John L.

    1994-10-01

    The resonance stabilization energies, Es, of polyenyl radicals can be estimated by the equation Es( N)=-13.2+[3.95-15.8(2) -2/ n] kcal mol -1, where N is the number of C, C-π bonds in the polyenyl radicals. This correlation has been extended for predicting the weakest HC, CC and COH bond dissociation energies in vitamin A and similar compounds.

  2. Gauche Ethyl Alcohol: Laboratory Assignments and Interstellar Identification

    NASA Technical Reports Server (NTRS)

    Pearson, J. C.; Sastry, K. V. L. N.; Herbst, Eric; DeLucia, Frank C.

    1997-01-01

    Ethyl alcohol (ethanol) is known to possess a pair of closely spaced excited torsional substates (gauche+, gauche-) at an energy of approximately 57 K above the ground (trans) torsional substate. We report an extended analysis of some gauche - gauche+ Q-branch ((Delta)J = 0) transitions with a three-substate fixed frame axis method (FFAM) Hamiltonian. Our approach accounts for complex trans-gauche interactions for the first time. In addition, we are able to obtain intensities for perturbed rotational transitions, and to determine the trans to gauche+ separation to be 1185399.1 MHz. A complete ground state rotational-torsional partition function accounting for the previously neglected gauche substates is presented. Based on our analysis, a total of 14 U lines obtained towards Orion KL can now be assigned to gauche substates of ethanol. Analysis of these lines yields a rotational temperature of 223 K and a total (trans + gauche) column density of 7.0 x 10(exp 15)/sq cm. The column density is in reasonable agreement with the recent value of 2-3 x 10(exp 15)/sq cm based on observations of trans-ethanol by Ohishi et al., although there is some disparity in the rotational temperatures. Eight additional U lines in the literature are assigned to transitions of gauche ethanol.

  3. Enhanced photochemistry of ethyl chloride on Ag nanoparticles.

    PubMed

    Toker, Gil; Bespaly, Alexander; Zilberberg, Liat; Asscher, Micha

    2015-02-11

    Enhanced photodecomposition of ethyl chloride (EC) adsorbed on SiO2/Si (100) supported silver nanoparticles (Ag NPs) under ultrahigh vacuum (UHV) conditions has been studied in order to assess the potential contribution of plasmonic effects. The cross section for photodecomposition of EC and overall photoyield were found to increase with increasing photon energy regardless of the plasmon resonant wavelength and with Ag coverage without any noticeable particle size effect. The influence of EC-Ag NPs separation distance on the rate of EC decomposition was studied in order to examine potential local electric field influence on the photodissociation process. Long (∼5 nm) photoactivity decay distance has been observed which excludes local surface plasmon dominance in the photodecomposition event. These findings suggest that the alignment of excited electron energy and adsorbate affinity levels is central for efficient photochemical reactions, whereas short-range electric field enhancement by plasmon excitation on top and at the immediate vicinity of silver nanoparticles does not have any measurable effect. PMID:25555201

  4. The pharmacological actions of pempidine and its ethyl homologue

    PubMed Central

    Spinks, A.; Young, E. H. P.; Farrington, J. A.; Dunlop, D.

    1958-01-01

    Pempidine, and other highly active ganglion blocking agents of the polyalkylpiperidine series, were developed from tertiary alkylamines, themselves weakly active, on the hypothesis that high activity was conferred by the presence in the molecule of a sterically hindered secondary or tertiary nitrogen atom. Pempidine and its N-ethyl homologue (26539) resembled mecamylamine qualitatively. All three drugs blocked sympathetic and parasympathetic ganglia; this action was slow in onset and protracted. They blocked neuromuscular transmission, but only about one hundredth as powerfully as ganglionic transmission. They caused a fall in amplitude and rate of the isolated heart, and reduced coronary flow. They had local anaesthetic properties in one of four tests used. They caused tremor. All were well absorbed when administered orally. Pempidine was about twice as active as mecamylamine on ganglia, but only about one half to one quarter as toxic as judged by death, growth, induction of tremor, or cardiotoxicity. Compound 26539 was also quantitatively superior to mecamylamine in respect of these safety margins, but unlike pempidine or mecamylamine damaged the pituitary gland and testis when administered daily for several months. The mode of action of the three drugs is discussed: the results give tentative support for the hypothesis that their action is intracellular. PMID:13618559

  5. Inactivation of Bacillus atrophaeus by OH radicals

    NASA Astrophysics Data System (ADS)

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He–H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  6. Hydroxyl radical oxidation of feruloylated arabinoxylan.

    PubMed

    Bagdi, Attila; Tömösközi, Sándor; Nyström, Laura

    2016-11-01

    Feruloylated arabinoxylan (AX) has a unique capacity to form covalent gels in the presence of certain oxidizing agents. The present study demonstrates that hydroxyl radical oxidation does not provoke ferulic acid dimerization and thus oxidative gelation. We studied the hydroxyl radical mediated oxidation of an alkali-extracted AX preparation (purity: 92g/100g dry matter) that showed gel-forming capability upon peroxidase/hydrogen peroxide treatment. Hydroxyl radicals were produced with ascorbate-driven Fenton reaction and the radical formation was monitored with electron paramagnetic resonance, using a POBN/EtOH spin trapping system. Oxidation was carried out at different catalytic concentrations of iron (50 and 100μM) and at different temperatures (20°C, 50°C, and 80°C). It was demonstrated that hydroxyl radical oxidation does not provoke gel formation, but viscosity decrease in AX solution, which suggests polymer degradation. Furthermore, it was demonstrated that hydroxyl radical formation in AX solution can be initiated merely by increasing temperature. PMID:27516272

  7. Ethyl sulphate and ethyl glucuronide in vitreous humor as postmortem evidence marker for ethanol consumption prior to death.

    PubMed

    Thierauf, Annette; Kempf, Jürgen; Perdekamp, Markus Grosse; Auwärter, Volker; Gnann, Heike; Wohlfarth, Ariane; Weinmann, Wolfgang

    2011-07-15

    To clarify the circumstances of death, the degree of inebriation is of importance in many cases, but for several reasons the determination of the ethanol concentration in post-mortem samples can be challenging and the synopsis of ethanol and the direct consumption markers ethyl glucuronide (EtG) and ethyl sulphate (EtS) has proved to be useful. The use of a rather stable matrix like vitreous humor offers further advantages. The aim of this study was to determine the concentrations of ethanol and the biomarkers in the robust matrix of vitreous humor and to compare them with the respective levels in peripheral venous blood and urine. Samples of urine, blood from the femoral vein and vitreous humor were taken from 26 deceased with suspected ethanol consumption prior to death and analyzed for ethanol, EtS and EtG. In the urine samples creatinine was also determined. The personal data, the circumstances of death, the post-mortem interval and the information about ethanol consumption prior to death were recorded. EtG and EtS analysis in urine was performed by LC-ESI-MS/MS, creatinine concentration was determined using the Jaffé reaction and ethanol was detected by HS-GC-FID and by an ADH-based method. In general, the highest concentrations of the analytes were found in urine and showed statistical significance. The mean concentrations of EtG were 62.8mg/L (EtG100 206.5mg/L) in urine, 4.3mg/L in blood and 2.1mg/L in vitreous humor. EtS was found in the following mean concentrations: 54.6mg/L in urine (EtS100 123.1mg/L), 1.8mg/L in blood and 0.9mg/L in vitreous humor. Ethanol was detected in more vitreous humor samples (mean concentration 2.0g/kg) than in blood and urine (mean concentration 1.6g/kg and 2.1g/kg respectively). There was no correlation between the ethanol and the marker concentrations and no statistical conclusions could be drawn between the markers and matrices. PMID:21367549

  8. Combined use of fatty acid ethyl esters and ethyl glucuronide in hair for diagnosis of alcohol abuse: interpretation and advantages.

    PubMed

    Pragst, F; Rothe, M; Moench, B; Hastedt, M; Herre, S; Simmert, D

    2010-03-20

    In this study the combined use of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for diagnoses of chronically excessive alcohol abuse is investigated at 174 hair samples from driving ability examination, workplace testing and child custody cases for family courts and evaluated with respect to the basics of interpretation. Using the cut-off values of 0.50 ng/mg for FAEE and 25 pg/mg for EtG, both markers were in agreement in 75% of the cases with 103 negative and 28 positive results and there were 30 cases with FAEE positive and EtG negative and 13 cases with FAEE negative and EtG positive. As the theoretical basis of interpretation, the pharmacokinetics of FAEE and EtG is reviewed for all steps between drinking of ethanol to incorporation in hair with particular attention to relationships between alcohol dose and concentrations in hair. It is shown that the concentrations of both markers are essentially determined by the area under the ethanol concentration in blood vs. time curve AUC(EtOH), despite large inter-individual variations. It is demonstrated by calculation of AUC(EtOH) on monthly basis for moderate, risky and heavy drinking that AUC(EtOH) increases very strongly in the range between 60 and 120 g ethanol per day. This specific feature which is caused by the zero-order elimination of ethanol is a favorable prerequisite for a high discrimination power of the hair testing for alcohol abuse. From the consideration of the different profiles of FAEE and EtG along the hair and in agreement with the literature survey, a standardized hair segment 0-3 cm is proposed with cut-off values of 0.5 ng/mg for FAEE and 30 pg/mg for EtG. This improves also the agreement between FAEE and EtG results in the cases of the present study. A scheme for combined interpretation of FAEE and EtG is proposed which uses the levels of abstinence and the double of the cut-off values as criteria in addition to the cut-off's. Considering the large variations in the relationship

  9. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

    NASA Astrophysics Data System (ADS)

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-07-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions.

  10. Selective Radical-Radical Cross-Couplings: Design of a Formal β-Mannich Reaction.

    PubMed

    Jeffrey, Jenna L; Petronijević, Filip R; MacMillan, David W C

    2015-07-01

    A direct β-coupling of cyclic ketones with imines has been accomplished via the synergistic combination of photoredox catalysis and organocatalysis. Transient β-enaminyl radicals derived from ketones via enamine and oxidative photoredox catalysis readily combine with persistent α-amino radicals in a highly selective hetero radical-radical coupling. This novel pathway to γ-aminoketones is predicated upon the use of DABCO as both a base and an electron transfer agent. This protocol also formally allows for the direct synthesis of β-Mannich products via a chemoselective three-component coupling of aryl aldehydes, amines, and ketones. PMID:26075347

  11. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies.

    PubMed

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-01-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions. PMID:27405843

  12. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

    PubMed Central

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-01-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions. PMID:27405843

  13. Preparation of a bifunctional pyrazosulfuron-ethyl imprinted polymer with hydrophilic external layers by reversible addition-fragmentation chain transfer polymerization and its application in the sulfonylurea residue analysis.

    PubMed

    Yang, Meixian; Zhang, Yingying; Lin, Shen; Yang, Xinlin; Fan, Zhijin; Yang, Lixia; Dong, Xiangchao

    2013-09-30

    A new bifunctional pyrazosulfuron-ethyl imprinted polymer was synthesized by the combination of molecular imprinting technology and living radical polymerization. In the synthesis, the pyrazosulfuron-ethyl imprinted polymer was obtained by the reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization followed by grafting poly(glyceryl monomethacrylate) (pGMMA) by the post-RAFT polymerization. In this research, we used polyethylene glycol (PEG) as the polymeric porogen in order to increase the porosity of the material which is a new porogen application in the precipitation polymerization. The imprinted polymer has selectivity for the template and ability of humic acids exclusion which has shown the merits of molecularly imprinted polymers and restricted access materials. An online solid-phase extraction/HPLC method for the analysis of three sulfonylurea residues in soil samples has been developed and validated. The recovery of 81-99% in the spiked levels of 40-200 μg kg(-1) was obtained and the limit of detection (LOD) and limit of quantification (LOQ) were less than 4.8 and 15.9 μg kg(-1) respectively. The results demonstrated that this bifunctional material can be used for the efficient pyrazosulfuron-ethyl extraction in the sulfonylurea residue analysis from environmental samples. PMID:23953454

  14. Ethanolysis of rapeseed oil - distribution of ethyl esters, glycerides and glycerol between ester and glycerol phases.

    PubMed

    Cernoch, Michal; Hájek, Martin; Skopal, Frantisek

    2010-04-01

    The distribution of ethyl esters, triglycerides, diglycerides, monoglycerides, and glycerol between the ester and glycerol phase was investigated after the ethanolysis of rapeseed oil at various reaction conditions. The determination of these substances in the ester and glycerol phases was carried out by the GC method. The amount of ethyl esters in the glycerol phase was unexpectedly high and therefore the possibility of the reduction of this amount was investigated. The distribution coefficients and the weight distributions of each investigated substance were calculated and compared mutually. The distribution coefficients between the ester and glycerol phase increase in this sequence: glycerol, monoglycerides, diglycerides, ethyl esters, and triglycerides. Soaps and monoglycerides in the reaction mixture cause a worse separation of ethyl esters from the reaction mixture. The existence of a non-separable reaction mixture was observed also, and its composition was determined. PMID:20005094

  15. PERSISTENCE OF METHYL AND ETHYL PARATHION FOLLOWING SPILLAGE ON CONCRETE SURFACES

    EPA Science Inventory

    Tests were carried out to determine the potential hazard of spillage of the pesticides, methyl parathion and ethyl parathion, on concrete surfaces. Results indicated that although a toxic hazard exists, especially for potential contamination of foodstuff, when liquid concentrates...

  16. Rapeseed ethyl ester as bio-lube in 2-cycle engine

    SciTech Connect

    1996-12-31

    The performance of four blends of gasoline with rapeseed ethyl ester (REE) and three commercial 2-cycle oils has been evaluated in engine tests by the University of Idaho. Details and results of the tests are given in the article.

  17. EXTRACTION OF TETRAVALENT PLUTONIUM VALUES WITH METHYL ETHYL KETONE, METHYL ISOBUTYL KETONE ACETOPHENONE OR MENTHONE

    DOEpatents

    Seaborg, G.T.

    1961-08-01

    A process is described for extracting tetravalent plutonium from an aqueous acid solution with methyl ethyl ketone, methyl isobutyl ketone, or acetophenone and with the extraction of either tetravalent or hexavalent plutonium into menthone. (AEC)

  18. Improving lipids with prescription icosapent ethyl after previous use of fish oil dietary supplements.

    PubMed

    Reddy, Kota J; Chowdhury, Sumita

    2016-05-01

    Managing dyslipidemia can be challenging in patients with statin intolerance. We describe the lipid effects of icosapent ethyl 4 g/day (high-purity prescription omega-3 eicosapentaenoic acid) in two coronary artery disease patients with statin intolerance who were self-treating with fish oil dietary supplements. After initiating icosapent ethyl, improvements were noted in the first and second patients, respectively, in total cholesterol (-12%; -21%), LDL cholesterol (-3%; -24%), triglycerides (-34%; -16%), non-HDL cholesterol (-12%; -22%), the omega-3 index (+42%; +8%) and eicosapentaenoic acid levels (+275%; +138%). Icosapent ethyl was well tolerated with no adverse events reported. These cases demonstrated favorable lipid effects with prescription icosapent ethyl treatment that may help optimize the care of high-risk coronary artery disease patients with statin intolerance. PMID:27070379

  19. Calculational and Experimental Investigations of the Pressure Effects on Radical - Radical Cross Combinations Reactions: C2H5 + C2H3

    NASA Technical Reports Server (NTRS)

    Fahr, Askar; Halpern, Joshua B.; Tardy, Dwight C.

    2007-01-01

    Pressure-dependent product yields have been experimentally determined for the cross-radical reaction C2H5 + C2H3. These results have been extended by calculations. It is shown that the chemically activated combination adduct, 1-C4H8*, is either stabilized by bimolecular collisions or subject to a variety of unimolecular reactions including cyclizations and decompositions. Therefore the "apparent" combination/disproportionation ratio exhibits a complex pressure dependence. The experimental studies were performed at 298 K and at selected pressures between about 4 Torr (0.5 kPa) and 760 Torr (101 kPa). Ethyl and vinyl radicals were simultaneously produced by 193 nm excimer laser photolysis of C2H5COC2H3 or photolysis of C2H3Br and C2H5COC2H5. Gas chromatograph/mass spectrometry/flame ionization detection (GC/MS/FID) were used to identify and quantify the final reaction products. The major combination reactions at pressures between 500 (66.5 kPa) and 760 Torr are (1c) C2H5 + C2H3 yields 1-butene, (2c) C2H5 + C2H5 yields n-butane, and (3c) C2H3 + C2H3 yields 1,3-butadiene. The major products of the disproportionation reactions are ethane, ethylene, and acetylene. At moderate and lower pressures, secondary products, including propene, propane, isobutene, 2-butene (cis and trans), 1-pentene, 1,4-pentadiene, and 1,5-hexadiene are also observed. Two isomers of C4H6, cyclobutene and/or 1,2-butadiene, were also among the likely products. The pressure-dependent yield of the cross-combination product, 1-butene, was compared to the yield of n-butane, the combination product of reaction (2c), which was found to be independent of pressure over the range of this study. The [ 1-C4H8]/[C4H10] ratio was reduced from approx.1.2 at 760 Torr (101 kPa) to approx.0.5 at 100 Torr (13.3 kPa) and approx.0.1 at pressures lower than about 5 Torr (approx.0.7 kPa). Electronic structure and RRKM calculations were used to simulate both unimolecular and bimolecular processes. The relative importance

  20. Catalyst-free ethyl biodiesel production from rice bran under subcritical condition

    NASA Astrophysics Data System (ADS)

    Zullaikah, Siti; Afifudin, Riza; Amalia, Rizky

    2015-12-01

    In-situ ethyl biodiesel production from rice bran under subcritical water and ethanol with no catalyst was employed. This process is environmentally friendly and is very flexible in term of feedstock utilization since it can handle relatively high moisture and free fatty acids (FFAs) contents. In addition, the alcohol, i.e. bioethanol, is a non-toxic, biodegradable, and green raw material when produced from non-edible biomass residues, leading to a 100% renewable biodiesel. The fatty acid ethyl esters (FAEEs, ethyl biodiesel) are better than fatty acid methyl esters (FAMEs, methyl biodiesel) in terms of fuel properties, including cetane number, oxidation stability and cold flow properties. The influences of the operating variables such as reaction time (1 - 10 h), ethanol concentration (12.5 - 87.5%), and pressurizing gas (N2 and CO2) on the ethyl biodiesel yield and purity have been investigated systematically while the temperature and pressure were kept constant at 200 °C and 40 bar. The optimum results were obtained at 5 h reaction time and 75% ethanol concentration using CO2 as compressing gas. Ethyl biodiesel yield and purity of 58.78% and 61.35%, respectively, were obtained using rice bran with initial FFAs content of 37.64%. FFAs level was reduced to 14.22% with crude ethyl biodiesel recovery of 95.98%. Increasing the reaction time up to 10 h only increased the yield and purity by only about 3%. Under N2 atmosphere and at the same operating conditions (5h and 75% ethanol), ethyl biodiesel yield and purity decreased to 54.63% and 58.07%, respectively, while FFAs level was increased to 17.93% and crude ethyl biodiesel recovery decreased to 87.32%.

  1. Identification of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) and 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF) with DNA breaking activity in soy sauce.

    PubMed

    Li, X; Hiramoto, K; Yoshida, M; Kato, T; Kikugawa, K

    1998-04-01

    Components with DNA breaking activity in soy sauce were investigated. It was found that there were water soluble high molecular weight DNA breaking components in soy sauce. Two DNA breaking components in the ethyl acetate extract of soy sauce were identified as fragrant components, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) and 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF), in addition to the previously characterized DNA breaking fragrant component 4-hydroxy-5-methyl-3(2H)-furanone (HMF) (Hiramoto et al., 1996b). Characterization of DNA breaking activity of HEMF was performed, and the mechanisms for the breaking were considered. HEMF cleaved the single strands of supercoiled pBR 322 DNA at pH 7.4 dose dependently and time dependently. DNA breaking was inhibited by superoxide dismutase, catalase, hydroxyl radical scavengers, spin trapping agents and metal chelators, and enhanced by Fe(III) ion. Electron spin resonance-spin trapping technique revealed the generation of hydroxyl radical. Hence, active oxygen species derived from interaction of HEMF with metal ions and oxygen participated in the cleavage. HEMF exhibited mutagenicity to Salmonella typhimurium TA100 without metabolic activation and induced micronucleated mouse peripheral reticulocytes. PMID:9651047

  2. Practicing Radical Pedagogy: Balancing Ideals with Institutional Constraints.

    ERIC Educational Resources Information Center

    Sweet, Stephen

    1998-01-01

    Describes radical pedagogy and observes that an overview of "Teaching Sociology" suggests that few teachers fully practice it. Argues that while professors are free to teach radical theory, radical pedagogy is hindered by institutional constraints. Concludes that radical teachers may benefit from remaining more within the confines imposed by their…

  3. Evaluation of Antioxidant, Free Radical Scavenging, and Antimicrobial Activity of Quercus incana Roxb.

    PubMed Central

    Sarwar, Rizwana; Farooq, Umar; Khan, Ajmal; Naz, Sadia; Khan, Sara; Khan, Afsar; Rauf, Abdur; Bahadar, Haji; Uddin, Reaz

    2015-01-01

    Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content, and antimicrobial activity of Q. incana Roxb. In vitro antioxidant activity of the plant fractions were determined by 1,1-diphenyl-2-picrylhydrazyl and nitric oxide scavenging method. Total phenolic contents were determined by gallic acid equivalent and antimicrobial activities were determined by agar well diffusion method. It was observed that Q. incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Q. incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55) and A. flavus (28 mm ± 0.45). Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21 μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL) was fairly good compared to other fractions. The current study of Q. incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity. PMID:26635607

  4. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum.

    PubMed

    Ahmad, Sohail; AbdEl-Salam, Naser M; Ullah, Riaz

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25-225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines. PMID:27597961

  5. Rate constant calculations of H-atom abstraction reactions from ethers by HȮ2 radicals.

    PubMed

    Mendes, Jorge; Zhou, Chong-Wen; Curran, Henry J

    2014-02-27

    In this work, we detail hydrogen atom abstraction reactions from six ethers by the hydroperoxyl radical, including dimethyl ether, ethyl methyl ether, propyl methyl ether, isopropyl methyl ether, butyl methyl ether, and isobutyl methyl ether, in order to test the effect of the functional group on the rate constant calculations. The Møller-Plesset (MP2) method with the 6-311G(d,p) basis set has been employed in the geometry optimizations and frequency calculations of all of the species involved in the above reaction systems. The connections between each transition state and the corresponding local minima have been determined by intrinsic reaction coordinate calculations. Energies are reported at the CCSD(T)/cc-pVTZ level of theory and include the zero-point energy corrections. As a benchmark in the electronic energy calculations, the CCSD(T)/CBS extrapolation was used for the reactions of dimethyl ether + HȮ2 radicals. A systematic calculation of the high-pressure limit rate constants has been performed using conventional transition-state theory, including asymmetric Eckart tunneling corrections, in the temperature range of 500-2000 K. The one dimensional hindrance potentials obtained at MP2/6-311G(d,p) for the reactants and transition states have been used to describe the low frequency torsional modes. Herein, we report the calculated individual, average, and total rate constants. A branching ratio analysis for every reaction site has also been performed. PMID:24483837

  6. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum

    PubMed Central

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25–225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines. PMID:27597961

  7. Investigation of terpinolene + ozone or terpinolene + nitrate radical reaction products using denuder/filter apparatus

    NASA Astrophysics Data System (ADS)

    Harrison, Joel C.; Wells, J. R.

    2013-12-01

    Terpinolene's (1-methyl-4-(propan-2-ylidene)cyclohexene) reaction with ozone or the nitrate radical was investigated using a denuder/filter apparatus in order to characterize gas-phase and particulate reaction products. Identification of the reaction products (i.e., aldehydes, ketones, dicarbonyls and carboxylic acids) was made using two derivatization methods; O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) to derivatize the carbonyl products or 3-Ethyl-1-[3-(dimethylamino)propyl]carbodiimide hydrochloride (EDC) and 2,2,2-trifluoroethylamine hydrochloride (TFEA) to derivatize the carboxylic acid products. Proposed carbonyl products for ozonolysis of terpinolene are: 4-methylcyclohex-3-en-1-one, 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, 3-oxobutanal, and 6-oxo-3-(propan-2-ylidene)heptanal. Proposed carbonyl products for nitrate radical reaction of terpinolene are: 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, and 4-oxopentanal. No carboxylic acid products were detected with either oxidizing reactant.

  8. Efficient method for screening and identification of radical scavengers in the leaves of Olea europaea L.

    PubMed

    Wang, Xiaofei; Li, Chen; Liu, Yewei; Li, Hongbing; Di, Duolong

    2011-03-01

    In this article, an efficient method was developed to screen, isolate and identify the major radical scavengers in the leaves of Olea europaea L. by DPPH-HPLC-DAD, HSCCC and NMR. The method of DPPH-HPLC-DAD was used to screen the major radical scavengers. It was found that three major constituents (A, B, C) in the extract of the leaves of O. europaea L. possessed potential antioxidant activities. In order to identify the chemical structures of those compounds, the HSCCC method with a two-phase solvent system composed of petroleum ether-ethyl acetate-water at an optimized volume ratio of 6:600:700 (v/v/v) together with column chromatography was developed to isolate and purify the active compounds. Pure compounds A (225 mg), B (10 mg) and C (12 mg) with purities 92.6, 95.1 and 96.4%, respectively, were obtained from the crude sample (500 mg). Their structures were identified as oleuropein (A), luteolin-7-O-glucoside (B) and verbascoside (C) by (1) H-NMR and (13) C-NMR. PMID:21321972

  9. Investigation of terpinolene + ozone or terpinolene + nitrate radical reaction products using denuder/filter apparatus

    PubMed Central

    Harrison, Joel C.; Wells, J.R.

    2015-01-01

    Terpinolene’s (1-methyl-4-(propan-2-ylidene)cyclohexene) reaction with ozone or the nitrate radical was investigated using a denuder/filter apparatus in order to characterize gas-phase and particulate reaction products. Identification of the reaction products (i.e., aldehydes, ketones, dicarbonyls and carboxylic acids) was made using two derivatization methods; O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) to derivatize the carbonyl products or 3-Ethyl-1-[3-(dimethylamino)propyl]carbodiimide hydrochloride (EDC) and 2,2,2-trifluoroethylamine hydrochloride (TFEA) to derivatize the carboxylic acid products. Proposed carbonyl products for ozonolysis of terpinolene are: 4-methylcyclohex-3-en-1-one, 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, 3-oxobutanal, and 6-oxo-3-(propan-2-ylidene)heptanal. Proposed carbonyl products for nitrate radical reaction of terpinolene are: 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, and 4-oxopentanal. No carboxylic acid products were detected with either oxidizing reactant. PMID:26527171

  10. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms

    NASA Astrophysics Data System (ADS)

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-05-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4–12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system.

  11. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms.

    PubMed

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-01-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4-12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system. PMID:27225540

  12. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms

    PubMed Central

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-01-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4–12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system. PMID:27225540

  13. Oxidase-peroxidase enzymes of Datura innoxia. Oxidation of formylphenylacetic acid ethyl ester.

    PubMed Central

    Kalyanaraman, V S; Mahadevan, S; Kumar, S A

    1975-01-01

    An enzyme system from Datura innoxia roots oxidizing formylphenylacetic acid ethyl ester was purified 38-fold by conventional methods such as (NH4)2SO4 fractionation, negative adsorption on alumina Cy gel and chromatography on DEAE-cellulose. The purified enzyme was shown to catalyse the stoicheiometric oxidation of formylphenylacetic acid ethyl ester to benzoylformic acid ethyl ester and formic acid, utilizing molecular O2. Substrate analogues such as phenylacetaldehyde and phenylpyruvate were oxidized at a very low rate, and formylphenylacetonitrile was an inhilating agents, cyanide, thiol compounds and ascorbic acid. This enzyme was identical with an oxidase-peroxidase isoenzyme. Another oxidase-peroxidase isoenzyme which separated on DEAE-chromatography also showed formylphenylacetic acid ethyl ester oxidase activity, albeit to a lesser extent. The properties of the two isoenzymes of the oxidase were compared and shown to differ in their oxidation and peroxidation properties. The oxidation of formylphenylacetic acid ethyl ester was also catalysed by horseradish peroxidase. The Datura isoenzymes exhibited typical haemoprotein spectra. The oxidation of formylphenylacetic acid ethyl ester was different from other peroxidase-catalysed reactions in not being activated by either Mn2+ or monophenols. The oxidation was inhibited by several mono- and poly-phenols and by catalase. A reaction mechanism for the oxidation is proposed. PMID:997

  14. Screening of Methanol Extract and Ethyl Acetate Fraction of Abies webbiana Lindl. for Neuropharmacological Activities

    PubMed Central

    Parkash, O.; Kumar, D.; Kumar, S.

    2015-01-01

    Despite a long traditional of use of Abies webbiana Lindl. (Talispatra; family-Pinaceae) in the treatment of mental disorders, the plant has not been investigated systematically to validate its traditional claims. Thus, the present investigation was undertaken with an objective to investigate neuropharmacological activities of methanol extract of Abies webbiana aerial parts and its ethyl acetate fraction. Properly identified aerial parts were defatted with petroleum ether and then extracted with methanol in a Soxhlet apparatus. Ethyl acetate fraction was prepared by partitioning methanol extract with ethyl acetate using standard procedure. In acute toxicity study, no mortality was observed in animals after oral administration of 2 g/kg dose of methanol extract. The methanol extract (200 or 400 mg/kg, p.o.) and ethyl acetate fraction (25 or 50 mg/kg, p.o.) were evaluated for antianxiety, anticonvulsant, antidepressant, sedative, antistress and analgesic activities using well established models. The methanol extract and ethyl acetate fraction of Abies webbiana aerial parts exhibited significant antianxiety, anticonvulsant, antidepressant, sedative, antistress and analgesic activities with respect to control. Preliminary phytochemical screening showed presence of flavonoids in bioactive ethyl acetate fraction of Abies webbiana aerial parts. It is finally concluded that flavonoids are the bioactive constituents responsible for most of neuropharmacological activities of Abies webbiana. PMID:26798167

  15. Ethyl pyruvate protects against sepsis by regulating energy metabolism

    PubMed Central

    Kang, Hongjun; Mao, Zhi; Zhao, Yan; Yin, Ting; Song, Qing; Pan, Liang; Hu, Xin; Hu, Jie; Zhou, Feihu

    2016-01-01

    Background Ethyl pyruvate (EP) is a derivative of pyruvic acid that has been demonstrated to be a potential scavenger of reactive oxygen species as well as an anti-inflammatory agent. In this study, we investigated the protective effects of EP and its role in regulating the energy metabolism in the livers of cecal-ligation-and-puncture-induced septic mice. Methods The animals were treated intraperitoneally with 0.2 mL of Ringer’s lactate solution or an equivalent volume of Ringer’s lactate solution containing EP immediately after cecal ligation and puncture. Each mouse in the Sham group was only subjected to a laparotomy. At 30-, 60-, 180-, and 360-minute time points, we measured the histopathological alterations of the intestines, and the plasma levels of interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor-α, and the total antioxidative capacity, malondialdehyde content, and lactate and lactate/pyruvate levels in livers. Furthermore, we detected the levels of adenosine triphosphate, total adenylate, and energy charge in the livers. Results Our results demonstrated that the administration of EP significantly improved the survival rate and reduced intestinal histological alterations. EP inhibited the plasma levels of IL-1β, IL-6, and tumor necrosis factor-α and increased the IL-10 level. EP significantly inhibited the elevation of the malondialdehyde, lactate, and lactate/pyruvate levels and enhanced the total antioxidative capacity levels in the liver tissues. The downregulation of the adenosine triphosphate, total adenylate, and energy charge levels in the liver tissues was reversed in the septic mice treated with EP. Conclusion The results suggest that EP administration effectively modulates the energy metabolism, which may be an important component in treatment of sepsis. PMID:26966369

  16. Lignin biodegradation and the production of ethyl alcohol from cellulose

    SciTech Connect

    Rosenberg, S.L.; Wilke, C.R.

    1981-02-01

    During the last few years our group has been engaged in developing a biochemical process for the conversion of lignocellulosic materials to ethyl alcohol. Lignin is a barrier to complete cellulose saccharification in this process, but chemical and physical delignification steps are too expensive to be used at the present time. An enzymatic delignification process might be attractive for several reasons: little energy would be expected to be needed, enzymes could be recovered and reused, and useful chemicals might be produced from dissolved lignin. A number of thermophilic and thermotolerant fungi were examined for the ability to rapidly degrade lignocellulose in order to find an organism whcih produced an active lignin-degrading enzyme system. Chryosporium pruinosum and Sporotrichum pulverulentum were found to be active lignocellulose degraders, and C. pruinosum was chosen for further study. Lignin and carbohydrate were degraded when the substrate remained moistened by, but not submerged in, the liquid medium. Attempts were made to demonstrate a cell-free lignin degrading system by both extraction and pressing of cultures grown on moist lignocellulose. Carbohydrate-degrading activity was found but not lignin-degrading activity. This led us to ask whether diffusible lignin-degrading activity could be demonstrated in this organism. The data indicate that the lignin degradation system, or one or more of its components, produced by this organism is either unstable, non-diffusible, or inactive at small distances (about 1 mm) from growing hyphae. At present, studies are being conducted using diffusion cultures to select mutants of C. pruinosum that do produce a diffusible lignin degradation system. We are also examining a number of mesophilic lignin-degrading molds for this ability.

  17. ETHYL CYANIDE ON TITAN: SPECTROSCOPIC DETECTION AND MAPPING USING ALMA

    SciTech Connect

    Cordiner, M. A.; Palmer, M. Y.; Nixon, C. A.; Charnley, S. B.; Mumma, M. J.; Serigano, J.; Irwin, P. G. J.; Teanby, N. A.; Kisiel, Z.; Wang, K.-S.

    2015-02-10

    We report the first spectroscopic detection of ethyl cyanide (C{sub 2}H{sub 5}CN) in Titan’s atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter Array (ALMA). The presence of C{sub 2}H{sub 5}CN in Titan’s ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C{sub 2}H{sub 5}CNH{sup +}. Here we report the detection of 27 rotational lines from C{sub 2}H{sub 5}CN (in 19 separate emission features detected at >3σ confidence) in the frequency range 222–241 GHz. Simultaneous detections of multiple emission lines from HC{sub 3}N, CH{sub 3}CN, and CH{sub 3}CCH were also obtained. In contrast to HC{sub 3}N, CH{sub 3}CN, and CH{sub 3}CCH, which peak in Titan’s northern (spring) hemisphere, the emission from C{sub 2}H{sub 5}CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C{sub 2}H{sub 5}CN. Radiative transfer models show that C{sub 2}H{sub 5}CN is most concentrated at altitudes ≳200 km, suggesting production predominantly in the stratosphere and above. Vertical column densities are found to be in the range (1–5) × 10{sup 14} cm{sup −2}.

  18. Antioxidant phenolic profile from ethyl acetate fraction of Fructus Ligustri Lucidi with protection against hydrogen peroxide-induced oxidative damage in SH-SY5Y cells.

    PubMed

    Ju, Heng-Yin; Chen, Shiu Ching; Wu, Kuo-Jen; Kuo, Hui-Chun; Hseu, You-Cheng; Ching, Hui; Wu, Chi-Rei

    2012-03-01

    In this study, we demonstrated the antioxidant and protective properties of crude extract and fractions from Fructus Ligustri Lucidi (FLL) against hydrogen peroxide (H2O2)-induced oxidative damage in SH-SY5Y cells. The contents of their phytochemical profiles were determined by spectrophotometric methods and high performance liquid chromatography using a photodiode array detector. FLL crude extract possessed appreciable scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl and H2O2. The ethyl acetate (EtOAc) fraction was the most active fraction in scavenging free radicals and H2O2. Following exposure of cells to H2O2, there was a marked decrease in cell survival and intracellular antioxidant enzymes, and then intracellular oxidative stress, the level of lipid peroxidation, and caspase-3 activity were increased. Simultaneous treatment with the EtOAc fraction blocked these H2O2-induced cellular events. Hydroxytyrosol and salidroside are major components of the EtOAc fraction. These results show that the phenolic-enriched EtOAc fraction of FLL contains tyrosol-related derivatives and exerts the protective effects against H2O2 toxicity via its free radical scavenging activity and ability to elevate the levels of antioxidant enzymes. PMID:22142696

  19. Ionizing radiation induced degradation of poly (2-methoxy-5-(2'-ethyl-hexyloxy) -1,4-phenylene vinylene) in solution

    SciTech Connect

    Bronze-Uhle, E. S.; Batagin-Neto, A.; Lavarda, F. C.; Graeff, C. F. O.

    2011-10-01

    In this paper we investigate the causes of the chromatic alteration observed in chloroform solutions of poly (2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) after gamma ray irradiation. Structural and chemical changes were analyzed by gel permeation chromatography, fourier transform infrared spectroscopy, and proton nuclear magnetic resonance techniques and complemented by electronic structure calculations. The results indicate chlorine incorporation in the polymer structure and main chain scission after irradiation. Based on our findings we propose that the main mechanism for the blue-shifts, observed in the UV-Vis absorption spectra of MEH-PPV after irradiation, is the result of a radical attack on the polymer main chain. Gamma rays generate radicals, Cl and CHCl{sub 2} from chloroform radiolysis that attack preferentially the vinyl double bonds of the polymer backbone, breaking the electronic conjugation and eventually the chain. Our results indicate that oxygen does not play a major role in the effect. Electronic spectra simulations were performed based on these assumptions reproducing the UV-Vis experimental results.

  20. Ionizing radiation induced degradation of poly (2-methoxy-5-(2'-ethyl-hexyloxy) -1,4-phenylene vinylene) in solution

    NASA Astrophysics Data System (ADS)

    Bronze-Uhle, E. S.; Batagin-Neto, A.; Lavarda, F. C.; Graeff, C. F. O.

    2011-10-01

    In this paper we investigate the causes of the chromatic alteration observed in chloroform solutions of poly (2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) after gamma ray irradiation. Structural and chemical changes were analyzed by gel permeation chromatography, fourier transform infrared spectroscopy, and proton nuclear magnetic resonance techniques and complemented by electronic structure calculations. The results indicate chlorine incorporation in the polymer structure and main chain scission after irradiation. Based on our findings we propose that the main mechanism for the blue-shifts, observed in the UV-Vis absorption spectra of MEH-PPV after irradiation, is the result of a radical attack on the polymer main chain. Gamma rays generate radicals, •Cl and •CHCl2 from chloroform radiolysis that attack preferentially the vinyl double bonds of the polymer backbone, breaking the electronic conjugation and eventually the chain. Our results indicate that oxygen does not play a major role in the effect. Electronic spectra simulations were performed based on these assumptions reproducing the UV-Vis experimental results.

  1. In Vivo Antioxidant and Anti-Skin-Aging Activities of Ethyl Acetate Extraction from Idesia polycarpa Defatted Fruit Residue in Aging Mice Induced by D-Galactose

    PubMed Central

    Jia, Ran-ran; Chen, Fang

    2014-01-01

    Two different concentrations of D-galactose (D-gal) induced organism and skin aging in Kunming mice were used to examine comprehensively the antioxidant and antiaging activities of ethyl acetate extraction (EAE) from Idesia polycarpa defatted fruit residue for the first time. The oxygen radical absorbance capacity (ORAC) of EAE was 13.09 ± 0.11 μmol Trolox equivalents (TE)/mg, which showed EAE had great in vitro free radical scavenging and antioxidant activity. Biochemical indexes and morphological analysis of all tested tissues showed that EAE could effectively improve the total antioxidant capacity (T-AOC) of the antioxidant defense system of the aging mice, enhance the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) of tissues and serum, increase glutathione (GSH) content and decrease the malondialdehyde (MDA) content, and maintain the skin collagen, elastin, and moisture content. Meanwhile, EAE could effectively attenuate the morphological damage in brain, liver, kidney, and skin induced by D-gal and its effect was not less than that of the well-known L-ascorbic acid (VC) and α-tocopherol (VE). Overall, EAE is a potent natural antiaging agent with great antioxidant activity, which can be developed as a new medicine and cosmetic for the treatment of age-related conditions. PMID:24971146

  2. Choice of Bond Dissociation Enthalpies on which to Base the Stabilization Energies of Simple Radicals: DH(R-H)is Preferred because DH(R-Me) is Perturbed by Changes in Chain Branching

    SciTech Connect

    Poutsma, Marvin L

    2008-01-01

    The relative stabilization energies of radicals, SE(R ), along the simple series methyl/ethyl/i-propyl/t-butyl are known to vary in spread and even direction dependent on which dissociation enthalpies, DH(R-X), they are based on. Using a highly electronegative X is recognized as unwise, but it is not clear whether a choice of X = Me or X = R might not be preferred over the almost universal use of R = H. The enthalpies of isomerization of C4 radical pairs that vary only in the substitution pattern at the radical center but not in carbon skeleton illustrate that R = H is indeed the better choice. Comparisons in the context of recent predictive models for alkane and radical stability indicate that, while relative DH(R-H) values highlight the desired difference in substitution pattern at the radical center, relative DH(R-Me) values are perturbed by differences in skeletal branching or protobranching which are well-known to affect thermochemistry. As a result, SE(R ) values derived from relative DH(R-Me) values are consistently too small. The same pattern is illustrated for prim, sec, and tert allylic and benzylic radicals (larger SE(R )) and for the parent vinyl, phenyl, and ethynyl radicals (negative SE(R )).

  3. Substrate radical intermediates in soluble methane monooxygenase

    SciTech Connect

    Liu Aimin; Jin Yi; Zhang Jingyan; Brazeau, Brian J.; Lipscomb, John D. . E-mail: lipsc001@umn.edu

    2005-12-09

    EPR spin-trapping experiments were carried out using the three-component soluble methane monooxygenase (MMO). Spin-traps 5,5-dimethyl-1-pyrroline N-oxide (DMPO), {alpha}-4-pyridyl-1-oxide N-tert-butylnitrone (POBN), and nitrosobenzene (NOB) were used to investigate the possible formation of substrate radical intermediates during catalysis. In contrast to a previous report, the NADH-coupled oxidations of various substrates did not produce any trapped radical species when DMPO or POBN was present. However, radicals were detected by these traps when only the MMO reductase component and NADH were present. DMPO and POBN were found to be weak inhibitors of the MMO reaction. In contrast, NOB is a strong inhibitor for the MMO-catalyzed nitrobenzene oxidation reaction. When NOB was used as a spin-trap in the complete MMO system with or without substrate, EPR signals from an NOB radical were detected. We propose that a molecule of NOB acts simultaneously as a substrate and a spin-trap for MMO, yielding the long-lived radical and supporting a stepwise mechanism for MMO.

  4. Electrochemistry and spectroelectrochemistry of nitroxyl free radicals

    SciTech Connect

    Fish, J.R.; Swarts, S.G.; Sevilla, M.D.; Malinski, T.

    1988-06-30

    This work reports electrochemical and spectroelectrochemical studies of the two nitroxyl radicals 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy (3-carbamoyl-PROXYL). Oxidation and reduction reactions have been observed in aqueous media over the pH range 2-12 in the potential range -0.8 to +0.8 V by differential pulse voltammetry, cyclic voltammetry, and thin-layer UV-visible spectroelectrochemistry, and the reaction products have been characterized by IR, NMR, and ESR spectrometry. At pH values less than 10, characteristic electrochemical behavior is observed to be analogous for both radicals, and the products from electron transfer compare quite favorably with those found by pulse radiolysis of aqueous solutions of nitroxyl radicals. At pH 2-9, a stable cation from a reversible oxidation and hydroxylamine following an irreversible reduction, as well as hydroxylated cation at pH higher than 9, are the same as those obtained in pulse radiolysis experiments. Spectroscopic evidence indicates that behavior following reduction at high pH differs for the two radicals. At pH 12, reduced TEMPO may undergo structural changes leading to the formation of a new radical consisting of a seven-membered ring.

  5. Radical-pair based avian magnetoreception

    NASA Astrophysics Data System (ADS)

    Procopio, Maria; Ritz, Thorsten

    2014-03-01

    Behavioural experiments suggest that migratory birds possess a magnetic compass sensor able to detect the direction of the geomagnetic. One hypothesis for the basis of this remarkable sensory ability is that the coherent quantum spin dynamics of photoinduced radical pair reactions transduces directional magnetic information from the geomagnetic field into changes of reaction yields, possibly involving the photoreceptor cryptochrome in the birds retina. The suggested radical-pair based avian magnetoreception has attracted attention in the field of quantum biology as an example of a biological sensor which might exploit quantum coherences for its biological function. Investigations on such a spin-based sensor have focussed on uncovering the design features for the design of a biomimetic magnetic field sensor. We study the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

  6. Modeling Radicalization Phenomena in Heterogeneous Populations.

    PubMed

    Galam, Serge; Javarone, Marco Alberto

    2016-01-01

    The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration. PMID:27166677

  7. Modeling Radicalization Phenomena in Heterogeneous Populations

    PubMed Central

    2016-01-01

    The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration. PMID:27166677

  8. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling

    PubMed Central

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-01-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry. PMID:26525888

  9. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling

    NASA Astrophysics Data System (ADS)

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-11-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry.

  10. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling.

    PubMed

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-01-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry. PMID:26525888

  11. Isolation of Hypervalent Group-16 Radicals and Their Application in Organic-Radical Batteries.

    PubMed

    Imada, Yasuyuki; Nakano, Hideyuki; Furukawa, Ko; Kishi, Ryohei; Nakano, Masayoshi; Maruyama, Hitoshi; Nakamoto, Masaaki; Sekiguchi, Akira; Ogawa, Masahiro; Ohta, Toshiaki; Yamamoto, Yohsuke

    2016-01-20

    Using a newly prepared tridentate ligand, we isolated hypervalent sulfur and selenium radicals for the first time and characterized their structures. X-ray crystallography, electron spin resonance spectroscopy, and density functional theory calculations revealed a three-coordinate hypervalent structure. Utilizing the reversible redox reactions between hypervalent radicals and the corresponding anions bearing Li(+), we developed organic radical batteries with these compounds as cathode-active materials. Furthermore, an all-radical battery, with these compounds as the cathode and a silyl radical as the anode, was developed that exhibited a practical discharge potential of ∼ 1.8 V and stable cycle performance, demonstrating the potential of these materials for use in metal-free batteries that can replace conventional Li-ion batteries where Li is used in the metal form. PMID:26721786

  12. Hydroxyl Radical Generation from Environmentally Persistent Free Radicals (EPFRs) in PM2.5

    PubMed Central

    Gehling, William; Khachatryan, Lavrent; Dellinger, Barry

    2015-01-01

    Hydroxyl radicals were generated from an aqueous suspension of ambient PM2.5 and detected utilizing 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap coupled with electron paramagnetic resonance (EPR) spectroscopy. Results from this study suggested the importance of environmentally persistent free radicals (EPFRs) in PM2.5 to generate significant levels of ·OH without the addition of H2O2. Particles for which the EPFRs were allowed to decay over time induced less hydroxyl radical. Additionally, higher particle concentrations produced more hydroxyl radical. Some samples did not alter hydroxyl radical generation when the solution was purged by air. This is ascribed to internal, rather than external surface associated EPFRs. PMID:24004313

  13. Facile synthesis of brush poly(phosphoamidate)s via one-pot tandem ring-opening metathesis polymerization and atom transfer radical polymerization.

    PubMed

    Ding, Liang; Qiu, Jun; Wei, Jun; Zhu, Zhenshu

    2014-09-01

    Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA)-based brush poly(phosphoamidate)s are successfully synthesized by a combination of ring-opening metathesis polymerization (ROMP) and atom transfer radical polymerization (ATRP) following either a commutative two-step procedure or a straightforward one-pot process using Grubbs ruthenium-based catalysts for tandem catalysis. Compared with the traditional polymerization method, combining ROMP and ATRP in a one-pot process allows the preparation of brush copolymers characterized by a relatively moderate molecular weight distribution and quantitative conversion of monomer. Moreover, the surface morphologies and aggregation behaviors of these polymers are studied by AFM and TEM measurements. PMID:24729161

  14. Proposed chemical mechanisms leading to secondary organic aerosol in the reactions of aliphatic amines with hydroxyl and nitrate radicals

    NASA Astrophysics Data System (ADS)

    Price, Derek J.; Clark, Christopher H.; Tang, Xiaochen; Cocker, David R.; Purvis-Roberts, Kathleen L.; Silva, Philip J.

    2014-10-01

    The presence and importance of amines in the atmosphere, including aliphatic amines, continues to gain more attention. The atmospheric reaction mechanisms of these amines with key atmospheric radicals are important to predict both daytime and nighttime atmospheric chemistry. While previous studies have focused on the production of amine salts, this analysis looks at the importance of peroxy radical reactions to the formation of secondary organic aerosol. Atmospheric oxidation mechanisms are presented to explain the observed chemistry. A series of environmental chamber experiments were conducted in which aliphatic tertiary and secondary amines were reacted with either hydroxyl radical (OH) or nitrate radical (NO3). Chemical composition of the aerosol products was obtained with a High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and a Particle Into Liquid Sampler Time of Flight Mass Spectrometer (PILS-ToF-MS), while the chemical composition of the gas-phase products was obtained with a Selected Ion Flow Tube Mass Spectrometer (SIFT-MS). A number of aerosol-phase mass spectra showed highly oxidized fragments at a much higher molecular weight (MW) than the amine precursor. It is proposed that these larger compounds are oligomers formed through peroxy radical reactions with hydrogen rearrangement. Another reaction pathway observed was the formation of amine salts. The relative importance of each pathway to the overall production of aerosol is found to be dependent on the type of amine and oxidant. For example, the oligomers were observed in the tertiary methyl amines, while the formation of amine salts was more prevalent in the secondary and tertiary ethyl amines.

  15. Ethyl acetate-n-butanol gradient solvent system for high-speed countercurrent chromatography to screen bioactive substances in okra.

    PubMed

    Ying, Hao; Jiang, Heyuan; Liu, Huan; Chen, Fangjuan; Du, Qizhen

    2014-09-12

    High-speed countercurrent chromatographic separation (HSCCC) possesses the property of zero-loss of sample, which is very useful for the screening of bioactive components. In the present study, the ethyl acetate-n-butanol gradient HSCCC solvent system composed of n-hexane-ethyl acetate-n-butanol-water was investigated for the screening of bioactive substances. To screen the antiproliferative compounds in okra extract, we used the stationary phase ethyl acetate-n-butanol-water (1:1:10) as the stationary phase, and eluted the antiproliferative components by 6-steps of gradient using mobile phases n-hexane-ethyl acetate (1:2), n-hexane-ethyl acetate (1:4), n-hexane-ethyl acetate (0:4), n-butanol-ethyl acetate (1:4) n-butanol-ethyl acetate (1:2), n-butanol-ethyl acetate (2:2), and n-butanol-ethyl acetate (2:1). The fractions collected from HSCCC separation with the gradient solvent system were assayed for antiproliferative activity against cancer cells. Bioactive components were identified: a major anti-cancer compound, 4'-hydroxy phenethyl trans-ferulate, with middle activity, and a minor anti-cancer compound, carolignan, with strong activity. The result shows that the gradient solvent system is potential for the screening of bioactive compounds from natural products. PMID:25069743

  16. Study of the Reaction Cl + Ethyl Formate at 700-950 Torr and 297 to 435 K: Product Distribution and the Kinetics of the Reaction C2H5OC(═O) → CO2 + C2H5.

    PubMed

    Kaiser, E W

    2016-05-26

    The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis. The initial mixture contained ethyl formate, Cl2, and N2. Cl atoms were generated by UV photolysis of this initial mixture at 360 nm, which dissociates Cl2. The rate constant of reaction 1 was measured at 297 K relative to that of the reaction Cl + C2H5Cl (reaction 2), yielding the rate constant ratio k1/k2 = 1.09 ± 0.05. The final products formed from reaction 1 are ethyl chloroformate, 1-chloroethyl formate, and 2-chloroethyl formate. These products result from the reactions with Cl2 of the three free radicals formed by H atom abstraction from ethylformate in reaction 1. Based on the molar yields of these three chlorinated products, the yields of the three radicals formed from reaction 1 at 297 K are (25 ± 3) mole percent of CH3CH2O(C═O); (67 ± 5) mole percent of CH3CHO(C═O)H; and (8 ± 2) mole percent of CH2CH2O(C═O)H. A second phase of this experiment measured the rate constant of the decarboxylation of the ethoxy carbonyl radical [CH3CH2O(C═O) → CO2 + C2H5, reaction 4] relative to the rate constant of its reaction with Cl2 [CH3CH2O(C═O) + Cl2 → CH3CH2O(C═O)Cl + Cl, reaction 3a]. Over the temperature range 297 to 404 K at 1 atm total pressure, this ratio can be expressed by k4/k3a = 10(23.56±0.22) e(-(12700±375)/RT) molecules cm(-3). Estimating the value of k3a (which has not been measured) based on similar reactions, the expression k4 = 5.8 × 10(12) e(-(12700)/RT) s(-1) is obtained. The estimated error of this rate constant is ± a factor of 2 over the experimental temperature range. This rate expression is compared with recent ab initio calculations of the decarboxylation of the analogous methoxy

  17. Magnetic Bistability in a Discrete Organic Radical.

    PubMed

    Li, Tao; Tan, Gengwen; Shao, Dong; Li, Jing; Zhang, Zaichao; Song, You; Sui, Yunxia; Chen, Sheng; Fang, Yong; Wang, Xinping

    2016-08-17

    Molecular assembly with magnetic bistability has been of considerable interest for application as electronic devices. In contrast to transition-metal complexes, magnetic bistability so far observed in organic radical crystals is mainly caused by intermolecular electron-exchange interaction. We now report that the magnetic bistability in an organic radical can also be caused by intramolecular electron-exchange interaction. The diradical salt of 1,4-di(bisphenylamino)-2,3,5,6,-tetramethylbenzene undergoes a phase transition with a thermal hysteresis loop over the temperature range from 118 to 131 K. The phases above and below the loop correspond to two different singlet states of the diradical dication. The results provide a novel organic radical material as an unprecedented instance of an intramolecular magnetic bistability revalent to the design of functional materials. PMID:27479783

  18. Radical abdominoplasty, including body shaping: representative cases.

    PubMed

    Mühlbauer, W

    1989-01-01

    Even in the age of liposuction there exist certain situations for which abdominoplasty in its radical form is indicated--for example, redundant skin after radical weight loss, the stigmata of postpregnancy syndrome, and localized accumulation of adipose tissue--the lipodystrophies and resistant generalized obesity. Redundant skin after radical weight loss is resected simultaneously around the abdomen, the lumbar regions, the perineum, and the thighs. The typical stigmata of postpregnancy syndrome may be excised through an extended abdominoplasty combined with simultaneous excision and pexy of the inner aspects of the thighs leaving a "bikini" scar behind. A mastopexy may be added. Genetically predisposed localized lipodystrophies in the abdominal lumbar, and upper thigh region may be resected through a circular abdominoplasty with or without simultaneous resection of the perineum and inner thighs. Abdominal aprons often contain umbilical or ventral hernias that may need to be repaired simultaneously. Representative cases are presented and dangers and complications are discussed. PMID:2741749

  19. Resveratrol products resulting by free radical attack

    NASA Astrophysics Data System (ADS)

    Bader, Yvonne; Quint, R. M.; Getoff, Nikola

    2008-06-01

    Trans-resveratrol ( trans-3,4',5-trihydroxystilbene; RES), which is contained in red wine and many plants, is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. Among other duties, RES has been reported to have anti-carcinogenetic activities, which could be attributed to its antioxidant properties. The degradation of RES was studied under various conditions. The products (aldehydes, carboxylic acids, etc.) generated from RES by the attack of free radicals were registered as a function of the radical concentration (absorbed radiation dose). Based on the obtained data it appears that the OH radicals are initiating the rather complicated process, which involves of the numerous consecutive reactions. A possible starting reaction mechanism is presented.

  20. Antioxidant and radical scavenging properties of curcumin.

    PubMed

    Ak, Tuba; Gülçin, Ilhami

    2008-07-10

    Curcumin (diferuoyl methane) is a phenolic compound and a major component of Curcuma longa L. In the present paper, we determined the antioxidant activity of curcumin by employing various in vitro antioxidant assays such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH*) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by the Fe(3+)-Fe(2+) transformation method, superoxide anion radical scavenging by the riboflavin/methionine/illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe(2+)) chelating activities. Curcumin inhibited 97.3% lipid peroxidation of linoleic acid emulsion at 15 microg/mL concentration (20 mM). On the other hand, butylated hydroxyanisole (BHA, 123 mM), butylated hydroxytoluene (BHT, 102 mM), alpha-tocopherol (51 mM) and trolox (90 mM) as standard antioxidants indicated inhibition of 95.4, 99.7, 84.6 and 95.6% on peroxidation of linoleic acid emulsion at 45 microg/mL concentration, respectively. In addition, curcumin had an effective DPPH* scavenging, ABTS*(+) scavenging, DMPD*(+) scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe(3+)) reducing power and ferrous ions (Fe(2+)) chelating activities. Also, BHA, BHT, alpha-tocopherol and trolox, were used as the reference antioxidant and radical scavenger compounds. According to the present study, curcumin can be used in the pharmacological and food industry because of these properties. PMID:18547552

  1. Total radical yields from tropospheric ethene ozonolysis.

    PubMed

    Alam, Mohammed S; Camredon, Marie; Rickard, Andrew R; Carr, Timo; Wyche, Kevin P; Hornsby, Karen E; Monks, Paul S; Bloss, William J

    2011-06-21

    The gas-phase reactions of ozone with alkenes can be significant sources of free radicals (OH, HO(2) and RO(2)) in the Earth's atmosphere. In this study the total radical production and degradation products from ethene ozonolysis have been measured, under conditions relevant to the troposphere, during a series of detailed simulation chamber experiments. Experiments were carried out in the European photoreactor EUPHORE (Valencia, Spain), utilising various instrumentation including a chemical-ionisation-reaction time-of-flight mass-spectrometer (CIR-TOF-MS) measuring volatile organic compounds/oxygenated volatile organic compounds (VOCs/OVOCs), a laser induced fluorescence (LIF) system for measuring HO(2) radical products and a peroxy radical chemical amplification (PERCA) instrument measuring HO(2) + ΣRO(2). The ethene + ozone reaction system was investigated with and without an OH radical scavenger, in order to suppress side reactions. Radical concentrations were measured under dry and humid conditions and interpreted through detailed chemical chamber box modelling, incorporating the Master Chemical Mechanism (MCMv3.1) degradation scheme for ethene, which was updated to include a more explicit representation of the ethene-ozone reaction mechanism.The rate coefficient for the ethene + ozone reaction was measured to be (1.45 ± 0.25) × 10(-18) cm(3) molecules(-1) s(-1) at 298 K, and a stabilised Criegee intermediate yield of 0.54 ± 0.12 was determined from excess CO scavenger experiments. An OH radical yield of 0.17 ± 0.09 was determined using a cyclohexane scavenger approach, by monitoring the formation of the OH-initiated cyclohexane oxidation products and HO(2). The results highlight the importance of knowing the [HO(2)] (particularly under alkene limited conditions and high [O(3)]) and scavenger chemistry when deriving radical yields. An averaged HO(2) yield of 0.27 ± 0.07 was determined by LIF/model fitting. The observed yields are interpreted in terms of

  2. Resonance ionization detection of combustion radicals

    SciTech Connect

    Cool, T.A.

    1993-12-01

    Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated aromatic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and disposal of hazardous chemical wastes. Selective laser ionization techniques are used in this laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames.

  3. Evolution of radical mastectomy for breast cancer

    PubMed Central

    Plesca, M; Bordea, C; El Houcheimi, B; Ichim, E; Blidaru, A

    2016-01-01

    Surgical treatment of breast cancer has been marked by a constant evolution since the Halsted radical mastectomy described in the late 19th century has become the current standard Madden radical mastectomy, a breast surgery that involves the ablation of tissue with the axillary lymphatic preserving both pectoral muscles. The purpose of this paper was to present the stages that have marked the evolution of this intervention and to provide an overview of the way breast cancer has been understood and treated in the last century. PMID:27453752

  4. Cell damage by oxygen free radicals.

    PubMed

    Bellomo, G

    1991-02-01

    The exposure of isolated and cultured cells to oxygen free radicals generated extracellularly or intracellularly during the metabolism of foreing compounds results in the development of damage that eventually lead to cell death. Multiple mechanisms are involved in these cytopathological processes, including direct attack of free radicals to macromolecules essential for cell life, as well as indirect activation of catabolic processes such as proteases, endonucleases and phospholipases. A key role in triggering these indirect events is played by Ca(2+) whose cytosolic concentration during oxidative stress raises well above the physiological limits. PMID:22358959

  5. [Robot-assisted radical prostatectomy: surgical techniques].

    PubMed

    Kojima, Yoshiyuki; Sato, Yuichi; Ogawa, Soichiro; Haga, Nobuhiro; Yanagida, Tomohiko

    2016-01-01

    Robot-assisted radical prostatectomy (RARP) for the patients with localized prostate cancer is increasingly being adopted around the world. The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) provides the advantages of simplification and precision of exposure and suturing because of allowing movements of the robotic arm in real time with increased degree of freedom and magnified 3-dimensional view. Therefore, RARP has been expected to provide superior therapeutic benefit to patients in terms of surgical outcome to open or laparoscopic radical prostatectomy. In this review, we provide our technical aspects and tips and tricks of RARP to improve surgical outcome and postoperative quality of life. PMID:26793888

  6. Radical Behaviorism and Buddhism: Complementarities and Conflicts

    PubMed Central

    Diller, James W; Lattal, Kennon A

    2008-01-01

    Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism. The present review therefore considers heretofore unconsidered points of comparison between Buddhism and radical behaviorism in terms of their respective goals, conceptualization of human beings, and the outcomes of following either philosophy. From these comparisons it is concluded that the commonalities discerned between these two philosophies may enhance both philosophical systems. PMID:22478509

  7. Free-radical kinetics of coal liquefaction

    SciTech Connect

    Wang, M.; Smith, J.M.; McCoy, B.J.

    1994-07-16

    A rate expression with first- and second-order terms in the concentration of extractable compounds in solid coal particles is derived from a fundamental free-radical mechanism. The expression was suggested empirically by prior experiments for coal liquefaction in the presence of a hydrogen-donor solvent. Radical reactions are considered to occur in both coal and in solvent. The long-chain approximation justifies the neglect of initiation, hydrogen abstraction, and termination rates as quantitatively insignificant relative to propagation reaction rates.

  8. Resonant cavity spectroscopy of radical species

    NASA Astrophysics Data System (ADS)

    Ritchie, Grant

    2015-04-01

    Photo-oxidation in the troposphere is highly complex, being initiated by short lived radical species, in the daytime dominated by the hydroxyl radical, OH, with contributions from Cl atoms, and at night by either NO3 radicals or ozone. Chemical oxidation cycles, which couple OH, HO2 and peroxy (RO2) radical species, remove primary emitted trace species which are harmful to humans or to the wider environment. However, many of the secondary products produced by atmospheric photo-oxidation are also directly harmful, for example O3, NO2, acidic and multifunctional species, many of which are of low volatility and are able to partition effectively to the condensed phase, creating secondary organic aerosol (SOA), which contributes a significant fraction of tropospheric aerosol, with associated impacts on climate and human health. The accuracy of atmospheric models to predict these impacts necessarily requires accurate knowledge of the chemical oxidative cycling. Two of the simplest intermediates are the hydroperoxy radical, HO2, and the smallest and dominant organic peroxy radical, CH3O2, formed directly by the reactions of OH with CO/O2 and CH4/O2, respectively, and indirectly following the oxidation of larger VOCs. OH, HO2 and RO2 (collectively known as ROx) are rapidly cycled, being at the centre of tropospheric oxidation, and hence are some of the best targets for models to compare with field data. The reaction of HO2 and RO2 with NO constitutes the only tropospheric in-situ source of O3. Despite their importance, neither HO2 nor CH3O2 is measured directly in the atmosphere. HO2 is only measured indirectly following its conversion to OH and CH3O2 is not measured at all. Typically only the sum of RO2 radicals is measured, making no distinction between different organic peroxy radicals. This contribution will detail recent studies using (i) optical feedback cavity enhanced absorption spectroscopy with both quantum and inter-band cascade lasers in the mid-IR, and (ii

  9. Laboratory Detection of the Trans-Gauche Conformer of Ethyl Formate.

    NASA Astrophysics Data System (ADS)

    Neill, Justin L.; Muckle, Matt T.; Zaleski, Daniel P.; Pate, Brooks H.; Lattanzi, V.; Spezzano, S.; McCarthy, M. C.

    2010-06-01

    Ethyl formate has two coordinates of conformational flexibility, in the ester (O=C-O-C) and ethyl (C-O-C-C) dihedral angles. Two conformers, one with a cis ester and trans ethyl orientation, the other with a cis ester and gauche ethyl orientation, have been previously detected by rotational spectroscopy. In addition, the cis-trans isomer, the lowest-energy conformer, has recently been detected in the SgrB2(N) hot core. The third conformer of ethyl formate, with a trans ester orientation and gauche ethyl orientation, is significantly higher in energy than the cis-trans conformer according to electronic structure calculations (1900 cm-1, or 1330 K), but there is a barrier of 2870 cm-1 (2000 K) for this conformer to relax into the more stable cis ester potential well, and so local thermodynamic equilibrium between these conformers is not expected in the interstellar medium. Similar behavior is found for the trans ester conformer of methyl formate, for which a tentative detection in SgrB2(N) was presented at this meeting last year, with a column density roughly 1% of that of the more stable cis isomer. Here we report the laboratory detection of trans-gauche ethyl formate using Fourier transform microwave spectroscopy; its low population at room temperature equilibrium has been enhanced by the use of a pulsed discharge nozzle. The spectrum is complicated by a low barrier (140 cm-1) to tunneling between equivalent structures. J.M. Riveros and E.B. Wilson, J. Chem. Phys. 46, 4605 (1967). A. Belloche. et al., A&A 499, 215 (2009). M.T. Muckle et al., RH15, 64th International Symposium on Molecular Spectroscopy (2009).

  10. Glutathione--hydroxyl radical interaction: a theoretical study on radical recognition process.

    PubMed

    Fiser, Béla; Jójárt, Balázs; Csizmadia, Imre G; Viskolcz, Béla

    2013-01-01

    Non-reactive, comparative (2 × 1.2 μs) molecular dynamics simulations were carried out to characterize the interactions between glutathione (GSH, host molecule) and hydroxyl radical (OH(•), guest molecule). From this analysis, two distinct steps were identified in the recognition process of hydroxyl radical by glutathione: catching and steering, based on the interactions between the host-guest molecules. Over 78% of all interactions are related to the catching mechanism via complex formation between anionic carboxyl groups and the OH radical, hence both terminal residues of GSH serve as recognition sites. The glycine residue has an additional role in the recognition of OH radical, namely the steering. The flexibility of the Gly residue enables the formation of further interactions of other parts of glutathione (e.g. thiol, α- and β-carbons) with the lone electron pair of the hydroxyl radical. Moreover, quantum chemical calculations were carried out on selected GSH/OH(•) complexes and on appropriate GSH conformers to describe the energy profile of the recognition process. The relative enthalpy and the free energy changes of the radical recognition of the strongest complexes varied from -42.4 to -27.8 kJ/mol and from -21.3 to 9.8 kJ/mol, respectively. These complexes, containing two or more intermolecular interactions, would be the starting configurations for the hydrogen atom migration to quench the hydroxyl radical via different reaction channels. PMID:24040010

  11. Radical scavenging ability of some compounds isolated from Piper cubeba towards free radicals.

    PubMed

    Aboul-Enein, Hassan Y; Kładna, Aleksandra; Kruk, Irena

    2011-01-01

    The purpose of this study was to identify the antioxidant activity of 16 compounds isolated from Piper cubeba (CNCs) through the extent of their capacities to scavenge free radicals, hydroxyl radical (HO(•)), superoxide anion radical O•(2)(-) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•)), in different systems. Electron paramagnetic resonance (EPR) and 5,5-dimethyl-1-pyrroline-N-oxide, DMPO, as the spin trap, and chemiluminescence techniques were applied. Using the Fenton-like reaction [Fe(II) + H(2)O(2)], CNCs were found to inhibit DMPO-OH radical formation ranging from 5 to 57% at 1.25 mmol L(-1) concentration. The examined CNCs also showed a high DPPH antiradical activity (ranging from 15 to 99% at 5 mmol L(-1) concentration). Furthermore, the results indicated that seven of the 16 tested compounds may catalyse the conversion of superoxide radicals generated in the potassium superoxide/18-crown-6 ether system, thus showing superoxide dismutase-like activity. The data obtained suggest that radical scavenging properties of CNCs might have potential application in many plant medicines. PMID:21681910

  12. Photooxidation of methyl sulfide, ethyl sulfide, and methanethiol

    SciTech Connect

    Grosjean, D.

    1984-06-01

    Products of sunlight-irradiated mixtures of oxides of nitrogen and alkyl sulfides (RSR, R = CH/sub 3/, C/sub 2/H/sub 5/) and methanethiol (CH/sub 3/SH) in air include formaldehyde (R = CH/sub 3/), acetaldehyde and PAN (R = C/sub 2/H/sub 5/), sulfur dioxide, and alkyl nitrates (RONO/sub 2/) as well as particulate alkanesulfonic acids (RSO/sub 2/OH) and inorganic sulfate. The nature and yields of gaseous and particulate products are discussed in terms of OH-initiated reaction pathways, including C-S bond scission, and subsequent reactions of alkythiyl radicals (RS), including those leading to photolabile RSNO and stable RSNO/sub 2/ products for which indirect evidence is presented. SO/sub 2/ yields are found to vary according to the relative importance of the competing pathways RS + O/sub 2/ (a) and RS + NO/sub 2/ (b), for which a ratio k/sub b/ / k/sub a/ approx. 2 x 10/sup 6/ is derived from data for irradiated RSR-NO/sub x/, RSH-Cl/sub 2/, and RSH-Cl/sub 2/-NO/sub 2/ mixtures.

  13. Validation of a novel method to identify in utero ethanol exposure: simultaneous meconium extraction of fatty acid ethyl esters, ethyl glucuronide, and ethyl sulfate followed by LC-MS/MS quantification

    PubMed Central

    Himes, Sarah K.; Concheiro, Marta; Scheidweiler, Karl B.

    2015-01-01

    Presence of fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) in meconium, the first neonatal feces, identifies maternal alcohol consumption during pregnancy. Current meconium alcohol marker assays require separate analyses for FAEE and EtG/EtS. We describe development and validation of the first quantitative liquid chromatography tandem mass spectrometry assay for 9 FAEEs, EtG, and EtS in 100 mg meconium. For the first time, these alcohol markers are analyzed in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. 100 mg meconium was homogenized in methanol and centrifuged. The supernatant was divided, and applied to two different solid phase extraction columns for optimized analyte recovery. Limits of quantification for ethyl laurate, myristate, linolenate, palmitoleate, arachidonate, linoleate, palmitate, oleate, and stearate ranged from 25–50 ng/g, with calibration curves to 2,500–5,000 ng/g. EtG and EtS linear dynamic ranges were 5–1,000 and 2.5–500 ng/g, respectively. Mean bias and between-day imprecision were <15 %. Extraction efficiencies were 51.2–96.5 %. Matrix effects ranged from −84.7 to 16.0 %, but were compensated for by matched deuterated internal standards when available. All analytes were stable (within ±20 % change from baseline) in 3 authentic positive specimens, analyzed in triplicate, after 3 freeze/thaw cycles (−20 °C). Authentic EtG and EtS also were stable after 12 h at room temperature and 72 h at 4 °C; some FAEE showed instability under these conditions, although there was large inter-subject variability. This novel method accurately detects multiple alcohol meconium markers and enables comparison of markers for maternal alcohol consumption. PMID:24408304

  14. RadicalLocator: A software tool for identifying the radicals in Chinese characters.

    PubMed

    Yu, Lili; Reichle, Erik D; Jones, Mathew; Liversedge, Simon P

    2015-09-01

    This article describes a new software tool called RadicalLocator that can be used to automatically identify (e.g., for visual inspection) individual target radicals (i.e., groups of strokes) in written Chinese characters. We first briefly clarify why this software is useful for research purposes and discuss the factors that make this pattern recognition task so difficult. We then describe how the software can be downloaded and installed, and used to identify the radicals in characters for the purposes of, for example, selecting materials for psycholinguistic experiments. Finally, we discuss several known limitations of the software and heuristics for addressing them. PMID:25169830

  15. Fumigation of wheat using liquid ethyl formate plus methyl isothiocyanate in 50-tonne farm bins.

    PubMed

    Ren, Yonglin; Lee, Byungho; Mahon, Daphne; Xin, Ni; Head, Matthew; Reid, Robin

    2008-04-01

    Australian Standard White wheat, Triticum aestivum L. (a marketing grade with mixed grain hardness),with a moisture content of 12.5% was fumigated with a new ethyl formate formulation (95% ethyl formate plus 5% methyl isothiocyanate) identified and developed by Commonwealth Scientific and Industrial Research Organization Entomology, Canberra, Australia. Wheat was fumigated with the formulation at a calculated application rate of 80 g/m3 in two 50-tonne sealed metal vertical silos located at Fisherman Islands, Queensland, Australia. Access was gained through the top of the silo where the application of the formulation was completed within a few minutes by pouring it onto the top of the wheat. After 2 h of recirculation, using a 0.5-kW fan, the in-bin concentrations of ethyl formate achieved equilibrium with a concentration variation < 7%. The ethyl formate concentration, in both silos 1 and 2, during the first day's exposure period remained above 10 g/m3. The concentration of ethyl formate by time product achieved was 790 and 650 g h/m3 in silos 1 and 2, respectively. In silo 1, the formulation was sufficient to kill all life stages of mixed age cultures of Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Tribolium castaneum (Herbst). In silo 2, control was 100% for R. dominica and T. castaneum and 99.4% for S. oryzae. After 5 d fumigation, the silo top-hatch was opened but no forced aeration was initiated. The in-bin concentration of ethyl formate was lower than the Australian experimental threshold limit value of 100 ppm. The ethyl formate and methyl isothiocyanate residues in the grain had declined to below the Australian experimental maximum residue limit of 0.2 and 0.1 mg/kg, respectively. The workspace and environmental levels of ethyl formate and methyl isothiocyanate were less than the detection limit of 0.1 ppm. The treatment with ethyl formate formulation had no affect on the wheat germination and seed color compared with untreated controls. PMID

  16. Brewing industry potential for the immediate and near-term production of fuel-grade ethyl alcohol. Final report

    SciTech Connect

    Mulloney, J.A. Jr.

    1980-04-15

    The brewing industry is described as it relates to productive facilities and potential for fuel grade ethyl alcohol production. The brewing process is compared to the fuel grade ethyl alcohol process in a brewery. A description is given for retrofitting a brewery as a distilled spirits plant. The following are included: estimated capital requirements and alcohol costs, targets of opportunity, barriers and actions affecting brewery production of ethyl alcohol, suggested action programs, and recommended program activities. (MHR)

  17. Designed metalloprotein stabilizes a semiquinone radical

    NASA Astrophysics Data System (ADS)

    Ulas, Gözde; Lemmin, Thomas; Wu, Yibing; Gassner, George T.; Degrado, William F.

    2016-04-01

    Enzymes use binding energy to stabilize their substrates in high-energy states that are otherwise inaccessible at ambient temperature. Here we show that a de novo designed Zn(II) metalloprotein stabilizes a chemically reactive organic radical that is otherwise unstable in aqueous media. The protein binds tightly to and stabilizes the radical semiquinone form of 3,5-di-tert-butylcatechol. Solution NMR spectroscopy in conjunction with molecular dynamics simulations show that the substrate binds in the active site pocket where it is stabilized by metal-ligand interactions as well as by burial of its hydrophobic groups. Spectrochemical redox titrations show that the protein stabilized the semiquinone by reducing the electrochemical midpoint potential for its formation via the one-electron oxidation of the catechol by approximately 400 mV (9 kcal mol-1). Therefore, the inherent chemical properties of the radical were changed drastically by harnessing its binding energy to the metalloprotein. This model sets the basis for designed enzymes with radical cofactors to tackle challenging chemistry.

  18. Radical Negativity: Music Education for Social Justice

    ERIC Educational Resources Information Center

    McLaren, Peter

    2011-01-01

    According to Hedges (2010), the real enemies of the liberal class are radical thinkers such as Noam Chomsky and Ralph Nader, iconoclastic intellectuals who possess the moral autonomy to defy the power elite. While this author agrees with Hedges, he would take this argument even further. In this article, the author argues that the real enemy of…

  19. Designed metalloprotein stabilizes a semiquinone radical

    PubMed Central

    Ulas, Gözde; Lemmin, Thomas; Wu, Yibing; Gassner, George T.; DeGrado, William F.

    2016-01-01

    Enzymes use binding energy to stabilize their substrates in high-energy states that are otherwise inaccessible at ambient temperature. Here we show that a de novo designed Zn(ii) metalloprotein stabilizes a chemically reactive organic radical that is otherwise unstable in aqueous media. The protein binds tightly to and stabilizes the radical semiquinone form of 3,5-di-tert-butylcatechol. Solution NMR spectroscopy in conjunction with molecular dynamics simulations show that the substrate binds in the active site pocket where it is stabilized by metal–ligand interactions as well as by burial of its hydrophobic groups. Spectrochemical redox titrations show that the protein stabilized the semiquinone by reducing the electrochemical midpoint potential for its formation via the one-electron oxidation of the catechol by approximately 400 mV (9 kcal mol−1). Therefore, the inherent chemical properties of the radical were changed drastically by harnessing its binding energy to the metalloprotein. This model sets the basis for designed enzymes with radical cofactors to tackle challenging chemistry. PMID:27001731

  20. Radical Agendas? The Politics of Adult Education.

    ERIC Educational Resources Information Center

    Westwood, Sallie, Ed.; Thomas, J. E., Ed.

    This book brings together eight of the most significant papers published in the journal "Studies in the Education of Adults" from the 1970s and 1980s, together with three new essays that place the earlier material in context. It examines the changes in British adult education between 1970 and 1990 and is concerned with the place of radicalism in…

  1. Serendipitous findings while researching oxygen free radicals.

    PubMed

    Floyd, Robert A

    2009-04-15

    This review is based on the honor of receiving the Discovery Award from the Society of Free Radical Biology and Medicine. The review is reflective and presents our thinking that led to experiments that yielded novel observations. Critical questioning of our understanding of oxygen free radicals in biomedical problems led us to use and develop more direct and extremely sensitive methods. This included nitrone free radical spin trapping and HPLC-electrochemical detection. This technology led to the pioneering use of salicylate to trap hydroxyl free radicals and show increased flux in ischemia/reperfused brain regions and also to first sensitively detect 8-hydroxyl-2-deoxyguanosine in oxidatively damaged DNA and help assess its role in cancer development. We demonstrated that methylene blue (MB) photoinduces formation of 8-hydroxyguanine in DNA and RNA and discovered that MB sensitively photoinactivates RNA viruses, including HIV and the West Nile virus. Studies in experimental stroke led us serendipitously to discover that alpha-phenyl-tert-butylnitrone (PBN) was neuroprotective if given after the stroke. This led to extensive commercial development of NXY-059, a PBN derivative, for the treatment of stroke. More recently we discovered that PBN nitrones have potent anti-cancer activity and are active in preventing hearing loss caused by acute acoustical trauma. PMID:19439210

  2. DNP with Trityl Radicals in Deuterated Polyethylene

    NASA Astrophysics Data System (ADS)

    Wang, Li; Meyer, W.; Berlin, A.; Herick, J.; Hess, C.; Reicherz, G.

    2016-02-01

    Chemically doping with trityl radicals was performed in fully deuterated polyethylene. The behavior of paramagnetic centers has been investigated by ESR X-band spectrometer. The highest deuteron polarization was 8% at 2.5 T and 1 K with a spin concentration of 3 × 1019 spins/g.

  3. Unimolecular reaction dynamics of free radicals

    SciTech Connect

    Terry A. Miller

    2006-09-01

    Free radical reactions are of crucial importance in combustion and in atmospheric chemistry. Reliable theoretical models for predicting the rates and products of these reactions are required for modeling combustion and atmospheric chemistry systems. Unimolecular reactions frequently play a crucial role in determining final products. The dissociations of vinyl, CH2= CH, and methoxy, CH3O, have low barriers, about 13,000 cm-1 and 8,000 cm-1, respectively. Since barriers of this magnitude are typical of free radicals these molecules should serve as benchmarks for this important class of reactions. To achieve this goal, a detailed understanding of the vinyl and methoxy radicals is required. Results for dissociation dynamics of vinyl and selectively deuterated vinyl radical are reported. Significantly, H-atom scrambling is shown not to occur in this reaction. A large number of spectroscopic experiments for CH3O and CHD2O have been performed. Spectra recorded include laser induced fluorescence (LIF), laser excited dispersed fluorescence (LEDF), fluorescence dip infrared (FDIR) and stimulated emission pumping (SEP). Such results are critical for implementing dynamics experiments involving the dissociation of methoxy.

  4. Radical Constructivism, and the Sin of Relativism

    ERIC Educational Resources Information Center

    Quale, Andreas

    2007-01-01

    The epistemology of "relativism" that is featured by the theory of radical constructivism is addressed. In particular, I examine several objections, all based on this epistemic position of relativism, that are often raised by critics of the theory: the charge of "reality denial" (which, it is often claimed, must lead ultimately to the…

  5. Radical Feminism and the Subject of Writing.

    ERIC Educational Resources Information Center

    Rhodes, Jacqueline

    The radical feminists of the late 1960s and early 1970s, as well as their online counterparts today, offer provocative examples of networked textuality, a discourse dependent on the constant and visible contextualization of self and writing within the discourses of hegemony. Given its potential use for liberatory writing pedagogies, it seems…

  6. Density functional calculations on model tyrosyl radicals.

    PubMed Central

    Himo, F; Gräslund, A; Eriksson, L A

    1997-01-01

    A gradient-corrected density functional theory approach (PWP86) has been applied, together with large basis sets (IGLO-III), to investigate the structure and hyperfine properties of model tyrosyl free radicals. In nature, these radicals are observed in, e.g., the charge transfer pathways in photosystem II (PSII) and in ribonucleotide reductases (RNRs). By comparing spin density distributions and proton hyperfine couplings with experimental data, it is confirmed that the tyrosyl radicals present in the proteins are neutral. It is shown that hydrogen bonding to the phenoxyl oxygen atom, when present, causes a reduction in spin density on O and a corresponding increase on C4. Calculated proton hyperfine coupling constants for the beta-protons show that the alpha-carbon is rotated 75-80 degrees out of the plane of the ring in PSII and Salmonella typhimurium RNR, but only 20-30 degrees in, e.g., Escherichia coli, mouse, herpes simplex, and bacteriophage T4-induced RNRs. Furthermore, based on the present calculations, we have revised the empirical parameters used in the experimental determination of the oxygen spin density in the tyrosyl radical in E. coli RNR and of the ring carbon spin densities, from measured hyperfine coupling constants. Images FIGURE 1 FIGURE 5 PMID:9083661

  7. Dynamics of poly(4-hydroxystyrene) radical cation

    NASA Astrophysics Data System (ADS)

    Okamoto, Kazumasa; Kozawa, Takahiro; Tagawa, Seiichi

    2008-03-01

    Poly(4-hydroxystyrene) (PHS) has been used in KrF excimer laser (248 nm) lithography as a backbone polymer, and is also a promising material for EUV or electron beam lithography. Analysis of the intermediate species is important for the control of reactions in resist materials. Since the size of integrated circuits fabricated for mass production will decrease below 30 nm and the size error must also be decreased to the molecular level, the elucidation of proton dynamics at the molecular level is also important for reducing the deviation of the resist pattern size. In this study, the dynamics of PHS radical cations were studied, because PHS radical cation is main source of proton. The transient absorption of PHS was observed in the near-infrared region (NIR) in p-dioxane solutions by pulse radiolysis. The intramolecular PHS dimer radical cation (M2 +.) were observed, whereas p-cresol shows no distinct CR band. Although the radical cations of phenol derivatives are known to be easily deprotonated, it was found that M2 +. formation prevents deprotonation by its charge resonance stabilization.

  8. The Radical Faculty -- What Are Its Goals?

    ERIC Educational Resources Information Center

    Kampf, Louis

    According to radical faculty members and students, universities have been contradicting their humanistic educational ideals by concentrating on competitive professionalism and non-academic research in a struggle for institutional power in a preponderantly capitalistic society. It is their belief that meaningful education provides intellectual…

  9. Designed metalloprotein stabilizes a semiquinone radical.

    PubMed

    Ulas, Gözde; Lemmin, Thomas; Wu, Yibing; Gassner, George T; DeGrado, William F

    2016-04-01

    Enzymes use binding energy to stabilize their substrates in high-energy states that are otherwise inaccessible at ambient temperature. Here we show that a de novo designed Zn(II) metalloprotein stabilizes a chemically reactive organic radical that is otherwise unstable in aqueous media. The protein binds tightly to and stabilizes the radical semiquinone form of 3,5-di-tert-butylcatechol. Solution NMR spectroscopy in conjunction with molecular dynamics simulations show that the substrate binds in the active site pocket where it is stabilized by metal-ligand interactions as well as by burial of its hydrophobic groups. Spectrochemical redox titrations show that the protein stabilized the semiquinone by reducing the electrochemical midpoint potential for its formation via the one-electron oxidation of the catechol by approximately 400 mV (9 kcal mol(-1)). Therefore, the inherent chemical properties of the radical were changed drastically by harnessing its binding energy to the metalloprotein. This model sets the basis for designed enzymes with radical cofactors to tackle challenging chemistry. PMID:27001731

  10. Emerging themes in radical SAM chemistry

    PubMed Central

    Shisler, Krista A; Broderick, Joan B

    2014-01-01

    Enzymes in the radical SAM (RS) superfamily catalyze a wide variety of reactions through unique radical chemistry. The characteristic markers of the superfamily include a [4Fe–4S] cluster coordinated to the protein via a cysteine triad motif, typically CX3CX2C, with the fourth iron coordinated by S-adenosylmethionine (SAM). The SAM serves as a precursor for a 5′-deoxyadenosyl radical, the central intermediate in nearly all RS enzymes studied to date. The SAM-bound [4Fe–4S] cluster is located within a partial or full triosephosphate isomerase (TIM) barrel where the radical chemistry occurs protected from the surroundings. In addition to the TIM barrel and a RS [4Fe–4S] cluster, many members of the superfamily contain additional domains and/or additional Fe–S clusters. Recently characterized superfamily members are providing new examples of the remarkable range of reactions that can be catalyzed, as well as new structural and mechanistic insights into these fascinating reactions. PMID:23141873

  11. Neurotoxins: Free Radical Mechanisms and Melatonin Protection

    PubMed Central

    Reiter, Russel J.; Manchester, Lucien C.; Tan, Dun-Xian

    2010-01-01

    Toxins that pass through the blood-brain barrier put neurons and glia in peril. The damage inflicted is usually a consequence of the ability of these toxic agents to induce free radical generation within cells but especially at the level of the mitochondria. The elevated production of oxygen and nitrogen-based radicals and related non-radical products leads to the oxidation of essential macromolecules including lipids, proteins and DNA. The resultant damage is referred to as oxidative and nitrosative stress and, when the molecular destruction is sufficiently severe, it causes apoptosis or necrosis of neurons and glia. Loss of brain cells compromises the functions of the central nervous system expressed as motor, sensory and cognitive deficits and psychological alterations. In this survey we summarize the publications related to the following neurotoxins and the protective actions of melatonin: aminolevulinic acid, cyanide, domoic acid, kainic acid, metals, methamphetamine, polychlorinated biphenyls, rotenone, toluene and 6-hydroxydopamine. Given the potent direct free radical scavenging activities of melatonin and its metabolites, their ability to indirectly stimulate antioxidative enzymes and their efficacy in reducing electron leakage from mitochondria, it would be expected that these molecules would protect the brain from oxidative and nitrosative molecular mutilation. The studies summarized in this review indicate that this is indeed the case, an action that is obviously assisted by the fact that melatonin readily crosses the blood brain barrier. PMID:21358970

  12. Praxis: Implication for "Really" Radical Education.

    ERIC Educational Resources Information Center

    Allman, Paula; Wallis, John

    1990-01-01

    Explicates the concept of praxis in Marx's dialectical analysis of capitalism and relates it to radical education: issues of access to educational opportunities, the challenge to the status quo through curriculum change, the role of the intellectual, and the relationship between knowledge and action. (SK)

  13. Reactive intermediates: Radicals with multiple personalities

    NASA Astrophysics Data System (ADS)

    Forbes, Malcolm D. E.

    2013-06-01

    A combined theoretical and experimental approach has revealed that radicals can be significantly stabilized by the presence of a remote anionic site in the same molecule. This finding has implications for understanding and potentially controlling the reactivity of these important reactive intermediates.

  14. Snowballing radical generation leads to ultrahigh molecular weight polymers.

    PubMed

    Laurino, Paola; Hernandez, Hugo F; Bräuer, Judith; Krüger, Kathleen; Grützmacher, Hansjörg; Tauer, Klaus; Seeberger, Peter H

    2012-10-26

    Styrene is the classical monomer obeying zero-one kinetics in radical emulsion polymerization. Accordingly, particles that are less than 100 nm in diameter contain either one or no growing radical(s). We describe a unique photoinitiated polymerization reaction accelerated by snowballing radical generation in a continuous flow reactor. Even in comparison to classical emulsion polymerization, these unprecedented snowballing reactions are rapid and high-yielding, with each particle simultaneously containing more than one growing radical. This is a consequence of photoinitiator incorporation into the nascent polymer backbone and repeated radical generation upon photo-irradiation. PMID:22837041

  15. Enzymatic production of biodiesel from microalgal oil using ethyl acetate as an acyl acceptor.

    PubMed

    Alavijeh, Razieh Shafiee; Tabandeh, Fatemeh; Tavakoli, Omid; Karkhane, Aliasghar; Shariati, Parvin

    2015-01-01

    Microalgae have become an important source of biomass for biodiesel production. In enzymatic transesterification reaction, the enzyme activity is decreased in presence of alcohols. The use of different acyl acceptors such as methyl/ethyl acetate is suggested as an alternative and effective way to overcome this problem. In this study, ethyl acetate was used for the first time in the enzymatic production of biodiesel by using microalga, Chlorella vulgaris, as a triglyceride source. Enzymatic conversion of such fatty acids to biodiesel was catalyzed by Novozym 435 as an efficient immobilized lipase which is extensively used in biodiesel production. The best conversion yield of 66.71% was obtained at the ethyl acetate to oil molar ratio of 13:1 and Novozym 435 concentration of 40%, based on the amount of oil, and a time period of 72 h at 40℃. The results showed that ethyl acetate have no adverse effect on lipase activity and the biodiesel amount was not decreased even after seven transesterification cycles, so ethyl acetate has a great potential to be substituted for short-chain alcohols in transesterification reaction. PMID:25742923

  16. Spectroscopic characterization of ethyl xanthate oxidation products and analysis by ion interaction chromatography

    PubMed

    Hao; Silvester; Senior

    2000-10-15

    An ion interaction chromatographic separation method, coupled with UV spectroscopic detection, has been developed for the analysis of ethyl xanthate (O-ethyl dithiocarbonate) and its oxidative decomposition products in mineral flotation systems. The effects of the ion-pairing agent (tetrabutylammonium ion), pH modifier (phosphoric acid), and organic modifier (acetonitrile) in the eluant upon the retention characteristics of the ethyl xanthate oxidation products have been determined. The optimized separation procedure has been successfully applied to the analysis of ethyl xanthate and its oxidation products in a nickel-iron sulfide mineral suspension containing a number of other anionic species, including cyanide complexes of nickel and iron, as well as sulfur-oxy anions. The ethyl xanthate oxidation products investigated in this study have been isolated as pure compounds and characterized by UV-visible, FT-IR, and NMR spectroscopies. The UV-visible and FT-IR spectroscopic properties of these species are discussed in terms of the chemical modifications of the thiocarbonate group. PMID:11055697

  17. Surface-enhanced Raman scattering for quantitative detection of ethyl carbamate in alcoholic beverages.

    PubMed

    Yang, Danting; Zhou, Haibo; Ying, Yibin; Niessner, Reinhard; Haisch, Christoph

    2013-11-01

    Ethyl carbamate, a by-product of fermentation and storage with widespread occurrence in fermented food and alcoholic beverages, is a compound potentially toxic to humans. In this work, a new approach for quantitative detection of ethyl carbamate in alcoholic beverages, based on surface-enhanced Raman scattering (SERS), is reported. Individual silver-coated gold nanoparticle colloids are used as SERS amplifiers, yielding high Raman enhancement of ethyl carbamate in three kinds of alcoholic beverages (vodka, Obstler, and white rum). The characteristic band at 1,003 cm(-1), which is the strongest and best reproducible peak in the SERS spectra, was used for quantitative evaluation of ethyl carbamate. The limit of detection, which corresponds to a signal-to-noise ratio of 3, was 9.0 × 10(-9) M (0.8 μg · L(-1)), 1.3 × 10(-7) M (11.6 μg · L(-1)), and 7.8 × 10(-8) M (6.9 μg · L(-1)), respectively. Surface-enhanced Raman spectroscopy offers great practical potential for the in situ assessment and identification of ethyl carbamate in the alcoholic beverage industry. PMID:24154926

  18. Antihyperglycemic effect of Hypericum perforatum ethyl acetate extract on streptozotocin-induced diabetic rats

    PubMed Central

    Arokiyaraj, S; Balamurugan, R; Augustian, P

    2011-01-01

    Objective To evaluate the antihyperglycemic activity of ethyl acetate extract of Hypericum perforatum (H. perforatum) in streptozotocin (STZ)-induced diabetic rats. Methods Acute toxicity and oral glucose tolerance test were performed in normal rats. Male albino rats were rendered diabetic by STZ (40 mg/kg, intraperitoneally). H. perforatum ethyl acetate extract was orally administered to diabetic rats at 50, 100 and 200 mg/kg doses for 15 days to determine the antihyperglycemic activity. Biochemical parameters were determined at the end of the treatment. Results H. perforatum ethyl acetate extract showed dose dependant fall in fasting blood glucose (FBG). After 30 min of extract administration, FBG was reduced significantly when compared with normal rats. H. perforatum ethyl acetate extract produced significant reduction in plasma glucose level, serum total cholesterol, triglycerides, glucose-6-phosphatase levels. Tissue glycogen content, HDL-cholesterol, glucose-6-phosphate dehydrogenase were significantly increased compared with diabetic control. No death or lethal effect was observed in the toxic study. Conclusions The results demonstrate that H. perforatum ethyl acetate extract possesses potent antihyperglycemic activity in STZ induced diabetic rats. PMID:23569798

  19. Lignin is linked to ethyl-carbamate formation in ume (Prunus mume) liqueur.

    PubMed

    Hashiguchi, Tomokazu; Izu, Hanae; Sudo, Shigetoshi

    2012-01-01

    Ethyl carbamate concentrations in oak barrel-aged ume (Prunus mume) liqueurs were measured, and possible explanations for elevated levels were examined. The average concentration was 0.30 mg/L, significantly higher than in ume liqueurs not aged in oak (0.08 mg/L). Oak powder extracts were prepared from both untoasted and toasted oak powder by extraction with aqueous ethanol, and these were used to make ume liqueurs. Relative to a no-oak control, the ethyl carbamate concentrations were 3.8 and 11 times higher in the ume liqueur made with the untoasted and toasted oak powder extracts respectively. The extracts were loaded onto a C18 column, washed with water, and eluted with methanol. The (13)C-NMR spectra for the main constituents of the methanol elution fractions were consistent with those for lignin or fragments thereof. The methanol fractions were added to ume liqueur which was stored for 3 months. Relative to a control, the ethyl carbamate concentrations in the 3-month old liqueurs were found to be 1.2 and 4.6 higher for the untoasted oak-powder and the toasted oak-powder respectively. Ethyl carbamate was formed when lignin was added to a 40% aqueous ethanol solution that contained potassium cyanide. These observations suggest that lignin or fragments thereof promote the formation of ethyl carbamate. PMID:22232267

  20. Base-Mediated Stereospecific Synthesis of Aryloxy and Amino substituted Ethyl Acrylates

    PubMed Central

    Namjoshi, Ojas A.; Verma, Ranjit; Lorenz, Michael; Tiruveedhula, V. V. N. Phani Babu; Monte, Aaron; Bertz, Steven H.

    2011-01-01

    The stereospecific synthesis of aryloxy and amino substituted E- and Z-ethyl-3-acrylates is of interest because of their potential in the polymer industry and in medicinal chemistry. During work on a copper-catalyzed cross-coupling reaction of E- and Z-ethyl-3-iodo-acrylates with phenols and N-heterocycles, we discovered a very simple (non-metallic) method for the stereospecific synthesis of aryloxy and amino substituted acrylates. To study this long standing problem on the stereoselectivity of aryloxy and amino substituted acrylates, a series of O- and N-substituted nucleophiles was allowed to react with E- and Z-ethyl-3-iodo-acrylates. Screening of different bases indicated that DABCO (1,4-diazabicyclo[2.2.2]octane) afforded successful conversion of E- and Z- ethyl-3-iodoacrylates into aryloxy and amino substituted ethyl acrylates in a stereospecific manner. Herein are the details of this DABCO-mediated stereospecific synthesis of aryloxy and amino substituted E- or Z-acrylates. PMID:22073965