Science.gov

Sample records for acids sulfonic acids

  1. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  2. Safety assessment of xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes as used in cosmetics.

    PubMed

    Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Hill, Ronald; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2011-12-01

    Xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes used in cosmetics as surfactants, hydrotropes, were reviewed in this safety assessment. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Cosmetic Ingredient Review Expert Panel reviewed relevant animal and human data related to these ingredients. The panel concluded that xylene sulfonic acid and alkyl aryl sulfonate hydrotropes are safe as cosmetic ingredients in the present practices of use and concentrations as described in this safety assessment, when formulated to be nonirritating.

  3. Acid-mediated formation of trifluoromethyl sulfonates from sulfonic acids and a hypervalent iodine trifluoromethylating agent.

    PubMed

    Koller, Raffael; Huchet, Quentin; Battaglia, Philip; Welch, Jan M; Togni, Antonio

    2009-10-28

    A variety of sulfonic acids have been trifluoromethylated using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one under mild conditions in good to excellent yields. Initial mechanistic investigations of this reaction show a clean second-order kinetics and only very weak substrate electronic effects.

  4. Affinity labelling enzymes with esters of aromatic sulfonic acids

    DOEpatents

    Wong, Show-Chu; Shaw, Elliott

    1977-01-01

    Novel esters of aromatic sulfonic acids are disclosed. The specific esters are nitrophenyl p- and m-amidinophenylmethanesulfonate. Also disclosed is a method for specific inactivation of the enzyme, thrombin, employing nitrophenyl p-amidinophenylmethanesulfonate.

  5. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  6. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  7. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  8. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  9. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  10. Hydrogen Bonding Cluster-Enabled Addition of Sulfonic Acids to Haloalkynes: Access to Both (E)- and (Z)-Alkenyl Sulfonates.

    PubMed

    Zeng, Xiaojun; Liu, Shiwen; Shi, Zhenyu; Xu, Bo

    2016-10-07

    We developed an efficient synthesis of alkenyl sulfonates via hydrogen bonding cluster-enabled addition of sulfonic acids to haloalkynes. The reactivity of sulfonic acids could be significantly enhanced in the presence of strong hydrogen bonding donors. This metal-free method results in good chemical yields for a wide range of haloalkyne substrates and demonstrates good functional group tolerance. What is more, we can control the stereoselectivity of addition (cis vs trans) by varying the steric bulk of the sulfonic acid.

  11. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  12. Phosphoric Acid-Mediated Synthesis of Vinyl Sulfones through Decarboxylative Coupling Reactions of Sodium Sulfinates with Phenylpropiolic Acids.

    PubMed

    Rong, Guangwei; Mao, Jincheng; Yan, Hong; Zheng, Yang; Zhang, Guoqi

    2015-08-07

    A novel phosphoric acid -mediated synthesis of vinyl sulfones through decarboxylative coupling reactions of sodium sulfinates with phenylpropiolic acids is described. This transformation is efficient and environmentally friendly.

  13. Identification of sulfonic acids as efficient ecto-5'-nucleotidase inhibitors.

    PubMed

    Iqbal, Jamshed; Saeed, Aamer; Raza, Rabia; Matin, Abdul; Hameed, Abdul; Furtmann, Norbert; Lecka, Joanna; Sévigny, Jean; Bajorath, Jürgen

    2013-01-01

    Ecto-5'-nucleotidase (CD73) is well known for its implication in cancer. Inhibition of ecto-5'-nucleotidases is thought to provide an attractive approach to cancer therapy. This study identifies sulfonic acid compounds as efficient inhibitors of ecto-5'-nucleotidases. The compounds were tested against recombinant human and rat ecto-5'-nucleotidases. The most potent new sulfonic acid inhibitor 6-amino-4-hydroxynaphthalene-2-sulfonic acid (1) of ecto-5'-nucleotidase had an IC₅₀ of 1.32 ± 0.09 μM for the human and 10.4 ± 3.3 μM for the rat enzyme. Generally, all compounds were more active against the human enzyme. Plausible binding mode models were developed for this new class of inhibitors. Furthermore, several sulfonic acid inhibitors were efficient cytotoxic agents when tested on H157 cancer cell lines. Hence, new ecto-5'-nucleotidases inhibitors displayed significant potential for further development as compounds for anti-cancer therapy.

  14. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst (Trifluoromethane sulfonic acid) may safely be used in the... chapter) in accordance with the following conditions: (a) The catalyst meets the following specifications... steam and water and the catalyst is removed with the aqueous phase. Final traces of catalyst are...

  15. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst (Trifluoromethane... catalyst meets the following specifications: Appearance, Clear liquid. Color, Colorless to amber... esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous...

  16. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst (Trifluoromethane... catalyst meets the following specifications: Appearance, Clear liquid. Color, Colorless to amber... esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous...

  17. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst (Trifluoromethane... catalyst meets the following specifications: Appearance, Clear liquid. Color, Colorless to amber... esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous...

  18. Aqueous Trifluoromethane Sulfonic Acid Fuel Cells.

    DTIC Science & Technology

    1981-02-01

    Development of Low Tempera- ture Acid Electrolytes," National Fuel Cell Seminar, Bethesda, MD, June 1979. 8 George, M. and Januszkiewicz , S., "New Materials...Department 2- K US Department of Energy (1) LaVerne, CA 91750 ATTN: Mr. Gary Voelker 20 Massachusetts Avenue, NW Union Carbide Corporation (1) Washington, DC

  19. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  20. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  1. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  2. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  3. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  4. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  5. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  6. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  7. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  8. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  9. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  10. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  11. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  12. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  13. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  14. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  15. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  16. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  17. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  18. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  19. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  20. 40 CFR 721.10487 - Alkylbenzenes sulfonic acids, metal salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylbenzenes sulfonic acids, metal... Specific Chemical Substances § 721.10487 Alkylbenzenes sulfonic acids, metal salts (generic). (a) Chemical... as alkylbenzenes sulfonic acids, metal salts (PMNs P-04-599, P-04-600, P-04-605, and P-04-606)...

  1. 40 CFR 721.10487 - Alkylbenzenes sulfonic acids, metal salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylbenzenes sulfonic acids, metal... Specific Chemical Substances § 721.10487 Alkylbenzenes sulfonic acids, metal salts (generic). (a) Chemical... as alkylbenzenes sulfonic acids, metal salts (PMNs P-04-599, P-04-600, P-04-605, and P-04-606)...

  2. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

    PubMed

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

    2012-11-01

    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

  3. Production of Jatropha biodiesel fuel over sulfonic acid-based solid acids.

    PubMed

    Chen, Shih-Yuan; Lao-Ubol, Supranee; Mochizuki, Takehisa; Abe, Yohko; Toba, Makoto; Yoshimura, Yuji

    2014-04-01

    Sulfonic acid-functionalized platelet SBA-15 mesoporous silica with an acid capacity of 2.44mmol H(+) g-cat(-1) (shortly termed 15SA-SBA-15-p) was one-pot synthesized by co-condensation method. When applied as solid acid catalyst in synthesis of Jatropha biodiesel fuel (BDF), the 15SA-SBA-15-p catalyst showed higher activity and resistances to water and free fatty acid (FFA) than commercial sulfonic resins of Amberlyst-15 and SAC-13. For the continuous Jatropha BDF production, a steady 75-78wt% of fatty acid methyl ester (FAME) content was obtained over 15SA-SBA-15-p catalyst at 150°C for 75h, whereas the Amberlyst-15 and SAC-13 catalysts were quickly deactivated due to the decomposition of thermally unstable framework and serious leaching of sulfonic acids. More importantly, the quality, stability and cold flow characteristic of Jatropha BDF synthesized by 15SA-SBA-15-p catalyst were better than those synthesized by Amberlyst-15 and SAC-13 catalysts, making the blending with petro-diesel an easy task.

  4. Penicillanic acid sulfone: nature of irreversible inactivation of RTEM beta-lactamase from Escherichia coli.

    PubMed

    Brenner, D G; Knowles, J R

    1984-11-20

    When penicillanic acid sulfone in large molar excess is incubated with the RTEM beta-lactamase, the enzyme becomes inactivated irreversibly. From studies of the consequential spectroscopic changes, from the use of specifically tritiated penicillanic acid sulfone, and from comparison by isoelectric focusing of the enzyme after inactivation by the sulfone and by clavulanic acid, the inactivated enzyme appears to be cross-linked by a beta-aminoacrylate fragment deriving from C-5, C-6, and C-7 of the original beta-lactam. Model studies on the behavior of alcoholic solutions of penicillanic acid sulfone in the presence of amines are entirely consistent with this interpretation.

  5. Thermochemical comparisons of homogeneous and heterogeneous acids and bases. 1. Sulfonic acid solutions and resins as prototype Broensted acids

    SciTech Connect

    Arnett, E.M.; Haaksma, R.A.; Chawla, B.; Healy, M.H.

    1986-08-06

    Heats of ionization by thermometric titration for a series of bases (or acids) can be used to compare solid acids (or bases) with liquid analogues bearing the same functionalities in homogeneous solutions. The method is demonstrated for Broensted acids by reacting a series of substituted nitrogen bases with solutions of p-toluenesulfonic acid (PTSA) in acetonitrile and with suspensions of the microporous polymeric arylsulfonic acid resin-Dowex 50W-X8 in the same solvent. Under well-controlled anhydrous conditions there is a good correlation (r = 0.992) between the heats of reaction of the bases with the homogeneous and heterogeneous acid systems, but the homogeneous system gives a more exothermic interaction by 3-4 kcal mol/sup -1/ for a series of 29 substituted pyrimidines, anilines, and some other amines. This difference may be attributed to homohydrogen bonding interactions between excess acid and sulfonate anion sites which are more restricted geometrically in the resin than in solution. Other factors which affect the enthalpy change for the acid-base interaction are the acid/base ratio, the water content of the sulfonic acid, the solvent, and the resin structure (e.g., microporous vs. macroporous). Steric hindrance in the base does not differentiate solid from homogeneous acid. In addition to the use of titration calorimetry, heats of immersion are reported for the Dowex-arylsulfonic acid resins and the Nafion-perfluorinated sulfonic acid resin in a series of basic liquids. The results are compared with each other and with those from a previous study of several varieties of coal.

  6. Re-evaluation of turbidimetry of proteins by use of aromatic sulfonic acids and chloroacetic acids.

    PubMed

    Ebina, S; Nagai, Y

    1979-02-01

    From studies on 11 different proteins (including native albumin and albumin with reduced disulfide-bridges) treated with sulfosalicylic, 2-naphthalenesulfonic, toluenesulfonic, dichloroacetic, or trichloroacetic acids, we elucidate the interactions determining the resulting turbidities and other factors affecting turbidities, and we discuss the clinical utility of such turbidimetry. At least three interactions are important in determining turbidity: reduction of positive charges on the protein, hydrogen bonding of the non-ionized chloroacetic acids with the protein, and hydrophobic interaction of the aromatic sulfonic acids with albumin. Turbidity varies appreciably with the species of acid and protein, concentrations of acid, temperature, and standing time after acid is added. We conclude that this technique should be restricted to confirming proteinuria.

  7. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  8. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  9. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  10. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  11. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  12. Bis-sulfonic acid ionic liquids for the conversion of fructose to 5-hydroxymethyl-2-furfural.

    PubMed

    Sim, Sang Eun; Kwon, Sunjeong; Koo, Sangho

    2012-10-31

    Homogenous bis-sulfonic acid ionic liquids (1 mol equiv.) in DMSO (10 mol equiv.) at 100 °C efficiently mediated the conversion of D-fructose into 5-hydroxymethyl-2-furfural in 75% isolated yield, which was roughly a 10% increment compared to the case of the mono-sulfonic acid ionic liquids.

  13. Nanostructured membranes and electrodes with sulfonic acid functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Tripathi, Bijay P.; Schieda, M.; Shahi, Vinod K.; Nunes, Suzana P.

    Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 × 10 -2 S cm -1 at 30 °C and 16.8 × 10 -2 S cm -1 at 80 °C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level.

  14. Determination of perfluoroalkyl carboxylic, sulfonic, and phosphonic acids in food.

    PubMed

    Ullah, Shahid; Alsberg, Tomas; Vestergren, Robin; Berger, Urs

    2012-11-01

    A sensitive and accurate method was developed and validated for simultaneous analysis of perfluoroalkyl carboxylic acids, sulfonic acids, and phosphonic acids (PFPAs) at low picograms per gram concentrations in a variety of food matrices. The method employed extraction with acetonitrile/water and cleanup on a mixed-mode co-polymeric sorbent (C8 + quaternary amine) using solid-phase extraction. High-performance liquid chromatographic separation was achieved on a C18 column using a mobile phase gradient containing 5 mM 1-methyl piperidine for optimal chromatographic resolution of PFPAs. A quadrupole time-of-flight high-resolution mass spectrometer operating in negative ion mode was used as detector. Method detection limits were in the range of 0.002 to 0.02 ng g(-1) for all analytes. Sample preparation (extraction and cleanup) recoveries at a spiking level of 0.1 ng g(-1) to a baby food composite were in the range of 59 to 98 %. A strong matrix effect was observed in the analysis of PFPAs in food extracts, which was tentatively assigned to sorption of PFPAs to the injection vial in the solvent-based calibration standard. The method was successfully applied to a range of different food matrices including duplicate diet samples, vegetables, meat, and fish samples.

  15. Rh(III)-catalyzed synthesis of sultones through C-H activation directed by a sulfonic acid group.

    PubMed

    Qi, Zisong; Wang, Mei; Li, Xingwei

    2014-09-04

    A new rhodium-catalyzed synthesis of sultones via the oxidative coupling of sulfonic acids with internal alkynes is described. The reaction proceeds via aryl C-H activation assisted by a sulfonic acid group.

  16. Accumulation potentials of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays).

    PubMed

    Krippner, Johanna; Falk, Sandy; Brunn, Hubertus; Georgii, Sebastian; Schubert, Sven; Stahl, Thorsten

    2015-04-15

    Uptake of perfluoroalkyl acids (PFAAs) by maize represents a potential source of exposure for humans, either directly or indirectly via feed for animals raised for human consumption. The aim of the following study was, therefore, to determine the accumulation potential of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays). Two different concentrations of PFAAs were applied as aqueous solution to the soil to attain target concentrations of 0.25 mg or 1.00 mg of PFAA per kg of soil. Maize was grown in pots, and after harvesting, PFAA concentrations were measured in the straw and kernels of maize. PFCA and PFSA concentrations of straw decreased significantly with increasing chain length. In maize kernels, only PFCAs with a chain length ≤ C8 as well as perfluorobutanesulfonic acid (PFBS) were detected. The highest soil-to-plant transfer for both straw and kernels was determined for short-chained PFCAs and PFSAs.

  17. Silica-supported sulfonic acids as recyclable catalyst for esterification of levulinic acid with stoichiometric amounts of alcohols.

    PubMed

    Maggi, Raimondo; Shiju, N Raveendran; Santacroce, Veronica; Maestri, Giovanni; Bigi, Franca; Rothenberg, Gadi

    2016-01-01

    Converting biomass into value-added chemicals holds the key to sustainable long-term carbon resource management. In this context, levulinic acid, which is easily obtained from cellulose, is valuable since it can be transformed into a variety of industrially relevant fine chemicals. Here we present a simple protocol for the selective esterification of levulinic acid using solid acid catalysts. Silica supported sulfonic acid catalysts operate under mild conditions and give good conversion and selectivity with stoichiometric amounts of alcohols. The sulfonic acid groups are tethered to the support using organic tethers. These tethers may help in preventing the deactivation of the active sites in the presence of water.

  18. Silica-supported sulfonic acids as recyclable catalyst for esterification of levulinic acid with stoichiometric amounts of alcohols

    PubMed Central

    Santacroce, Veronica; Maestri, Giovanni; Bigi, Franca; Rothenberg, Gadi

    2016-01-01

    Summary Converting biomass into value-added chemicals holds the key to sustainable long-term carbon resource management. In this context, levulinic acid, which is easily obtained from cellulose, is valuable since it can be transformed into a variety of industrially relevant fine chemicals. Here we present a simple protocol for the selective esterification of levulinic acid using solid acid catalysts. Silica supported sulfonic acid catalysts operate under mild conditions and give good conversion and selectivity with stoichiometric amounts of alcohols. The sulfonic acid groups are tethered to the support using organic tethers. These tethers may help in preventing the deactivation of the active sites in the presence of water. PMID:27829924

  19. [New synthesis of the anticoagulant pentasaccharide idraparinux and preparation of its analogues containing sulfonic acid moieties].

    PubMed

    Herczeg, Mihály

    2012-01-01

    Two novel synthetic pathways were elaborated for the preparation of idraparinux, a heparin-related fully O-sulfated, O-methylated anticoagulant pentasaccharide. Both methods based upon a [2+3] block synthesis utilizing the same trisaccharide acceptor which was coupled to either a uronic acid disaccharide donor or its nonoxidized precursor. Two bioisosteric sulfonic acid analogues of idraparinux were also prepared, in which two or three primary sulfate esters were replaced by sodium-sulfonatomethyl moieties. The sulfonic acid groups were formed on a monosaccharide level and the obtained carbohydrate sulfonic acid esters were found to be excellent donors and acceptors in the glycosylation reactions. The disulfonic-acid analogue was prepared in a [2+3] block synthesis by using a trisaccharide disulfonic acid as an acceptor and a glucuronide disaccharide as a donor. For the synthesis of the pentasaccharide trisulfonic acid, a more-efficient approach, which involved elongation of the trisaccharide acceptor with a non-oxidized precursor of the glucuronic acid followed by post-glycosidation oxidation at the tetrasaccharide level and a subsequent [1+4] coupling reaction, was elaborated. In vitro evaluation of the anticoagulant activity of the reference compound idraparinux and the new sulfonic acid derivatives revealed that the disulfonate analogue inhibited the blood-coagulation-proteinase factor Xa with outstanding efficacy; however, the introduction of the third sulfonic acid moiety resulted in a notable decrease in the anti-Xa activity.

  20. Cationic and radical intermediates in the acid photorelease from aryl sulfonates and phosphates.

    PubMed

    Terpolilli, Marco; Merli, Daniele; Protti, Stefano; Dichiarante, Valentina; Fagnoni, Maurizio; Albini, Angelo

    2011-01-01

    The irradiation of a series of phenyl sulfonates and phosphates leads to the quantitative release of acidity with a reasonable quantum yield (≈0.2). Products characterization, ion chromatography analysis and potentiometric titration are consistent with the intervening of two different paths in this reaction, viz. cationic with phosphates and (mainly) radical with sulfonates.

  1. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination from textiles.

    PubMed

    Supreeyasunthorn, Phenpimuk; Boontanon, Suwanna K; Boontanon, Narin

    2016-01-01

    The goals of this study were to determine the concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in textiles and to determine PFOS and PFOA contamination in textile washing water. Quantification analysis was performed by high performance liquid chromatography coupled with tandem mass spectrometry. Analysis of 32 textile samples by methanol extraction revealed that the average concentrations of PFOS and PFOA were 0.18 µg m(-2) (0.02 to 0.61 µg m(-2)) and 2.74 µg m(-2) (0.31 to 14.14 µg m(-2)), respectively. Although the average concentration of PFOS found in textile samples was below European Union (EU) Commission regulations (<1 µg m(-2)), the average concentration of PFOA was 2.74 µg m(-2), and 68.75% of textile samples had PFOA concentrations exceeding 1 µg m(-2). Thus, based on these results, the concentration of PFOA in products should also be regulated. Experiments on PFOS and PFOA leaching into washing water were conducted. The maximum concentrations of PFOS and PFOA were measured after the first washing; the concentrations gradually decreased with each subsequent washing. PFOS and PFOA migrated from textiles and were released into the environment, with disappearance percentages of 29.8% for PFOS and 99% for PFOA. The data presented in this study showed that textiles could be a significant direct and indirect source of PFOS and PFOA exposure for both humans and the environment.

  2. Titania-based molecularly imprinted polymer for sulfonic acid dyes prepared by sol-gel method.

    PubMed

    Li, Man; Li, Rong; Tan, Jin; Jiang, Zi-Tao

    2013-03-30

    A novel titania-based molecularly imprinted polymer (MIP) was synthesized through sol-gel process with sunset yellow (Sun) as template, without use of functional monomer. MIP was used as a solid-phase extraction material for the isolation and enrichment of sulfonic acid dyes in beverages. The results showed that MIP exhibited better selectivity, higher recovery and adsorption capacity for the sulfonic acid dyes compared to the non-imprinted polymer (NIP). MIP presented highest extraction selectivity to Sun when pH less than or equal to 3. The adsorption capacity was 485.9 mg g(-1), which was larger than that of NIP (384.7 mg g(-1)). The better clean-up ability demonstrated the capability of MIP for the isolation and enrichment of sulfonic acid dyes in complicated food samples. The mean recoveries for the sulfonic acid dyes on MIP were from 81.9% to 97.2% in spiked soft drink.

  3. Magnetite-supported sulfonic acid: a retrievable nanocatalyst for the Ritter reaction and multicomponent reactions

    EPA Science Inventory

    Magnetite-sulfonic acid (NanocatFe-OSO3H), prepared by wet-impregnation method, serves as a magnetically retrievable sustainable catalyst for the Ritter reaction which can be used in several reaction cycles without any loss of activity.

  4. [Investigation on formation mechanism of secologanic acid sulfonates in sulfur-fumigated buds of Lonicera japonica].

    PubMed

    Guo, Ai-Li; Gao, Hui-Min; Chen, Liang-Mian; Zhang, Qi-Wei; Wang, Zhi-Min

    2014-05-01

    To investigate formation mechanism of secologanic acid sulfonates in sulfur-fumigated buds of Lonicera japonica, secologanic acid was enriched and purified from the sun-dried buds of L. japonica by various column chromatography on macroporus resin HPD-100, silica gel and ODS. The stimulation experiments of sulfur-fumigation process were carried out using secologanic acid reacted with SO2 in the aqueous solution. The reaction mechanism could be involved in the esterification or addition reaction. The present investigation provides substantial evidences for interpreting formation pathway of secologanic acid sulfonates in sulfur-fumigated buds of L. japonica.

  5. Esterification free fatty acid in palm fatty acid distillate using sulfonated rice husk ash catalyst

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Sutrisno, Bachrun

    2017-01-01

    Indonesia, as one of the biggest palm oil producers and exporters in the world, is producing large amounts of low-grade oil such as Palm Fatty Acid Distillate (PFAD) from palm oil industries. The use of PFAD can reduce the cost of biodiesel production significantly, which makes PFAD a highly potential alternative feedstock for biodiesel production. In this paper, the esterification of free fatty acid (FFA) on PFAD was studied using rice husk ash (RHA) as heterogeneous catalyst. The rice husk ash catalyst was synthesized by sulfonation using concentrated sulfuric acid. The RHA catalyst were characterized by using different techniques, such as porosity analysis, Fourier transform infrared (FT-IR) spectroscopy, total number of acid sites and elemental analysis. The effects of the molar ratio of methanol to PFAD (1-10%), the molar ratio of methanol to PFAD (4:1-10:1), and the reaction temperature (40-60°C) were studied for the conversion of FFA to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 10:1, the catalyst amount of 10 wt% of PFAD, and reaction temperature of 60°C.

  6. A Modular Synthetic Approach to Isosteric Sulfonic Acid Analogues of the Anticoagulant Pentasaccharide Idraparinux.

    PubMed

    Mező, Erika; Eszenyi, Dániel; Varga, Eszter; Herczeg, Mihály; Borbás, Anikó

    2016-11-11

    Heparin-based anticoagulants are drugs of choice in the therapy and prophylaxis of thromboembolic diseases. Idraparinux is a synthetic anticoagulant pentasaccharide based on the heparin antithrombin-binding domain. In the frame of our ongoing research aimed at the synthesis of sulfonic acid-containing heparinoid anticoagulants, we elaborated a modular pathway to obtain a series of idraparinux-analogue pentasaccharides bearing one or two primary sulfonic acid moieties. Five protected pentasaccharides with different C-sulfonation patterns were prepared by two subsequent glycosylation reactions, respectively, using two monosaccharide and four disaccharide building blocks. Transformation of the protected derivatives into the fully O-sulfated, O-methylated sulfonic acid end-products was also studied.

  7. Hierarchical Porous Interlocked Polymeric Microcapsules: Sulfonic Acid Functionalization as Acid Catalysts

    PubMed Central

    Wang, Xiaomei; Gu, Jinyan; Tian, Lei; Zhang, Xu

    2017-01-01

    Owing to their unique structural and surface properties, mesoporous microspheres are widely applied in the catalytic field. Generally, increasing the surface area of the specific active phase of the catalyst is a good method, which can achieve a higher catalytic activity through the fabrication of the corresponding catalytic microspheres with the smaller size and hollow structure. However, one of the major challenges in the use of hollow microspheres (microcapsules) as catalysts is their chemical and structural stability. Herein, the grape-like hypercrosslinked polystyrene hierarchical porous interlocked microcapsule (HPIM-HCL-PS) is fabricated by SiO2 colloidal crystals templates, whose structure is the combination of open mouthed structure, mesoporous nanostructure and interlocked architecture. Numerous microcapsules assembling together and forming the roughly grape-like microcapsule aggregates can enhance the structural stability and recyclability of these microcapsules. After undergoing the sulfonation, the sulfonated HPIM-HCL-PS is served as recyclable acid catalyst for condensation reaction between benzaldehyde and ethylene glycol (TOF = 793 h−1), moreover, exhibits superior activity, selectivity and recyclability. PMID:28300062

  8. Hierarchical Porous Interlocked Polymeric Microcapsules: Sulfonic Acid Functionalization as Acid Catalysts

    NASA Astrophysics Data System (ADS)

    Wang, Xiaomei; Gu, Jinyan; Tian, Lei; Zhang, Xu

    2017-03-01

    Owing to their unique structural and surface properties, mesoporous microspheres are widely applied in the catalytic field. Generally, increasing the surface area of the specific active phase of the catalyst is a good method, which can achieve a higher catalytic activity through the fabrication of the corresponding catalytic microspheres with the smaller size and hollow structure. However, one of the major challenges in the use of hollow microspheres (microcapsules) as catalysts is their chemical and structural stability. Herein, the grape-like hypercrosslinked polystyrene hierarchical porous interlocked microcapsule (HPIM-HCL-PS) is fabricated by SiO2 colloidal crystals templates, whose structure is the combination of open mouthed structure, mesoporous nanostructure and interlocked architecture. Numerous microcapsules assembling together and forming the roughly grape-like microcapsule aggregates can enhance the structural stability and recyclability of these microcapsules. After undergoing the sulfonation, the sulfonated HPIM-HCL-PS is served as recyclable acid catalyst for condensation reaction between benzaldehyde and ethylene glycol (TOF = 793 h‑1), moreover, exhibits superior activity, selectivity and recyclability.

  9. Camphorquinone-10-sulfonic acid and derivatives: convenient reagents for reversible modification of arginine residues

    SciTech Connect

    Pande, C.S.; Pelzig, M.; Glass, J.D.

    1980-02-01

    Camphorquinone-10-sulfonic acid hydrate was prepared by the action of selenous acid on camphor-10-sulfonic acid. Camphorquinone-10-sulfonylnorleucine was prepared either from the sulfonic acid via the sulfonyl chloride or by selenous acid oxidation of camphor-10-sulfonylnorleucine. These reagents are useful for specific, reversible modification of the guanidino groups of arginine residues. Camphorquinonsulfonic acid is a crystalline water-soluble reagent that is especially suitable for use with small arginine-containing molecules, because the sulfonic acid group of the reagent is a convenient handle for analytical and preparative separation of products. Camphorquinonesulfonylnorleucine is more useful for work with large polypeptides and proteins, because hydrolysates of modified proteins may be analyzed for norleucine to determine the extent of arginine modification. The adducts of the camphorquinone derivatives with the guanidino group are stable to 0.5 M hydroxylamine solutions at pH 7, the recommended conditions for cleavage of the corresponding cyclohexanedione adducts. At pH 8-9 the adducts of the camphorquinone derivatives with the guanidino group are cleaved by o-phenylenediamine. The modification and regeneration of arginine, of the dipeptide arginylaspartic acid, of ribonuclease S-peptide, and of soybean trypsin inhibitor are presented as demonstrations of the use of the reagents.The use of camphorquinonesulfonyl chloride to prepare polymers containing arginine-specific ligands is discussed.

  10. Chiral separation of metolachlor ethane sulfonic acid as a groundwater dating tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have studied the hydrologic fate of metolachlor and its two predominant metabolites, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid, in groundwater and base flows of streams for several years. These two metabolites are excellent markers for groundwater processes related to...

  11. Using chiral identification of metolachlor ethane sulfonic acid as a groundwater dating tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have studied the hydrologic fate of metolachlor and its two predominant metabolites, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid, in groundwater and base flows of streams for several years. These two metabolites are excellent markers for groundwater processes related to...

  12. Effective and selective bisphenol A synthesis on a layered silicate with spatially arranged sulfonic acid.

    PubMed

    Ide, Yusuke; Kagawa, Noriko; Itakura, Masaya; Imae, Ichiro; Sadakane, Masahiro; Sano, Tsuneji

    2012-04-01

    The silylated derivatives of a layered alkali silicate, magadiite, modified with propylsulfonic or arylsulfonic acid were synthesized and used as catalysts for an acid-catalyzed condensation of phenol with acetone. The propylsulfonated magadiites with a different amount of the attached silyl group were synthesized by the silylation of the dodecylammonium-exchanged magadiite with the tuned amount of 3-(mercaptopropyl)trimethoxysilane and the subsequent oxidation of the attached thiol to sulfonic acid. The arylsulfonated magadiite was synthesized by the silylation of the dodecylammonium-exchanged magadiite with 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane and the subsequent hydrolysis of the attached sulfonyl chloride to sulfonic acid. The X-ray diffraction (XRD) patterns and elemental mappings of the products, and the photoluminescent spectra of the Eu(3+)-exchanged products suggested that propylsulfonic or arylsulfonic acid was homogeneously distributed in the interlayer space. When all the sulfonated materials were used as an acid catalyst for condensation between phenol and acetone, p,p' bisphenol A selectively formed over the o,p' isomer, and higher yield and selectivity were attained on the catalysts with larger amount of the attached sulfonic acid. When the interlayer space of the propylsulfonated magadiite was expanded by the co-attachment of octadecylsilyl group, lower selectivity was obtained. The arylsulfonated magadiite showed considerably higher p,p' bisphenol A yield than the propylsulfonated magadiites.

  13. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato

    2001-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  14. Bifunctional phenyl monophosphonic/sulfonic acid ion exchange resin and process for using the same

    DOEpatents

    Alexandratos, Spiro; Shelley, Christopher A.; Horwitz, E. Philip; Chiarizia, Renato; Gula, Michael J.; Xue, Sui; Harvey, James T.

    2002-01-01

    A cross-linked water-insoluble ion exchange resin comprised of polymerized monomers having a phenyl ring is disclosed. A contemplated resin contains (i) polymerized phenyl ring-containing monomers having a phosphonic acid ligand linked to the phenyl ring, (ii) about 2 to about 5 millimoles per gram (mmol/g) of phosphorus as phosphonic acid ligands, and (iii) a sufficient amount of a sulfonic acid ligand such that the ratio of mmol/g of phosphonic acid to mmol/g sulfonic acid is up to 3:1. A process for removing polyvalent metal cations from aqueous solution, and a process for removing iron(III) cations from acidic copper(II) cation-containing solutions that utilize the contemplated resin or other resins are disclosed.

  15. Diffusion Coefficient of Tin(II) Methanesulfonate in Ionic Liquid and Methane Sulfonic Acid (MSA) Solvent

    NASA Astrophysics Data System (ADS)

    Yang, Kok Kee; Mahmoudian, M. R.; Ebadi, Mehdi; Koay, Hun Lee; Basirun, Wan Jeffrey

    2011-12-01

    Voltammetry and chronoamperometry for the electrodeposition of tin from Tin(II) methane sulfonate mixed with ionic liquid and methane sulfonate acid at room temperature was studied. Cyclic voltammetry shows redox waves of Tin(II), which proves that the electrodeposition of tin from Tin(II) methane sulfonate is a diffusion-controlled process. The diffusion coefficient of Tin(II) ions in the solvent mixture showed good agreement from both voltammetry and chronoamperometry results. The diffusion coefficient of Tin(II) in the mixture was much smaller than in aqueous solution, and it depends on the anion of the ionic liquid.

  16. Preparation and Characterization of Sulfonic Acid Functionalized Silica and Its Application for the Esterification of Ethanol and Maleic Acid

    NASA Astrophysics Data System (ADS)

    Sirsam, Rajkumar; Usmani, Ghayas

    2016-04-01

    The surface of commercially available silica gel, 60-200 mesh size, was modified with sulfonic acid through surface activation, grafting of 3-Mercaptopropyltrimethoxysilane, oxidation and acidification of 3-Mercaptopropylsilica. Sulfonic Acid Functionalization of Silica (SAFS) was confirmed by Fourier Transform Infra-red (FTIR) spectroscopy and thermal gravimetric analysis. Acid-base titration was used to estimate the cation exchange capacity of the SAFS. Catalytic activity of SAFS was judged for the esterification of ethanol with maleic acid. An effect of different process parameters viz. molar ratio, catalyst loading, speed of agitation and temperature were studied and optimized by Box Behnken Design (BBD) of Response Surface Methodology (RSM). Quadratic model developed by BBD-RSM reasonably satisfied an experimental and predicted values with correlation coefficient value R2 = 0.9504.

  17. Electroactive self-doped poly(amic acid) with oligoaniline and sulfonic acid groups: synthesis and electrochemical properties.

    PubMed

    Chi, Maoqiang; Wang, Shutao; Liang, Yuan; Chao, Danming; Wang, Ce

    2014-06-01

    A novel poly(amic acid) with pendant aniline tetramer and sulfonic acid groups (ESPAA) was synthesized by ternary polymerization and characterized by Fourier-transform infrared spectra, ((1))H NMR and gel permeation chromatography. The polymer showed good thermal stability and excellent solubility in the common organic solvents. The electrochemical properties were investigated carefully on a CHI 660A Electrochemical Workstation. The polymer displayed good electroactivity in acid, neutral and even in alkaline solutions (pH=1-10) due to the self-doping effect between aniline tetramer and sulfonic/carboxylic acid groups. It also exhibited satisfactory electrochromic performance with high contrast value, acceptable coloration efficiency and fast switching time in the range of pH=1-9.

  18. Nuclear Magnetic Resonance Identification of New Sulfonic Acid Metabolites of Chloroacetanilide Herbicides

    USGS Publications Warehouse

    Morton, M.D.; Walters, F.H.; Aga, D.S.; Thurman, E.M.; Larive, C.K.

    1997-01-01

    The detection of the sulfonic acid metabolites of the chloroacetanilide herbicides acetochlor, alachlor, butachlor, propachlor, and, more recently, metolachlor in surface and ground water suggests that a common mechanism for dechlorination exists via the glutathione conjugation pathway. The identification of these herbicides and their metabolites is important due to growing public awareness and concern about pesticide levels in drinking water. Although these herbicides are regulated, little is known about the fate of their metabolites in soil. The sulfonic acid metabolites were synthesized by reaction of the parent compounds with an excess of sodium sulfite. Acetochlor, alachlor, butachlor, metolachlor, and propachlor and their sulfonic acid metabolites were studied by nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. This paper provides a direct method for the preparation and characterization of these compounds that will be useful in the analysis and study of chloracetanilide herbicides and their metabolites.

  19. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    SciTech Connect

    Chang, Binbin Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

    2015-01-15

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl{sub 2} using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl{sub 2} at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of –SO{sub 3}H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N{sub 2} adsorption–desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of –SO{sub 3}H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of –SO{sub 3}H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and –SO{sub 3}H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles. - Graphical abstract: Sulfonated porous carbon nanospheres with high surface area and superior catalytic performance were prepared by a facile chemical activation route. - Highlights: • Porous carbon spheres solid acid prepared by a facile chemical activation. • It owns high surface area, superior porosity and uniform spherical morphology. • It possesses

  20. Characteristic constants of 2,2',4'-trihydroxyazobenzene-5-sulfonic acid, a reagent for spectrophotometric analysis

    USGS Publications Warehouse

    Fletcher, Mary H.

    1960-01-01

    The dye 2,2',4'-trihydroxyazobenzene-5-sulfonic acid, has shown promise as a reagent for the determination of zirconium. As the literature contains very little information about this dye, basic data pertinent to its use as a reagent were determined. The sulfonic acid group and all three of the hydroxy groups show acidic characteristics. Apparent dissociation constants were determined for the three more labile protons and the approximate order of magnitude for the fourth constant was estimated. Absorption spectra for the different ionization species are given. A curve is also included which shows the fraction of dye in the different ionization forms at acidities from 10.35M hydrochloric acid to pH 11.9. A sixth dye species was found in 1.0 to 8.4M potassium hydroxide solutions, but its nature is unknown.

  1. Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

    SciTech Connect

    Ames, Richard L.

    2004-09-01

    Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate counterparts of similar thickness

  2. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    NASA Astrophysics Data System (ADS)

    Chang, Binbin; Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

    2015-01-01

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl2 using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl2 at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of -SO3H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N2 adsorption-desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of -SO3H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of -SO3H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and -SO3H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles.

  3. Reaction kinetics of free fatty acids esterification in palm fatty acid distillate using coconut shell biochar sulfonated catalyst

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Rochmadi, Wijaya, Karna; Budiman, Arief

    2015-12-01

    Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Distillate (PFAD) with methanol, using coconut shell biochar sulfonated catalyst from biomass wastes as catalyst, were studied. In this study, the coconut shell biochar sulfonated catalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The kinetics of free fatty acid (FFA) esterification in PFAD using a coconut shell biochar sulfonated catalyst was also studied. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%w, and reaction temperature of 60°C. The proposed kinetic model shows a reversible second order reaction and represents all the experimental data satisfactorily, providing deeper insight into the kinetics of the reaction.

  4. Synthesis of new sulfonylamido-penicillanic acid sulfones inhibitors of beta-lactamases.

    PubMed

    Vanwetswinkel, S; Fastrez, J; Marchand-Brynaert, J

    1994-09-01

    Three new sulfonylamido-penicillanic acid sulfones have been prepared by reaction of 6-aminopenicillanic esters with the monoester or monoamide derivatives obtained in nucleophilic substitution reactions by alcohol or aniline on the carboxyl chloride function of sulfoacetic dichloride followed by oxidation. These penicillin sulfones are converted to beta-lactamases suicide inhibitors by removal of the C3 ester protecting group. This synthetic strategy can give access to sulfonamidopenam sulfones bearing a variety of 6-amino side chain. These inhibitors inactivate the RTEM beta-lactamase rapidly. The kinetics of inactivation are consistent with the partitioning of an acylenzyme intermediate between two main pathways: regeneration of free enzyme and irreversible inactivation, little transient inactivation is observed. A slow inhibition by the product of enzymatic hydrolysis of the sulfones is also observed.

  5. A new sesquiterpene lactone with sulfonic acid group from Saussurea lappa.

    PubMed

    Yin, Hong-Quan; Hua, Hui-Ming; Fu, Hong-Wei; Qi, Xiu-Lan; Li, Wen; Sha, Yi; Pei, Yue-Hu

    2007-01-01

    A new sesquiterpene lactone with an unusual sulfonic acid group, 13-sulfo-dihydrodehydrocostus lactone (1), was isolated from the roots of Saussurea lappa C. (Compositae), together with a known lignan (2). The structure of 1 was characterized on the basis of spectral evidence including 2DNMR studies. Compound 2 was obtained from this plant for the first time.

  6. Two new sesquiterpene lactones with the sulfonic acid group from Saussurea lappa.

    PubMed

    Yin, Hong-quan; Fu, Hong-wei; Hua, Hui-ming; Qi, Xiu-lan; Li, Wen; Sha, Yi; Pei, Yue-hu

    2005-07-01

    Two new sesquiterpene lactones with the unusual sulfonic acid group, 13-sulfo-dihydrosantamarine (1) and 13-sulfo-dihydroreynosin (2), have been isolated from the roots of Saussurea lappa C. Their structures, including the absolute configurations, were elucidated by spectroscopic methods.

  7. POLYSTYRENE SULFONIC ACID CATALYZED GREENER SYNTHESIS OF HYDRAZONES IN AQUEOUS MEDIUM USING MICROWAVES

    EPA Science Inventory

    An environmentally benign aqueous protocol for the synthesis of cyclic, bi-cyclic, and heterocyclic hydrazones using polystyrene sulfonic acid (PSSA) as a catalyst has been developed; the simple reaction proceeds efficiently in water in the absence of any organic solvent under mi...

  8. Azadirachta indica Attenuates Colonic Mucosal Damage in Experimental Colitis Induced by Trinitrobenzene Sulfonic Acid

    PubMed Central

    Gautam, M. K.; Goel, Shalini; Ghatule, R. R.; Singh, A.; Joshi, V. K.; Goel, R. K.

    2013-01-01

    Azadirachta indica leaves indicated the presence of active principles with proven antioxidants, antiinflammatory, immunomodulatory, free radical scavenging and healing properties. In the present study we evaluated the healing effects of 50% ethanol extract of dried leaves of Azadirachta indica on trinitrobenzene sulfonic acid-induced colitis in rats. Azadirachta indica extract (500 mg/kg) was administered orally, once daily for 14 days and studied for its effects on diarrhoea, food and water intake, body weight changes, colonic damage and inflammation, histology, antibacterial activity and free radicals (nitric oxide and lipid peroxidation), antioxidants (superoxide dismutase, catalase and reduced glutathione) and myeloperoxidase activities in colonic tissue. Intracolonic trinitrobenzene sulfonic acid increased colonic mucosal damage and inflammation, diarrhea, but decreased body weight which were reversed by Azadirachta indica extract and sulfasalazine (positive control) treatments. Azadirachta indica extract showed antibacterial activity. Azadirachta indica extract and sulfasalazine enhanced the antioxidants but decreased free radicals and myeloperoxidase activities affected in trinitrobenzene sulfonic acid-induced colitis. Azadirachta indica extract, thus seemed to be effective in healing trinitrobenzene sulfonic acid-induced colitis in rats. PMID:24403663

  9. From thiol to sulfonic acid: modeling the oxidation pathway of protein thiols by hydrogen peroxide.

    PubMed

    van Bergen, Laura A H; Roos, Goedele; De Proft, Frank

    2014-08-07

    Hydrogen peroxide is a natural oxidant that can oxidize protein thiols (RSH) via sulfenic acid (RSOH) and sulfinic acid (RSO2H) to sulfonic acid (RSO3H). In this paper, we study the complete anionic and neutral oxidation pathway from thiol to sulfonic acid. Reaction barriers and reaction free energies for all three oxidation steps are computed, both for the isolated substrates and for the substrates in the presence of different model ligands (CH4, H2O, NH3) mimicking the enzymatic environment. We found for all three barriers that the anionic thiolate is more reactive than the neutral thiol. However, the assistance of the environment in the neutral pathway in a solvent-assisted proton-exchange (SAPE) mechanism can lower the reaction barrier noticeably. Polar ligands can decrease the reaction barriers, whereas apolar ligands do not influence the barrier heights. The same holds for the reaction energies: they decrease (become more negative) in the presence of polar ligands whereas apolar ligands do not have an influence. The consistently negative consecutive reaction energies for the oxidation in the anionic pathway when going from thiolate over sulfenic and sulfinic acid to sulfonic acid are in agreement with biological reversibility.

  10. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst (Trifluoromethane sulfonic... catalyst meets the following specifications: Appearance, Clear liquid. Color, Colorless to amber... esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous...

  11. Copoly(arlene ether)s containing pendant sulfonic acid groups as proton exchange membrane

    SciTech Connect

    Kim, Yu Seung; Kim, Dae Sik; Robertson, Gilles; Guiver, Michael

    2008-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The P AE and PAEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2-phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. The sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sP AE and sP AEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (DS) of 1.0 had high ion exchange capacities (IEC{sub v}(wet) (volume-based, wet state)) of 1.77 and 2.55 meq./cm{sup 3}, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5-51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the area of outstanding properties in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based). Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  12. Vacuum thermal evaporation of polyaniline doped with camphor sulfonic acid

    SciTech Connect

    Boyne, Devon; Menegazzo, Nicola; Pupillo, Rachel C.; Rosenthal, Joel; Booksh, Karl S.

    2015-05-15

    Intrinsically conducting polymers belong to a class of organic polymers with intriguing electronic and physical properties specifically for electro-optical applications. Significant interest into doped polyaniline (PAni) can be attributed to its high conductivity and environmental stability. Poor dissolution in most solvents has thus far hindered the successful integration of PAni into commercial applications, which in turn, has led to the investigations of various deposition and acidic doping methods. Physical vapor deposition methods, including D.C. magnetron sputtering and vacuum thermal evaporation, have shown exceptional control over physical film properties (thickness and morphology). However, resulting films are less conductive than films deposited by conventional methods (i.e., spin and drop casting) due to interruption of the hyperconjugation of polymer chains. Specifically, vacuum thermal evaporation requires a postdoping process, which results in incorporation of impurities and oxidation of surface moieties. In this contribution, thermally evaporated films, sequentially doped by vacuum evaporation of an organic acid (camphorsulfonic acid, CSA) is explored. Spectroscopic evidence confirms the successful doping of PAni with CSA while physical characterization (atomic force microscopy) suggests films retain good morphology and are not damaged by the doping process. The procedure presented herein also combines other postpreparation methods in an attempt to improve conductivity and/or substrate adhesion.

  13. Perfluorobutane sulfonic acid hydration and interactions with O2 adsorbed on Pt3.

    PubMed

    Yan, Liuming; Balbuena, Perla B; Seminario, Jorge M

    2006-04-06

    The side chain of NAFION, a proton conductive membrane used as electrolyte in low-temperature fuel cells, is modeled with perfluorobutane sulfonic acid. Density functional theory is used to characterize structures and energetics of hydration of the model system interacting with a proton solvated with up to 24 water molecules and analyze interactions of some of these hydrated complexes with O(2) adsorbed on Pt(3). It is found that at least three water molecules are needed to ionize the sulfonic acid, and higher degrees of hydration induce the formation of cages where the water molecules are held together via complex hydrogen-bond networks. The interaction between the complex formed by the ionized acid and the hydrated proton, in contact with a bridge-adsorbed O(2)-Pt(3), promotes the protonation of the adsorbed O(2). Upon protonation, the O(2)-Pt(3) system evolves from hydrophobic to hydrophilic behavior, which may facilitate further interfacial contact.

  14. Synthesis of a sulfonic acid mimetic of the sulfated Lewis A pentasaccharide.

    PubMed

    Jakab, Zsolt; Fekete, Anikó; Csávás, Magdolna; Borbás, Anikó; Lipták, András; Antus, Sándor

    2012-03-01

    The first sulfonic acid mimetic of the sulfated Lewis A pentasaccharide in which the natural L-fucose unit is replaced by a D-arabinose ring was synthesized. Formation of the sulfonic acid moiety at a pentasaccharide level could be successfully achieved by means of introduction of an acetylthio moiety into the terminal D-galactose residue and subsequent oxidation. The equatorial arrangement of the acetylthio group linked to C-3 of the galactose ring could be obtained by double nucleophilic substitutions; efficient formation of the gulo-triflate derivatives required low-power microwave (MW) activation. Oxidation of the acetylthio group was carried out using Oxone in the presence of acetic acid.

  15. Ruthenium(II)-catalyzed oxidative C-H alkenylations of sulfonic acids, sulfonyl chlorides and sulfonamides.

    PubMed

    Ma, Wenbo; Mei, Ruhuai; Tenti, Giammarco; Ackermann, Lutz

    2014-11-10

    Twofold C-H functionalization of aromatic sulfonic acids was achieved with an in situ generated ruthenium(II) catalyst. The optimized cross-dehydrogenative alkenylation protocol proved applicable to differently substituted arenes and a variety of alkenes, including vinyl arenes, sulfones, nitriles and ketones. The robustness of the ruthenium(II) catalyst was demonstrated by the chemoselective oxidative olefination of sulfonamides as well as sulfonyl chlorides. Mechanistic studies provided support for a reversible, acetate-assisted C-H ruthenation, along with a subsequent olefin insertion.

  16. Radiation synthesis of eco-friendly water reducing sulfonated starch/acrylic acid hydrogel designed for cement industry

    NASA Astrophysics Data System (ADS)

    Abd El-Rehim, H. A.; Hegazy, El-Sayed A.; Diaa, D. A.

    2013-04-01

    Starch was treated with chlorosulfonic acid to obtain sulfonated starch. Acrylic acid/sulfonated starch semi-interpenetrated network IPN of different compositions was prepared using ionizing radiation. Swelling of prepared IPNs at different environmental conditions was studied. The possible use of sulfonated starch/acrylic acid IPN as a water-retarding agent in the cement industry was investigated. ζ-potential measurements were used to determine the stability of the colloidal cement—SS/AA and cement -poly-naphthalene sulfonic acid (SNF) water retarding mixtures. Sulfonated starch/acrylic acid water-retarding property was influenced by hydrogel concentration and composition. Sulfonated starch/acrylic acid IPN admixture has a great effect on the cement initial setting time. Using 2% of SS/AA or SNF resulted in an increase in initial setting time by 2 and 1 h respectively, if compared with native cement initial setting time. The results showed that the synthetic commercial super-plasticizers could be replaced by an eco-friendly water-retarding sulfonated starch/acrylic acid IPN in the cement industry.

  17. Synthesis and anticoagulant activity of bioisosteric sulfonic-Acid analogues of the antithrombin-binding pentasaccharide domain of heparin.

    PubMed

    Herczeg, Mihály; Lázár, László; Bereczky, Zsuzsanna; Kövér, Katalin E; Timári, István; Kappelmayer, János; Lipták, András; Antus, Sándor; Borbás, Anikó

    2012-08-20

    Two pentasaccharide sulfonic acids that were related to the antithrombin-binding domain of heparin were prepared, in which two or three primary sulfate esters were replaced by sodium-sulfonatomethyl moieties. The sulfonic-acid groups were formed on a monosaccharide level and the obtained carbohydrate sulfonic-acid esters were found to be excellent donors and acceptors in the glycosylation reactions. Throughout the synthesis, the hydroxy groups to be methylated were masked in the form of acetates and the hydroxy groups to be sulfated were masked with benzyl groups. The disulfonic-acid analogue was prepared in a [2+3] block synthesis by using a trisaccharide disulfonic acid as an acceptor and a glucuronide disaccharide as a donor. For the synthesis of the pentasaccharide trisulfonic acid, a more-efficient approach, which involved elongation of the trisaccharide acceptor with a non-oxidized precursor of the glucuronic acid followed by post-glycosidation oxidation at the tetrasaccharide level and a subsequent [1+4] coupling reaction, was elaborated. In vitro evaluation of the anticoagulant activity of these new sulfonic-acid derivatives revealed that the disulfonate analogue inhibited the blood-coagulation-proteinase factor Xa with outstanding efficacy; however, the introduction of the third sulfonic-acid moiety resulted in a notable decrease in the anti-Xa activity. The difference in the biological activity of the disulfonic- and trisulfonic-acid counterparts could be explained by the different conformation of their L-iduronic-acid residues.

  18. Three 2D Ag(I)-framework isomers with helical structures controlled by the chirality of camphor-10-sulfonic acid.

    PubMed

    Guo, Peng

    2011-02-28

    Three 2D Ag(I)-framework isomers were constructed from enantiopure camphor-10-sulfonic acids or racemic camphor-10-sulfonic acids, together with achiral 4-aminobenzoic acids. In complex 1, (+)-camphor-10-sulfonic acids bridge the single left-handed helices that are made up of Ag ions and 4-aminobenzoic acids, generating a homochiral 2D layer. In such a structure, the interweaving of triple left-handed homohelices was also found. It is worth noting that the helicity of complex 2 could be controlled by the handedness of the camphor-10-sulfonic acid. In complex 2, there are right-handed helical structures, including single right-handed and triple right-handed helical structures connected by (-)-camphor-10-sulfonic acids. For a comparative study, (±)-camphor-10-sulfonic acids were utilized to synthesize complex 3, in which equal numbers of right-handed or left-handed double-helical chains are created. All the complexes were characterized by single-crystal X-ray structure determination, powder X-ray diffraction, IR, TGA and element analysis. Circular dichroism spectra of complexes 1 and 2 were been studied to confirm the fact that enantiopure bridging ligands do not racemize.

  19. In silico approach to investigating the adsorption mechanisms of short chain perfluorinated sulfonic acids and perfluorooctane sulfonic acid on hydrated hematite surface.

    PubMed

    Feng, Hongru; Lin, Yuan; Sun, Yuzhen; Cao, Huiming; Fu, Jianjie; Gao, Ke; Zhang, Aiqian

    2017-05-01

    Short chain perfluorinated sulfonic acids (PFSAs) that were introduced as alternatives for perfluorooctane sulfonic acid (PFOS) have been widely produced and used. However, few studies have investigated the environmental process of short chain PFSAs, and the related adsorption mechanisms still need to be uncovered. The water-oxide interface is one of the major environmental interfaces that plays an important role in affecting the adsorption behaviour and transport potential of the environmental pollutant. In this study, we performed molecular dynamics simulations and quantum chemistry calculations to investigate the adsorption mechanisms of five PFSAs and their adsorption on hydrated hematite surface as well. Different to the vertical configuration reported for PFOS on titanium oxide, all PFSAs share the same adsorption configuration as the long carbon chains parallel to the surface. The formation of hydrogen bonds between F and inter-surface H helps to stabilize the unique configuration. As a result, the sorption capacity increases with increasing C-F chain length. Moreover, both calculated adsorption energy and partial density of states (PDOS) analysis demonstrate a PFSAs adsorption mechanism in between physical and chemical adsorption because the hydrogen bonds formed by the overlap of F (p) orbital and H (s) orbital are weak intermolecular interactions while the physical adsorption are mainly ascribed to the electrostatic interactions. This massive calculation provides a new insight into the pollutant adsorption behaviour, and in particular, may help to evaluate the environmental influence of pollutants.

  20. Syntheses of biodiesel precursors: sulfonic acid catalysts for condensation of biomass-derived platform molecules.

    PubMed

    Balakrishnan, Madhesan; Sacia, Eric R; Bell, Alexis T

    2014-04-01

    Synthesis of transportation fuel from lignocellulosic biomass is an attractive solution to the green alternative-energy problem. The production of biodiesel, in particular, involves the process of upgrading biomass-derived small molecules to diesel precursors containing a specific carbon range (C11 -C23). Herein, a carbon-upgrading process utilizing an acid-catalyzed condensation of furanic platform molecules from biomass is described. Various types of sulfonic acid catalysts have been evaluated for this process, including biphasic and solid supported catalysts. A silica-bound alkyl sulfonic acid catalyst has been developed for promoting carbon-carbon bond formation of biomass-derived carbonyl compounds with 2-methylfuran. This hydrophobic solid acid catalyst exhibits activity and selectivity that are comparable to those of a soluble acid catalyst. The catalyst can be readily recovered and recycled, possesses appreciable hydrolytic stability in the presence of water, and retains its acidity over multiple reaction cycles. Application of this catalyst to biomass-derived platform molecules led to the synthesis of a variety of furanic compounds, which are potential biodiesel precursors.

  1. Absorption and excretion of 14C-perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluoroalkyl compounds such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are industrial chemicals that are environmentally persistent. Both PFOS and PFOA are found in biosolids, and the application of these contaminated biosolids to pastures has raised concerns about possi...

  2. Preparation of sulfonic acid-containing rubbers from natural rubber vulcanizates

    NASA Astrophysics Data System (ADS)

    Poonsawat, Worapong; Poompradub, Sirilux; Ngamcharussrivichai, Chawalit

    2014-06-01

    In this work, a series of sulfonic acid-containing rubbers were prepared by aqueous phase oxidation of natural rubber vulcanizates in the presence of hydrogen peroxide (H2O2) and formic acid (HCOOH). The starting vulcanizates were neatly prepared via an efficient vulcanization (EV) system by varying mass ratio of N-cyclohexyl-2-benzothiazole sulfonamide (CBS), as an accelerator, to sulfur. The oxidation conditions were controlled at the molar ratio of H2O2: HCOOH = 1:1, the concentration of H2O2 = 15 wt.%, the temperature = 50 °C, and the reaction time = 3 h. The rubber materials before and after the oxidation were characterized for their physicochemical properties by using Fourier transform infrared spectroscopy, bomb calorimetry, acid-base titration and swelling measurements. The results indicated the presence of sulfonic acid group in the oxidized rubbers, generated by the oxidative cleaves of sulfide crosslinks in the rubber vulcanizates. The oxidation decreased the sulfur content of the rubber in which the level of sulfur loss was determined by the CBS/sulfur ratio. Moreover, the acidity of the oxidized products was correlated with the amount of sulfur remaining.

  3. Copoly(arylene ether)s containing pendant sulfonic acid groups as proton exchange membranes

    SciTech Connect

    Dae Sik, Kim; Yu Seung, Kim; Gilles, Robertson; Guiver, Michael D

    2009-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The PAE and P AEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sPAE and sPAEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (OS) of 1.0 had high ion exchange capacities (IEC{sub v})(wet) (volume-based, wet state) of 1.77 and 2.55 meq./cm3, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5 -51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the upper left-hand corner in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based), i.e., high proton conductivity and low water uptake. Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  4. Esterification Reaction of Glycerol and Palm Oil Oleic Acid Using Methyl Ester Sulfonate Acid Catalyst as Drilling Fluid Formulation

    NASA Astrophysics Data System (ADS)

    Sari, V. I.; Hambali, E.; Suryani, A.; Permadi, P.

    2017-02-01

    Esterification reaction between glycerol with palm oil oleic acid to produce glycerol ester and one of the utilization of glycerol esters is as ingredients of drilling fluids formula for oil drilling needs. The purpose of this research is to get the best conditions of the esterification process. The esterification reaction does with the reactants is glycerol with purity of 97.6%, palm oil oleic acid with the molar ratio is 1:1, Methyl Ester Sulfonate Acid (MESA) catalyst 0.5%, and stirring speed 400 rpm. The temperature range of 180°C to 240°C and the processing time between 120 to 180 minutes. The results showed that the best conditions of the esterification reaction at the temperature 240°C and time process are 180 minute. The increasing temperature resulted that the acid number decreases and causing the conversion increased. The maximum conversion is 99.24%, density 0.93 g/cm3, flash point 241°C, pour point -3°C, the boiling point of 244 °C, the acid value of 1.90 mg KOH/g sample, kinematic viscosity 31.51 cSt (40°C), surface tension 37.0526 dyne/cm and GCMS identification, glycerol ester at 22,256 retention time (minutes) and wide area 73.75 (%). From the research results obtained glycerol ester with characteristics suitable for drilling fluid formulations.

  5. Theoretical stusy of the reaction between 2,2',4' - trihydroxyazobenzene-5-sulfonic acid and zirconium

    USGS Publications Warehouse

    Fletcher, Mary H.

    1960-01-01

    Zirconium reacts with 2,2',4'-trihydroxyazobenzene-5-sulfonic acid in acid solutions to Form two complexes in which the ratios of dye to zirconium are 1 to 1 and 2 to 1. Both complexes are true chelates, with zirconium acting as a bridge between the two orthohydroxy dye groups. Apparent equilibrium constants for the reactions to form each of the complexes are determined. The reactions are used as a basis for the determination of the active component in the dye and a graphical method for the determination of reagent purity is described. Four absorption spectra covering the wave length region from 350 to 750 mu are given, which completely define the color system associated with the reactions in solutions where the hydrochloric acid concentration ranges from 0.0064N to about 7N.

  6. An Introduction to Multivariate Curve Resolution-Alternating Least Squares: Spectrophotometric Study of the Acid-Base Equilibria of 8-Hydroxyquinoline-5-Sulfonic Acid

    ERIC Educational Resources Information Center

    Rodriguez-Rodriguez, Cristina; Amigo, Jose Manuel; Coello, Jordi; Maspoch, Santiago

    2007-01-01

    A spectrophotometric study of the acid-base equilibria of 8-hydroxyquinoline-5-sulfonic acid to describe the multivariate curve resolution-alternating least squares algorithm (MCR-ALS) is described. The algorithm provides a lot of information and hence is of great importance for the chemometrics research.

  7. Asymmetric synthesis of allylic sulfonic acids: enantio- and regioselective iridium-catalyzed allylations of Na2SO3.

    PubMed

    Liu, Wei; Zhao, Xiao-ming; Zhang, Hong-bo; Zhang, Liang; Zhao, Ming-zhu

    2014-12-15

    An enantioselective allylation reaction of allylic carbonates with sodium sulfite (Na2 SO3 ) catalyzed by Ir complex was accomplished, providing allylic sulfonic acids in good to excellent yields with a high level of enantio- and regioselectivities. (R)-2-Phenyl-2-sulfoacetic acid, a key intermediate for the synthesis of Cefsulodin and Sulbenicillin, was synthesized as well.

  8. Polyaniline nanotubes and their dendrites doped with different naphthalene sulfonic acids

    SciTech Connect

    Zhang Zhiming; Wei Zhixiang; Zhang Lijuan; Wan Meixiang . E-mail: wanmx@iccas.ac.cn

    2005-03-01

    Polyaniline (PANI) nanotubes (130-250 nm in average diameter) doped with {alpha}-naphthalene sulfonic acid ({alpha}-NSA), {beta}-naphthalene sulfonic acid ({beta}-NSA) and 1,5-naphthalene disulfonic acid were synthesized via a self-assembly process. It was found that the formation yield, morphology (hollow or solid), size, crystalline and electrical properties of the nanostructures are affected by the position and number of -SO{sub 3}H groups attached to the naphthalene ring of NSA as well as the synthesis conditions. Moreover, these nanotubes aggregate to form a dendritic morphology when the polymerization is performed at a static state. The micelles composed of dopant or dopant/anilinium cations might act in a template-like fashion in forming self-assembled PANI nanotubes, which was further confirmed by X-ray diffraction measurements, while the aggregated morphology of the nanotubes might result from polymer chain interactions including {pi}-{pi} interactions, hydrogen and ionic bonds.

  9. Virucidal effects of bleach activators, sodium alkyl acyloxybenzene sulfonate and acyloxybenzoic acid, against Feline calicivirus.

    PubMed

    Tobe, Seiichi; Hoshi, Marika; Iizuka, Kinue; Tadenuma, Hirohiko; Takaoka, Hiromitsu; Komoriya, Tomoe; Kohno, Hideki

    2012-01-01

    Noroviruses (NVs) are major causative pathogens of gastroenteritis. The disinfection of contaminated clothing during common household washing is desirable. The virucidal effects of 2 bleach activators, sodium alkyl acyloxybenzene sulfonate (OBS) and alkyl acyloxybenzoic acid (OBC), were studied using Feline calicivirus (FCV) as a surrogate for NVs. FCV was added to solutions containing either OBS or OBC and sodium percarbonate at various temperatures and for varying lengths of time. OBS and OBC, which generate long carbon chain peroxy acids, enhanced the virucidal effect of sodium percarbonate (PC). In particular, sodium lauroyloxybenzene sulfonate (OBS-12) and decanoyloxybenzoic acid (OBC-10) showed superior virucidal effects. Although the virucidal effect of 38-200 mg/L OBS-12 was maintained with 2-5% (v/v) horse serum, there was less of an effect with the same concentration of available chlorine. OBS and OBC have been used as ingredients in some laundry products to increase bleaching activity. It is expected that the use of OBS and OBC is also effective for the inactivation of NVs under common household washing conditions.

  10. Ring-opening polymerization of ε-caprolactone catalyzed by sulfonic acids: computational evidence for bifunctional activation.

    PubMed

    Susperregui, Nicolas; Delcroix, Damien; Martin-Vaca, Blanca; Bourissou, Didier; Maron, Laurent

    2010-10-01

    The mechanism of ring-opening of ε-caprolactone by methanol catalyzed by trifluoromethane and methane sulfonic acids has been studied computationally at the DFT level of theory. For both elementary steps, the sulfonic acid was predicted to behave as a bifunctional catalyst. The nucleophilic addition proceeds via activation of both the monomer and the alcohol. The ring-opening involves the cleavage of the endo C-O bond of the tetrahedral intermediate with concomitant proton transfer. In both cases, the sulfonic acid acts as a proton shuttle via its acidic hydrogen atom and basic oxygen atoms. The computed activation barriers are consistent with the relatively fast polymerizations observed experimentally at room temperature with both catalysts.

  11. Effect of perfluorooctane sulfonate on the conformation of wheat germ acid phosphatase.

    PubMed

    Xu, Dongmei; Jin, Jianchang; Shen, Tong; Wang, Yanhua

    2013-11-01

    Fluorescence spectroscopy was used to study the quenching mechanism, the type of force and the binding sites of perfluorooctane sulfonate (PFOS) on wheat germ acid phosphatase (ACPase). The results showed that the quenching effect of PFOS on ACPase was mainly due to a static quenching mechanism that occurred via the formation of hydrogen bonds and van der Waals forces. The results from synchronous fluorescence spectroscopy demonstrated that PFOS interacts with ACPase close to the tryptophan residues. In addition, synchronous fluorescence spectroscopy also showed that PFOS increases the hydrophobicity of the microenvironment of the tyrosine residues, hence decreasing the local polarity.

  12. Photophysical and photosensitizing characters of 2-phenylbenzimidazole-5-sulfonic acid. A theoretical study.

    PubMed

    Shen, Liang

    2015-01-01

    The sunscreen agent 2-phenylbenzimidazole-5-sulfonic acid (PBSA) has been reported to exhibit photosensitizing activity. In the present study, the photophysical and photosensitizing properties of PBSA were investigated by means of quantum chemical calculations with the aim to gain deeper insights into the underlying photosensitizing mechanisms. The results indicate that singlet oxygen may be generated spontaneously through direct energy transfer from triplet excited state PBSA to (3)O2, and superoxide anion radical is formed through electron transfer between the anion of PBSA and (3)O2. This offers some deeper insights into the photosensitizing mechanisms of PBSA.

  13. Novel proton exchange membranes based on cardo poly(arylene ether sulfone/nitrile)s with perfluoroalkyl sulfonic acid moieties for passive direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Zheng, Jifu; He, Qingyi; Gao, Nian; Yuan, Ting; Zhang, Suobo; Yang, Hui

    2014-09-01

    A new series of cardo poly(arylene ether sulfone/nitrile)s FSPES-x with perfluoroalkyl sulfonic acid groups have been successfully prepared by the perfluorosulfonic acid lactone ring-opening reaction without using any metal or base catalysts. These materials have been characterized by IR, NMR and TGA. The results indicate that this simple and metal-free method of preparation is highly efficient for controlling both the degree of perfluorosulfonation and the position of the sulfonate group and no side reactions such as crosslinking is observed. The FSPES-x membranes (IEC = 1.17-1.64 m equiv g-1) show the desired characteristics such as good film-forming ability, excellent thermal and mechanical properties, low methanol permeability, high conductivity (up to 0.083 S cm-1 at room temperature), as well as appropriate cell performance compared to Nafion®117. With these properties, such fluorinated sulfonic acid side-chain-type polymers are promising PEM materials for application in fuel cells.

  14. Mapping protein cysteine sulfonic acid modifications with specific enrichment and mass spectrometry: an integrated approach to explore the cysteine oxidation.

    PubMed

    Chang, Yuan-Chang; Huang, Chien-Ning; Lin, Chia-Hung; Chang, Huan-Cheng; Wu, Chih-Che

    2010-08-01

    Oxidation of thiol proteins, which results in conversion of cysteine residues to cysteine sulfenic, sulfinic or sulfonic acids, is an important posttranslational control of protein function in cells. To facilitate the analysis of this process with MALDI-MS, we have developed a method for selective enrichment and identification of peptides containing cysteine sulfonic acid (sulfopeptides) in tryptic digests of proteins based on ionic affinity capture using polyarginine-coated nanodiamonds as high-affinity probes. The method was applied to selectively concentrate sulfopeptides from either a highly dilute solution or a complex peptide mixture in which the abundance of the sulfonated analyte is as low as 0.02%. The polyarginine-coated probes exhibit a higher affinity for peptides containing multiple sulfonic acids than peptides containing single sulfonic acid. The limit of the detection is in the femtomole range, with the MALDI-TOF mass spectrometer operating in the negative ion mode. The results show that the new approach has good specificity even in the presence of phosphopeptides. An application of this method for selective enrichment and structural identification of sulfopeptides is demonstrated with the tryptic digests of performic-acid-oxidized BSA.

  15. Nanocasting Design and Spatially Selective Sulfonation of Polystyrene-Based Polymer Networks as Solid Acid Catalysts.

    PubMed

    Richter, Felix H; Sahraoui, Laila; Schüth, Ferdi

    2016-09-12

    Nanocasting is a general and widely applied method in the generation of porous materials during which a sacrificial solid template is used as a mold on the nanoscale. Ideally, the resulting structure is the inverse of the template. However, replication is not always as direct as anticipated, so the influences of the degree of pore filling and of potential restructuring processes after removal of the template need to be considered. These apparent limitations give rise to opportunities in the synthesis of poly(styrene-co-divinylbenzene) (PSD) polymer networks of widely varying porosities (BET surface area=63-562 m(2)  g(-1) ; Vtot =0.18-1.05 cm(3)  g(-1) ) by applying a single synthesis methodology. In addition, spatially selective sulfonation on the nanoscale seems possible. Together, nanocasting and sulfonation enable rational catalyst design. The highly porous nanocast and predominantly surface-sulfonated PSD networks approach the activity of the corresponding molecular catalyst, para-toluenesulfonic acid, and exceed those of commercial ion-exchange polymers in the depolymerization of macromolecular inulin.

  16. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems.

  17. Electrochemical treatment of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in groundwater impacted by aqueous film forming foams (AFFFs).

    PubMed

    Schaefer, Charles E; Andaya, Christina; Urtiaga, Ana; McKenzie, Erica R; Higgins, Christopher P

    2015-09-15

    Laboratory experiments were performed to evaluate the use of electrochemical treatment for the decomposition of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), as well as other perfluoroalkyl acids (PFAAs), in aqueous film forming foam (AFFF)-impacted groundwater collected from a former firefighter training area and PFAA-spiked synthetic groundwater. Using a commercially-produced Ti/RuO2 anode in a divided electrochemical cell, PFOA and PFOS decomposition was evaluated as a function of current density (0-20 mA/cm(2)). Decomposition of both PFOA and PFOS increased with increasing current density, although the decomposition of PFOS did not increase as the current density was increased above 2.5 mA/cm(2). At a current density of 10 mA/cm(2), the first-order rate constants, normalized for current density and treatment volume, for electrochemical treatment of both PFOA and PFOS were 46 × 10(-5) and 70 × 10(-5) [(min(-1)) (mA/cm(2))(-1) (L)], respectively. Defluorination was confirmed for both PFOA and PFOS, with 58% and 98% recovery as fluoride, respectively (based upon the mass of PFOA and PFOS degraded). Treatment of other PFAAs present in the groundwater also was observed, with shorter chain PFAAs generally being more recalcitrant. Results highlight the potential for electrochemical treatment of PFAAs, particularly PFOA and PFOS, in AFFF-impacted groundwater.

  18. Removal of free fatty acid in Palm Fatty Acid Distillate using sulfonated carbon catalyst derived from biomass wastefor biodiesel production

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Rochmadi; Wijaya, Karna; Budiman, Arief

    2016-01-01

    In this research, the esterification of PFAD using the sulfonatedcoconut shell biochar catalyst was studied. Carbon solid catalysts were prepared by a sulfonation of carbonized coconut shells. The performances of the catalysts were evaluated in terms of the reaction temperatures, the molar ratios of methanol to PFAD, the catalyst loading and the reaction times. The reusability of the solid acid carbon catalysts was also studied in this work. The results indicated that the FFA conversion was significantly increased with increasing catalyst loading and reaction times. It can be concluded that the optimal conditions were an PFAD to methanol molar ratio of 1:12, the amount of catalyst of 10%w, and reaction temperature of 60oC.At this optimum condition, the conversion to biodieselreached 88%.

  19. The effect of trinitrobenzene sulfonic acid on gut-derived smooth muscle cell arachidonic acid metabolism: role of endogenous prostanoids.

    PubMed

    Longo, W E; Smith, G S; Deshpande, Y; Reickenberg, C; Kaminski, D L

    1997-01-01

    The contribution of smooth muscle cells as a potential source of eicosanoid production during inflammatory states remains to be elucidated. We investigated the effect of trinitrobenzene sulfonic acid (TNB), a known pro-inflammatory agent, on jejunal smooth muscle cell eicosanoid production. Human gut-derived smooth muscle cells (HISM) were incubated with TNB for 1 hour. Additionally, some cells were preincubated with either dimethylthiourea, or indomethacin for 1 hour before exposure to identical concentrations of TNB. Incubation with TNB led to significant increases in PGE(2) and 6-keto PGF-1(alpha) release, but not leukotriene B(4) release; responses which were both inhibited by dimethylthiourea and indomethacin treatment. Our results suggest that gutderived smooth muscle cells may represent an important source of proinflammatory prostanoids but not leukotrienes during inflammatory states of the intestine. The inhibition of prostanoid activity by thiourea may be mediated by suppression of cyclooxygenase activity in this cell line.

  20. Influence of water-soluble flavonoids, quercetin-5'-sulfonic acid sodium salt and morin-5'-sulfonic acid sodium salt, on antioxidant parameters in the subacute cadmium intoxication mouse model.

    PubMed

    Chlebda, Ewa; Magdalan, Jan; Merwid-Lad, Anna; Trocha, Małgorzata; Kopacz, Maria; Kuźniar, Anna; Nowak, Dorota; Szelag, Adam

    2010-03-01

    Water-soluble quercetin-5'-sulfonic acid sodium salt (NaQSA) and morin-5'-sulfonic acid sodium salt (NaMSA) could exert an antagonistic effect on cadmium intoxication. The aim of the study was to examine the influence of these substances on superoxide dismutase (SOD) and glutathione (GSH) levels in the mouse liver in the subacute cadmium intoxication model. NaQSA and NaMSA significantly counteracted cadmium-induced decreases in SOD and GSH levels. No significant differences in SOD and GSH levels between groups exposed to cadmium receiving NaQSA or/and NaMSA were observed.

  1. Cross-linked polystyrene sulfonic acid and polyethylene glycol as a low-fouling material.

    PubMed

    Alghunaim, Abdullah; Zhang Newby, Bi-min

    2016-04-01

    A negatively charged hydrophilic low fouling film was prepared by thermally cross-linking a blend consisting of polystyrene sulfonic acid (PSS) and polyethylene glycol (PEG). The film was found to be stable by dip-washing. The fouling resistance of this material toward bacterial (Escherichia coli) and colloidal (polystyrene particles) attachment, non-specific protein (fibronectin) adsorption and cell (3T3 NIH) adhesion was evaluated and was compared with glass slides modified with polyethylene glycol (PEG) brushes, oxidized 3-mercaptopropyltrimethoxysilane (sulfonic acid, SA), and n-octadecyltrichlorosilane (OTS). The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory and thermodynamic models based on surface energy were used to explain the interaction behaviors of E. coli/polystyrene particles-substrate and protein-substrate interactions, respectively. The cross-linked PSS-PEG film was found to be slightly better than SA and PEG toward resisting non-specific protein adsorption, and showed comparable low attachment results as those of PEG toward particle, bacterial and NIH-3T3 cells adhesion. The low-fouling performance of PSS-PEG, a cross-linked film by a simple thermal curing process, could allow this material to be used for applications in aqueous environments, where most low fouling hydrophilic polymers, such as PSS or PEG, could not be easily retained.

  2. Modification of the cellulosic component of hemp fibers using sulfonic acid derivatives: Surface and thermal characterization.

    PubMed

    George, Michael; Mussone, Paolo G; Bressler, David C

    2015-12-10

    The aim of this study was to characterize the surface, morphological, and thermal properties of hemp fibers treated with two commercially available, inexpensive, and water soluble sulfonic acid derivatives. Specifically, the cellulosic component of the fibers were targeted, because cellulose is not easily removed during chemical treatment. These acids have the potential to selectively transform the surfaces of natural fibers for composite applications. The proposed method proceeds in the absence of conventional organic solvents and high reaction temperatures. Surface chemical composition and signature were measured using gravimetric analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS data from the treated hemp fibers were characterized by measuring the reduction in O/C ratio and an increase in abundance of the C-C-O signature. FTIR confirmed the reaction with the emergence of peaks characteristic of disubstituted benzene and amino groups. Grafting of the sulfonic derivatives resulted in lower surface polarity. Thermogravimetric analysis revealed that treated fibers were characterized by lower percent degradation between 200 and 300 °C, and a higher initial degradation temperature.

  3. Synthesis, cytotoxic evaluation and in silico pharmacokinetic prediction of some benzo[a]phenazine-5-sulfonic acid derivatives.

    PubMed

    Hari Narayana Moorthy, N S; Karthikeyan, C; Trivedi, Piyush

    2009-11-01

    Cancer is one of the life threatening diseases and the development of novel anticancer molecules is limited by many reasons. In the present investigation, some novel benzo[a]phenazine-5-sulfonic acid derivatives as DNA intercalator was designed with optimized pharmacokinetic features for cancer treatment. The compounds with desired pharmacokinetic profile were synthesized and structurally characterized. Cytotoxic activity study against HL-60 tumor cell lines shows that 10-dimethyl carboxamido derivative of benzo[a]phenazine-5-sulfonic acid is found to be the most active in the series with cytotoxic activity (IC(50) = 19 microM) comparable to cisplatin (IC(50) = 7 microM). The study concluded that the novel benzo[a]phenazine-5-sulfonic acid derivatives were found to have enhanced DNA binding affinity and exhibited significant activity in vitro against HL-60 cell lines. This work will also guide for further development of effective DNA intercalators for cancer treatment.

  4. Synthesis of a Sulfonated Two-Dimensional Covalent Organic Framework as an Efficient Solid Acid Catalyst for Biobased Chemical Conversion.

    PubMed

    Peng, Yongwu; Hu, Zhigang; Gao, Yongjun; Yuan, Daqiang; Kang, Zixi; Qian, Yuhong; Yan, Ning; Zhao, Dan

    2015-10-12

    Because of limited framework stability tolerance, de novo synthesis of sulfonated covalent organic frameworks (COFs) remains challenging and unexplored. Herein, a sulfonated two-dimensional crystalline COF, termed TFP-DABA, was synthesized directly from 1,3,5-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid through a previously reported Schiff base condensation reaction, followed by irreversible enol-to-keto tautomerization, which strengthened its structural stability. TFP-DABA is a highly efficient solid acid catalyst for fructose conversion with remarkable yields (97 % for 5-hydroxymethylfurfural and 65 % for 2,5-diformylfuran), good chemoselectivity, and good recyclability. The present study sheds light on the de novo synthesis of sulfonated COFs as novel solid acid catalysts for biobased chemical conversion.

  5. Sulfonic Acid- and Lithium Sulfonate-Grafted Poly(Vinylidene Fluoride) Electrospun Mats As Ionic Liquid Host for Electrochromic Device and Lithium-Ion Battery.

    PubMed

    Zhou, Rui; Liu, Wanshuang; Leong, Yew Wei; Xu, Jianwei; Lu, Xuehong

    2015-08-05

    Electrospun polymer nanofibrous mats loaded with ionic liquids (ILs) are promising nonvolatile electrolytes with high ionic conductivity. The large cations of ILs are, however, difficult to diffuse into solid electrodes, making them unappealing for application in some electrochemical devices. To address this issue, a new strategy is used to introduce proton conduction into an IL-based electrolyte. Poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) copolymer is functionalized with sulfonic acid through covalent attachment of taurine. The sulfonic acid-grafted P(VDF-HFP) electrospun mats consist of interconnected nanofibers, leading to remarkable improvement in dimensional stability of the mats. IL-based polymer electrolytes are prepared by immersing the modified mats in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(+)BF4(-)). It is found that the SO3(-) groups can have Lewis acid-base interactions with the cations (BMIM(+)) of IL to promote the dissociation of ILs, and provide additional proton conduction, resulting in significantly improved ionic conductivity. Using this novel electrolyte, polyaniline-based electrochromic devices show higher transmittance contrast and faster switching behavior. Furthermore, the sulfonic acid-grafted P(VDF-HFP) electrospun mats can also be lithiated, giving additional lithium ion conduction for the IL-based electrolyte, with which Li/LiCoO2 batteries display enhanced C-rate performance.

  6. Synthesis and characterization of sulfonated single-walled carbon nanotubes and their performance as solid acid catalyst

    SciTech Connect

    Yu Hao Jin Yuguang; Li Zhili; Peng Feng Wang Hongjuan

    2008-03-15

    Single-walled carbon nanotubes (SWCNTs) were treated with sulfuric acid at 300 deg. C to synthesize sulfonated SWCNTs (s-SWCNTs), which were characterized by electron microscopy, infrared, Raman and X-ray photoelectron spectroscopy, and thermo analysis. Compared with activated carbon, more sulfonic acid groups can be introduced onto the surfaces of SWCNTs. The high degree ({approx}20 wt%) of surface sulfonation led to hydrophilic sidewalls that allows the SWCNTs to be uniformly dispersed in water and organic solvents. The high surface acidity of s-SWCNTs was demonstrated by NH{sub 3} temperature-programmed desorption technique and tested by an acetic acid esterification reaction catalyzed by s-SWCNTs. The results show that the water-dispersive s-SWCNTs are an excellent solid acid catalyst and demonstrate the potential of SWCNTs in catalysis applications. - Graphical abstract: Sulfonated SWCNTs with 20 wt% -SO{sub 2}OH groups were prepared by a high-temperature H{sub 2}SO{sub 4} process, which transformed the hydrophobic surface of pristine SWCNTs to a hydrophilic surface and provided an excellent performance as solid acid catalyst.

  7. Alkyl sulfonic acide hydrazides: Synthesis, characterization, computational studies and anticancer, antibacterial, anticarbonic anhydrase II (hCA II) activities

    NASA Astrophysics Data System (ADS)

    O. Ozdemir, Ummuhan; İlbiz, Firdevs; Balaban Gunduzalp, Ayla; Ozbek, Neslihan; Karagoz Genç, Zuhal; Hamurcu, Fatma; Tekin, Suat

    2015-11-01

    Methane sulfonic acide hydrazide, CH3SO2NHNH2 (1), ethane sulfonic acide hydrazide, CH3CH2SO2NHNH2 (2), propane sulfonic acide hydrazide, CH3CH2CH2SO2NHNH2 (3) and butane sulfonic acide hydrazide, CH3CH2CH2CH2SO2NHNH2 (4) have been synthesized as homologous series and characterized by using elemental analysis, spectrophotometric methods (1H-13C NMR, FT-IR, LC-MS). In order to gain insight into the structure of the compounds, we have performed computational studies by using 6-311G(d, p) functional in which B3LYP functional were implemented. The geometry of the sulfonic acide hydrazides were optimized at the DFT method with Gaussian 09 program package. A conformational analysis of compounds were performed by using NMR theoretical calculations with DFT/B3LYP/6-311++G(2d, 2p) level of theory by applying the (GIAO) approach. The anticancer activities of these compounds on MCF-7 human breast cancer cell line investigated by comparing IC50 values. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Gram negative bacteria; Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442, Klebsiella pneumonia ATCC 70063 by using the disc diffusion method. The inhibition activities of these compounds on carbonic anhydrase II enzyme (hCA II) have been investigated by comparing IC50 and Ki values. The biological activity screening shows that butane sulfonic acide hydrazide (4) has more activity than the others against tested breast cancer cell lines MCF-7, Gram negative/Gram positive bacteria and carbonic anhydrase II (hCA II) isoenzyme.

  8. Toxicokinetics of seven perfluoroalkyl sulfonic and carboxylic acids in pigs fed a contaminated diet.

    PubMed

    Numata, Jorge; Kowalczyk, Janine; Adolphs, Julian; Ehlers, Susan; Schafft, Helmut; Fuerst, Peter; Müller-Graf, Christine; Lahrssen-Wiederholt, Monika; Greiner, Matthias

    2014-07-16

    The transfer of a mixture of perfluoroalkyl acids (PFAAs) from contaminated feed into the edible tissues of 24 fattening pigs was investigated. Four perfluoroalkyl sulfonic (PFSAs) and three perfluoroalkyl carboxylic acids (PFCAs) were quantifiable in feed, plasma, edible tissues, and urine. As percentages of unexcreted PFAA, the substances accumulated in plasma (up to 51%), fat, and muscle tissues (collectively, meat 40-49%), liver (under 7%), and kidney (under 2%) for most substances. An exception was perfluorooctanesulfonic acid (PFOS), with lower affinity for plasma (23%) and higher for liver (35%). A toxicokinetic model is developed to quantify the absorption, distribution, and excretion of PFAAs and to calculate elimination half-lives. Perfluorohexanoic acid (PFHxA), a PFCA, had the shortest half-life at 4.1 days. PFSAs are eliminated more slowly (e.g., half-life of 634 days for PFOS). PFAAs in pigs exhibit longer elimination half-lives than in most organisms reported in the literature, but still shorter than in humans.

  9. Influence of volatile fatty acid concentration stability on anaerobic degradation of linear alkylbenzene sulfonate.

    PubMed

    Okada, Dagoberto Y; Delforno, Tiago P; Esteves, Andressa S; Polizel, Juliana; Hirasawa, Julia S; Duarte, Iolanda C S; Varesche, Maria B A

    2013-10-15

    Linear alkylbenzene sulfonate (LAS) is an anionic surfactant used in cleaning products, which is usually found in wastewaters. Despite the greater LAS removal rate related to a lower concentrations of volatile fatty acids (VFA), the influence of different ranges of VFA on LAS degradation is not known. LAS degradation was evaluated in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors at different ranges of VFA concentrations. The reactors were fed with a synthetic wastewater containing LAS (14 mg/L). A greater LAS removal rate (40-80%) was related to the lower and narrower range of acetic acid concentration (1-22 mg/L) in the EGSB reactor. In the UASB reactor, the acetic acid concentrations presented a wider range (2-45 mg/L), and some low LAS removal rates (around 20-25%) were observed even at low acetic acid concentrations (<10 mg/L). The high recirculation rate in the EGSB reactor improved substrate-biomass contact, which resulted in a narrower range of VFA and greater LAS removal rate.

  10. Fluorinated alternatives to long-chain perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs) and their potential precursors.

    PubMed

    Wang, Zhanyun; Cousins, Ian T; Scheringer, Martin; Hungerbühler, Konrad

    2013-10-01

    Since 2000 there has been an on-going industrial transition to replace long-chain perfluoroalkyl carboxylic acids(PFCAs), perfluoroalkane sulfonic acids (PFSAs) and their precursors. To date, information on these replacements including their chemical identities, however, has not been published or made easily accessible to the public, hampering risk assessment and management of these chemicals. Here we review information on fluorinated alternatives in the public domain. We identify over 20 fluorinated substances that are applied in [i] fluoropolymer manufacture, [ii] surface treatment of textile, leather and carpets, [iii] surface treatment of food contact materials,[iv] metal plating, [v] fire-fighting foams, and [vi] other commercial and consumer products.We summarize current knowledge on their environmental releases, persistence, and exposure of biota and humans. Based on the limited information available, it is unclear whether fluorinated alternatives are safe for humans and the environment.We identify three major data gaps that must be filled to perform meaningful risk assessments and recommend generation of the missing data through cooperation among all stakeholders (industry, regulators, academic scientists and the public).

  11. Analysis of perfluorinated phosponic acids and perfluorooctane sulfonic acid in water, sludge and sediment by LC-MS/MS.

    PubMed

    Esparza, X; Moyano, E; de Boer, J; Galceran, M T; van Leeuwen, S P J

    2011-10-30

    Residues of perfluorinated phosphonic acids (PFPAs) and perfluorooctane sulfonic acid (PFOS) were investigated in various Dutch surface waters, sludge and sediments. For this purpose, a liquid chromatographic (LC) method was optimized by testing several columns with different mobile phases. Atmospheric pressure chemical ionization (APCI) was chosen for the LC tandem mass spectrometry (MS/MS) analysis. An ion-pair reagent was added to the injection solvent to improve peak shape. Different solvents were studied for the extraction from solid samples. For clean-up and pre-concentration, weak anion-exchange solid-phase extraction cartridges were used. Water samples were extracted using the same cartridges. The method was used for screening PFPAs in the Dutch aquatic environment. PFPAs were not observed in sediment or sludge samples. PFOPA was found at 1 ng L(-1) in one surface water sample. PFOS was found at levels between 0.07 ng g(-1) and 48 ng g(-1) (dry weight) in sediments and sewage sludge samples. PFOS concentrations in surface water ranged from 3.3 ng L(-1) to 25.4 ng L(-1).

  12. Biochemical Studies of Bacterial Sporulation and Germination XII. A Sulfonic Acid as a Major Sulfur Compound of Bacillus subtilis Spores

    PubMed Central

    Bonsen, Pieter P. M.; Spudich, James A.; Nelson, David L.; Kornberg, Arthur

    1969-01-01

    A sulfonic acid found to be a major constituent of spores of Bacillus subtilis was provisionally identified as 3-l-sulfolactic acid. This compound was completely absent from vegetative cells during growth, but large amounts accumulated in sporulating cells just before the development of refractile spores. Essentially all of the accumulated sulfolactic acid was eventually incorporated into the nature spore, where it may represent more than 5% of the dry weight of the spore. Germination resulted in the rapid and complete release into the medium of unaltered sulfolactic acid. This compound was not found in spores of Bacillus megaterium, B. cereus, or B. thuringiensis. Images PMID:4977690

  13. Sulfonated reduced graphene oxide as a highly efficient catalyst for direct amidation of carboxylic acids with amines using ultrasonic irradiation.

    PubMed

    Mirza-Aghayan, Maryam; Tavana, Mahdieh Molaee; Boukherroub, Rabah

    2016-03-01

    Sulfonated reduced graphene oxide nanosheets (rGO-SO3H) were prepared by grafting sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide (rGO) under sonochemical conditions. rGO-SO3H catalyst was characterized by Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). rGO-SO3H catalyst was successfully applied as a reusable solid acid catalyst for the direct amidation of carboxylic acids with amines into the corresponding amides under ultrasonic irradiation. The direct sonochemical amidation of carboxylic acid takes place under mild conditions affording in good to high yields (56-95%) the corresponding amides in short reaction times.

  14. Detection of a cyclic perfluorinated acid, perfluoroethylcyclohexane sulfonate, in the Great Lakes of North America.

    PubMed

    De Silva, Amila O; Spencer, Christine; Scott, Brian F; Backus, Sean; Muir, Derek C G

    2011-10-01

    Perfluoroethylcyclohexanesulfonate (PFECHS) is a cyclic perfluorinated acid (PFA) mainly used as an erosion inhibitor in aircraft hydraulic fluids. It is expected to be as recalcitrant to environmental degradation as aliphatic PFAs including perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). For the first time, PFECHS is reported in top predator fish (sulfonate (PFMeCHS), was also detected in the dissolved phase but not above detection limits in fish tissue. Bioaccumulation factors (BAFs) were estimated by taking the ratio of fish to water concentrations. The mean log BAF values corresponded to 2.8 for PFECHS, 2.1 for PFOA, and 4.5 for PFOS. It is not certain whether the fish-water BAF for PFECHS is an overestimate due to the influence of precursor biotransformation. Further studies are recommended to understand the extent of PFECHS contamination.

  15. Synthesis, characterization, antibacterial activity and quantum chemical studies of N'-Acetyl propane sulfonic acid hydrazide

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Alyar, Hamit; Ozdemir, Ummuhan Ozmen; Sahin, Omer; Kaya, Kerem; Ozbek, Neslihan; Gunduzalp, Ayla Balaban

    2015-08-01

    A new N'-Acetyl propane sulfonic acid hydrazide, C3H7sbnd SO2sbnd NHsbnd NHsbnd COCH3 (Apsh, an sulfon amide compound) has been synthesized for the first time. The structure of Apsh was investigated using elemental analysis, spectral (IR, 1H/13C NMR) measurements. In addition, molecular structure of the Apsh was determined by single crystal X-ray diffraction technique and found that the compound crystallizes in monoclinic, space group P 21/c. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The structure of Apsh is optimized using Density Functional Theory (DFT) method. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The theoretical IR frequencies are found to be in good agreement with the experimental IR frequencies. Nonlinear optical (NLO) behaviour of Apsh is also examined by the theoretically predicted values of dipole moment (μ), polarizability (α0) and first hyperpolarizability (βtot). The antibacterial activities of synthesized compound were studied against Gram positive bacteria: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 23212, Staphylococcus epidermidis ATCC 34384, Gram negative bacteria: Eschericha coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70063 by using microdilution method (as MICs) and disc diffusion method.

  16. Fluorescence quenching method for the determination of carbazochrome sodium sulfonate with aromatic amino acids.

    PubMed

    Gan, Xiao-Juan; Liu, Shao-Pu; Liu, Zhong-Fang; Hu, Xiao-Li; Tian, Jing; Xue, Jia-Xing

    2013-01-01

    In Britton-Robinson (BR) buffer medium (pH 3.3), carbazochrome sodium sulfonate (CSS) can react with some aromatic amino acids such as tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) to form a 1:1 complex by electrostatic attraction, aromatic stacking interaction and Van der Waals' force, resulting in fluorescence quenching of these amino acids. Maximum quenching wavelengths were located at 352 nm (CSS-Trp system), 303 nm (CSS-Tyr system) and 284 nm (CSS-Phe system), respectively. The fluorescence quenching value (ΔF) was proportional to the concentration of CSS in a certain range. The fluorescence quenching method for the determination of CSS showed high sensitivity, with detection limits of 31.3 ng/mL (CSS-Trp system), 44.6 ng/mL (CSS-Tyr system) and 315.0 ng/mL (CSS-Phe system), respectively. The optimum conditions of the reaction conditions and the effect of coexisting substances were investigated and results showed that the method had good selectivity. The method was successfully applied for the rapid determination of CSS in blood and urine samples. Based on the bimolecular quenching constant Kq , the effect of temperature and Stern-Volmer plots, this study showed that quenching of fluorescence of amino acids by CSS was a static quenching process.

  17. The Liebermann-Burchard reaction: sulfonation, desaturation, and rearrangment of cholesterol in acid.

    PubMed

    Xiong, Quanbo; Wilson, William K; Pang, Jihai

    2007-02-01

    In the Liebermann-Burchard (LB) colorimetric assay, treatment of cholesterol with sulfuric acid, acetic anhydride, and acetic acid elicits a blue color. We studied the reactivity of cholesterol under LB conditions and provide definitive NMR characterization for approximately 20 products, whose structure and distribution suggest the following mechanistic picture. The major reaction pathways do not involve cholestadienes, i-steroids, or cholesterol dimers, as proposed previously. Instead, cholesterol and its acetate and sulfate derivatives undergo sulfonation at a variety of positions, often with skeletal rearrangements. Elimination of an SO(3)H group as H(2)SO(3) generates a new double bond. Repetition of this desaturation process leads to polyenes and ultimately to aromatic steroids. Linearly conjugated polyene cations can appear blue but form too slowly to account for the LB color response, whose chemical origin remains unidentified. Nevertheless, the classical polyene cation model is not excluded for Salkowski conditions (sulfuric acid), which immediately generate considerable amounts of cholesta-3,5-diene. Some rearrangements of cholesterol in H(2)SO(4) resemble the diagenesis pathways of sterols and may furnish useful lipid biomarkers for characterizing geological systems.

  18. Sulfonic-hydroxyl-type heterogemini surfactants synthesized from unsaturated fatty acids.

    PubMed

    Sakai, Kenichi; Sangawa, Yuta; Takamatsu, Yuichiro; Kawai, Takeshi; Matsumoto, Mutsuyoshi; Sakai, Hideki; Abe, Masahiko

    2010-01-01

    Novel anionic heterogemini surfactants have been synthesized from two kinds of unsaturated fatty acids (oleic acid and petroselinic acid). The hydrocarbon chain is covalently bound to the terminal carbonyl group of the unsaturated fatty acids and hydrophilic headgroups (i.e., sulfonic and hydroxyl groups) are introduced to the cis double bond. The aqueous solution properties of the surfactants synthesized here have been studied on the basis of static/dynamic surface tension, conductivity, fluorescence, and dynamic light scattering (DLS) data. We have mainly focused on the following two factors that may significantly impact the aqueous solution properties of the surfactants: one is hydrocarbon chain length and the other is molecular symmetry. The first key result from our current study is that increased hydrocarbon chain length results in a closely packed monolayer film at the air/aqueous solution interface, even at low concentrations as a result of the increased hydrophobicity of the longer chain analogue. We have previously observed a similar trend when aqueous solution properties of oleic acid-based phosphate-type heterogemini surfactants were studied. The second key finding of our current research is that increased molecular symmetry results in greater surface activities (which include lower aqueous surface tension and greater molecular packing at the air/aqueous solution interface). In addition, it seems likely that the size of molecular assemblies spontaneously formed in bulk solution decreases when the molecular symmetry increases. These results suggest that the symmetric analogue provides greater hydrophobic environments, although the exact reason for this is not yet known.

  19. Sulfonic acid-functionalized α-zirconium phosphate single-layer nanosheets as a strong solid acid for heterogeneous catalysis applications.

    PubMed

    Zhou, Yingjie; Huang, Rongcai; Ding, Fuchuan; Brittain, Alex D; Liu, Jingjing; Zhang, Meng; Xiao, Min; Meng, Yuezhong; Sun, Luyi

    2014-05-28

    Solid acids have received considerable attention as alternatives to traditional corrosive and hazardous homogeneous acids because of their advantages in practical applications, including their low corrosion of equipment and high catalytic activity and recyclability. In this work, a strong solid acid was prepared by anchoring thiol group terminated chains on layered α-zirconium phosphate (ZrP) single-layer nanosheets, followed by oxidation of thiol groups to form sulfonic acid groups. The obtained solid acids were thoroughly characterized and the results proved that sulfonic acid group terminated chains were successfully grafted onto the ZrP nanosheets with a high loading density. Such a strong solid acid based on inorganic nanosheets can be well-dispersed in polar solvents, leading to high accessibility to the acid functional groups. Meanwhile, it can be easily separated from the dispersion system by centrifugation or filtration. The strong solid acid can serve as an effective heterogeneous catalyst for various reactions, including the Bayer-Villiger oxidation of cyclohexanone to ε-caprolactone in the absence of organic solvents.

  20. Identification of a new sulfonic acid metabolite of metolachlor in soil

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.; Yockel, M.E.; Zimmerman, L.R.; Williams, T.D.

    1996-01-01

    An ethanesulfonic acid metabolite of metolachlor (metolachlor ESA) was identified in soil-sample extracts by negative-ion, fast-atom bombardment mass spectrometry (FAB-MS) and FAB tandem mass spectrometry (FAB-MS/MS). Production fragments from MS/MS analysis of the deprotonated molecular ion of metolachlor ESA in the soil extract can be reconciled with the structure of the synthesized standard. The elemental compositions of the (M - H)- ions of the metolachlor ESA standard and the soil-sample extracts were confirmed by high-resolution mass spectrometry. A dissipation study revealed that metolachlor ESA is formed in soil under field conditions corresponding to a decrease in the concentration of the parent herbicide, metolachlor. The identification of the sulfonated metabolite of metolachlor suggests that the glutathione conjugation pathway is a common detoxification pathway shared by chloroacetanilide herbicides.

  1. Chemical doping of MoS2 multilayer by p-toluene sulfonic acid

    PubMed Central

    Andleeb, Shaista; Kumar Singh, Arun; Eom, Jonghwa

    2015-01-01

    We report the tailoring of the electrical properties of mechanically exfoliated multilayer (ML) molybdenum disulfide (MoS2) by chemical doping. Electrical charge transport and Raman spectroscopy measurements revealed that the p-toluene sulfonic acid (PTSA) imposes n-doping in ML MoS2. The shift of threshold voltage for ML MoS2 transistor was analyzed as a function of reaction time. The threshold voltage shifted toward more negative gate voltages with increasing reaction time, which indicates an n-type doping effect. The shift of the Raman peak positions was also analyzed as a function of reaction time. PTSA treatment improved the field-effect mobility by a factor of ~4 without degrading the electrical characteristics of MoS2 devices. PMID:27877810

  2. Identification of small molecule sulfonic acids as ecto-5'-Nucleotidase inhibitors.

    PubMed

    Raza, Rabia; Saeed, Aamer; Lecka, Joanna; Sévigny, Jean; Iqbal, Jamshed

    2012-11-01

    Ecto-5'-Nucleotidase inhibitors have great potential as anti-tumor agents. We have investigated biochemical properties of human and rat ecto-5'-Nucleotidases and characterized 19 small molecule sulfonic acid derivatives as potential inhibitors of ecto-5'-Nucleotidases. We identified 11 potent inhibitors of human and rat ecto-5'-Nucleotidases and checked their selectivity. Compound 10 (Sodium 2,4-dinitrobenzenesulfonate) with K(i) value of 0.66 μM and 19 (N-(4-sulfamoylphenylcarbamothioyl) pivalamide) with K(i) value of 0.78 μM were identified as the most potent inhibitors for human and rat ecto-5'-Nucleotidase, respectively. The present compounds have low molecular weights, water solubility and equal potency as compared to the reported inhibitors.

  3. Transfer of perfluorooctane sulfonic acid (PFOS) from contaminated feed to dairy milk.

    PubMed

    van Asselt, E D; Kowalczyk, J; van Eijkeren, J C H; Zeilmaker, M J; Ehlers, S; Fürst, P; Lahrssen-Wiederholt, M; van der Fels-Klerx, H J

    2013-11-15

    Dietary intake is the predominant route for human exposure to perfluorooctane sulfonic acid (PFOS). Single pollution events may thus affect human exposure if polluted ground and water is used to produce animal feed or food. In this study, a physiologically based pharmacokinetic (PBPK-) model is derived that describes the uptake of PFOS from contaminated feed by cows and its subsequent elimination through the cows' milk. Parameter values of the model were estimated by fitting to experimental data of a cow feeding trial. Model calculations showed that almost all PFOS ingested is excreted through the cows' milk. The elimination rate, however, was low as the estimated half-life in the cow was 56days and it may, thus, take a long time after an initial pollution event to produce PFOS-free milk. The derived model can be used to estimate the transfer of PFOS through the dairy food chain and can be used for comparison of various contamination routes.

  4. Assessment of perfluorooctanoic acid and perfluorooctane sulfonate in surface water - Tamil Nadu, India.

    PubMed

    Sunantha, Ganesan; Vasudevan, Namasivayam

    2016-08-15

    As an emerging class of environmentally persistent organic pollutants, perfluorinated compounds (PFCs), particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS); have been universally found in the environment. Wastewater and untreated effluents are likely the major causes for the accumulation of PFCs in surface water. There are very few reports on the contamination of PFCs in the developing countries, particularly in India. This study reports the quantitative analysis of PFOA and PFOS in Noyyal, Cauvery, and also lakes in and around Chennai, using Ultra-Fast liquid chromatograph. The concentration of PFOA and PFOS ranged from 4 to 93ng/L and 3 to 29ng/L, respectively. The concentration of PFOS was below detectable limit in Cauvery River. A reliable concentration of PFOA was recorded at all sites of River Cauvery (5ng/L). The present study could be useful for the assessment of future monitoring programs of PFOA and PFOS in the surface water.

  5. Sorption of REE and TPE from HNO{sub 3} solutions on strong-acid sulfonated cation exchanger KU-2

    SciTech Connect

    Chuveleva, E.A.; Kharitonov, O.V.; Firsova, L.A.

    1995-05-01

    Sorption of rare earths (REE) on the strong-acid sulfonated cation exchanger KU-2 is studied as a function of the solution acidity (0.1-2.0 M HNO{sub 3}) and REE concentration. In concentrated nitrate solutions where M(NO{sub 3}){sub 2}{sup +} and M(NO{sub 3}){sub 2}{sup +} can form and be sorbed by the cation exchanger, the capacity of the exchanger seems to increase by 20%.

  6. Analysis of metolachlor ethane sulfonic acid chirality in groundwater: A tool for dating groundwater movement in agricultural settings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical chirality of pesticides can be a useful tool for studying environmental processes. The chiral forms of metolachlor ethane sulfonic acid (MESA), an abundant metabolite of metolachlor, and metolachlor were examined over a 6 year period in groundwater and a groundwater-fed stream in a riparia...

  7. Sulfonic acid functionalized nano γ-Al2O3 catalyzed per-O-acetylated of carbohydrates.

    PubMed

    Wu, Liqiang; Yin, Zhikui

    2013-01-10

    A simple and clean synthesis of per-O-acetylation carbohydrate derivatives has been accomplished by treatment of sugars with a stoichiometric quantity of acetic anhydride under solvent-free conditions in the presence of sulfonic acid functionalized nano γ-Al(2)O(3) as an efficient and environmentally benign catalyst.

  8. Inactivation of a class A and a class C β-lactamase by 6β-(hydroxymethyl)penicillanic acid sulfone

    PubMed Central

    Papp-Wallace, Krisztina M.; Bethel, Christopher R.; Gootz, Thomas D.; Shang, Wenchi; Stroh, Justin; Lau, William; McLeod, Dale; Price, Loren; Marfat, Anthony; Distler, Anne; Drawz, Sarah M.; Chen, Hansong; Harry, Emily; Nottingham, Micheal; Carey, Paul R.; Buynak, John D.; Bonomo, Robert A.

    2012-01-01

    β-Lactamase inhibitors (clavulanic acid, sulbactam, and tazobactam) contribute significantly to the longevity of the β-lactam antibiotics used to treat serious infections. In the quest to design more potent compounds and to understand the mechanism of action of known inhibitors, 6β-(hydroxymethyl)penicillanic acid sulfone (6β-HM-sulfone) was tested against isolates expressing the class A TEM-1 β-lactamase and a clinically important variant of the AmpC cephalosporinase of Pseudomonas aeruginosa, PDC-3. The addition of the 6β-HM-sulfone inhibitor to ampicillin was highly effective. 6β-HM-sulfone inhibited TEM-1 with an IC50 of 12 ± 2 nM and PDC-3 with an IC50 of 180 ± 36 nM, and displayed lower partition ratios than commercial inhibitors, with partition ratios (kcat/kinact) equal to 174 for TEM-1 and 4 for PDC-3. Measured for 20 h, 6β-HM-sulfone demonstrated rapid, first-order inactivation kinetics with the extent of inactivation being related to the concentration of inhibitor for both TEM-1 and PDC-3. Using mass spectrometry to gain insight into the intermediates of inactivation of this inhibitor, 6β-HM-sulfone was found to form a major adduct of +247 ± 5 Da with TEM-1 and +245 ± 5 Da with PDC-3, suggesting that the covalently bound, hydrolytically stabilized acyl-enzyme has lost a molecule of water (H–O–H). Minor adducts of +88 ± 5 Da with TEM-1 and +85 ± 5 Da with PDC-3 revealed that fragmentation of the covalent adduct can result but appeared to occur slowly with both enzymes. 6β-HM-sulfone is an effective and versatile β-lactamase inhibitor of representative class A and C enzymes. PMID:22155308

  9. Discovery and Characterization of Diazenylaryl Sulfonic Acids as Inhibitors of Viral and Bacterial Neuraminidases.

    PubMed

    Hoffmann, Anja; Richter, Martina; von Grafenstein, Susanne; Walther, Elisabeth; Xu, Zhongli; Schumann, Lilia; Grienke, Ulrike; Mair, Christina E; Kramer, Christian; Rollinger, Judith M; Liedl, Klaus R; Schmidtke, Michaela; Kirchmair, Johannes

    2017-01-01

    Viral neuraminidases are an established drug target to combat influenza. Severe complications observed in influenza patients are primarily caused by secondary infections with e.g., Streptococcus pneumoniae. These bacteria engage in a lethal synergism with influenza A viruses (IAVs) and also express neuraminidases. Therefore, inhibitors with dual activity on viral and bacterial neuraminidases are expected to be advantageous for the treatment of influenza infections. Here we report on the discovery and characterization of diazenylaryl sulfonic acids as dual inhibitors of viral and Streptococcus pneumoniae neuraminidase. The initial hit came from a virtual screening campaign for inhibitors of viral neuraminidases. For the most active compound, 7-[2-[4-[2-[4-[2-(2-hydroxy-3,6-disulfo-1-naphthalenyl)diazenyl]-2-methylphenyl]diazenyl]-2-methylphenyl]diazenyl]-1,3-naphthalenedisulfonic acid (NSC65847; 1), the Ki-values measured in a fluorescence-based assay were lower than 1.5 μM for both viral and pneumococcal neuraminidases. The compound also inhibited N1 virus variants containing neuraminidase inhibitor resistance-conferring substitutions. Via enzyme kinetics and nonlinear regression modeling, 1 was suggested to impair the viral neuraminidases and pneumococcal neuraminidase with a mixed-type inhibition mode. Given its antiviral and antipneumococcal activity, 1 was identified as a starting point for the development of novel, dual-acting anti-infectives.

  10. Discovery and Characterization of Diazenylaryl Sulfonic Acids as Inhibitors of Viral and Bacterial Neuraminidases

    PubMed Central

    Hoffmann, Anja; Richter, Martina; von Grafenstein, Susanne; Walther, Elisabeth; Xu, Zhongli; Schumann, Lilia; Grienke, Ulrike; Mair, Christina E.; Kramer, Christian; Rollinger, Judith M.; Liedl, Klaus R.; Schmidtke, Michaela; Kirchmair, Johannes

    2017-01-01

    Viral neuraminidases are an established drug target to combat influenza. Severe complications observed in influenza patients are primarily caused by secondary infections with e.g., Streptococcus pneumoniae. These bacteria engage in a lethal synergism with influenza A viruses (IAVs) and also express neuraminidases. Therefore, inhibitors with dual activity on viral and bacterial neuraminidases are expected to be advantageous for the treatment of influenza infections. Here we report on the discovery and characterization of diazenylaryl sulfonic acids as dual inhibitors of viral and Streptococcus pneumoniae neuraminidase. The initial hit came from a virtual screening campaign for inhibitors of viral neuraminidases. For the most active compound, 7-[2-[4-[2-[4-[2-(2-hydroxy-3,6-disulfo-1-naphthalenyl)diazenyl]-2-methylphenyl]diazenyl]-2-methylphenyl]diazenyl]-1,3-naphthalenedisulfonic acid (NSC65847; 1), the Ki-values measured in a fluorescence-based assay were lower than 1.5 μM for both viral and pneumococcal neuraminidases. The compound also inhibited N1 virus variants containing neuraminidase inhibitor resistance-conferring substitutions. Via enzyme kinetics and nonlinear regression modeling, 1 was suggested to impair the viral neuraminidases and pneumococcal neuraminidase with a mixed-type inhibition mode. Given its antiviral and antipneumococcal activity, 1 was identified as a starting point for the development of novel, dual-acting anti-infectives. PMID:28261167

  11. Poly(p-Phenylene Sulfonic Acids). PEMs with frozen-in free volume

    SciTech Connect

    Litt, Morton

    2016-01-21

    Early work with rigid rod aromatic polyelectrolytes implied that steric hindrance in packing of the rigid rods left unoccupied volumes that could absorb and hold water molecules strongly. We called this “frozen in free volume). It is illustrated and contrasted with the packing of flexible backbone polyelectrolytes (Reference 5 of this report). This was quantified for poly(biphenylene disulfonic acid) (PBDSA) and poly(phenylene disulfonic acid) (PPDSA). We found that PPDSA held three water molecules per acid group down to 11% relative humidity (RH) and had very high conductivity even at these low RHs. (Reference 1 of report.) The frozen-in free volume was calculated to be equivalent to a λ of 3.5. The work reported below concentrated on studying these polymers and their copolymers with biphenylene disulfonic acid. As expected, the polyelectrolytes are water soluble. Several approaches towards making water stable films were studied. Grafting alkyl benzene substituents on sulfonic acid groups had worked for PBPDSA (1) so it was tried with PPDSA and a 20%/80% copolymer of BPDSA and PDSA (B20P80). T-butyl, n-octyl and n-dodecyl benzene were grafted. Good films could be made. Water absorption and conductivity were studied as a function of RH and temperature (Reference 2). When less than 20% of the sulfonic acid groups were grafted, conductivity was much higher than that of Nafion NR212 at all RHs. At low graft levels, conductivity was ten times higher. Mechanical properties and swelling were acceptable below 90% RH. However, all the films were unstable in water and slowly disintegrated. The proposed explanation was that the molecules formed nano-aggregates in solution held together by hydrophobic bonding. Their cast films disintegrated when placed in water since hydrophobic bonding between the nano-aggregates was poor. We then shifted to crosslinking as a method to produce water stable films (References 3 and 4). Biphenyl could easily be reacted with the polymer

  12. Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: Synthesis, characterization and application

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Christopher

    The major goals of this thesis were to: (1) create a site-isolated aminosilica material with higher amine loadings than previously reported isolation methods, (2) use spectroscopic, reactivity, and catalytic (olefin polymerization precatalysts) probes to determine isolation of amine groups on these organic/inorganic hybrid materials, (3) synthesize an organic/inorganic hybrid material capable of activating Group 4 olefin polymerization precatalysts, and (4) synthesize a high amine loaded organic/inorganic hybrid material capable of reversibly capturing CO2 in a simulated flue gas stream. The underlying motivation of this research involved the synthesis and design of novel amine and sulfonic acid materials. Traditional routes to synthesize aminosilicas have led to the formation of a high loading of multiple types of amine sites on the silica surface. Part of this research involved the creation of a new aminosilica material via a protection/deprotection method designed to prevent multiple sites, while maintaining a relatively high loading. As a characterization technique, fluorescence spectroscopy of pyrene-based fluorophores loaded on traditional aminosilicas and site-isolated aminosilicas was used to probe the degree of site-isolation obtained with these methods. Also, this protection/deprotection method was compared to other reported isolation techniques with heterogeneous Group 4 constrained-geometry inspired catalysts (CGCs). It was determined that the degree of separation of the amine sites could be controlled with protection/deprotection methods. Furthermore, an increase in the reactivity of the amines and the catalytic activity of CGCs built off of the amines was determined for aminosilicas synthesized by a protection/deprotection method. The second part of this work involved developing organic/inorganic hybrid materials as heterogeneous Bronsted acidic cocatalysts for activation of olefin polymerization precatalysts. This was the first reported organic

  13. Esterification of oil adsorbed on palm decanter cake into methyl ester using sulfonated rice husk ash as heterogeneous acid catalyst

    NASA Astrophysics Data System (ADS)

    Hindryawati, Noor; Erwin, Maniam, Gaanty Pragas

    2017-02-01

    Palm Decanter cake (PDC) which is categorized as the waste from palm oil mill has been found to contain residual crude palm oil. The oil adsorbed on the PDC (PDC-oil) can be extracted and potentially used as feedstock for biodiesel production. Feedstock from waste like PDC-oil is burdened with high free fatty acids (FFAs) which make the feedstock difficult to be converted into biodiesel using basic catalyst. Therefore, in this study, a solid acid, RHA-SO3H catalyst was synthesized by sulfonating rice husk ash (RHA) with concentrated sulfuric acid. The RHA-SO3H prepared was characterized with TGA, FTIR, BET, XRD, FE-SEM, and Hammett indicators (methyl red, bromophenol blue, and crystal violet). PDC was found to have about 11.3 wt. % oil recovered after 1 hour extraction using ultrasound method. The presence of sulfonate group was observed in IR spectrum, and the surface area of RHA-SO3H was reduced to 37 m2.g-1 after impregnation of sulfonate group. The RHA-SO3H catalyst showed that it can work for both esterification of free fatty acid which is present in PDC-oil, and transesterification of triglycerides into methyl ester. The results showed highest methyl ester content of 70.2 wt.% at optimal conditions, which was 6 wt.% catalyst amount, methanol to oil molar ratio of 17:1 for 5 hours at 120 °C.

  14. Synthesis and solid-state NMR characterization of cubic mesoporous silica SBA-1 functionalized with sulfonic acid groups.

    PubMed

    Tsai, Hui-Hsu Gavin; Chiu, Po-Jui; Jheng, Guang-Liang; Ting, Chun-Chiang; Pan, Yu-Chi; Kao, Hsien-Ming

    2011-07-01

    Well-ordered cubic mesoporous silicas SBA-1 functionalized with sulfonic acid groups have been synthesized through in situ oxidation of mercaptopropyl groups with H(2)O(2) via co-condensation of tetraethoxysilane (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) templated by cetyltriethylammonium bromide (CTEABr) under strong acidic conditions. Various synthesis parameters such as the amounts of H(2)O(2) and MPTMS on the structural ordering of the resultant materials were systematically investigated. The materials thus obtained were characterized by a variety of techniques including powder X-ray diffraction (XRD), multinuclear solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, (29)Si{(1)H} 2D HETCOR (heteronuclear correlation) NMR spectroscopy, thermogravimetric analysis (TGA), and nitrogen sorption measurements. By using (13)C CPMAS NMR technique, the status of the incorporated thiol groups and their transformation to sulfonic acid groups can be monitored and, as an extension, to define the optimum conditions to be used for the oxidation reaction to be quantitative. In particular, (29)Si{(1)H} 2D HETCOR NMR revealed that the protons in sulfonic acid groups are in close proximity to the silanol Q(3) species, but not close enough to form a hydrogen bond.

  15. Preparation of a carbon-based solid acid catalyst by sulfonating activated carbon in a chemical reduction process.

    PubMed

    Liu, Xiao-Yan; Huang, Miao; Ma, Hai-Long; Zhang, Zeng-Qiang; Gao, Jin-Ming; Zhu, Yu-Lei; Han, Xiao-Jin; Guo, Xiang-Yun

    2010-10-18

    Sulfonated (SO(3)H-bearing) activated carbon (AC-SO(3)H) was synthesized by an aryl diazonium salt reduction process. The obtained material had a SO(3)H density of 0.64 mmol·g-1 and a specific surface area of 602 m2·g-1. The catalytic properties of AC-SO(3)H were compared with that of two commercial solid acid catalysts, Nafion NR50 and Amberlyst-15. In a 10-h esterification reaction of acetic acid with ethanol, the acid conversion with AC-SO(3)H (78%) was lower than that of Amberlyst-15 (86%), which could be attributed to the fact that the SO(3)H density of the sulfonated carbon was lower than that of Amberlyst-15 (4.60 mmol·g-1). However, AC-SO(3)H exhibited comparable and even much higher catalytic activities than the commercial catalysts in the esterification of aliphatic acids with longer carbon chains such as hexanoic acid and decanoic acid, which may be due to the large specific surface area and mesoporous structures of the activated carbon. The disadvantage of AC-SO(3)H is the leaching of SO(3)H group during the reactions.

  16. Acid-Base Interactions of Polystyrene Sulfonic Acid in Amorphous Solid Dispersions Using a Combined UV/FTIR/XPS/ssNMR Study.

    PubMed

    Song, Yang; Zemlyanov, Dmitry; Chen, Xin; Nie, Haichen; Su, Ziyang; Fang, Ke; Yang, Xinghao; Smith, Daniel; Byrn, Stephen; Lubach, Joseph W

    2016-02-01

    This study investigates the potential drug-excipient interactions of polystyrene sulfonic acid (PSSA) and two weakly basic anticancer drugs, lapatinib (LB) and gefitinib (GB), in amorphous solid dispersions. Based on the strong acidity of the sulfonic acid functional group, PSSA was hypothesized to exhibit specific intermolecular acid-base interactions with both model basic drugs. Ultraviolet (UV) spectroscopy identified red shifts, which correlated well with the color change observed in lapatinib-PSSA solutions. Fourier transform infrared (FTIR) spectra suggest the protonation of the quinazoline nitrogen atom in both model compounds, which agrees well with data from the crystalline ditosylate salt of lapatinib. X-ray photoelectron spectroscopy (XPS) detected increases in binding energy of the basic nitrogen atoms in both lapatinib and gefitinib, strongly indicating protonation of these nitrogen atoms. (15)N solid-state NMR spectroscopy provided direct spectroscopic evidence for protonation of the quinazoline nitrogen atoms in both LB and GB, as well as the secondary amine nitrogen atom in LB and the tertiary amine nitrogen atom in GB. The observed chemical shifts in the LB-PSSA (15)N spectrum also agree very well with the lapatinib ditosylate salt where proton transfer is known. Additionally, the dissolution and physical stability behaviors of both amorphous solid dispersions were examined. PSSA was found to significantly improve the dissolution of LB and GB and effectively inhibit the crystallization of LB and GB under accelerated storage conditions due to the beneficial strong intermolecular acid-base interaction between the sulfonic acid groups and basic nitrogen centers.

  17. Synthesis and properties of poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid)/PbS hybrid composite

    SciTech Connect

    Preda, N.; Rusen, E.; Musuc, A.; Enculescu, M.; Matei, E.; Marculescu, B.; Fruth, V.; Enculescu, I.

    2010-08-15

    The synthesis of a new hybrid composite based on PbS nanoparticles and poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid) [P(MMA-AMPSA)] copolymer is reported. The chemical synthesis consists in two steps: (i) a surfactant-free emulsion copolymerization between methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid and (ii) the generation of PbS particles in the presence of the P(MMA-AMPSA) latex, from the reaction between lead nitrate and thiourea. The composite was studied by scanning electron microscopy (SEM), X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The microstructure observed using SEM proves that the PbS nanoparticles are well dispersed in the copolymer matrix. The X-ray diffraction measurements demonstrate that the PbS nanoparticles have a cubic rock salt structure. It was also found that the inorganic semiconductor nanoparticles improve the thermal stability of the copolymer matrix.

  18. Photochemical degradation of sunscreen agent 2-phenylbenzimidazole-5-sulfonic acid in different water matrices.

    PubMed

    Ji, Yuefei; Zhou, Lei; Zhang, Ya; Ferronato, Corinne; Brigante, Marcello; Mailhot, Gilles; Yang, Xi; Chovelon, Jean-Marc

    2013-10-01

    The occurrence of sunscreen agents in natural environment is of scientific concern recently due to their potential risk to ecology system and human beings as endocrine disrupting chemicals (EDCs). In this work the photodegradation mechanism and pathways of sunscreen agent 2-phenylbenzimidazole-5-sulfonic acid (PBSA) were investigated under artificial solar irradiation with the goal of assessing the potential of photolysis as a transformation mechanism in aquatic environments. The quantum yield of PBSA direct photolysis in pH 6.8 buffer solution under filtered mercury lamp irradiation was determined as 2.70 × 10(-4). Laser flash photolysis (LFP) experiments confirmed the involvement of PBSA radical cation (PBSA(·+)) during direct photolysis. Acidic or basic condition facilitated PBSA direct photolysis in aqueous solution. Indirect photolysis out-competes direct photolysis as a major process for PBSA attenuation only at higher level of photosensitizers (e.g., NO3(-) > 2 mM). Thus, direct photolysis is likely to be the major loss pathway responsible for the elimination of PBSA in natural sunlit surface waters, while indirect photolysis (e.g., mediated by HO·) appeared to be less important due to a general low level of steady-state concentration of HO· ([HO·]ss) in natural surface waters. Direct photolysis pathways of PBSA includes desulfonation and benzimidazole ring cleavage, which are probably initiated by the excited triplet state ((3)PBSA*) and radical cation (PBSA(·+)). Conversely, hydroxylation products of PBSA and 2-phenyl-1H-benzimidazole as well as their ring opening intermediates were found in nitrate-induced PBSA photolysis, suggesting the indirect photodegradation was primarily mediated by HO and followed a different mechanism.

  19. Use of anionic clays for photoprotection and sunscreen photostability: Hydrotalcites and phenylbenzimidazole sulfonic acid

    NASA Astrophysics Data System (ADS)

    Perioli, Luana; Ambrogi, Valeria; Rossi, Carlo; Latterini, Loredana; Nocchetti, Morena; Costantino, Umberto

    2006-05-01

    Layered double hydroxides of hydrotalcite (HTlc) type have many applications as matrices in pharmaceutical and cosmetic fields when intercalated with active species in anionic form. The aim of this work was to intercalate 2-phenyl-1H-benzimidazole-5-sulfonic acid (Eusolex 232) (EUS) as sunscreen molecule into hydrotalcites in order to obtain the sunscreen stabilization, the reduction of its photodegradation and the elimination of close contact between skin and filter. Hydrotalcites MgAl and ZnAl were used as hosts and the intercalation products obtained were characterized by TG, RX and DSC. They were also submitted to spectrophotometric assays in order to study the matrix influence on sunlight protection and on sunscreen photostability. These experiments showed that both MgAl and ZnAl HTlc intercalation products maintained the sunscreen properties and eusolex photodegradation was reduced. The in vitro EUS release from both formulations was almost negligible when compared with formulations containing free EUS. The EUS intercalation in HTlc and the respective formulations provided advantages in the maintenance of photoprotection efficacy, filter photostabilization and avoidance of a close contact between skin and filter, with consequent elimination of allergy problems and photocross reactions.

  20. Removal of emerging perfluorooctanoic acid and perfluorooctane sulfonate contaminants from lake water.

    PubMed

    Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Sarker, Dipok Chandra; Suja, Fatihah

    2016-10-11

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the major polyfluoroalkyl substances (PFASs) contaminating global water environment. This study investigated the efficiency of granular activated carbon (GAC), ultrafiltration (UF) and nanofiltration (NF) treatment for removing PFOS and PFOA contaminants from lake water. NF gave greater removal of all contaminant types (in terms of organic matter, PFOS and PFOA) than GAC treatment which in turn was greater than UF treatment. The lower removal by UF was due to larger pore size of the membrane compared to the size of the target contaminants. For all treatment processes, lower pH (4) in the feedwater showed greater rejection of the organics and selected PFASs. This was likely due to increase in the electrostatic repulsion between solute and sorbent. It could be observed that on increasing the concentration of organics in the feed solution, the rejection of PFOA/PFOS decreased which was due to competition between organics and PFOS/PFOA for binding sites on the membrane/activated carbon surface. It was also noted that protein content led to greater influence for lower rejection of the PFOA/PFOS than carbohydrate or DOC content. This study demonstrated the potential use of membrane processes for removing emerging persistent organic pollutant removal from lake water.

  1. Removal of textile dyes and metallic ions using polyelectrolytes and macroelectrolytes containing sulfonic acid groups.

    PubMed

    Caldera Villalobos, M; Peláez Cid, A A; Herrera González, Ana M

    2016-07-15

    This work reports the removal of textile dyes and metallic ions by means of adsorption and coagulation-flocculation using two polyelectrolytes and two macroelectrolytes containing sulfonic acid groups. The adsorption of textile dyes was studied in aqueous solutions containing cationic dyes and in wastewater containing a vat dye. Also, removal of vat and naphthol dyes was studied using the process of coagulation-flocculation. The results show these materials possess elevated adsorption capacity, and they accomplished removal rates above 97% in aqueous solutions. The removal of the vat dye improved the quality of the wastewater notably, and an uncolored effluent was obtained at the end of the treatment. The treatment using adsorption decreased the values for coloration, conductivity, suspended solids, and pH. The removal of vat and naphthol dyes by means of coagulation-flocculation was studied as well, and removal rates of 90% were obtained. The polyelectrolytes and macroelectrolytes also proved effective in the adsorption of metallic ions in wastewater. The treatment using adsorption accomplished high removal rates of metallic ions, and it showed greater selectivity towards Cu(2+), Fe(3+) and Pb(2+). A decrease in the content of solids as well as the values for COD and conductivity was observed in the wastewater as well. The analyses of FT-IR indicated that cationic dyes and metallic ions were chemisorbed by means of ionic exchange.

  2. Spontaneous modification of graphite anode by anthraquinone-2-sulfonic acid for microbial fuel cells.

    PubMed

    Tang, Xinhua; Li, Haoran; Du, Zhuwei; Ng, How Yong

    2014-07-01

    In this study, anthraquinone-2-sulfonic acid (AQS), an electron transfer mediator, was immobilized onto graphite felt surface via spontaneous reduction of the in situ generated AQS diazonium cations. Cyclic voltammetry (CV) and energy dispersive spectrometry (EDS) characterizations of AQS modified graphite demonstrated that AQS was covalently grafted onto the graphite surface. The modified graphite, with a surface AQS concentration of 5.37 ± 1.15 × 10(-9)mol/cm(2), exhibited good electrochemical activity and high stability. The midpoint potential of the modified graphite was about -0.248 V (vs. normal hydrogen electrode, NHE), indicating that electrons could be easily transferred from NADH in bacteria to the electrode. AQS modified anode in MFCs increased the maximum power density from 967 ± 33 mW/m(2) to 1872 ± 42 mW/m(2). These results demonstrated that covalently modified AQS functioned as an electron transfer mediator to facilitate extracellular electron transfer from bacteria to electrode and significantly enhanced the power production in MFCs.

  3. Aquatic predicted no-effect-concentration derivation for perfluorooctane sulfonic acid.

    PubMed

    Qi, Ping; Wang, Ying; Mu, Jingli; Wang, Juying

    2011-04-01

    Perfluorooctane sulfonic acid (PFOS), a representative perfluorinated surfactant, is an anthropogenic pollutant detected in various environmental and biological matrices. Some laboratory and field work has been conducted to assess the aquatic toxicity of PFOS, but little is known regarding its toxicity threshold to the aquatic ecosystem. In the present study, predicted no-effect concentrations (PNECs) were derived by four different approaches. The interspecies correlation estimation (ICE) program and final acute-to-chronic ratio (FACR) were applied to the development of PNEC based on the toxic mode of action (MOA) of PFOS. By comparison of the different PNECs, the recommended aquatic toxicity thresholds for PFOS are in the range of 0.61 to 6.66 µg/L. Based on comparison of PNEC values, microcosm results, and reported environmental concentrations, PFOS appears not to pose a serious threat to aquatic organisms. The present results demonstrate that MOA is an important consideration for the derivation of reliable PNECs; moreover, the ICE-based species sensitivity distribution (SSD) method can be used to derive PNECs when toxicological data are limited. The application of MOA and ICE for deriving PNEC values in the present study may facilitate studies on using a combination of quantitative structure-activity relationship (QSAR) models and ICE to estimate PNECs.

  4. Formation and transport of the sulfonic acid metabolites of alachlor and metolachlor in soil

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.

    2001-01-01

    Alachlor and metolachlor are dechlorinated and transformed into their corresponding ethane sulfonic acid (ESA) metabolites in soil. In a field-disappearance study, it was shown that alachlor ESA was formed at a faster rate and at concentrations 2-4 times higher than metolachlor ESA, conforming with the observed longer disappearance half-life of metolachlor (15.5 d) in the field as compared to alachlor (8 d). Runoff data also showed higher concentrations of alachlor ESA as compared to metolachlor ESA, even though they were applied at the same levels. Data from soil cores showed transport of the ESA compounds in soil to as far down as 75-90 cm below the surface, at concentrations ranging from less than 0.5 ??g/L to about 50 ??g/L. In contrast, no parent herbicide was detected at these depths. This observation correlates with the higher log KOC values for alachlor (3.33) and metolachlor (3.01) relative to their corresponding ESA metabolites, alachlor ESA (2.26), and metolachlor ESA (2.29).

  5. Human Exposure and Elimination Kinetics of Chlorinated Polyfluoroalkyl Ether Sulfonic Acids (Cl-PFESAs).

    PubMed

    Shi, Yali; Vestergren, Robin; Xu, Lin; Zhou, Zhen; Li, Chuangxiu; Liang, Yong; Cai, Yaqi

    2016-03-01

    The incomplete mass-balance of organic fluorine in human serum indicates the existence of unknown per- and polyfluoroalkyl substances (PFASs) with persistent and bioaccumulative properties. Here we characterized human exposure and elimination kinetics of chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) in metal plating workers (n = 19), high fish consumers (n = 45), and background controls (n = 8). Cl-PFESAs were detected in >98% of the sampled individuals with serum concentrations ranging <0.019-5040 ng/mL. Statistically higher median serum levels were observed in high fish consumers (93.7 ng/mL) and metal plating workers (51.5 ng/mL) compared to the background control group (4.78 ng/mL) (Kruskal-Wallis rank sum test, p < 0.01). Cl-PFESAs could account for 0.269 to 93.3% of ∑PFASs in human serum indicating that this compound class may explain a substantial fraction of previously unidentified organic fluorine in the Chinese population. Estimated half-lives for renal clearance (median 280 years; range 7.1-4230 years) and total elimination (median 15.3 years; range 10.1-56.4 years) for the eight carbon Cl-PFESA suggest that this is the most biopersistent PFAS in humans reported to date. The apparent ubiquitous distribution and slow elimination kinetics in humans underscore the need for more research and regulatory actions on Cl-PFESAs and PFAS alternatives with similar chemical structures.

  6. Laccase-catalyzed bisphenol A oxidation in the presence of 10-propyl sulfonic acid phenoxazine.

    PubMed

    Ivanec-Goranina, Rūta; Kulys, Juozas; Bachmatova, Irina; Marcinkevičienė, Liucija; Meškys, Rolandas

    2015-04-01

    The kinetics of the Coriolopsis byrsina laccase-catalyzed bisphenol A (BisA) oxidation was investigated in the absence and presence of electron-transfer mediator 3-phenoxazin-10-yl-propane-1-sulfonic acid (PPSA) at pH5.5 and 25°C. It was shown that oxidation rate of the hardly degrading compound BisA increased in the presence of the highly reactive substrate PPSA. The increase of reaction rate depends on PPSA and BisA concentrations as well on their ratio, e.g., at 0.2 mmol/L of BisA and 2 μmol/L of PPSA the rate increased 2 times. The kinetic data were analyzed using a scheme of synergistic laccase-catalyzed BisA oxidation. The calculated constant, characterizing reactivity of PPSA with laccase, is almost 1000 times higher than the constant, characterizing reactivity of BisA with laccase. This means that mediator-assisted BisA oxidation rate can be 1000 times higher in comparison to non-mediator reaction if compounds concentration is equal but very low.

  7. Assessment of Perfluorooctane Sulfonate and Perfluorooctanoic Acid Exposure Through Fish Consumption in Italy

    PubMed Central

    Barbarossa, Andrea; Gazzotti, Teresa; Farabegoli, Federica; Mancini, Francesca R.; Zironi, Elisa; Busani, Luca; Pagliuca, Giampiero

    2016-01-01

    Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are pollutants of anthropic origin with possible side effects on human health. Diet, and in particular fish and seafood, is considered the major intake pathway for humans. The present study investigated the levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination in twenty-five samples of fresh fillet of five widely consumed fish species purchased from large retailers in Italy, to be used for an estimation of the Italian population exposure to these contaminants. PFOS and PFOA were found in all samples, at concentrations up to 1896 (mean=627 ng/kg) and 487 ng/kg (mean = 75 ng/kg), respectively, confirming the role of fish as high contributor to human exposure. However, a remarkable inter-species variability was observed, and multiple factors were suggested as potentially responsible for such differences, suggesting that the preferential consumption of certain species could likely increase the intake, and thus the exposure. The exposure estimates for both average and high fish consumers resulted far below the tolerable daily intakes for PFOS and PFOA in all age groups, confirming the outcomes of EFSA’s scientific report. In particular, the calculated total dietary exposure for the 95th percentile consumers belonging to the toddler age class, the most exposed group, resulted equal to 9.72 ng/kg body weight (BW)/day for PFOS and 8.39 ng/kg BW/day for PFOA. PMID:28058243

  8. Colorimetric detection of Cd2+ using 1-amino-2-naphthol-4-sulfonic acid functionalized silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Huang, Pengcheng; Liu, Bowen; Jin, Weiwei; Wu, Fangying; Wan, Yiqun

    2016-11-01

    A colorimetric assay has been developed for facile, rapid, and sensitive detection of Cd2+ using 1-amino-2-naphthol-4-sulfonic acid functionalized silver nanoparticles (ANS-AgNPs). The presence of Cd2+ induces the aggregation of ANS-AgNPs through cooperative metal-ligand interaction. As a result, the characteristic surface plasmon resonance (SPR) peak of ANS-AgNPs at 390 nm was red-shifted to 580 nm, yielding a color change from bright yellow to reddish-brown. The color change is monitored by UV-Vis spectrometer and can be directly read out by the naked eye. Under the optimized conditions, a good linear relationship (correlation coefficient R = 0.997) was obtained between the ratio of the absorbance at 580 nm to that at 390 nm (A580nm/A390nm) and the concentration of Cd2+ over the range of 1.0-10 μM with detection limit of 87 nM. The proposed method is simple and efficient, which has been applied for determining Cd2+ in milk powder, serum, and lake water with satisfactory results.

  9. Toxicological evaluation of peroxy sulfonated oleic acid (PSOA) in subacute and developmental toxicity studies.

    PubMed

    Pechacek, Nathan; Laidlaw, Karen; Clubb, Stephanie; Aulmann, Walter; Osorio, Magdalena; Caudill, Jeff

    2013-12-01

    Peroxy sulfonated oleic acid (PSOA) is a new coupler used in sanitizing solutions primarily for the food and beverage industry. The toxicity of PSOA was evaluated in a 28-day repeat dose study according to OECD 407 guidelines with a 14-day recovery period and a developmental toxicity study according to OECD 414 guidelines. In both studies, PSOA was administered once daily via gavage at 0, 5, 15 and 50 mg/kg/day to Sprague-Dawley rats. Due to its corrosive properties, the highest test concentration was restricted to 0.5%. No findings related to PSOA administration were observed for the 28-day repeat-dose study and the NOEL is 50 mg/kg/day. Additionally, no impairment of the mucous membranes of the gastrointestinal tract was observed up to 0.5%, which is considered the NOEC in terms of local toxicity. For the developmental study, an embryo-fetal NOEL of 50 mg/kg/day was identified and the maternal NOEL is considered to be 15 mg/kg/day, based on slight reductions in maternal body weight and food consumption, as well as a modest increase in the incidence of clinical observations at the high dose. These findings demonstrate that PSOA appears to have minimal potential to induce toxicity associated with repeat-dose or developmental exposures.

  10. Sulfotanone, a new alkyl sulfonic acid derivative from Streptomyces sp. IFM 11694 with TRAIL resistance-overcoming activity.

    PubMed

    Abdelfattah, Mohamed S; Ishikawa, Naoki; Karmakar, Utpal K; Ishibashi, Masami

    2016-04-01

    One new alkyl sulfonic acid derivative, sulfotanone (1), and the known panosialin wA (2) were isolated from the methanolic extract of mycelium of Streptomyces sp. 11694. The structure of the new compound (1) was established by a combination of spectroscopic techniques, including HRESIMS, IR, 1D and 2D NMR measurements. Compound 1 (40 µM) in combination with TRAIL showed synergistic activity in sensitizing TRAIL-resistance in human gastric adenocarcinoma cell lines.

  11. Gene Expression Profiling in the Liver and Lung of Perfluorooctane Sulfonate-Exposed Mouse Fetuses: Comparison to Changes Induced by Exposure to Perfluorooctanoic Acid

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are environmental contaminants found in the tissues of humans and wildlife. They are activators of peroxisome proliferator-activated receptor-alpha (PPARα) and exhibit hepatocarcinogenic potential in rats. PFOS...

  12. Sulfonic acid functionalized silica: an efficient heterogeneous catalyst for a three-component synthesis of 1,4-dihydropyridines under solvent-free conditions.

    PubMed

    Das, Biswanath; Suneel, Kanaparthy; Venkateswarlu, Katta; Ravikanth, Bommena

    2008-03-01

    Sulfonic acid functionalized silica catalyzed the three-component reaction of aromatic amines, alpha,beta-unsaturated aldehydes and beta-keto esters forming the corresponding 1,4-dihydropyridines in short reaction times and in high yields.

  13. Syntheses, crystal structures and antioxidant study of Zn(II) complexes with morin-5'-sulfonic acid (MSA).

    PubMed

    Pieniążek, Elżbieta; Kalembkiewicz, Jan; Dranka, Maciej; Woźnicka, Elżbieta

    2014-12-01

    The study of modified synthetic procedure of water soluble morin-5'-sulfonic acid sodium salt (NaMSA) involving less aggressive chemicals and carried out at mild conditions was described. The NaMSA salt is a convenient source of anionic morin-5'-sulfonic ligand (MSA) in ion exchange reactions. The coordination ability of MSA ligand towards the zinc cations was investigated in aqueous solution and in solid state. Novel zinc complexes of morin-5'-sulfonate were obtained by a reaction of Zn(NO3)2 with morin-5'-sulfonate in water. Resulting compounds were characterized by single-crystal X-ray diffraction analysis, as well as spectral and thermal methods. The coordination interaction, hydrogen bond and π-π stacking lead to the formation of a 1D chain or 3D coordination polymers. The antioxidant activity of the Zn(II)-MSA complexes was evaluated by means of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. In this work, we have shown that the studied compounds are more effective free radical scavengers than the natural flavonoids like plain morin.

  14. Occurrence of Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Milk and Yogurt and Their Risk Assessment

    PubMed Central

    Xing, Zhenni; Lu, Jianjiang; Liu, Zilong; Li, Shanman; Wang, Gehui; Wang, Xiaolong

    2016-01-01

    Although perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been identified in milk and dairy products in many regions, knowledge on their occurrence in Xinjiang (China) is rare. This study was conducted to measure the levels of PFOA and PFOS in milk and yogurt from Xinjiang and to investigate the average daily intake (ADI) of these two compounds. PFOA and PFOS levels were analyzed using ultrasonic extraction with methanol and solid-phase extraction followed by liquid chromatography–mass spectrometry. Retail milk and yogurt samples present higher detection rates (39.6% and 48.1%) and mean concentrations (24.5 and 31.8 ng/L) of PFOS than those of PFOA (33.0% and 37.0%; 16.2 and 22.6 ng/L, respectively). For raw milk samples, only PFOS was detected. The differences in the levels of the two compounds between samples from the north and south regions were observed, and northern regions showed higher pollution levels than southern regions. On the basis of the retail milk measurements and consumption data, the ADIs of PFOA and PFOS for Xinjiang adults were calculated to be 0.0211 and 0.0318 ng/kg/day, respectively. Furthermore, the estimated intakes of PFOA and PFOS varied among different groupings (age, area, gender, and race) and increased with increasing age. Relevant hazard ratios were found to be far less than 1.0, and this finding suggested that no imminent health damages were produced by PFOA and PFOS intake via milk and yogurt consumption in the Xinjiang population. PMID:27775680

  15. Pistacia lentiscus resin regulates intestinal damage and inflammation in trinitrobenzene sulfonic acid-induced colitis.

    PubMed

    Gioxari, Aristea; Kaliora, Andriana C; Papalois, Apostolos; Agrogiannis, George; Triantafillidis, John K; Andrikopoulos, Nikolaos K

    2011-11-01

    Mastic (Pistacia lentiscus) of the Anacardiaceae family has exhibited anti-inflammatory and antioxidant properties in patients with Crohn's disease. This study was based on the hypothesis that mastic inhibits intestinal damage in inflammatory bowel disease, regulating inflammation and oxidative stress in intestinal epithelium. Four different dosages of P. lentiscus powder in the form of powder were administered orally to trinitrobenzene sulfonic acid-induced colitic rats. Eighty-four male Wistar rats were randomly assigned to seven groups: A, control; B, colitic; C-F, colitic rats daily supplemented with P. lentiscus powder at (C) 50 mg/kg, (D) 100 mg/kg, (E) 200 mg/kg, and (F) 300 mg/kg of body weight; and G, colitic rats treated daily with cortisone (25 μg/kg of body weight). Colonic damage was assessed microscopically. The cytokines tumor necrosis factor-α, intercellular adhesion molecule-1 (ICAM-1), interleukin (IL)-6, IL-8, and IL-10 and malonaldehyde were measured in colonic specimens. Results were expressed as mean ± SE values. Histological amelioration of colitis (P≤.001) and significant differences in colonic indices occurred after 3 days of treatment. Daily administration of 100 mg of P. lentiscus powder/kg of body weight decreased all inflammatory cytokines (P≤.05), whereas 50 mg of P. lentiscus powder/kg of body weight and cortisone treatment reduced only ICAM-1 (P≤.05 and P≤.01, respectively). Malonaldehyde was significantly suppressed in all treated groups (P≤.01). IL-10 remained unchanged. Cytokines and malonaldehyde remained unaltered after 6 days of treatment. Thus P. lentiscus powder could possibly have a therapeutic role in Crohn's disease, regulating oxidant/antioxidant balance and modulating inflammation.

  16. Toxicity of perfluorooctane sulfonate and perfluorooctanoic acid to plants and aquatic invertebrates.

    PubMed

    Li, Mei-Hui

    2009-02-01

    Acute toxicities of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were tested on four freshwater species and three plant species. PFOS was more toxic than PFOA for all species tested in this study. Similar time-response patterns of PFOS and PFOA toxicity were observed for each tested species. Values of the 48-h LC(50) of PFOS for all test species ranged from 27 to 233 mg/L and values of the 96-h LC(50) for three of the species ranged from 10 to 178 mg/L. Values of the 48-h LC(50) of PFOA for all test species ranged from 181 to 732 mg/L and values of the 96-h LC(50) for three of the species ranged from 337 to 672 mg/L. The most sensitive freshwater species to PFOS was green neon shrimp (Neocaridina denticulate) with a 96-h LC(50) of 10 mg/L. Of the aquatic organisms tested, the aquatic snail (Physa acuta) always has the highest resistance to PFOS or PFOA toxicity over each exposure period. Both PFOS and PFOA had no obvious adverse effect on seed germination for all three plant species. Five-day EC(50) of root elongation was more sensitive to LC(50) of seed germination in this study. Based on EC(10), EC(50), and NOECs, the 5-day root elongation sensitivity of test plants to both PFOS and PFOA was in the order of lettuce (Lactuca sativa) > pakchoi (Brassica rapa chinensis) > cucumber (Cucumis sativus). Based on the results of this study and other published literature, it is suggested that current PFOS and PFOA levels in freshwater may have no acute harmful ecological impact on the aquatic environment. However, more research on the long-term ecological effects of PFOS and PFOA on aquatic fauna are needed to provide important information to adequately assess ecological risk of PFOS and PFOA.

  17. Dual Role of Endogenous Serotonin in 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis

    PubMed Central

    Rapalli, Alberto; Bertoni, Simona; Arcaro, Valentina; Saccani, Francesca; Grandi, Andrea; Vivo, Valentina; Cantoni, Anna M.; Barocelli, Elisabetta

    2016-01-01

    Background and Aims: Changes in gut serotonin (5-HT) content have been described in Inflammatory Bowel Disease (IBD) and in different experimental models of colitis: the critical role of this monoamine in the pathogenesis of chronic gastrointestinal inflammation is gradually emerging. Aim of the present study was to evaluate the contribution of endogenous 5-HT through the activation of its specific receptor subtypes to the local and systemic inflammatory responses in an experimental model of IBD. Materials and Methods: Colitis was induced by intrarectal 2,4,6-TriNitroBenzene Sulfonic acid in mice subacutely treated with selective antagonists of 5-HT1A (WAY100135), 5-HT2A (Ketanserin), 5-HT3 (Ondansetron), 5-HT4 (GR125487), 5-HT7 (SB269970) receptors and with 5-HT1A agonist 8-Hydroxy-2-(di-n-propylamino)tetralin. Results: Blockade of 5-HT1A receptors worsened TNBS-induced local and systemic neutrophil recruitment while 5-HT1A agonist delayed and mitigated the severity of colitis, counteracting the increase in colonic 5-HT content. On the contrary, blockade of 5-HT2A receptors improved global health conditions, reduced colonic morphological alterations, down-regulated neutrophil recruitment, inflammatory cytokines levels and colonic apoptosis. Antagonism of 5-HT3, 5-HT4, and 5-HT7 receptor sites did not remarkably affect the progression and outcome of the pathology or only slightly improved it. Conclusion: The prevailing deleterious contribution given by endogenous 5-HT to inflammation in TNBS-induced colitis is seemingly mediated by 5-HT2A and, to a lesser extent, by 5-HT4 receptors and coexists with the weak beneficial effect elicited by 5-HT1A stimulation. These findings suggest how only a selective interference with 5-HT pro-inflammatory actions may represent an additional potential therapeutic option for intestinal inflammatory disorders. PMID:27047383

  18. Validation and optimization of experimental colitis induction in rats using 2, 4, 6-trinitrobenzene sulfonic acid

    PubMed Central

    Motavallian-Naeini, A.; Andalib, S.; Rabbani, M.; Mahzouni, P.; Afsharipour, M.; Minaiyan, M.

    2012-01-01

    Trinitrobenzene sulfonic acid (TNBS)-induced colitis is one of the most common methods for studying inflammatory bowel disease in animal models. Several factors may, however, affect its reproducibility, rate of animal mortality, and macroscopic and histopathological outcomes. Our aim was to validate the main contributing factors to this method and compare the effects of different reference drugs upon remission of resultant colon injuries. TNBS was dissolved in 0.25 ml of ethanol (50% v/v) and instilled (25, 50, 100 and 150 mg/kg) intracolonically to the male Wistar rats. After determination of optimum dose of TNBS in male rats and assessment of this dose in female rats, they were treated with reference drugs including dexamethasone [1 mg/kg, intraperitoneally (i.p.) and 2 mg/kg, orally (p.o.)], Asacol (mesalazine, 100 mg/kg, p.o.; 150 mg/kg, enema) and hydrocortisone acetate (20 mg/kg, i.p.; 20 mg/kg, enema) which started 2 h after colitis induction and continued daily for 6 consecutive days. Thereafter, macroscopic and microscopic parameters and clinical features were assessed and compared in different groups. We found that the optimum dose of TNBS for the reproducibility of colonic damage with the least mortality rate was 50 mg/kg. Amongst studied reference drugs, hydrocortisone acetate (i.p.), dexamethasone (i.p. and p.o.) and Asacol (p.o.) significantly diminished the severity of macroscopic and microscopic injuries and could be considered effective for experimental colitis studies in rats . Our findings suggest that optimization of TNBS dose is essential for induction of colitis under the laboratory conditions; and gender exerts no impact upon macroscopic and histological characteristics of TNBS-induced colitis in rats. Furthermore, the enema forms of hydrocortisone and Asacol are not appropriate reference drugs. PMID:23181094

  19. Penicillanic acid sulfone: interaction with RTEM beta-lactamase from Escherichia coli at different pH values.

    PubMed

    Kemal, C; Knowles, J R

    1981-06-23

    The interaction of the sulfone of penicillanic acid with the TEM-2 beta-lactamase from Escherichia coli has been investigated as a function of pH between pH 7.0 and 9.6. The first-formed acyl-enzyme suffers one of three fates: deacylation, tautomerization to a bound enamine that transiently inhibited the enzyme, and a process (possibly transimination) that leads to enzyme inactivation. The observed changes in ultraviolet absorbance are consistent with the initially observed product of deacylation being the enamine tautomer (4) of the imine from malonsemialdehyde and penicillamine sulfinate. The same enamine can be generated nonenzymically from the sulfone at high pH. The transiently inhibited enzyme appears to be the same enamine attached to the enzyme by an ester linkage. The rather complex kinetic behavior can be deconvuluted by exploiting the effect of pH on the partitioning of the acyl-enzyme between deacylation and the transiently inhibited form of the enzyme. The pathways followed by penicillanic acid sulfone provide a model for the behavior of a number of other reagents that inactivate the beta-lactamase.

  20. Nanostructured bacterial cellulose-poly(4-styrene sulfonic acid) composite membranes with high storage modulus and protonic conductivity.

    PubMed

    Gadim, Tiago D O; Figueiredo, Andrea G P R; Rosero-Navarro, Nataly C; Vilela, Carla; Gamelas, José A F; Barros-Timmons, Ana; Neto, Carlos Pascoal; Silvestre, Armando J D; Freire, Carmen S R; Figueiredo, Filipe M L

    2014-05-28

    The present study reports the development of a new generation of bio-based nanocomposite proton exchange membranes based on bacterial cellulose (BC) and poly(4-styrene sulfonic acid) (PSSA), produced by in situ free radical polymerization of sodium 4-styrenesulfonate using poly(ethylene glycol) diacrylate (PEGDA) as cross-linker, followed by conversion of the ensuing polymer into the acidic form. The BC nanofibrilar network endows the composite membranes with excellent mechanical properties at least up to 140 °C, a temperature where either pure PSSA or Nafion are soft, as shown by dynamic mechanical analysis. The large concentration of sulfonic acid groups in PSSA is responsible for the high ionic exchange capacity of the composite membranes, reaching 2.25 mmol g(-1) for a composite with 83 wt % PSSA/PEGDA. The through-plane protonic conductivity of the best membrane is in excess of 0.1 S cm(-1) at 94 °C and 98% relative humidity (RH), decreasing to 0.042 S cm(-1) at 60% RH. These values are comparable or even higher than those of ionomers such as Nafion or polyelectrolytes such as PSSA. This combination of electric and viscoelastic properties with low cost underlines the potential of these nanocomposites as a bio-based alternative to other polymer membranes for application in fuel cells, redox flow batteries, or other devices requiring functional proton conducting elements, such as sensors and actuators.

  1. Induction of chronic pancreatic disease by trinitrobenzene sulfonic acid infusion into rat pancreatic ducts.

    PubMed

    Puig-Diví, V; Molero, X; Salas, A; Guarner, F; Guarner, L; Malagelada, J R

    1996-11-01

    Despite being a common disease in humans, little is known about the etiopathogenesis of and effective therapeutic approaches to chronic pancreatitis, due mainly to the fact that few simple animal models suitable to study inflammatory and fibrogenetic processes have been described in the pancreas. Trinitrobenzene sulfonic acid (TNBS) induces chronic colitis and cholangitis in the rat. We hypothesized that TNBS instillation into the pancreatic ducts could also result in the development of a chronic pancreatic disease. The biliopancreatic duct of rats was cannulated and tied close to the liver. TNBS [0.4 ml of 2% TNBS in phosphate-buffered saline (PBS)-10% ethanol, pH 8] was infused into the pancreas under a continuous controlled-pressure system. Control rats underwent the same procedure using vehicle only. Pathology assessment of TNBS-treated rats examined at 48 h was consistent with severe acute necrotizing pancreatitis, having a morality rate of 31% and serum amylase activity of 37.4 +/- 8.8 U/ml at 24 h and 13.3 +/- 1.7 U/ml at 48 h (p < 0.01 for both time points compared to PBS/ethanol-treated rats). Groups of 10 rats each were killed at 3, 4, and 6 week after the surgical procedure. Morphological examination revealed changes mimicking features of chronic pancreatitis in humans in 80% (32 of 40) of TNBS-treated rats, consisting in various degrees of periductal and lobular fibrosis, duct stenosis, patchy acute and chronic inflammatory cell infiltrates, and signs of gland atrophy. Animals developing chronic disease had a weight gain rate significantly lower than that of control rats. Serum amylase, fasting glucose, and a glucose tolerance test were not different in diseased or control rats. In conclusion, we were able to induce chronic fibrogenetic inflammatory disease in the pancreas after a single pulse instillation of TNBS into the pancreatic ducts. This might be a useful animal model to study the pathophysiology of inflammatory, fibrogenetic, and reparative

  2. Theoretical investigation on the molecular inclusion process of prilocaine into p-sulfonic acid calix[6]arene

    NASA Astrophysics Data System (ADS)

    de Sousa, Sara M. R.; Fernandes, Sergio A.; De Almeida, Wagner B.; Guimarães, Luciana; Abranches, Paula A. S.; Varejão, Eduardo V. V.; Nascimento, Clebio S., Jr.

    2016-02-01

    The present letter reports, for the first time, results from a theoretical analysis of the inclusion process involving the prilocaine into the p-sulfonic acid calix[6]arene. Structure and stabilization energies were calculated, in both gas and aqueous phases, using a sequential methodology based on semiempirical and Density Functional Theory (DFT) calculations. From the results, a qualitative structure property relationship could be established with some main structural features being relevant for inclusion complex stabilization: (i) the hydrogen bonds established between guest and host molecules, (ii) the dispersion effect and (iii) the inclusion mode of guest molecule into the host cavity.

  3. Covalently bonded sulfonic acid magnetic graphene oxide: Fe3O4@GO-Pr-SO3H as a powerful hybrid catalyst for synthesis of indazolophthalazinetriones.

    PubMed

    Doustkhah, Esmail; Rostamnia, Sadegh

    2016-09-15

    Multistep synthesis of covalently sulfonated magnetic graphene oxide was achieved by starting from Hummer's method to produce graphene oxide (GO) from chemical oxidation of graphite. Then, GO nanosheets were applied to support Fe3O4 nanoparticles (Fe3O4@GO) using co-precipitation method in the presence of GO sheets. This strategy led to formation of uniform particles of Fe3O4 on the surface of GO sheets. Then, it was sulfonated (Fe3O4@GO-Pr-SO3H) through modification with 3-mercaptopropyltrimethoxysilane (MPTMS) and subsequent oxidation with hydrogen peroxide (H2O2). In comparison, the covalently bonded propyl sulfonic acid groups were more prevailing rather to sulfonic acids of GO itself. The proposed catalyst was more active and recyclable at least for 11 runs.

  4. Ion-exclusion chromatographic behavior of aliphatic carboxylic acids and benzenecarboxylic acids on a sulfonated styrene--divinylbenzene co-polymer resin column with sulfuric acid containing various alcohols as eluent.

    PubMed

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi

    2003-05-16

    The addition of C1-C7 alcohols (methanol, ethanol, propanol, butanol, heptanol, hexanol and heptanol) to dilute sulfuric acid as eluent in ion-exclusion chromatography using a highly sulfonated styrene-divinylbenzene co-polymer resin (TSKgel SCX) in the H+ form as the stationary phase was carried out for the simultaneous separations of both (a) C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, 2-methylvaleric, isocaproic, caproic, 2,2-dimethyl-n-valeric, 2-methylhexanoic, 5-methylhexanoic and heptanoic acids) and (b) benzenecarboxylic acids (pyromellitic, hemimellitic, trimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic and salicylic acids and phenol). Heptanol was the most effective modifier in ion-exclusion chromatography for the improvement of peak shapes and a reduction in retention volumes for higher aliphatic carboxylic acids and benzenecarboxylic acids. Excellent simultaneous separation and relatively highly sensitive conductimetric detection for these C1-C7 aliphatic carboxylic acids were achieved on the TSKgel SCX column (150 x 6 mm I.D.) in 30 min using 0.5 mM sulfuric acid containing 0.025% heptanol as eluent. Excellent simultaneous separation and highly sensitive UV detection at 200 nm for these benzenecarboxylic acids were also achieved on the TSKgel SCX column in 30 min using 5 mM sulfuric acid containing 0.075% heptanol as eluent.

  5. Proparacaine complexation with beta-cyclodextrin and p-sulfonic acid calix[6]arene, as evaluated by varied (1)H-NMR approaches.

    PubMed

    Arantes, Lucas Micquéias; Scarelli, Camilla; Marsaioli, Anita Jocelyne; de Paula, Eneida; Fernandes, Sergio Antonio

    2009-09-01

    This study focused on the use of NMR techniques as a tool for the investigation of complex formation between proparacaine and cyclodextrins (CDs) or p-sulfonic acid calix[6]arene. The pH dependence of the complexation of proparacaine with beta-CD and p-sulfonic acid calix[6]arene was studied and binding constants were determined by (1)H NMR spectroscopy [diffusion-ordered spectroscopy (DOSY)] for the charged and uncharged forms of the local anesthetic in beta-CD and p-sulfonic acid calix[6]arene. The stoichiometries of the complexes was determined and rotating frame Overhauser enhancement spectroscopy (ROESY) 1D experiments revealed details of the molecular insertion of proparacaine into the beta-CD and p-sulfonic acid calix[6]arene cavities. The results unambiguously demonstrate that pH is an important factor for the development of supramolecular architectures based on beta-CD and p-sulfonic acid calix[6]arene as the host molecules. Such host-guest complexes were investigated in view of their potential use as new therapeutic formulations, designed to increase the bioavailability and/or to decrease the systemic toxicity of proparacaine in anesthesia procedures.

  6. Development and validation of an automated static headspace gas chromatography-mass spectrometry (SHS-GC-MS) method for monitoring the formation of ethyl methane sulfonate from ethanol and methane sulfonic acid.

    PubMed

    Jacq, Karine; Delaney, Ed; Teasdale, Andrew; Eyley, Steve; Taylor-Worth, Karen; Lipczynski, Andrew; Reif, Van D; Elder, David P; Facchine, Kevin L; Golec, Simon; Oestrich, Rolf Schulte; Sandra, Pat; David, Frank

    2008-12-15

    An automated sample preparation and analysis procedure was developed to monitor the formation of ethyl methane sulfonate from reaction mixtures containing ethanol and methane sulfonic acid. The system is based on a liquid handling robot combined with a static headspace module. The formed ethyl methane sulfonate is analysed after derivatisation with pentafluorothiophenol using static headspace-gas chromatography-mass spectrometry (SHS-GC-MS). Using the automated reaction-derivatisation-headspace GC-MS system, the formation of ethyl methane sulfonate can be monitored in different reaction mixtures under different reaction conditions, including temperature, water content and pH. Excellent linearity, repeatability and robustness were obtained, allowing the system to be used in kinetic studies.

  7. Design of a highly efficient and water-tolerant sulfonic acid nanoreactor based on tunable ordered porous silica for the von Pechmann reaction.

    PubMed

    Karimi, Babak; Zareyee, Daryoush

    2008-09-18

    Among a number of different sulfonic acid nanoreactors prepared, 5 having both acidic sites and phenyl groups located inside the mesochannels of SBA-15 was shown to be the most active and reusable catalyst in the von Pechmann reaction. The mesochannels, and covalently anchored organic groups, provide a synergistic means of an efficient approach of the reactants to acidic sites, enough space for the subsequent cyclization, and suitable hydrophobicity to drive out the water byproduct.

  8. Enhanced bio-decolorization of 1-amino-4-bromoanthraquinone-2-sulfonic acid by Sphingomonas xenophaga with nutrient amendment.

    PubMed

    Lu, Hong; Guan, Xiaofan; Wang, Jing; Zhou, Jiti; Zhang, Haikun

    2015-01-01

    Bacterial decolorization of anthraquinone dye intermediates is a slow process under aerobic conditions. To speed up the process, in the present study, effects of various nutrients on 1-amino-4-bromoanthraquinone-2-sulfonic acid (ABAS) decolorization by Sphingomonas xenophaga QYY were investigated. The results showed that peptone, yeast extract and casamino acid amendments promoted ABAS bio-decolorization. In particular, the addition of peptone and casamino acids could improve the decolorization activity of strain QYY. Further experiments showed that l-proline had a more significant accelerating effect on ABAS decolorization compared with other amino acids. l-Proline not only supported cell growth, but also significantly increased the decolorization activity of strain QYY. Membrane proteins of strain QYY exhibited ABAS decolorization activities in the presence of l-proline or reduced nicotinamide adenine dinucleotide, while this behavior was not observed in the presence of other amino acids. Moreover, the positive correlation between l-proline concentration and the decolorization activity of membrane proteins was observed, indicating that l-proline plays an important role in ABAS decolorization. The above findings provide us not only a novel insight into bacterial ABAS decolorization, but also an l-proline-supplemented bioaugmentation strategy for enhancing ABAS bio-decolorization.

  9. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA): emerging contaminants of increasing concern in fish from Lake Varese, Italy.

    PubMed

    Squadrone, S; Ciccotelli, V; Prearo, M; Favaro, L; Scanzio, T; Foglini, C; Abete, M C

    2015-07-01

    Perfluoroalkylated substances (PFASs) are highly fluorinated aliphatic compounds with high thermal and chemical stability, used in a range of industrial applications. Extensive screening analyses in biota samples from all over the world have shown the bioaccumulation of PFAS into higher trophic levels in the food chain. Perfluorooctane sulfonic acid (PFOS) and perfluoroctanoic acid (PFOA) are potential reproductive and developmental toxicants and are considered to be emerging endocrine disrupters. Ingestion of fish and other seafood is considered the main source of exposure of these contaminants. Here, we quantified PFOS and PFOA by LC-MS/MS in muscle samples of European perch from Lake Varese, Italy. PFOS was detected in all samples with concentrations of up to 17.2 ng g(-1). Although the reported values were lower than the recommended total daily intake (TDI) proposed by the European Food Safety Authority (EFSA), fish from Lake Varese may be a significant source of dietary PFOS exposure.

  10. bFGF interaction and in vivo angiogenesis inhibition by self-assembling sulfonic acid-based copolymers.

    PubMed

    García-Fernández, L; Aguilar, M R; Ochoa-Callejero, L; Abradelo, C; Martínez, A; San Román, J

    2012-01-01

    The antiangiogenic activity of different families of biocompatible and non-toxic polymer drugs based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or polymethacrylic derivatives of 5-aminonaphthalen sulfonic acid (MANSA) is analyzed using directed in vivo angiogenesis assay and correlated with in vitro results. These active compounds were copolymerized with butylacrylate (BA) and N-vinylpyrrolidone in order to obtain two families of copolymers with different properties in aqueous media. The most hydrophobic copolymers poly(BA-co-MANSA) and poly(BA-co-AMPS) formed amphiphilic copolymers and presented micellar morphology in aqueous media. This supramolecular organization of the copolymers had a clear effect on bioactivity. Poly(BA-co-MANSA) copolymers showed the best antiangiogenic activity and very low toxicity at relatively low dose, with the possibility to be injected directly in the solid tumors alone or in combination with other therapeutic agents such as anti-VEGF drugs. The obtained results demonstrate that not only the chemical structure but also the supramolecular organization of the macromolecules plays a key role in the anti-angiogenic activity of these active polymers.

  11. Preparation of water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups and their micelles behavior, anticoagulant effect and cytotoxicity.

    PubMed

    Han, Qiaorong; Chen, Xiaohan; Niu, Yanlian; Zhao, Bo; Wang, Bingxiang; Mao, Chun; Chen, Libin; Shen, Jian

    2013-07-02

    Biocompatibility of nanoparticles has been attracting great interest in the development of nanoscience and nanotechnology. Herein, the aliphatic water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups (HBPE-SO3 NPs) were synthesized and characterized. They are amphiphilic polymeric nanoparticles with hydrophobic hyperbranched polyester (HBPE) core and hydrophilic sulfonic acid terminal groups. Based on our observations, we believe there are two forms of HBPE-SO3 NPs in water under different conditions: unimolecular micelles and large multimolecular micelles. The biocompatibility and anticoagulant effect of the HBPE-SO3 NPs were investigated using coagulation tests, hemolysis assay, morphological changes of red blood cells (RBCs), complement and platelet activation detection, and cytotoxicity (MTT). The results confirmed that the sulfonic acid terminal groups can substantially enhance the anticoagulant property of HBPE, and the HBPE-SO3 NPs have the potential to be used in nanomedicine due to their good bioproperties.

  12. Gas chromatography/mass spectrometric analysis of methyl esters of N,N-dialkylaminoethane-2-sulfonic acids for verification of the Chemical Weapons Convention.

    PubMed

    Pardasani, Deepak; Gupta, Arvinda K; Palit, Meehir; Shakya, Purushottam; Kanaujia, Pankaj K; Sekhar, K; Dubey, Devendra K

    2005-01-01

    This paper describes the synthesis and gas chromatography/electron ionization mass spectrometric (GC/EI-MS) analysis of methyl esters of N,N-dialkylaminoethane-2-sulfonic acids (DAESAs). These sulfonic acids are important environmental signatures of nerve agent VX and its toxic analogues, hence GC/EI-MS analysis of their methyl esters is of paramount importance for verification of the Chemical Weapons Convention. DAESAs were prepared by condensation of 2-bromoethane sulfonic acid with dialkylamines, and by condensation of dialkylaminoethyl chloride with sodium bisulfite. GC/EI-MS analysis of methyl esters of DAESAs yielded mass spectra; based on these spectra, generalized fragmentation routes are proposed that rationalize most of the characteristic ions.

  13. A new strategy for the synthesis of taurine derivatives using the 'safety-catch' principle for the protection of sulfonic acids.

    PubMed

    Seeberger, Sonja; Griffin, Roger J; Hardcastle, Ian R; Golding, Bernard T

    2007-01-07

    The safety-catch principle has been applied for the development of a new method for protecting sulfonic acids. 2,2-Dimethylsuccinic acid was reduced to 2,2-dimethylbutane-1,4-diol, which was selectively silylated to give 4-(tert-butyldiphenylsilanyloxy)-2,2-dimethylbutan-1-ol. Reaction of the latter compound with 2-chloroethanesulfonyl chloride in the presence of triethylamine afforded 4-(tert-butyldiphenylsilyloxy)-2,2-dimethylbutyl ethenesulfonate directly. The ethenesulfonate underwent Michael-type addition with secondary amines to give protected derivatives of taurine (2-aminoethanesulfonic acid). Deprotection was achieved on treatment with tetrabutylammonium fluoride, whereby cleavage of the silicon-oxygen bond led to an intermediate alkoxide that immediately cyclised to 2,2-dimethyltetrahydrofuran with liberation of a sulfonate. Pure sulfonic acids were obtained from the crude product by ion exchange chromatography on a strongly basic resin, which was eluted with aqueous acetic acid. The method developed should be generally applicable to the protection of sulfonic acids and is amenable to a multiparallel format.

  14. Versatile acetylation of carbohydrate substrates with bench-top sulfonic acids and application to one-pot syntheses of peracetylated thioglycosides.

    PubMed

    Chao, Chin-Sheng; Chen, Min-Chun; Lin, Shih-Che; Mong, Kwok-Kong T

    2008-04-07

    Inexpensive and readily available sulfonic acids, p-toluenesulfonic acid, and sulfuric acid are versatile and efficient catalysts for the peracetylation of a broad spectrum of carbohydrate substrates in good yield and in a practical time frame. Three appealing features in sulfonic acid-catalyzed acetylation of free sugars were explored including (1) suppression of furanosyl acetate formation for D-galactose and L-fucose; (2) high yielding chemoselective acetylation of sialic acid under appropriate conditions; and (3) peracetylation of amino sugars with different amino protecting functions. Simple one-pot two step acetylation-thioglycosidation methods for the expeditious synthesis of p-tolyl per-O-acetyl thioglycosides were also delineated.

  15. Identification, Tissue Distribution, and Bioaccumulation Potential of Cyclic Perfluorinated Sulfonic Acids Isomers in an Airport Impacted Ecosystem.

    PubMed

    Wang, Yuan; Vestergren, Robin; Shi, Yali; Cao, Dong; Xu, Lin; Cai, Yaqi; Zhao, Xiaoli; Wu, Fengchang

    2016-10-18

    The use of cyclic perfluoroalkyl acids as anticorrosive agents in hydraulic fluids remains a poorly characterized source of organofluorine compounds to the environment. Here, we investigated the presence of perfluoroethylenecyclohexanesulfonate (PFECHS) isomers in environmental samples for the first time using a combination of high resolution and tandem mass spectrometry. Five distinct peaks attributed to different isomers of PFECHS and perfluoropropylcyclopentanesulfonate (PFPCPeS) were identified in environmental samples. The sum of PFECHS and PFPCPeS isomers displayed logarithmically decreasing spatial trends in water (1.04-324 ng/L) and sediment samples (sulfonic acid group affect the bioaccumulation potential of cyclic perfluoroalkyl acids. Based on the high mobility and moderate bioaccumulation potential of cyclic perfluorinated acids it is suggested that contamination of aquifers used for drinking water around airports may be a hitherto overlooked problem for this novel class of contaminants.

  16. Morphology Tailoring of Sulfonic Acid Functionalized Organosilica Nanohybrids for the Synthesis of Biomass-Derived Alkyl Levulinates.

    PubMed

    An, Sai; Song, Daiyu; Lu, Bo; Yang, Xia; Guo, Yi-Hang

    2015-07-20

    Morphology evolution of sulfonic acid functionalized organosilica nanohybrids (Si(Et)Si-Pr/ArSO3 H) with a 1D tubular structure (inner diameter of ca. 5 nm), a 2D hexagonal mesostructure (pore diameter of ca. 5 nm), and a 3D hollow spherical structure (shell thickness of 2-3 nm and inner diameter of ca. 15 nm) was successfully realized through P123-templated sol-gel cocondensation strategies and fine-tuning of the acidity followed by aging or a hydrothermal treatment. The Si(Et)Si-Pr/ArSO3 H nanohybrids were applied in synthesis of alkyl levulinates from the esterification of levulinic acid and ethanolysis of furfural alcohol. Hollow spherical Si(Et)Si-Pr/ArSO3 H and hexagonal mesoporous analogues exhibited the highest and lowest catalytic activity, respectively, among three types of nanohybrids; additionally, the activity was influenced by the -SO3 H loading. The activity differences are explained in terms of different Brønsted acid and textural properties, reactant/product diffusion, and mass transfer rate, as well as accessibility of -SO3 H sites to the reactant molecules. The reusability of the nanohybrids was also evaluated.

  17. Catalytic Upgrading of bio-oil using 1-octene and 1-butanol over sulfonic acid resin catalysts

    SciTech Connect

    Zhang, Zhijun; Wang, Qingwen; Tripathi, Prabhat; Pittman, Charles U.

    2011-02-04

    Raw bio-oil from fast pyrolysis of biomass must be refined before it can be used as a transporation fuel, a petroleum refinery feed or for many other fuel uses. Raw bio-oil was upgraded with the neat model olefin, 1-octene, and with 1-octene/1-butanol mixtures over sulfonic acid resin catalysts frin 80 to 150 degrees celisus in order to simultaneously lower water content and acidity and to increase hydrophobicity and heating value. Phase separation and coke formation were key factors limiting the reaction rate during upgrading with neat 1-octene although octanols were formed by 1-octene hydration along with small amounts of octyl acetates and ethers. GC-MS analysis confirmed that olefin hydration, carboxylic acid esterification, acetal formation from aldehydes and ketones and O- and C-alkylations of phenolic compounds occurred simultaneously during upgrading with 1-octene/1-butanol mixtures. Addition of 1-butanol increased olefin conversion dramatically be reducing mass transfer restraints and serving as a cosolvent or emulsifying agent. It also reacted with carboxylic acids and aldehydes/ketones to form esters, and acetals, respectively, while also serving to stabilize bio-oil during heating. 1-Butanol addition also protected the catalysts, increasing catalyst lifetime and reducing or eliminationg coking. Upgrading sharply increased ester content and decreased the amounts of levoglucosan, polyhydric alcohols and organic acids. Upgrading lowered acidity (pH value rise from 2.5 to >3.0), removed the uppleasant ordor and increased hydrocarbon solubility. Water content decreased from 37.2% to < 7.5% dramatically and calorific value increased from 12.6 MJ kg to about 30.0 MJ kg.

  18. Method development and optimization on cinchona and chiral sulfonic acid-based zwitterionic stationary phases for enantiomer separations of free amino acids by high-performance liquid chromatography.

    PubMed

    Zhang, Tong; Holder, Emilie; Franco, Pilar; Lindner, Wolfgang

    2014-10-10

    CHIRALPAK ZWIX(+) and ZWIX(-) are cinchona alkaloid-derived zwitterionic chiral stationary phases (CSPs) containing a chiral sulfonic acid motif which serves as negatively charged interaction site. They are versatile for direct enantiomer resolution of amino acids and many other ampholytic compounds by HPLC. The synergistic double ion-pairing between the zwittrionic chiral selector and the ampholyte is the basis for interaction and chiral recognition mechanisms. ZWIX(+) and ZWIX(-) type CSPs or columns behave pseudo-enantiomerically and provide the feature of reversing enantiomer elution order by column switching. In the current study, extensive experimental work was carried out with the aim of developing schemes for an efficient generic screening and proposing straightforward approaches for method optimization on these ZWIX columns. Various chromatographic parameters were investigated using a large series of diverse amino acids and analogues for the purpose. The role of methanol (MeOH) as the protic solvent in the mobile phase is confirmed to be essential. The presence of water in a low percentage is beneficial for peak shape, resolution, analysis speed, sample solubility and MS detection performance. The involvement of acetonitrile (ACN) or tetrahydrofuran (THF) can help for adjusting retention time and selectivity. Incorporation of a suitable pair of acidic-basic additives at a right ratio in the mobile phase is determinant as well for the double ion-pairing mechanism. 50 mM formic acid+25 mM diethylamine (or ammonium hydroxide) in MeOH/ACN/H₂O and in MeOH/THF/H₂O at 49:49:2 (by volume) are recommended as the starting mobile phases for method development. Some other parameters are also considered in the proposed scheme to achieve successful enantioselective or stereoselective separation of the ampholytes.

  19. Synthesis and properties of reprocessable sulfonated polyimides cross-linked via acid stimulation for use as proton exchange membranes

    NASA Astrophysics Data System (ADS)

    Zhang, Boping; Ni, Jiangpeng; Xiang, Xiongzhi; Wang, Lei; Chen, Yongming

    2017-01-01

    Cross-linked sulfonated polyimides are one of the most promising materials for proton exchange membrane (PEM) applications. However, these cross-linked membranes are difficult to reprocess because they are insoluble. In this study, a series of cross-linkable sulfonated polyimides with flexible pendant alkyl side chains containing trimethoxysilyl groups is successfully synthesized. The cross-linkable polymers are highly soluble in common solvents and can be used to prepare tough and smooth films. Before the cross-linking reaction is complete, the membranes can be reprocessed, and the recovery rate of the prepared films falls within an acceptable range. The cross-linked membranes are obtained rapidly when the cross-linkable membranes are immersed in an acid solution, yielding a cross-linking density of the gel fraction of greater than 90%. The cross-linked membranes exhibit high proton conductivities and tensile strengths under hydrous conditions. Compared with those of pristine membranes, the oxidative and hydrolytic stabilities of the cross-linked membranes are significantly higher. The CSPI-70 membrane shows considerable power density in a direct methanol fuel cell (DMFC) test. All of these results suggest that the prepared cross-linked membranes have great potential for applications in proton exchange membrane fuel cells.

  20. Syn-Selective Synthesis of β-Branched α-Amino Acids by Alkylation of Glycine-Derived Imines with Secondary Sulfonates.

    PubMed

    Lou, Sha; McKenna, Grace M; Tymonko, Steven A; Ramirez, Antonio; Benkovics, Tamas; Conlon, David A; González-Bobes, Francisco

    2015-10-16

    A syn-selective synthesis of β-branched α-amino acids has been developed based on the alkylation of glycine imine esters with secondary sulfonates. The potassium counterion for the enolate, the solvent, and the leaving group on the electrophile were key levers to maximize the diasteroselectivity of the alkylation. The optimized conditions enabled a straightforward preparation of a number of β-branched α-amino acids that can be challenging to obtain.

  1. Using a Macroporous Silver Shell to Coat Sulfonic Acid Group-Functionalized Silica Spheres and Their Applications in Catalysis and Surface-Enhanced Raman Scattering.

    PubMed

    Ren, Guohong; Wang, Wenqin; Shang, Mengying; Zou, Hanzhi; Cheng, Shengwei

    2015-09-29

    In this paper, novel organic sulfonic acid group-functionalized silica spheres (SiO2-SO3H) were chosen as a template for fabricating core-shell SiO2-SO3H@Ag composite spheres by the seed-mediated growth method. The SiO2-SO3H spheres could be obtained easily by oxidation of the thiol group-terminated silica spheres (SiO2-SH) with H2O2. Due to the presence of sulfonic acid groups, the [Ag(NH3)2](+) ions were captured on the surface of the silica spheres, followed by in-site reduction to silver nanoseeds for further growth of the silver shell. By this strategy, the complete silver shell could be obtained, and the surface morphologies and structures of the silver shell could be controlled by adjusting the number of sulfonic acid groups on the silica spheres. A large number of sulfonic acid groups on the SiO2-SO3H spheres favored the formation of the macroporous silver shell, which was unique and exhibited good catalytic performance and a high surface-enhanced Raman scattering (SERS) enhancement ability.

  2. Global analysis of myocardial peptides containing cysteines with irreversible sulfinic and sulfonic acid post-translational modifications.

    PubMed

    Paulech, Jana; Liddy, Kiersten A; Engholm-Keller, Kasper; White, Melanie Y; Cordwell, Stuart J

    2015-03-01

    Cysteine (Cys) oxidation is a crucial post-translational modification (PTM) associated with redox signaling and oxidative stress. As Cys is highly reactive to oxidants it forms a range of post-translational modifications, some that are biologically reversible (e.g. disulfides, Cys sulfenic acid) and others (Cys sulfinic [Cys-SO2H] and sulfonic [Cys-SO3H] acids) that are considered "irreversible." We developed an enrichment method to isolate Cys-SO2H/SO3H-containing peptides from complex tissue lysates that is compatible with tandem mass spectrometry (MS/MS). The acidity of these post-translational modification (pKa Cys-SO3H < 0) creates a unique charge distribution when localized on tryptic peptides at acidic pH that can be utilized for their purification. The method is based on electrostatic repulsion of Cys-SO2H/SO3H-containing peptides from cationic resins (i.e. "negative" selection) followed by "positive" selection using hydrophilic interaction liquid chromatography. Modification of strong cation exchange protocols decreased the complexity of initial flowthrough fractions by allowing for hydrophobic retention of neutral peptides. Coupling of strong cation exchange and hydrophilic interaction liquid chromatography allowed for increased enrichment of Cys-SO2H/SO3H (up to 80%) from other modified peptides. We identified 181 Cys-SO2H/SO3H sites from rat myocardial tissue subjected to physiologically relevant concentrations of H2O2 (<100 μm) or to ischemia/reperfusion (I/R) injury via Langendorff perfusion. I/R significantly increased Cys-SO2H/SO3H-modified peptides from proteins involved in energy utilization and contractility, as well as those involved in oxidative damage and repair.

  3. Combined Effect of Free Nitrous Acid Pretreatment and Sodium Dodecylbenzene Sulfonate on Short-Chain Fatty Acid Production from Waste Activated Sludge

    PubMed Central

    Zhao, Jianwei; Liu, Yiwen; Ni, Bingjie; Wang, Qilin; Wang, Dongbo; Yang, Qi; Sun, Yingjie; Zeng, Guangming; Li, Xiaoming

    2016-01-01

    Free nitrous acid (FNA) serving as a pretreatment is an effective approach to accelerate sludge disintegration. Also, sodium dodecylbenzene sulfonate (SDBS), a type of surfactants, has been determined at significant levels in sewage sludge, which thereby affects the characteristics of sludge. Both FNA pretreatment and sludge SDBS levels can affect short-chain fatty acid (SCFA) generation from sludge anaerobic fermentation. To date, however, the combined effect of FNA pretreatment and SDBS presence on SCFA production as well as the corresponding mechanisms have never been documented. This work therefore aims to provide such support. Experimental results showed that the combination of FNA and SDBS treatment not only improved SCFA accumulation but also shortened the fermentation time. The maximal SCFA accumulation of 334.5 mg chemical oxygen demand (COD)/g volatile suspended solids (VSS) was achieved at 1.54 mg FNA/L treatment and 0.02 g/g dry sludge, which was respectively 1.79-fold and 1.41-fold of that from FNA treatment and sludge containing SDBS alone. Mechanism investigations revealed that the combined FNA pretreatment and SDBS accelerated solubilization, hydrolysis, and acidification steps but inhibited the methanogenesis. All those observations were in agreement with SCFA enhancement. PMID:26868898

  4. Comparative hepatotoxicity of 6:2 fluorotelomer carboxylic acid and 6:2 fluorotelomer sulfonic acid, two fluorinated alternatives to long-chain perfluoroalkyl acids, on adult male mice.

    PubMed

    Sheng, Nan; Zhou, Xiujuan; Zheng, Fei; Pan, Yitao; Guo, Xuejiang; Guo, Yong; Sun, Yan; Dai, Jiayin

    2016-12-28

    Due to their structural similarities, 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA) are often used as alternatives to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), respectively. With limited health risk data and 6:2 FTSA detection in water and sludge, the toxicity of these chemicals is of growing concern. Here, adult male mice were exposed with 5 mg/kg/day of 6:2 FTCA or 6:2 FTSA for 28 days to investigate their hepatotoxicological effects. In contrast to 6:2 FTCA, 6:2 FTSA was detected at high and very high levels in serum and liver, respectively, demonstrating bioaccumulation potential and slow elimination. Furthermore, 6:2 FTSA induced liver weight increase, inflammation, and necrosis, whereas 6:2 FTCA caused no obvious liver injury, with fewer significantly altered genes detected compared with that of 6:2 FTSA (39 vs. 412). Although PFOA and PFOS commonly activate peroxisome proliferator-activated receptor α (PPARα), 6:2 FTSA induced an increase in PPARγ and related proteins, but not in lipid metabolism-related genes such as PPARα. Our results showed that 6:2 FTCA and 6:2 FTSA exhibited weak and moderate hepatotoxicity, respectively, compared with that reported for legacies PFOA and PFOS.

  5. Iron oxide nanoparticles immobilized to mesoporous NH2-SiO2 spheres by sulfonic acid functionalization as highly efficient catalysts

    NASA Astrophysics Data System (ADS)

    Zhang, Guoliang; Qin, Lei; Wu, Yujiao; Xu, Zehai; Guo, Xinwen

    2014-12-01

    A novel SiO2 nanosphere was synthesized by the post-synthetic grafting of sulfonic acid groups on to anionic-surfactant-templated mesoporous NH2-silica (AMAS). This one-pot post-functionalization strategy allowed more metal ions to be homogeneously anchored into the channel of the meso-SiO2 nanosphere. After hydrothermal and calcination treatment, the in situ growth of α-Fe2O3 on sulfonic acid-functionalized mesoporous NH2-SiO2 (SA-AMAS) exhibited much higher activity in the visible-light assisted Fenton reaction at neutral pH than that for AMAS or meso-SiO2 nanospheres. By analysis, the grafted sulfonic acid group can not only enhance the acid strength of the catalyst, but can also bring more orbital-overlapping between the active sites (FeII and FeIII) and the surface peroxide species, to facilitate the decomposition of H2O2 to hydroxyl radical. The present results provide opportunities for developing heterogeneous catalysts with high-performance in the field of green chemistry and environmental remediation.A novel SiO2 nanosphere was synthesized by the post-synthetic grafting of sulfonic acid groups on to anionic-surfactant-templated mesoporous NH2-silica (AMAS). This one-pot post-functionalization strategy allowed more metal ions to be homogeneously anchored into the channel of the meso-SiO2 nanosphere. After hydrothermal and calcination treatment, the in situ growth of α-Fe2O3 on sulfonic acid-functionalized mesoporous NH2-SiO2 (SA-AMAS) exhibited much higher activity in the visible-light assisted Fenton reaction at neutral pH than that for AMAS or meso-SiO2 nanospheres. By analysis, the grafted sulfonic acid group can not only enhance the acid strength of the catalyst, but can also bring more orbital-overlapping between the active sites (FeII and FeIII) and the surface peroxide species, to facilitate the decomposition of H2O2 to hydroxyl radical. The present results provide opportunities for developing heterogeneous catalysts with high-performance in the

  6. Synthesis of sulfonic acid derivatives by oxidative deprotection of thiols using tert-butyl hypochlorite.

    PubMed

    Joyard, Yoann; Papamicaël, Cyril; Bohn, Pierre; Bischoff, Laurent

    2013-05-03

    Starting from alkyl halides or Michael acceptors, thioacetates were prepared in situ and further treated with t-BuOCl, affording the corresponding sulfonyl chlorides which were trapped with nucleophiles such as water, alcohol, or amines. The three steps can be achieved in a one-pot procedure. Oxidative deprotection also proved to be efficient with S-trityl and S-tert-butyl groups, making it a convenient route toward cysteic acid derivatives.

  7. Synthesis and chelation properties of a new polymeric ligand derived from 1-amino-2-naphthol-4-sulfonic Acid.

    PubMed

    Manivannan, Dhanasekaran; Biju, Valsala Madhavan Nair

    2015-01-01

    A novel chelating resin for preconcentration of heavy metals from various seawater samples has been developed by condensing 1-amino-2-hydroxy-7-[(4-hydroxyphenyl)diazenyl] naphthalene-4-sulfonic acid (AHDNS) with formaldehyde (1:2 mole ratio) in the presence of oxalic acid as the catalyst. The resin thus obtained was used as a solid sorbent for the separation of divalent metal ions present at trace levels in seawater. The functionalized phenol (AHDNS) was characterized by spectral studies. The polymeric resin AHDNS-formaldehyde (AHDNS-F) obtained by condensing the functionalized phenol and formaldehyde was characterized by IR and NMR spectral studies. The chelating property of the AHDNS-F resin towards divalent metal ions was studied as a function of pH and in the presence of electrolyte. The metal uptake properties of the resin were determined by using an atomic absorption spectrophotometer. This procedure was validated for recovery of divalent metal ions from seawater samples. The recoveries of cadmium, cobalt, copper, manganese, lead, and zinc were above 92% under the optimum preconcentration conditions. The LOD was <0.73 μg/L and the RSDs were <2%. Thus, the AHDNS-F resin can be widely used as a solid sorbent for the preconcentration of trace metals at ppm levels in seawater samples.

  8. Simultaneous quantification of acetanilide herbicides and their oxanilic and sulfonic acid metabolites in natural waters.

    PubMed

    Heberle, S A; Aga, D S; Hany, R; Müller, S R

    2000-02-15

    This paper describes a procedure for simultaneous enrichment, separation, and quantification of acetanilide herbicides and their major ionic oxanilic acid (OXA) and ethanesulfonic acid (ESA) metabolites in groundwater and surface water using Carbopack B as a solid-phase extraction (SPE) material. The analytes adsorbed on Carbopack B were eluted selectively from the solid phase in three fractions containing the parent compounds (PCs), their OXA metabolites, and their ESA metabolites, respectively. The complete separation of the three compound classes allowed the analysis of the neutral PCs (acetochlor, alachlor, and metolachlor) and their methylated OXA metabolites by gas chromatography/mass spectrometry. The ESA compounds were analyzed by high-performance liquid chromatography with UV detection. The use of Carbopack B resulted in good recoveries of the polar metabolites even from large sample volumes (1 L). Absolute recoveries from spiked surface and groundwater samples ranged between 76 and 100% for the PCs, between 41 and 91% for the OXAs, and between 47 and 96% for the ESAs. The maximum standard deviation of the absolute recoveries was 12%. The method detection limits are between 1 and 8 ng/L for the PCs, between 1 and 7 ng/L for the OXAs, and between 10 and 90 ng/L for the ESAs.

  9. Dynamics of camphor sulfonic acid in polyaniline (PANI-CSA): a quasielastic neutron scattering study

    NASA Astrophysics Data System (ADS)

    Bée, M.; Djurado, D.; Combet, J.; Telling, M.; Rannou, P.; Pron, A.; Travers, J. P.

    2001-07-01

    PolyAniline (PANI) doped by camphor sulphonic acid (CSA) exhibits an electronic conductivity of several hundreds of S/cm. All the authors agree to invoke in various extents the role of disorder in the evolution of the transport properties as a function of temperature. The IRIS spectrometer at the Rutherford-Appleton Laboratory was used to remove uncertainties of previous IN6-IN16 experiments at Institut Laue-Langevin. The rigidity of the PANI chains was confirmed, in both a conducting and a partially doped sample. All the observable quasielastic scattering occurs from the CSA dynamics. However, this contribution is too weak in the case of the partially doped specimen to conclude about the coupling of the counter-ion disorder with the electronic transport properties.

  10. Formation of the bisulfite anion (HSO(3) (-) , m/z 81) upon collision-induced dissociation of anions derived from organic sulfonic acids.

    PubMed

    Jariwala, Freneil B; Wood, Ryan E; Nishshanka, Upul; Attygalle, Athula B

    2012-04-01

    In the negative-ion collision-induced dissociation mass spectra of most organic sulfonates, the base peak is observed at m/z 80 for the sulfur trioxide radical anion (SO(3) (-·) ). In contrast, the product-ion spectra of a few sulfonates, such as cysteic acid, aminomethanesulfonate, and 2-phenylethanesulfonate, show the base peak at m/z 81 for the bisulfite anion (HSO(3) (-) ). An investigation with an extensive variety of sulfonates revealed that the presence of a hydrogen atom at the β-position relative to the sulfur atom is a prerequisite for the formation of the bisulfite anion. The formation of HSO(3) (-) is highly favored when the atom at the β-position is nitrogen, or the leaving neutral species is a highly conjugated molecule such as styrene or acrylic acid. Deuterium-exchange experiments with aminomethanesulfonate demonstrated that the hydrogen for HSO(3) (-) formation is transferred from the β-position. The presence of a peak at m/z 80 in the spectrum of 2-sulfoacetic acid, in contrast to a peak at m/z 81 in that of 3-sulfopropanoic acid, corroborated the proposed hydrogen transfer mechanism. For diacidic compounds, such as 4-sulfobutanoic acid and cysteic acid, the m/z 81 ion can be formed by an alternative mechanism, in which the negative charge of the carboxylate moiety attacks the α-carbon relative to the sulfur atom. Experiments conducted with deuterium-exchanged and deuterium-labeled analogs of sulfocarboxylic acids demonstrated that the formation of the bisulfite anion resulted either from a hydrogen transfer from the β-carbon, or from a direct attack by the carboxylate moiety on the α-carbon.

  11. Temporal trends of perfluoroalkane sulfonic acids and their sulfonamide-based precursors in herring from the Swedish west coast 1991-2011 including isomer-specific considerations.

    PubMed

    Ullah, Shahid; Huber, Sandra; Bignert, Anders; Berger, Urs

    2014-04-01

    A method was developed for simultaneous analysis of perfluoroalkane sulfonic acids (PFSAs) and their sulfonamide-based precursors (perfluoroalkane sulfonamidoacetic acids (FASAAs), sulfonamides (FASAs), and sulfonamidoethanols (FASEs)) in fish muscle. Extraction was performed with acetonitrile followed by a clean-up and fractionation step and instrumental analysis by UPLC/MS/MS and GC/MS. Time trends of PFSAs and their precursors in herring muscle samples originating from the Kattegat at the west coast of Sweden were investigated covering the years 1991-2011. The following analytes were detected, all with decreasing or unchanged trends between 1991 and 2011: Perfluorobutane sulfonic acid (PFBS, below the method detection limit (sulfonic acid (PFHxS, 9-38pg/g), perfluorooctane sulfonic acid (PFOS, 240-930pg/g), perfluorodecane sulfonic acid (PFDS, acid (MeFOSAA and EtFOSAA, 2-39 and 2-31pg/g, respectively) and perfluorooctane sulfonamide (FOSA, 78-920pg/g). The highest concentrations were found for PFOS and FOSA around the turn of the century. Shorter disappearance half-lives were observed for precursors compared to PFSAs. Assuming that these trend differences are representative for fish consumed by the general Swedish population, this observation suggests that the relative contribution of precursors to total human exposure to PFOS via fish intake has decreased in Sweden over the study period. PFOS precursors in fish may have constituted a significant indirect exposure pathway for PFOS in the 1990s. Isomer-specific analysis of PFOS and FOSA revealed <10% relative contributions of branched isomers to total PFOS and total FOSA. Furthermore, the percentage branched isomers decreased over time for both compounds. These findings are contrary to patterns and temporal trends of PFOS isomers commonly found in human serum. In combination with literature data on isomer patterns

  12. Ion-exclusion chromatographic separations of C1-C6 aliphatic carboxylic acids on a sulfonated styrene-divinylbenzene co-polymer resin column with 5-methylhexanoic acid as eluent.

    PubMed

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi

    2003-05-16

    The application of C7 aliphatic carboxylic acids (heptanoic, 2-methylhexanoic, 5-methylhexanoic and 2,2-dimethyl-n-valeric acids) as eluents in ion-exclusion chromatography with conductimetric detection for C1-C6 aliphatic carboxylic acids (formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, isocaproic and caproic acids) was carried out using a highly sulfonated styrene-divinylbenzene co-polymer resin (TSKgel SCX) in the H+ form as a stationary phase. When using 0.05 mM sulfuric acid at pH 4.0 as the eluent, peak shapes of hydrophobic carboxylic acids (isovaleric, valeric, isocaproic and caproic acids) were tailed strongly. In contrast, when using 1 mM these C7 carboxylic acids at pH ca. 4 as the eluents, although system peaks (vacant peaks) corresponding to these C7 carboxylic acids appeared, peak shapes of these hydrophobic acids were improved drastically. Excellent simultaneous separation and relatively high sensitive conductimetric detection for these C1-C6 aliphatic carboxylic acids were achieved in 25 min on the TSKgel SCX column (150 x 6 mm I.D.) using 1 mM 5-methylhexanoic acid at pH 4.0 as the eluent.

  13. Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification.

    PubMed

    Muriithi, Beatrice; Loy, Douglas A

    2016-01-28

    The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%-30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%-42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes.

  14. Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification

    PubMed Central

    Muriithi, Beatrice; Loy, Douglas A.

    2016-01-01

    The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%–30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%–42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes. PMID:26828525

  15. A Comparative Ab Initio Study of the Primary Hydration and Proton Dissociation of Various Imide and Sulfonic Acid Ionomers

    SciTech Connect

    Clark II, Jeffrey K.; Paddison, Stephen J.; Eikerling, Michael; Dupuis, Michel; Zawodzinski, Jr., Thomas A.

    2012-03-29

    We compare the role of neighboring group substitutions on proton dissociation of hydrated acidic moieties suitable for proton exchange membranes through electronic structure calculations. Three pairs of ionomers containing similar electron withdrawing groups within the pair were chosen for the study: two fully fluorinated sulfonyl imides (CF3SO2NHSO2CF3 and CF3CF2SO2NHSO2CF3), two partially fluorinated sulfonyl imides (CH3SO2NHSO2CF3 and C6H5SO2NHSO2CF2CF3), and two aromatic sulfonic acid based material s (CH3C6H4SO3H and CH3 OC6 - H3OCH3C6H4SO3H). Fully optimized counterpoise (CP) corrected geometries were obtained for each ionomer fragment with the inclusion of water molecules at the B3LYP/6-311G** level of density functional theory. Spontaneous proton dissociation was observed upon addition of three water molecules in each system, and the transition to a solvent-separated ion pair occurred when four water molecules were introduced. No considerable quantitative or qualitative differences in proton dissociation, hydrogen bond networks formed, or water binding energies were found between systems containing similar electron withdrawing groups. Each of the sulfonyl imide ionomers exhibited qualitatively similar results regarding proton dissociation and separation. The fully fluorinated sulfonyl imides, however, showed a greater propensity to exist in dissociated and ion-pair separated states at low degrees of hydration than the partially fluorinated sulfonyl imides. This effect is due to the additional electron withdrawing groups providing charge stabilization as the dissociated proton migrates away from the imide anion.

  16. Modeling of boldine alkaloid adsorption onto pure and propyl-sulfonic acid-modified mesoporous silicas. A comparative study.

    PubMed

    Geszke-Moritz, Małgorzata; Moritz, Michał

    2016-12-01

    The present study deals with the adsorption of boldine onto pure and propyl-sulfonic acid-functionalized SBA-15, SBA-16 and mesocellular foam (MCF) materials. Siliceous adsorbents were characterized by nitrogen sorption analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy and thermogravimetric analysis. The equilibrium adsorption data were analyzed using the Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherms. Moreover, the Dubinin-Radushkevich and Dubinin-Astakhov isotherm models based on the Polanyi adsorption potential were employed. The latter was calculated using two alternative formulas including solubility-normalized (S-model) and empirical C-model. In order to find the best-fit isotherm, both linear regression and nonlinear fitting analysis were carried out. The Dubinin-Astakhov (S-model) isotherm revealed the best fit to the experimental points for adsorption of boldine onto pure mesoporous materials using both linear and nonlinear fitting analysis. Meanwhile, the process of boldine sorption onto modified silicas was described the best by the Langmuir and Temkin isotherms using linear regression and nonlinear fitting analysis, respectively. The values of adsorption energy (below 8kJ/mol) indicate the physical nature of boldine adsorption onto unmodified silicas whereas the ionic interactions seem to be the main force of alkaloid adsorption onto functionalized sorbents (energy of adsorption above 8kJ/mol).

  17. Inventory development for perfluorooctane sulfonic acid (PFOS) in Turkey: challenges to control chemicals in articles and products.

    PubMed

    Korucu, M Kemal; Gedik, Kadir; Weber, Roland; Karademir, Aykan; Kurt-Karakus, Perihan Binnur

    2015-10-01

    Perfluorooctane sulfonic acid (PFOS) and related substances have been listed as persistent organic pollutants (POPs) in the Stockholm Convention. Countries which have ratified the Convention need to take appropriate actions to control PFOS use and release. This study compiles and enhances the findings of the first inventory of PFOS and related substances use in Turkey conducted within the frame of the Stockholm Convention National Implementation Plan (NIP) update. The specific Harmonized Commodity Description and Coding System (Harmonized System (HS)) codes of imported and exported goods that possibly contain PFOS and 165 of Chemical Abstracts Service (CAS) numbers of PFOS-related substances were assessed for acquiring information from customs and other authorities. However, with the current approaches available, no useful information could be compiled since HS codes are not specific enough and CAS numbers are not used by customs. Furthermore, the cut-off volume in chemical databases in Turkey and the reporting limit in the HS system (0.1 %) are too high for controlling PFOS. The attempt of modeling imported volumes by a Monte Carlo simulation did not also result in a satisfactory estimate, giving an upper-bound estimate above the global production volumes. The replies to questionnaires were not satisfactory, highlighting that an elaborated approach is needed in the communication with potentially PFOS-using stakeholders. The experience of the challenges of gathering information on PFOS in articles and products revealed the gaps of controlling highly hazardous substances in products and articles and the need of improvements.

  18. Concentrating versus non-concentrating reactors for solar photocatalytic degradation of p-nitrotoluene-o-sulfonic acid.

    PubMed

    Parra, S; Malato, S; Blanco, J; Péringer, P; Pulgari, C

    2001-01-01

    The photocatalytic oxidation of the non-biodegradable p-nitrotoluene-o-sulfonic acid (p-NTS) in homogeneous (photo-Fenton reactions) and heterogeneous (with TiO2) solutions has been studied at a pilot-scale under solar irradiation at the Plataforma Solar de Almeria (PSA). In this study two different reactors were tested: a medium concentrating radiation system (Heliomans, HM) and a non-concentrating radiation system (CPC). Their advantages and disadvantages for p-NTS degradation have been compared and discussed. The degradation rates obtained in the CPC collector are around three times more efficient than in the HM collectors. However, in both systems, 100% of the initial concentration of p-NTS was removed. Kinetic experiments were performed in both systems using TiO2 suspensions. During the photodegradation, the disappearance of p-NTS was followed by HPLC, the mineralization of the solution by the TOC technique, the evolution of NO3-, NO2-, and SO4(2-) concentration by ionic chromatography, the toxicity by the standard Microtox test, and the biodegradability by BOD5 and COD measurements. The obtained results demonstrated the utility of the heterogeneous catalysis (using TiO2 as catalyst) as a pretreatment method that can be followed by a biological process.

  19. Bioaccumulation of perfluoroalkyl acids including the isomers of perfluorooctane sulfonate in carp (Cyprinus carpio) in a sediment/water microcosm.

    PubMed

    Fang, Shuhong; Zhang, Yifeng; Zhao, Shuyan; Qiang, Liwen; Chen, Meng; Zhu, Lingyan

    2016-12-01

    Carp (Cyprinus carpio) were exposed to perfluoroalkyl acids (PFAAs) including perfluorooctane sulfonate (PFOS) isomers in an artificially contaminated sediment/water microcosm. The uptake constant of PFAAs increased with increasing carbon chain length, whereas the elimination coefficient displayed the opposite trend, suggesting that carbon chain length plays an important role in the bioaccumulation of PFAAs. When the contribution of suspended particulate matter was taken into account, the bioaccumulation factors (BAFs) became lower (3.61-600 L/kg) compared with BAFs derived from only considering the absorption from free PFAAs in water (3.85-97000 L/kg). The results indicate that suspended particulate matter in water constitutes an important source of exposure for aquatic organisms to long-chain PFAAs. Linear (n-)PFOS was preferentially accumulated compared with branched isomers in carp. Among the branched isomers, 1m-PFOS displayed the greatest bioaccumulation, whereas m2 -PFOS had the lowest. Linear PFOS displayed greater partitioning ability from blood to other tissues over branched PFOS (br-PFOS) isomers, leading to a relatively lower n-PFOS proportion in blood. In summary, suspended particulate matter made a contribution to the accumulation of long-chain PFAAs in aquatic organisms, and n-PFOS was preferentially accumulated compared with br-PFOS isomers. Environ Toxicol Chem 2016;35:3005-3013. © 2016 SETAC.

  20. Effect of diameter of cellulosic nano-fiber on conductivity of poly(aniline sulfonic acid) composites

    NASA Astrophysics Data System (ADS)

    Konagaya, S.; Shimizu, K.; Terada, M.; Yamada, T.; Sanada, K.; Numata, O.; Sugino, G.

    2014-05-01

    The authors have been studying the effect of cellulosic nano-fiber (CeNF) with the diameter of less than 30 nm and the length of a few micrometers on the conductivity of the conductive polymer composites (PAS/PEs/CeNF) prepared from poly(aniline sulfonic acid) (PAS), a water dispersible polyester (PEs) and CeNF and confirmed that CeNF was effective for the enhancement of their conductivity, and that the conductivity enhancement was attributable to the strong adsorbing ability of CeNF to PAS molecules. Thiner CeNF has so larger surface area that it is expected to adsorb more PAS molecules on its surface, which possibly lead to further conductivity enhancement of the composites. The authors prepared thinner CeNF with the size of 16 nm by the use of ultrasonic dispersing machine. It was clarified that the thinner CeNF had a higher adsorbing ability to PAS molecules and a larger effect on the conductivity enhancement of PAS/PEs/CeNF composites.

  1. Spectrophotometric determination of procaine hydrochloride in pharmaceutical products using 1,2-naphthoquinone-4-sulfonic acid as the chromogenic reagent

    NASA Astrophysics Data System (ADS)

    Xu, Li Xiao; Shen, Yun Xiu; Wang, Huai You; Jiang, Ji Gang; Xiao, Yan

    2003-11-01

    Spectrophotometric determination of procaine hydrochloride is described. The procaine hydrochloride reacts with 1,2-naphthoquinone-4-sulfonic acid in pH 3.60 buffer solution to form a salmon pink compound, and its maximum absorption wavelength is at 484 nm, ɛ 484=5.22×10 3.The absorbance for procaine hydrochloride from 0.30 to 100 μg ml -1 obeys Beer's law. The linear regression equation of the calibration graph is C=19.23A-0.03, with a linear regression correlative coefficient is 0.9996, the detection limit is 0.28 μg ml -1; recovery is from 98.0 to 105.2%. Effects of pH, surfactant, organic solvent, foreign ions, and standing time on the determination of procaine hydrochloride have been examined. This method is rapid and simple, and can be used for the determination of procaine hydrochloride in injection solution of procaine hydrochloride. The results obtained by this method agreed with those by the official method (dead-stop titration).

  2. Benzocaine complexation with p-sulfonic acid calix[n]arene: experimental ((1) H-NMR) and theoretical approaches.

    PubMed

    Arantes, Lucas M; Varejão, Eduardo V V; Pelizzaro-Rocha, Karin J; Cereda, Cíntia M S; de Paula, Eneida; Lourenço, Maicon P; Duarte, Hélio A; Fernandes, Sergio A

    2014-05-01

    The aim of this work was to study the interaction between the local anesthetic benzocaine and p-sulfonic acid calix[n]arenes using NMR and theoretical calculations and to assess the effects of complexation on cytotoxicity of benzocaine. The architectures of the complexes were proposed according to (1) H NMR data (Job plot, binding constants, and ROESY) indicating details on the insertion of benzocaine in the cavity of the calix[n]arenes. The proposed inclusion compounds were optimized using the PM3 semiempirical method, and the electronic plus nuclear repulsion energy contributions were performed at the DFT level using the PBE exchange/correlation functional and the 6-311G(d) basis set. The remarkable agreement between experimental and theoretical approaches adds support to their use in the structural characterization of the inclusion complexes. In vitro cytotoxic tests showed that complexation intensifies the intrinsic toxicity of benzocaine, possibly by increasing the water solubility of the anesthetic and favoring its partitioning inside of biomembranes.

  3. Analysis of perfluorooctane sulfonate and perfluorooctanoic acid with a mixed-mode coating-based solid-phase microextraction fiber.

    PubMed

    Chen, Chunyan; Wang, Jianping; Yang, Shaolei; Yan, Zhihong; Cai, Qingyun; Yao, Shouzhuo

    2013-09-30

    A novel mixed-mode coating-based solid-phase microextraction (SPME) fiber was prepared by chemical bonding dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride and 3-(trimethoxysilyl)-1-propanamine, the sol-gel precursors, on an anodized Ti wire, aiming to effectively adsorb perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). The anodized Ti wire with uniform TiO2 nanotube arrays provides high mechanical strength and strong adhesion to the mixed-mode coating. The prepared fiber shows excellent organic solvent stability due to the covalent bonding between the coating and the fiber, and significantly higher extraction efficiency than the commercial fibers, 100 μm polydimethylsiloxane and 85 μm polyacrylate fiber, due to the synergistic extraction effects of the coating functional groups. Good linearity (R(2)=0.9994 for PFOS, R(2)=0.9992 for PFOA) was obtained with detection limits of 2.5 and 7.5 pg mL(-1) for PFOS and PFOA, respectively. Recoveries were in the range of 88%-102%. The proposed method was successfully applied in the analysis of PFOS and PFOA in a local river with the results of 0.05 and 0.06 ng mL(-1), respectively.

  4. Astragaloside IV ameliorates 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis implicating regulation of energy metabolism.

    PubMed

    Jiang, Xu-Guang; Sun, Kai; Liu, Yu-Ying; Yan, Li; Wang, Ming-Xia; Fan, Jing-Yu; Mu, Hong-Na; Li, Chong; Chen, Yuan-Yuan; Wang, Chuan-She; Han, Jing-Yan

    2017-02-02

    Dysfunction of energy metabolism is involved in inflammatory bowel disease (IBD). This study was designed to investigate the potential of astragaloside IV (ASIV), an active ingredient of Radix Astragalus, to ameliorate colonic mucosal injury, with focusing on the implication of energy restoration in the underlying mechanism. Experimental colitis model was established in rats by injecting 2,4,6-trinitrobenzene sulfonic acid (TNBS) through anus. After 24 hours, ASIV was administrated once daily by gavage for 6 days. On day 1 and day 7, colon tissue was collected for macroscopic and histological examination, ELISA, Western blot and immunohistochemical analysis. TNBS impaired colonic mucosa with an injured epithelial architecture, increased inflammatory cell infiltration, and decreased colonic blood flow. Lgr5 positive cell number in crypt and β-catenin nuclear translocation were down-regulated by TNBS treatment. TNBS induced epithelial F-actin disruption and junctional protein degradation. Furthermore, adenosine triphosphate (ATP) content and ATP synthase subunit β expression in the colon tissue were significantly decreased after TNBS stimulation. All of the aforementioned alterations were relieved by ASIV post-treatment. The present study revealed that ASIV promoted mucosal healing process in TNBS-induced colitis, which was most likely attributed to regulating energy metabolism.

  5. Astragaloside IV ameliorates 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis implicating regulation of energy metabolism

    PubMed Central

    Jiang, Xu-Guang; Sun, Kai; Liu, Yu-Ying; Yan, Li; Wang, Ming-Xia; Fan, Jing-Yu; Mu, Hong-Na; Li, Chong; Chen, Yuan-Yuan; Wang, Chuan-She; Han, Jing-Yan

    2017-01-01

    Dysfunction of energy metabolism is involved in inflammatory bowel disease (IBD). This study was designed to investigate the potential of astragaloside IV (ASIV), an active ingredient of Radix Astragalus, to ameliorate colonic mucosal injury, with focusing on the implication of energy restoration in the underlying mechanism. Experimental colitis model was established in rats by injecting 2,4,6-trinitrobenzene sulfonic acid (TNBS) through anus. After 24 hours, ASIV was administrated once daily by gavage for 6 days. On day 1 and day 7, colon tissue was collected for macroscopic and histological examination, ELISA, Western blot and immunohistochemical analysis. TNBS impaired colonic mucosa with an injured epithelial architecture, increased inflammatory cell infiltration, and decreased colonic blood flow. Lgr5 positive cell number in crypt and β-catenin nuclear translocation were down-regulated by TNBS treatment. TNBS induced epithelial F-actin disruption and junctional protein degradation. Furthermore, adenosine triphosphate (ATP) content and ATP synthase subunit β expression in the colon tissue were significantly decreased after TNBS stimulation. All of the aforementioned alterations were relieved by ASIV post-treatment. The present study revealed that ASIV promoted mucosal healing process in TNBS-induced colitis, which was most likely attributed to regulating energy metabolism. PMID:28150820

  6. CD4+ T cell responses in Balb/c mice with food allergy induced by trinitrobenzene sulfonic acid and ovalbumin.

    PubMed

    Sun, Chen-Yi; Bai, Jie; Hu, Tian-Yong; Cheng, Bao-Hui; Ma, Li; Fan, Xiao-Qin; Yang, Ping-Chang; Zheng, Peng-Yuan; Liu, Zhi-Qiang

    2016-06-01

    The rapid increase in atopic diseases is potentially linked to increased hapten exposure, however, the role of haptens in the pathogenesis of food allergy remains unknown. Further studies are required to elucidate the cluster of differentiation 4 positive (CD4+) T cell response to food allergy induced by haptens. Dendritic cells were primed by trinitrobenzene sulfonic acid (TNBS) as a hapten or ovalbumin (OVA) as a model antigen, in a cell culture model. BALB/c mice were sensitized using TNBS and/or OVA. Intestinal Th1/Th2 cell and ovalbumin specific CD4+ T cells proliferation, intestinal cytokines (interleukin‑4 and interferon‑γ) in CD4+ T cells were evaluated. TNBS increased the expression of T cell immunoglobulin and mucin domain‑4 and tumor necrosis factor ligand superfamily member 4 in dendritic cells. Skewed Th2 cell polarization, extensive expression of interleukin‑4, reduced expression of interferon‑γ and forkhead box protein P3 were elicited following concomitant exposure to TNBS and OVA, with reduced regulatory T cells in the mouse intestinal mucosa, whereas a Th1 response was detected when challenged by TNBS or OVA alone. This data suggests that TNBS, as a hapten, combined with food antigens may lead to a Th2 cell response in the intestinal mucosa.

  7. Anti-inflammatory intestinal activity of Combretum duarteanum Cambess. in trinitrobenzene sulfonic acid colitis model

    PubMed Central

    de Morais Lima, Gedson Rodrigues; Machado, Flavia Danniele Frota; Périco, Larissa Lucena; de Faria, Felipe Meira; Luiz-Ferreira, Anderson; Souza Brito, Alba Regina Monteiro; Pellizzon, Cláudia Helena; Hiruma-Lima, Clélia Akiko; Tavares, Josean Fechine; Barbosa Filho, José Maria; Batista, Leônia Maria

    2017-01-01

    AIM To evaluate the anti-inflammatory intestinal effect of the ethanolic extract (EtOHE) and hexane phase (HexP) obtained from the leaves of Combretum duarteanum (Cd). METHODS Inflammatory bowel disease was induced using trinitrobenzenesulfonic acid in acute and relapsed ulcerative colitis in rat models. Damage scores, and biochemical, histological and immunohistochemical parameters were evaluated. RESULTS Both Cd-EtOHE and Cd-HexP caused significant reductions in macroscopic lesion scores and ulcerative lesion areas. The vegetable samples inhibited myeloperoxidase increase, as well as pro-inflammatory cytokines TNF-α and IL-1β. Anti-inflammatory cytokine IL-10 also increased in animals treated with the tested plant samples. The anti-inflammatory intestinal effect is related to decreased expression of cyclooxygenase-2, proliferating cell nuclear antigen, and an increase in superoxide dismutase. CONCLUSION The data indicate anti-inflammatory intestinal activity. The effects may also involve participation of the antioxidant system and principal cytokines relating to inflammatory bowel disease. PMID:28293082

  8. Palladium-Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite.

    PubMed

    Shavnya, Andre; Hesp, Kevin D; Mascitti, Vincent; Smith, Aaron C

    2015-11-09

    A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, potassium metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis.

  9. An Evaluation of a Teat Dip with Dodecyl Benzene Sulfonic Acid in Preventing Bovine Mammary Gland Infection from Experimental Exposure to Streptococcus agalactiae and Staphylococcus aureus

    PubMed Central

    Barnum, D. A.; Johnson, R. E.; Brooks, B. W.

    1982-01-01

    The effectiveness of a teat dip with dodecyl benzene sulfonic acid (1.94%) for the prevention of intramammary infections was determined in cows experimentally challenged with Streptococcus agalactiae and Staphylococcus aureus. The infection rates with Streptococcus agalactiae and Staphylococcus aureus were 62.5% and 75% in undipped quarters, 12.5% and 21.5% in dipped quarters with a reduction rate of 80% and 71% respectively. The significance of some findings in relation to mastitis control are discussed. PMID:17422110

  10. The coordination structure of the extracted nickel(ii) complex with a synergistic mixture containing dinonylnaphthalene sulfonic acid and 2-ethylhexyl 4-pyridinecarboxylate ester.

    PubMed

    Li, Jiyuan; Hu, Huiping; Zhu, Shan; Hu, Fang; Wang, Yongxi

    2017-01-24

    In this paper, a synergist complex of Ni(ii) with naphthalene-2-sulfonic acid (HNS) and n-hexyl 4-pyridinecarboxylate ester (L(I)), which are corresponding short chain analogues of active synergistic extractants dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexyl 4-pyridinecarboxylate ester (4PC, L(II)), was prepared and characterized by Nuclear Magnetic Resonance ((1)H-NMR), elemental analyses, Fourier Transform Infrared Spectroscopy (FT-IR) and Electrospray Ionization Mass Spectrometry (ESI-MS) spectroscopic studies. Single crystals of the nickel synergist complex have been grown from a methanol/water (10/1) solution and analyzed by single crystal X-ray diffraction. The crystal structure of the nickel synergist complex shows that Ni(ii) is coordinated by four water molecules and two monodentate L(I) ligands and there is no direct interaction of the Ni(ii) with sulfonic oxygen atoms of naphthalene-2-sulfonic acid anions, while hydrogen-bonded interactions of the coordinated water molecules with sulfonic oxygen atoms of naphthalene-2-sulphate anions were observed. In addition, in order to provide parallels to solvent extraction, the extracted Ni(ii) complex with HDNNS and 4PC is also prepared and studied using FT-IR and ESI-MS technology. Compared with their corresponding free ligand, similar shifts assigned to the stretching vibration of the pyridine ring and S[double bond, length as m-dash]O in both the nickel synergist complex and the extracted Ni(ii) complex suggest that in the non-polar organic phase, Ni(ii) is also coordinated by L(II) ligands, while the sulfonic oxygen atoms of dinonylnaphthalene sulfonate anions not directly bonded to Ni(ii) form hydrogen bonds with water molecules (coordinated with Ni(ii) or/and solubilized in the non-polar organic phase). For the ESI-MS spectrum of the extracted Ni(ii) complex in non-polar organic phase, there exists a peak at m/z values of 1058.76, which indicates that the extracted Ni(ii) complex in the non

  11. A new sulfonic acid derivative, (Z)-4-methylundeca-1,9-diene-6-sulfonic acid, isolated from the cold water sea urchin inhibits inflammatory responses through JNK/p38 MAPK and NF-κB inactivation in RAW 264.7.

    PubMed

    Lee, Dong-Sung; Cui, Xiang; Ko, Wonmin; Kim, Kyoung-Su; Kim, Il Chan; Yim, Joung Han; An, Ren-Bo; Kim, Youn-Chul; Oh, Hyuncheol

    2014-08-01

    In this study, we isolated a new sulfonic acid derivative, (Z)-4-methylundeca-1,9-diene-6-sulfonic acid (1), from the sea urchin collected from the Sea of Okhotsk. We established the structure of this new compound by analysis of NMR and HRMS data, along with comparison of the data with those of the related compounds reported in the literature. In addition, we investigated its anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages. Compound 1 inhibited the production of NO, iNOS, PGE2, and COX-2, and it also suppressed the production of pro-inflammatory cytokines, such as TNF-α and IL-1β. It inhibited the translocation of the NF-κB subunit p65 into the nucleus by interrupting the phosphorylation and degradation of IκB-α. In addition, compound 1 significantly decreased the phosphorylation of JNK and p38 in LPS-stimulated RAW264.7 macrophages, suggesting that suppression of the inflammation process by compound 1 was mediated through the MAPK pathway. Taken together, this study showed that the anti-inflammatory effects of a new sulfonic acid derivative, (Z)-4-methylundeca-1,9-diene-6-sulfonic acid were mediated through the inhibition of NF-κB and JNK/p38 MAPK signaling pathways.

  12. Leads for development of new naphthalenesulfonate derivatives with enhanced antiangiogenic activity: crystal structure of acidic fibroblast growth factor in complex with 5-amino-2-naphthalene sulfonate.

    PubMed

    Fernández-Tornero, Carlos; Lozano, Rosa M; Redondo-Horcajo, Mariano; Gómez, Ana M; López, José C; Quesada, Ernesto; Uriel, Clara; Valverde, Serafín; Cuevas, Pedro; Romero, Antonio; Giménez-Gallego, Guillermo

    2003-06-13

    Inhibition of angiogenesis-promoting factors such as fibroblast growth factors is considered to be a potential procedure for inhibiting solid tumor growth. Although several peptide-based inhibitors are currently under study, the development of antiangiogenic compounds of small molecular size is a pharmacological goal of considerable interest. We have already shown that certain naphthalene sulfonates constitute minimal functional substitutes of the antiangiogenic compounds of the suramin and suradista family. Using those data as a lead, we have carried out a rational search for new angiogenesis inhibitors that could provide new pharmacological insights for the development of antiangiogenic treatments. The results of the study strongly underline the relevance of the stereochemistry for an efficient inhibition of acidic fibroblast growth factor mitogenic activity by the naphthalene sulfonate family and allow us to formulate rules to aid in searching for new inhibitors and pharmaceutical developments. To provide further leads for such developments and acquire a detailed insight into the basis of the inhibitory activity of the naphthalene sulfonate derivatives, we solved the three-dimensional structure of acidic fibroblast growth factor complexed to 5-amino-2-naphthalenesulfonate, the most pharmacologically promising of the identified inhibitors. The structure shows that binding of this compound would hamper the interaction of acidic fibroblast growth factor with the different components of the cell membrane mitogenesis-triggering complex.

  13. p-Sulfonic Acid Calix[4]arene as an Efficient Catalyst for One-Pot Synthesis of Pharmaceutically Significant Coumarin Derivatives under Solvent-Free Condition

    PubMed Central

    Tashakkorian, Hamed; Lakouraj, Moslem Mansour; Rouhi, Mona

    2015-01-01

    One-pot and efficient protocol for preparation of some potent pharmaceutically valuable coumarin derivatives under solvent-free condition via direct coupling using biologically nontoxic organocatalyst, calix[4]arene tetrasulfonic acid (CSA), was introduced. Calix[4]arene sulfonic acid has been incorporated lately as a magnificent and recyclable organocatalyst for the synthesis of some organic compounds. Nontoxicity, solvent-free conditions, good-to-excellent yields for pharmaceutically significant structures, and especially ease of catalyst recovery make this procedure valuable and environmentally benign. PMID:26798517

  14. Simple introduction of sulfonic acid group onto polyethylene by radiation-induced cografting of sodium styrenesulfonate with hydrophilic monomers. [electron beam

    SciTech Connect

    Tsuneda, Satoshi; Saito, Kyoichi; Furusaki, Shintaro . Dept. of Chemical Engineering); Sugo, Takanobu; Makuuchi, Keizo . Takasaki Radiation Chemistry Research Establishment)

    1993-07-01

    The sulfonic acid (SO[sub 3]H) group was readily introduced into a polyethylene (PE) membrane by radiation-induced cografting of sodium styrenesulfonate (SSS) with hydrophilic monomers such as acrylic acid (AAc) and hydroxyethyl methacrylate (HEMA). The density of SSS grafted onto the PE membrane was determined as a function of molar ratio of hydrophilic monomer to SSS in the monomer mixture. Immersion of the electron-beam-irradiated PE membrane into the mixture of SSS and HEMA for 5 h at 323 K provided to the SO[sub 3]H density of 2.5 mol/kg of the H-type product.

  15. Ameliorating effects of short-chain inulin-like fructans on the healing stage of trinitrobenzene sulfonic acid-induced colitis in rats.

    PubMed

    Hino, Shingo; Ito, Hiroyuki; Bito, Hiroyuki; Kawagishi, Hirokazu; Morita, Tatsuya

    2011-01-01

    We evaluated the ameliorating effects of short-chain inulin-like fructans (SIF) with different degrees of polymerization (DP) on the healing stage of trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. The rats were assigned to 3 groups 10 d after the colitis induction, and fed for 24 d on a control diet or diet including 60 g of DP4 or DP8/kg. The fecal myeloperoxidase (MPO) activity and IgA concentration were monitored every 7 d. The colonic MPO activities and cecal concentrations of organic acids, lactobacilli, bifidobacteria, mucin and IgA were measured at the end of the study. DP4, but not DP8, significantly reduced the colonic inflammation accompanied by higher cecal concentrations of short-chain fatty acids, propionate in particular, and lactic acid-producing bacteria. DP4 therefore accelerated the healing process of TNBS-induced colitis, even when the treatment was initiated after inducing colitis.

  16. An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-immobilized electrode for the simultaneous detection of dopamine and uric acid in the presence of ascorbic acid.

    PubMed

    Chih, Yi-Kai; Yang, Ming-Chang

    2013-06-01

    An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)-immobilized carbon nanotube (CNT) electrode was used to simultaneously detect dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) with differential pulse voltammetry. When ABTS was immobilized onto the CNT electrode in the presence of DA, UA and 100 μM AA, the sensitivity to DA increased from 0.600 (±0.013) to 1.334 (±0.010) μA/μM in the concentration ranges of 0.90-10 μM and 1.87-20 μM, respectively, and the sensitivity to UA increased from 0.030 (±0.005) to 0.078 (±0.006) μA/μM in the concentration ranges of 2.16-240 μM and 3.07-400 μM, respectively. These findings demonstrate that the ABTS-immobilized CNT electrode attained a higher sensitivity to UA and also a wider linear range of concentrations.

  17. Identification of Novel Perfluoroalkyl Ether Carboxylic Acids (PFECAs) and Sulfonic Acids (PFESAs) in Natural Waters Using Accurate Mass Time-of-Flight Mass Spectrometry (TOFMS).

    PubMed

    Strynar, Mark; Dagnino, Sonia; McMahen, Rebecca; Liang, Shuang; Lindstrom, Andrew; Andersen, Erik; McMillan, Larry; Thurman, Michael; Ferrer, Imma; Ball, Carol

    2015-10-06

    Recent scientific scrutiny and concerns over exposure, toxicity, and risk have led to international regulatory efforts resulting in the reduction or elimination of certain perfluorinated compounds from various products and waste streams. Some manufacturers have started producing shorter chain per- and polyfluorinated compounds to try to reduce the potential for bioaccumulation in humans and wildlife. Some of these new compounds contain central ether oxygens or other minor modifications of traditional perfluorinated structures. At present, there has been very limited information published on these "replacement chemistries" in the peer-reviewed literature. In this study we used a time-of-flight mass spectrometry detector (LC-ESI-TOFMS) to identify fluorinated compounds in natural waters collected from locations with historical perfluorinated compound contamination. Our workflow for discovery of chemicals included sequential sampling of surface water for identification of potential sources, nontargeted TOFMS analysis, molecular feature extraction (MFE) of samples, and evaluation of features unique to the sample with source inputs. Specifically, compounds were tentatively identified by (1) accurate mass determination of parent and/or related adducts and fragments from in-source collision-induced dissociation (CID), (2) in-depth evaluation of in-source adducts formed during analysis, and (3) confirmation with authentic standards when available. We observed groups of compounds in homologous series that differed by multiples of CF2 (m/z 49.9968) or CF2O (m/z 65.9917). Compounds in each series were chromatographically separated and had comparable fragments and adducts produced during analysis. We detected 12 novel perfluoroalkyl ether carboxylic and sulfonic acids in surface water in North Carolina, USA using this approach. A key piece of evidence was the discovery of accurate mass in-source n-mer formation (H(+) and Na(+)) differing by m/z 21.9819, corresponding to the

  18. A novel PPARα agonist propane-2-sulfonic acid octadec-9-enyl-amide inhibits inflammation in THP-1 cells.

    PubMed

    Zhao, Yun; Yan, Lu; Luo, Xiu-Mei; Peng, Lu; Guo, Han; Jing, Zuo; Yang, Li-Chao; Hu, Rong; Wang, Xuan; Huang, Xue-Feng; Wang, Yi-Qing; Jin, Xin

    2016-10-05

    Our group synthesized propane-2-sulfonic acid octadec-9-enyl-amide (N15), a novel peroxisome proliferator activated receptor alpha (PPARα) agonist. Because PPARα activation is associated with inflammation control, we hypothesize that N15 may have anti-inflammatory effects. We investigated the effect of N15 on the regulation of inflammation in THP-1 cells stimulated with lipopolysaccharide (LPS). In particular, we assessed the production of chemokines, adhesion molecules and proinflammatory cytokines, three important types of cytokines that are released from monocytes and are involved in the development of atherosclerosis. The results showed that N15 remarkably reduced the mRNA expression of chemokines, such as monocyte chemotactic protein 1 (MCP-1 or CCL2), interleukin-8 (IL-8) and interferon-inducible protein-10 (IP-10 or CXCL10), and proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). N15 also decreased the protein expression of vascular cell adhesion molecule (VCAM) and matrix metalloproteinase (MMP) 2 and 9. The reduction in the expression of cytokine mRNAs observed following N15 treatment was abrogated in THP-1 cells treated with PPARα siRNA, indicating that the anti-inflammatory effects of N15 are dependent on PPARα activation. Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) inhibition, which are dependent on PPARα activation, were also involved in the mechanism underlying the anti-inflammatory effects of N15. In conclusion, the novel PPARα agonist, N15, exerts notable anti-inflammatory effects, which are mediated via PPARα activation and TLR4/NF-κB and STAT3 inhibition, in LPS-stimulated THP-1 cells. In our study, N15 exhibits promise for the treatment of atherosclerosis.

  19. The enhancement of fluorescence quantum yields of anilino naphthalene sulfonic acids by inclusion of various cyclodextrins and cucurbit[7]uril.

    PubMed

    Sueishi, Yoshimi; Fujita, Tomonori; Nakatani, Shinichiro; Inazumi, Naoya; Osawa, Yoshihiro

    2013-10-01

    The association constants (K) for the inclusion complexation of four kinds of cyclodextrins (CDs (β- and γ-), 2,6-di-O-methylated β-CD, and 2,3,6-tri-O-methylated β-CD) and cucurbit[7]uril (CB[7]) with 1,8- and 2,6-anilinonaphthalene sulfonic acids (ANSs) were determined from fluorescence spectra enhanced by inclusion. Various CDs and CB[7] form stable 1:1 inclusion complexes with 1,8- and 2,6-ANSs: K=80-11700 M(-1) for 2,6-ANS and 50-195 M(-1) for 1,8-ANS. The high stability of the inclusion complexes of 2,6-ANS with CB[7] and 2,6-di-O-methylated β-CD is shown. Further, we determined the fluorescence quantum yields (Φ values) for the inclusion complexes of ANSs by using a fluorescence spectrophotometer equipped with a half-moon unit. The Φ values of 1,8- and 2,6-ANSs were largely enhanced by the inclusion of methylated β-CDs and did not correlate with the degree of stability (K) of the inclusion complexes. We characterized the structures of the inclusion complexes by 2D ROESY-NMR measurements. In addition, the microenvironmental polarity inside the hydrophobic CD and CB[7] cavities was evaluated using the fluorescence probe 2,6-ANS. Based on the emission mechanism and the aspect of inclusion in a hydrophobic cavity, we have suggested that the microenvironmental polarity and viscosity for the excited state of ANS plays an important role for the Φ values of inclusion complexes.

  20. Protective effects of Aegle marmelos fruit pulp on 2,4,6-trinitrobenzene sulfonic acid-induced experimental colitis

    PubMed Central

    Ghatule, Rohit R.; Gautam, Manish K.; Goel, Shalini; Singh, Amit; Joshi, Vinod K.; Goel, Raj K.

    2014-01-01

    Background: Aegle marmelos (AM) fruit has been advocated in indigenous system of medicine for the treatment of various gastrointestinal disorders, fever, asthma, inflammations, febrile delirium, acute bronchitis, snakebite, epilepsy, leprosy, myalgia, smallpox, leucoderma, mental illnesses, sores, swelling, thirst, thyroid disorders, tumours and upper respiratory tract infections. Objective: The objective of this study was to study the curative effect of 50% ethanol extract of dried fruit pulp of AM (AME) against 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis. Materials and Methods: AME (200 mg/kg) was administered orally, once daily for 14 days after TNBS-induced colitis. Rats were given intracolonic normal saline or TNBS alone or TNBS plus oral AME. AME was studied for its in vitro antibacterial activity against Gram-negative intestinal bacteria and on TNBS-induced changes in colonic damage, weight and adhesions (macroscopic and microscopic), diarrhea, body weight and colonic levels of free radicals (nitric oxide and lipid peroxidation), antioxidants (superoxide dismutase, catalase and reduced glutathione) and pro-inflammatory marker (myeloperoxidase [MPO]) in rats. Results: AME showed antibacterial activity against intestinal pathogens and decreased colonic mucosal damage and inflammation, diarrhea, colonic free radicals and MPO and enhanced body weight and colonic antioxidants level affected by TNBS. The effects of AME on the above parameters were comparable with sulfasalazine, a known colitis protective drug (100 mg/kg, oral). Conclusion: AME shows curative effects against TNBS-induced colitis by its antibacterial activity and promoting colonic antioxidants and reducing free radicals and MPO-induced colonic damage. PMID:24914296

  1. Experimental study of the removal of copper ions using hydrogels of xanthan, 2-acrylamido-2-methyl-1-propane sulfonic acid, montmorillonite: Kinetic and equilibrium study.

    PubMed

    Aflaki Jalali, Marzieh; Dadvand Koohi, Ahmad; Sheykhan, Mehdi

    2016-05-20

    In this paper, removal of copper ions from aqueous solution using novel xanthan gum (XG) hydrogel, xanthan gum-graft-2-acrylamido-2-methyl-1-propane sulfonic acid (XG-g-P(AMPS)) hydrogel and xanthan gum-graft-2-acrylamido-2-methyl-1-propane sulfonic acid/montmorillonite (XG-g-P(AMPS)/MMT) hydrogel composite were studied. The structure and morphologies of the xanthan-based hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Adsorbents comprised a porous crosslink structure with side chains that carried carboxyl, hydroxyl and sulfonate. Maximum adsorption was observed in the pH=5.2, initial concentrations of Cu(2+)=321.8 mg/L, Temperature=45 °C, contact time=5 h with 0.2 g/50 mL of the hydrogels. Adsorption process was found to follow Langmuir isotherm model with maximum adsorption capacity of 24.57, 39.06 and 29.49 mg/g for the XG, XG-g-P(AMPS) and XG-g-P(AMPS)/MMT, respectively. Adsorption kinetics data fitted well with pseudo second order model. The negative ΔG° values and the positive ΔS° confirmed that the adsorption was a spontaneous process. The positive ΔH° values suggested that the adsorption was endothermic in nature.

  2. Separation and fragmentation study of isocoproporphyrin derivatives by UHPLC-ESI-exact mass MS/MS and identification of a new isocoproporphyrin sulfonic acid metabolite.

    PubMed

    Benton, Christopher M; Lim, Chang Kee; Moniz, Caje; Baxter, Sinéad L; Jones, Donald J L

    2014-01-01

    Isocoproporphyrin and its derivatives are commonly used as biomarkers of porphyria cutanea tarda, heavy metal toxicity and hexachlorobenzene (HCB) intoxication in humans and animals. However, most are isobaric with other porphyrins and reference materials are unavailable commercially. The structural characterisation of these porphyrins is important but very little data is available. We report here the separation and characterisation of isocoproporphyrin, deethylisocoproporphyrin, hydroxyisocoproporphyrin and ketoisocoproporphyrin, isolated in the faeces of rats fed with a diet containing HCB, by ultra high performance liquid chromatography-exact mass tandem mass spectrometry (UHPLC-MS/MS). Furthermore, we report the identification and characterisation of a previously unreported porphyrin metabolite, isocoproporphyrin sulfonic acid isolated in the rat faeces. The measured mass-to-charge ratio (m/z) of the precursor ion was m/z 735.2338, corresponding to a molecular formula of C36H39N4O11S with an error of 0.3 ppm from the calculated m/z 735.2336. The MS/MS data was consistent with an isocoproporphyrin sulfonic acid structure, derived from dehydroisocoproporphyrinogen by sulfonation of the vinyl group. The metabolite was present in a greater abundance than other isocoproporphyrin derivatives and may be a more useful biomarker for HCB intoxication.

  3. Degradation and mineralization of organic UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) using UV-254nm/H2O2.

    PubMed

    Abdelraheem, Wael H M; He, Xuexiang; Duan, Xiaodi; Dionysiou, Dionysios D

    2015-01-23

    Various studies have revealed the non-biodegradable and endocrine disrupting properties of sulfonated organic UV absorbers, directing people's attention toward their risks on ecological and human health and hence their removal from water. In this study, UV-254nm/H2O2 advanced oxidation process (AOP) was investigated for degrading a model UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and a structurally similar compound 1H-benzimidazole-2-sulfonic acid (BSA), with a specific focus on their mineralization. At 4.0mM [H2O2]0, a complete removal of 40.0μM parent PBSA and 25% decrease in TOC were achieved with 190min of UV irradiation; SO4(2-) was formed and reached its maximum level while the release of nitrogen as NH4(+) was much lower (around 50%) at 190min. Sulfate removal was strongly enhanced by increasing [H2O2]0 in the range of 0-4.0mM, with slight inhibition in 4.0-12.0mM. Faster and earlier ammonia formation was observed at higher [H2O2]0. The presence of Br(-) slowed down the degradation and mineralization of both compounds while a negligible effect on the degradation was observed in the presence of Cl(-). Our study provides important technical and fundamental results on the HO based degradation and mineralization of SO3H and N-containing UV absorber compounds.

  4. Synthesis, Antibacterial and Antitubercular Activities of Some 5H-Thiazolo[3,2-a]pyrimidin-5-ones and Sulfonic Acid Derivatives.

    PubMed

    Cai, Dong; Zhang, Zhi-Hua; Chen, Yu; Yan, Xin-Jia; Zou, Liang-Jing; Wang, Ya-Xin; Liu, Xue-Qi

    2015-09-10

    A series of 5H-thiazolo[3,2-a]pyrimidin-5-ones were synthesized by the cyclization reactions of S-alkylated derivatives in concentrated H₂SO₄. Upon treatment of S-alkylated derivatives at different temperatures, intramolecular cyclization to 7-(substituted phenylamino)-5H-thiazolo[3,2-a]pyrimidin-5-ones or sulfonation of cyclized products to sulfonic acid derivatives occurred. The structures of the target compounds were confirmed by IR, ¹H-NMR, (13)C-NMR and HRMS studies. The compounds were evaluated for their preliminary in vitro antibacterial activity against some Gram-positive and Gram-negative bacteria and screened for antitubercular activity against Mycobacterium tuberculosis by the broth dilution assay method. Some compounds showed good antibacterial and antitubercular activities.

  5. Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

    NASA Astrophysics Data System (ADS)

    Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

    2015-01-01

    A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln2(phen)2(SO4)3(H2O)2]n (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)]n (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO4 2 - anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic-inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature.

  6. Nafion-assisted cross-linking of sulfonated poly(arylene ether ketone) bearing carboxylic acid groups and their composite membranes for fuel cells

    NASA Astrophysics Data System (ADS)

    Lin, Haidan; Zhao, Chengji; Na, Hui

    In this study, a new type of cross-linked composite membrane is prepared and considered for its potential applications in direct methanol fuel cell. Nafion and sulfonated poly(arylene ether ketone) bearing carboxylic acid groups (SPAEK-C) are blended and subsequently cross-linked by a Friedel-Craft reaction using the carboxylic acid groups in the SPAEK-C to achieve lower methanol permeability. The perfluoroalkyl sulfonic acid groups of Nafion act as a benign solid catalyst, which assist the cross-linking of SPAEK-C. The physical and chemical characterizations of the cross-linked composite membranes are performed by varying the contents of SPAEK-C. The c-Nafion-15% membrane exhibits appropriate water uptake (10.49-25.22%), low methanol permeability (2.57 × 10 -7 cm 2 s -1), and high proton conductivity (0.179 S cm -1 at 80 °C). DSC and FTIR analyze suggest the cross-linking reaction. These results show that the self-cross-linking of SPAEK-C in the Nafion membrane can effectively reduce methanol permeability while maintaining high proton conductivity.

  7. Proton conductivity and fuel cell property of composite electrolyte consisting of Cs-substituted heteropoly acids and sulfonated poly(ether-ether ketone)

    NASA Astrophysics Data System (ADS)

    Oh, S. Y.; Yoshida, T.; Kawamura, G.; Muto, H.; Sakai, M.; Matsuda, A.

    Inorganic-organic composite electrolytes were fabricated from partially Cs +-substituted heteropoly acids (Cs-HPAs) and sulfonated poly(ether-ether ketone) (SPEEK) for application in fuel cells. Heteropoly acids, such as phosphotungstic acid (H 3PW 12O 40:WPA), and silicotungstic acid (H 4SiW 12O 40:WSiA), were mechanochemically treated with cesium hydrogen sulfate (CsHSO 4) to obtain the form of Cs-HPAs. SPEEK was prepared from PEEK by sulfonation using concentrated sulfuric acid. Water durability and surface structure of HPAs were modified by introducing Cs + into HPAs. Flexible and hot water stable composite electrolytes were obtained, and their electrochemical properties were markedly improved with the addition of Cs-HPAs into the SPEEK matrix. Maximum power densities of 245 and 247 mW cm -2 were obtained for 50WPA·50CsHSO 4 and 50WSiA·50CsHSO 4 in SPEEK (1/5 by weight) composite electrolytes, respectively, from single cell tests at 80 °C and 80 RH%. These results suggest that a three-dimensional proton-conductive path was formed among homogeneously distributed Cs-HPAs particles in the SPEEK matrix. The Cs-HPAs incorporated into the SPEEK matrix increased the number of protonate sites in the electrolyte. These observations imply that the mechanochemically synthesized Cs-HPAs, which consist of hydrogen bondings between Cs-HPAs and -HSO 4 -, dissociated from CsHSO 4, are promising materials as inorganic fillers in inorganic-organic composite.

  8. Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and Schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

    NASA Astrophysics Data System (ADS)

    Boghaei, Davar M.; Gharagozlou, Mehrnaz

    2007-07-01

    A series of new ternary zinc(II) complexes [Zn(L 1-10)(phen)], where phen is 1,10-phenanthroline and H 2L 1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, L-phenylalanine, L-valine, L-alanine, and L-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δ ν ( νas(COO) - νs(COO)) of 191-225 cm -1, indicating a monodentate coordination of the carboxylate group. Spectral data showed that in these ternary complexes the zinc atom is coordinated with the Schiff base ligand acts as a tridentate ONO moiety, coordinating to the metal through its phenolic oxygen, imine nitrogen, and carboxyl oxygen, and also with the neutral planar chelating ligand, 1,10-phenanthroline, coordinating through nitrogens.

  9. Enhanced conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) film by acid treatment for indium tin oxide-free organic solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Chun-Chiao; Huang, Chih-Kuo; Hung, Yu-Chieh; Chang, Mei-Ying

    2016-08-01

    An acid treatment is used in the enhancement of the conductivity of the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin film, which is often used as the anode in organic solar cells. There are three types of acid treatment for PEDOT:PSS thin film: hydrochloric, sulfuric, and phosphoric acid treatments. In this study, we examine and compare these three ways with each other for differences in conductivity. Hydrochloric acid results in the highest conductivity enhancement, from 0.3 to 1109 S/cm. We also discuss the optical transmittance, conductivity, surface roughness, surface morphology, and stability, as well as the factors that can influence device efficiency. The devices are fabricated using an acid-treated PEDOT:PSS thin film as the anode. The highest power conversion efficiency was 1.32%, which is a large improvement over that of the unmodified organic solar cell (0.21%). It is comparable to that obtained when using indium tin oxide (ITO) as an electrode, ca. 1.46%.

  10. Magnetic solid sulfonic acid decorated with hydrophobic regulators: a combinatorial and magnetically separable catalyst for the synthesis of α-aminonitriles.

    PubMed

    Mobaraki, Akbar; Movassagh, Barahman; Karimi, Babak

    2014-07-14

    A three-component, Strecker reaction of a series of aldehydes or ketones, amines, and trimethylsilyl cyanide for the synthesis of α-aminonitriles in the presence of a catalytic amount of a magnetic solid sulfonic acid catalyst, Fe3O4@SiO2@Me&Et-PhSO3H under solvent-free conditions have been investigated. This catalyst, with a combination of hydrophobicity and acidity on the Fe3O4@SiO2 core-shell of the magnetic nanobeads, as well as its water-resistant property, enabled easy mass transfer and catalytic activity in the Strecker reaction. The catalyst was easily separated by an external magnet and the recovered catalyst was reused in 6 successive reaction cycles without any significant loss of activity.

  11. Preparation and characterization of poly(2-acrylamido-2-methylpropane-sulfonic acid)/Chitosan hydrogel using gamma irradiation and its application in wastewater treatment

    NASA Astrophysics Data System (ADS)

    Gad, Y. H.

    2008-09-01

    Radiation grafting of chitosan with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) has been successfully performed. The effect of absorbed dose (kGy) and the chitosan:AMPS ratio on graft hydrogelization was studied. The structure of the prepared hydrogel was confirmed using infrared spectroscopy (IR). Thermal properties were simultaneously studied by thermogravimetric analysis (TGA). The effect of the polymerization variables on the swelling % of the prepared hydrogel was investigated. The highest equilibrium degree of swelling (38.6 g/g) and gel % (94.7%) of the prepared chitosan-AMPS hydrogel was at 40% AMPS and absorbed dose of 10 kGy. The removal of methylene blue, acid red dye, Cd (II) and Cr (III) from composed wastewater was also investigated. The effect of pH, the chitosan:AMPS ratio and the concentration of the pollutant on the adsorption process were studied.

  12. Biocompatibility of polypropylene non-woven fabric membrane via UV-induced graft polymerization of 2-acrylamido-2-methylpropane sulfonic acid

    NASA Astrophysics Data System (ADS)

    Song, Lingjie; Zhao, Jie; Yang, Huawei; Jin, Jing; Li, Xiaomeng; Stagnaro, Paola; Yin, Jinghua

    2011-10-01

    This work described the graft polymerization of a sulfonic acid terminated monomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), onto the surface of polypropylene non-woven (NWF PP) membrane by O 2 plasma pretreatment and UV-induced photografting method. The chemical structure and composition of the modified surfaces were analyzed by FTIR-ATR and XPS, respectively. The wettability was investigated by water contact angle and equilibrium water adsorption. And the biocompatibility of the modified NWF PP membranes was evaluated by protein adsorption and platelet adhesion. It was found that the graft density increased with prolonging UV irradiation time and increasing AMPS concentration; the water contact angles of the membranes decreased from 124° to 26° with the increasing grafting density of poly(AMPS) from 0 to 884.2 μg cm -2, while the equilibrium water adsorption raised from 5 wt% to 75 wt%; the protein absorption was effectively suppressed with the introduction of poly(AMPS) even at the low grafting density (132.4 μg cm -2); the number of platelets adhering to the modified membrane was dramatically reduced when compared with that on its virgin surface. These results indicated that surface modification of NWF PP membrane with AMPS was a facile approach to construct biocompatible surface.

  13. Sulfonic acid-functionalized hybrid organic-inorganic proton exchange membranes synthesized by sol-gel using 3-mercaptopropyl trimethoxysilane (MPTMS)

    NASA Astrophysics Data System (ADS)

    Mosa, J.; Durán, A.; Aparicio, M.

    2015-11-01

    Organic/inorganic hybrid membranes based on (3-glycidoxypropyl) trimethoxysilane (GPTMS) and 3-mercaptopropyl trimethoxysilane (MPTMS) have been prepared by sol-gel method and organic polymerisation, as candidate materials for proton exchange membranes in direct alcohol fuel cell (DMFC) applications. The -SH groups of MPTMS are oxidized to sulfonic acid groups, which are attributed to enhance the proton conductivity of hybrid membranes. FTIR, XPS and contact angle were used to characterize and confirm the hybrid structure and oxidation reaction progress. Membranes characterization also includes ion exchange capacity, water uptake, methanol permeability and proton conductivity to confirm their applicability in fuel cells. All the membranes were homogeneous and thermally and chemically resistant. In particular, the hybrid membranes demonstrated proton conductivities as high as 0.16 S cm-1 at high temperature, while exhibiting a low methanol permeability as compared to Nafion®. These results are associated with proton conducting paths through the silica pseudo-PEO network in which sulfonic acid groups work as proton donor.

  14. Sulfonic acid-functionalized silica-coated magnetic nanoparticles as an efficient reusable catalyst for the synthesis of 1-substituted 1H-tetrazoles under solvent-free conditions.

    PubMed

    Naeimi, Hossein; Mohamadabadi, Samaneh

    2014-09-14

    Regarding green chemistry goals, silica-coated magnetite nanoparticles open up a new avenue to introduce a very useful and efficient system for facilitating catalyst recovery in different organic reactions. Therefore, in this paper the preparation of sulfonic acid-functionalized silica-coated magnetic nanoparticles with core-shell structure (Fe3O4@silica sulfonic acid) is presented by using Fe3O4 spheres as the core and silica sulfonic acid nanoparticles as the shell. The catalyst was characterized by infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, dynamic light scattering, thermogravimetric analysis and vibrating sample magnetometry. Nanocatalyst can be recovered using an external magnet and reused for subsequent reactions 6 times without noticeable deterioration in catalytic activity.

  15. Sulfonic acid resin-catalyzed addition of phenols, carboxylic acids, and water to olefins: Model reactions for catalytic upgrading of bio-oil.

    PubMed

    Zhang, Zhi-Jun; Wang, Qing-Wen; Yang, Xu-Lai; Chatterjee, Sabornie; Pittman, Charles U

    2010-05-01

    Acid-catalyzed 1-octene reactions with phenol and mixtures of phenol with water, acetic acid and 1-butanol were studied as partial bio-oil upgrading models. Bio-oil from fast biomass pyrolysis has poor fuel properties due to the presence of substantial amounts of water, carboxylic acid, phenolic derivatives and other hydroxyl-containing compounds. Additions across olefins offer a route to simultaneously lower water content and acidity while increasing hydrophobicity, stability and heating value. Amberlyst15, Dowex50WX2 and Dowex50WX4 effectively catalyzed phenol O- and C-alkylation from 65 to 120 degrees C, giving high O-alkylation selectivities in the presence of water, acetic acid and 1-butanol. Octanols and dioctyl ethers were formed from water and octyl acetates and phenol acetates from acetic acid. Phenol alkylation slowed in the presence of water. Dowex50WX2 and Dowex50WX4 were more stable in the presence of water than Amberlyst15 and were successfully recycled. Adding 1-butanol to phenol/water/1-octene, gave emulsion-like mixtures which improved phenol conversion and olefin hydration.

  16. Immunotoxicity of perfluorooctanoic acid and perfluorooctane sulfonate and the role of peroxisome proliferator-activated receptor alpha

    EPA Science Inventory

    Peroxisome proliferators, including perfluorooctanoic acid (PFOA), are environmentally widespread and persistent and multiple toxicities have been reported in experimental animals and humans. These compounds trigger biological activity via activation of the alpha isotype of pero...

  17. Penicillanic acid sulfone: an unexpected isotope effect in the interaction of 6 alpha- and 6 beta-monodeuterio and of 6,6-dideuterio derivatives with RTEM beta-lactamase from Escherichia coli.

    PubMed

    Brenner, D G; Knowles, J R

    1981-06-23

    Penicillanic acid sulfone (1) is both a substrate and an inactivator of the RTEM beta-lactamase. About 7000 hydrolytic events occur before enzyme inactivation. The 6,6-dideuterio sulfone shows a 3-fold acceleration of both the hydrolysis reaction and the enzyme inactivation. The kinetic and spectroscopic results are nicely accommodated by a scheme in which a transiently stable intermediate is formed in an isotopically sensitive step. The deuterated material partitions less readily toward this transiently stable intermediate by virtue of a primary isotope effect, and more enzyme is then available for the hydrolysis and inactivation pathways. Use of the stereospecifically monodeuterated sulfones shows that the 6 beta hydrogen is preferentially abstracted in the formation of the transiently stable intermediate and allows a detailed picture of the interaction of the sulfone and the beta-lactamase to be drawn. The crystal structures of both the labeled and unlabeled compounds are reported.

  18. Properties investigation of sulfonated poly(ether ether ketone)/polyacrylonitrile acid-base blend membrane for vanadium redox flow battery application.

    PubMed

    Li, Zhaohua; Dai, Wenjing; Yu, Lihong; Liu, Le; Xi, Jingyu; Qiu, Xinping; Chen, Liquan

    2014-11-12

    Acid-base blend membrane prepared from sulfonated poly(ether ether ketone) (SPEEK) and polyacrylonitrile (PAN) was detailedly evaluated for vanadium redox flow battery (VRFB) application. SPEEK/PAN blend membrane exhibited dense and homogeneous cross-section morphology as scanning electron microscopy and energy-dispersive X-ray spectroscopy images show. The acid-base interaction of ionic cross-linking and hydrogen bonding between SPEEK and PAN could effectively reduce water uptake, swelling ratio, and vanadium ion permeability, and improve the performance and stability of blend membrane. Because of the good balance of proton conductivity and vanadium ion permeability, blend membrane with 20 wt % PAN (S/PAN-20%) showed higher Coulombic efficiency (96.2% vs 91.1%) and energy efficiency (83.5% vs 78.4%) than Nafion 117 membrane at current density of 80 mA cm(-2) when they were used in VRFB single cell. Besides, S/PAN-20% membrane kept a stable performance during 150 cycles at current density of 80 mA cm(-2) in the cycle life test. Hence the SPEEK/PAN acid-base blend membrane could be used as promising candidate for VRFB application.

  19. Preparation of Poly[Styrene(ST)-co-Allyloxy-2-Hydroxypropane Sulfonic Acid Sodium Salt(COPS-I)] Colloidal Crystalline Photonic Crystals.

    PubMed

    Choo, Hun Seung; Lee, Ki Chang

    2015-10-01

    Colloidal crystalline photonic crystals using highly monodisperse poly[Styrene(ST)-co-Allyloxy-2-hydroxypropane sulfonic acid sodium salt(COPS-I)] microspheres were prepared to study their optical properties under visible light. For this purpose, a series of surfactant-free emulsion copolymerizations was carried out at various reaction conditions such as the changes of ST/COPS-I ratio, polymerization temperature, KPS initiator and DVB crosslinker concentration. All the latices showed highly uniform spherical particles in the size range of 165-550 nm and the respective opaline structural colors from their colloidal photonic crystals. It is found that the changes in such polymerization factors greatly affect the number of particles and particle diameter, polymerization rate, molecular weight, zeta-potential, and refractive indices.

  20. A sequential injection method for the fluorimetric determination of aluminum in drinking water using 8-hydroxy-7-(4-sulfo-1-naphthylazo)-5-quinoline sulfonic acid.

    PubMed

    Al-Kindy, Salma M Z; Al-Ghamari, Salwa S; Suliman, Fakhr Eldin O

    2007-12-31

    A robust and simple sequential injection (SI) method for the assay of aluminum ions in drinking water is described. The method is based on the complex formation between aluminum and 8-hydroxy-7-(4-sulfo-1-naphthylazo)-5-quinoline sulfonic acid (HSNQ). The fluorescence of the complex is monitored at an emission wavelength of 492 nm with excitation at 357 nm. The HSNQ concentration, aspirated reagent and sample volumes were optimized simultaneously using 3(3) full factorial design. The optimum operating conditions are aspirated sample and reagent volumes of 90 and 70 microL, respectively, and HSNQ concentration of 20 microM. With these conditions linear calibration curves were obtained from 100 to 800 ppb. The detection limit was 4 ppb. The maximum relative standard deviation of the method was 1.43% (n=5). The method was successfully applied for the determination of aluminum in drinking water samples.

  1. β-Cyclodextrin-Propyl Sulfonic Acid Catalysed One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles as Local Anesthetic Agents.

    PubMed

    Ran, Yan; Li, Ming; Zhang, Zong-Ze

    2015-11-12

    Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. The local anesthetic effect of these derivatives was assessed in comparison to lidocaine as a standard using a rabbit corneal and mouse tail anesthesia model. The three most potent promising compounds were subjected to a rat sciatic nerve block assay where they showed considerable local anesthetic activity, along with minimal toxicity. Among the tested analogues, 4-(1-benzyl-4,5-diphenyl-1H-imidazol-2-yl)-N,N-dimethylaniline (5g) was identified as most potent analogue with minimal toxicity. It was further characterized by a more favourable therapeutic index than the standard.

  2. Self-assembled multilayer films containing 1,8,15,22-tetrakis (8-quinolineoxy-5-sulfonic acid)-phthalocyanine copper: Preparation, and third order nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    He, Chunying; Fan, Jingze; Li, Zhongguo; Gao, Yachen; Chen, Zhimin; Song, Yinglin; Wu, Yiqun; wang, Bin

    2014-02-01

    Composite film with alternating layers containing anionic 1,8,15,22-tetrakis (8-quinolineoxy-5-sulfonic acid)-phthalocyanine copper and cationic polydiallydimethylammonium chloride was fabricated by electrostatic self-assembled layer-by-layer (LBL) technique. The microstructure of the film was characterized by a series of techniques. The third-order nonlinear optical properties of the film were measured using 4f coherent imaging system with phase object (NIT-PO) with laser duration of 20 ps at the wavelength of 532 nm. The film exhibited excellent nonlinear absorption and self-focusing effect. The second-order molecular hyperpolarizability γ value of the film reaches as high as 1.54 × 10-29 esu.

  3. Perfluoroalkyl sulfonates and carboxylic acids in liver, muscle and adipose tissues of black-footed albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean.

    PubMed

    Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J; Li, Qing X

    2015-11-01

    The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g(-1) wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g(-1) ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties.

  4. Perfluoroalkyl Sulfonates and Carboxylic Acids in Liver, Muscle and Adipose Tissues of Black-Footed Albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean

    PubMed Central

    Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J.; Li, Qing X.

    2015-01-01

    The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g-1 wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g-1 ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and C16 PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties. PMID:26037817

  5. Polyacrylamido-2-methyl-1-propane sulfonic acid-grafted-natural rubber as bio-adsorbent for heavy metal removal from aqueous standard solution and industrial wastewater.

    PubMed

    Phetphaisit, Chor Wayakron; Yuanyang, Siriwan; Chaiyasith, Wipharat Chuachuad

    2016-01-15

    Bio-adsorbent modified natural rubber (modified NR) was prepared, by placing the sulfonic acid functional group on the isoprene chain. This modification was carried out with the aim to prepare material capable to remove heavy metals from aqueous solution. The structures of modified NR materials were characterized by FT-IR and NMR spectroscopies. Thermal gravimetric analysis of modified NR showed that the initial degradation temperature of rubber decreases with increasing amount of polyacrylamido-2-methyl-1-propane sulfonic acid (PAMPS) in the structure. In addition, water uptake of the rubber based materials was studied as a function of time and content of PAMPS. The influence of the amount of PAMPS grafted onto NR, time, pH, concentration of metal ions, temperature, and regeneration were studied in terms of their influence on the adsorption of heavy metals (Pb(2+), Cd(2+) and Cu(2+)). The adsorption isotherms of Pb(2+) and Cd(2+) were fitted to the Freundlich isotherm model, while Cu(2+) was fitted to the Langmuir isotherm. However, the results from these two isotherms resulted in a similar behavior. The adsorption capacity of the modified NR for the various heavy metals was in the following order: Pb(2+)∼Cd(2+)>Cu(2+). The maximum adsorption capacities of Pb(2+), Cd(2+), and Cu(2+) were 272.7, 267.2, and 89.7 mg/g of modified rubber, respectively. Moreover, the modified natural rubber was used for the removal of metal ions in real samples of industrial effluents where the efficiency and regeneration were also investigated.

  6. Consecutive visible-light photoredox decarboxylative couplings of adipic acid active esters with alkynyl sulfones leading to cyclic compounds.

    PubMed

    Li, Jingjing; Tian, Hua; Jiang, Min; Yang, Haijun; Zhao, Yufen; Fu, Hua

    2016-07-07

    Novel and efficient consecutive photoredox decarboxylative couplings of adipic acid active esters (bis(1,3-dioxoisoindolin-2-yl)-substituted hexanedioates) with substituted 1-(2-arylethynylsulfonyl)benzenes have been developed under visible-light photocatalysis. The successive photoredox decarboxylative C-C bond formation at room temperature afforded the corresponding cyclic compounds in good yields with tolerance of some functional groups.

  7. Comparison of the toxicokinetic behavior of perfluorohexanoic acid (PFHxA) and nonafluorobutane-1-sulfonic acid (PFBS) in cynomolgus monkeys and rats.

    PubMed

    Chengelis, Christopher P; Kirkpatrick, Jeannie B; Myers, Nichole R; Shinohara, Motoki; Stetson, Philip L; Sved, Daniel W

    2009-06-01

    The toxicokinetics of perfluorohexanoic acid (PFHxA) and nonafluoro-1-butanesulfonic acid (PFBS) were evaluated in Sprague-Dawley rats and cynomolgus monkeys. Systemic exposure to PFHxA was lower than for PFBS following single equivalent intravenous or oral (rat only) doses. Serum clearance was more rapid for PFHxA than for PFBS. In rats, exposure to PFHxA and PFBS was up to 8-fold (intravenous) and 4-fold (oral) higher for males than females and serum clearance of PFHxA and PFBS was more rapid in females than males; however, there was no appreciable difference in the extent or rate of urinary elimination between compounds or genders. There were no apparent differences between genders in the serum half-life for PFHxA following 26 days of repeated oral dosing in rats; exposure decreased upon repeated dosing.

  8. Electrocatalytic activities of cathode electrodes for water electrolysis using tetra-alkyl-ammonium-sulfonic acid ionic liquid as electrolyte

    NASA Astrophysics Data System (ADS)

    Fiegenbaum, Fernanda; de Souza, Michèle O.; Becker, Márcia R.; Martini, Emilse M. A.; de Souza, Roberto F.

    2015-04-01

    The hydrogen evolution reaction (HER) performed with platinum (Pt), nickel (Ni), stainless steel 304 (SS) or glassy carbon (GC) cathodes in 0.1 M 3-triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS.BF4) solution is studied using quasi-potentiostatic and impedance spectroscopy techniques. The objective is to compare the catalytic effect on the cathode using different materials to obtain hydrogen by water electrolysis. Furthermore, the catalytic effect of the ionic liquid (IL) on the cathode compared with that of a hydrochloric acid (HCl) solution with same pH value (0.8) is reported. A low activation energy (Ea) of 8.7 kJ mol-1 is found for the glassy carbon cathode. Tafel plots obtained with TEA-PS.BF4 IL suggest the formation of an electroactive layer of IL on the cathode, which may be responsible for the catalytically enhanced performance observed.

  9. Synthesis of Met-enkephalin by solution-phase peptide synthesis methodology utilizing para-toluene sulfonic acid as N-terminal masking of l-methionine amino acid.

    PubMed

    Khan, Riaz A

    2016-12-01

    The Met-enkephalin, Tyr-Gly-Gly-Phe-Met, was synthesized by the solution-phase synthesis (SPS) methodology employing -OBzl group as carboxyls' protection, while the t-Boc groups were employed for the N-terminal α-amines' protection for the majority of the amino acids of the pentapeptide sequence. The l-methionine (l-Met) amino acid was used as PTSA.Met-OBzl obtained from the simultaneous protection of the α-amino, and carboxyl group with para-toluene sulfonic acid (PTSA) and as-OBzl ester, respectively in a C-terminal start of the 2 + 2 + 1 fragments condensation convergent synthetic approach. The protection strategy provided a short, single-step, simultaneous, orthogonal, nearly quantitative, robust, and stable process to carry through the protected l-methionine and l-phenylalanine coupling without any structural deformities during coupling and workups. The structurally confirmed final pentapeptide product was feasibly obtained in good yields through the current approach.

  10. Toxicology of Perfluoroalkyl Acids*

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-12 in length) and an acidic functional moiety (carboxylate or sulfonate). These compounds are chemically stable, have excellent surface-tension reducing properties...

  11. Presence of UV filters in surface water and the effects of phenylbenzimidazole sulfonic acid on rainbow trout (Oncorhynchus mykiss) following a chronic toxicity test.

    PubMed

    Grabicova, Katerina; Fedorova, Ganna; Burkina, Viktoriia; Steinbach, Christoph; Schmidt-Posthaus, Heike; Zlabek, Vladimir; Kocour Kroupova, Hana; Grabic, Roman; Randak, Tomas

    2013-10-01

    UV filters belong to a group of compounds that are used by humans and are present in municipal waste-waters, effluents from sewage treatment plants and surface waters. Current information regarding UV filters and their effects on fish is limited. In this study, the occurrence of three commonly used UV filters - 2-phenylbenzimidazole-5-sulfonic acid (PBSA), 2-hydroxy-4-methoxybenzophenone (benzophenone-3, BP-3) and 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (benzophenone-4, BP-4) - in South Bohemia (Czech Republic) surface waters is presented. PBSA concentrations (up to 13μgL(-1)) were significantly greater than BP-3 or BP-4 concentrations (up to 620 and 390ngL(-1), respectively). On the basis of these results, PBSA was selected for use in a toxicity test utilizing the common model organism rainbow trout (Oncorhynchus mykiss). Fish were exposed to three concentrations of PBSA (1, 10 and 1000µgL(-1)) for 21 and 42 days. The PBSA concentrations in the fish plasma, liver and kidneys were elevated after 21 and 42 days of exposure. PBSA increased activity of certain P450 cytochromes. Exposure to PBSA also changed various biochemical parameters and enzyme activities in the fish plasma. However, no pathological changes were obvious in the liver or gonads.

  12. Effect of propane-2-sulfonic acid octadec-9-enyl-amide on the expression of adhesion molecules in human umbilical vein endothelial cells.

    PubMed

    Chen, Cai-Xia; Yang, Li-Chao; Xu, Xu-Dong; Wei, Xiao; Gai, Ya-Ting; Peng, Lu; Guo, Han; Hao-Zhou; Wang, Yi-Qing; Jin, Xin

    2015-06-05

    Oleoylethanolamide (OEA), an endogenous agonist of PPARα, has been reported to have anti-atherosclerotic properties. However, OEA can be enzymatically hydrolyzed to oleic acid and ethanolamine and, thus, is not expected to be orally active. In the present study, we designed and synthesized an OEA analog, propane-2-sulfonic acid octadec-9-enyl-amide (N15), which is resistant to enzymatic hydrolysis. The purpose of this study was to investigate the effects of N15 on the expression of adhesion molecules in human umbilical vein endothelial cells (HUVECs). The results showed that N15 inhibited TNFα-induced production of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 and the adhesion of monocytes to TNFα-induced HUVECs. Furthermore, the protective effect of N15 on inflammation is dependent upon a PPAR-α/γ-mediated mechanism. In conclusion, N15 protects against TNFα-induced vascular endothelial inflammation. This anti-inflammatory effect of N15 is dependent on PPAR-α/γ dual targets.

  13. Electrochemical sensor based on molecularly imprinted film at polypyrrole-sulfonated graphene/hyaluronic acid-multiwalled carbon nanotubes modified electrode for determination of tryptamine.

    PubMed

    Xing, Xianrong; Liu, Su; Yu, Jinghua; Lian, Wenjing; Huang, Jiadong

    2012-01-15

    An imprinted electrochemical sensor based on polypyrrole-sulfonated graphene (PPy-SG)/hyaluronic acid-multiwalled carbon nanotubes (HA-MWCNTs) for sensitive detection of tryptamine was presented. Molecularly imprinted polymers (MIPs) were synthesized by electropolymerization using tryptamine as the template, and para-aminobenzoic acid (pABA) as the monomer. The surface feature of the modified electrode was characterized by cyclic voltammetry (CV). The proposed sensor was tested by chronoamperometry. Several important parameters controlling the performance of the molecularly imprinted sensor were investigated and optimized. The results showed that the PPy-SG composites films showed improved conductivity and electrochemical performances. HA-MWCNTs bionanocomposites could enhance the current response evidently. The good selectivity of the sensor allowed three discriminations of tryptamine from interferents, which include tyramine, dopamine and tryptophan. Under the optimal conditions, a linear ranging from 9.0×10(-8) mol L(-1) to 7.0×10(-5) mol L(-1) for the detection of tryptamine was observed with the detection limit of 7.4×10(-8) mol L(-1) (S/N=3). This imprinted electrochemical sensor was successfully employed to detect tryptamine in real samples.

  14. Zwitterionic chiral stationary phases based on cinchona and chiral sulfonic acids for the direct stereoselective separation of amino acids and other amphoteric compounds.

    PubMed

    Zhang, Tong; Holder, Emilie; Franco, Pilar; Lindner, Wolfgang

    2014-06-01

    An extensive series of free amino acids and analogs were directly resolved into enantiomers (and stereoisomers where appropriate) by HPLC on zwitterionic chiral stationary phases (Chiralpak ZWIX(+) and Chiralpak ZWIX(-)). The interaction and chiral recognition mechanisms were based on the synergistic double ion-paring process between the analyte and the chiral selectors. The chiral separation and elution order were found to be predictable for primary α-amino acids with apolar aliphatic side chains. A systematic investigation was undertaken to gain an insight into the influence of the structural features on the enantiorecognition. The presence of polar and/or aromatic groups in the analyte structure is believed to tune the double ion-paring equilibrium by the involvement of the secondary interaction forces such as hydrogen bonding, Van der Waals forces and π-π stacking in concert with steric parameters. The ZWIX chiral columns were able to separate enantiomers and stereoisomers of various amphoteric compounds with no need for precolumn derivatization. Column switching between ZWIX(+) and ZWIX(-) is believed to be an instrumental tool to reverse or control the enantiomers elution order, due to the complementarity of the applied chiral selectors.

  15. Crystal structure of 2-benzene­sulfon­amido-3-hy­droxy­propanoic acid

    PubMed Central

    Jabeen, Nabila; Mushtaq, Misbah; Danish, Muhammad; Tahir, Muhammad Nawaz; Raza, Muhammad Asam

    2015-01-01

    In the title compound, C9H11NO5S, the O=S=O plane of the sulfonyl group is twisted at a dihedral angle of 52.54 (16)° with respect to the benzene ring. The dihedral angle between the carb­oxy­lic acid group and the benzene ring is 49.91 (16)°. In the crystal, C—H⋯O, N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into (001) sheets. PMID:26594589

  16. Strong Lewis acid air-stable cationic titanocene perfluoroalkyl(aryl)sulfonate complexes as highly efficient and recyclable catalysts for C-C bond forming reactions.

    PubMed

    Li, Ningbo; Wang, Jinying; Zhang, Xiaohong; Qiu, Renhua; Wang, Xie; Chen, Jinyang; Yin, Shuang-Feng; Xu, Xinhua

    2014-08-14

    A series of strong Lewis acid air-stable titanocene perfluoroalkyl(aryl)sulfonate complexes Cp2Ti(OH2)2(OSO2X)2·THF (X = C8F17, 1·THF; X = C4F9, 2·H2O·THF; X = C6F5, 3) were successfully synthesized by the treatment of Cp2TiCl2 with C8F17SO3Ag, C4F9SO3Ag and C6F5SO3Ag, respectively. In contrast to well-known titanocene bis(triflate), these complexes showed no change in open air over three months. TG-DSC analysis showed that 1·THF, 2·H2O·THF and 3 were thermally stable at 230 °C, 220 °C and 280 °C, respectively. Conductivity measurements showed that these complexes underwent ionic dissociation in CH3CN solution. X-ray analysis results confirmed that 2·H2O·THF and 3 were cationic. ESR spectra showed that the Lewis acidity of 1·THF (1.06 eV) was higher than that of Sc(3+) (1.00 eV) and Y(3+) (0.85 eV). UV/Vis spectra showed a significant red shift due to the strong complex formation between 10-methylacridone and 2·H2O·THF. Fluorescence spectra showed that the Lewis acidity of 2 (λ(em) = 477 nm) was higher than that of Sc(3+) (λ(em) = 474 nm). These complexes showed high catalytic ability in various carbon-carbon bond forming reactions. Moreover, they show good reusability. Compared with 1·THF, 2·H2O·THF and 3 exhibit higher solubility and better catalytic activity, and will find broad applications in organic synthesis.

  17. Degradation of chloroacetanilide herbicides: The prevalence of sulfonic and oxanilic acid metabolites in Iowa groundwaters and surface waters

    USGS Publications Warehouse

    Kalkhoff, S.J.; Kolpin, D.W.; Thurman, E.M.; Ferrer, I.; Barcelo, D.

    1998-01-01

    Water samples were collected from 88 municipal wells throughout Iowa during the summer and were collected monthly at 12 stream sites in eastern Iowa from March to December 1996 to study the occurrence of the sulfonic and oxanilic metabolites of acetochlor, alachlor, and metolachlor. The sulfonic and oxanilic metabolites were present in almost 75% of the groundwater samples and were generally present from 3 to 45 times more frequently than their parent compounds. In groundwater, the median value of the summed concentrations of acetochlor, alachlor, and metolachlor was less than 0.05 μg/L, and the median value of the summed concentrations of the six metabolites was 1.2 μg/L. All surface water samples contained at least one detectable metabolite compound. Individual metabolites were detected from 2 to over 100 times more frequently than the parent compounds. In surface water, the median value of the summed concentrations of the three parent compounds was 0.13 μg/L, and the median value of the summed concentrations of the six metabolites was 6.4 μg/L. These data demonstrate the importance of analyzing both parent compounds and metabolites to more fully understand the environmental fate and transport of herbicides in the hydrologic system.

  18. Preparation of Fe3O4 encapsulated-silica sulfonic acid nanoparticles and study of their in vitro antimicrobial activity.

    PubMed

    Naeimi, Hossein; Nazifi, Zahra Sadat; Amininezhad, Seyedeh Matin

    2015-08-01

    A simple and efficient method for the functionalization of silica-coated Fe3O4 magnetic nanoparticles (Fe3O4@SiO2) using chlorosulfonic acid is described. The prepared compounds were screened for antibacterial activity against Escherichia coli (E. coli ATCC 25922) and Staphylococcus aureus (S. aureus ATCC 25923) under UV-light and dark conditions. It was found that the Fe3O4@SiO2-SO3H was significantly indicated the higher photocatalytic inactivation than both Fe3O4 and Fe3O4@SiO2 against E. coli in compared with S. aureus. Furthermore, the inactivation efficiency against both organisms under light conditions has been higher than this efficiency under dark conditions.

  19. Analysis and detection of the herbicides dimethenamid and flufenacet and their sulfonic and oxanilic acid degradates in natural water

    USGS Publications Warehouse

    Zimmerman, L.R.; Schneider, R.J.; Thurman, E.M.

    2002-01-01

    Dimethenamid [2-chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide] and flufenacet [N-(4-fluorophenyl)-N-(1-methylethyl)-2-(5-(trifluoromethyl)-1,3,4- thiadiazol-2-yl)oxy] were isolated by C-18 solid-phase extraction and separated from their ethanesulfonic acid (ESA) and oxanilic acid (OXA) degradates during their elution using ethyl acetate for the parent compound, followed by methanol for the polar degradates. The parent compounds were detected using gas chromatography-mass spectrometry in selected-ion mode. The ESA and OXA degradates were detected using high-performance liquid chromatography-electrospray mass spectrometry (HPLC-ESPMS) in negative-ion mode. The method detection limits for a 123-mL sample ranged from 0.01 to 0.07 μg/L. These methods are compatible with existing methods and thus allow for analysis of 17 commonly used herbicides and 18 of their degradation compounds with one extraction. In a study of herbicide transport near the mouth of the Mississippi River during 1999 and 2000, dimethenamid and its ESA and OXA degradates were detected in surface water samples during the annual spring flushes. For flufenacet, the only detections at the study site were for the ESA degradates in samples collected at the peak of the herbicide spring flush in 2000. The low frequency of detections in surface water likely is due to dimethenamid and flufenacet being relatively new herbicides. In addition, detectable amounts of the stable degradates have not been detected in ground water.

  20. Investigation of mitigating effect of colon-specific prodrugs of boswellic acid on 2,4,6-trinitrobenzene sulfonic acid-induced colitis in Wistar rats: Design, kinetics and biological evaluation

    PubMed Central

    Sarkate, Ajinkya; Dhaneshwar, Suneela S

    2017-01-01

    AIM To develop a colon-targeting bioreversible delivery system for β-boswellic acid (BBA) and explore utility of its prodrugs in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. METHODS Synthesis of 4 co-drugs of BBA with essential amino acids was achieved by CDI coupling, followed by their spectral characterization. In vitro kinetics were studied by HPLC in aqueous buffers, homogenates of gastrointestinal tract and fecal matter. In vivo kinetic studies were performed in Wistar rat plasma, urine and feces. The prodrugs were screened in TNBS-induced colitis modeled Wistar rats. Statistical significance was assumed at P < 0.05, P < 0.01, P < 0.001 when compared with disease controls using one-way and two-way ANOVAs. RESULTS Prodrugs were stable in 0.05 mol/L HCl buffer (pH 1.2) and stomach homogenates. Negligible hydrolysis was observed in phosphate buffer and intestinal homogenates. Substantial release (55%-72% and 68%-86%) of BBA was achieved in rat fecal matter and homogenates of colon. In vivo studies of BBA with L-tryptophan (BT) authenticated colon-specific release of BBA. But, surprisingly substantial concentration of BBA was seen to reach the systemic circulation due to probable absorption through colonic mucosa. Site-specifically enhanced bioavailability of BBA could be achieved in colon, which resulted in demonstration of significant mitigating effect on TNBS-induced colitis in rats without inducing any adverse effects on stomach, liver and pancreas. Prodrug of BT was found to be 1.7% (P < 0.001) superior than sulfasalazine in reducing the inflammation to colon among all prodrugs tested. CONCLUSION The outcome of this study strongly suggests that these prodrugs might have dual applicability to inflammatory bowel disease and chronotherapy of rheumatoid arthritis. PMID:28275295

  1. Evaluation of biochemical effects related to perfluorooctane sulfonic acid exposure in organohalogen-contaminated great tit (Parus major) and blue tit (Parus caeruleus) nestlings.

    PubMed

    Hoff, Philippe Tony; Van de Vijver, Kristin; Dauwe, Tom; Covaci, Adrian; Maervoet, Johan; Eens, Marcel; Blust, Ronny; De Coen, Wim

    2005-12-01

    A perfluorooctane sulfonic acid (PFOS) biomonitoring survey was conducted on great tit (Parus major) and blue tit (Parus caeruleus) nestlings from Blokkersdijk, a bird reserve in the proximity of a fluorochemical plant in Antwerp (Belgium) and Fort IV, a control area. PFOS, together with 11 organochlorine pesticides, 20 polychlorinated biphenyl congeners and 7 polybrominated diphenyl ethers were measured in liver tissue. The hepatic PFOS concentrations at Blokkersdijk (86-2788 and 317-3322 ng/g wet weight (ww) for great and blue tit, respectively) were among the highest ever measured and were significantly higher than at the control area (17-206 and 69-514 ng/g ww for great and blue tit, respectively). The hepatic PFOS concentration was species- and sex-independent and correlated significantly and positively with the serum alanine aminotransferase activity and negatively with the serum cholesterol and triglyceride levels in both species but did not correlate with condition or serum protein concentration. In the great tit, a significant positive correlation was observed between the liver PFOS concentration and the relative liver weight. In the blue tit, the hepatic PFOS concentration correlated positively and significantly with hematocrite values. None of the investigated organohalogen pollutants except for PFOS were suggested to be involved in the observed biological alterations.

  2. Perfluorooctane sulfonic acid and organohalogen pollutants in liver of three freshwater fish species in Flanders (Belgium): relationships with biochemical and organismal effects.

    PubMed

    Hoff, Philippe Tony; Van Campenhout, Karen; Van de Vijver, Kristin; Covaci, Adrian; Bervoets, Lieven; Moens, Lotte; Huyskens, Geert; Goemans, Geert; Belpaire, Claude; Blust, Ronny; De Coen, Wim

    2005-09-01

    A perfluorooctane sulfonic acid (PFOS) assessment was conducted on gibel carp (Carassius auratus gibelio), carp (Cyprinus carpio), and eel (Anguilla anguilla) in Flanders (Belgium). The liver PFOS concentrations in fish from the Ieperlee canal (Boezinge, 250-9031 ng/g wet weight, respectively) and the Blokkersdijk pond (Antwerp, 633-1822 ng/g wet weight) were higher than at the Zuun basin (Sint-Pieters-Leeuw, 11.2-162 ng/g wet weight) and among the highest in feral fish worldwide. Eel from the Oude Maas pond (Dilsen-Stokkem) and Watersportbaan basin (Ghent) had PFOS concentrations ranging between 212 and 857 ng/g wet weight. The hepatic PFOS concentration was significantly and positively related with the serum alanine aminotransferase activity, and negatively with the serum protein content in eel and carp. The hepatic PFOS concentration in carp correlated significantly and negatively with the serum electrolyte concentrations whereas a significant positive relation was found with the hematocrit in eel. Although 13 organochlorine pesticides, 22 polychlorinated biphenyl (PCB) congeners and 7 polybrominated diphenyl ethers (PBDEs) were also measured in the liver tissue, only PCB 28, PCB 74, gamma-hexachlorocyclohexane (gamma-HCH) and hexachlorobenzene (HCB) were suggested to contribute to the observed serological alterations in eel.

  3. Appropriateness of reference genes for normalizing messenger RNA in mouse 2,4-dinitrobenzene sulfonic acid (DNBS)-induced colitis using quantitative real time PCR

    PubMed Central

    Eissa, Nour; Kermarrec, Laëtitia; Hussein, Hayam; Bernstein, Charles N.; Ghia, Jean-Eric

    2017-01-01

    2,4-Dinitrobenzene sulfonic acid (DNBS)-induced colitis is an experimental model that mimics Crohn’s disease. Appropriateness of reference genes is crucial for RT-qPCR. This is the first study to determine the stability of reference gene expression (RGE) in mice treated with DNBS. DNBS experimental Colitis was induced in male C57BL/6 mice. RNA was extracted from colon tissue and comprehensive analysis of 13 RGE was performed according to predefined criteria. Relative colonic TNF-α and IL-1β mRNA levels were calculated. Colitis significantly altered the stability of mucosal RGE. Commonly used glyceraldehyde-3-phosphate dehydrogenase (Gapdh), β-actin (Actb), or β2-microglobulin (β2m) showed the highest fluctuation within the inflamed and control groups. Conversely, ribosomal protein large P0 (Rplp0), non-POU domain containing (Nono), TATA-box-binding protein (Tbp) and eukaryotic translation elongation factor 2 (Eef2) were not affected by inflammation and were the most stable genes. TNF-α and IL-1β mRNA levels was dependent on the reference gene used and varied from significant when the most stable genes were used to non-significant when the least stable genes were used. The appropriate choice of RGE is critical to guarantee satisfactory normalization of RT-qPCR data when using DNBS-Model. We recommend using Rplp0, Nono, Tbp, Hprt and Eef2 instead of common reference genes. PMID:28186172

  4. A targeted/non-targeted screening method for perfluoroalkyl carboxylic acids and sulfonates in whole fish using quadrupole time-of-flight mass spectrometry and MS(e).

    PubMed

    Crimmins, Bernard S; Xia, Xiaoyan; Hopke, Philip K; Holsen, Thomas M

    2014-02-01

    A new method for measuring perfluoroalkyl contaminants (PFCs) in biological matrices has been developed. An ultra-high pressure liquid chromatograph equipped with a quadrupole time-of-flight mass spectrometer (UPLC-QToF) was optimized using a continuous precursor/product ion monitoring mode. Unlike traditional targeted studies that isolate precursor/product ion pairs, the current method alternates between two ionization energy channels to continuously capture standard electrospray ionization (low energy) and collision induced dissociation (high energy) spectra. The result is the indiscriminant acquisition of paired low and high energy spectra for all constituents eluting from the chromatographic system. This technique was evaluated for the routine analysis of perfluoroalkyl species. Using this technique, linear perfluoroalkyl carboxylic acids (C4 to C14) and perfluoroalkyl sulfonates (C4, C6, C8 and C10) exhibited a linear range spanning over three orders of magnitude and were detectable at levels less than 1 pg on column with a root mean squared signal to noise ratio of 5 to 20. Lake trout (Salvelinus namaycush) and National Institutes of Standards and Technology Standard Reference Material 1946 were used to evaluate matrix effects and the accuracy of this method when applied to a whole fish extract. The current method was also evaluated as a diagnostic tool to identify unknown PFCs using experimental fragmentation patterns, mass defect filtering and Kendrick plots.

  5. Therapeutic effects of human amnion-derived mesenchymal stem cell transplantation and conditioned medium enema in rats with trinitrobenzene sulfonic acid-induced colitis

    PubMed Central

    Miyamoto, Shuichi; Ohnishi, Shunsuke; Onishi, Reizo; Tsuchiya, Ikuki; Hosono, Hidetaka; Katsurada, Takehiko; Yamahara, Kenichi; Takeda, Hiroshi; Sakamoto, Naoya

    2017-01-01

    Cell therapy with mesenchymal stem cells (MSCs) is expected to provide a new strategy for the treatment of inflammatory bowel disease (IBD). Large amounts of MSCs can be obtained from human amnion. Therefore, we investigated the effect of transplantation of human amnion-derived MSCs (hAMSCs) or enema of conditioned medium (CM) from hAMSCs into rats with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. In the first experiment, 10-week-old male Sprague-Dawley rats were intravenously injected with hAMSCs (1 × 106 cells) 3 h after rectal administration of TNBS (45 mg/kg). In the second experiment, rats with TNBS-induced colitis received CM by enema into the colon for 3 days. Colitis was investigated by endoscopy, histology, immunohistochemistry, and by measuring mRNA expression of inflammatory mediators. Administration of hAMSCs or CM enema significantly improved the endoscopic score. In addition, these two interventions resulted in significantly decreased infiltration of neutrophils and monocytes/macrophages and decreased expression levels of TNF-α, CXCL1, and CCL2. In conclusion, transplantation of hAMSCs and CM enema provided significant improvement in rats with TNBS-induced colitis. CM from hAMSCs and hAMSCs may be new strategies for the treatment of IBD. PMID:28386323

  6. Self-assembled platinum nanoparticles on sulfonic acid-grafted graphene as effective electrocatalysts for methanol oxidation in direct methanol fuel cells

    PubMed Central

    Lu, Jinlin; Li, Yanhong; Li, Shengli; Jiang, San Ping

    2016-01-01

    In this article, sulfonic acid-grafted reduced graphene oxide (S-rGO) were synthesized using a one-pot method under mild conditions, and used as Pt catalyst supports to prepare Pt/S-rGO electrocatalysts through a self-assembly route. The structure, morphologies and physicochemical properties of S-rGO were examined in detail by techniques such as atomic force microscope (AFM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The S-rGO nanosheets show excellent solubility and stability in water and the average particle size of Pt nanoparticles supported on S-rGO is ~3.8 nm with symmetrical and uniform distribution. The electrocatalytic properties of Pt/S-rGO were investigated for methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). In comparison to Pt supported on high surface area Vulcan XC-72 carbon (Pt/VC) and Pt/rGO, the Pt/S-rGO electrocatalyst exhibits a much higher electrocatalytic activity, faster reaction kinetics and a better stability. The results indicate that Pt/S-rGO is a promising and effective electrocatalyst for MOR of DMFCs. PMID:26876468

  7. Use of dynamic simulation to assess the behaviour of linear alkyl benzene sulfonates and their biodegradation intermediates (sulfophenylcarboxylic acids) in estuaries

    NASA Astrophysics Data System (ADS)

    García-Luque, E.; González-Mazo, E.; Forja, J. M.; Gómez-Parra, A.

    2009-02-01

    Dynamic laboratory simulation of processes affecting chemical species in their transit through estuaries is a very useful tool to characterize these littoral systems. To date, laboratory studies concerning biodegradation and sorption (onto suspended particulate matter) of LAS in an estuary are scarce. For this reason, a dynamic automated estuarine simulator has been employed to carry out different experiments in order to assess the biodegradability of linear alkyl benzene sulfonates (LAS) and their biodegradation intermediates (sulfophenylcarboxylic acids, SPCs) using environmentally representative LAS concentrations in estuaries by a continuous injection of LAS into the system. During the experiments, a great affinity of LAS for the solid phase has been found, as well as an increased adsorption in line with increased chain length. On the other hand, the presence of SPCs with chain length between 6 and 13 carbon atoms was detected. Accumulation and persistence of medium chain length SPCs (C 6-C 8) along the experiments show that their degradation constitutes the limiting step for the process of LAS mineralization. In the final zone of the simulated estuarine system, the levels of SPCs were below the limits of detection. Thus, the disappearance of SPCs indicated that LAS biodegradation had been completed along the estuary. Similar results have been described for different Iberian littoral ecosystems. Therefore, the simulator employed in this research appears to be a useful tool to anticipate the behaviour of a xenobiotic chemical in its transit through littoral systems with different salinity gradients.

  8. Self-assembled platinum nanoparticles on sulfonic acid-grafted graphene as effective electrocatalysts for methanol oxidation in direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Lu, Jinlin; Li, Yanhong; Li, Shengli; Jiang, San Ping

    2016-02-01

    In this article, sulfonic acid-grafted reduced graphene oxide (S-rGO) were synthesized using a one-pot method under mild conditions, and used as Pt catalyst supports to prepare Pt/S-rGO electrocatalysts through a self-assembly route. The structure, morphologies and physicochemical properties of S-rGO were examined in detail by techniques such as atomic force microscope (AFM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The S-rGO nanosheets show excellent solubility and stability in water and the average particle size of Pt nanoparticles supported on S-rGO is ~3.8 nm with symmetrical and uniform distribution. The electrocatalytic properties of Pt/S-rGO were investigated for methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). In comparison to Pt supported on high surface area Vulcan XC-72 carbon (Pt/VC) and Pt/rGO, the Pt/S-rGO electrocatalyst exhibits a much higher electrocatalytic activity, faster reaction kinetics and a better stability. The results indicate that Pt/S-rGO is a promising and effective electrocatalyst for MOR of DMFCs.

  9. Simultaneous determination of caffeine and paracetamol by square wave voltammetry at poly(4-amino-3-hydroxynaphthalene sulfonic acid)-modified glassy carbon electrode.

    PubMed

    Tefera, Molla; Geto, Alemnew; Tessema, Merid; Admassie, Shimelis

    2016-11-01

    Poly(4-amino-3-hydroxynaphthalene sulfonic acid)-modified glassy carbon electrode (poly(AHNSA)/GCE) was prepared for simultaneous determination of caffeine and paracetamol using square-wave voltammetry. The method was used to study the effects of pH and scan rate on the voltammetric response of caffeine and paracetamol. Linear calibration curves in the range of 10-125μM were obtained for both caffeine and paracetamol in acetate buffer solution of pH 4.5 with a correlation coefficient of 0.9989 and 0.9986, respectively. The calculated detection limits (S/N=3) were 0.79μM for caffeine and 0.45μM for paracetamol. The effects of some interfering substances in the determination of caffeine and paracetamol were also studied and their interferences were found to be negligible which proved the selectivity of the modified electrode. The method was successfully applied for the quantitative determination of caffeine and paracetamol in Coca-Cola, Pepsi-Cola and tea samples.

  10. Sensitive and selective colorimetric detection of glutathione in human plasma with 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and Ag+ ion

    NASA Astrophysics Data System (ADS)

    Li, Yinhuan; Liu, Xiaoying; Zhang, Ruyi

    2017-02-01

    Glutathione is of vital importance to human beings through involving in many cellular functions. Simple and sensitive methods capable of detecting glutathione in biological samples are significant to diagnosis and prevention of disease. Here a simple, label-free, and sensitive colorimetric method was developed for the determination of glutathione. It was observed that Ag+ ion could directly oxidize 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), a commonly used peroxidase substrate, to produce a green solution, which possessed a maximum absorbance at 420 nm. The presence of glutathione hindered the oxidation process and decreased the absorbance at 420 nm owing to its ability to bind with Ag+ ion. The procedure allowed the measurement of 0.1-4.0 μM glutathione with a detection limit of 59 nM. The relative standard deviation was 1.8% in eleven replicated measurements of 1.0 μM glutathione solution. The method was applied to the determination of glutathione in human plasma with satisfactory results.

  11. One-step electrochemical synthesis of 6-amino-4-hydroxy-2-napthalene-sulfonic acid functionalized graphene for green energy storage electrode materials

    NASA Astrophysics Data System (ADS)

    Kuila, Tapas; Khanra, Partha; Kim, Nam Hoon; Kuk Choi, Sung; Yun, Hyung Joong; Lee, Joong Hee

    2013-09-01

    A green approach for the one-step electrochemical synthesis of water dispersible graphene is reported. An alkaline solution of 6-amino-4-hydroxy-2-naphthalene-sulfonic acid (ANS) serves the role of electrolyte as well as surface modifier. High-purity graphite rods are used as electrodes which can be exfoliated under a constant electrical potential (˜20 V) to form ANS functionalized graphene (ANEG). The aqueous dispersion of ANEG obeyed Beer’s law at moderate concentrations, as evidenced from ultraviolet-visible spectroscopy analysis. X-ray diffraction analysis suggests complete exfoliation of graphite into graphene. Fourier transform infrared and x-ray photoelectron spectroscopy not only confirm the functionalization of graphene with ANS, but also suggest the formation of oxygen containing functional groups on the surface of ANEG. Raman spectra analysis indicates the presence of defects in ANEG as compared to pure graphite. Cyclic voltammetry and charge-discharge measurements of ANEG using three electrode systems show a specific capacitance of 115 F g-1 at a current density of 4 A g-1. The ANEG electrode exhibits 93% retention in specific capacitance after 1000 charge-discharge cycles, confirming its utility as a green energy storage electrode material.

  12. An alternative standard for Trolox-equivalent antioxidant-capacity estimation based on thiol antioxidants. Comparative 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] decolorization and rotational viscometry study regarding hyaluronan degradation.

    PubMed

    Hrabárová, Eva; Valachová, Katarína; Rapta, Peter; Soltés, Ladislav

    2010-09-01

    Comparison of the effectiveness of antioxidant activity of three thiol compounds, D-penicillamine, reduced L-glutathione, and 1,4-dithioerythritol, expressed as a radical-scavenging capacity based on the two independent methods, namely a decolorization 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay and a rotational viscometry, is reported. Particular concern was focused on the testing of potential free-radical scavenging effects of thiols against hyaluronan degradation, induced by hydroxyl radicals. A promising, solvent-independent, antioxidative function of 1,4-dithioerythritol, comparable to that of a standard compound, Trolox(®), was confirmed by the 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay. The new potential antioxidant 1,4-dithioerythritol exhibited very good solubility in a variety of solvents (e.g., H(2)O, EtOH, and DMSO) and could be widely accepted and used as an effective antioxidant standard instead of a routinely used Trolox(®) on 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay.

  13. Alternative hybrid electrolytes based on a series of bis(trialkoxysilyl)alkanes and 3-(trihydroxysilyl)-1-propane sulfonic acid applied in gas diffusion electrodes of proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Lin, C. W.; Chung, L. C.; Veerapur, R. S.; Yang, F. C.

    This study demonstrates a method for improving the electrolyte distribution in catalyst layers and enhancing the utilization of catalyst existing in primary pores. Bis(trialkoxysilyl)alkanes (BTAS-alkanes) and 3-(trihydroxysilyl)-1-propane sulfonic acid (THS)Pro-SO 3H) precursors have been used to prepare a series of hybrid electrolytes with various organic segment lengths of BTAS-alkanes and ratios of organic moiety and sulfonic acid groups. Investigations of BTAS-alkanes series includes bis(triethoxysilyl)octane (BTES-Oct), bis(trimethoxysilyl)hexane (BTMS-Hex), and bis(triethoxysilyl)ethane (BTES-Eth). Small angle X-ray spectroscopy (SAXS) identifies morphological phase separation in BTES-Oct and BTMS-Hex hybrid electrolytes. The results of mercury porosimetry and BET porosimetry show that the hybrid electrolytes have better capability than Nafion ionomer to penetrate into primary pores of the catalyst layers. Electrochemical measurements including electrode polarization, electrochemical active surface (EAS) and electrochemical impedance spectroscopy (EIS) are discussed. The BTES-Oct or BTMS-Hex hybrid electrolytes with higher ratio of organic moiety and sulfonic acid group have achieved better electrode performance. Oxygen benefit current (OBC) results indicate that higher ratios of BTES-Oct/(THS)Pro-SO 3H provides higher hydrophobicity with better gas transport properties. However, the hybrid electrodes exhibit lower cathode performance than Nafion ®-based electrodes due to excessive electrolyte incorporated in the catalyst layer.

  14. Effects of mimic of manganese superoxide dismutase on 2,4,6-trinitrobenzene sulfonic acid-induced colitis in rats.

    PubMed

    Wang, Yan-Hong; Dong, Jiao; Zhang, Jian-Xin; Zhai, Jing; Ge, Bin

    2016-09-01

    The mimic of manganese superoxide dismutase (MnSODm) has been synthesized and reported to have anti-inflammatory properties. However, whether MnSODm has anti-inflammatory effects on colitis and any underlying mechanisms are poorly understood. This study was to investigate therapeutic effects and mechanism of MnSODm on 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced colitis model in rats. Rats were intragastrically administered MnSODm (10, 20, and 40 mg/kg) per day for 7 days after colitis was induced by TNBS. After treated with MnSODm, the colonic macroscopic and microscopic damage scores and colonic weight/length ratios were significantly decreased compared with colitis model group. Myeloperoxidase (MPO) activity, malonyldialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8 levels in colon tissues were also significantly decreased in MnSODm treatment groups. However, superoxide dismutase (SOD) activity significantly increased and phosphorylated inhibitory kappa B-alpha (IκBα), inhibitor kappa B kinase (IKKα/β), and nuclear factor-kappa Bp65 (NF-κBp65) as well as Toll-like receptor 4 (TLR4) and myeloid differentiation actor 88 (MyD88) in the colonic mucosa were significantly inhibited by MnSODm treatment. Thus, MnSODm was protective against colitis via antioxidant activity and by inhibiting inflammatory mediators by down-regulating TLR4/MyD88/NF-κB signaling pathways. These data suggest a potential therapeutic effect of MnSODm in colitis.

  15. Design, Synthesis, and Crystal Structures of 6-Alkylidene-2 -Substituted Penicillanic Acid Sulfones as Potent Inhibitors of Acinetobacter baumannii OXA-24 Carbapenemase

    SciTech Connect

    Bou, G.; Santillana, E; Sheri, A; Beceiro, A; Sampson, J; Kalp, M; Bethel, C; Distler, A; Drawz, S; et. al.

    2010-01-01

    Class D {beta}-lactamases represent a growing and diverse class of penicillin-inactivating enzymes that are usually resistant to commercial {beta}-lactamase inhibitors. As many such enzymes are found in multi-drug resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa, novel {beta}-lactamase inhibitors are urgently needed. Five unique 6-alkylidene-2{prime}-substituted penicillanic acid sulfones (1-5) were synthesized and tested against OXA-24, a clinically important {beta}-lactamase that inactivates carbapenems and is found in A. baumannii. Based upon the roles Tyr112 and Met223 play in the OXA-24 {beta}-lactamase, we also engineered two variants (Tyr112Ala and Tyr112Ala,Met223Ala) to test the hypothesis that the hydrophobic tunnel formed by these residues influences inhibitor recognition. IC{sub 50} values against OXA-24 and two OXA-24 {beta}-lactamase variants ranged from 10 {+-} 1 (4 vs WT) to 338 {+-} 20 nM (5 vs Tyr112Ala, Met223Ala). Compound 4 possessed the lowest K{sub i} (500 {+-} 80 nM vs WT), and 1 possessed the highest inactivation efficiency (k{sub inact}/K{sub i} = 0.21 {+-} 0.02 {micro}M{sup -1}s{sup -1}). Electrospray ionization mass spectrometry revealed a single covalent adduct, suggesting the formation of an acyl-enzyme intermediate. X-ray structures of OXA-24 complexed to four inhibitors (2.0-2.6 {angstrom}) reveal the formation of stable bicyclic aromatic intermediates with their carbonyl oxygen in the oxyanion hole. These data provide the first structural evidence that 6-alkylidene-2{prime}-substituted penicillin sulfones are effective mechanism-based inactivators of class D {beta}-lactamases. Their unique chemistry makes them developmental candidates. Mechanisms for class D hydrolysis and inhibition are discussed, and a pathway for the evolution of the BlaR1 sensor of Staphylococcus aureus to the class D {beta}-lactamases is proposed.

  16. Crystal Structures of KPC-2[beta]-Lactamase in Complex with 3-Nitrophenyl Boronic Acid and the Penam Sulfone PSR-3-226

    SciTech Connect

    Ke, Wei; Bethel, Christopher R.; Papp-Wallace, Krisztina M.; Pagadala, Sundar Ram Reddy; Nottingham, Micheal; Fernandez, Daniel; Buynak, John D.; Bonomo, Robert A.; van den Akker, Focco

    2012-08-01

    Class A carbapenemases are a major threat to the potency of carbapenem antibiotics. A widespread carbapenemase, KPC-2, is not easily inhibited by {beta}-lactamase inhibitors (i.e., clavulanic acid, sulbactam, and tazobactam). To explore different mechanisms of inhibition of KPC-2, we determined the crystal structures of KPC-2 with two {beta}-lactamase inhibitors that follow different inactivation pathways and kinetics. The first complex is that of a small boronic acid compound, 3-nitrophenyl boronic acid (3-NPBA), bound to KPC-2 with 1.62-{angstrom} resolution. 3-NPBA demonstrated a Km value of 1.0 {+-} 0.1 {micro}M (mean {+-} standard error) for KPC-2 and blocks the active site by making a reversible covalent interaction with the catalytic S70 residue. The two boron hydroxyl atoms of 3-NPBA are positioned in the oxyanion hole and the deacylation water pocket, respectively. In addition, the aromatic ring of 3-NPBA provides an edge-to-face interaction with W105 in the active site. The structure of KPC-2 with the penam sulfone PSR-3-226 was determined at 1.26-{angstrom} resolution. PSR-3-226 displayed a K{sub m} value of 3.8 {+-} 0.4 {micro}M for KPC-2, and the inactivation rate constant (kinact) was 0.034 {+-} 0.003 s{sup -1}. When covalently bound to S70, PSR-3-226 forms a trans-enamine intermediate in the KPC-2 active site. The predominant active site interactions are generated via the carbonyl oxygen, which resides in the oxyanion hole, and the carboxyl moiety of PSR-3-226, which interacts with N132, N170, and E166. 3-NPBA and PSR-3-226 are the first {beta}-lactamase inhibitors to be trapped as an acyl-enzyme complex with KPC-2. The structural and inhibitory insights gained here could aid in the design of potent KPC-2 inhibitors.

  17. Reprint of: Liquid chromatographic enzymatic studies with on-line Beta-secretase immobilized enzyme reactor and 4-(4-dimethylaminophenylazo) benzoic acid/5-[(2-aminoethyl) amino] naphthalene-1-sulfonic acid peptide as fluorogenic substrate.

    PubMed

    De Simone, Angela; Seidl, Claudia; Santos, Cid Aimbiré M; Andrisano, Vincenza

    2014-10-01

    High throughput screening (HTS) techniques are required for the fast hit inhibitors selection in the early discovery process. However, in Beta-secretase (BACE1) inhibitors screening campaign, the most frequently used methoxycoumarin based peptide substrate (M-2420) is not widely applicable when aromatic or heterocycle compounds of natural source show auto-fluorescence interferences. Here, in order to overcome these drawbacks, we propose the use of a highly selective 4-(4-dimethylaminophenylazo)benzoic acid/5-[(2-aminoethyl)amino]naphthalene-1-sulfonic acid (DABCYL/1,5-EDANS) based peptide substrate (Substrate IV), whose cleavage product is devoid of spectroscopic interference. HrBACE1-IMER was prepared and characterized in terms of units of immobilised hrBACE1. BACE1 catalyzed Substrate IV cleavage was on-line kinetically characterized in terms of KM and vmax, in a classical Michaelis and Menten study. The on-line kinetic constants were found consistent with those obtained with the in solution fluorescence resonance energy transfer (FRET) standard method. In order to further validate the use of Substrate IV for inhibition studies, the inhibitory potency of the well-known BACE1 peptide InhibitorIV (IC₅₀: 0.19 ± 0.02 μM) and of the natural compound Uleine (IC₅₀: 0.57 ± 0.05) were determined in the optimized on-line hrBACE1-IMER. The IC₅₀ values on the hrBACE1-IMER system were found in agreement with that obtained by the conventional methods confirming the applicability of Substrate IV for on-line BACE1 kinetic and inhibition studies.

  18. Liquid chromatographic enzymatic studies with on-line Beta-secretase immobilized enzyme reactor and 4-(4-dimethylaminophenylazo) benzoic acid/5-[(2-aminoethyl) amino] naphthalene-1-sulfonic acid peptide as fluorogenic substrate.

    PubMed

    De Simone, Angela; Seidl, Claudia; Santos, Cid Aimbiré M; Andrisano, Vincenza

    2014-03-15

    High throughput screening (HTS) techniques are required for the fast hit inhibitors selection in the early discovery process. However, in Beta-secretase (BACE1) inhibitors screening campaign, the most frequently used methoxycoumarin based peptide substrate (M-2420) is not widely applicable when aromatic or heterocycle compounds of natural source show auto-fluorescence interferences. Here, in order to overcome these drawbacks, we propose the use of a highly selective 4-(4-dimethylaminophenylazo)benzoic acid/5-[(2-aminoethyl)amino]naphthalene-1-sulfonic acid (DABCYL/1,5-EDANS) based peptide substrate (Substrate IV), whose cleavage product is devoid of spectroscopic interference. HrBACE1-IMER was prepared and characterized in terms of units of immobilised hrBACE1. BACE1 catalyzed Substrate IV cleavage was on-line kinetically characterized in terms of KM and vmax, in a classical Michaelis and Menten study. The on-line kinetic constants were found consistent with those obtained with the in solution fluorescence resonance energy transfer (FRET) standard method. In order to further validate the use of Substrate IV for inhibition studies, the inhibitory potency of the well-known BACE1 peptide InhibitorIV (IC50: 0.19±0.02μM) and of the natural compound Uleine (IC50: 0.57±0.05) were determined in the optimized on-line hrBACE1-IMER. The IC50 values on the hrBACE1-IMER system were found in agreement with that obtained by the conventional methods confirming the applicability of Substrate IV for on-line BACE1 kinetic and inhibition studies.

  19. Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker responses in east Greenland polar bears (Ursus maritimus).

    PubMed

    Eggers Pedersen, Kathrine; Basu, Niladri; Letcher, Robert; Greaves, Alana K; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

    2015-04-01

    Perfluoroalkyl substances (PFASs) is a growing class of contaminants in the Arctic environment, and include the established perfluorinated sulfonates (PFSAs; especially perfluorooctane sulfonate (PFOS)) and carboxylic acids (PFCAs). PFSAs and PFCAs of varying chain length have been reported to bioaccumulate in lipid rich tissues of the brain among other tissues such as liver, and can reach high concentrations in top predators including the polar bear. PFCA and PFSA bioaccummulation in the brain has the potential to pose neurotoxic effects and therefore we conducted a study to investigate if variations in neurochemical transmitter systems i.e. the cholinergic, glutaminergic, dopaminergic and GABAergic, could be related to brain-specific bioaccumulation of PFASs in East Greenland polar bears. Nine brain regions from nine polar bears were analyzed for enzyme activity (monoamine oxidase (MAO), acetylcholinesterase (AChE) and glutamine synthetase (GS)) and receptor density (dopamine-2 (D2), muscarinic cholinergic (mAChR) and gamma-butyric acid type A (GABA-A)) along with PFSA and PFCA concentrations. Average brain ∑PFSA concentration was 25ng/g ww where PFOS accounted for 91%. Average ∑PFCA concentration was 88ng/g ww where PFUnDA, PFDoDA and PFTrDA combined accounted for 79%. The highest concentrations of PFASs were measured in brain stem, cerebellum and hippocampus. Correlative analyses were performed both across and within brain regions. Significant positive correlations were found between PFASs and MAO activity in occipital lobe (e.g. ∑PFCA; rp=0.83, p=0.041, n=6) and across brain regions (e.g. ∑PFCA; rp=0.47, p=0.001, ∑PFSA; rp=0.44, p>0.001; n=50). GABA-A receptor density was positively correlated with two PFASs across brain regions (PFOS; rp=0.33, p=0.02 and PFDoDA; rp=0.34, p=0.014; n=52). Significant negative correlations were found between mAChR density and PFASs in cerebellum (e.g. ∑PFCA; rp=-0.95, p=0.013, n=5) and across brain regions (e.g.

  20. Anionic-zwitterionic mixed micelles in micellar electrokinetic chromatography: sodium dodecyl sulfate-N-dodecyl-N,N-dimethylammonium-3-propane-1-sulfonic acid.

    PubMed

    Ahuja, E S; Preston, B P; Foley, J P

    1994-07-15

    A zwitterionic surfactant, N-dodecyl-N,N-dimethylammonium-3-propane-1- sulfonic acid (SB-12), was used in combination with an anionic surfactant, sodium dodecyl sulfate (SDS), to form a novel pseudostationary phase for use in micellar electrokinetic chromatography. This mixed micellar system was characterized in terms of analyte retention, selectivity, efficiency, elution range, and resolution; and compared to results obtained using only SDS. A typically used SDS concentration, 20 mM, was chosen as a reference to which comparisons could be drawn. With 20 mM SDS, the optimum concentration range of 10-20 mM SB-12 provided efficiencies that were 2-4 times greater than with SDS alone, with minimal (< 15%) changes in the elution range and electroosmotic flow. The addition of 40 and 60 mM SB-12 also resulted in efficiencies on average of 600,000-800,000 theoretical plates/m, but at a significant reduction in the elution range and peak capacity. Retention factors (k') for the various neutral analytes increased by 20% with addition of 10 mM SB-12 and by approximately 60% with addition of 40 and 60 mM SB-12, while operating currents remained constant as SB-12 was added. Geometrical isomers p-nitrotoluene and m-nitrotoluene, that co-eluted with 20 mM SDS, were baseline resolved with the addition of 10 mM SB-12; in addition, methylene selectivity was greatest at this composition. No capillary wall interactions or coating effects were observed with the SDS-SB-12 mixed micellar system, in contrast to previously studied anionic-non-ionic mixed micellar system, SDS-Brij 35. Consequently, migration times were very repeatable (< or = 1.2% R.S.D.).

  1. Detecting a Quasi-stable Imine Species on the Reaction Pathway of SHV-1 β-Lactamase and 6β-(Hydroxymethyl)penicillanic Acid Sulfone

    PubMed Central

    2015-01-01

    For the class A β-lactamase SHV-1, the kinetic and mechanistic properties of the clinically used inhibitor sulbactam are compared with the sulbactam analog substituted in its 6β position by a CH2OH group (6β-(hydroxymethyl)penicillanic acid). The 6β substitution improves both in vitro and microbiological inhibitory properties of sulbactam. Base hydrolysis of both compounds was studied by Raman and NMR spectroscopies and showed that lactam ring opening is followed by fragmentation of the dioxothiazolidine ring leading to formation of the iminium ion within 3 min. The iminium ion slowly loses a proton and converts to cis-enamine (which is a β-aminoacrylate) in 1 h for sulbactam and in 4 h for 6β-(hydroxymethyl) sulbactam. Rapid mix–rapid freeze Raman spectroscopy was used to follow the reactions between the two sulfones and SHV-1. Within 23 ms, a 10-fold excess of sulbactam was entirely hydrolyzed to give a cis-enamine product. In contrast, the 6β-(hydroxymethyl) sulbactam formed longer-lived acyl–enzyme intermediates that are a mixture of imine and enamines. Single crystal Raman studies, soaking in and washing out unreacted substrates, revealed stable populations of imine and trans-enamine acyl enzymes. The corresponding X-ray crystallographic data are consonant with the Raman data and also reveal the role played by the 6β-hydroxymethyl group in retarding hydrolysis of the acyl enzymes. The 6β-hydroxymethyl group sterically hinders approach of the water molecule as well as restraining the side chain of E166 that facilitates hydrolysis. PMID:25536850

  2. Effects of morin-5'-sulfonic acid sodium salt (NaMSA) on cyclophosphamide-induced changes in oxido-redox state in rat liver and kidney.

    PubMed

    Merwid-Ląd, A; Trocha, M; Chlebda, E; Sozański, T; Magdalan, J; Ksiądzyna, D; Kopacz, M; Kuźniar, A; Nowak, D; Pieśniewska, M; Fereniec-Gołębiewska, L; Kwiatkowska, J; Szeląg, A

    2012-08-01

    Cyclophosphamide (CPX) is an anticancer drug with immunosuppressive properties. Its adverse effects are partly connected to the induction of oxidative stress. Some studies indicate that water-soluble derivative of morin-morin-5'-sulfonic acid sodium salt (NaMSA) exhibits strong antioxidant activity. The aim of present study was to evaluate the effect of NaMSA on CPX-induced changes in oxido-redox state in rat. Experiment was carried out on Wistar rats divided in three experimental groups (N = 12) receiving: 0.9% saline, CPX (15 mg/kg) or CPX (15 mg/kg) + NaMSA (100 mg/kg), respectively, and were given intragastrically for 10 days. Malondialdehyde (MDA) and glutathione (GSH) concentrations and superoxide dismutase (SOD) activity were determined in liver and kidneys. Catalase (CAT) activity was assessed only in liver. Treatment with CPX resulted in significant decrease in MDA level in both tissues, which was completely reversed by NaMSA treatment only in liver. In comparison to the control group significant decrease in SOD activity were observed in both tissues of CPX receiving group. In kidneys this parameter was fully restored by NaMSA administration. CPX evoked significant decrease in GSH concentration in kidneys, which was completely reversed by NaMSA treatment. No significant changes were seen in GSH levels and CAT activity between all groups in liver. Results of our study suggest that CPX may exert significant impact on oxido-redox state in both organs. NaMSA fully reversed the CPX-induced changes, especially MDA level in liver, SOD activity and GSH concentration in kidneys and it may be done by enhancement of activity/concentration of endogenous antioxidants.

  3. Combined effects of magnetic fields and temperature changes on 1-aminonaphthalene-8-sulfonic acid fluorescence in red blood cell ghost cell membrane

    NASA Astrophysics Data System (ADS)

    Iwasaka, M.; Yaoita, M.; Iwasawa, T.; Ueno, S.

    2006-04-01

    In the present study, we performed an experiment to clarify the possible effects of magnetic fields of up to 8 T on cell membrane fluidity by using red blood cell ghosts and a fluorescence dye, 1-aminonaphthalene-8-sulfonic acid (ANS). The time course of ANS emission at 480 nm under the influence of a magnetic field at 5 T was observed. The effects of multiple rapid temperature changes and magnetic fields were investigated. The emission intensity at 480 nm increased when the temperature of the cell holder was increased from 20 to 38-46 °C for 15 min. A change in temperature exhibited an increase in the fluidity of the lipid molecules in the cell membrane and increased the population of ANS molecules emitting light at 480 nm in the cell membrane, which is hydrophobic. A discontinuous change in fluorescence at 38-40 °C was exhibited under exposure to a magnetic field at 5 T, while the temperature dependency was continuous without exposure to the magnetic field. In addition, under exposure to the magnetic field, the fluorescence during a decrease in temperature from 38 to 20 °C remained at a level close to the fluorescence during an increase in temperature. The results indicated that the fluidity of the molecules in the cell membrane was decelerated by exposure to magnetic fields at 5 T. We speculated that the magnetic orientation in a part of the lipid membrane disturbed the release of ANS molecules from a hydrophobic region of the membrane.

  4. Magnetic graphene - polystyrene sulfonic acid nano composite: A dispersive cation exchange sorbent for the enrichment of aminoalcohols and ethanolamines from environmental aqueous samples.

    PubMed

    Chinthakindi, Sridhar; Purohit, Ajay; Singh, Varoon; Tak, Vijay; Dubey, D K; Pardasani, Deepak

    2015-12-04

    Present study aimed at graphene surface modification to achieve selective analyte binding in dispersive solid phase extraction. Magnetic graphene - polystyrene sulfonic acid (MG-PSS) cation exchange nano-composite was prepared by non-covalent wrapping method. Composite was characterized by FT-IR and zeta potential. Material exhibited good dispersion in water and high exchange capacity of 1.97±0.16mMg(-1). Prepared nano-sorbent was then exploited for the cation exchange extraction and gas chromatography mass spectrometric analysis of Chemical Weapons Convention relevant aminoalcohols and ethanolamines from aqueous samples. Extraction parameters such as sorbent amount, extraction time, desorption conditions and sample pH were optimized and effect of common matrix interferences such as polyethylene glycol and metal salts was also studied. Three milligram of sorbent per mL of sample with 20min of extraction time at room temperature afforded 70-81% recoveries of the selected analytes spiked at concentration level of 1μgmL(-1). Method showed good linearity in the studied range with r(2)≥0.993. The limits of detection and limits of quantification ranged from 23 to 54ngmL(-1) and 72 to 147ngmL(-1), respectively. The relative standard deviation for intra- and inter-day precision ranged from 4.6 to 10.2% and 7.4 to 14.8% respectively. Applicability of the method to different environmental samples as well as the proficiency tests conducted by the Organization for the Prohibition of Chemical Weapons (OPCW) was also ascertained.

  5. TOWARD A RISK ASSESSMENT OF PERFLUOROALKYL ACIDS

    EPA Science Inventory

    Perfluoroalkyl acids (PFAA) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS),and fluorotelomer alcoholsare surfactants that have wide applications in industrial and consumer products. Various fluorotelomer alcohols are known to be metabolized to perfluo...

  6. Poly(arlyene ether sulfone) based semi-interpenetrating polymer network membranes containing cross-linked poly(vinyl phosphonic acid) chains for fuel cell applications at high temperature and low humidity conditions

    NASA Astrophysics Data System (ADS)

    Kim, Kihyun; Heo, Pilwon; Ko, Taeyun; Kim, Ki-hyun; Kim, Sung-Kon; Pak, Chanho; Lee, Jong-Chan

    2015-10-01

    Semi-interpenetrating polymer network (semi-IPN) membranes are prepared by in-situ casting and thermal-initiated radical polymerization of vinyl phosphonic acid (VPA) and bis(2-(methacryloyloxy)ethyl) phosphate (BMAEP) in N,N-dimethylacetamide solutions of sulfonated poly(arylene ether sulfone) (SPAES). The incorporation of VPA units into the SPAES membranes improves proton conductivity especially at high temperature and low humidity conditions. In addition the cross-linker, BMAEP, prevents the decrease of the mechanical and chemical stabilities by the aliphatic linear poly(vinyl phosphonic acid) chains in the semi-IPN membranes, and furthermore the phosphonic acid group in BMAEP can prevent the decrease of the proton conductivity by the formation of cross-linked structures. Therefore, the resulting semi-IPN membranes show high proton conductivities up to 15 mS cm-1 at 120 °C and 40% RH. The fuel cell performance (187 mW cm-2 at 120 °C and 40% RH) of membrane-electrode assembly (MEA) from the semi-IPN membrane is found to be superior to that (145 mW cm-2 at 120 °C and 40% RH) of MEA from the SPAES membrane. The durability test result at the operating conditions indicates that the semi-IPN membrane is electrochemically very stable maintaining the low hydrogen cross-over and high power densities.

  7. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  8. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  9. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  10. Developmental Toxicity of Perfluoroalkyl Acid Mixtures in CD-1 Mice

    EPA Science Inventory

    Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and perfluorononanoic acid (PFNA) belong to a family of fluoro-organic compounds known as perfluoroalkyl acids (PFAAs). PFAAs have been widely used in industrial and commercial applications, and have been found to be...

  11. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  12. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  13. ACTIVATION OF MOUSE AND HUMAN PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS (PPAR ALPHA, GAMMA, BETA DELTA) BY PERFLUOROOCTANOIC ACID (PFOA) AND PERFLUOROOCTANE SULFONATE (PFOS)

    EPA Science Inventory

    This study evaluates the potential for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) to activate peroxisome proliferator-activated receptors (PPARs), using a transient transfection cell assay. Cos-1 cells were cultured in DMEM with fetal bovine serum (FBS) in ...

  14. Obeticholic Acid

    MedlinePlus

    Obeticholic acid is used alone or in combination with ursodiol (Actigall, Urso) to treat primary biliary cholangitis (PBC; a ... were not treated successfully with ursodiol alone. Obeticholic acid is in a class of medications called farnesoid ...

  15. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  16. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  17. Aristolochic Acids

    MedlinePlus

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  18. Ascorbic Acid

    MedlinePlus

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  19. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  20. Amino acids

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  1. Effect of morin-5'-sulfonic acid sodium salt on the expression of apoptosis related proteins caspase 3, Bax and Bcl 2 due to the mercury induced oxidative stress in albino rats.

    PubMed

    Venkatesan, Rantham Subramaniam; Sadiq, Abdul Majeeth Mohamed

    2017-01-01

    Many environmental contaminants have been reported to disturb the pro-oxidant or antioxidant balance of the cells by inducing oxidative stress. Oxidative stress mediated by the HgCl2 induces DNA, protein and lipid oxidation resulted in necrosis or apoptosis, or both. Currently flavonoids are being emerging topic and reported to have antiviral, anti-inflammatory, anti- tumor and antioxidant activities. Morin is one of the flavonoid protects the cells from oxygen free radical damage and scavenges the free radicals and metals and also heals the injured cells commercially. Morin hydrate is sparingly soluble in water. Hence, the water soluble morin -5'- sulfonic acid sodium salt (NaMSA) was selected and synthesized. Aim of the present study was to analyze the effect of morin-5'-sulfonic acid sodium salt on the expression of apoptosis related proteins caspase 3, Bax and Bcl 2 due to the mercury induced oxidative stress in albino rats.. The experimental rats were exposed to sub lethal concentration of mercuric chloride (1.25mg/kg) and the ameliorating effect of NaMSA was studied by using apoptotic protein markers Bax and caspase-3 and Bcl-2. The obtained results were analyzed using one way analysis of variance by the Duncan's Multiple comparison test to determine the level of significance (p) and p<0.05 was considered as statistically significant. Administration of mercuric chloride (1.25mg/kg) in the experimental rats increased the expression of Bax and caspase-3 and a decreased expression was noted in the Bcl-2 level compared with control bands significantly (p<0.05). On the other hand NaMSA (50mg/kg) and HgCl2 (1.25mg/kg) simultaneous administration did not bring any change in the protein expression of Bax, Caspase-3 and Bcl-2 levels compared with control rats. Hence, the membrane damage was protected, stopped the cell death and apoptosis. This could be due to the morin-5'-sulfonic acid sodium salt effective chelation action on the HgCl2 generated free radicals.

  2. Valproic Acid

    MedlinePlus

    Valproic acid is used alone or with other medications to treat certain types of seizures. Valproic acid is also used to treat mania (episodes of ... to relieve headaches that have already begun. Valproic acid is in a class of medications called anticonvulsants. ...

  3. Acid-catalytic decomposition of peracetic acid in the liquid phase

    SciTech Connect

    Kharchuk, V.G.; Kolenko, I.P.; Petrov, L.A.

    1985-12-01

    This paper elucidates the kinetic relationships of peracetic acid (PAA) decomposition in the presence of mineral acids and their heterogeneous analogs, polystyrene-di-vinylbenzene cation-exchangers, differing in physicochemical and morphological parameters. It is shown that the thermal decomposition of PAA in acetic acid is an acid-catalyzed reaction. The controlling step of the reaction is protonation of the substrate with formation of an active intermediate form. Sulfonated cation-exchangers are twice as effective as sulfuric acid in this process. Polystyrene-divinylbenzene sulfonated cation-exchangers can be used with success as acid catalysts in oxidation processes involving PAA, because of their high effectiveness, stability, and availability.

  4. Modified overbased sulfonates and phenates

    SciTech Connect

    Strukl, J.S.; Watson, R.W.

    1982-05-04

    Disclosed are compositions of matter and a method for their manufacture, and lubricating oil compositions containing such compositions. The compositions of matter comprise the reaction product of basic compound comprising overbased metal sulfonate, phenate, or mixtures thereof, with acidic compound comprising organic carboxylic acid, organic carboxylic acid anhydride, phosphoric acid, phosphoric acid ester, thiophosphoric acid ester , or mixtures thereof.

  5. Sorption of REE and TPE on sulfonated strong-acid cation exchanger KU-2 from multicomponent HNO{sub 3} solutions

    SciTech Connect

    Chuveleva, E.A.; Kharitonov, O.V.; Firsova, L.A.

    1995-05-01

    Sorption of rare earths (REE) from multicomponent systems is studied as a function of solution acidity (0.1-2.0 M) and temperature (20-70{degrees}C). The elution curves for REE and transplutonium-element (TPE) sorption pass through a maximum, the value of which increases with decreasing solution acidity. The selectivity order changes for Y. This phenomenon is explained. The separation coefficients Nd-M are determined for various [HNO{sub 3}]. In the range [H{sup +}] = 0.5-2.01 M, the separation coefficients become <1. The optimal conditions for REE and TPE sorption are determined.

  6. The Attenuation of Scutellariae radix Extract on Oxidative Stress for Colon Injury in Lipopolysaccharide-induced RAW264.7 Cell and 2,4,6-trinitrobenzene Sulfonic Acid-induced Ulcerative Colitis Rats

    PubMed Central

    Jin, Yu; Yang, Jun; Lin, Lianjie; Lin, Yan; Zheng, Changqing

    2016-01-01

    Background: Oxidative stress (OS) has been regarded as one of the major pathogeneses of ulcerative colitis (UC) through damaging colon. It has been shown that Scutellariae radix (SR) extract has a beneficial effect for the prevention and treatment of UC. Objective: The aim of this study was to investigate whether SR had a potential capacity on oxidant damage for colon injury both in vivo and in vitro. Materials and Methods: The 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to induce UC rats model while 1 μg/ml lipopolysaccharide (LPS) was for RAW264.7 cell damage. Disease activity index (DAI) was determined to response the severity of colitis. The myeloperoxidase (MPO) activity in rat colon was also estimated. The 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid assay was performed to evaluate the total antioxidant capacity of SR. Furthermore, the activity of glutathione peroxidase (GSH-PX), catalase (CAT), superoxide dismutase (SOD), and lipid peroxidation malondialdehyde (MDA) in cell supernatant and rat serum were detected by appropriate kits. In addition, an immunohistochemical assay was applied to examine transforming growth factor beta 1 (TGF-β1) protein expression in colon tissue. Results: The treatment with SR could significantly increase the activity of GSH-PX, CAT, and SOD associated with OS in LPS-induced RAW264.7 cell damage and TNBS-induced UC rats. However, the level of MDA was markedly reduced both in vitro and in vivo. Furthermore, SR significantly decreased DAI and reversed the increased MPO activity. Thus, SR could decrease the severity of acute TNBS-induced colitis in rats. Immunohistochemical assay showed that SR significantly downregulated TGF-β1 protein expression in colon tissue. Conclusion: Our data provided evidence to support this fact that SR attenuated OS in LPS-induced RAW264.7 cell and also in TNBS-induced UC rats. Thus, SR may be an interesting candidate drug for the management of UC. SUMMARY Scutellariae radix (SR

  7. Fatty acids - trans fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  8. Sulfonate-modified phenylboronic acid-rich nanoparticles as a novel mucoadhesive drug delivery system for vaginal administration of protein therapeutics: improved stability, mucin-dependent release and effective intravaginal placement.

    PubMed

    Li, ChunYan; Huang, ZhiGang; Liu, ZheShuo; Ci, LiQian; Liu, ZhePeng; Liu, Yu; Yan, XueYing; Lu, WeiYue

    Effective interaction between mucoadhesive drug delivery systems and mucin is the basis of effective local placement of drugs to play its therapeutic role after mucosal administration including vaginal use, which especially requires prolonged drug presence for the treatment of gynecological infectious diseases. Our previous report on phenylboronic acid-rich nanoparticles (PBNPs) demonstrated their strong interaction with mucin and mucin-sensitive release profiles of the model protein therapeutics interferon (IFN) in vitro, but their poor stability and obvious tendency to aggregate over time severely limited future application. In this study, sulfonate-modified PBNPs (PBNP-S) were designed as a stable mucoadhesive drug delivery system where the negative charges conferred by sulfonate groups prevented aggregation of nanoparticles and the phenylboronic acid groups ensured effective interaction with mucin over a wide pH range. Results suggested that PBNP-S were of spherical morphology with narrow size distribution (123.5 nm, polydispersity index 0.050), good stability over a wide pH range and 3-month storage and considerable in vitro mucoadhesion capability at vaginal pH as shown by mucin adsorption determination. IFN could be loaded to PBNP-S by physical adsorption with high encapsulation efficiency and released in a mucin-dependent manner in vitro. In vivo near-infrared fluorescent whole animal imaging and quantitative vaginal lavage followed by enzyme-linked immunosorbent assay (ELISA) assay of IFN demonstrated that PBNP-S could stay in the vagina and maintain intravaginal IFN level for much longer time than IFN solution (24 hours vs several hours) without obvious histological irritation to vaginal mucosa after vaginal administration to mice. In summary, good stability, easy loading and controllable release of protein therapeutics, in vitro and in vivo mucoadhesive properties and local safety of PBNP-S suggested it as a promising nanoscale mucoadhesive drug delivery

  9. Sulfonate-modified phenylboronic acid-rich nanoparticles as a novel mucoadhesive drug delivery system for vaginal administration of protein therapeutics: improved stability, mucin-dependent release and effective intravaginal placement

    PubMed Central

    Li, ChunYan; Huang, ZhiGang; Liu, ZheShuo; Ci, LiQian; Liu, ZhePeng; Liu, Yu; Yan, XueYing; Lu, WeiYue

    2016-01-01

    Effective interaction between mucoadhesive drug delivery systems and mucin is the basis of effective local placement of drugs to play its therapeutic role after mucosal administration including vaginal use, which especially requires prolonged drug presence for the treatment of gynecological infectious diseases. Our previous report on phenylboronic acid-rich nanoparticles (PBNPs) demonstrated their strong interaction with mucin and mucin-sensitive release profiles of the model protein therapeutics interferon (IFN) in vitro, but their poor stability and obvious tendency to aggregate over time severely limited future application. In this study, sulfonate-modified PBNPs (PBNP-S) were designed as a stable mucoadhesive drug delivery system where the negative charges conferred by sulfonate groups prevented aggregation of nanoparticles and the phenylboronic acid groups ensured effective interaction with mucin over a wide pH range. Results suggested that PBNP-S were of spherical morphology with narrow size distribution (123.5 nm, polydispersity index 0.050), good stability over a wide pH range and 3-month storage and considerable in vitro mucoadhesion capability at vaginal pH as shown by mucin adsorption determination. IFN could be loaded to PBNP-S by physical adsorption with high encapsulation efficiency and released in a mucin-dependent manner in vitro. In vivo near-infrared fluorescent whole animal imaging and quantitative vaginal lavage followed by enzyme-linked immunosorbent assay (ELISA) assay of IFN demonstrated that PBNP-S could stay in the vagina and maintain intravaginal IFN level for much longer time than IFN solution (24 hours vs several hours) without obvious histological irritation to vaginal mucosa after vaginal administration to mice. In summary, good stability, easy loading and controllable release of protein therapeutics, in vitro and in vivo mucoadhesive properties and local safety of PBNP-S suggested it as a promising nanoscale mucoadhesive drug delivery

  10. Evaluation of organic acids as fuel cell electrolytes

    SciTech Connect

    Ahmad, J.; Nguyen, T.H.; Foley, R.T.

    1981-11-01

    The electrochemical behavior of methanesulfonic acid, ethanesulfonic acid, and sulfoacetic acid as fuel cell electrolytes was studied in half-cell at various temperatures. The rate of the electro-oxidation of hydrogen at 115/degree/C was very high in methanesulfonic acid. The rate of the electro-oxidation of propane in all three acids was low even at 135/degree/C. Further, there is evidence for adsorption of these acids on the platinum electrode. It is concluded that anhydrous sulfonic acids are not good electrolytes; water solutions are required. Sulfonic acids containing unprotected carbon-hydrogen bonds are adsorbed on platinum and probably decompose during electrolysis. 9 refs.

  11. Developmental Toxicity of Perfluorinated Phosphonic Acids in Mice

    EPA Science Inventory

    Perfluorinated phosphonic acids (PFPAs) are a third member of the perfluoroalkyl acid (PFAA) family, and are structurally similar to the perfluoroalkyl sulfonates and perfluoroalkyl carboxylates. PFPAs are used primarily as a surfactant defoaming agent in pesticide production. Re...

  12. Developmental toxicity of perfluorononanoic acid in the mouse.

    EPA Science Inventory

    Toxicology Curriculum, University of North Carolina, Chapel Hill, NC Perfluorononanoic acid (PFNA) is a persistent environmental contaminant. Although its levels in the environment are lower than those of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA), its pre...

  13. 3D Anhydrous proton-transporting nanochannels formed by self-assembly of liquid crystals composed of a sulfobetaine and a sulfonic acid.

    PubMed

    Soberats, Bartolome; Yoshio, Masafumi; Ichikawa, Takahiro; Taguchi, Satomi; Ohno, Hiroyuki; Kato, Takashi

    2013-10-16

    Herein we describe anhydrous proton transportation through 3D interconnected pathways formed by self-assembled molecular complexes. A thermotropic bicontinuous cubic (Cub(bi)) phase has been successfully obtained by mixing a wedge-shaped sulfobetaine with benzenesulfonic acid in different ratios. These ionic complexes exhibit the Cub(bi) phase in a wide range of temperatures, while the single zwitterionic compound shows only a columnar hexagonal phase, and benzenesulfonic acid is nonmesomorphic. Anhydrous proton conduction on the order of 10(-4) S cm(-1) has been achieved for the mixture in the Cub(bi) phase over 100 °C, which can be useful for the development of new electrolytes for the next generation of fuel cells.

  14. Ion Exchange and Antibiofouling Properties of Poly(ether sulfone) Membranes Prepared by the Surface Immobilization of Brønsted Acidic Ionic Liquids via Double-Click Reactions.

    PubMed

    Yi, Zhuan; Liu, Cui-Jing; Zhu, Li-Ping; Xu, You-Yi

    2015-07-28

    Brønsted acidic ionic liquids (BAILs) are unique ionic liquids that display chemical structures similar to zwitterions, and they were typically used as solvents and catalysts. In this work, an imidazole-based BAIL monolayer was fabricated onto poly(ether sulfone) (PES) membranes via surface clicking reactions, and the multifunctionality, including ion exchange and biofouling resistance to proteins and bacteria, was demonstrated, which was believed to be one of few works in which BAIL had been considered to be a novel fouling resistance layer for porous membranes. The successful immobilization of the BAILs onto a membrane surface was confirmed by X-ray photoelectron spectroscopy analysis, contact angle measurement, and ζ potential determination. The results from Raman spectroscopy showed that, as a decisive step prior to zwitterion, the BAIL was deprotonated in aqueous solution, and biofouling resistance to proteins and bacteria was found. However, BAIL displayed ion exchange ability at lower pH, and surface hydrophilicity/hydrophobicity of membranes could be tuned on purpose. Our results have demonstrated that the BAIL grafted onto membranes will not only act as an antibiofouling barrier like zwitterions but also provide a platform for surface chemical tailoring by ion exchange, the property of which will become especially important in acidic solutions where the fouling resistance performances of zwitterions are greatly weakened.

  15. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  16. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications.

  17. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  18. Synthesis and characterization of binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) ions based on 4-aminotoluene-3-sulfonic acid

    NASA Astrophysics Data System (ADS)

    Faheim, Abeer A.; Abdou, Safaa N.; Abd El-Wahab, Zeinab H.

    2013-03-01

    Salicylidene (4-aminotoluene-3-sulfonic acid) Schiff base ligand H2L, and its binary and ternary Co(II), Ni(II), Cu(II) and Zn(II) complexes using 8-hydroxyquinoline (8-HOqu) and 2-aminopyridine (2-Ampy) as secondary ligands have been synthesised and characterized via elemental analysis, spectral data (IR, 1H NMR, mass and solid reflectance), molar conductance, magnetic moment, TG-DSC measurements and XRPD analysis. Correlation of all spectroscopic data suggest that H2L ligand acts as monoanionic terdentate ligand with ONO sites coordinating to the metal ions via deprotonated phenolic-O, azomethine-N and sulfonate-O while 2-Ampy behaves as a neutral monodentate ligand via amino group-N and 8-HOqu behaves as a monoanionic bidentate ligand through the ring-N and deprotonated phenolic-O. The thermal behavior of these complexes shows that the coordinated water molecules were eliminated from the complexes at relatively higher temperatures than the hydrated water and there are two routes in removal of coordinated water molecules. All complexes have mononuclear structure and the tetrahedral, square planar or an octahedral geometry have been proposed. The ligand and its complexes have been screened for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Candida albicans and Aspergillus fumigatus. Among the synthesised compounds, the binary and ternary Ni(II) complexes, (2, 8 and 10) and ternary Zn(II) complex, (12) were found to be very effective against Candida albicans and Bacillus subtilis than all other complexes with MICs of 2 and 8 μg/mL, respectively.

  19. Synthesis and characterization of binary and ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) ions based on 4-aminotoluene-3-sulfonic acid.

    PubMed

    Faheim, Abeer A; Abdou, Safaa N; Abd El-Wahab, Zeinab H

    2013-03-15

    Salicylidene (4-aminotoluene-3-sulfonic acid) Schiff base ligand H(2)L, and its binary and ternary Co(II), Ni(II), Cu(II) and Zn(II) complexes using 8-hydroxyquinoline (8-HOqu) and 2-aminopyridine (2-Ampy) as secondary ligands have been synthesised and characterized via elemental analysis, spectral data (IR, (1)H NMR, mass and solid reflectance), molar conductance, magnetic moment, TG-DSC measurements and XRPD analysis. Correlation of all spectroscopic data suggest that H(2)L ligand acts as monoanionic terdentate ligand with ONO sites coordinating to the metal ions via deprotonated phenolic-O, azomethine-N and sulfonate-O while 2-Ampy behaves as a neutral monodentate ligand via amino group-N and 8-HOqu behaves as a monoanionic bidentate ligand through the ring-N and deprotonated phenolic-O. The thermal behavior of these complexes shows that the coordinated water molecules were eliminated from the complexes at relatively higher temperatures than the hydrated water and there are two routes in removal of coordinated water molecules. All complexes have mononuclear structure and the tetrahedral, square planar or an octahedral geometry have been proposed. The ligand and its complexes have been screened for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Candida albicans and Aspergillus fumigatus. Among the synthesised compounds, the binary and ternary Ni(II) complexes, (2, 8 and 10) and ternary Zn(II) complex, (12) were found to be very effective against Candida albicans and Bacillus subtilis than all other complexes with MICs of 2 and 8 μg/mL, respectively.

  20. Acid fog

    SciTech Connect

    Hileman, B.

    1983-03-01

    Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

  1. Changes in morphometry and association between whole-body fatty acids and steroid hormone profiles in relation to bioaccumulation patterns in salmon larvae exposed to perfluorooctane sulfonic or perfluorooctane carboxylic acids.

    PubMed

    Arukwe, Augustine; Cangialosi, Maria V; Letcher, Robert J; Rocha, Eduardo; Mortensen, Anne S

    2013-04-15

    In the present study, we have used salmon embryos whose continuous exposure to waterborne PFOA or PFOS at 100 μg/L started as freshly fertilized eggs, and lasted for a total of 52 days. PFOS and PFOA were dissolved in methanol (carrier vehicle) whose concentration never exceeded 0.01% of total tank volume. Samples were collected at day 21, 28, 35, 52, 49 and 56 after the start of the exposure. Note that days 49 and 56 represent end of exposure and 1 week after a recovery period, respectively. Tissue bioaccumulations were determined by HPLC/MS/MS, steroid hormones, fatty acids (FAs) and lipids were determined by GC-MS, while mRNA expression levels of genes were determined by qPCR in whole body homogenate. We observed that PFOS and PFOA showed a steady increase in whole body burden during the exposure period, with a slight decrease after the recovery period. Calculated somatic indexes showed that PFOA produced increases in heart-, thymus-, liver- and kidney somatic indexes (HSI, TSI, LSI and KSI). PFOA and PFOS exposure produced significant decreases in whole body dehydroepiandrosterone (DHEA), estrone and testosterone at sampling day 21 and a strong increase of cortisol and cholesterol at the end of recovery period (day 56). PFOA and PFOS effects differed with DHEA and estrone. While PFOS decreased DHEA levels, PFOA produced an increase at day 49, and while PFOS decreased estrone, PFOA produced a slight increase at day 56. We observed changes in FA composition that predominantly involved increases in FA methyl esters (FAMEs), mono- and poly-unsaturated FA (MUFA and PUFA) and a decrease in n-3/n-6 PUFA ratio by both PFOA and PFOS. Particularly, an increase in - pentadecenoic MUFA (15:1), two n-3 PUFAs α-linolenic acid [ALA: 18:3 n3] and eicosapentaenoic acid [EPA: 20:5 n-3] and n-6 PUFA: arachidonic acid [ARA: 20:4 n6], docosapentaenoic acid (DPA) by PFOA and PFOS were observed. These effects were associated with changes in mRNA expression of FA elongase (FAE), Δ5

  2. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  3. Acid Rain

    MedlinePlus

    ... EPA Is Doing Acid Rain Program Cross-State Air Pollution Rule Progress Reports Educational Resources Kid's Site for ... Monitoring National Atmospheric Deposition Program (NADP) Exit Interstate Air Pollution Transport Contact Us to ask a question, provide ...

  4. Folic Acid

    MedlinePlus

    ... folic acid can hide signs that you lack vitamin B12, which can cause nerve damage. 10 Do I ... Rosenberg, I.H., et al. (2007). Folate and vitamin B12 status in relation to anemia, macrocytosis and cognitive ...

  5. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  6. Toxicogenomic profiling of perfluorononanoic acid in wild-type and PPARa-null mice

    EPA Science Inventory

    Perfluorononanoic acid (PFNA) is a ubiquitous environmental contaminant and a developmental toxicant in laboratory animals. Like other perfluoroalkyl acids (PFAAs) such as perfluorooctane sulfonate (PFOA) and perfluoroalkyl acid (PFOS), PFNA is a known activator ofperoxisome prol...

  7. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  8. Developmental Toxicity of Perfluoronanoic Acid in Mice

    EPA Science Inventory

    Perfluorononanoic acid (PFNA) is a ubiquitous and persistent environmental contaminant. Although its levels in the environment and in humans are lower than those of perfluorooctane sulfonate(PFOS) or perfluorooctanoic acid (PFOA), a steady trend of increases in the general popula...

  9. Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

    DOEpatents

    Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

    2016-06-07

    An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

  10. Microbial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.

    PubMed Central

    Zürrer, D; Cook, A M; Leisinger, T

    1987-01-01

    Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein. A Pseudomonas sp., an Arthrobacter sp., and an unidentified bacterium were examined. Each desulfonated at least 16 aromatic compounds, none of which served as a carbon source. Pseudomonas sp. strain S-313 converted 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, benzenesulfonic acid, and 3-aminobenzenesulfonic acid to 1-naphthol, 2-naphthol, 5-amino-1-naphthol, phenol, and 3-aminophenol, respectively. Experiments with 18O2 showed that the hydroxyl group was derived from molecular oxygen. PMID:3662502

  11. β-Casein hydrolysate generated by the cell envelope-associated proteinase of Lactobacillus delbrueckii ssp. lactis CRL 581 protects against trinitrobenzene sulfonic acid-induced colitis in mice.

    PubMed

    Espeche Turbay, M B; de Moreno de LeBlanc, A; Perdigón, G; Savoy de Giori, G; Hebert, E M

    2012-03-01

    Lactobacillus delbrueckii ssp. lactis CRL 581, a thermophilic lactic acid bacterium used as a starter culture for the manufacture of several fermented dairy products, possesses an efficient proteolytic system that is able to release a series of potentially bioactive peptides (i.e., antihypertensive and phosphopeptides) from α- and β-caseins. Considering the potential beneficial health effects of the peptides released by L. delbrueckii ssp. lactis CRL 581 from milk proteins, the aim of this work was to analyze the anti-mutagenic and anti-inflammatory properties of the casein hydrolysates generated by the cell envelope-associated proteinase of this bacterium. The ability of α- and β-casein hydrolysates to suppress the mutagenesis of a direct-acting mutagen 4-nitroquinoline-N-oxide on Salmonella typhimurium TA 98 and TA 100 increased concomitantly with the time of casein hydrolysis. The anti-inflammatory effect of the β-casein hydrolysate was evaluated using a trinitrobenzene sulfonic acid (TNBS)-induced Crohn's disease murine model. The hydrolysate was administered to mice 10 d before the intrarectal inoculation of TNBS. The mice that received β-casein hydrolysate previously to TNBS showed decreased mortality rates, faster recovery of initial body weight loss, less microbial translocation to the liver, decreased β-glucuronidase and myeloperoxidase activities in the gut, and decreased colonic macroscopic and microscopic damage compared with the animals that did not receive this hydrolysate. In addition, β-casein hydrolysate exerted a beneficial effect on acute intestinal inflammation by increased interleukin 10 and decreased IFN-γ production in the gut. Our findings are consistent with the health-promoting attributes of the milk products fermented by L. delbrueckii ssp. lactis CRL 581 and open up new opportunities for developing novel functional foods.

  12. Determination of perfluorooctanoic acid and perfluorooctane sulfonate in cooking oil and pig adipose tissue using reversed-phase liquid-liquid extraction followed by high performance liquid chromatography tandem mass spectrometry.

    PubMed

    Tang, Caiming; Tan, Jianhua; Wang, Chunwei; Peng, Xianzhi

    2014-05-09

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are two perfluorinated compounds (PFCs) ubiquitously present in the environment, which could pose potential adverse effects on human health. Contamination and presence of PFOA and PFOS should be eliminated or rigidly restricted in food stuffs such as cooking oils and lard (from pig adipose tissue). This work describes a rapid, simple, reliable and sensitive method for quantitative analysis of PFOA and PFOS in cooking oils and pig adipose tissue with liquid chromatography tandem mass spectrometry (LC-MS/MS). The pretreatment mainly included a one-step reversed-phase liquid-liquid extraction using the mixture of basified water/methanol as the aqueous system, and dichloromethane (DCM) as the non-polar system. PFOA and PFOS can be successfully separated from the two lipid-rich matrices, i.e., cooking oil and adipose tissue, and extracted into the aqueous system, and then directly analyzed with LC-MS/MS. This method was validated in terms of accuracy (both intra- and inter-batch), precision, recovery, linearity, sensitivity and applicability. The intra-batch accuracies for PFOA and PFOS in cooking oil samples were within 93.9-101.9% with relative standard deviation (RSD) no more than 10.9%, and the inter-batch accuracies were 91.2-96.2% with RSD not exceeding 10.0%. The intra-batch accuracies of the analytes in pig adipose tissue samples were 102.9-113.0% with RSD of 8.8-13.1%. And the quantification ranges of PFOA and PFOS were 0.01-25ng/mL. This method has been applied to the analysis of PFOA and PFOS in real samples collected from local markets in Guangzhou, China.

  13. Application of the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay to a flow injection system for the evaluation of antioxidant activity of some pure compounds and beverages.

    PubMed

    Pellegrini, Nicoletta; Del Rio, Daniele; Colombi, Barbara; Bianchi, Marta; Brighenti, Furio

    2003-01-01

    The 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*)(+)) assay was adapted to a flow injection (FI) system to obtain a sensitive and rapid technique for the monitoring of antioxidant activity of pure compounds and complex matrixes, such as beverages and food extracts. The FI system includes a HPLC pump that flows the mobile phase (a solution of ABTS(*)(+) in ethanol) through a 20 microL loop injector, a single bead string reactor filled with acid-washed silanized beads, a delay coil and a photodiode array UV-visible detector. The technique was very sensitive, with limits of detection and of quantification of 4.14 and 9.29 micromol of Trolox/L, respectively, and demonstrated high repeatability and reproducibility. The proposed technique was then applied to the evaluation of the antioxidant activity of some pure compounds, demonstrating good agreement with published data obtained by the original spectrophotometric ABTS(*)(+) assay. Finally, the total antioxidant activity of 10 beverages was determined by both the proposed and the original method. The values ranged from 0.09 mmol L(-)(1) for cola to 49.24 mmol L(-)(1) for espresso coffee and did not result significantly different from those obtained by the original spectrophotometric ABTS(*)(+) assay (Student's paired t-test: t = 1.4074, p = 0.1929). In conclusion, the proposed FI technique seems suitable for the direct, rapid and reliable monitoring of total antioxidant activity of pure compounds and beverages and, due to the ability to operate in continuous, it allows the analysis of about 30 samples h(-)(1) making the assay particularly suitable for large screening of total antioxidant activity in food samples.

  14. Congener-specific numbering systems for the environmentally relevant C4 through C8 perfluorinated homologue groups of alkyl sulfonates, carboxylates, telomer alcohols, olefins, and acids, and their derivatives.

    PubMed

    Rayne, Sierra; Forest, Kaya; Friesen, Ken J

    2008-10-01

    We introduce a congener-specific numbering system for the C4 through C8 perfluorinated homologue groups of alkyl sulfonates, carboxylates, telomer alcohols, olefins, and acids, and their derivatives. Increasing length of the carbon chain beyond C3 leads to a corresponding rapid increase in the number of potential isomers (C4 = 4, C5 = 8, C6 = 17, C7 = 39, and C8 = 89 congeners). There is a need for clear and unambiguous chemical shorthand to ensure accuracy and consistency in the future perfluorinated alkyl substance (PFA) literature, and to correct previous misconceptions that may have restricted research efforts into developing full-congener PFA analysis. If adopted by the research community, introduction of a numbering system at this relatively early stage of investigations into the congener-specific analysis, environmental behavior, and toxicology of PFAs would not require an arduous and difficult reassignment of historical structures and naming conventions presented in the prior art. Many PFA congeners are chiral, necessitating a consideration of their enantiospecific environmental behavior and toxicology.

  15. Carryover of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from soil to plant and distribution to the different plant compartments studied in cultures of carrots (Daucus carota ssp. Sativus), potatoes (Solanum tuberosum), and cucumbers (Cucumis Sativus).

    PubMed

    Lechner, Mareike; Knapp, Holger

    2011-10-26

    A vegetation study was carried out to investigate the carryover of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) from soil mixed with contaminated sewage sludge to potato, carrot, and cucumber plants. Analysis was done by liquid-extraction using acetonitrile with dispersive SPE cleanup and subsequent HPLC-MS/MS. In order to assess the transfer potential from soil, transfer factors (TF) were calculated for the different plant compartments: TF = [PFC](plant (wet substance))/[PFC](soil (dry weight)). The highest TF were found for the vegetative plant compartments with average values for PFOS below those for PFOA: cucumber, 0.17 (PFOS), 0.88 (PFOA); potato, 0.36 (PFOS), 0.40 (PFOA); carrot, 0.38 (PFOS), 0.53 (PFOA). Transfer of PFOA and PFOS into potato peelings (average values of TF: PFOA 0.03, PFOS 0.04) exceeded the carryover to the peeled tubers (PFOA 0.01, PFOS < 0.01). In carrots, this difference did not occur (average values of TF: PFOA 0.04, PFOS 0.04). Transfer of PFOS into the unpeeled cucumbers was low and comparable to that of peeled potatoes (TF < 0.01). For PFOA, it was higher (TF: 0.03).

  16. Structural insights into 2,2'-azino-Bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-mediated degradation of reactive blue 21 by engineered Cyathus bulleri Laccase and characterization of degradation products.

    PubMed

    Kenzom, T; Srivastava, P; Mishra, S

    2014-12-01

    Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)]. This laccase was engineered to degrade effectively reactive blue 21 (RB21), a phthalocyanine dye reported to be decolorized only by peroxidases. The 816-bp segment (toward the C terminus) of the lcc gene was subjected to random mutagenesis and enzyme variants (Lcc35, Lcc61, and Lcc62) were selected based on increased ABTS oxidizing ability. Around 78 to 95% decolorization of RB21 was observed with the ABTS-supplemented Lcc variants in 30 min. Analysis of the degradation products by mass spectrometry indicated the formation of several low-molecular-weight compounds. Mapping the mutations on the modeled structure implicated residues both near and far from the T1 Cu site that affected the catalytic efficiency of the mutant enzymes on ABTS and, in turn, the rate of oxidation of RB21. Several inactive clones were also mapped. The importance of geometry as well as electronic changes on the reactivity of laccases was indicated.

  17. Structural Insights into 2,2′-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS)-Mediated Degradation of Reactive Blue 21 by Engineered Cyathus bulleri Laccase and Characterization of Degradation Products

    PubMed Central

    Kenzom, T.; Srivastava, P.

    2014-01-01

    Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)]. This laccase was engineered to degrade effectively reactive blue 21 (RB21), a phthalocyanine dye reported to be decolorized only by peroxidases. The 816-bp segment (toward the C terminus) of the lcc gene was subjected to random mutagenesis and enzyme variants (Lcc35, Lcc61, and Lcc62) were selected based on increased ABTS oxidizing ability. Around 78 to 95% decolorization of RB21 was observed with the ABTS-supplemented Lcc variants in 30 min. Analysis of the degradation products by mass spectrometry indicated the formation of several low-molecular-weight compounds. Mapping the mutations on the modeled structure implicated residues both near and far from the T1 Cu site that affected the catalytic efficiency of the mutant enzymes on ABTS and, in turn, the rate of oxidation of RB21. Several inactive clones were also mapped. The importance of geometry as well as electronic changes on the reactivity of laccases was indicated. PMID:25261507

  18. Determination of alachlor and its sulfonic acid metabolite in water by solid-phase extraction and enzyme-linked immunosorbent assay

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.; Pomes, M.L.

    1994-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were combined for the trace analysis of the herbicide alachlor and its major soil metabolite, ethanesulfonic acid (ESA). The anti-alachlor antibody cross-reacted with ESA, which produced false-positive detections of alachlor in water samples by immunoassay screens. Alachlor and ESA were isolated from water by SPE on a C18 resin and eluted sequentially with ethyl acetate and methanol. Alachlor is soluble in ethyl acetate while the anionic ESA is not. Thus ESA remained adsorbed on the C18 resin and was eluted later with methanol. The combination of SPE with ELISA effectivety separated and quantified both alachlor and ESA using the same antibody for two ELISA methods. The general method may have applicability for the separation of other herbicides and their ionic metabolites. The SPE-ELISA method has a, detection limit of 0.01 ??g/L for alachlor and 0.05 ??g/L for ESA, with a precision of ?? 10%. Analyses of surface and ground water samples were confirmed by gas chromatography/mass spectrometry and high-performance liquid chromatography with photodiode-array detection. Results showed widespread occurrence of ESA in surface and ground water of the midwestern United States, with concentrations ranging from 10 ??g/L.

  19. New core@shell nanogel based 2-acrylamido-2-methyl-1-propane sulfonic acid for preconcentration of Pb(II) from various water samples

    NASA Astrophysics Data System (ADS)

    Shoueir, Kamel Rizq; Akl, Magda Ali; Sarhan, Ali Ali; Atta, Ayman Mohamdy

    2016-12-01

    Poly(vinyl alcohol) core coated with poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-N-isopropylacrylamide) shell to produce well-define PVA@P(AMPS-co-NIPAm) core shell nanogels with a core of 25 ± 0.5 nm and shell of 5 ± 0.5 nm. The synthetic approach was produced by a surfactant free emulsion polymerization (SFEP). The specific area was found to be 1685.8 m2/g. The nanogels were studied in a batch adsorption for removal of Pb(II) ions and characterized by SEM, TEM, TGA and BET measurements. The results showed that the adsorption equilibrium data fitted the Langmuir isotherm and the kinetic studies are well described by the pseudo-second-order kinetic model. The Pb(II) maximum adsorption was 510.2 (mg/g) for PVA@P(90AMPS-co-10NIPAm) (wt.: wt%). The PVA@P(AMPS-co-NIPAm) nanogels were applied for extracting of Pb(II) in real different environmental water samples successfully with high recoveries reaches 104.4%.

  20. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1993-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  1. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.; Dietrich, W.E.; Sposito, Garrison

    1997-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  2. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  3. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 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 E

  4. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    EPA 635 / R - 03 / 007 www.epa.gov / iris TOXICOLOGICAL REVIEW OF DICHLOROACETIC ACID ( CAS No . 79 - 43 - 6 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) August 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been revi

  5. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 09 / 003F www.epa.gov / iris TOXICOLOGICAL REVIEW OF TRICHLOROACETIC ACID ( CAS No . 76 - 03 - 9 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2011 U.S . Environmental Protection Agency Washington , DC ii DISCLAIMER This document has

  6. Acid rain

    SciTech Connect

    Not Available

    1984-06-01

    An overview is presented of acid rain and the problems it causes to the environment worldwide. The acidification of lakes and streams is having a dramatic effect on aquatic life. Aluminum, present in virtually all forest soils, leaches out readily under acid conditions and interferes with the gills of all fish, some more seriously than others. There is evidence of major damage to forests in European countries. In the US, the most severe forest damage appears to be in New England, New York's Adirondacks, and the central Appalachians. This small region is part of a larger area of the Northeast and Canada that appears to have more acid rainfall than the rest of the country. It is downwind from major coal burning states, which produce about one quarter of US SO/sub 2/ emissions and one sixth of nitrogen oxide emissions. Uncertainties exist over the causes of forest damage and more research is needed before advocating expensive programs to reduce rain acidity. The President's current budget seeks an expansion of research funds from the current $30 million per year to $120 million.

  7. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 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 Effec

  8. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 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 Effect

  9. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 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 Eff

  10. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 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

  11. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 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 Hazard Assessments for Noncarcinogenic Eff

  12. Role of voltage gated Ca2+ channels in rat visceral hypersensitivity change induced by 2,4,6-trinitrobenzene sulfonic acid

    PubMed Central

    2013-01-01

    Background Visceral pain is common symptom involved in many gastrointestinal disorders such as inflammatory bowel disease. The underlying molecular mechanisms remain elusive. We investigated the molecular mechanisms and the role for voltage gated calcium channel (VGCC) in the pathogenesis in a rat model of 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced visceral inflammatory hypersensitivity. Results Using Agilent cDNA arrays, we found 172 genes changed significantly in dorsal root ganglia (DRG) of TNBS treated rats. Among these changed genes, Cav1.2 and Cav2.3 were significantly up-regulated. Then the RT-PCR and Western blot further confirmed the up-regulation of Cav1.2 and Cav2.3. The whole cell patch clamp recording of acutely dissociated colonic specific DRG neurons showed that the peak IBa density was significantly increased in colonic neurons of TNBS treated rats compared with control rats (−127.82 ± 20.82 pA/pF Vs −91.67 ± 19.02 pA/pF, n = 9, *P < 0.05). To distinguish the different type of calcium currents with the corresponding selective channel blockers, we found that L-type (−38.56 ± 3.97 pA/pF Vs −25.75 ± 3.35 pA/pF, n = 9, * P < 0.05) and R-type (−13.31 ± 1.36 pA/pF Vs −8.60 ± 1.25 pA/pF, n = 9, * P < 0.05) calcium current density were significantly increased in colonic DRG neurons of TNBS treated rats compared with control rats. In addition, pharmacological blockade with L-type antagonist (nimodipine) and R-type antagonist (SNX-482) with intrathecal injection attenuates visceral pain in TNBS induced inflammatory visceral hypersensitivity. Conclusion Cav1.2 and Cav2.3 in colonic primary sensory neurons play an important role in visceral inflammatory hyperalgesia, which maybe the potential therapeutic targets. PMID:23537331

  13. Azelaic acid.

    PubMed

    Nazzaro-Porro, M

    1987-12-01

    This review is an update on the literature accumulated over the past 10 years following the original observation that azelaic acid, a naturally occurring and nontoxic C9 dicarboxylic acid, possesses significant biologic properties and a potential as a therapeutic agent. These studies have shown that azelaic acid is a reversible inhibitor of tyrosinase and other oxidoreductases in vitro and that it inhibits mitochondrial respiration. It can also inhibit anaerobic glycolysis. Both in vitro and in vivo it has an antimicrobial effect on both aerobic and anaerobic (Propionibacterium acnes) microorganisms. In tissue culture it exerts a dose- and time-dependent cytotoxic effect on malignant melanocytes, associated with mitochondrial damage and inhibition of deoxyribonucleic acid (DNA) synthesis. Tumoral cell lines not containing tyrosinase are equally affected. Normal cells in culture exposed to the same concentrations of the diacid that are toxic for tumoral cells are in general not damaged. Radioactive azelaic acid has been shown to penetrate tumoral cells at a higher level than normal cells of the corresponding line. Topically applied (a 20% cream), it has been shown to be of therapeutic value in skin disorders of different etiologies. Its beneficial effect on various forms of acne (comedogenic, papulopustular, nodulocystic) has been clearly demonstrated. Particularly important is its action on abnormal melanocytes, which has led to the possibility of obtaining good results on melasma and highly durable therapeutic responses on lentigo maligna. It is also capable of causing regression of cutaneous malignant melanoma, but its role in melanoma therapy remains to be investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Effects of elevated dissolved carbon dioxide and perfluorooctane sulfonic acid, given singly and in combination, on steroidogenic and biotransformation pathways of Atlantic cod.

    PubMed

    Preus-Olsen, Gunnhild; Olufsen, Marianne O; Pedersen, Sindre Andre; Letcher, Robert J; Arukwe, Augustine

    2014-10-01

    grouping of individual scores according to the exposure scenarios at day 6 and 9. Overall, the PCA analysis produced a unique clustering of variables that signifies a positive correlation between exposure to high PFOS concentration and mRNA expression of E2 responsive genes. Notably, this pattern was not evident for individuals exposed to PFOS concentrations in combination with elevated CO2 scenarios. To our knowledge, the present study is the first of its kind, to evaluate such effects using combined exposure to a perfluoroalkyl sulfonate and elevated levels of CO2 saturation, representative of future oceanic climate change, in any fish species or lower vertebrate.

  15. Hydroxycarboxylic acids and salts

    DOEpatents

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  16. Ferromagnetic Conducting Lignosulfonic Acid-doped Polyaniline Nanocomposites

    NASA Technical Reports Server (NTRS)

    Viswansthan, Tito (Inventor); Berry, Brian (Inventor)

    2004-01-01

    A conductive ferromagnetic composition of matter comprising sulfonated lignin or a sulfonated polyflavonoid, or derivatives thereof, and ferromagnetic iron oxide particles is disclosed. Among the uses of the composition is to shield electromagnetic radiation. The ferromagnetic iron oxide particles of the composition are surprisingly stable to acid, and are easily and inexpensively formed from iron cations in solution.

  17. Acidic domains around nucleic acids.

    PubMed Central

    Lamm, G; Pack, G R

    1990-01-01

    The hydrogen ion concentration in the vicinity of DNA was mapped out within the Poisson-Boltzmann approximation. Experimental conditions were modeled by assuming Na-DNA to be solvated in a buffer solution containing 45 mM Tris and 3 mM Mg cations at pH 7.5. Three regions of high H+ concentration (greater than 10 microM) are predicted: one throughout the minor groove of DNA and two localized in the major groove near N7 of guanine and C5 of cytosine for a G.C base pair. These acidic domains correlate well with the observed covalent binding sites of benzo[a]pyrene epoxide (N2 of guanine) and of aflatoxin B1 epoxide (N7 of guanine), chemical carcinogens that presumably undergo acid catalysis to form highly reactive carbocations that ultimately bind to DNA. It is suggested that these regions of high H+ concentration may also be of concern in understanding interactions involving proteins and noncarcinogenic molecules with or near nucleic acids. PMID:2123348

  18. Perfluoroalkyl acids and related chemistries Toxicokinetics and modes of action

    EPA Science Inventory

    The perfluoroalkyl acid salts (both carboxylates and sulfonates, hereafter designated as PFAAs) and their derivatives are important chemicals that have numerous consumer and industrial applications. However, recent discoveries that some of these compounds have global distribution...

  19. Acid-functionalized nanoparticles for biomass hydrolysis

    NASA Astrophysics Data System (ADS)

    Pena Duque, Leidy Eugenia

    Cellulosic ethanol is a renewable source of energy. Lignocellulosic biomass is a complex material composed mainly of cellulose, hemicellulose, and lignin. Biomass pretreatment is a required step to make sugar polymers liable to hydrolysis. Mineral acids are commonly used for biomass pretreatment. Using acid catalysts that can be recovered and reused could make the process economically more attractive. The overall goal of this dissertation is the development of a recyclable nanocatalyst for the hydrolysis of biomass sugars. Cobalt iron oxide nanoparticles (CoFe2O4) were synthesized to provide a magnetic core that could be separated from reaction using a magnetic field and modified to carry acid functional groups. X-ray diffraction (XRD) confirmed the crystal structure was that of cobalt spinel ferrite. CoFe2O4 were covered with silica which served as linker for the acid functions. Silica-coated nanoparticles were functionalized with three different acid functions: perfluoropropyl-sulfonic acid, carboxylic acid, and propyl-sulfonic acid. Transmission electron microscope (TEM) images were analyzed to obtain particle size distributions of the nanoparticles. Total carbon, nitrogen, and sulfur were quantified using an elemental analyzer. Fourier transform infra-red spectra confirmed the presence of sulfonic and carboxylic acid functions and ion-exchange titrations accounted for the total amount of catalytic acid sites per nanoparticle mass. These nanoparticles were evaluated for their performance to hydrolyze the beta-1,4 glycosidic bond of the cellobiose molecule. Propyl-sulfonic (PS) and perfluoropropyl-sulfonic (PFS) acid functionalized nanoparticles catalyzed the hydrolysis of cellobiose significantly better than the control. PS and PFS were also evaluated for their capacity to solubilize wheat straw hemicelluloses and performed better than the control. Although PFS nanoparticles were stronger acid catalysts, the acid functions leached out of the nanoparticle during

  20. Folic Acid and Pregnancy

    MedlinePlus

    ... Feeding Your 1- to 2-Year-Old Folic Acid and Pregnancy KidsHealth > For Parents > Folic Acid and ... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ...

  1. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  2. New Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...

  3. New bioactive fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to the new compounds, 7,10-dihydroxy-8(E)-octad...

  4. Effects of Perfluorinated Phosphonic Acid Exposure during pregnancy in the mouse

    EPA Science Inventory

    Perfluorinated phosphonic acids (PFPAs) are a member of the perfluoroalkyl acid (PFAA) family, and are structurally similar to the perfluoroalkyl sulfonates and perfluoroalkyl carboxylates. These chemicals have recently been detected in the environment, particularly in surface wa...

  5. Exposure to Perfluorononanoic acid during pregnancy: Evaluations of rat and mice model

    EPA Science Inventory

    Perfluorononanoic acid (PFNA) is a persistent environmental contaminant. Although its levels in the environment are lower than those of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA), its presence in humans is rising and is of concern. Previous studies have in...

  6. Preliminary assessment of developmental toxicity of Perfluorinated Phosphonic Acid in mice

    EPA Science Inventory

    Perfluorinated phosphonic acids (PFPAs) are a third member of the perfluoroalkyl acid (PFAA) family, and are structurally similar to the perfluoroalkyl sulfonates and perfluoroalkyl carboxylates. These emerging chemicals have recently been detected in the environment, particularl...

  7. Acid rain

    SciTech Connect

    Boyle, R.H.; Boyle, R.A.

    1983-01-01

    Acid rain, says Boyle is a chemical leprosy eating into the face of North America and Europe, perhaps the major ecological problem of our time. Boyle describes the causes and scope of the phenomenon; the effects on man, wildlife, water, and our cultural heritage. He probes the delays of politicians and the frequent self-serving arguments advanced by industry in the face of what scientists have proved. The solutions he offers are to strengthen the Clean Air Act and require emission reductions that can be accomplished by establishing emission standards on a regional or bubble basis, burn low-sulfur coal, install scrubbers at critical plants, and invest in alternative energy sources. 73 references, 1 figure.

  8. Current Understanding of Perfluoroalkyl Acid Toxicology

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-14 carbons in length) and an anionic head group (sulfonate, carboxylate or phosphonate). These compounds have excellent surface-tension reducing properties and hav...

  9. Sulfonated guaianolides from Saussurea lappa.

    PubMed

    Wang, Fei; Xie, Zheng-Hong; Gao, Yuan; Xu, Yao; Cheng, Xue-Lian; Liu, Ji-Kai

    2008-06-01

    Two new guaiane-type sesquiterpene lactones with an unusual sulfonic acid group, sulfocostunolide A (1) and sulfocostunolide B (2), were isolated from the roots of Saussurea lappa. Their structures were elucidated on the basis of extensive spectroscopic analysis.

  10. Computational study on the acidic constants of chiral Brønsted acids in dimethyl sulfoxide.

    PubMed

    Yang, Chen; Xue, Xiao-Song; Li, Xin; Cheng, Jin-Pei

    2014-05-16

    The pK(a) values of a series of chiral Brønsted acids, including N-triflylphosphoramides, bis(sulfonyl)imides, bis(sulfuryl)imides, dicarboxylic acids, sulfonic acids, and N-phosphinyl phosphoramides, were predicted by using the SMD/M06-2x/6-311++G(2df,2p)//B3LYP/6-31+G(d) method in DMSO. The results revealed that the calculated pKa values ranged from -9.06 to 12.18 for different types of acids. The influence of acidic strength on reactivity and stereoselectivity was discussed using the calculated acidity data. Given that the choice of catalyst with appropriate acidity is the primary condition, several new catalyst candidates were designed by calculating corresponding pK(a) values of parent acids.

  11. Perfluoroalkyl acids: recent research highlights | Science ...

    EPA Pesticide Factsheets

    Perfluorinated compounds are organic chemicals in which all hydrogen molecules of the carbon-chain are substituted by fluorine molecules. Generally, there are two types of perfluorinated compounds, the perfluoroalkanes that are primarily used clinically for oxygenation and respiratory ventilation, and the perfluoroalkyl acids (PFAAs). Environmentally relevant PFAAs are a family of about 30 chemicals that consist of a carbon backbone typically 4-14 molecules in length and a charged functional group composed of either sulfonates, carboxylates or phosphonates (and to a lesser extent, phosphinates). While many (>100) derivatives ofPFAAs (such as alcohols, amides, esters and acids) are used for industrial and consumer applications, they can be degraded or metabolized to PFAAs as end-stage products. Thus, PFAAs, rather than their intermediates or derivatives, have drawn the most public attention and research interest. The most widely known PFAAs are the eight-carbon (C8) sulfonate (perfluorooctane sulfonate, PFOS) and carboxylate (perfluorooctanoic acid, PFOA), although the C4 (perfluorobutane) and C6 (perfluorohexane) sulfonates, as well as the C4, C6 and C9 (perfluorononanoic) carboxylates have also been used in commerce. The perfluoroalkyl phosphonates (PFPAs) are fairly new entities for this class ofchemicals. They are typically used as leveling and wetting agents, and defoaming additives in the production of pesticides. They were considered biologically inert by

  12. Ion exclusion chromatography of aromatic acids.

    PubMed

    Mansour, Fotouh R; Kirkpatrick, Christine L; Danielson, Neil D

    2013-08-01

    The determination of aromatic acids by ion exclusion chromatography is challenging due to peak tailing and the long retention time of hydrophobic solutes. This review discusses the retention mechanisms and the factors affecting retention, eluents and detection methods used in ion exclusion chromatography of aromatic acids such as mono-, di-, tri- and tetra-carboxylic acids, amino acids, sulfonates and phenol. In addition, the different approaches used to improve the chromatographic separation of these compounds are also discussed. These approaches include introducing an internal gradient of the ionic strength, using vacancy ion exclusion chromatography, employing a hydrophilic cation exchange resin or adding a modifier such as heptanol to the dilute sulfuric acid mobile phase. The applications of these methods in the analysis of aromatic acids are provided with a table summarizing the stationary phases, the mobile phases and the detection methods.

  13. Process for sulfonation of gas oils

    SciTech Connect

    Berg, R. C.

    1980-12-23

    A process for the production of oil-soluble sulfonates from a gas oil such as a vacuum gas oil. Water-soluble sulfonic acids are separated from the effluent of the sulfonation zone, and the remainder of the effluent is then passed through a saponification zone to produce oil-soluble sulfonates which are then recovered. The remaining hydrocarbons are fractionated, with the resultant heavy fraction being passed through a reforming zone to produce additional aromatics which are then recycled to the sulfonation zone.

  14. [Teichoic acids from lactic acid bacteria].

    PubMed

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  15. Organic acids tunably catalyze carbonic acid decomposition.

    PubMed

    Kumar, Manoj; Busch, Daryle H; Subramaniam, Bala; Thompson, Ward H

    2014-07-10

    Density functional theory calculations predict that the gas-phase decomposition of carbonic acid, a high-energy, 1,3-hydrogen atom transfer reaction, can be catalyzed by a monocarboxylic acid or a dicarboxylic acid, including carbonic acid itself. Carboxylic acids are found to be more effective catalysts than water. Among the carboxylic acids, the monocarboxylic acids outperform the dicarboxylic ones wherein the presence of an intramolecular hydrogen bond hampers the hydrogen transfer. Further, the calculations reveal a direct correlation between the catalytic activity of a monocarboxylic acid and its pKa, in contrast to prior assumptions about carboxylic-acid-catalyzed hydrogen-transfer reactions. The catalytic efficacy of a dicarboxylic acid, on the other hand, is significantly affected by the strength of an intramolecular hydrogen bond. Transition-state theory estimates indicate that effective rate constants for the acid-catalyzed decomposition are four orders-of-magnitude larger than those for the water-catalyzed reaction. These results offer new insights into the determinants of general acid catalysis with potentially broad implications.

  16. Plasma amino acids

    MedlinePlus

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  17. Uric acid - urine

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003616.htm Uric acid urine test To use the sharing features on this page, please enable JavaScript. The uric acid urine test measures the level of uric acid ...

  18. Facts about Folic Acid

    MedlinePlus

    ... Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend on Facebook Tweet ... of the baby's brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  19. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour in ...

  20. Methylmalonic acid blood test

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003565.htm Methylmalonic acid blood test To use the sharing features on this page, please enable JavaScript. The methylmalonic acid blood test measures the amount of methylmalonic acid ...

  1. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  2. Fatty Acid Oxidation Disorders

    MedlinePlus

    ... other health conditions > Fatty acid oxidation disorders Fatty acid oxidation disorders E-mail to a friend Please ... these disorders, go to genetests.org . What fatty acid oxidation disorders are tested for in newborn screening? ...

  3. DISRUPTION OF THYROID HORMONE HOMEOSTASIS BY PERFLUROALKYL ACIDS

    EPA Science Inventory

    Perfluoroalkyl acids (PFAA) are man-made chemicals found ubiquitously in humans and wildlife; the major representatives of these are those with an 8-carbon chain (C-8, perfluorooctane sulfonate, PFOS and perfluorooctanoic acid, PFOA). Presently, we have investigated the effects o...

  4. Surface-active properties of humic and sulfochlorohumic acids

    SciTech Connect

    Ryabova, I.N.; Mustafina, G.A.; Akkulova, Z.G.; Satymbaeva, A.S.

    2009-10-15

    The surface tension of alkaline solutions of humic acids and their sulfochloroderivatives, which are synthesized by sulfonation of chlorohumic acids isolated from coal chlorinated by the electrochemical method, is investigated. It is established that humic compounds possess weak surface activity. Basic adsorption parameters are calculated.

  5. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  6. Chemical Agent Performance of Sulfonated Ionomeric Membranes for Chem/Bio Applications

    DTIC Science & Technology

    2008-12-01

    Polyisobutylene ( PIB ) Chemically Modified IB Sulfonic Acid Counter-ion (Ba, Mg, Ca, Zn, Cs)Block Copolymer Morphology Sulfonic acid...Mauritz, K., 2000: Diffusion of Alcohols Through Sulfonated PS/ PIB /PS Block Copolymers Using FTIR-ATR Spectroscopy, Polymer Materials: Engineering

  7. DETERMINATION OF CARBOXYLIC ACIDS BY ION-EXCLUSION CHROMATOGRAPHY WITH NON-SUPPRESSED CONDUCTIVITY AND OPTICAL DETECTORS

    EPA Science Inventory

    Determination of carboxylic acids using non-suppressed conductivity and UV detections is described. The background conductance of 1-octanesulfonic acid, hexane sulfonic acid and sulfuric acid at varying concentrations was determined. Using 0.2 mM 1-octanesulfonic acid as a mobile...

  8. Evidence for the Involvement of Xenobiotic-responsive Nuclear Receptors in Transcriptional Effects Upon Perfluoroalkyl Acid Exposure in Diverse Species.

    EPA Science Inventory

    Humans and other species have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotypic effects similar to pe...

  9. Evidence for the Involvement of Xenobiotic-response Nuclear Receptors in Transcriptional Effects Upon Perfluroroalkyl Acid Exposure in Diverse Species

    EPA Science Inventory

    Humans and ecological species have been found to have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotyp...

  10. Acid tolerance in amphibians

    SciTech Connect

    Pierce, B.A.

    1985-04-01

    Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

  11. Gas-phase acidities of aspartic acid, glutamic acid, and their amino acid amides

    NASA Astrophysics Data System (ADS)

    Li, Zhong; Matus, Myrna H.; Velazquez, Hector Adam; Dixon, David A.; Cassady, Carolyn J.

    2007-09-01

    Gas-phase acidities (GA or [Delta]Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage's importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3-4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

  12. Toxicity of adipic acid.

    PubMed

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests.

  13. Comparison of antioxidant activities of different parts from snow chrysanthemum (Coreopsis tinctoria Nutt.) and identification of their natural antioxidants using high performance liquid chromatography coupled with diode array detection and mass spectrometry and 2,2'-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt-based assay.

    PubMed

    Chen, L X; Hu, D J; Lam, S C; Ge, L; Wu, D; Zhao, J; Long, Z R; Yang, W J; Fan, B; Li, S P

    2016-01-08

    Snow chrysanthemum (Coreopsis tinctoria Nutt.), a world-widely well-known flower tea material, has attracted more and more attention because of its beneficial health effects such as antioxidant activity and special flavor. In this study, a high performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) and 2,2'-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt (ABTS) based assay was employed for comparison and identification of antioxidants in different samples of snow chrysanthemum. The results showed that snow chrysanthemum flowers possessed the highest while stems presented the lowest antioxidant capacities. Fourteen detected peaks with antioxidant activity were temporarily identified as 3,4',5,6,7-pentahydroxyflavanone-O-hexoside, chlorogenic acid, 2R-3',4',8-trihydroxyflavanone-7-O-glucoside, flavanomarein, flavanocorepsin, flavanokanin, quercetagitin-7-O-glucoside, 3',5,5',7-tetrahydroxyflavanone-O-hexoside, marein, maritimein, 1,3-dicaffeoylquinic acid, coreopsin, okanin and acetyl-marein by comparing their UV spectra, retention times and MS data with standards or literature data. Antioxidants existed in snow chrysanthemum are quite different from those reported in Chrysanthemum morifolium, a well-known traditional beverage in China, which indicated that snow chrysanthemum may be a promising herbal tea material with obvious antioxidant activity.

  14. Preparation of a novel carbon-based solid acid from cassava stillage residue and its use for the esterification of free fatty acids in waste cooking oil.

    PubMed

    Wang, Lingtao; Dong, Xiuqin; Jiang, Haoxi; Li, Guiming; Zhang, Minhua

    2014-04-01

    A novel carbon-based solid acid catalyst was prepared by the sulfonation of incompletely carbonized cassava stillage residue (CSR) with concentrated sulfuric acid, and employed to catalyze the esterification of methanol and free fatty acids (FFAs) in waste cooking oil (WCO). The effects of the carbonization and the sulfonation temperatures on the pore structure, acid density and catalytic activity of the CSR-derived catalysts were systematically investigated. Low temperature carbonization and high temperature sulfonation can cause the collapse of the carbon framework, while high temperature carbonization is not conducive to the attachment of SO3H groups on the surface. The catalyst showed high catalytic activity for esterification, and the acid value for WCO is reduced to below 2mg KOH/g after reaction. The activity of catalyst can be well maintained after five cycles. CSR can be considered a promising raw material for the production of a new eco-friendly solid acid catalyst.

  15. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    This communication notes the actual magnitude of the acidity in acidic fog particles and suggests a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air.

  16. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  17. Survey of organic acid eluents for anion chromatography

    SciTech Connect

    Book, D.E.

    1981-10-01

    Of all the potential eluents surveyed (including aromatic, sulfonic, phosphonic, among other acids), only the carboxylic acids and the nitrophenols are recommended as eluents for anion chromatography. The concentration of the eluent should be in the range 5 x 10/sup -5/ to 1 x 10/sup -3/ M. The eluent should have the same charge as inorganic anions, a higher charge than organic acid samples. Choice of eluents for separation of halides, chloride and sulfate, multivalent inorganic anions, small alkyl acids, and aromatic acids is discussed. (DLC)

  18. Comparison of antioxidant effectiveness of lipoic acid and dihydrolipoic acid.

    PubMed

    Zhao, Feng; Liu, Zai-Qun

    2011-01-01

    The abilities of dihydrolipoic acid (DHLA) to scavenge peroxynitrite (ONOO(-) ), galvinoxyl radical, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cation radical (ABTS(+•) ), and 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) were higher than those of lipoic acid (LA). The effectiveness of DHLA to protect methyl linoleate against 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH)-induced oxidation was about 2.2-fold higher than that of LA, and DHLA can retard the autoxidation of linoleic acid (LH) in the β-carotene-bleaching test. DHLA can also trap ∼0.6 radicals in AAPH-induced oxidation of LH. Moreover, DHLA can scavenge ∼2.0 radicals in AAPH-induced oxidation of DNA and AAPH-induced hemolysis of erythrocytes, whereas LA can scavenge ∼1.5 radicals at the same experimental conditions. DHLA can protect erythrocytes against hemin-induced hemolysis, but accelerate the degradation of DNA in the presence of Cu(2+) . Therefore, the antioxidant capacity of -SH in DHLA is higher than S-S in LA.

  19. Fatty acid analogs

    DOEpatents

    Elmaleh, David R.; Livni, Eli

    1985-01-01

    In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

  20. Omega-3 fatty acids

    PubMed Central

    Schwalfenberg, Gerry

    2006-01-01

    OBJECTIVE To examine evidence for the role of omega-3 fatty acids in cardiovascular disease. QUALITY OF EVIDENCE PubMed was searched for articles on the role of omega-3 fatty acids in cardiovascular disease. Level I and II evidence indicates that omega-3 fatty acids are beneficial in improving cardiovascular outcomes. MAIN MESSAGE Dietary intake of omega-3 fatty acids has declined by 80% during the last 100 years, while intake of omega-6 fatty acids has greatly increased. Omega-3 fatty acids are cardioprotective mainly due to beneficial effects on arrhythmias, atherosclerosis, inflammation, and thrombosis. There is also evidence that they improve endothelial function, lower blood pressure, and significantly lower triglycerides. CONCLUSION There is good evidence in the literature that increasing intake of omega-3 fatty acids improves cardiac outcomes. Physicians need to integrate dietary recommendations for consumption of omega-3 fatty acids into their usual cardiovascular care. PMID:16812965

  1. Sulfuric acid poisoning

    MedlinePlus

    Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This article is for information only. Do NOT ...

  2. Lactic acid test

    MedlinePlus

    Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...

  3. Folic Acid Quiz

    MedlinePlus

    ... About Us Information For... Media Policy Makers Folic Acid Quiz Language: English Español (Spanish) Recommend on Facebook ... button beside the question. Good Luck! 1. Folic acid is: A a B vitamin B a form ...

  4. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  5. Azelaic Acid Topical

    MedlinePlus

    Azelaic acid gel and foam is used to clear the bumps, lesions, and swelling caused by rosacea (a skin ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat the pimples and ...

  6. Zoledronic Acid Injection

    MedlinePlus

    Zoledronic acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and weak ... of life,' end of regular menstrual periods). Zoledronic acid (Reclast) is also used to treat osteoporosis in ...

  7. Alpha Hydroxy Acids

    MedlinePlus

    ... Cosmetics Home Cosmetics Products & Ingredients Ingredients Alpha Hydroxy Acids Share Tweet Linkedin Pin it More sharing options ... for Industry: Labeling for Cosmetics Containing Alpha Hydroxy Acids The following information is intended to answer questions ...

  8. Uric Acid Test

    MedlinePlus

    ... products and services. Advertising & Sponsorship: Policy | Opportunities Uric Acid Share this page: Was this page helpful? Also known as: Serum Urate; UA Formal name: Uric Acid Related tests: Synovial Fluid Analysis , Kidney Stone Analysis , ...

  9. Amino Acid Metabolism Disorders

    MedlinePlus

    ... breaks the food parts down into sugars and acids, your body's fuel. Your body can use this ... process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple ...

  10. Valproic Acid and Pregnancy

    MedlinePlus

    ... live chat Live Help Fact Sheets Share Valproic Acid and Pregnancy Wednesday, 01 July 2015 In every ... This sheet talks about whether exposure to valproic acid may increase the risk for birth defects over ...

  11. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  12. Omega-6 Fatty Acids

    MedlinePlus

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...

  13. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  14. PRODUCTION OF TRIFLUOROACETIC ACID

    DOEpatents

    Haworth, W.N.; Stacey, M.

    1949-07-19

    A method is given for the production of improved yields of trifluoroacetic acid. The compound is prepared by oxidizing m-aminobenzotrifluoride with an alkali metal or alkaline earth metal permanganate at a temperature in the range of 80 deg C to 100 deg C while dissolved ln a mixture of water with glacial acetic acid and/or trifluoroacetic acid. Preferably a mixture of water and trifluoroacetic acid ls used as the solvent.

  15. Refining Lurgi tar acids

    SciTech Connect

    Greco, N.P.

    1984-04-17

    There is disclosed a process for removing tar bases and neutral oils from the Lurgi tar acids by treating the tar acids with aqueous sodium bisulfate to change the tar bases to salts and to hydrolyze the neutral oils to hydrolysis products and distilling the tar acids to obtain refined tar acid as the distillate while the tar base salts and neutral oil hydrolysis products remain as residue.

  16. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  17. Preparation and characterization of biomass carbon-based solid acid catalyst for the esterification of oleic acid with methanol.

    PubMed

    Liu, Tiantian; Li, Zhilong; Li, Wei; Shi, Congjiao; Wang, Yun

    2013-04-01

    A solid acid catalyst, prepared by sulfonating carbonized corn straw, was proved to be an efficient and environmental benign catalyst for the esterification of oleic acid and methanol. Various synthetic parameters, such as carbonization temperature and time were systematically examined. It was found that the catalyst exhibited the highest acid density of 2.64 mmol/g by NaOH titration. A quantitative yield (98%) of ester was achieved, using the most active sulfonated catalyst at 333 K with a 7 wt.% catalyst/oleic acid ratio for 4h, at a 7:1 M ratio of methanol/oleic acid, while the commercial available Amberlyst-15 only gave 85% yield under the same reaction condition.

  18. 78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... AGENCY 40 CFR Part 180 Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic..., polymer with adipic acid, linoleic acid, oleic acid and ricinoleic acid (CAS Reg. No. 1357486-09- 9) when used as an inert ingredient in a pesticide formulation. Advance Polymer Technology submitted a...

  19. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    The chemical composition of fog particles has become of considerable interest, because of both the possibility of interpreting atmospheric- chemistry processes in fog particles in terms of the principles of aqueous chemistry and the potential health effects of species present in fog particles. The acidity of fog particles has received wide attention. This communication noted the actual magnitude of the excess acidity in acidic fog particles and suggested a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air. (DP)

  20. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  1. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  2. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  3. Acid Lipase Disease

    MedlinePlus

    ... Page You are here Home » Disorders » All Disorders Acid Lipase Disease Information Page Acid Lipase Disease Information Page What research is being ... research to understand lipid storage diseases such as acid lipase deficiency. Additional research studies hope to identify ...

  4. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  5. Esterification of fatty acid catalyzed by hydrothermally stable propylsulfonic acid-functionalized mesoporous silica SBA-15.

    PubMed

    Mar, Win Win; Somsook, Ekasith

    2013-01-01

    Propylsulfonic acid-functionalized mesoporous silica SBA-15 has been synthesized via one-step strategy at 130°C based on the co-condensation of TEOS and MPTMS in the presence of Pluronic 123 polymer and H₂O₂ in HCl aqueous solution. The synthesized solid exhibited hydrothermal stability in boiling water without significant change in textural properties. The catalytic performance of the synthesized solid was studied in the esterification of oleic acid with methanol. The experimental results revealed that the large mesopore structures of SBA-15-PrSO₃H solid synthesized at 130°C could favor a facile access of oleic acid to the acid sites, making the comparable activity to that of phenyl ethyl sulfonic acid functionalized silica and higher than that of dry amberlyst-15.

  6. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow; Mary Ann D.; Dahlberg, James E.

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  7. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  8. Editorial: Acid precipitation

    SciTech Connect

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  9. Nucleic acid detection compositions

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James L.

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  10. Nucleic acid detection assays

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  11. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor L.; Brow, Mary Ann D.; Dahlberg, James E.

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  12. Tandem bis-aza-Michael addition reaction of amines in aqueous medium promoted by polystyrenesulfonic Acid

    EPA Science Inventory

    An efficient and environmentally benign tandem bis-aza-Michael addition of amines catalyzed by polystyrene sulfonic acid (PSSA) is described. This operationally simple high yielding microwave assisted synthetic protocol proceeded in water in the absence of any organic solvent.

  13. TOXICOGENOMIC DISSECTION OF RODENT LIVER TRANSCRIPT PROFILES AFTER EXPOSURE TO PERFLUOROALKYL ACIDS

    EPA Science Inventory

    Exposure to peroxisome proliferator chemicals (PPC) leads to alterations in the balance between hepatocyte growth and apoptosis, increases in liver to body weight ratios and liver tumors. The perfluoroalkyl acids including perfluorooctanoate (PFOA) and perfluorooctane sulfonate (...

  14. The Feasibility of Concentrating/Separating Dilute Nitrocellulose Acid Wastewaters by Reverse Osmosis

    DTIC Science & Technology

    1974-11-01

    Preliminary laboratory investigations using commercially available cellulose - acetate reverse osmosis (RO) membranes were conducted. The objective of this... cellulose - acetate to hydrolysis when continuously exposed in an acidic environment. The application of cellulose - acetate and modified sulfonated

  15. Nucleic acid detection kits

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  16. [Biosynthesis of adipic acid].

    PubMed

    Han, Li; Chen, Wujiu; Yuan, Fei; Zhang, Yuanyuan; Wang, Qinhong; Ma, Yanhe

    2013-10-01

    Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.

  17. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  18. Boric acid and boronic acids inhibition of pigeonpea urease.

    PubMed

    Reddy, K Ravi Charan; Kayastha, Arvind M

    2006-08-01

    Urease from the seeds of pigeonpea was competitively inhibited by boric acid, butylboronic acid, phenylboronic acid, and 4-bromophenylboronic acid; 4-bromophenylboronic acid being the strongest inhibitor, followed by boric acid > butylboronic acid > phenylboronic acid, respectively. Urease inhibition by boric acid is maximal at acidic pH (5.0) and minimal at alkaline pH (10.0), i.e., the trigonal planar B(OH)3 form is a more effective inhibitor than the tetrahedral B(OH)4 -anionic form. Similarly, the anionic form of phenylboronic acid was least inhibiting in nature.

  19. Biotransformation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid by plant cell cultures of Eucalyptus perriniana.

    PubMed

    Katsuragi, Hisashi; Shimoda, Kei; Kubota, Naoji; Nakajima, Nobuyoshi; Hamada, Hatsuyuki; Hamada, Hiroki

    2010-01-01

    Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.

  20. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  1. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  2. Stable, fluorinated acid amplifiers for use in EUV lithography

    NASA Astrophysics Data System (ADS)

    Kruger, Seth; Hosoi, Kenji; Cardineau, Brian; Miyauchi, Koichi; Brainard, Robert

    2012-03-01

    This paper presents two new concepts that together provide a 100,000X improvement in stability for AAs that produce highly-fluorinated, strong sulfonic acids. These two new design concepts are based on (1) an olefin-trigger structure and (2) a trifluoromethyl group alpha to the sulfonic ester. These new concepts led to the synthesis of the first stable acid amplifier that generates triflate acid and for the synthesis of AAs that are stable enough to be used as monomers in free-radical polymerization reactions yet produce very strong, fluorinated acids. Lastly, we present preliminary results where one new AA is able to improve the LER of a control resist from 4.6 +/- 0.5 nm to 2.1 +/- 0.1 nm.

  3. Citric Acid Alternative to Nitric Acid Passivation

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  4. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  5. Recovery of organic acids

    DOEpatents

    Verser, Dan W [Menlo Park, CA; Eggeman, Timothy J [Lakewood, CO

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  6. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  7. Parenteral Nutrition: Amino Acids.

    PubMed

    Hoffer, Leonard John

    2017-03-10

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

  8. Parenteral Nutrition: Amino Acids

    PubMed Central

    Hoffer, Leonard John

    2017-01-01

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness. PMID:28287411

  9. Hydrogen-bonded aggregates in precise acid copolymers

    SciTech Connect

    Lueth, Christopher A.; Bolintineanu, Dan S.; Stevens, Mark J. Frischknecht, Amalie L.

    2014-02-07

    We perform atomistic molecular dynamics simulations of melts of four precise acid copolymers, two poly(ethylene-co-acrylic acid) (PEAA) copolymers, and two poly(ethylene-co-sulfonic acid) (PESA) copolymers. The acid groups are spaced by either 9 or 21 carbons along the polymer backbones. Hydrogen bonding causes the acid groups to form aggregates. These aggregates give rise to a low wavevector peak in the structure factors, in agreement with X-ray scattering data for the PEAA materials. The structure factors for the PESA copolymers are very similar to those for the PEAA copolymers, indicating a similar distance between aggregates which depends on the spacer length but not on the nature of the acid group. The PEAA copolymers are found to form more dimers and other small aggregates than do the PESA copolymers, while the PESA copolymers have both more free acid groups and more large aggregates.

  10. Diterpenoid acids from Grindelia nana.

    PubMed

    Mahmoud, A A; Ahmed, A A; Tanaka, T; Iinuma, M

    2000-03-01

    Two new norditerpenoid acids of the labdane-type (norgrindelic acids), 4,5-dehydro-6-oxo-18-norgrindelic acid (1) and 4beta-hydroxy-6-oxo-19-norgrindelic acid (2), as well as a new grindelic acid derivative, 18-hydroxy-6-oxogrindelic acid (3), were isolated from the aerial parts of Grindelia nana. In addition, the known compounds, 6-oxogrindelic acid, grindelic acid, methyl grindeloate, 7alpha,8alpha-epoxygrindelic acid, and 4alpha-carboxygrindelic acid were also isolated. The structures of the new compounds were characterized on the basis of spectroscopic analysis.

  11. Facile synthesis of highly efficient and recyclable magnetic solid acid from biomass waste

    PubMed Central

    Liu, Wu-Jun; Tian, Ke; Jiang, Hong; Yu, Han-Qing

    2013-01-01

    In this work, sawdust, a biomass waste, is converted into a magnetic porous carbonaceous (MPC) solid acid catalyst by an integrated fast pyrolysis–sulfonation process. The resultant magnetic solid acid has a porous structure with high surface area of 296.4 m2 g−1, which can be attributed to the catalytic effect of Fe. The catalytic activity and recyclability of the solid acid catalyst are evaluated during three typical acid-catalyzed reactions: esterification, dehydration, and hydrolysis. The favorable catalytic performance in all three reactions is attributed to the acid's high strength with 2.57 mmol g−1 of total acid sites. Moreover, the solid acid can be reused five times without a noticeable decrease in catalytic activity, indicating the stability of the porous carbon (PC)–sulfonic acid group structure. The findings in the present work offer effective alternatives for environmentally friendly utilization of abundant biomass waste. PMID:23939253

  12. Structure of Acid phosphatases.

    PubMed

    Araujo, César L; Vihko, Pirkko T

    2013-01-01

    Acid phosphatases are enzymes that have been studied extensively due to the fact that their dysregulation is associated with pathophysiological conditions. This characteristic has been exploited for the development of diagnostic and therapeutic methods. As an example, prostatic acid phosphatase was the first marker for metastatic prostate cancer diagnosis and the dysregulation of tartrate resistant acid phosphatase is associated with abnormal bone resorption linked to osteoporosis. The pioneering crystallization studies on prostatic acid phosphatase and mammalian tartrate-resistant acid phosphatase conformed significant milestones towards the elucidation of the mechanisms followed by these enzymes (Schneider et al., EMBO J 12:2609-2615, 1993). Acid phosphatases are also found in nonmammalian species such as bacteria, fungi, parasites, and plants, and most of them share structural similarities with mammalian acid phosphatase enzymes. Acid phosphatase (EC 3.1.3.2) enzymes catalyze the hydrolysis of phosphate monoesters following the general equation. Phosphate monoester + H2O -->/<-- alcohol + phosphate. The general classification "acid phosphatase" relies only on the optimum acidic pH for the enzymatic activity in assay conditions using non-physiological substrates. These enzymes accept a wide range of substrates in vitro, ranging from small organic molecules to phosphoproteins, constituting a heterogeneous group of enzymes from the structural point of view. These structural differences account for the divergence in cofactor dependences and behavior against substrates, inhibitors, and activators. In this group only the tartrate-resistant acid phosphatase is a metallo-enzyme whereas the other members do not require metal-ion binding for their catalytic activity. In addition, tartrate-resistant acid phosphatase and erythrocytic acid phosphatase are not inhibited by L-(+)-tartrate ion while the prostatic acid phosphatase is tartrate-sensitive. This is an important

  13. Folic Acid and Pregnancy

    MedlinePlus

    ... Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Your Child's Development (Birth to 3 Years) Feeding Your 1- to 3-Month-Old Feeding Your 4- to 7-Month-Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old Folic Acid ... > For Parents > Folic Acid and Pregnancy A A A What's ...

  14. Bile acid transporters

    PubMed Central

    Dawson, Paul A.; Lan, Tian; Rao, Anuradha

    2009-01-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na+ taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTα-OSTβ. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers. PMID:19498215

  15. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  16. Salicylic Acid Topical

    MedlinePlus

    Propa pH® Peel-Off Acne Mask ... pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat ... medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked ...

  17. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  18. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like ... people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  19. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  20. Production of shikimic acid.

    PubMed

    Ghosh, Saptarshi; Chisti, Yusuf; Banerjee, Uttam C

    2012-01-01

    Shikimic acid is a key intermediate for the synthesis of the antiviral drug oseltamivir (Tamiflu®). Shikimic acid can be produced via chemical synthesis, microbial fermentation and extraction from certain plants. An alternative production route is via biotransformation of the more readily available quinic acid. Much of the current supply of shikimic acid is sourced from the seeds of Chinese star anise (Illicium verum). Supply from star anise seeds has experienced difficulties and is susceptible to vagaries of weather. Star anise tree takes around six-years from planting to bear fruit, but remains productive for long. Extraction and purification from seeds are expensive. Production via fermentation is increasing. Other production methods are too expensive, or insufficiently developed. In the future, production in recombinant microorganisms via fermentation may become established as the preferred route. Methods for producing shikimic acid are reviewed.

  1. Fatty acid production from amino acids and alpha-keto acids by Brevibacterium linens BL2.

    PubMed

    Ganesan, Balasubramanian; Seefeldt, Kimberly; Weimer, Bart C

    2004-11-01

    Low concentrations of branched-chain fatty acids, such as isobutyric and isovaleric acids, develop during the ripening of hard cheeses and contribute to the beneficial flavor profile. Catabolism of amino acids, such as branched-chain amino acids, by bacteria via aminotransferase reactions and alpha-keto acids is one mechanism to generate these flavorful compounds; however, metabolism of alpha-keto acids to flavor-associated compounds is controversial. The objective of this study was to determine the ability of Brevibacterium linens BL2 to produce fatty acids from amino acids and alpha-keto acids and determine the occurrence of the likely genes in the draft genome sequence. BL2 catabolized amino acids to fatty acids only under carbohydrate starvation conditions. The primary fatty acid end products from leucine were isovaleric acid, acetic acid, and propionic acid. In contrast, logarithmic-phase cells of BL2 produced fatty acids from alpha-keto acids only. BL2 also converted alpha-keto acids to branched-chain fatty acids after carbohydrate starvation was achieved. At least 100 genes are potentially involved in five different metabolic pathways. The genome of B. linens ATCC 9174 contained these genes for production and degradation of fatty acids. These data indicate that brevibacteria have the ability to produce fatty acids from amino and alpha-keto acids and that carbon metabolism is important in regulating this event.

  2. Total syntheses of cis-cyclopropane fatty acids: dihydromalvalic acid, dihydrosterculic acid, lactobacillic acid, and 9,10-methylenehexadecanoic acid.

    PubMed

    Shah, Sayali; White, Jonathan M; Williams, Spencer J

    2014-12-14

    cis-Cyclopropane fatty acids (cis-CFAs) are widespread constituents of the seed oils of subtropical plants, membrane components of bacteria and protozoa, and the fats and phospholipids of animals. We describe a systematic approach to the synthesis of enantiomeric pairs of four cis-CFAs: cis-9,10-methylenehexadecanoic acid, lactobacillic acid, dihydromalvalic acid, and dihydrosterculic acid. The approach commences with Rh2(OAc)4-catalyzed cyclopropenation of 1-octyne and 1-decyne, and hinges on the preparative scale chromatographic resolution of racemic 2-alkylcycloprop-2-ene-1-carboxylic acids using a homochiral Evan's auxiliary. Saturation of the individual diastereomeric N-cycloprop-2-ene-1-carbonylacyloxazolidines, followed by elaboration to alkylcyclopropylmethylsulfones, allowed Julia-Kocienski olefination with various ω-aldehyde-esters. Finally, saponification and diimide reduction afforded the individual cis-CFA enantiomers.

  3. Separation of aliphatic carboxylic acids and benzenecarboxylic acids by ion-exclusion chromatography with various cation-exchange resin columns and sulfuric acid as eluent.

    PubMed

    Ohta, Kazutoku; Ohashi, Masayoshi; Jin, Ji-Ye; Takeuchi, Toyohide; Fujimoto, Chuzo; Choi, Seong-Ho; Ryoo, Jae-Jeong; Lee, Kwang-Pill

    2003-05-16

    The application of various hydrophilic cation-exchange resins for high-performance liquid chromatography (sulfonated silica gel: TSKgel SP-2SW, carboxylated silica gel: TSKgel CM-2SW, sulfonated polymethacrylate resin: TSKgel SP-5PW, carboxylated polymethacrylate resins: TSKgel CM-5PW and TSKgel OA-Pak A) as stationary phases in ion-exclusion chromatography for C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, butyric, isovaleric, valeric, isocaproic, caproic, 2-methylhexanoic and heptanoic acids) and benzenecarboxylic acids (pyromellitic, trimellitic, hemimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic, salicylic acids and phenol) was carried out using diluted sulfuric acid as the eluent. Silica-based cation-exchange resins (TSKgel SP-2SW and TSKgel CM-2SW) were very suitable for the ion-exclusion chromatographic separation of these benzenecarboxylic acids. Excellent simultaneous separation of these benzenecarboxylic acids was achieved on a TSKgel SP-2SW column (150 x 6 mm I.D.) in 17 min using a 2.5 mM sulfuric acid at pH 2.4 as the eluent. Polymethacrylate-based cation-exchange resins (TSKgel SP-5PW, TSKgel CM-5PW and TSKgel OA-Pak A) acted as advanced stationary phases for the ion-exclusion chromatographic separation of these C1-C7 aliphatic carboxylic acids. Excellent simultaneous separation of these C1-C7 acids was achieved on a TSKgel CM-5PW column (150 x 6 mm I.D.) in 32 min using a 0.05 mM sulfuric acid at pH 4.0 as the eluent.

  4. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  5. Trans Fatty Acids

    NASA Astrophysics Data System (ADS)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  6. Gluconic acid production.

    PubMed

    Anastassiadis, Savas; Morgunov, Igor G

    2007-01-01

    Gluconic acid, the oxidation product of glucose, is a mild neither caustic nor corrosive, non toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries. Present review article presents the comprehensive information of patent bibliography for the production of gluconic acid and compares the advantages and disadvantages of known processes. Numerous manufacturing processes are described in the international bibliography and patent literature of the last 100 years for the production of gluconic acid from glucose, including chemical and electrochemical catalysis, enzymatic biocatalysis by free or immobilized enzymes in specialized enzyme bioreactors as well as discontinuous and continuous fermentation processes using free growing or immobilized cells of various microorganisms, including bacteria, yeast-like fungi and fungi. Alternatively, new superior fermentation processes have been developed and extensively described for the continuous and discontinuous production of gluconic acid by isolated strains of yeast-like mold Aureobasidium pullulans, offering numerous advantages over the traditional discontinuous fungi processes.

  7. Strongly Acidic Auxin Indole-3-Methanesulfonic Acid

    PubMed Central

    Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

    1985-01-01

    A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

  8. Design, synthesis, and biological evaluation of 4-(5-dimethylamino-naphthalene-1-sulfon-amido)-3-(4-iodophenyl)butanoic acid as a novel molecular probe for apoptosis imaging

    SciTech Connect

    Zeng, Wenbin; Miao, Weimin; Le Puil, Michael; Shi, Guangqing; Biggerstaff, John; Kabalka, George W.; Townsend, David

    2010-07-30

    Research highlights: {yields} Annexin V is the gold standard probe for imaging apoptosis. {yields} Unfavorable profiles of Annexin V make it difficult to apply in the clinic. {yields} A novel small-molecular probe DNSBA was designed as an alternative to Annexin V. {yields} DNSBA specifically and selectively detect apoptotic cancer cells at all stages. {yields} DNSBA is a potential SPECT and PET agent when labeled with radioiodine. -- Abstract: Apoptosis (programmed cell death) plays a crucial role in the pathogenesis of many disorders, thus the detection of apoptotic cells can provide the physician with important information to further therapeutic strategies and would substantially advance patient care. A small molecule, 4-(5-dimethylamino-naphthalene-1-sulfonamido)-3-(4-iodo-phenyl)butanoic acid (DNSBA), was designed as a novel probe for imaging apoptosis and synthesized with good yield. The biological characterization demonstrated that DNSBA can be used to specifically and selectively detect apoptotic cancer cells at all stages. DNSBA is also designed as a potential SPECT and PET probe when labeled with radioiodine (I-123, -124, and -131).

  9. Separation of certain carboxylic acids utilizing cation exchange membranes

    DOEpatents

    Chum, H.L.; Sopher, D.W.

    1983-05-09

    A method of substantially separating monofunctional lower carboxylic acids from a liquid mixture containing the acids wherein the pH of the mixture is adjusted to a value in the range of from about 1 to about 5 to form protonated acids. The mixture is heated to an elevated temperature not greater than about 100/sup 0/C and brought in contact with one side of a perfluorinated cation exchange membrane having sulfonate or carboxylate groups or mixtures thereof with the mixture containing the protonated acids. A pressure gradient can be established across the membrane with the mixture being under higher pressure, so that protonated monofunctional lower carboxylic acids pass through the membrane at a substantially faster rate than the remainder of the mixture thereby substantially separating the acids from the mixture.

  10. Separation of certain carboxylic acids utilizing cation exchange membranes

    DOEpatents

    Chum, Helena L.; Sopher, David W.

    1984-01-01

    A method of substantially separating monofunctional lower carboxylic acids from a liquid mixture containing the acids wherein the pH of the mixture is adjusted to a value in the range of from about 1 to about 5 to form protonated acids. The mixture is heated to an elevated temperature not greater than about 100.degree. C. and brought in contact with one side of a perfluorinated cation exchange membrane having sulfonate or carboxylate groups or mixtures thereof with the mixture containing the protonated acids. A pressure gradient can be established across the membrane with the mixture being under higher pressure, so that protonated monofunctional lower carboxylic acids pass through the membrane at a substantially faster rate than the remainder of the mixture thereby substantially separating the acids from the mixture.

  11. EFFECT OF THE CATION ON SOLUBILIZATION BY OIL-SOLUBLE SULFONATES AND THE APPLICABILITY OF THE MASS LAW,

    DTIC Science & Technology

    SURFACE ACTIVE SUBSTANCES, *SULFONATES), ORGANIC SOLVENTS, SOLUBILITY, COLLOIDS, CESIUM COMPOUNDS, SODIUM COMPOUNDS, BARIUM COMPOUNDS, MAGNESIUM COMPOUNDS, ZINC COMPOUNDS, CARBINOLS, AMINES, ACETIC ACID , TOLUENES, GAS CHROMATOGRAPHY, MOLECULAR ASSOCIATION

  12. Aminolevulinic Acid Topical

    MedlinePlus

    ... under the skin that result from exposure to sunlight and can develop into skin cancer) of the ... acid will make your skin very sensitive to sunlight (likely to get sunburn). Avoid exposure of treated ...

  13. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  14. Folic acid - test

    MedlinePlus

    ... folic acid before and during pregnancy helps prevent neural tube defects, such as spina bifida. Women who ... take more if they have a history of neural tube defects in earlier pregnancies. Ask your provider ...

  15. Acid soldering flux poisoning

    MedlinePlus

    The harmful substances in soldering fluxes are called hydrocarbons. They include: Ammonium chloride Rosin Hydrochloric acid Zinc ... Lee DC. Hydrocarbons. In: Marx JA, Hockberger RS, Walls RM, et ... Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ...

  16. Amoxicillin and Clavulanic Acid

    MedlinePlus

    ... Amoxicillin is in a class of medications called penicillin-like antibiotics. It works by stopping the growth ... allergic to amoxicillin (Amoxil, Trimox, Wymox), clavulanic acid, penicillin, cephalosporins, or any other medications.tell your doctor ...

  17. Amino Acid Metabolism Disorders

    MedlinePlus

    ... acidemia? In ASA, the body can’t remove ammonia or a substance called argininosuccinic acid from the ... and children include: Breathing problems High levels of ammonia in the bloodIntense headache, especially after a high- ...

  18. [Hydrofluoric acid burns].

    PubMed

    Holla, Robin; Gorter, Ramon R; Tenhagen, Mark; Vloemans, A F P M Jos; Breederveld, Roelf S

    2016-01-01

    Hydrofluoric acid is increasingly used as a rust remover and detergent. Dermal contact with hydrofluoric acid results in a chemical burn characterized by severe pain and deep tissue necrosis. It may cause electrolyte imbalances with lethal consequences. It is important to identify high-risk patients. 'High risk' is defined as a total affected body area > 3% or exposure to hydrofluoric acid in a concentration > 50%. We present the cases of three male patients (26, 31, and 39 years old) with hydrofluoric acid burns of varying severity and describe the subsequent treatments. The application of calcium gluconate 2.5% gel to the skin is the cornerstone of the treatment, reducing pain as well as improving wound healing. Nails should be thoroughly inspected and possibly removed if the nail is involved, to ensure proper healing. In high-risk patients, plasma calcium levels should be evaluated and cardiac monitoring is indicated.

  19. Citric acid urine test

    MedlinePlus

    ... used to diagnose renal tubular acidosis and evaluate kidney stone disease. Normal Results The normal range is 320 ... tubular acidosis and a tendency to form calcium kidney stones. The following may decrease urine citric acid levels: ...

  20. Lead/acid batteries

    NASA Astrophysics Data System (ADS)

    Bullock, Kathryn R.

    Lead/acid batteries are produced in sizes from less than 1 to 3000 Ah for a wide variety of portable, industrial and automotive applications. Designs include Planté, Fauré or pasted, and tubular electrodes. In addition to the traditional designs which are flooded with sulfuric acid, newer 'valve-regulated" designs have the acid immolibized in a silica gel or absorbed in a porous glass separator. Development is ongoing worldwide to increase the specific power, energy and deep discharge cycle life of this commercially successful system to meet the needs of new applications such as electric vehicles, load leveling, and solar energy storage. The operating principles, current status, technical challenges and commercial impact of the lead/acid battery are reviewed.