Science.gov

Sample records for alkyl polycarboxylic acids

  1. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  2. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  3. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  4. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  5. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  6. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  7. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  8. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  9. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  10. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  11. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polycarboxylic acid ester (generic... Substances § 721.3110 Polycarboxylic acid ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polycarboxylic acid...

  12. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polycarboxylic acid ester (generic... Substances § 721.3110 Polycarboxylic acid ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polycarboxylic acid...

  13. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polycarboxylic acid ester (generic... Substances § 721.3110 Polycarboxylic acid ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polycarboxylic acid...

  14. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polycarboxylic acid ester (generic... Substances § 721.3110 Polycarboxylic acid ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polycarboxylic acid...

  15. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polycarboxylic acid ester (generic... Substances § 721.3110 Polycarboxylic acid ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polycarboxylic acid...

  16. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts....

  17. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts....

  18. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts....

  19. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid salts....

  20. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid salts....

  1. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid salts....

  2. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts....

  3. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid salts....

  4. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts....

  5. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid salts....

  6. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... salt (generic). 721.2098 Section 721.2098 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under...

  7. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... salt (generic). 721.2098 Section 721.2098 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under...

  8. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... salt (generic). 721.2098 Section 721.2098 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under...

  9. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... salt (generic). 721.2098 Section 721.2098 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under...

  10. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... salt (generic). 721.2098 Section 721.2098 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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.

  17. Calcite crystal growth rate inhibition by polycarboxylic acids

    USGS Publications Warehouse

    Reddy, M.M.; Hoch, A.R.

    2001-01-01

    Calcite crystal growth rates measured in the presence of several polycarboxyclic acids show that tetrahydrofurantetracarboxylic acid (THFTCA) and cyclopentanetetracarboxylic acid (CPTCA) are effective growth rate inhibitors at low solution concentrations (0.01 to 1 mg/L). In contrast, linear polycarbocylic acids (citric acid and tricarballylic acid) had no inhibiting effect on calcite growth rates at concentrations up to 10 mg/L. Calcite crystal growth rate inhibition by cyclic polycarboxyclic acids appears to involve blockage of crystal growth sites on the mineral surface by several carboxylate groups. Growth morphology varied for growth in the absence and in the presence of both THFTCA and CPTCA. More effective growth rate reduction by CPTCA relative to THFTCA suggests that inhibitor carboxylate stereochemical orientation controls calcite surface interaction with carboxylate inhibitors. ?? 20O1 Academic Press.

  18. Supramolecular assemblies of 4,7-phenanthroline with various aromatic polycarboxylic acids

    NASA Astrophysics Data System (ADS)

    Biswas, Sharmita Nandy; Nandy, Purnendu

    2016-10-01

    Five molecular complexes 1a-1e, of 4,7-phenanthroline (1) with various aromatic polycarboxylic acids such as benzene-1,3-dicarboxylic acid (a), pyridine-2,6-dicarboxylic acid (b), pyridine-2,5-dicarboxylic acid (c), benzene-1,2,3,4,5-pentacarboxylic acid (d) and 1,2,3,4,5,6-benzenehexacarboxylic acid (e) have been prepared and characterized by single crystal X-ray diffraction and thermogravimetric analyses. The analysis shows that all the assemblies crystallized as hydrates, except complex, 1c, formed between 1 and pyridine-2,5-dicarboxylic acid. Single crystal X-ray data reveals that the packing patterns of all the molecular complexes have been directed by strong hydrogen bonding O-H⋯O/O-H⋯N/N+-H⋯O- and weak hydrogen bonding C-H⋯O interactions. All the hydrated assemblies aggregate through the formation of cyclic networks as basic recognition pattern. Further, we observed that water molecules play significant role for production of supramolecular assemblies.

  19. Extraneous carbon assessment in ultra-microscale radiocarbon analysis using benzene polycarboxylic acids (BPCA)

    NASA Astrophysics Data System (ADS)

    Hanke, Ulrich M.; McIntyre, Cameron P.; Schmidt, Michael W. I.; Wacker, Lukas; Eglinton, Timothy I.

    2016-04-01

    Measurements of the natural abundance of radiocarbon (14C) concentrations in inorganic and organic carbon-containing materials can be used to investigate their date of origin. Particularly, the biogeochemical cycling of specific compounds in the environment may be investigated applying molecular marker analyses. However, the isolation of specific molecules from environmental matrices requires a complex processing procedure resulting in small sample sizes that often contain less than 30 μg C. Such small samples are sensitive to extraneous carbon (Cex) that is introduced during the purification of the compounds (Shah and Pearson, 2007). We present a thorough radiocarbon blank assessment for benzene polycarboxylic acids (BPCA), a proxy for combustion products that are formed during the oxidative degradation of condensed polyaromatic structures (Wiedemeier et al, in press). The extraneous carbon assessment includes reference material for (1) chemical extraction, (2) preparative liquid chromatography (3) wet chemical oxidation which are subsequently measured with gas ion source AMS (Accelerator Mass Spectrometer, 5-100 μg C). We always use pairs of reference materials, radiocarbon depleted (14Cfossil) and modern (14Cmodern) to determine the fraction modern (F14C) of Cex.Our results include detailed information about the quantification of Cex in radiocarbon molecular marker analysis using BPCA. Error propagation calculations indicate that ultra-microscale samples (20-30 μg) are feasible with uncertainties of less than 10 %. Calculations of the constant contamination reveal important information about the source (F14C) and mass (μg) of Cex (Wacker and Christl, 2011) for each sub procedure. An external correction of compound specific radiocarbon data is essential for robust results that allow for a high degree of confidence in the 14C results. References Shah and Pearson, 2007. Ultra-microscale (5-25μg C) analysis of individual lipids by 14C AMS: Assessment and

  20. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid, alkyl and substituted alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted...

  1. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid, alkyl and substituted alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted...

  2. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid, alkyl and substituted alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted...

  3. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid, alkyl and substituted alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted...

  4. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid, alkyl and substituted alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted...

  5. PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

    DOEpatents

    Grinstead, R.R.

    1962-01-23

    A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

  6. Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids (BPCA)

    PubMed Central

    Wiedemeier, Daniel B.; Lang, Susan Q.; Gierga, Merle; Abiven, Samuel; Bernasconi, Stefano M.; Früh-Green, Gretchen L.; Hajdas, Irka; Hanke, Ulrich M.; Hilf, Michael D.; McIntyre, Cameron P.; Scheider, Maximilian P. W.; Smittenberg, Rienk H.; Wacker, Lukas; Wiesenberg, Guido L. B.; Schmidt, Michael W. I.

    2016-01-01

    Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as char and soot. PyC is ubiquitous in the environment due to its long persistence, and its abundance might even increase with the projected increase in global wildfire activity and the continued burning of fossil fuel. PyC is also increasingly produced from the industrial pyrolysis of organic wastes, which yields charred soil amendments (biochar). Moreover, the emergence of nanotechnology may also result in the release of PyC-like compounds to the environment. It is thus a high priority to reliably detect, characterize and quantify these charred materials in order to investigate their environmental properties and to understand their role in the carbon cycle. Here, we present the benzene polycarboxylic acid (BPCA) method, which allows the simultaneous assessment of PyC's characteristics, quantity and isotopic composition (13C and 14C) on a molecular level. The method is applicable to a very wide range of environmental sample materials and detects PyC over a broad range of the combustion continuum, i.e., it is sensitive to slightly charred biomass as well as high temperature chars and soot. The BPCA protocol presented here is simple to employ, highly reproducible, as well as easily extendable and modifiable to specific requirements. It thus provides a versatile tool for the investigation of PyC in various disciplines, ranging from archeology and environmental forensics to biochar and carbon cycling research. PMID:27214064

  7. Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids (BPCA).

    PubMed

    Wiedemeier, Daniel B; Lang, Susan Q; Gierga, Merle; Abiven, Samuel; Bernasconi, Stefano M; Früh-Green, Gretchen L; Hajdas, Irka; Hanke, Ulrich M; Hilf, Michael D; McIntyre, Cameron P; Scheider, Maximilian P W; Smittenberg, Rienk H; Wacker, Lukas; Wiesenberg, Guido L B; Schmidt, Michael W I

    2016-01-01

    Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as char and soot. PyC is ubiquitous in the environment due to its long persistence, and its abundance might even increase with the projected increase in global wildfire activity and the continued burning of fossil fuel. PyC is also increasingly produced from the industrial pyrolysis of organic wastes, which yields charred soil amendments (biochar). Moreover, the emergence of nanotechnology may also result in the release of PyC-like compounds to the environment. It is thus a high priority to reliably detect, characterize and quantify these charred materials in order to investigate their environmental properties and to understand their role in the carbon cycle. Here, we present the benzene polycarboxylic acid (BPCA) method, which allows the simultaneous assessment of PyC's characteristics, quantity and isotopic composition ((13)C and (14)C) on a molecular level. The method is applicable to a very wide range of environmental sample materials and detects PyC over a broad range of the combustion continuum, i.e., it is sensitive to slightly charred biomass as well as high temperature chars and soot. The BPCA protocol presented here is simple to employ, highly reproducible, as well as easily extendable and modifiable to specific requirements. It thus provides a versatile tool for the investigation of PyC in various disciplines, ranging from archeology and environmental forensics to biochar and carbon cycling research. PMID:27214064

  8. Formation and preliminary in vitro evaluation of a zinc polycarboxylate cement reinforced with neat and acid-treated wollastonite fibers.

    PubMed

    Greish, Yaser E; Hamdan, Najwa M; El Maghraby, Hesham F

    2012-05-01

    Zinc polycarboxylate dental cement is known to form both molecular and mechanical bonds with native tooth materials. However, its relatively weak mechanical properties limit its applications. Wollastonite fibers, with different aspect ratios, were blended with ZnO, prior to its mixing with polyacrylic acid, at weight percentages up to 25%. Setting time, density, compressive strength, and Young's modulus of the formed composites were determined. Composition and morphology of the composites were determined by XRD, IR, and SEM before and after treatment in simulated body fluids. A slight delay in the setting time of the composites was observed. An overall improvement in the compressive strength and modulus of these composites was observed up to 5 wt % of wollastonites, followed by a decrease with increasing the proportion of wollastonite in the composites. Immersion of these composites in SBF solutions resulted in the formation of apatite deposits on the surfaces of the reinforcing fibers.

  9. Effects of acid diffusibility and affinity to cellulose on strength loss of polycarboxylic acid crosslinked fabrics.

    PubMed

    Ji, Bolin; Zhao, Cunyi; Yan, Kelu; Sun, Gang

    2016-06-25

    1,2,3,4-Butanetetracarboxylic acid (BTCA) imparts good anti-wrinkle property to cotton fabrics and results in significant strength loss due to cross-linking and acid degradation of cellulose simultaneously. However, benzophenone-3,3',4,4'- tetracarboxylic acid (BPTCA), an aromatic acid, crosslinks cellulose effectively but causes less strength loss to the products under similar conditions. The difference in damages to cellulose fibers was analyzed by using diffusibility and corresponding affinity of the acids to cellulose fibers, which were estimated by their molecular sizes and Hansen solubility parameters (HSP). Both experimental results and theoretical speculations revealed consistent agreement, indicating that smaller acid molecules could diffuse into cellulose fiber more rapidly and deeply, resulting in more acid degradation. Besides, the aliphatic acid such as BTCA has higher molecular affinity than BPTCA to cellulose, causing additional more degradation of cellulose. Both factors are potential reasons of the observed more severe tensile strength loss of the BTCA treated cotton fabrics. PMID:27083819

  10. Biosynthesis of alkyl lysophosphatidic acid by diacylglycerol kinases.

    PubMed

    Gellett, Amanda M; Kharel, Yugesh; Sunkara, Manjula; Morris, Andrew J; Lynch, Kevin R

    2012-06-15

    Lysophosphatidic acid (LPA) designates a family of bioactive phosphoglycerides that differ in the length and degree of saturation of their radyl chain. Additional diversity is provided by the linkage of the radyl chain to glycerol: acyl, alkyl, or alk-1-enyl. Acyl-LPAs are the predominate species in tissues and biological fluids. Alkyl-LPAs exhibit distinct pharmacodynamics at LPA receptors, potently drive platelet aggregation, and contribute to ovarian cancer aggressiveness. Multiple biosynthetic pathways exist for alkyl-LPA production. Herein we report that diacylglycerol kinases (DGKs) contribute to cell-associated alkyl-LPA production involving phosphorylation of 1-alkyl-2-acetyl glycerol and document the biosynthesis of alkyl-LPA by DGKs in SKOV-3 ovarian cancer cells, specifically identifying the contribution of DGKα. Concurrently, we discovered that treating SKOV-3 ovarian cancer cell with a sphingosine analog stimulates conversion of exogenous 1-alkyl-2-acetyl glycerol to alkyl-LPA, indicating that DGKα contributes significantly to the production of alkyl-LPA in SKOV-3 cells and identifying cross-talk between the sphingolipid and glycerol lipid pathways.

  11. Calcite growth-rate inhibition by fulvic acids isolated from Big Soda Lake, Nevada, USA, The Suwannee River, Georgia, USA and by polycarboxylic acids

    USGS Publications Warehouse

    Reddy, Michael M.; Leenheer, Jerry

    2011-01-01

    Calcite crystallization rates are characterized using a constant solution composition at 25°C, pH=8.5, and calcite supersaturation (Ω) of 4.5 in the absence and presence of fulvic acids isolated from Big Soda Lake, Nevada (BSLFA), and a fulvic acid from the Suwannee River, Georgia (SRFA). Rates are also measured in the presence and absence of low-molar mass, aliphatic-alicyclic polycarboxylic acids (PCA). BSLFA inhibits calcite crystal-growth rates with increasing BSLFA concentration, suggesting that BSLFA adsorbs at growth sites on the calcite crystal surface. Calcite growth morphology in the presence of BSLFA differed from growth in its absence, supporting an adsorption mechanism of calcite-growth inhibition by BSLFA. Calcite growth-rate inhibition by BSLFA is consistent with a model indicating that polycarboxylic acid molecules present in BSLFA adsorb at growth sites on the calcite crystal surface. In contrast to published results for an unfractionated SRFA, there is dramatic calcite growth inhibition (at a concentration of 1 mg/L) by a SRFA fraction eluted by pH 5 solution from XAD-8 resin, indicating that calcite growth-rate inhibition is related to specific SRFA component fractions. A cyclic PCA, 1, 2, 3, 4, 5, 6-cyclohexane hexacarboxylic acid (CHXHCA) is a strong calcite growth-rate inhibitor at concentrations less than 0.1 mg/L. Two other cyclic PCAs, 1, 1 cyclopentanedicarboxylic acid (CPDCA) and 1, 1 cyclobutanedicarboxylic acid (CBDCA) with the carboxylic acid groups attached to the same ring carbon atom, have no effect on calcite growth rates up to concentrations of 10 mg/L. Organic matter ad-sorbed from the air onto the seed crystals has no effect on the measured calcite crystal-growth rates.

  12. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218... 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2-...

  13. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218... 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2-...

  14. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218... 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2-...

  15. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218... 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2-...

  16. Alkyl hydroxybenzoic acid derivatives that inhibit HIV-1 protease dimerization.

    PubMed

    Flausino, O A; Dufau, L; Regasini, L O; Petrônio, M S; Silva, D H S; Rose, T; Bolzani, V S; Reboud-Ravaux, M

    2012-01-01

    The therapeutic potential of gallic acid and its derivatives as anti-cancer, antimicrobial and antiviral agents is well known. We have examined the mechanism by which natural gallic acid and newly synthesized gallic acid alkyl esters and related protocatechuic acid alkyl esters inhibit HIV-1 protease to compare the influence of the aromatic ring substitutions on inhibition. We used Zhang-Poorman's kinetic analysis and fluorescent probe binding to demonstrate that several gallic and protecatechuic acid alkyl esters inhibited HIV-1 protease by preventing the dimerization of this obligate homodimeric aspartic protease rather than targeting the active site. The tri-hydroxy substituted benzoic moiety in gallates was more favorable than the di-substituted one in protocatechuates. In both series, the type of inhibition, its mechanism and the inhibitory efficiency dramatically depended on the length of the alkyl chain: no inhibition with alkyl chains less than 8 carbon atoms long. Molecular dynamics simulations corroborated the kinetic data and propose that gallic esters are intercalated between the two N- and C-monomer ends. They complete the β-sheet and disrupt the dimeric enzyme. The best gallic ester (14 carbon atoms, K(id) of 320 nM) also inhibited the multi-mutated protease MDR-HM. These results will aid the rational design of future generations of non-peptide inhibitors of HIV-1 protease dimerization that inhibit multi-mutated proteases. Finally, our work suggests the wide use of gallic and protocatechuic alkyl esters to dissociate intermolecular β-sheets involved in protein-protein interactions.

  17. 40 CFR 721.10664 - Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., reaction products with alkenoic acid alkyl esters and diamine (generic). 721.10664 Section 721.10664... Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). (a... generically as alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and...

  18. 40 CFR 721.10664 - Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., reaction products with alkenoic acid alkyl esters and diamine (generic). 721.10664 Section 721.10664... Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). (a... generically as alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and...

  19. Acidity constants in methanol/water mixtures of polycarboxylic acids used in drug salt preparations. Potentiometric determination of aqueous pKa values of quetiapine formulated as hemifumarate.

    PubMed

    Garrido, Gemma; Ràfols, Clara; Bosch, Elisabeth

    2006-05-01

    The acidic dissociation constants in a number of methanol/water mixtures of mono and polycarboxylic acids commonly used in the preparation of drug salts were determined. These solvent mixtures are usually used to determine the pKa of drugs of low aqueous solubility. However, when these drugs are prepared in salt form, the acid-base equilibria of both the basic drug and the counter-anion are involved in the potentiometric titration curves. In these instances, the inclusion of the pKa of acids as constant values in the curve fitting provides easy computation of the drug pKa without the need of any previous step to get the free base. As an application example, the aqueous pKa values of the quetiapine formulated as hemifumarate (Seroquel) were estimated by extrapolation from the experimental pKa in several methanol/water mixtures, which were then calculated according to the suitable constants of fumaric acid. The estimated aqueous pKa values of quetiapine are compared with those directly obtained in aqueous solution by potentiometry and by capillary electrophoresis.

  20. Vapor pressures of substituted polycarboxylic acids are much lower than previously reported

    NASA Astrophysics Data System (ADS)

    Huisman, A. J.; Krieger, U. K.; Zuend, A.; Marcolli, C.; Peter, T.

    2013-07-01

    The partitioning of compounds between the aerosol and gas phase is a primary focus in the study of the formation and fate of secondary organic aerosol. We present measurements of the vapor pressure of 2-methylmalonic (isosuccinic) acid, 2-hydroxymalonic (tartronic) acid, 2-methylglutaric acid, 3-hydroxy-3-carboxy-glutaric (citric) acid and DL-2,3-dihydroxysuccinic (DL-tartaric) acid, which were obtained from the evaporation rate of supersaturated liquid particles levitated in an electrodynamic balance. Our measurements indicate that the pure component liquid vapor pressures at 298.15 K for tartronic, citric and tartaric acids are much lower than the same quantity that was derived from solid state measurements in the only other room temperature measurement of these materials (made by Booth et al., 2010). This strongly suggests that empirical correction terms in a recent vapor pressure estimation model to account for the inexplicably high vapor pressures of these and similar compounds should be revisited, and that due caution should be used when the estimated vapor pressures of these and similar compounds are used as inputs for other studies.

  1. 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...

  2. 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...

  3. Preparation of polyimides from mixtures of monomeric diamines and esters of polycarboxylic acids

    NASA Technical Reports Server (NTRS)

    Serafini, T. T.; Delvigs, P.; Lightsey, G. R. (Inventor)

    1973-01-01

    Polyimides having high thermal and oxidative stability are prepared by the reaction of a mixture of monomers comprising (1) a dialkyl or tetraalkyl ester of an aromatic tetracarboxylic acid; (2) an aromatic diamine; and (3) a monoalkyl or dialkyl ester of a dicarboxylic acid where in the ratio of a:b:c is n:(n+1):2, wherein n has a value from 1 to 20. The mixture of monomers is prepared in a 30 to 70 percent by weight solution of an organic solvent, a substrate impregnated with the solution and heated at 50 to 205 C to remove said solvent and form a low molecular weight prepolymer, and thereafter heated at 275 to 350 C to cure to a high molecular weight polyimide.

  4. Metal ion-catalyzed nucleic acid alkylation and fragmentation.

    PubMed

    Browne, Kenneth A

    2002-07-10

    Nucleic acid microarrays are a growing technology in which high densities of known sequences are attached to a substrate in known locations (addressed). Hybridization of complementary sequences leads to a detectable signal such as an electrical impulse or fluorescence. This combination of sequence addressing, hybridization, and detection increases the efficiency of a variety of genomic disciplines including those that profile genetic expression, search for single nucleotide polymorphisms (SNPs), or diagnose infectious diseases by sequencing portions of microbial or viral genomes. Incorporation of reporter molecules into nucleic acids is essential for the sensitive detection of minute amounts of nucleic acids on most types of microarrays. Furthermore, polynucleic acid size reduction increases hybridization because of increased diffusion rates and decreased competing secondary structure of the target nucleic acids. Typically, these reactions would be performed as two separate processes. An improvement to past techniques, termed labeling-during-cleavage (LDC), is presented in which DNA or RNA is alkylated with fluorescent tags and fragmented in the same reaction mixture. In model studies with 26 nucleotide-long RNA and DNA oligomers using ultraviolet/visible and fluorescence spectroscopies as well as high-pressure liquid chromatography and mass spectrometry, addition of both alkylating agents (5-(bromomethyl)fluorescein, 5- or 6-iodoacetamidofluorescein) and select metal ions (of 21 tested) to nucleic acids in aqueous solutions was critical for significant increases in both labeling and fragmentation, with >or=100-fold increases in alkylation possible relative to metal ion-free reactions. Lanthanide series metal ions, Pb(2+), and Zn(2+) were the most reactive ions in terms of catalyzing alkylation and fragmentation. While oligonucleotides were particularly susceptible to fragmentation at sites containing phosphorothioate moieties, labeling and cleavage reactions

  5. Complexation of amidated pectin with poly(itaconic acid) as a polycarboxylic polymer model compound.

    PubMed

    Nesic, Aleksandra R; Trifunovic, Snezana S; Grujic, Aleksandar S; Velickovic, Sava J; Antonovic, Dusan G

    2011-11-01

    Complexes based on amidated pectin (AP) and poly(itaconic acid) (PIA) were prepared by casting films from solutions of AP and PIA in different ratios with the pectin amount ranging from 10% to 90% by mass. The complexes were investigated by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TG). In all investigated ratios of AP/PIA glassy transparent films with a uniform structure were obtained. The results of elemental analysis confirmed the composition of the complexes, and FTIR spectroscopy has shown carboxylic and amide peak shifting, indicating complex formation between AP and PIA. Comparison of thermograms of AP/PIA films with different ratios of AP indicated that the increase of the amount of AP increases the thermal stability of the films by retarding the onset of the main degradation processes. PMID:21943549

  6. 40 CFR 721.10702 - Polyfluorinated alkyl thio polyacrylic acid-acrylamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl thio polyacrylic... Significant New Uses for Specific Chemical Substances § 721.10702 Polyfluorinated alkyl thio polyacrylic acid... substance identified generically as polyfluorinated alkyl thio polyacrylic acid-acrylamide (PMN P-11-534)...

  7. Alkyl esters of gallic acid as anticancer agents: a review.

    PubMed

    Locatelli, Claudriana; Filippin-Monteiro, Fabíola Branco; Creczynski-Pasa, Tânia Beatriz

    2013-02-01

    The current review presents the antitumoral properties of gallic acid and its ester derivatives. Numerous studies have indicated that the alkyl esters are more effective against tumor cell lines than gallic acid, and that this activity is related to their hydrophobic moiety. All related studies have shown that the antitumor activity is interconnected to the induction of apoptosis by different mechanisms and it depends on the cell type. The results presented in this review may help to emphasize that these compounds could be promising as a new alternative for the treatment of cancer, either alone or in combination with other antitumor drugs to potentiate their effects.

  8. Stable isotopic analysis of pyrogenic organic matter in soils by liquid chromatography-isotope-ratio mass spectrometry of benzene polycarboxylic acids.

    PubMed

    Yarnes, Christopher; Santos, Fernanda; Singh, Nimisha; Abiven, Samuel; Schmidt, Michael W I; Bird, Jeffrey A

    2011-12-30

    Pyrogenic organic matter (PyOM), the incomplete combustion product of organic materials, is considered stable in soils and represents a potentially important terrestrial sink for atmospheric carbon dioxide. One well-established method of measuring PyOM in the environment is as benzene polycarboxylic acids (BPCAs), a compound-specific method, which allows both qualitative and quantitative estimation of PyOM. Until now, stable isotope measurement of PyOM carbon involved measurement of the trimethylsilyl (TMS) or methyl (Me) polycarboxylic acid derivatives by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). However, BPCA derivatives can contain as much as 150% derivative carbon, necessitating post-analysis correction for the accurate measurement of δ¹³C values, leading to increased measurement error. Here, we describe a method for δ¹³C isotope ratio measurement and quantification of BPCAs from soil-derived PyOM, based on ion-exchange chromatography (IEC-IRMS). The reproducibility of the δ¹³C measurement of individual BPCAs by IEC-IRMS was better than 0.35‰ (1σ). The δ¹³C-BPCA analysis of PyOM in soils, including at natural and artificially enriched ¹³C-abundance, produced accurate and precise δ¹³C measurements. Analysis of samples that differed in δ¹³C by as much as 900‰ revealed carryover of <1‰ between samples. The weighted sum of individual δ¹³C-BPCA measurements was correlated with previous isotopic measurements of whole PyOM, providing complementary information for bulk isotopic measurements. We discuss potential applications of δ¹³C-BPCA measurements, including the study of turnover rates of PyOM in soils and the partitioning of PyOM sources based on photosynthetic pathways. PMID:22468329

  9. Alkylating potency of nitrosated amino acids and peptides.

    PubMed

    Shephard, S E; Meier, I; Lutz, W K

    1991-01-01

    The alkylating potency of unstable N-nitrosamino acids and N-nitrosopeptides was investigated in vitro using 4-(para-nitrobenzyl)pyridine (NBP) as nucleophile. Of the amino acids, Met and those with an aromatic side chain were the most potent. The relative overall alkylating potency was 23:10:5:4:2:1: for Trp, Met, His, Tyr, Phe and Gly, respectively. The homo-dipeptides were much more potent than the amino acids, with relative potencies of 400:110:100:8:3:1, for Trp-Trp, Tyr-Tyr, Met-Met, Asp-Asp, Phe-Phe and Gly, respectively. In the one-phase reaction system (in which NBP is already present during the nitrosation reaction at acidic pH), all amino acids tested showed a second-order reaction for nitrite. In the two-phase system (in which NBP is added only after bringing the nitrosation reaction mixture to neutrality), all amino acids tested except one again showed a second-order reaction for nitrite (Phe, His, Asp and the dipeptide artificial sweetener aspartame); only Met under these conditions had a reaction order of one for nitrite. This could mean that nitrosation of the side chain of Met produces a second N-nitroso product which is relatively stable in acid but reacts with NBP under neutral conditions. In the human stomach, this side-chain nitrosation might become more important than the reactions at the primary amino group, firstly because of the greater stability of the product(s) in acid and secondly because of the first-order reaction rate for nitrite.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Synthesis and Characterization of Surface Grafted Poly(N-isopropylacrylamide) and Poly(Carboxylic Acid)– Iron Particles via Atom Transfer Radical Polymerization for Biomedical Applications

    PubMed Central

    Sutrisno, Joko; Fuchs, Alan; Evrensel, Cahit

    2014-01-01

    This research relates to the preparation and characterization of surface grafted poly(N-isopropylacrylamide) and poly(carboxylic acid)–micron-size iron particles via atom transfer radical polymerization (ATRP). The surface grafted polymers–iron particles result in multifunctional materials which can be used in biomedical applications. The functionalities consist of cell targeting, imaging, drug delivery, and immunological response. The multifunctional materials are synthesized in two steps. First, surface grafting is used to place polymer molecules on the iron particles surface. The second step, is conjugation of the bio-molecules onto the polymer backbone. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy were used to confirm the presence of polymers on the iron particles. The thickness of the grafted polymers and glass transition temperature of the surface grafted polymers were determined by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The covalent bond between grafted polymers and iron particles caused higher glass transition temperature as compared with non-grafted polymers. The ability to target the bio-molecule and provide fluorescent imaging was simulated by conjugation of rat immunoglobulin and fluorescein isothiocyanate (FITC) labeled anti-rat. The fluorescence intensity was determined using flow cytometry and conjugated IgG-FITC anti-rat on iron particles which was imaged using a fluorescence microscopy. PMID:25382869

  11. Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids.

    PubMed

    Fu, Ming-Chen; Shang, Rui; Cheng, Wan-Min; Fu, Yao

    2015-07-27

    A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts. PMID:26150397

  12. Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids.

    PubMed

    Fu, Ming-Chen; Shang, Rui; Cheng, Wan-Min; Fu, Yao

    2015-07-27

    A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts.

  13. 40 CFR 721.6100 - Phosphoric acid, C6-12-alkyl esters, compounds with 2-(dibutylamino) ethanol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phosphoric acid, C6-12-alkyl esters... Significant New Uses for Specific Chemical Substances § 721.6100 Phosphoric acid, C6-12-alkyl esters... reporting. (1) The chemical substances identified as phosphoric acid, C6-12-alkyl esters, compounds with...

  14. 40 CFR 721.6100 - Phosphoric acid, C6-12-alkyl esters, compounds with 2-(dibutylamino) ethanol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphoric acid, C6-12-alkyl esters... Significant New Uses for Specific Chemical Substances § 721.6100 Phosphoric acid, C6-12-alkyl esters... reporting. (1) The chemical substances identified as phosphoric acid, C6-12-alkyl esters, compounds with...

  15. 40 CFR 721.6100 - Phosphoric acid, C6-12-alkyl esters, compounds with 2-(dibutylamino) ethanol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphoric acid, C6-12-alkyl esters... Significant New Uses for Specific Chemical Substances § 721.6100 Phosphoric acid, C6-12-alkyl esters... reporting. (1) The chemical substances identified as phosphoric acid, C6-12-alkyl esters, compounds with...

  16. 40 CFR 721.6100 - Phosphoric acid, C6-12-alkyl esters, compounds with 2-(dibutylamino) ethanol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, C6-12-alkyl esters... Significant New Uses for Specific Chemical Substances § 721.6100 Phosphoric acid, C6-12-alkyl esters... reporting. (1) The chemical substances identified as phosphoric acid, C6-12-alkyl esters, compounds with...

  17. 40 CFR 721.6100 - Phosphoric acid, C6-12-alkyl esters, compounds with 2-(dibutylamino) ethanol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid, C6-12-alkyl esters... Significant New Uses for Specific Chemical Substances § 721.6100 Phosphoric acid, C6-12-alkyl esters... reporting. (1) The chemical substances identified as phosphoric acid, C6-12-alkyl esters, compounds with...

  18. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted alkyl aminomethylene polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.7785 Substituted alkyl aminomethylene...

  19. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic 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 alkyl aminomethylene polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.7785 Substituted alkyl aminomethylene...

  20. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted alkyl aminomethylene polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.7785 Substituted alkyl aminomethylene...

  1. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkyl aminomethylene polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.7785 Substituted alkyl aminomethylene...

  2. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic 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 alkyl aminomethylene polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.7785 Substituted alkyl aminomethylene...

  3. Manganese-Mediated C-H Alkylation of Unbiased Arenes Using Alkylboronic Acids.

    PubMed

    Castro, Susana; Fernández, Juan J; Fañanás, Francisco J; Vicente, Rubén; Rodríguez, Félix

    2016-06-27

    The alkylation of arenes is an essential synthetic step of interest not only from the academic point of view but also in the bulk chemical industry. Despite its limitations, the Friedel-Crafts reaction is still the method of choice for most of the arene alkylation processes. Thus, the development of new strategies to synthesize alkyl arenes is a highly desirable goal, and herein, we present an alternative method to those conventional reactions. Particularly, a simple protocol for the direct C-H alkylation of unbiased arenes with alkylboronic acids in the presence of Mn(OAc)3 ⋅2H2 O is reported. Primary or secondary unactivated alkylboronic acids served as alkylating agents for the direct functionalization of representative polyaromatic hydrocarbons (PAHs) or benzene. The results are consistent with a free-radical mechanism. PMID:27124250

  4. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). (a... generically as naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted...

  5. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). (a... generically as naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted...

  6. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). (a... generically as naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted...

  7. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction products of secondary alkyl... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... substances identified generically as reaction products of secondary alkyl amines with a...

  8. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction products of secondary alkyl... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... substances identified generically as reaction products of secondary alkyl amines with a...

  9. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction products of secondary alkyl... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... substances identified generically as reaction products of secondary alkyl amines with a...

  10. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reaction products of secondary alkyl... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... substances identified generically as reaction products of secondary alkyl amines with a...

  11. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction products of secondary alkyl... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... substances identified generically as reaction products of secondary alkyl amines with a...

  12. Diarmed (adamantyl/alkyl) surfactants from nitrilotriacetic acid.

    PubMed

    Trillo, Juan V; Vázquez Tato, José; Jover, Aida; de Frutos, Santiago; Soto, Victor H; Galantini, Luciano; Meijide, Francisco

    2014-11-01

    The compounds presented here constitute a clear example of molecular biomimetics as their design is inspired on the structure and properties of natural phospholipids. Thus novel double-armed surfactants have been obtained in which nitrilotriacetic acid plays the role of glycerol in phospholipids. The hydrophobic arms are linked to the head group through amide bonds (which is also the case of sphingomyelin): (R1NHCOCH2)(R2NHCOCH2)NCH2CO2H (R1 being CH3(CH2)11, CH3(CH2)17, CH3(CH2)7CHCH(CH2)8, and adamantyl, and R2=adamantyl). The dependence of the surface tension with concentration shows the typical profile of surfactants since a breaking point, which corresponds to the critical aggregation concentration (cac), is observed in all cases. The cac of these diarmed derivatives are about 1-3 orders of magnitude lower than those of classical monoalkyl derivatives used as reference compounds. In contrast to conventional surfactants, reversed trends in cac values and molecular areas at the solution-air interface have been observed. This anomalous behavior is tied to the structure of the surfactants and suggests that long and flexible alkyl chains should self-coil previous to the aggregation or adsorption phenomena. Above cac all compounds form large aggregates, globular in shape, which tend to associate forming giant aggregates. PMID:25465758

  13. Photochemical alkylation of inorganic selenium in the presence of low molecular weight organic acids.

    PubMed

    Guo, Xuming; Sturgeon, Ralph E; Mester, Zoltán; Gardner, Graeme J

    2003-12-15

    Using a flow-through photochemical reactor and a low pressure mercury lamp as a UV source, alkyl selenium species are formed from inorganic selenium(IV) in the presence of low molecular weight organic acids (LMW acids). The volatile alkyl Se species were cryogenically trapped and identified by GC-MS and GC-ICP-MS. In the presence of formic, acetic, propionic and malonic acids, inorganic selenium(IV) is converted by UV irradiation to volatile selenium hydride and carbonyl, dimethylselenide and diethylselenide, respectively. Se(IV) was successfully removed from contaminated agricultural drainage waters (California, U.S.A.) using a batch photoreactor system Se. Photochemical alkylation may thus offer a promising means of converting toxic selenium salts, present in contaminated water, to less toxic dimethylselenide. The LMW acids and photochemical alkylation process may also be key to understanding the source of atmospheric selenium and are likely involved in its mobility in the natural anaerobic environment.

  14. Polycyclic Aromatic Acids Are Primary Metabolites of Alkyl-PAHs-A Case Study with Nereis diversicolor.

    PubMed

    Malmquist, Linus M V; Selck, Henriette; Jørgensen, Kåre B; Christensen, Jan H

    2015-05-01

    Although concentrations of alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) in oil-contaminated sediments are higher than those of unsubstituted PAHs, only little attention has been given to metabolism and ecotoxicity of alkyl-PAHs. In this study we demonstrated that metabolism of alkyl-PAHs primarily forms polycyclic aromatic acids (PAAs). We generalize this to other alkyl-PAHs, based on literature and the present study of the metabolism of 1-methylphenanthrene, 3,6-dimethylphenanthrene, and 1-, 2-, 3-, and 6-methylchrysene related to their unsubstituted parent PAHs. Also, we observed that body burdens and production of PAAs was related to the position of the methyl group, showing the same isomer specific preferences as for microbial degradation of alkyl-PAHs. We detected a high production of PAAs, and larger metabolism of alkyl-PAHs than their unsubstituted parent PAHs. We therefore propose that carboxylic acid metabolites of alkyl-PAHs have the potential of constituting a new class of contaminants in marine waters that needs attention in relation to ecological risk assessments.

  15. Oligonucleoside alkyl or arylphosphonate derivatives capable of crosslinking with or cleaving nucleic acids

    DOEpatents

    Miller, P.S.; Ts'o, P.O.P.

    1999-06-15

    A composition for inactivating a target nucleic acid which comprises an oligonucleoside alkyl or arylphosphonate analogue which is complementary to the sequence of the target nucleic acid is provided. It includes a functional group which reacts with the target nucleic acid to render the target nucleic acid inactive or nonfunctional. 16 figs.

  16. Oligonucleoside alkyl or arylphosphonate derivatives capable of crosslinking with or cleaving nucleic acids

    DOEpatents

    Miller, Paul S.; Ts'o, Paul O.P.

    1999-06-15

    A composition for inactivating a target nucleic acid which comprises an oligonucleoside alkyl or arylphosphonate analogue which is complementary to the sequence of the target nucleic acid and includes a functional group which reacts with the target nucleic acid to render the target nucleic acid inactive or nonfunctional.

  17. Ambient cure polyimide foams prepared from aromatic polyisocyanates, aromatic polycarboxylic compounds, furfuryl alcohol, and a strong inorganic acid

    NASA Technical Reports Server (NTRS)

    Sawko, Paul M. (Inventor); Riccitiello, Salvatore R. (Inventor); Hamermesh, Charles L. (Inventor)

    1980-01-01

    Flame and temperature resistant polyimide foams are prepared by the reaction of an aromatic dianhydride, e.g., pyromellitic dianhydride, with an aromatic polyisocyanate, e.g., polymethylene polyphenylisocyanate (PAPI) in the presence of an inorganic acid and a lower molecular weight alcohol, e.g., dilute sulfuric acid or phosphoric acid and furfuryl alcohol. The exothermic reaction between the acid and the alcohol provides the heat necessary for the other reactants to polymerize without the application of any external heat. Such mixtures, therefore, are ideally suited for in situ foam formation, especially where the application of heat is not practical or possible.

  18. Reaction between alkyl isocyanides and isopropylidene Meldrum's acid in the presence of bidentate nucleophiles.

    PubMed

    Yavari, Issa; Sabbaghan, Maryam; Hossaini, Zinatossadat

    2007-02-01

    The reaction between alkyl isocyanides and isopropylidene Meldrum's acid in the presence of 1,2-ethanediol leads to N (1)-(alkyl)-2-(5,7-dioxo-1,4-dioxepane-6-yl)-2-methylpropanamides. 1,3-Propanediol or 1,4-butanediol produce hydroxyalkyl 1-(tert-butyl)-4,4-dimethyl-2,5-dioxo-3-pyrrolidinecarboxylates. When the reaction was performed in the presence of catechol, bis(2-hydroxyphenyl) 2-[2-(tert-butylamino)-1,1-dimethyl-2-oxoethyl]malonate was obtained. 2-Aminophenols react with alkyl isocyanides in the presence of isopropylidene Meldrum's acid to produce 1-alkyl-N (3)-(2-hydroxyaryl)-4,4-dimethyl-2,5-dioxo-3-pyrrolidinecarboxamides in good yields.

  19. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical... acid, mono-C9-11-alkyl esters, sodium salts (PMN P-01-149; CAS No. 84501-49-5) is subject to...

  20. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical... acid, mono-C9-11-alkyl esters, sodium salts (PMN P-01-149; CAS No. 84501-49-5) is subject to...

  1. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical... acid, mono-C9-11-alkyl esters, sodium salts (PMN P-01-149; CAS No. 84501-49-5) is subject to...

  2. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical... acid, mono-C9-11-alkyl esters, sodium salts (PMN P-01-149; CAS No. 84501-49-5) is subject to...

  3. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical... acid, mono-C9-11-alkyl esters, sodium salts (PMN P-01-149; CAS No. 84501-49-5) is subject to...

  4. A novel star-shaped poly(carboxylic acid) for resin-modified glass-ionomer restoratives.

    PubMed

    Weng, Y; Howard, L; Xie, D

    2014-07-01

    We have developed a novel glass-ionomer cement (GIC) system composed of photo-curable star-shaped poly(acrylic acid-co-itaconic acid)s. These polyacids were synthesized via a chain-transfer radical polymerization using a newly synthesized multi-arm chain-transfer agent. The star-shaped polyacids showed significantly lower viscosities in water as compared to the linear polyacids. Due to the lower viscosities, the molecular weight (MW) of the polyacids can be significantly increased for enhancing the mechanical strengths while keeping the ease of mixing and handling. The effects of MW, GM-tethering ratio, P/L ratio, and aging on the compressive properties of the experimental cements were significant. The light-cured experimental cements showed significantly improved mechanical strengths i.e. 49% in yield strength, 41% in modulus, 25% in CS, 20% in DTS, and 36% in FS, higher than commercial Fuji II LC. After aging in water for 1 month, the compressive strength of the novel light-cured experimental cement reached 343 MPa, which was 34% and 42% higher than Fuji II and Fuji II LC, respectively. This one-month aged experimental cement was also 23% higher than itself after one day aging, indicating that aging in water can significantly enhance salt-bridge formation for this novel star-shaped polyacid-comprised GIC.

  5. A novel star-shaped poly(carboxylic acid) for resin-modified glass-ionomer restoratives.

    PubMed

    Weng, Y; Howard, L; Xie, D

    2014-07-01

    We have developed a novel glass-ionomer cement (GIC) system composed of photo-curable star-shaped poly(acrylic acid-co-itaconic acid)s. These polyacids were synthesized via a chain-transfer radical polymerization using a newly synthesized multi-arm chain-transfer agent. The star-shaped polyacids showed significantly lower viscosities in water as compared to the linear polyacids. Due to the lower viscosities, the molecular weight (MW) of the polyacids can be significantly increased for enhancing the mechanical strengths while keeping the ease of mixing and handling. The effects of MW, GM-tethering ratio, P/L ratio, and aging on the compressive properties of the experimental cements were significant. The light-cured experimental cements showed significantly improved mechanical strengths i.e. 49% in yield strength, 41% in modulus, 25% in CS, 20% in DTS, and 36% in FS, higher than commercial Fuji II LC. After aging in water for 1 month, the compressive strength of the novel light-cured experimental cement reached 343 MPa, which was 34% and 42% higher than Fuji II and Fuji II LC, respectively. This one-month aged experimental cement was also 23% higher than itself after one day aging, indicating that aging in water can significantly enhance salt-bridge formation for this novel star-shaped polyacid-comprised GIC. PMID:24865692

  6. Alkyl substituent effects on gas-phase acidities - The influence of hybridization.

    NASA Technical Reports Server (NTRS)

    Brauman, J. I.; Blair, L. K.

    1971-01-01

    Exploration of the effect on acidity of alkyl groups bonded to trigonal and digonal carbon. Some results on the relative acidities of toluene and p-xylene, and acetylene and substitute acetylenes, as determined by ion cyclotron resonance (icr) spectroscopy, are described. Some limitations of the CNDO/2 calculation method are discussed.

  7. The acid free asymmetric intermolecular α-alkylation of aldehydes in fluorinated alcohols.

    PubMed

    Xiao, Jian; Zhao, Kai; Loh, Teck-Peng

    2012-04-11

    The acid free asymmetric intermolecular α-alkylation of aldehydes with alcohols has been discovered using trifluoroethanol as solvent. This unprecedented system affords the enantioenriched functionalized primary alcohols (after NaBH(4) reduction) in high yields and good to excellent enantioselectivities with wide substrate scope in the absence of any acid additive.

  8. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium for a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate or hydroxide thereby stripping uranium from the organic extractant into the stripping solution. The resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  9. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium from a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant to and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate, nonsaturated in uranium. The uranium is stripped from, the organic extractant into the stripping solution, and the resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  10. Enhanced Synthesis of Alkyl Amino Acids in Miller's 1958 H2S Experiment

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, James P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Stanley Miller's 1958 H2S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH4), ammonia (NH3), carbon dioxide (CO2), and hydrogen sulfide (H2S) produced several alkyl amino acids, including the alpha-, beta-, and gamma-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H2S, aspariic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H2S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H2S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth.

  11. Enhanced synthesis of alkyl amino acids in Miller's 1958 H2S experiment.

    PubMed

    Parker, Eric T; Cleaves, H James; Callahan, Michael P; Dworkin, Jason P; Glavin, Daniel P; Lazcano, Antonio; Bada, Jeffrey L

    2011-12-01

    Stanley Miller's 1958 H(2)S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH(4)), ammonia (NH(3)), carbon dioxide (CO(2)), and hydrogen sulfide (H(2)S) produced several alkyl amino acids, including the α-, β-, and γ-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H(2)S, aspartic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H(2)S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H(2)S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth. PMID:22139514

  12. 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.

  13. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases; Part 1: alkyl halide alkylations.

    PubMed

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim A

    2013-10-01

    Alkylations of chiral or achiral Ni(II) complexes of glycine Schiff bases constitute a landmark in the development of practical methodology for asymmetric synthesis of α-amino acids. Straightforward, easy preparation as well as high reactivity of these Ni(II) complexes render them ready available and inexpensive glycine equivalents for preparing a wide variety of α-amino acids, in particular on a relatively large scale. In the case of Ni(II) complexes containing benzylproline moiety as a chiral auxiliary, their alkylation proceeds with high thermodynamically controlled diastereoselectivity. Similar type of Ni(II) complexes derived from alanine can also be used for alkylation providing convenient access to quaternary, α,α-disubstituted α-amino acids. Achiral type of Ni(II) complexes can be prepared from picolinic acid or via recently developed modular approach using simple secondary or primary amines. These Ni(II) complexes can be easily mono/bis-alkylated under homogeneous or phase-transfer catalysis conditions. Origin of diastereo-/enantioselectivity in the alkylations reactions, aspects of practicality, generality and limitations of this methodology is critically discussed.

  14. DNA-damaging disinfection byproducts: alkylation mechanism of mutagenic mucohalic acids.

    PubMed

    Gómez-Bombarelli, Rafael; González-Pérez, Marina; Arenas-Valgañón, Jorge; Céspedes-Camacho, Isaac Fabián; Calle, Emilio; Casado, Julio

    2011-10-15

    Hydroxyhalofuranones form a group of genotoxic disinfection byproduct (DBP) of increasing interest. Among them, mucohalic acids (3,4-dihalo-5-hydroxyfuran-2(5H)-one, MXA) are known mutagens that react with nucleotides, affording etheno, oxaloetheno, and halopropenal derivatives. Mucohalic acids have also found use in organic synthesis due to their high functionalization. In this work, the alkylation kinetics of mucochloric and mucobromic acids with model nucleophiles aniline and NBP has been studied experimentally. Also, the alkylation mechanism of nucleosides by MXA has been studied in silico. The results described allow us to reach the following conclusions: (i) based on the kinetic and computational evidence obtained, a reaction mechanism was proposed, in which MXA react directly with amino groups in nucleotides, preferentially attacking the exocyclic amino groups over the endocyclic aromatic nitrogen atoms; (ii) the suggested mechanism is in agreement with both the product distribution observed experimentally and the mutational pattern of MXA; (iii) the limiting step in the alkylation reaction is addition to the carbonyl group, subsequent steps occurring rapidly; and (iv) mucoxyhalic acids, the hydrolysis products of MXA, play no role in the alkylation reaction by MXA.

  15. Friedel-crafts alkylation of benzene by normal omega-chloroalkanoic acids and their methyl esters and nitriles

    SciTech Connect

    Zakharkin, L.I.; Anikina, E.V.

    1987-08-20

    In the Friedel-Crafts alkylation of benzene by normal 1-haloalkanes with three or more carbon atoms a mixture of phenylalkanes forms, due to isomerization of the alkyl chain and migration of a hydrogen atoms. Under analogous conditions the alkylation of benzene by omega-chloroalkanoic acids, Cl(CH/sub 2/)/sub n/COOH, and omega-bromoalkanonitriles proceeds with isomerization of the alkyl chain, but beginning only with 6-chlorohexanoic acid and 6-bromohexanonitrile. Such a difference in the behavior of these halogen derivatives has not received a convincing explanation, although the mechanism of Friedel-Crafts alkylation of benzene should be the same in the two cases. For a better understanding of this difference, this work presents a systematic study of benzene alkylation by 4-chlorobutyric, 5-chlorovaleric, 6-chlorohexanoic, and 7-chloroheptanoic acids and their methyl esters and nitriles, and by ..gamma..-butyro- and delta-valerolactones. The catalyst was crystalline AlCl/sub 3/ twice sublimed from Mg. For comparison, alkylation with the respective 1-chloroalkanes was carried out. In the alkylation of benzene by omega-chloroalkanoic acids Cl(CH/sub 2/)/sub n/COOH (where n = 3-6) and their methyl esters and nitriles, in the presence of AlCl/sub 3/, the degree of isomerization of the alkyl chain is less than with the corresponding 1-chloroalkanes, depending on the increase in electron acceptor activity in the sequence HOOC- > CH/sub 3/OCO- > CN-.

  16. The roles of polycarboxylates in Cr(VI)/sulfite reaction system: Involvement of reactive oxygen species and intramolecular electron transfer.

    PubMed

    Jiang, Bo; Wang, Xianli; Liu, Yukun; Wang, Zhaohui; Zheng, Jingtang; Wu, Mingbo

    2016-03-01

    In this study, the effects of polycarboxylates on both Cr(VI) reduction and S(IV) consumption in Cr(VI)/S(IV) system was investigated in acidic solution. Under aerobic condition, the productions of reactive oxygen species (ROS), i.e., SO4(-) and OH, have been confirmed in S(IV) reducing Cr(VI) process by using electron spin resonance and fluorescence spectrum techniques, leading to the excess consumption of S(IV). However, when polycarboxylates (oxalic, citric, malic and tartaric acid) were present in Cr(VI)/S(IV) system, the affinity of polycarboxylates to CrSO6(2-) can greatly promote the reduction of Cr(VI) via expanding the coordination of Cr(VI) species from tetrahedron to hexahedron. Besides, as alternatives to S(IV), these polycarboxylates can also act as electron donors for Cr(VI) reduction via intramolecular electron transfer reaction, which is dependent on the energies of the highest occupied molecular orbital of these polycarboxylates. Notably, the variant electron donating capacity of these polycarboxylates resulted in different yield of ROS and therefore the oxidation efficiencies of other pollutants, e.g., rhodamine B and As(III). Generally, this study does not only shed light on the mechanism of S(IV) reducing Cr(VI) process mediated by polycarboxylates, but also provides an escalated, cost-effective and green strategy for the remediation of Cr(VI) using sulfite as a reductant. PMID:26610099

  17. Alkyl protocatechuates as novel urinary biomarkers of exposure to p-hydroxybenzoic acid esters (parabens).

    PubMed

    Wang, Lei; Kannan, Kurunthachalam

    2013-09-01

    Human exposure to p-hydroxybenzoic acid esters (parabens) is a concern, owing to adverse health effects of these compounds. Parabens are metabolized and eliminated from the human bodies within a few hours of exposure. In this study, for the first time, methyl- and ethyl-protocatechuates (OH-MeP and OH-EtP) and their parent compounds, methyl- (MeP) and ethyl-parabens (EtP), were determined in urine samples collected from U.S. children and adults. Alkyl protocatechuates were found in almost all urine samples, with median concentrations of 11.8 (OH-MeP) and 2.90ng/mL (OH-EtP) in adults, and 5.43 (OH-MeP) and 0.85ng/mL (OH-EtP) in children. In adults, the concentrations of urinary OH-MeP and OH-EtP were higher than the corresponding concentrations of MeP and EtP. Significant correlation between OH-MeP/OH-EtP and MeP/EtP was observed. This is the first report to document hydroxylation of parabens in humans, and to propose hydroxylated metabolites (i.e., alkyl protocatechuates) as alternative biomarkers of exposure to parabens in human biomonitoring studies. The rates of transformation of parabens between children and adults appeared to be different, as evidenced from the slopes of regression between alkyl protocatechuates and parabens. In addition to alkyl protocatechuates, hydroxybenzoic acid (4-HB) and 3,4-dihydroxybenzoic acid (3,4-DHB) were found at considerable levels in the urine samples. The occurrence of a significant proportion of alkyl protocatechuates and 3,4-DHB suggests the need for inclusion of these derivatives in accurate estimation of human exposure to parabens and in epidemiological studies that associate paraben exposure to health outcomes in populations.

  18. Mechanism of Boron-Catalyzed N-Alkylation of Amines with Carboxylic Acids.

    PubMed

    Zhang, Qi; Fu, Ming-Chen; Yu, Hai-Zhu; Fu, Yao

    2016-08-01

    Mechanistic study has been carried out on the B(C6F5)3-catalyzed amine alkylation with carboxylic acid. The reaction includes acid-amine condensation and amide reduction steps. In condensation step, the catalyst-free mechanism is found to be more favorable than the B(C6F5)3-catalyzed mechanism, because the automatic formation of the stable B(C6F5)3-amine complex deactivates the catalyst in the latter case. Meanwhile, the catalyst-free condensation is constituted by nucleophilic attack and the indirect H2O-elimination (with acid acting as proton shuttle) steps. After that, the amide reduction undergoes a Lewis acid (B(C6F5)3)-catalyzed mechanism rather than a Brønsted acid (B(C6F5)3-coordinated HCOOH)-catalyzed one. The B(C6F5)3)-catalyzed reduction includes twice silyl-hydride transfer steps, while the first silyl transfer is the rate-determining step of the overall alkylation catalytic cycle. The above condensation-reduction mechanism is supported by control experiments (on both temperature and substrates). Meanwhile, the predicted chemoselectivity is consistent with the predominant formation of the alkylation product (over disilyl acetal product). PMID:27441997

  19. Ignition Delays of Alkyl Thiophosphites with White and Red Fuming Nitric Acids Within Temperature Range 80 to -105 F

    NASA Technical Reports Server (NTRS)

    Miller, Riley O; Ladanyi, Dezso J

    1953-01-01

    Ignition delays of alkyl thiophosphites were obtained in a modified open-cup apparatus and a small-scale rocket engine apparatus. At -40 F, mixed alkyl thiophosphites gave short delays with white fuming nitric acid containing 2 percent water and red fuming nitric acids of widely varying compositions. At -40 F and higher, triethyl trithiophosphite blended with as much as 40 percent n-heptane gave satisfactory self-igniting properties at temperatures as low as -76 F.

  20. Effects of the addition of dimer acid alkyl esters on the properties of ethyl cellulose.

    PubMed

    Lee, Sangjun; Ko, Kwang-Hwan; Shin, Jihoon; Kim, Nam-Kyun; Kim, Young-Wun; Kim, Joon-Seop

    2015-05-01

    In this study, we synthesized dimer acid (DA) esters, having short to long alkyl chains, (DA-Cn) by the Diels-Alder reaction and subsequent esterification reaction of fatty acids that were prepared by the hydrolysis of waste vegetable oil. It was found that the DA-Cn were thermally more stable than common petroleum-based plasticizer DOP. When the DOP, DA, or DA-Cn with short alkyl chains were added to ethyl cellulose (EC), the optical clarity and SEM images of the samples showed their good miscibility with those additives in a micro-scale. It was also found that the rubbery modulus of the EC decreased with increasing amount of additives; the type of the additives did not affect the rates of the decrease in the rubbery modulus. The main transition temperatures of the EC containing either DA or DA-C1 or DA-C4 decreased with increasing amounts of those additives and were comparable to that of the DOP-containing EC. The above findings suggested that the DA and its esters with short alkyl chains could act as effective plasticizer and, thus, could be used instead of the DOP. In addition, the results obtained from tensile testing and leaching experiments implied that the DA might be better plasticizer than the DA-C1 and DA-C4, at least in some cases, because of hydrogen-bonding with the EC.

  1. Raman Scattering Sensor for Control of the Acid Alkylation Process in Gasoline Production

    SciTech Connect

    Uibel, Rory, H.; Smith, Lee M.; Benner, Robert, E.

    2006-04-19

    Gasoline refineries utilize a process called acid alkylation to increase the octane rating of blended gasoline, and this is the single most expensive process in the refinery. For process efficiency and safety reasons, the sulfuric acid can only be used while it is in the concentration range of 98 to 86 %. The conventional technique to monitor the acid concentration is time consuming and is typically conducted only a few times per day. This results in running higher acid concentrations than they would like to ensure that the process proceeds uninterrupted. Maintaining an excessively high acid concentration costs the refineries millions of dollars each year. Using SBIR funding, Process Instruments Inc. has developed an inline sensor for real time monitoring of acid concentrations in gasoline refinery alkylation units. Real time data was then collected over time from the instrument and its responses were matched up with the laboratory analysis. A model was then developed to correlate the laboratory acid values to the Raman signal that is transmitted back to the instrument from the process stream. The instrument was then used to demonstrate that it could create real-time predictions of the acid concentrations. The results from this test showed that the instrument could accurately predict the acid concentrations to within ~0.15% acid strength, and this level of prediction proved to be similar or better then the laboratory analysis. By utilizing a sensor for process monitoring the most economic acid concentrations can be maintained. A single smaller refinery (50,000 barrels/day) estimates that they should save over $120,000/year, with larger refineries saving considerably more.

  2. Metallaphotoredox-catalysed sp(3)-sp(3) cross-coupling of carboxylic acids with alkyl halides.

    PubMed

    Johnston, Craig P; Smith, Russell T; Allmendinger, Simon; MacMillan, David W C

    2016-08-18

    In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp(3)-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp(2)-hybridized species, the development of methods for sp(3)-sp(3) bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp(3)-sp(3) bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step- and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp(3)-sp(3) coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp(3)-sp(3) bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox

  3. Metallaphotoredox-catalysed sp(3)-sp(3) cross-coupling of carboxylic acids with alkyl halides.

    PubMed

    Johnston, Craig P; Smith, Russell T; Allmendinger, Simon; MacMillan, David W C

    2016-08-18

    In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp(3)-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp(2)-hybridized species, the development of methods for sp(3)-sp(3) bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp(3)-sp(3) bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step- and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp(3)-sp(3) coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp(3)-sp(3) bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox

  4. Metallaphotoredox-catalysed sp3-sp3 cross-coupling of carboxylic acids with alkyl halides

    NASA Astrophysics Data System (ADS)

    Johnston, Craig P.; Smith, Russell T.; Allmendinger, Simon; MacMillan, David W. C.

    2016-08-01

    In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp3-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp2-hybridized species, the development of methods for sp3-sp3 bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp3-sp3 bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step- and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp3-sp3 coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp3-sp3 bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox protocol is suitable for

  5. Enhanced antiamyloidal activity of hydroxy cinnamic acids by enzymatic esterification with alkyl alcohols.

    PubMed

    Kondo, Hazuki; Sugiyama, Haruka; Katayama, Shigeru; Nakamura, Soichiro

    2014-01-01

    Lipophilic derivatives of hydroxyl cinnamic acids (HCAs) including caffeic acid (CA), ferulic acid, sinapic acid (SA), and chlorogenic acid were synthesized by esterification with butanol, octanol, or hexadecanol catalyzed by the lipase from Candida antarctica to investigate the effect of lipophilicity on their antiamyloidal activity assessed by the inhibitory activities toward fibrillization of amyloid β (Aβ) peptide. Among them, CA showed the highest activity at 50 μM, reducing the amyloid fibril formation of Aβ to 34.4 ± 6.8%. The antiamyloidal effects of HCAs were enhanced by esterification with alkyl alcohols, and the longer alkyl chain tended to be more effective except for SA. Aβ fibril formation was suppressed by the hexadecyl ester of CA, which was reduced to 8.8 ± 2.3%. In contrast, those of octyl and butyl esters were 19.3 ± 2.3% and 41.6 ± 6.1%, respectively. These results show that lipophilicity plays an important role in the antiamyloidal activities of esterified phenolic compounds.

  6. 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

    2015-11-01

    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.

  7. Scope and limitations of aliphatic Friedel-Crafts alkylations. Lewis acid catalyzed addition reactions of alkyl chlorides to carbon-carbon double bonds

    SciTech Connect

    Mayr, H.; Striepe, W.

    1983-04-22

    Lewis acid catalyzed addition reactions of alkyl halides with unsaturated hydrocarbons have been studied. 1:1 addition products are formed if the addends dissociate faster than the corresponding products; otherwise, polymerization takes place. For reaction conditions under which these compounds exist mainly undissociated, solvolysis constants of model compounds can be used to predict the outcome of any such addition reactions if systems with considerable steric hindrance are excluded.

  8. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  9. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  10. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  11. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  12. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  13. Acids and alkali resistant sticky superhydrophobic surfaces by one-pot electropolymerization of perfluoroalkyl alkyl pyrrole.

    PubMed

    Nicolas, Mael

    2010-03-15

    Over the past few years, electropolymerization of semifluorinated monomers like thiophene or pyrrole has been used as a gentle and effective method to generate, in one step, stable superhydrophobic surfaces. The synthetic route mostly involves the coupling reaction between a carboxylic acid and an alcohol, using a carboxy group-activated reagent and a catalyst. As a consequence, the electroformed surfaces present high liquid repellency due to the concomitant effect of roughness and low surface energy. Nevertheless, the ester connector can be cleaved under acidic and basic conditions, preventing its use under a range of environmental conditions. To overcome this drawback, a new perfluoroalkyl alkyl pyrrole has been synthesized, the fluorinated segment being connected to the electropolymerizable part via an alkyl chain, and electropolymerized, leading to surfaces that exhibit a static contact angle with water superior to 150 degrees and no sliding angle, over a wide pH range and with a long lifetime. This represents the first example of a pure conducting polymer surface with sticky superhydrophobicity not only in pure water but also in corrosive solutions such as acids and bases, giving rise to new prospects in practical applications. PMID:20060984

  14. Acids and alkali resistant sticky superhydrophobic surfaces by one-pot electropolymerization of perfluoroalkyl alkyl pyrrole.

    PubMed

    Nicolas, Mael

    2010-03-15

    Over the past few years, electropolymerization of semifluorinated monomers like thiophene or pyrrole has been used as a gentle and effective method to generate, in one step, stable superhydrophobic surfaces. The synthetic route mostly involves the coupling reaction between a carboxylic acid and an alcohol, using a carboxy group-activated reagent and a catalyst. As a consequence, the electroformed surfaces present high liquid repellency due to the concomitant effect of roughness and low surface energy. Nevertheless, the ester connector can be cleaved under acidic and basic conditions, preventing its use under a range of environmental conditions. To overcome this drawback, a new perfluoroalkyl alkyl pyrrole has been synthesized, the fluorinated segment being connected to the electropolymerizable part via an alkyl chain, and electropolymerized, leading to surfaces that exhibit a static contact angle with water superior to 150 degrees and no sliding angle, over a wide pH range and with a long lifetime. This represents the first example of a pure conducting polymer surface with sticky superhydrophobicity not only in pure water but also in corrosive solutions such as acids and bases, giving rise to new prospects in practical applications.

  15. Safety Assessment of Citric Acid, Inorganic Citrate Salts, and Alkyl Citrate Esters as Used in Cosmetics.

    PubMed

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

    2014-05-26

    The CIR Expert Panel (Panel) assessed the safety of citric acid, 12 inorganic citrate salts, and 20 alkyl citrate esters as used in cosmetics, concluding that these ingredients are safe in the present practices of use and concentration. Citric acid is reported to function as a pH adjuster, chelating agent, or fragrance ingredient. Some of the salts are also reported to function as chelating agents, and a number of the citrates are reported to function as skin-conditioning agents but other functions are also reported. The Panel reviewed available animal and clinical data, but because citric acid, calcium citrate, ferric citrate, manganese citrate, potassium citrate, sodium citrate, diammonium citrate, isopropyl citrate, stearyl citrate, and triethyl citrate are generally recognized as safe direct food additives, dermal exposure was the focus for these ingredients in this cosmetic ingredient safety assessment.

  16. The amphiphilic alkyl ester derivatives of l-ascorbic acid induce reorganization of phospholipid vesicles.

    PubMed

    Giudice, Francesca; Ambroggio, Ernesto E; Mottola, Milagro; Fanani, Maria Laura

    2016-09-01

    l-ascorbic acid alkyl esters (ASCn) are lipophilic forms of vitamin C, which maintain some of its antioxidant power. Those properties make this drug family attractive to be used in pharmacological preparations protecting other redox-sensible drugs or designed to reduce possible toxic oxidative processes. In this work, we tested the ability of l-ascorbic acid alkyl esters (ASCn) to modulate the structure, permeability, and rheological properties of phospholipid bilayers. The ASCn studied here (ASC16, ASC14, and ASC12) alter the structural integrity as well as the rheological properties of phospholipid membranes without showing any evident detergent activity. ASC14 appeared as the most efficient drug in destabilize the membrane structure of nano- and micro-size phospholipid liposomes inducing vesicle content leakage and shape elongation on giant unilamellar vesicles. It also was the most potent enhancer of membrane microviscosity and surface water structuring. Only ASC16 induced the formation of drug-enriched condensed domains after its incorporation into the lipid bilayer, while ASC12 appeared as the less membrane-disturbing compound, likely because of its poor, and more superficial, partition into the membrane. We also found that incorporation of ASCn into the lipid bilayers enhanced the reduction of membrane components, compared with soluble vitamin C. Our study shows that ASCn compounds, which vary in the length of the acyl chain, show different effects on phospholipid vesicles used as biomembrane models. Those variances may account for subtly differences in the effectiveness on their pharmacological applications. PMID:27342371

  17. Microbial biodegradation of aromatic alkanoic naphthenic acids is affected by the degree of alkyl side chain branching

    PubMed Central

    Johnson, Richard J; Smith, Ben E; Sutton, Paul A; McGenity, Terry J; Rowland, Steven J; Whitby, Corinne

    2011-01-01

    Naphthenic acids (NAs) occur naturally in oil sands and enter the environment through natural and anthropogenic processes. NAs comprise toxic carboxylic acids that are difficult to degrade. Information on NA biodegradation mechanisms is limited, and there are no studies on alkyl branched aromatic alkanoic acid biodegradation, despite their contribution to NA toxicity and recalcitrance. Increased alkyl side chain branching has been proposed to explain NA recalcitrance. Using soil enrichments, we examined the biodegradation of four aromatic alkanoic acid isomers that differed in alkyl side chain branching: (4′-n-butylphenyl)-4-butanoic acid (n-BPBA, least branched); (4′-iso-butylphenyl)-4-butanoic acid (iso-BPBA); (4′-sec-butylphenyl)-4-butanoic acid (sec-BPBA) and (4′-tert-butylphenyl)-4-butanoic acid (tert-BPBA, most branched). n-BPBA was completely metabolized within 49 days. Mass spectral analysis confirmed that the more branched isomers iso-, sec- and tert-BPBA were transformed to their butylphenylethanoic acid (BPEA) counterparts at 14 days. The BPEA metabolites were generally less toxic than BPBAs as determined by Microtox assay. n-BPEA was further transformed to a diacid, showing that carboxylation of the alkyl side chain occurred. In each case, biodegradation of the carboxyl side chain proceeded through beta-oxidation, which depended on the degree of alkyl side chain branching, and a BPBA degradation pathway is proposed. Comparison of 16S rRNA gene sequences at days 0 and 49 showed an increase and high abundance at day 49 of Pseudomonas (sec-BPBA), Burkholderia (n-, iso-, tert-BPBA) and Sphingomonas (n-, sec-BPBA). PMID:20962873

  18. Interaction of model aryl- and alkyl-boronic acids and 1,2-diols in aqueous solution.

    PubMed

    Marinaro, William A; Prankerd, Richard; Kinnari, Kaisa; Stella, Valentino J

    2015-04-01

    The goal of this work was to quantitate ester formation between alkyl and aryl boronic acids and vicinal-diols or 1,2-diols in aqueous solution. As used here, 1,2-diols includes polyols with one or more 1,2-diol pairs. Multiple techniques were used including apparent pKa shifts of the boronic acids using UV spectrophotometry (for aryl acids) and titration (for aryl and alkyl acids). Isothermal microcalorimetry was also used, with all reactions being enthalpically favored. For all the acids and 1,2-diols and the conditions studied, evidence only supported 1:1 ester formation. All the esters formed were found to be significantly more acidic, as Lewis acids, by 3-3.5 pKa units than the corresponding nonesterified boronic acid. The equilibrium constants for ester formation increased with increasing number of 1,2-diol pairs but stereochemistry may also play a role as sorbitol with five possible 1,2-diol pairs and five isomers (taking into account the stereochemistry of the alcohol groups) was twice as efficient at ester formation compared with mannitol, also with five possible 1,2-diol pairs but only three isomers. Alkyl boronic acids formed esters to a greater extent than aryl acids. Although some quantitative differences were seen between the various techniques used, rank ordering of the structure/reactivity was consistent. Formulation implications of ester formation between boronic acids and 1,2-diols are discussed. PMID:25600471

  19. Interaction of model aryl- and alkyl-boronic acids and 1,2-diols in aqueous solution.

    PubMed

    Marinaro, William A; Prankerd, Richard; Kinnari, Kaisa; Stella, Valentino J

    2015-04-01

    The goal of this work was to quantitate ester formation between alkyl and aryl boronic acids and vicinal-diols or 1,2-diols in aqueous solution. As used here, 1,2-diols includes polyols with one or more 1,2-diol pairs. Multiple techniques were used including apparent pKa shifts of the boronic acids using UV spectrophotometry (for aryl acids) and titration (for aryl and alkyl acids). Isothermal microcalorimetry was also used, with all reactions being enthalpically favored. For all the acids and 1,2-diols and the conditions studied, evidence only supported 1:1 ester formation. All the esters formed were found to be significantly more acidic, as Lewis acids, by 3-3.5 pKa units than the corresponding nonesterified boronic acid. The equilibrium constants for ester formation increased with increasing number of 1,2-diol pairs but stereochemistry may also play a role as sorbitol with five possible 1,2-diol pairs and five isomers (taking into account the stereochemistry of the alcohol groups) was twice as efficient at ester formation compared with mannitol, also with five possible 1,2-diol pairs but only three isomers. Alkyl boronic acids formed esters to a greater extent than aryl acids. Although some quantitative differences were seen between the various techniques used, rank ordering of the structure/reactivity was consistent. Formulation implications of ester formation between boronic acids and 1,2-diols are discussed.

  20. Alkyl hydroperoxide reductase enhances the growth of Leuconostoc mesenteroides lactic acid bacteria at low temperatures.

    PubMed

    Goto, Seitaro; Kawamoto, Jun; Sato, Satoshi B; Iki, Takashi; Watanabe, Itaru; Kudo, Kazuyuki; Esaki, Nobuyoshi; Kurihara, Tatsuo

    2015-01-01

    Lactic acid bacteria (LAB) can cause deterioration of food quality even at low temperatures. In this study, we investigated the cold-adaptation mechanism of a novel food spoilage LAB, Leuconostoc mesenteroides NH04 (NH04). L. mesenteroides was isolated from several spoiled cooked meat products at a high frequency in our factories. NH04 grew rapidly at low temperatures within the shelf-life period and resulted in heavy financial losses. NH04 grew more rapidly than related strains such as Leuconostoc mesenteroides NBRC3832 (NBRC3832) at 10°C. Proteome analysis of NH04 demonstrated that this strain produces a homolog of alkyl hydroperoxide reductase--AhpC--the expression of which can be induced at low temperatures. The expression level of AhpC in NH04 was approximately 6-fold higher than that in NBRC3832, which was grown under the same conditions. Although AhpC is known to have an anti-oxidative role in various bacteria by catalyzing the reduction of alkyl hydroperoxide and hydrogen peroxide, the involvement of AhpC in cold adaptation of food spoilage bacteria was unclear. We introduced an expression plasmid containing ahpC into NBRC3832, which grows slower than NH04 at 10°C, and found that expression of AhpC enhanced growth. These results demonstrated that AhpC, which likely increases anti-oxidative capacity of LAB, plays an important role in their rapid growth at low temperatures.

  1. δ-Aminolevulinic acid dehydrase activity in the blood of men working with lead alkyls

    PubMed Central

    Millar, J. A.; Thompson, G. G.; Goldberg, A.; Barry, P. S. I.; Lowe, E. H.

    1972-01-01

    Millar, J. A., Thompson, G. G., Goldberg, A., Barry, P. S. I., and Lowe, E. H. (1972).Brit. J. industr. Med.,29, 317-320. δ-Aminolevulinic acid dehydrase activity in the blood of men working with lead alkyls. The activity of erythrocyte ALA1-dehydrase is inhibited in vivo at blood lead (Pb2+) levels within the upper range of normal (20-40 μg/100 ml) and in vitro at lead concentrations greater than 10-7 M. In view of the high sensitivity of the enzyme to Pb2+, the levels of enzyme activity in the blood of men occupationally exposed to lead alkyls, particularly tetraethyllead, were measured. It was found that the enzyme activity in an exposed group of men was significantly less (P<0·001) than in a control group, the respective mean values being 220 and 677 units of enzyme activity. Tetraethyllead is metabolized in the body via triethyllead and diethyllead ions. As the latter compound possesses properties similar to Pb2+, it was synthesized in the laboratory and its effect on ALA-dehydrase was studied. Diethyllead ion was found to inhibit ALA-dehydrase activity at concentrations greater than 5 x 10-5 M, although the degree of inhibition was less than that obtained with Pb2+. These results suggest that exposure to tetraethyllead can cause a decrease in erythrocyte ALA-dehydrase activity. PMID:5044603

  2. Hydrophilic interaction liquid chromatography-tandem mass spectrometry methylphosponic and alkyl methylphosphonic acids determination in environmental samples after pre-column derivatization with p-bromophenacyl bromide.

    PubMed

    Baygildiev, T M; Rodin, I A; Stavrianidi, A N; Braun, A V; Lebedev, A T; Rybalchenko, I V; Shpigun, O A

    2016-04-15

    Once exposed to the environment organophosphate nerve agents readily degrade by rapid hydrolysis to the corresponding alkyl methylphosphonic acids which do not exist in nature. These alkyl methylphosphonic acids are finally slowly hydrolyzed to methylphosphonic acid. Methylphosphonic acid is the most stable hydrolysis product of organophosphate nerve agents, persisting in environment for a long time. A highly sensitive method of methylphosphonic acid and alkyl methylphosphonic acids detection in dust and ground mixed samples has been developed and validated. The fact that alkyl methylphosphonic acids unlike methylphosphonic acid did not react with p-bromophenacyl bromide under chosen conditions was discovered. This allowed simultaneous chromatographic separation and mass spectrometric detection of derivatized methylphosphonic acid and underivatized alkyl methylphosphonic acids using HILIC-MS/MS method. Very simple sample pretreatment with high recoveries for each analyte was developed. Methylphosphonic acid pre-column derivate and alkyl methylphosphonic acids were detected using tandem mass spectrometry with electrospray ionization after hydrophilic interaction liquid chromatography separation. The developed approach allows achieving ultra-low detection limits: 200 pg mL(-1) for methylphosphonic acid, 70 pg mL(-1) for ethyl methylphosphonic acid, 8 pg mL(-1) for i-propyl methylphosphonic acid, 8 pg mL(-1) for i-butyl methylphosphonic acid, 5 pg mL(-1) for pinacolyl methylphosphonic acid in the extracts of dust and ground mixed samples. This approach was successfully applied to the dust and ground mixed samples from decommissioned plant for the production of chemical weapons.

  3. Hydrophilic interaction liquid chromatography-tandem mass spectrometry methylphosponic and alkyl methylphosphonic acids determination in environmental samples after pre-column derivatization with p-bromophenacyl bromide.

    PubMed

    Baygildiev, T M; Rodin, I A; Stavrianidi, A N; Braun, A V; Lebedev, A T; Rybalchenko, I V; Shpigun, O A

    2016-04-15

    Once exposed to the environment organophosphate nerve agents readily degrade by rapid hydrolysis to the corresponding alkyl methylphosphonic acids which do not exist in nature. These alkyl methylphosphonic acids are finally slowly hydrolyzed to methylphosphonic acid. Methylphosphonic acid is the most stable hydrolysis product of organophosphate nerve agents, persisting in environment for a long time. A highly sensitive method of methylphosphonic acid and alkyl methylphosphonic acids detection in dust and ground mixed samples has been developed and validated. The fact that alkyl methylphosphonic acids unlike methylphosphonic acid did not react with p-bromophenacyl bromide under chosen conditions was discovered. This allowed simultaneous chromatographic separation and mass spectrometric detection of derivatized methylphosphonic acid and underivatized alkyl methylphosphonic acids using HILIC-MS/MS method. Very simple sample pretreatment with high recoveries for each analyte was developed. Methylphosphonic acid pre-column derivate and alkyl methylphosphonic acids were detected using tandem mass spectrometry with electrospray ionization after hydrophilic interaction liquid chromatography separation. The developed approach allows achieving ultra-low detection limits: 200 pg mL(-1) for methylphosphonic acid, 70 pg mL(-1) for ethyl methylphosphonic acid, 8 pg mL(-1) for i-propyl methylphosphonic acid, 8 pg mL(-1) for i-butyl methylphosphonic acid, 5 pg mL(-1) for pinacolyl methylphosphonic acid in the extracts of dust and ground mixed samples. This approach was successfully applied to the dust and ground mixed samples from decommissioned plant for the production of chemical weapons. PMID:26965649

  4. Uptake of perfluorinated alkyl acids by hydroponically grown lettuce (Lactuca sativa).

    PubMed

    Felizeter, Sebastian; McLachlan, Michael S; de Voogt, Pim

    2012-11-01

    An uptake study was carried out to assess the potential human exposure to perfluorinated alkyl acids (PFAAs) through the ingestion of vegetables. Lettuce (Lactuca sativa) was grown in PFAA-spiked nutrient solutions at four different concentrations, ranging from 10 ng/L to 10 μg/L. Eleven perfluorinated carboxylic acids (PFCAs) and three perfluorinated sulfonic acids (PFSAs) were analyzed by HPLC-MS/MS. At the end of the experiment, the major part of the total mass of each of the PFAAs (except the short-chain, C4-C7, PFCAs) taken up by plants appeared to be retained in the nonedible part, viz. the roots. Root concentration factors (RCF), foliage/root concentration factors (FRCF), and transpiration stream concentration factors (TSCF) were calculated. For the long chained PFAAs, RCF values were highest, whereas FRCF were lowest. This indicates that uptake by roots is likely governed by sorption of PFAAs to lipid-rich root solids. Translocation from roots to shoots is restricted and highly depending on the hydrophobicity of the compounds. Although the TSCF show that longer-chain PFCAs (e.g., perfluorododecanoic acid) get better transferred from the nutrient solution to the foliage than shorter-chain PFCAs (e.g., perfluoroheptanoic acid), the major fraction of longer-chain PFCAs is found in roots due to additional adsorption from the spiked solution. Due to the strong electron-withdrawing effect of the fluorine atoms the role of the negative charge of the dissociated PFAAs is likely insignificant.

  5. Polyol-acid anhydride-n-alkyl-alkylene diamine reaction product and motor fuel composition containing same

    SciTech Connect

    Sung, R.L.; Jenkins, R.H. Jr.

    1987-02-17

    A fuel composition for an internal combustion engine comprising: (a) a major portion of a liquid hydrocarbon fuel and (b) a minor amount, as a deposit inhibitor additive, of a reaction product of a process comprising: (i) reacting a dibasic acid anhydride with a polyol, thereby forming an ester of maleic acid; (ii) reacting the ester of maleic acid with an N-alkyl-alkylene diamine, thereby forming the reaction product; and (iii) recovering the reaction product.

  6. Transition metal ion-assisted photochemical generation of alkyl halides and hydrocarbons from carboxylic acids

    SciTech Connect

    Carraher, Jack; Pestovsky, Oleg; Bakac, Andreja

    2012-03-14

    Near-UV photolysis of aqueous solutions of propionic acid and aqueous Fe3+ in the absence of oxygen generates a mixture of hydrocarbons (ethane, ethylene and butane), carbon dioxide, and Fe2+. The reaction becomes mildly catalytic (about five turnovers) in the presence of oxygen which converts a portion of alkyl radicals to oxidizing intermediates that reoxidize Fe2+. The photochemistry in the presence of halide ions (X− = Cl−, Br−) generates ethyl halides via halogen atom abstraction from FeXn3−n by ethyl radicals. Near-quantitative yields of C2H5X are obtained at ≥0.05 M X−. Competition experiments with Co(NH3)5Br2+ provided kinetic data for the reaction of ethyl radicals with FeCl2+ (k = (4.0 ± 0.5) × 106 M−1 s−1) and with FeBr2+ (k = (3.0 ± 0.5) × 107 M−1 s−1). Photochemical decarboxylation of propionic acid in the presence of Cu2+ generates ethylene and Cu+. Longer-chain acids also yield alpha olefins as exclusive products. These reactions become catalytic under constant purge with oxygen which plays a dual role. It reoxidizes Cu+ to Cu2+, and removes gaseous olefins to prevent accumulation of Cu+(olefin) complexes and depletion of Cu2+. The results underscore the profound effect that the choice of metal ions, the medium, and reaction conditions exert on the photochemistry of carboxylic acids.

  7. Peroxide promoted tunable decarboxylative alkylation of cinnamic acids to form alkenes or ketones under metal-free conditions.

    PubMed

    Ji, Jing; Liu, Ping; Sun, Peipei

    2015-05-01

    A tunable decarboxylative alkylation of cinnamic acids with alkanes was developed to form alkenes or ketones under transition metal-free conditions. In the presence of DTBP or DTBP/TBHP, the reaction gave alkenes and ketones respectively via a radical mechanism in moderate to good yields.

  8. CHEMISTRY OF FOG WATER IN CALIFORNIA'S CENTRAL VALLEY: 2. PHOTOCHEMICAL TRANSFORMATIONS OF AMINO ACIDS AND ALKYL AMINES. (R825433)

    EPA Science Inventory

    Although amino compounds are seemingly ubiquitous in atmospheric particles and deposition, little is known of their fate in the troposphere. We report here on the fate of 21 amino acids and alkyl amines in fog waters from Davis, California, illuminated with simulated sunlight ...

  9. Oxidative photodegradation of herbicide fenuron in aqueous solution by natural iron oxide α-Fe2O3, influence of polycarboxylic acids.

    PubMed

    Kribéche, Mohamed El Amine; Mechakra, Hind; Sehili, Tahar; Brosillon, Stephan

    2016-01-01

    The photodegradation of the herbicide fenuron (1,1-dimethyl-3-phenylurea) by using a natural iron oxide (NIO), α-Fe2O3, in aqueous solution at acidic pH has been undertaken. The NIO was characterized by the Raman spectroscopy method. The degradation pathways and the formation of degradation products were studied. A high-pressure mercury lamp and sunlight were employed as light source. Fenuron photodegradation using NIO with oxalic acid followed the pseudo-first-order kinetics, the optimal experimental conditions were [oxalic acid]0 = 10(-3) M and [NIO] = 0.1 g L(-1) at pH 3. A UVA/NIO/oxalic acid system led to a low fenuron half-life (60 min). The results were even better when solar light is used (30 min). The variables studied were the doses of iron oxide, of carboxylic acids, the solution pH and the effect of sunlight irradiation. The effects of four carboxylic acids, oxalic, citric, tartaric and malic acids, on the fenuron photodegradation with NIO have been investigated, oxalic acid was the most effective carboxylic acid used at pH 3. A similar trend was observed for the removal of total organic carbon (TOC), 75% of TOC was removed. The analytical study showed many aromatic intermediates, short-chain carboxylic acids and inorganic ion. PMID:26102217

  10. Formation of self-assembled monolayers with homogeneously mixed, loosely packed alkyl groups using unsymmetrical dialkyldithiophosphinic acids.

    PubMed

    San Juan, Ronan R; Carmichael, Tricia Breen

    2012-12-21

    We report the formation and characterization of self-assembled monolayers (SAMs) formed from unsymmetrical dialkyldithiophosphinic acid (R(1)R(2)DTPA) adsorbates [CH(3)(CH(2))(n)][CH(3)(CH(2))(15)]P(S)SH (n = 5, 9) on gold substrates. These SAMs were characterized using X-ray photoelectron spectroscopy, reflection-absorption infrared spectroscopy, contact angle goniometry, electrochemical impedance spectroscopy, and atomic force microscopy. Unsymmetrical R(1)R(2)DTPA SAMs contain mixtures of bidentate and monodentate adsorbates, similar to SAMs formed from analogous symmetrical R(2)DTPAs. In unsymmetrical R(1)R(2)DTPA SAMs, however, the short alkyl substituent of the R(1)R(2)DTPA adsorbates enforces spacing between the long hexadecyl substituents, which disrupts van der Waals interactions and causes the hexadecyl groups to be loosely packed and disordered. The structure of the SAM depends on the length of the short alkyl substituent: The hexyl chains in the C(6)C(16)DTPA SAM are not long enough to stabilize the alkyl zone close to the substrate, leading to highly disordered SAMs with a low molecular packing density in which the hexadecyl chains lie down to fill the gaps between adjacent adsorbates. In contrast, the additional van der Waals interactions provided by the decyl chains of the C(10)C(16)DTPA SAM enable dense molecular packing in the alkyl zone close to the substrate. The structure of the SAM consists of a zone close to the substrate composed of a packed alkyl layer, with hexadecyl chains protruding above to form a loosely packed, disordered alkyl layer. Regardless of the structural differences between the C(6)C(16)DTPA and C(10)C(16)DTPA SAMs, both SAMs exhibit homogeneous mixing of the alkyl chains within the SAM, demonstrating that binding two different chains to a single headgroup is an effective method to prevent phase segregation.

  11. DDQ-promoted dehydrogenation from natural rigid polycyclic acids or flexible alkyl acids to generate lactones by a radical ion mechanism.

    PubMed

    Ding, Ye; Huang, Zhangjian; Yin, Jian; Lai, Yisheng; Zhang, Shibo; Zhang, Zhiguo; Fang, Lei; Peng, Sixun; Zhang, Yihua

    2011-09-01

    A novel and facile DDQ-mediated dehydrogenation from natural rigid polycyclic acids or flexible alkyl acids to generate lactones is described. The formation of lactones proceeds by a radical ion mechanism, which has been established by DPPH˙-mediated chemical identification, ESR spectroscopy and an enol intermediate trapping. PMID:21766102

  12. Polycarboxylic acids as network modifiers for water durability improvement of inorganic-organic hybrid tin-silico-phosphate low-melting glasses

    SciTech Connect

    Menaa, Bouzid . E-mail: bouzidmenaa@noncry.kuicr.kyoto-u.ac.jp; Mizuno, Megumi; Takahashi, Masahide . E-mail: masahide@noncry.kuicr.kyoto-u.ac.jp; Tokuda, Yomei; Yoko, Toshinobu

    2006-02-15

    We investigated the water durability of the inorganic-organic hybrid tin-silico-phosphate glasses Me{sub 2}SiO-SnO-P{sub 2}O{sub 5} (Me designs the organic methyl group) doped with organic acids (salicylic acid (SA), tartaric acid (TA), citric acid (Canada) and butane tetracarboxylic acid (BTCA)) containing one or more of carboxylic groups per molecule. The structure, thermal properties and durability of the final glasses obtained via a non-aqueous acid-base reaction were discussed owing to the nature and the concentration of the acid added. {sup 29}Si magic angle spinning (MAS) NMR and {sup 31}P MAS NMR spectra, respectively, showed clearly a modification of the network in the host glass matrix of the Me{sub 2}SiO-SnO-P{sub 2}O{sub 5} system. The polycondensation enhancement to form -P-O-Si-O-P- linkages (PSP) and the increase of the Q {sup 2} unit (two bridging oxygens per phosphorus atom) over the Q {sup 3} unit (three bridging oxygens per phosphorus atom) as a function of the acid in the order SAacids containing a large number of carboxylic groups per molecule. The presence of carboxylic groups of the acid acting as network modifier may retard the movement of water molecules through the glasses due to the steric hindrance strengthening the PSP connections in a chain-like structure.

  13. Mass Balance of Perfluorinated Alkyl Acids in a Pristine Boreal Catchment.

    PubMed

    Filipovic, Marko; Laudon, Hjalmar; McLachlan, Michael S; Berger, Urs

    2015-10-20

    Mass balances of ten individual perfluorinated alkyl acids (PFAAs) in two nested pristine catchments in Northern Sweden with different sizes and hydrological functions were assembled for 2011-2012. Concentrations of PFAAs in rain and snowmelt, as well as in streamwater at the outlet of the two watersheds were measured and used to calculate PFAA atmospheric inputs to and riverine outputs from the catchments. The results generally showed a great excess of PFAA inputs for both catchments over the whole study year. However, during the spring flood period, the inputs and outputs were within a factor of 2 for several PFAAs and the streamwater showed PFAA patterns resembling the patterns in rain (as opposed to snowmelt), suggesting that snowmelt water infiltrating the ground had displaced water from the previous summer. Comparison of PFAA mass balances between the two catchments further suggested that atmospheric inputs of short-chain (replacement) perfluoroalkyl carboxylic acids had increased in the years before sampling, while inputs of the legacy perfluorooctane sulfonic acid had decreased. Overall, the mass balances indicate that a considerable portion of the PFAAs deposited from the atmosphere are stored in soil and may be released to surface and marine water environments in the future.

  14. Mass Balance of Perfluorinated Alkyl Acids in a Pristine Boreal Catchment.

    PubMed

    Filipovic, Marko; Laudon, Hjalmar; McLachlan, Michael S; Berger, Urs

    2015-10-20

    Mass balances of ten individual perfluorinated alkyl acids (PFAAs) in two nested pristine catchments in Northern Sweden with different sizes and hydrological functions were assembled for 2011-2012. Concentrations of PFAAs in rain and snowmelt, as well as in streamwater at the outlet of the two watersheds were measured and used to calculate PFAA atmospheric inputs to and riverine outputs from the catchments. The results generally showed a great excess of PFAA inputs for both catchments over the whole study year. However, during the spring flood period, the inputs and outputs were within a factor of 2 for several PFAAs and the streamwater showed PFAA patterns resembling the patterns in rain (as opposed to snowmelt), suggesting that snowmelt water infiltrating the ground had displaced water from the previous summer. Comparison of PFAA mass balances between the two catchments further suggested that atmospheric inputs of short-chain (replacement) perfluoroalkyl carboxylic acids had increased in the years before sampling, while inputs of the legacy perfluorooctane sulfonic acid had decreased. Overall, the mass balances indicate that a considerable portion of the PFAAs deposited from the atmosphere are stored in soil and may be released to surface and marine water environments in the future. PMID:26390224

  15. Alkylation of nucleic acids by DNA-targeted 4-anilinoquinolinium aniline mustards: kinetic studies.

    PubMed

    O'Connor, C J; Denny, W A; Fan, J Y

    1991-01-01

    The rate of constant for hydrolysis of a series of 4-substituted aniline mustards Ar-X-pC6H4-N(CH2CH2Cl)2, where Ar is 4-anilinoquinolinium and X = O, CH2, CONH and CO, have been measured in water and 0.02 M imidazole buffer at 37 degrees C and in 50% aqueous acetone at 66 degrees C. The equilibrium binding constants of the compounds and their hydrolysis products to nucleic acids of differing base composition have been determined at varying ionic strengths, and the results are consistent with the compounds binding as expected in the DNA minor groove. The alkylating reactivity of the mustards towards these nucleic acids has been measured in water at 37 degrees C and in 0.01 M HEPES buffer over a range of temperatures from 25 degrees C to 60 degrees C. Evaluation of the thermodynamic parameters for these kinetic and equilibrium studies suggests that the interaction with nucleic acids is via an internal SN2 mechanism involving an aziridinium ion.

  16. Uptake of perfluorinated alkyl acids by hydroponically grown lettuce (Lactuca sativa).

    PubMed

    Felizeter, Sebastian; McLachlan, Michael S; de Voogt, Pim

    2012-11-01

    An uptake study was carried out to assess the potential human exposure to perfluorinated alkyl acids (PFAAs) through the ingestion of vegetables. Lettuce (Lactuca sativa) was grown in PFAA-spiked nutrient solutions at four different concentrations, ranging from 10 ng/L to 10 μg/L. Eleven perfluorinated carboxylic acids (PFCAs) and three perfluorinated sulfonic acids (PFSAs) were analyzed by HPLC-MS/MS. At the end of the experiment, the major part of the total mass of each of the PFAAs (except the short-chain, C4-C7, PFCAs) taken up by plants appeared to be retained in the nonedible part, viz. the roots. Root concentration factors (RCF), foliage/root concentration factors (FRCF), and transpiration stream concentration factors (TSCF) were calculated. For the long chained PFAAs, RCF values were highest, whereas FRCF were lowest. This indicates that uptake by roots is likely governed by sorption of PFAAs to lipid-rich root solids. Translocation from roots to shoots is restricted and highly depending on the hydrophobicity of the compounds. Although the TSCF show that longer-chain PFCAs (e.g., perfluorododecanoic acid) get better transferred from the nutrient solution to the foliage than shorter-chain PFCAs (e.g., perfluoroheptanoic acid), the major fraction of longer-chain PFCAs is found in roots due to additional adsorption from the spiked solution. Due to the strong electron-withdrawing effect of the fluorine atoms the role of the negative charge of the dissociated PFAAs is likely insignificant. PMID:23043263

  17. α(δ')-Michael addition of alkyl amines to dimethyl (E)-hex-2-en-4-ynedioate: synthesis of α,β-dehydroamino acid derivatives.

    PubMed

    Chavan, Arjun S; Deng, Jie-Cheng; Chuang, Shih-Ching

    2013-02-27

    The direct nucleophilic addition of alkyl amines to the α(δ')-carbon atom of dimethyl (E)-hex-2-en-4-ynedioate to generate α,β-dehydroamino acid derivatives is reported. Herein, we have studied the reactivity of various primary and secondary alkyl amines in the α-selective nucleophilic conjugate addition to conjugated dimethyl (E)-hex-2-en-4-ynedioate. The reaction with primary alkyl amines gives only the (2E,4E)-stereoisomer, while that with secondary alkyl amines gives the (2E,4E) and (2Z,4E)-stereoisomers of dimethyl (2-alkylamino)-muconic ester.

  18. Thermal stability and ordering study of long- and short-alkyl chain phosphonic acid multilayers.

    PubMed

    de Pauli, Muriel; Prado, Mariana de Castro; Matos, Matheus Josue Souza; Fontes, Giselle Nogueira; Perez, Carlos Alberto; Mazzoni, Mario Sergio Carvalho; Neves, Bernardo Ruegger Almeida; Malachias, Angelo

    2012-10-30

    Long-range order evolution of self-assembled phosphonic acid multilayers as a function of temperature is studied here for two molecules with different alkyl chain length. By using synchrotron conventional diffraction, distinct order configurations are retrieved on phosphonic acid multilayers and their thermodynamic behavior monitored by energy-dispersive diffraction. This later technique allows us to observe the system behavior near order-disorder temperatures, as well as to determine the most stable configurations in the range from room temperature up to 120 °C. Planar order is also addressed by wide-angle X-ray scattering (WAXS) transmission experiments. Order parameter phase diagrams are built based on the experimental results, showing the dominant configuration at each temperature. The multilayer molecular long-range order retrieved from the experiments is corroborated by first principles calculations based on the Density Functional Theory. The bulk configurations depicted in this work are produced by molecule-molecule interactions and allow for future comparisons with the behavior of ordered molecules in few-monolayers configurations, commonly used in organic devices, where the presence of surfaces and interfaces strongly affects the molecule packing.

  19. 40 CFR 721.10441 - 1,2-Benzenedicarboxylic acid, di-C7-14-branched and linear alkyl esters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters. 721.10441 Section 721.10441 Protection of Environment ENVIRONMENTAL...-branched and linear alkyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, di-C7-14-branched and linear...

  20. 40 CFR 721.10442 - 1,2-Benzenedicarboxylic acid, di-C6-14-branched and linear alkyl esters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters. 721.10442 Section 721.10442 Protection of Environment ENVIRONMENTAL...-branched and linear alkyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, di-C6-14-branched and linear...

  1. Surface active molecules: preparation and properties of long chain n-acyl-l-alpha-amino-omega-guanidine alkyl acid derivatives.

    PubMed

    Infante, R; Dominguez, J G; Erra, P; Julia, R; Prats, M

    1984-12-01

    Synopsis A new route for the synthesis of long chain N(alpha)-acyl-l-alpha-amino-omega-guamdine alkyl acid derivatives, with cationic or amphoteric character has been established. The general formula of these compounds is shown below. A physico-chemical and antimicrobial study of these products as a function of the alkyl ester or sodium salt (R), the straight chain length of the fatty acid residue (x) and the number of carbons between the omega-guanidine and omega-carboxyl group (n) has been investigated. The water solubility, surface tension, critical micelle concentration (c.m.c.) and minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria (including Pseudomonas) has been determined. Dicyclohexylcarbodiimide has been used to condense fatty acids and alpha-amino-omega-guanidine alkyl acids. In these conditions protection of the omega-guanidine group is not necessary. The main characteristic of this synthetic procedure is the use of very mild experimental conditions (temperature, pH) to form the amide linkage which leads to pure optical compounds in high yield in the absence of electrolytes. The results show that some structural modifications, particularly the protection of the carboxyl group, promote variations of the surfactant and antimicrobial properties. Only those molecules with the blocked carboxyl group (cationic molecules, where R = Me, Et or Pr) showed a good surfactant and antimicrobial activity. When the carboxyl group was unprotected (amphoteric molecules, where R = Na(+)) the resulting compounds were inactive.

  2. Perfluorinated alkylated acids in groundwater and drinking water: identification, origin and mobility.

    PubMed

    Eschauzier, Christian; Raat, Klaasjan J; Stuyfzand, Pieter J; De Voogt, Pim

    2013-08-01

    Human exposure to perfluorinated alkylated acids (PFAA) occurs primarily via the dietary intake and drinking water can contribute significantly to the overall PFAA intake. Drinking water is produced from surface water and groundwater. Waste water treatment plants have been identified as the main source for PFAA in surface waters and corresponding drinking water. However, even though groundwater is an important source for drinking water production, PFAA sources remain largely uncertain. In this paper, we identified different direct and indirect sources of PFAA to groundwater within the catchment area of a public supply well field (PSWF) in The Netherlands. Direct sources were landfill leachate and water draining from a nearby military base/urban area. Indirect sources were infiltrated rainwater. Maximum concentrations encountered in groundwater within the landfill leachate plume were 1.8 μg/L of non branched perfluorooctanoic acid (L-PFOA) and 1.2 μg/L of perfluorobutanoic acid (PFBA). Sum concentrations amounted to 4.4 μg/L total PFAA. The maximum concentration of ΣPFAA in the groundwater originating from the military camp was around 17 ng/L. Maximum concentrations measured in the groundwater halfway the landfill and the PWSF (15 years travel distance) were 29 and 160 ng/L for L-PFOA and PFBA, respectively. Concentrations in the groundwater pumping wells (travel distance >25 years) were much lower: 0.96 and 3.5 ng/L for L-PFOA and PFBA, respectively. The chemical signature of these pumping wells corresponded to the signature encountered in other wells sampled which were fed by water that had not been in contact with potential contaminant sources, suggesting a widespread diffuse contamination from atmospheric deposition.

  3. Root uptake and translocation of perfluorinated alkyl acids by three hydroponically grown crops.

    PubMed

    Felizeter, Sebastian; McLachlan, Michael S; De Voogt, Pim

    2014-04-16

    Tomato, cabbage, and zucchini plants were grown hydroponically in a greenhouse. They were exposed to 14 perfluorinated alkyl acids (PFAAs) at four different concentrations via the nutrient solution. At maturity the plants were harvested, and the roots, stems, leaves, twigs (where applicable), and edible parts (tomatoes, cabbage head, zucchinis) were analyzed separately. Uptake and transfer factors were calculated for all plant parts to assess PFAA translocation and distribution within the plants. Root concentration factors were highest for long-chain PFAAs (>C11) in all three plant species, but these chemicals were not found in the edible parts. All other PFAAs were present in all above-ground plant parts, with transpiration stream concentration factors (TSCFs) of 0.05-0.25. These PFAAs are taken up with the transpiration stream and accumulate primarily in the leaves. Although some systematic differences were observed, overall their uptake from nutrient solution to roots and their further distribution within the plants were similar between plant species and among PFAAs.

  4. Root uptake and translocation of perfluorinated alkyl acids by three hydroponically grown crops.

    PubMed

    Felizeter, Sebastian; McLachlan, Michael S; De Voogt, Pim

    2014-04-16

    Tomato, cabbage, and zucchini plants were grown hydroponically in a greenhouse. They were exposed to 14 perfluorinated alkyl acids (PFAAs) at four different concentrations via the nutrient solution. At maturity the plants were harvested, and the roots, stems, leaves, twigs (where applicable), and edible parts (tomatoes, cabbage head, zucchinis) were analyzed separately. Uptake and transfer factors were calculated for all plant parts to assess PFAA translocation and distribution within the plants. Root concentration factors were highest for long-chain PFAAs (>C11) in all three plant species, but these chemicals were not found in the edible parts. All other PFAAs were present in all above-ground plant parts, with transpiration stream concentration factors (TSCFs) of 0.05-0.25. These PFAAs are taken up with the transpiration stream and accumulate primarily in the leaves. Although some systematic differences were observed, overall their uptake from nutrient solution to roots and their further distribution within the plants were similar between plant species and among PFAAs. PMID:24646206

  5. Influence of alkyl chain length on calcium phosphate deposition onto titanium surfaces modified with alkylphosphonic acid monolayers.

    PubMed

    Wu, Jiang; Hirata, Isao; Zhao, Xianghui; Gao, Bo; Okazaki, Masayuki; Kato, Koichi

    2013-08-01

    Much attention has been paid to the modification of a titanium surface with an alkylphosphonic acid (PA)-based self-assembled monolayer (SAM) to accelerate hydroxyapatite (HA) deposition on the surface. In order to further accelerate the rate of HA deposition, we examined here the effect of alkyl chain length of SAMs on the formation of a HA layer. PAs with three different alkyl chain lengths (3, 6, and 16 methylene units) were used for the preparation of a SAM on titanium. The titanium specimens with monolayers were soaked in a simulated body fluid under physiological conditions for 4 weeks. The deposited substances were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. These analyses revealed that the formation of PA SAMs accelerate the deposition of poorly crystallized HA, in an alkyl chain length-dependent manner. Among PAs studied here, PA containing a 16-carbon alkyl chain gave rise to the titanium surface most effective for the deposition of HA.

  6. 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.

  7. Inhibition of barium sulfate deposition by polycarboxylates of various molecular structures

    SciTech Connect

    van der Leeden, M.C.; van Rosmalen, G.M. )

    1990-02-01

    To establish a relationship between the molecular structure of polycarboxylates and their growth-retarding influence on barium sulfate, seeded-suspension-growth experiments were performed at various inhibitor concentrations and pH values. Two types of polycarboxylates with a molecular structure based on their polyacrylic or maleic acid were studied. The molecular structure of these compounds were varied by particle substitution with monomers containing hydroxyl, amide, and sulfonic acid, as well as hydrophobic groups. Hydrophobic groups are detrimental to good inhibitor performance, whereas the introduction of OH, NH {sub 2}, or SO {sub 3} H groups presents opportunities to enhance the inhibitor effectiveness. The sequence in performance of the compounds on barium sulfate was compared with the sequence formerly obtained for calcium sulfate dihydrate.

  8. Applications of FT-IR spectroscopy to the studies of esterification and crosslinking of cellulose by polycarboxylic acids: Part II. The performance of the crosslinked cotton fabrics

    NASA Astrophysics Data System (ADS)

    Wei, Weishu; Yang, Charles Q.

    1998-06-01

    Durable press finishing processes are commonly used in the textile industry to produce wrinkle-free cotton fabrics and garments. A durable press finishing agent forms covalent bands with cellulosic hydroxyl groups, thus crosslinking the cellulose molecules. The crosslinking of cellulose increases wrinkle resistance of the treated cotton fabric and reduces fabric mechanical strength. Wrinkle recovery angle (WRA) and tensile strength are the two most important parameters used to evaluate the performance of the crosslinked cotton fabrics and garments. In this study, we investigated the correlation between WRA and tensile strength on one hand, and the amount of crosslinkages formed by the crosslinking agents including dimethyloldihydroxylethyleneurea (DMDHEU) and 1,2,3,4-butanetetracarboxylic acid (BTCA) determined by FT-IR spectroscopy on the other hand. Linear regression curves between the carbonyl band absorbance, and WRA and tensile strength of the treated cotton fabric were developed. The data indicated that FT-IR spectroscopy is a reliable technique for predicting the performance of durable press finished cotton fabrics, therefore can be used as a convenient instrumental method for quality control in the textile and garment industry.

  9. Perfluorinated alkyl acids in the plasma of South African crocodiles (Crocodylus niloticus).

    PubMed

    Christie, Ian; Reiner, Jessica L; Bowden, John A; Botha, Hannes; Cantu, Theresa M; Govender, Danny; Guillette, Matthew P; Lowers, Russell H; Luus-Powell, Wilmien J; Pienaar, Danie; Smit, Willem J; Guillette, Louis J

    2016-07-01

    Perfluorinated alkyl acids (PFAAs) are environmental contaminants that have been used in many products for over 50 years. Interest and concern has grown since 2000 on the widespread presence of PFAAs, when it was discovered that PFAAs were present in wildlife samples around the northern hemisphere. Since then, several studies have reported PFAAs in wildlife from many locations, including the remote regions of Antarctica and the Arctic. Although there are a multitude of studies, few have reported PFAA concentrations in reptiles and wildlife in the Southern Hemisphere. This study investigated the presence of PFAAs in the plasma of Nile crocodiles (Crocodylus niloticus) from South Africa. Crocodiles were captured from five sites in and around the Kruger National Park, South Africa, and plasma samples examined for PFAAs. Perfluorooctane sulfonate (PFOS) was the most frequent PFAA detected; with median values of 13.5 ng/g wet mass in crocodiles. In addition to PFOS, long chain perfluorinated carboxylic acids were also detected. Correlations between total length and PFAA load were investigated, as were differences in PFAA accumulation between sexes. No correlations were seen between crocodile size, nor were there sex-related differences. Spatial differences were examined and significant differences were observed in samples collected from the different sites (p < 0.05). Flag Boshielo Dam had the highest PFOS measurements, with a median concentration of 50.3 ng/g wet mass, when compared to the other sites (median concentrations at other sites below 14.0 ng/g wet mass). This suggests a point source of PFOS in this area.

  10. Perfluorinated alkyl acids in the plasma of South African crocodiles (Crocodylus niloticus).

    PubMed

    Christie, Ian; Reiner, Jessica L; Bowden, John A; Botha, Hannes; Cantu, Theresa M; Govender, Danny; Guillette, Matthew P; Lowers, Russell H; Luus-Powell, Wilmien J; Pienaar, Danie; Smit, Willem J; Guillette, Louis J

    2016-07-01

    Perfluorinated alkyl acids (PFAAs) are environmental contaminants that have been used in many products for over 50 years. Interest and concern has grown since 2000 on the widespread presence of PFAAs, when it was discovered that PFAAs were present in wildlife samples around the northern hemisphere. Since then, several studies have reported PFAAs in wildlife from many locations, including the remote regions of Antarctica and the Arctic. Although there are a multitude of studies, few have reported PFAA concentrations in reptiles and wildlife in the Southern Hemisphere. This study investigated the presence of PFAAs in the plasma of Nile crocodiles (Crocodylus niloticus) from South Africa. Crocodiles were captured from five sites in and around the Kruger National Park, South Africa, and plasma samples examined for PFAAs. Perfluorooctane sulfonate (PFOS) was the most frequent PFAA detected; with median values of 13.5 ng/g wet mass in crocodiles. In addition to PFOS, long chain perfluorinated carboxylic acids were also detected. Correlations between total length and PFAA load were investigated, as were differences in PFAA accumulation between sexes. No correlations were seen between crocodile size, nor were there sex-related differences. Spatial differences were examined and significant differences were observed in samples collected from the different sites (p < 0.05). Flag Boshielo Dam had the highest PFOS measurements, with a median concentration of 50.3 ng/g wet mass, when compared to the other sites (median concentrations at other sites below 14.0 ng/g wet mass). This suggests a point source of PFOS in this area. PMID:27038902

  11. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  12. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  13. 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.

  14. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  15. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  16. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  17. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  18. Selective Alkylation of C-Rich Bulge Motifs in Nucleic Acids by Quinone Methide Derivatives.

    PubMed

    Lönnberg, Tuomas; Hutchinson, Mark; Rokita, Steven

    2015-09-01

    A quinone methide precursor featuring a bis-cyclen anchoring moiety has been synthesized and its capacity to alkylate oligonucleotide targets quantified in the presence and absence of divalent metal ions (Zn(2+) , Ni(2+) and Cd(2+) ). The oligonucleotides were designed for testing the sequence and secondary structure specificity of the reaction. Gel electrophoretic analysis revealed predominant alkylation of C-rich bulges, regardless of the presence of divalent metal ions or even the bis-cyclen anchor. This C-selectivity appears to be an intrinsic property of the quinone methide electrophile as reflected by its reaction with an equimolar mixture of the 2'-deoxynucleosides. Only dA-N1 and dC-N3 alkylation products were detected initially and only the dC adduct persisted for detection under conditions of the gel electrophoretic analysis.

  19. Water-induced coacervation of alkyl carboxylic acid reverse micelles: phenomenon description and potential for the extraction of organic compounds.

    PubMed

    Ruiz, Francisco-Javier; Rubio, Soledad; Pérez-Bendito, Dolores

    2007-10-01

    Coacervates made up of alkanoic (C8-C16) and alkenoic (C18) acid reverse micelles were described for the first time, and their potential for the extraction of organic compounds prior to liquid chromatography was examined. The coacervation process occurred in miscible binary mixtures of water and a variety of protic and aprotic solvents. The phase behavior of alkyl carboxylic acids was found to be a function of both the Hildebrand solubility parameter, delta, and the hydrogen-bonding capability of the solvent. The best solvents for analytical extractions were those featuring the lowest delta values. The phase behavior of alkyl carboxylic acid/water/tetrahydrofuran (THF) ternary systems as a function of component concentration, pH, ionic strength, and temperature was investigated. The efficiency and the time required for phase separation depended on the experimental procedure used (i.e., standing, centrifugation, stirring, and sonication). The formation of alkyl carboxylic acid reverse micelles in THF was proven using both hydrophilic fluorescent probes and scattered light measurements. The structure of the coacervates consisted of spherical droplets dispersed in a continuous phase. Phase volume ratios were a function of both alkyl carboxylic acid and THF concentration. The low volume obtained (e.g., 1.5 microL per mg of decanoic) compared to that obtained by other coacervates (e.g., 5.1 microL per mg of dodecane sulfonic acid and 11.3 microL per mg of Triton X-114) greatly improved the concentration factors reached by coacervation-based extractions. Parameters affecting the extraction efficiency were assessed. Analytes in a wide range of polarity were efficiently extracted on the basis of the hydrophobic (e.g., PAHs) and hydrogen bond (e.g., chlorophenols, bisphenols, pesticides, phthalates, nonionic surfactants, dyes, and photographic developers) interactions that reverse micelles can establish. The coacervates were compatible with the chromatographic determination

  20. A surprising substituent effect provides a superior boronic acid catalyst for mild and metal-free direct Friedel-Crafts alkylations and prenylations of neutral arenes.

    PubMed

    Ricardo, Carolynne L; Mo, Xiaobin; McCubbin, J Adam; Hall, Dennis G

    2015-03-01

    The development of more general and efficient catalytic processes for Friedel-Crafts alkylations is an important objective of interest toward the production of pharmaceuticals and commodity chemicals. Herein, 2,3,4,5-tetrafluorophenylboronic acid was identified as a potent air- and moisture-tolerant metal-free catalyst that significantly improves the scope of direct Friedel-Crafts alkylations of a variety of slightly activated and neutral arenes, including polyarenes, with allylic and benzylic alcohols. This method also provides a simple alternative for the direct installation of prenyl units commonly found in naturally occurring arenes. Alkylations with benzylic alcohols occur under exceptionally mild conditions. PMID:25678266

  1. Heterogeneous catalysis by solid superacids--14. Perfluorinated resinsulfonic acid (nafion-h) catalyzed Friedel-crafts alkylation of toluene and phenol with alkyl chloroformates and oxalates

    SciTech Connect

    Olah, G.A.; Meidar, D.; Malhotra, R.; Olah, J.A.; Narang, S.C.

    1980-01-01

    Product distributions obtained in the alkylation of toluene with methyl, ethyl, and isopropyl chloroformate and dimethyl oxalate and of phenol with methyl and ethyl chloroformate and dimethyl- and diethyloxalate.

  2. Magnesium Lewis Acid Assisted Oxidative Bromoetherification Involving Bromine Transfer from Alkyl Bromides with Aldehydes by Umpolung of Bromide.

    PubMed

    Moriyama, Katsuhiko; Nishinohara, Chihiro; Togo, Hideo

    2016-08-16

    An oxidative bromoetherification involving a bromine transfer from alkyl bromides upon reacting them with aldehydes in a Grignard reaction with a concurrent oxidation of bromide was developed to provide substituted tetrahydrofurans in high yields. This reaction, which proceeds through two types of bromine transfer, was promoted by the addition of a Brønsted acid. Mechanistic studies suggested that a magnesium Lewis acid activates hypobromate, which is generated in situ from the reaction of bromide and Oxone to improve the electrophilicity of the bromonium ion (Br(+) ) for the oxidative bromoetherification of alkenyl alcohols. Furthermore, the magnesium Lewis acid catalyzed oxidative bromoetherification of an alkenyl alcohol proceeded to provide a cyclization product in 92 % yield. PMID:27304660

  3. Magnesium Lewis Acid Assisted Oxidative Bromoetherification Involving Bromine Transfer from Alkyl Bromides with Aldehydes by Umpolung of Bromide.

    PubMed

    Moriyama, Katsuhiko; Nishinohara, Chihiro; Togo, Hideo

    2016-08-16

    An oxidative bromoetherification involving a bromine transfer from alkyl bromides upon reacting them with aldehydes in a Grignard reaction with a concurrent oxidation of bromide was developed to provide substituted tetrahydrofurans in high yields. This reaction, which proceeds through two types of bromine transfer, was promoted by the addition of a Brønsted acid. Mechanistic studies suggested that a magnesium Lewis acid activates hypobromate, which is generated in situ from the reaction of bromide and Oxone to improve the electrophilicity of the bromonium ion (Br(+) ) for the oxidative bromoetherification of alkenyl alcohols. Furthermore, the magnesium Lewis acid catalyzed oxidative bromoetherification of an alkenyl alcohol proceeded to provide a cyclization product in 92 % yield.

  4. Enantioselective Synthesis of α-Quaternary Amino Acids by Alkylation of Deprotonated α-Aminonitriles.

    PubMed

    Netz, Isabelle; Kucukdisli, Murat; Opatz, Till

    2015-07-01

    A series of α-quaternary arylglycines were prepared in high optical purity (up to 98% ee) by α-alkylation of deprotonated α-aminonitriles derived by the Strecker reaction from (4S,5S)-5-amino-2,2-dimethyl-4-phenyl-1,3-dioxane. The procedure includes only chromatographic purification of the final products and is devoid of chromatography or crystallization operations on intermediates to raise the optical purity. PMID:26024300

  5. Lewis Acid Catalyzed Friedel-Crafts Alkylation of Alkenes with Trifluoropyruvates.

    PubMed

    Xiang, Bin; Xu, Teng-Fei; Wu, Liang; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-05-01

    A Friedel-Crafts alkylation reaction of styrenes with trifluoropyruvates has been developed, which delivered allylic alcohols in excellent yields (up to 98%) using the Ni(ClO4)2·6H2O/bipyridine complex as a catalyst. The asymmetric reaction was catalyzed by the chiral Cu(OTf)2/bisoxazoline complex to afford the corresponding chiral allylic alcohols bearing trifluoromethylated quaternary stereogenic centers in moderate enantioselectivities (up to 75% ee). PMID:27028539

  6. A toxicological and dermatological assessment of aryl alkyl alcohol simple acid ester derivatives when used as fragrance ingredients.

    PubMed

    Belsito, D; Bickers, D; Bruze, M; Calow, P; Dagli, M L; Fryer, A D; Greim, H; Miyachi, Y; Saurat, J H; Sipes, I G

    2012-09-01

    The aryl alkyl alcohol simple acid ester derivatives (AAASAE) group of fragrance ingredients was critically evaluated for safety following a complete literature search of the pertinent data. For high end users, calculated maximum skin exposures vary widely from 0.01% to 4.17%. AAASAE exhibit a common route of primary metabolism by carboxylesterases resulting in the formation of the simple acid and an aryl alkyl alcohol. They have low acute toxicity. No significant toxicity was observed in repeat-dose toxicity tests. There was no evidence of carcinogenicity of benzyl alcohol when it was administered in the feed; gavage studies resulted in pancreatic carcinogenesis due to the corn oil vehicle. The AAASAE are not mutagenic in bacterial systems or in vitro in mammalian cells, and have little to no in vivo genotoxicity. Reproductive and developmental toxicity data show no indication of adverse effects on reproductive function and NOELs for maternal and developmental toxicity are far in excess of current exposure levels. The AAASAE are generally not irritating or sensitizing at the current levels of exposure. The Panel is of the opinion that there are no safety concerns regarding the AAASAE at the current levels of use and exposure.

  7. Antimicrobial activity of some alkyl esters of gallic acid (3,4,5,-trihydroxybenzoic acid) against Escherichia coli NCTC 5933 with particular reference to n-propyl gallate.

    PubMed

    Boyd, L; Beveridge, E G

    1981-01-01

    The growth inhibitory and bactericidal activities of eight alkyl esters of gallic acid towards Escherichia coli NCTC 5933 have been determined. A previously suggested role for gallic acid and its esters as shikimate antimetabolites could not be substantiated. No induction of gross changes in cell morphology was observed. Bactericidal activity was accompanied only be very slight leakage of general ionic materials from the bacteria. Propyl gallate did not appear to uncouple oxidative phosphorylation from respiration as indicated by its failure to stimulate proton translocation across the cytoplasmic membrane.

  8. Metallaphotoredox-catalysed sp3–sp3 cross-coupling of carboxylic acids with alkyl halides

    NASA Astrophysics Data System (ADS)

    Johnston, Craig P.; Smith, Russell T.; Allmendinger, Simon; MacMillan, David W. C.

    2016-08-01

    In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp3-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp2-hybridized species, the development of methods for sp3–sp3 bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp3–sp3 bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step- and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp3–sp3 coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp3–sp3 bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox protocol is

  9. Influence of Alkyl Chain Length and Structure on the Extraction of Copper(II) from Aqueous Acid by 5-Alkyl-2-hydroxybenzaldoximes in Hydrocarbon Solvents: Diffusion Coefficients of Extractants and Their Complexes.

    PubMed

    Ainscow; Aldalur; Beezer; Connor; Garbett; Mitchell; Page; Tindale; Turner; Willson

    1999-05-01

    Measurement of the kinetics of extraction of copper(II) by 19 different 5-alkyl-2-hydroxybenzaldoximes (alkyl is C7H15 and C9H19) from acidic (hydrogen sulfate buffer) aqueous solution in the range pH 3.4-2.0, into 20% v/v toluene in n-hexane is reported. The lowering of the interfacial tension has been measured in some cases. The solubility of the extractants in water has been measured spectrophotometrically. A modified Taylor-Aris dispersion technique has been used to measure the diffusion coefficients in n-hexane and Orfom SX7 of some of the extractants and of the copper(II) complexes which they form. At low initial bulk concentrations (<10 mol m-3) of the extractants, the rate of extraction is controlled by the rate of diffusion of the extractant from the bulk to the organic-aqueous interface. The diffusion coefficient is related to the steric bulk of the alkyl substituent. At higher initial bulk concentrations (200 mol m-3) of the extractants, when the interface is saturated, the rate of extraction is inversely related to the apparent steric bulk of the alkyl substituent. Copyright 1999 Academic Press.

  10. GC separation of enantiomers of alkyl esters of 2-bromo substituted carboxylic acids enantiomers on 6-TBDMS-2,3-di-alkyl- β- and γ-cyclodextrin stationary phases.

    PubMed

    Spánik, Ivan; Kačeriaková, Darina; Krupčík, Jan; Armstrong, Daniel Wayne

    2014-06-01

    The gas chromatographic separation of enantiomers of 2-Br carboxylic acid derivatives was studied on four different 6-TBDMS-2,3-di-O-alkyl- β- and -γ-CD stationary phases. The differences in thermodynamic data {ΔH and -ΔS} for the 15 structurally related racemates were evaluated. The influence of structure differences in the alkyl substituents covalently attached to the stereogenic carbon atom, as well as in the ester group of the homologous analytes, and the selectivity of modified β- and γ- cyclodextrin derivatives was studied in detail. The cyclodextrin cavity size, as well as elongation of alkyl substituents in positions 2 and 3 of 6-TBDMS-β-CD, also affected their selectivity. The quality of enantiomeric separations is influenced mainly by alkyl chains of the ester group of the molecule and this appears to be independent of the CD stationary phase used. In some cases the separations occur as the result of external adsorption rather than inclusion complexations with the chiral selector. It was found that the temperature dependencies of the selectivity factor were nonlinear.

  11. Nitrated Fatty Acids Reverse Cigarette Smoke-Induced Alveolar Macrophage Activation and Inhibit Protease Activity via Electrophilic S-Alkylation

    PubMed Central

    Reddy, Aravind T.; Lakshmi, Sowmya P.; Muchumarri, Ramamohan R.; Reddy, Raju C.

    2016-01-01

    Nitrated fatty acids (NFAs), endogenous products of nonenzymatic reactions of NO-derived reactive nitrogen species with unsaturated fatty acids, exhibit substantial anti-inflammatory activities. They are both reversible electrophiles and peroxisome proliferator-activated receptor γ (PPARγ) agonists, but the physiological implications of their electrophilic activity are poorly understood. We tested their effects on inflammatory and emphysema-related biomarkers in alveolar macrophages (AMs) of smoke-exposed mice. NFA (10-nitro-oleic acid or 12-nitrolinoleic acid) treatment downregulated expression and activity of the inflammatory transcription factor NF-κB while upregulating those of PPARγ. It also downregulated production of inflammatory cytokines and chemokines and of the protease cathepsin S (Cat S), a key mediator of emphysematous septal destruction. Cat S downregulation was accompanied by decreased AM elastolytic activity, a major mechanism of septal destruction. NFAs downregulated both Cat S expression and activity in AMs of wild-type mice, but only inhibited its activity in AMs of PPARγ knockout mice, pointing to a PPARγ-independent mechanism of enzyme inhibition. We hypothesized that this mechanism was electrophilic S-alkylation of target Cat S cysteines, and found that NFAs bind directly to Cat S following treatment of intact AMs and, as suggested by in silico modeling and calculation of relevant parameters, elicit S-alkylation of Cys25 when incubated with purified Cat S. These results demonstrate that NFAs’ electrophilic activity, in addition to their role as PPARγ agonists, underlies their protective effects in chronic obstructive pulmonary disease (COPD) and support their therapeutic potential in this disease. PMID:27119365

  12. Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

    NASA Astrophysics Data System (ADS)

    Jiang, Tingshun; Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

    2014-10-01

    Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO42-/Zr-MCM-48 and SO42-/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH3-TPD and N2 physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO42-/Zr-MCM-48 and SO42-/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)-MCM-48 samples, SO42-/Zr-MCM-48 and SO42-/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO42-/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h-1 and the reaction temperature is 140 °C.

  13. Rapid determination of four short-chain alkyl mercapturic acids in human urine by column-switching liquid chromatography-tandem mass spectrometry.

    PubMed

    Eckert, Elisabeth; Göen, Thomas

    2014-08-15

    We developed and validated an analytical method for the simultaneous determination of methyl mercapturic acid (MeMA), ethyl mercapturic acid (EtMA), n-propyl mercapturic acid (PrMA) and iso-propyl mercapturic acid (iPrMA) in human urine. These alkyl mercapturic acids are known or presumed biomarkers of exposure to several alkylating agents including methyl bromide, dimethyl sulfate, ethyl bromide, 1-bromopropane and 2-bromopropane. The method involves a column switching arrangement for online solid phase extraction of the analytes with subsequent analytical separation and detection using liquid chromatography and tandem mass spectrometry. Within day and day-to-day imprecision was determined to range from 4.5 to 12.2%. The analytical method is distinguished by its wide linear working range of up to 2,500 μg/L with detection limits ranging from 2.0 μg/L (for PrMA) to 5.1 μg/L (for MeMA) that render possible the application in various biomonitoring studies regarding exposure to alkylating agents. The results of a pilot study on urine samples of 30 individuals occupationally non-exposed to alkylating agents using the new procedure confirmed the background excretion of MeMA (<5.1-35.6 μg/L) and PrMA (<2.0-95.7 μg/L).

  14. Extraction of manganese by alkyl monocarboxylic acid in a mixed extractant from a leaching solution of spent lithium-ion battery ternary cathodic material

    NASA Astrophysics Data System (ADS)

    Joo, Sung-Ho; Shin, Dongju; Oh, ChangHyun; Wang, Jei-Pil; Shin, Shun Myung

    2016-02-01

    We investigate the separation of manganese by an antagonistic effect from a leaching solution of ternary cathodic material of spent lithium-ion batteries that contain 11,400 mg L-1 Co, 11,700 mg L-1 Mn, 12,200 mg L-1 Ni, and 5300 mg L-1 Li using a mixture of alkyl monocarboxylic acid and di-(2-ethylhexyl)phosphoric acid extractants. pH isotherm, distribution coefficient, separation factor, McCabe-Thiele diagram, selective scrubbing, and countercurrent extraction tests are carried out to prove an antagonistic effect and to recover manganese using alkyl monocarboxylic in the mixed extractant. Slope analysis is used to determine the extraction mechanism between a mixture of extractants and valuable metals. An increasing concentration of alkyl monocarboxylic acid in the mixture of extractants results in a decrease in distribution coefficient of cobalt and manganese, however, the separation factor value (β(Mn/Co)) increases at pH 4.5. This is caused by slope analysis where alkyl monocarboxylic acid disrupts the extraction mechanism between di-(2-ethylhexyl)phosphoric acid and cobalt. Finally, continuous countercurrent extraction in a mini-plant test demonstrate the feasibility of manganese recovery from cobalt, nickel, and lithium.

  15. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  16. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  17. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  18. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  19. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  20. Fast and selective sugar conversion to alkyl lactate and lactic acid with bifunctional carbon-silica catalysts.

    PubMed

    de Clippel, Filip; Dusselier, Michiel; Van Rompaey, Ruben; Vanelderen, Pieter; Dijkmans, Jan; Makshina, Ekaterina; Giebeler, Lars; Oswald, Steffen; Baron, Gino V; Denayer, Joeri F M; Pescarmona, Paolo P; Jacobs, Pierre A; Sels, Bert F

    2012-06-20

    A novel catalyst design for the conversion of mono- and disaccharides to lactic acid and its alkyl esters was developed. The design uses a mesoporous silica, here represented by MCM-41, which is filled with a polyaromatic to graphite-like carbon network. The particular structure of the carbon-silica composite allows the accommodation of a broad variety of catalytically active functions, useful to attain cascade reactions, in a readily tunable pore texture. The significance of a joint action of Lewis and weak Brønsted acid sites was studied here to realize fast and selective sugar conversion. Lewis acidity is provided by grafting the silica component with Sn(IV), while weak Brønsted acidity originates from oxygen-containing functional groups in the carbon part. The weak Brønsted acid content was varied by changing the amount of carbon loading, the pyrolysis temperature, and the post-treatment procedure. As both catalytic functions can be tuned independently, their individual role and optimal balance can be searched for. It was thus demonstrated for the first time that the presence of weak Brønsted acid sites is crucial in accelerating the rate-determining (dehydration) reaction, that is, the first step in the reaction network from triose to lactate. Composite catalysts with well-balanced Lewis/Brønsted acidity are able to convert the trioses, glyceraldehyde and dihydroxyacetone, quantitatively into ethyl lactate in ethanol with an order of magnitude higher reaction rate when compared to the Sn grafted MCM-41 reference catalyst. Interestingly, the ability to tailor the pore architecture further allows the synthesis of a variety of amphiphilic alkyl lactates from trioses and long chain alcohols in moderate to high yields. Finally, direct lactate formation from hexoses, glucose and fructose, and disaccharides composed thereof, sucrose, was also attempted. For instance, conversion of sucrose with the bifunctional composite catalyst yields 45% methyl lactate in

  1. 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.

  2. General approach for the stereocontrolled construction of the beta-lactam ring in amino acid-derived 4-alkyl-4-carboxy-2-azetidinones.

    PubMed

    Gerona-Navarro, Guillermo; García-López, M Teresa; González-Muñiz, Rosario

    2002-05-31

    The first general approach toward the asymmetric synthesis of 4-alkyl-4-carboxy-2-azetidinones derived from amino acids is described. The stereoselective construction of the beta-lactam ring was achieved through base-mediated intramolecular cyclization of the corresponding N(alpha)-chloroacetyl derivatives bearing (+)- or (-)-10-(N,N-dicyclohexylsulfamoyl)isoborneol as chiral auxiliary (ee up to 82%).

  3. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2140 Carbo-poly-cycli-col...

  4. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2140 Carbo-poly-cycli-col...

  5. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2140 Carbo-poly-cycli-col...

  6. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2140 Carbo-poly-cycli-col...

  7. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2140 Carbo-poly-cycli-col...

  8. 40 CFR 721.10526 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide, polyfluorooctyl methacrylate and vinylidene chloride, 2,2'- hydrochloride (1:2)-initiated (generic). 721.10526 Section 721.10526...

  9. 40 CFR 721.10526 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide, polyfluorooctyl methacrylate and vinylidene chloride, 2,2'- hydrochloride (1:2)-initiated (generic). 721.10526 Section 721.10526...

  10. Asymmetric direct α-alkylation of 2-oxindoles with Michler's hydrol catalyzed by bis-cinchona alkaloid-Brønsted acid via an SN1-type pathway.

    PubMed

    Zhang, Tao; Qiao, Zhen; Wang, Yan; Zhong, Nengjun; Liu, Li; Wang, Dong; Chen, Yong-Jun

    2013-02-25

    An enantioselective direct α-alkylation of 2-oxindoles with Michler's hydrol via an S(N)1-type pathway in the non-covalent activation mode using the bis-cinchona alkaloid and Brønsted acid as a co-catalyst was developed and good to high yields and enantioselectivities were obtained.

  11. Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

    SciTech Connect

    Jiang, Tingshun Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

    2014-10-15

    Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH{sub 3}-TPD and N{sub 2} physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)–MCM-48 samples, SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO{sub 4}{sup 2−}/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h{sup −1} and the reaction temperature is 140 °C. - Highlights: • Sulfuric acid functional mesoporous solid acid catalysts were prepared via impregnation method. • The alkylation of phenol with tert-butyl alcohol was carried out over these solid acid catalysts. • The catalytic activity of SO{sub 4}{sup 2−}/Zr-MCM-48-25 catalyst is much higher than that of the others. • A maximum phenol conversion of 91.6% was achieved under optimum reaction conditions for SO{sub 4}{sup 2−}/Zr-MCM-48-25.

  12. Molecular design of boronic acid-functionalized squarylium cyanine dyes for multiple discriminant analysis of sialic acid in biological samples: selectivity toward monosaccharides controlled by different alkyl side chain lengths.

    PubMed

    Ouchi, Kazuki; Colyer, Christa L; Sebaiy, Mahmoud; Zhou, Jin; Maeda, Takeshi; Nakazumi, Hiroyuki; Shibukawa, Masami; Saito, Shingo

    2015-02-01

    We designed a new series of boronic acid-functionalized squarylium cyanine dyes (SQ-BA) with different lengths of alkyl chain residues, suitable for multiple discriminant analysis (MDA) of sialic acid (Neu5Ac) in biological samples. The SQ-BA dyes form aggregates based on hydrophobic interactions, which result in quenched fluorescence in aqueous solutions. When the boronic acid binds with saccharides, the fluorescence intensity increases as a result of dissociation to the emissive monomeric complex. We inferred that different dye aggregate structures (H-aggregates and J-aggregates) were induced depending on the alkyl chain length, so that monosaccharides would be recognized in different ways (especially, multipoint interaction with J-aggregates). A distinctive emission enhancement of SQ-BA dyes with shorter-alkyl-chains in the presence of Neu5Ac was observed (2.4-fold fluorescence enhancement; with formation constant 10(1.7) M(-1)), with no such enhancement for SQ-BA dyes with longer-alkyl-chain. In addition, various enhancement factors for other monosaccharides were observed depending on the alkyl chain length. Detailed thermodynamic and NMR studies of the SQ-BA complexes revealed the unique recognition mechanism: the dye aggregate with a shorter-alkyl-chain causes the slipped parallel structure and forms a stable 2:1 complex with Neu5Ac, as distinct from longer-alkyl-chain dyes, which form a 1:1 monomeric complex. MDA using the four SQ-BA dyes was performed for human urine samples, resulting in the successful discrimination between normal and abnormal Neu5Ac levels characteristic of disease. Thus, we successfully controlled various responses to similar monosaccharides with a novel approach that chemically modified not the boronic acid moiety itself but the length of the alkyl chain residue attached to the dye in order to generate specificity.

  13. Nitrosation of aspartic acid, aspartame, and glycine ethylester. Alkylation of 4-(p-nitrobenzyl)pyridine (NBP) in vitro and binding to DNA in the rat.

    PubMed

    Meier, I; Shephard, S E; Lutz, W K

    1990-05-01

    In a colorimetric assay using 4-(p-nitrobenzyl)pyridine (NBP) as a nucleophilic scavenger of alkylating agents, the nitrosation and alkylation reactions were investigated for a number of amino acids and derivatives. The alkylating activity increased with the square of the nitrite concentration. The nitrosation rate constants for aspartic acid, aspartame, and glycine ethylester (= precursors C) were 0.08, 1.4 and less than or equal to 0.2, respectively, expressed in terms of the pH-dependent k2 rate constant of the equation dNOC/dt = k2.[C].[nitrite]2. The rates correlated inversely with the basicity of the amino group. The stability of the alkylating activity was astonishingly high, both in acid and at neutral pH. Half-lives of 500, 200, and 30 min were determined for aspartic acid (pH 3.5), aspartame (pH 2.5), and glycine ethylester (pH 2.5). Values of 60, 15, and 2 min, respectively, were found at pH 7. It is concluded that rearrangement of the primary N-nitroso product to the ultimate alkylating agent could be rate-limiting. The potential of nitrosated alpha-amino acids to bind to DNA in vivo was investigated by oral gavage of radiolabelled glycine ethylester to rats, followed immediately by sodium nitrite. DNA was isolated from stomach and liver and analysed for radioactivity and modified nucleotides. No indication of DNA adduct formation was obtained. Based on an estimation of the dose fraction converted from glycine ethylester to the nitroso product under the given experimental conditions, the maximum possible DNA-binding potency of nitroso glycine ethylester is about one order of magnitude below the methylating potency of N-nitrosomethylurea in rat stomach. The apparent discrepancy to the in vitro data could be due to efficient detoxification processes in mammalian cells.

  14. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  15. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  16. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  17. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  18. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  19. Enhanced production of short-chain fatty acid from food waste stimulated by alkyl polyglycosides and its mechanism.

    PubMed

    Zhao, Jianwei; Yang, Qi; Li, Xiaoming; Wang, Dongbo; Luo, Kun; Zhong, Yu; Xu, Qiuxiang; Zeng, Guangming

    2015-12-01

    Short-chain fatty acids (SCFAs) are the valuable products derived from the anaerobic fermentation of organic solid waste. However, SCFAs yield was limited by the worse solubilization and hydrolysis of particulate organic matter, and rapid consumption of organic acid by methanogens. In this study, an efficient and green strategy, i.e. adding biosurfactant alkyl polyglycosides (APG) into anaerobic fermentation system, was applied to enhance SCFAs production from food waste. Experimental results showed that APG not only greatly improved SCFAs production but also shortened the fermentation time for the maximum SCFAs accumulation. The SCFAs yield at optimal APG dosage 0.2g/g TS (total solid) reached 37.2g/L, which was 3.1-fold of that in blank. Meanwhile, the time to accumulate the maximum SCFAs in the presence of APG was shortened from day 14 to day 6. The activities of key enzymes such as hydrolytic and acid-forming enzymes were greatly promoted due to the presence of APG. These results demonstrated that the enhanced mechanism of SCFAs production should be attributed to the acceleration of solubilization and hydrolysis, enhancement of acidification and inhibition of methanogenesis by APG. PMID:26342451

  20. Enhanced production of short-chain fatty acid from food waste stimulated by alkyl polyglycosides and its mechanism.

    PubMed

    Zhao, Jianwei; Yang, Qi; Li, Xiaoming; Wang, Dongbo; Luo, Kun; Zhong, Yu; Xu, Qiuxiang; Zeng, Guangming

    2015-12-01

    Short-chain fatty acids (SCFAs) are the valuable products derived from the anaerobic fermentation of organic solid waste. However, SCFAs yield was limited by the worse solubilization and hydrolysis of particulate organic matter, and rapid consumption of organic acid by methanogens. In this study, an efficient and green strategy, i.e. adding biosurfactant alkyl polyglycosides (APG) into anaerobic fermentation system, was applied to enhance SCFAs production from food waste. Experimental results showed that APG not only greatly improved SCFAs production but also shortened the fermentation time for the maximum SCFAs accumulation. The SCFAs yield at optimal APG dosage 0.2g/g TS (total solid) reached 37.2g/L, which was 3.1-fold of that in blank. Meanwhile, the time to accumulate the maximum SCFAs in the presence of APG was shortened from day 14 to day 6. The activities of key enzymes such as hydrolytic and acid-forming enzymes were greatly promoted due to the presence of APG. These results demonstrated that the enhanced mechanism of SCFAs production should be attributed to the acceleration of solubilization and hydrolysis, enhancement of acidification and inhibition of methanogenesis by APG.

  1. Polycarboxylates Enhance Beetle Antifreeze Protein Activity

    PubMed Central

    Amornwittawat, Natapol; Wang, Sen; Duman, John G.; Wen, Xin

    2008-01-01

    Summary Antifreeze proteins (AFPs) lower the noncolligative freezing point of water in the presence of ice below the ice melting point. The temperature difference between the melting point and the noncolligative freezing point is termed thermal hysteresis (TH). The magnitude of the TH depends on the specific activity and the concentration of AFP, and the concentration of enhancers in the solution. Known enhancers are certain low molecular mass molecules and proteins. Here, we investigated a series of polycarboxylates that enhance the TH activity of an AFP from the beetle Dendroides canadensis (DAFP) using differential scanning calorimetry (DSC). Triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetate, the most efficient enhancer identified in this work, can increase the TH of DAFP by nearly 1.5 fold over than that of the published best enhancer, citrate. The Zn2+ coordinated carboxylate results in loss of the enhancement ability of the carboxylate on antifreeze activity. There is not an additional increase in TH when a weaker enhancer is added to a stronger enhancer solution. These observations suggest that the more carboxylate groups per enhancer molecule the better the efficiency of the enhancer and that the freedom of motion of these molecules is necessary for them to serve as enhancers for AFP. The hydroxyl groups in the enhancer molecules can also positively affect their TH enhancement efficiency, though not as strongly as carboxylate groups. Mechanisms are discussed. PMID:18620083

  2. Study on the performance of polycarboxylate-based superplasticizers synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization

    NASA Astrophysics Data System (ADS)

    Yu, Binbin; Zeng, Zhong; Ren, Qinyu; Chen, Yang; Liang, Mei; Zou, Huawei

    2016-09-01

    A series of block type polycarboxylate-based superplasticizers (PCs) with different molecular architectures were synthesized with macromonomer butenyl alkylene polyoxyethylene-polyoxypropylene ether (BAPP) and acrylic acid (AA) by reversible addition-fragmentation chain transfer (RAFT) polymerization. Fourier-Transformed Infrared (FTIR) Spectroscopy and dynamic light scattering (DLS) were applied to investigate the PCs' molecular structure. The dispersion capacity of the PCs in cement were also measured, and the results showed that the polycarboxylic dispersing agents prepared by this method were suitable for portlant cement. It was found that the PCs could affect the hydration process, which was performed through retarding the generation of ettringite in the hydrated product. Our studies with X-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive strength measurement of hydrated production were all supporting this conclusion.

  3. Ruthenium-catalyzed alkylation of indoles with tertiary amines by oxidation of a sp3 C-H bond and Lewis acid catalysis.

    PubMed

    Wang, Ming-Zhong; Zhou, Cong-Ying; Wong, Man-Kin; Che, Chi-Ming

    2010-05-17

    Ruthenium porphyrins (particularly [Ru(2,6-Cl(2)tpp)CO]; tpp=tetraphenylporphinato) and RuCl(3) can act as oxidation and/or Lewis acid catalysts for direct C-3 alkylation of indoles, giving the desired products in high yields (up to 82% based on 60-95% substrate conversions). These ruthenium compounds catalyze oxidative coupling reactions of a wide variety of anilines and indoles bearing electron-withdrawing or electron-donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N-arylindoles to 3-{[(N-aryl-N-alkyl)amino]methyl}indoles (yield: up to 82%, conversion: up to 95%) and the alkylation of N-alkyl or N-H indoles to 3-[p-(dialkylamino)benzyl]indoles (yield: up to 73%, conversion: up to 92%). A tentative reaction mechanism involving two pathways is proposed: an iminium ion intermediate may be generated by oxidation of an sp(3) C-H bond of the alkylated aniline by an oxoruthenium species; this iminium ion could then either be trapped by an N-arylindole (pathway A) or converted to formaldehyde, allowing a subsequent three-component coupling reaction of the in situ generated formaldehyde with an N-alkylindole and an aniline in the presence of a Lewis acid catalyst (pathway B). The results of deuterium-labeling experiments are consistent with the alkylation of N-alkylindoles via pathway B. The relative reaction rates of [Ru(2,6-Cl(2)tpp)CO]-catalyzed oxidative coupling reactions of 4-X-substituted N,N-dimethylanilines with N-phenylindole (using tBuOOH as oxidant), determined through competition experiments, correlate linearly with the substituent constants sigma (R(2)=0.989), giving a rho value of -1.09. This rho value and the magnitudes of the intra- and intermolecular deuterium isotope effects (k(H)/k(D)) suggest that electron transfer most likely occurs during the initial stage of the oxidation of 4-X-substituted N,N-dimethylanilines. Ruthenium-catalyzed three-component reaction of N-alkyl/N-H indoles

  4. Synthesis of 5-aryl-1,3-dimethyl-6-(alkyl- or aryl-amino) furo [2,3-d]pyrimidine derivatives by reaction between isocyanides and pyridinecarbaldehydes in the presence of 1,3-dimethylbarbituric acid.

    PubMed

    Maghsoodlou, Malek Taher; Marandi, Ghasem; Hazeri, Nourallah; Habibi-Khorassani, Sayyed Mostafa; Mirzaei, Ali Akbar

    2011-02-01

    5-Aryl-6-(alkyl- or aryl-amino)-1,3-dimethylfuro [2,3-d]pyrimidine derivatives were obtained by in situ reaction alkyl or aryl isocyanides and pyridinecarbaldehyde derivatives in the presence of 1,3-dimethylbarbituric acid in dichloromethane without any prior activation or modifications.

  5. Behavioral effects of alpha-alkylated amino acid analogs in the C57BL/6J mouse.

    PubMed

    Sase, Ajinkya; Brückner, Hans; Höger, Harald; Pollak, Arnold; Lubec, Gert

    2013-09-01

    Although a series of amino acid analogs have been shown to modulate brain function, information on the pharmacology of alpha-alkylated amino acids (AAAA) is limited. In particular there is no information on the effect of these amino acid analogs (AAA) on the elevated plus maze, the tail suspension test and the forced swim test. It was therefore the aim of the study to test a series of AAAA in these paradigms in order to explore behavioral activities of this compound class. 10 male mice per group aged between 10 and 14 weeks were used. Vehicle-treated controls were used in addition to intraperitoneal injections of 1, 10 and 100mg/kg body weight of each, alpha-amino-isobutyic acid (AIB), isovaline (IVA), alpha-propyl-alanine (APA), alpha-butyl-alanine (ABA), alpha-pentyl-alanine (APnA), alpha-ethylphenylglycine (AEPG) and alpha-methyl-valine (AMV). The elevated plus maze (EPM), the tail suspension test (TST) and forced swim test (FST) were used for behavioral testing. There were dose-dependent results: all compounds increased time and pathlength in the open arm of the EPM at least at one dose administered. In the TST and in the FST only the 100mg dose was showing an effect. The results show pharmacological activity modifying the EPM in low doses suggesting the use in treatment of behavioral traits and symptoms represented by or linked to the EPM including anxiety-related behavior including depression. Compounds acting at higher doses may be used to induce behavioral changes and thus serve as neurobiological-neuropharmacological tools. PMID:23756141

  6. Inhibition of amyloid fibril formation of human amylin by N-alkylated amino acid and alpha-hydroxy acid residue containing peptides.

    PubMed

    Rijkers, Dirk T S; Höppener, Jo W M; Posthuma, George; Lips, Cornelis J M; Liskamp, Rob M J

    2002-09-16

    Amyloid deposits are formed as a result of uncontrolled aggregation of (poly)peptides or proteins. Today several diseases are known, for example Alzheimer's disease, Creutzfeldt-Jakob disease, mad cow disease, in which amyloid formation is involved. Amyloid fibrils are large aggregates of beta-pleated sheets and here a general method is described to introduce molecular mutations in order to achieve disruption of beta-sheet formation. Eight backbone-modified amylin derivatives, an amyloidogenic peptide involved in maturity onset diabetes, were synthesized. Their beta-sheet forming properties were studied by IR spectroscopy and electron microscopy. Modification of a crucial amide NH by an alkyl chain led to a complete loss of the beta-sheet forming capacity of amylin. The resulting molecular mutated amylin derivative could be used to break the beta-sheet thus retarding beta-sheet formation of unmodified amylin. Moreover, it was found that the replacement of this amide bond by an ester moiety suppressed fibrillogenesis significantly. Introduction of N-alkylated amino acids and/or ester functionalities-leading to depsipeptides-into amyloidogenic peptides opens new avenues towards novel peptidic beta-sheet breakers for inhibition of beta-amyloid aggregation. PMID:12298020

  7. Solid-state NMR and DFT predictions of differences in COOH hydrogen bonding in odd and even numbered n-alkyl fatty acids.

    PubMed

    Powell, Jacob; Kalakewich, Keyton; Uribe-Romo, Fernando J; Harper, James K

    2016-05-14

    For nearly 140 years n-alkyl monocarboxylic acids have been known to exhibit unusual non-monotonic melting between odd and even numbered acids. This behavior has been rationalized in terms of packing density at the hydrocarbon tails, with COOH hydrogen bonding considered to be invariant among different acids. A recent ambiguity involving the COOH conformation between two crystal structures of lauric acid suggests that COOH structure and hydrogen bonding may play a role in these differences. Here, the two conflicting lauric acid crystal structures are further refined using lattice-including DFT refinement methods. Solid-state NMR (SSNMR) (13)C chemical shift tensor data are employed to monitor refinement quality by comparing experimental and computed tensors. This comparison provides a more sensitive measure of structure than X-ray data due to SSNMR's ability to accurately locate hydrogens. Neither diffraction structure agrees with SSNMR data and an alternative is proposed involving a hydrogen disordered COOH moiety. The disordered hydrogen dynamically samples two most probable positions on the NMR timescale with O-H bond lengths of 1.16 and 1.46 Å. This disordered structure is consistent with SSNMR, IR and X-ray C-O and C[double bond, length as m-dash]O bond lengths. The hydrogen disorder appears to be restricted to even numbered acids based on undecanoic acid's (13)COOH tensor data and C-O and C[double bond, length as m-dash]O bond lengths for other n-alkyl acids. This disorder in even numbered acids results in stronger hydrogen bonds than are found in odd acids and invites a reevaluation of the melting behavior of n-alkyl acids that includes these differences in hydrogen bonding.

  8. Solid-state NMR and DFT predictions of differences in COOH hydrogen bonding in odd and even numbered n-alkyl fatty acids.

    PubMed

    Powell, Jacob; Kalakewich, Keyton; Uribe-Romo, Fernando J; Harper, James K

    2016-05-14

    For nearly 140 years n-alkyl monocarboxylic acids have been known to exhibit unusual non-monotonic melting between odd and even numbered acids. This behavior has been rationalized in terms of packing density at the hydrocarbon tails, with COOH hydrogen bonding considered to be invariant among different acids. A recent ambiguity involving the COOH conformation between two crystal structures of lauric acid suggests that COOH structure and hydrogen bonding may play a role in these differences. Here, the two conflicting lauric acid crystal structures are further refined using lattice-including DFT refinement methods. Solid-state NMR (SSNMR) (13)C chemical shift tensor data are employed to monitor refinement quality by comparing experimental and computed tensors. This comparison provides a more sensitive measure of structure than X-ray data due to SSNMR's ability to accurately locate hydrogens. Neither diffraction structure agrees with SSNMR data and an alternative is proposed involving a hydrogen disordered COOH moiety. The disordered hydrogen dynamically samples two most probable positions on the NMR timescale with O-H bond lengths of 1.16 and 1.46 Å. This disordered structure is consistent with SSNMR, IR and X-ray C-O and C[double bond, length as m-dash]O bond lengths. The hydrogen disorder appears to be restricted to even numbered acids based on undecanoic acid's (13)COOH tensor data and C-O and C[double bond, length as m-dash]O bond lengths for other n-alkyl acids. This disorder in even numbered acids results in stronger hydrogen bonds than are found in odd acids and invites a reevaluation of the melting behavior of n-alkyl acids that includes these differences in hydrogen bonding. PMID:27087051

  9. Polycarboxylated microfillers incorporated into light-curable resin-based dental adhesives evoke remineralization at the mineral-depleted dentin.

    PubMed

    Wang, Zhejun; Shen, Ya; Haapasalo, Markus; Wang, Jiao; Jiang, Tao; Wang, Yining; Watson, Timothy F; Sauro, Salvatore

    2014-01-01

    This study aimed at evaluating the remineralizing properties of three experimental light-curable resin-based dental adhesives containing tailored polycarboxylated microfillers. A co-monomers blend was firstly formulated and then mixed with each of the following microfillers: polycarboxylated bioactive glass (PBAG), polycarboxylated calcium silicates (PCS), and polycarboxylated calcium silicates-doped brushite (PDP). The three experimental and a filler-free control resins were applied onto 10% orthophosphoric acid treated dentin discs and light cured. The specimens were soaked in artificial saliva (AS) for 3, 7, and 14 days. Dentin mineral variation was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and Raman spectroscopy. Confocal laser scanning microscopy (CLSM) was employed to observe the ultra-morphology/nanoleakage along the resin-dentin interface. The bonding ability and the durability of the resin-dentin bonds were investigated through microtensile bond strength (μTBS) test. ATR-FTIR and Raman showed a significant increase of the mineral matrix area ratio and phosphate peak intensity in specimens treated with the experimental resins within 14 days (p < 0.05). No significant increment of minerals was found in untreated specimens or specimens treated using the control filler-free resin (p > 0.05). Dentin treated using PBAG or PCS exhibited higher level of remineralization than the specimens in PDP group. CLSM showed reduction in nanoleakage, although the remineralization of the hybrid layer induced a significant drop in the μTBS after 3-month storage (p < 0.05). The experimental resin-based dental adhesives containing bioactive microfillers remineralize the resin-dentin interfaces when in intimate contact with biological fluids.

  10. A prospective clinical study of polycarboxylate cement in periapical surgery

    PubMed Central

    Ortega-Sánchez, Bárbara; García-Mira, Berta; Maestre-Ferrín, Laura; Peñarrocha-Oltra, David; Gay-Escoda, Cosme

    2012-01-01

    Objective: To evaluate the clinical efficacy of polycarboxylate cement as retrograde filling material. Design: A prospective clinical study was made of 25 patients subjected to periapical surgery with ultrasound and magnifying loupes, in which polycarboxylate cement was used as retrograde filling material. Measurements were made of the area and diameter of the lesions pre- and postoperatively, and 6 and 12 months after the operation. The apical resection and retrograde filling areas were also measured, and the prognosis following surgery was recorded. Results: A total of 23 patients with 31 apicoectomized teeth were studied (2 patients being lost to follow-up). The mean area of the periapical lesions before surgery was 52.25 mm2, with a mean major diameter of 6.1 mm and a mean lesser diameter of 4.8 mm. The success rate after 12 months was 54.7%, according to the criteria of Von Arx and Kurt. The prognosis was poorer in females, in larger lesions, and in cases with larger retrograde filling areas. Conclusions: Polycarboxylate cement offers good results, with important bone regeneration after periapical surgery. Key words: Periapical surgery, endodontic treatment, polycarboxylate cement. PMID:22143701

  11. Alkyl polyglucose enhancing propionic acid enriched short-chain fatty acids production during anaerobic treatment of waste activated sludge and mechanisms.

    PubMed

    Luo, Jingyang; Feng, Leiyu; Chen, Yinguang; Sun, Han; Shen, Qiuting; Li, Xiang; Chen, Hong

    2015-04-15

    Adding alkyl polyglucose (APG) into an anaerobic treatment system of waste activated sludge (WAS) was reported to remarkably improve the production of short-chain fatty acids (SCFAs), especially propionic acid via simultaneously accelerating solubilization and hydrolysis, enhancing acidification, inhibiting methanogenesis and balancing carbon to nitrogen (C/N) ratio of substrate. Not only the production of SCFAs, especially propionic acid, was significantly improved by APG, but also the feasible operation time was shortened. The SCFAs yield at 0.3 g APG per gram of total suspended solids (TSS) within 4 d was 2988 ± 60 mg chemical oxygen demand (COD) per liter, much higher than that those from sole WAS or sole WAS plus sole APG. The corresponding yield of propionic acid was 1312 ± 25 mg COD/L, 7.9-fold of sole WAS. Mechanism investigation showed that during anaerobic treatment of WAS in the presence of APG both the solubilization and hydrolysis were accelerated and the acidification was enhanced, while the methanogenesis was inhibited. Moreover, the activities of key enzymes involved in WAS hydrolysis and acidification were improved through the adjustment of C/N ratio of substrates with APG. The abundance of microorganisms responsible for organic compounds hydrolysis and SCFAs production was also observed to be greatly enhanced with APG via 454 high-throughput pyrosequencing analysis.

  12. Chiral phosphoric acid catalyzed highly enantioselective Friedel-Crafts alkylation reaction of C3-substituted indoles to β,γ-unsaturated α-ketimino esters.

    PubMed

    Bi, Bo; Lou, Qin-Xin; Ding, Yu-Yang; Chen, Sheng-Wei; Zhang, Sha-Sha; Hu, Wen-Hui; Zhao, Jun-Ling

    2015-02-01

    A highly enantioselective C2 Friedel-Crafts alkylation reaction of 3-substituted indoles to β,γ-unsaturated α-ketimino esters has been developed. This reaction was efficiently catalyzed by a chiral phosphoric acid catalyst. The corresponding C2-substituted indole derivatives, bearing an α-ketimino ester motif, were obtained in moderate to high yields (up to 93%) and with high enantioselectivities (up to >99% ee). PMID:25594307

  13. Electrochemical method for producing a biodiesel mixture comprising fatty acid alkyl esters and glycerol

    DOEpatents

    Lin, YuPo J; St. Martin, Edward J

    2013-08-13

    The present invention relates to an integrated method and system for the simultaneous production of biodiesel from free fatty acids (via esterification) and from triglycerides (via transesterification) within the same reaction chamber. More specifically, one preferred embodiment of the invention relates to a method and system for the production of biodiesel using an electrodeionization stack, wherein an ion exchange resin matrix acts as a heterogeneous catalyst for simultaneous esterification and transesterification reactions between a feedstock and a lower alcohol to produce biodiesel, wherein the feedstock contains significant levels of free fatty acid. In addition, because of the use of a heterogeneous catalyst, the glycerol and biodiesel have much lower salt concentrations than raw biodiesel produced by conventional transesterification processes. The present invention makes it much easier to purify glycerol and biodiesel.

  14. Polyimides with pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1982-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  15. Acidic attack of perfluorinated alkyl ether lubricant molecules by metal oxide surfaces

    NASA Technical Reports Server (NTRS)

    Zehe, Michael J.; Faut, Owen D.

    1990-01-01

    The reactions of linear perfluoropolyalkylether (PFAE) lubricants with alpha-Fe203 and Fe203-based solid superacids were studied. The reaction with alpha-Fe203 proceeds in two stages. The first stage is an initial slow catalytic decomposition of the fluid. This reaction releases reactive gaseous products which attach the metal oxide and convert it to FeF3. The second stage is a more rapid decomposition of the fluid, effected by the surface FeF3. A study of the initial breakdown step was performed using alpha-Fe203, alpha-Fe203 preconverted to FeF3, and sulfate-promoted alpha-Fe203 superacids. The results indicate that the breakdown reaction involves acidic attack at fluorine atoms on acetal carbons in the linear PFAE. Possible approaches to combat the problem are outlined.

  16. Acidic attack of perfluorinated alkyl ether lubricant molecules by metal oxide surfaces

    NASA Technical Reports Server (NTRS)

    Zehe, Michael J.; Faut, Owen D.

    1989-01-01

    The reactions of linear perfluoropolyalkylether (PFAE) lubricants with alpha-Fe2O3 and Fe2O3-based solid superacids were studied. The reaction with alpha-Fe2O3 proceeds in two stages. The first stage is an initial slow catalytic decomposition of the fluid. This reaction releases reactive gaseous products which attach the metal oxide and convert it to FeF3. The second stage is a more rapid decomposition of the fluid, effected by the surface FeF3. A study of the inital breakdown step was performed using alpha-Fe2O3, alpha-Fe2O3 preconverted to FeF3, and sulfate-promoted alpha-Fe2O3 superacids. The results indicate that the breakdown reaction involves acidic attack at fluorine atoms on acetal carbons in the linear PFAE. Possible approaches to combat the problem are outlined.

  17. Kinetically and thermodynamically stable isomers of thorium chelates of polyaza polycarboxylic macrocycles

    NASA Astrophysics Data System (ADS)

    Jacques, Vincent; Desreux, Jean F.

    1994-10-01

    The solution conformation of the thorium(IV) complexes of two polyaza polycarboxylic macrocycles, DOTA and HEHA (1,4,7,10-tetraazacyclododecane-N, N', N(double prime), N(triple prime)-tetraacetic acid and 1,4,7,10,13,16-hexaazacyclooctadecane-N, N', N(double prime), N(triple prime), N(double prime)(double prime), N(double prime)(triple prime)-hexaacetic acid), was investigated by one- and two-dimensional nuclear magnetic resonance spectroscopy. ThHEHA(2+) forms a kinetically stable topomer of C2 symmetry and a thermodynamically stable topomer of S6 symmetry. Both complexes are assigned an icosahedral geometry. The activation energy for the intermolecular exchange is very high (214 kJ/mol). The behavior of ThHEHA(2+) contrasts with the properties of the other Th(IV) chelates that are known to be fluxional.

  18. Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina

    NASA Technical Reports Server (NTRS)

    Bangma, Jacqueline T.; Bowden, John A.; Brunell, Arnold M.; Christie, Ian; Finnell, Brendan; Guillette, Matthew P.; Jones, Martin; Lowers, Russell H.; Rainwater, Thomas R.; Reiner, Jessica L.; Wilkinson, Philip M.; Guillette, Louis J., Jr.

    2016-01-01

    This study aimed to quantitate fourteen perfluoroalkyl acids (PFAAs) in 125 adult American alligators at twelve sites across the southeastern US. Of those fourteen PFAAs, nine were detected in 65% - 100% of the samples: PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTriA, PFTA, PFHxS, and PFOS. Males (across all sites) showed significantly higher concentrations of four PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at Merritt Island National Wildlife Refuge and Kiawah Nature Conservancy both exhibited some of the highest PFOS concentrations (medians 99.5 ng/g and 55.8 ng/g respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length (SVL) were observed in both sexes suggesting PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. This study is the first to report PFAAs in American alligators, reveals potential PFAA hot spots in Florida and South Carolina, and provides and additional contaminant of concern when assessing anthropogenic impacts on ecosystem health.

  19. Determination of perfluorinated alkyl acid concentrations in biological standard reference materials.

    PubMed

    Reiner, Jessica L; O'Connell, Steven G; Butt, Craig M; Mabury, Scott A; Small, Jeff M; De Silva, Amila O; Muir, Derek C G; Delinsky, Amy D; Strynar, Mark J; Lindstrom, Andrew B; Reagen, William K; Malinsky, Michelle; Schäfer, Sandra; Kwadijk, Christiaan J A F; Schantz, Michele M; Keller, Jennifer M

    2012-11-01

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned for legacy pollutants. These SRMs can also serve as test materials for method development, method validation, and measurement for contaminants of emerging concern. Because inter-laboratory comparison studies have revealed substantial variability of measurements of perfluoroalkyl acids (PFAAs), future analytical measurements will benefit from determination of consensus values for PFAAs in SRMs to provide a means to demonstrate method-specific performance. To that end, NIST, in collaboration with other groups, has been measuring concentrations of PFAAs in a variety of SRMs. Here we report levels of PFAAs and perfluorooctane sulfonamide (PFOSA) determined in four biological SRMs: fish tissue (SRM 1946 Lake Superior Fish Tissue, SRM 1947 Lake Michigan Fish Tissue), bovine liver (SRM 1577c), and mussel tissue (SRM 2974a). We also report concentrations for three in-house quality-control materials: beluga whale liver, pygmy sperm whale liver, and white-sided dolphin liver. Measurements in SRMs show an array of PFAAs, with perfluorooctane sulfonate (PFOS) being the most frequently detected. Reference and information values are reported for PFAAs measured in these biological SRMs. PMID:22476786

  20. Alcohol Dimer is Requisite to Form an Alkyl Oxonium Ion in the Proton Transfer of a Strong (Photo)Acid to Alcohol.

    PubMed

    Park, Sun-Young; Lee, Young Min; Kwac, Kijeong; Jung, Yousung; Kwon, Oh-Hoon

    2016-03-18

    Alcohols, the simplest amphiprotic organic compounds, can exhibit either acidic or basic behavior by donating or accepting a proton. In this study, proton dissociation of a model photoacid in solution is explored by using time-resolved spectroscopy, revealing quantitatively for the first time that alcohol acts as a Brønsted base because of H-bonded cluster formation to enhance the reactivity. The protonated alcohol cluster, the alkyl oxonium ion, can be regarded as a key reaction intermediate in the well-established alcohol dehydration reaction. This finding signifies, as in water, the cooperativity of protic solvent molecules to facilitate nonaqueous acid-base reactions. PMID:26757097

  1. Lipase-catalyzed enantioselective synthesis of (R,R)-lactide from alkyl lactate to produce PDLA (poly D-lactic acid) and stereocomplex PLA (poly lactic acid).

    PubMed

    Jeon, Byoung Wook; Lee, Jumin; Kim, Hyun Sook; Cho, Dae Haeng; Lee, Hyuk; Chang, Rakwoo; Kim, Yong Hwan

    2013-10-20

    R-lactide, a pivotal monomer for the production of poly (D-lactic acid) (PDLA) or stereocomplex poly (lactic acid) (PLA) was synthesized from alkyl (R)-lactate through a lipase-catalyzed reaction without racemization. From among several types of lipase, only lipase B from Candida antarctica (Novozym 435; CAL-B) was effective in the reaction that synthesized (R,R)-lactide. Enantiopure (R,R)-lactide, which consisted of over 99% enantiomeric excess, was synthesized from methyl (R)-lactate through CAL-B catalysis. Removal of the methanol by-product was critical to obtain a high level of lactide conversion. The (R,R)-lactide yield was 56% in a reaction containing 100 mg of Novozym 435, 10 mM methyl (R)-lactate and 1500 mg of molecular sieve 5A in methyl tert-butyl ether (MTBE). The important monomer (R,R)-lactide that is required for the production of the widely recognized bio-plastic PDLA and the PLA stereocomplex can be obtained using this novel synthetic method.

  2. Alkylating enzymes.

    PubMed

    Wessjohann, Ludger A; Keim, Jeanette; Weigel, Benjamin; Dippe, Martin

    2013-04-01

    Chemospecific and regiospecific modifications of natural products by methyl, prenyl, or C-glycosyl moieties are a challenging and cumbersome task in organic synthesis. Because of the availability of an increasing number of stable and selective transferases and cofactor regeneration processes, enzyme-assisted strategies turn out to be promising alternatives to classical synthesis. Two categories of alkylating enzymes become increasingly relevant for applications: firstly prenyltransferases and terpene synthases (including terpene cyclases), which are used in the production of terpenoids such as artemisinin, or meroterpenoids like alkylated phenolics and indoles, and secondly methyltransferases, which modify flavonoids and alkaloids to yield products with a specific methylation pattern such as 7-O-methylaromadendrin and scopolamine.

  3. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia

    2009-09-22

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  4. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    SciTech Connect

    Ginosar, Daniel M.; Petkovic, Lucia M.

    2010-12-28

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  5. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-, metal salt (PMN P-04-498) is subject to reporting under this section for the significant new uses...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances §...

  6. Degradation of bisphenol A in water by Fe(III)/UVA and Fe(III)/polycarboxylate/UVA photocatalysis.

    PubMed

    Alvarez, P M; Rodríguez, E M; Fernández, G; Beltrán, F J

    2010-01-01

    The photodegradation of the endocrine disrupting chemical Bisphenol A (BPA) under UVA irradiation in the presence of Fe(III) or Fe(III)-polycarboxylate systems was studied. The effect of Fe(III) concentration, aqueous pH and the presence of four carboxylic acids (oxalic, malic, tartaric and citric) were investigated. The Fe(III)/UVA system was able to effectively degrade BPA at pH 3 but failed at pH > 4. At any rate, no mineralization of BPA was achieved with the Fe(III)/UVA system. The presence of carboxylic acids greatly enhanced the BPA degradation rate because of the formation of photoactive Fe(III)-polycarboxylate complexes. Aqueous pH in the 3-7 range exerted a negative effect on the BPA degradation rate and TOC conversion in the presence of oxalic, malic and tartaric acids. Only slight effect of pH was observed in the presence of citric acid, being the BPA degradation rate significant even at pH 7.

  7. Copper-Catalyzed Thioetherification Reactions of Alkyl Halides, Triphenyltin Chloride, and Arylboronic Acids with Nitroarenes in the Presence of Sulfur Sources.

    PubMed

    Rostami, Abed; Rostami, Amin; Ghaderi, Arash

    2015-09-01

    In this article, we report three odorless methods for the thioarylation and thioalkylation of different nitroarenes using alkyl halides (Br, Cl), triphenyltin chloride, and arylboronic acids as the coupling partners. Triphenyltin chloride is capable of delivering all of its phenyl groups to the product. Depending on the reaction, sodium thiosulfate pentahydrate (Na2S2O3·5H2O), S8/KF, and S8/NaOH systems are found to be effective sources of sulfur in the presence of copper salts. The use of green solvents, inexpensive catalysts, and user-friendly starting materials has made these methods interesting from a green chemistry standpoint. PMID:26272238

  8. Lubrication of Individual Microcontacts by a Self-Assembled Alkyl Phosphonic Acid Monolayer on α-Al2O3(0001).

    PubMed

    Paul, Jonas; Meltzer, Christian; Braunschweig, Björn; Peukert, Wolfgang

    2016-08-23

    We report on the tribological behavior of a self-assembled alkyl phosphonic acid monolayer on the microscale using the colloidal probe technique. Friction-load data and adhesion forces were measured with borosilicate glass particles on uncoated and octadecylphosphonic acid (ODPA) coated α-Al2O3(0001) surfaces. A significant decrease in friction force was observed after surface coating, while the adhesion force was only moderately reduced. We assume the lubrication effect of the ODPA self-assembled monolayer (SAM) to be close to the maximum obtainable of alkyl phosphonic acids in the studied system due to the high molecular order which was confirmed by vibrational sum-frequency generation. At small loads, a nonlinear dependence of friction force to load was maintained after surface coating. However, a shift from a contact behavior well described by the DMT model toward the JKR model occurred that is possibly related to the altered elastic properties of the coated surface. With increasing load, a linear friction-load behavior was observed on the coated samples. Molecular plowing and adhesive interactions were identified as responsible mechanisms. In all friction experiments, we could not detect any wear neither of the colloidal probes nor at the surfaces of uncoated and coated samples. This proves the high wear resistivity of the studied ODPA SAM. PMID:27478898

  9. Mass spectrometry of analytical derivatives. 1. Cyanide cations in the spectra of N- alkyl-N-perfluoroacyl- α-amino acids and their methyl esters.

    PubMed

    Todua, Nino G; Tretyakov, Kirill V; Mikaia, Anzor I

    2015-01-01

    The central mission for the development of the National Institute of Standards and Technology/National Institutes of Health/Environmental Protection Agency Mass Spectral Library is the acquisition of reference gas chromatography-mass spectrometry data for important compounds and their chemical modification products. The addition of reliable reference data of various derivatives of amino acids to The Library, and the study of their behavior under electron ionization conditions may be useful for their identification, structure elucidation and a better understanding of the data obtained when the same derivatives are subjected to other ionization methods. N-Alkyl-N-perfluoroacyl derivatives of amino acids readily produce previously unreported alkylnitrilium cations of composition [HC≡N-alkyl](+). Homologous [HC≡N-aryl](+) cations are typical for corresponding N-aryl analogs. The formation of other ions characteristic for these derivatives involves oxygen rearrangement giving rise to ions [C(n)F(2n+1)-C≡N(+)C(n)H(2n+1)] and [CnF(2n+1)-C≡N(+)-aryl]. The introduction of an N-benzyl substituent in a molecule favors a process producing benzylidene iminium cations. L-Threonine and L-cysteine derivatives exhibit more fragmentation pathways not typical for other α-amino acids; additionally, the N(ω)- amino group in L-lysine directs the dissociation process and provides structural information on the substitution at the amino functions in the molecule.

  10. Lubrication of Individual Microcontacts by a Self-Assembled Alkyl Phosphonic Acid Monolayer on α-Al2O3(0001).

    PubMed

    Paul, Jonas; Meltzer, Christian; Braunschweig, Björn; Peukert, Wolfgang

    2016-08-23

    We report on the tribological behavior of a self-assembled alkyl phosphonic acid monolayer on the microscale using the colloidal probe technique. Friction-load data and adhesion forces were measured with borosilicate glass particles on uncoated and octadecylphosphonic acid (ODPA) coated α-Al2O3(0001) surfaces. A significant decrease in friction force was observed after surface coating, while the adhesion force was only moderately reduced. We assume the lubrication effect of the ODPA self-assembled monolayer (SAM) to be close to the maximum obtainable of alkyl phosphonic acids in the studied system due to the high molecular order which was confirmed by vibrational sum-frequency generation. At small loads, a nonlinear dependence of friction force to load was maintained after surface coating. However, a shift from a contact behavior well described by the DMT model toward the JKR model occurred that is possibly related to the altered elastic properties of the coated surface. With increasing load, a linear friction-load behavior was observed on the coated samples. Molecular plowing and adhesive interactions were identified as responsible mechanisms. In all friction experiments, we could not detect any wear neither of the colloidal probes nor at the surfaces of uncoated and coated samples. This proves the high wear resistivity of the studied ODPA SAM.

  11. Mass spectrometry of analytical derivatives. 1. Cyanide cations in the spectra of N-alkyl-N-perfluoroacyl-α-amino acids and their methyl esters

    PubMed Central

    Todua, Nino G.; Tretyakov, Kirill V.; Mikaia, Anzor I.

    2016-01-01

    The central mission for the development of the National Institute of Standards and Technology/National Institutes of Health/Environmental Protection Agency Mass Spectral Library is the acquisition of reference gas chromatography–mass spectrometry data for important compounds and their chemical modification products. The addition of reliable reference data of various derivatives of amino acids to The Library, and the study of their behavior under electron ionization conditions may be useful for their identification, structure elucidation, and a better understanding of the data obtained when the same derivatives are subjected to other ionization methods. N-Alkyl-N-perfluoroacyl derivatives of amino acids readily produce previously unreported alkylnitrilium cations of composition [HC≡N-alkyl]+. Homologous [HC≡N-aryl]+ cations are typical for corresponding N-aryl analogs. The formation of other ions characteristic for these derivatives involves oxygen rearrangement giving rise to ions [CnF2n+1–C≡N+–CnH2n+1] and [CnF2n+1–C≡N+-aryl]. The introduction of an N-benzyl substituent in a molecule favors a process producing benzylidene iminium cations. l-Threonine and l-cysteine derivatives exhibit more fragmentation pathways not typical for other α-amino acids; additionally, the Nω-amino group in l-lysine directs the dissociation process and provides structural information on the substitution at the amino functions in the molecule. PMID:26307698

  12. N-Acyl Amino Acid Ligands for Ruthenium(II)-Catalyzed meta-C-H tert-Alkylation with Removable Auxiliaries.

    PubMed

    Li, Jie; Warratz, Svenja; Zell, Daniel; De Sarkar, Suman; Ishikawa, Eloisa Eriko; Ackermann, Lutz

    2015-11-01

    Acylated amino acid ligands enabled ruthenium(II)-catalyzed C-H functionalizations with excellent levels of meta-selectivity. The outstanding catalytic activity of the ruthenium(II) complexes derived from monoprotected amino acids (MPAA) set the stage for the first ruthenium-catalyzed meta-functionalizations with removable directing groups. Thereby, meta-alkylated anilines could be accessed, which are difficult to prepare by other means of direct aniline functionalizations. The robust nature of the versatile ruthenium(II)-MPAA was reflected by challenging remote C-H transformations with tertiary alkyl halides on aniline derivatives as well as on pyridyl-, pyrimidyl-, and pyrazolyl-substituted arenes. Detailed mechanistic studies provided strong support for an initial reversible C-H ruthenation, followed by a SET-type C-Hal activation through homolytic bond cleavage. Kinetic analyses confirmed this hypothesis through an unusual second-order dependence of the reaction rate on the ruthenium catalyst concentration. Overall, this report highlights the exceptional catalytic activity of ruthenium complexes derived from acylated amino acids, which should prove instrumental for C-H activation chemistry beyond remote functionalization.

  13. The AlkB Family of Fe(II)/α-Ketoglutarate-dependent Dioxygenases: Repairing Nucleic Acid Alkylation Damage and Beyond*

    PubMed Central

    Fedeles, Bogdan I.; Singh, Vipender; Delaney, James C.; Li, Deyu; Essigmann, John M.

    2015-01-01

    The AlkB family of Fe(II)- and α-ketoglutarate-dependent dioxygenases is a class of ubiquitous direct reversal DNA repair enzymes that remove alkyl adducts from nucleobases by oxidative dealkylation. The prototypical and homonymous family member is an Escherichia coli “adaptive response” protein that protects the bacterial genome against alkylation damage. AlkB has a wide variety of substrates, including monoalkyl and exocyclic bridged adducts. Nine mammalian AlkB homologs exist (ALKBH1–8, FTO), but only a subset functions as DNA/RNA repair enzymes. This minireview presents an overview of the AlkB proteins including recent data on homologs, structural features, substrate specificities, and experimental strategies for studying DNA repair by AlkB family proteins. PMID:26152727

  14. 1-Alkyl-1-methylpiperazine-1,4-diium salts: Synthetic, acid-base, XRD-analytical, FT-IR, FT-Raman spectral and quantum chemical study

    NASA Astrophysics Data System (ADS)

    Němečková, Dana; Mary, Y. Sheena; Panicker, C. Yohannan; Varghese, Hema Tresa; Van Alsenoy, Christian; Procházková, Markéta; Pazdera, Pavel; Al-Saadi, Abdulaziz A.

    2015-08-01

    We report the preparation and results of vibrational spectral analysis, which were obtained using both FT-IR and FT-Raman spectroscopy, for three 1-alkyl-1-methylpiperazine-1,4-diium salts (AMPSs), where alkyl is benzyl 4a, n-octadecyl 4b, and methyl 4c, respectively. These were prepared by multistep synthesis from piperazine. The acid-base study of AMPSs was performed and corresponding acid-base constants were obtained. Single crystals of AMPSs suitable for XRD-analysis were obtained and analyzed. The complete vibrational assignments of wavenumbers were made on the basis of a potential energy distribution. The HOMO and LUMO analysis was used to determine the charge transfer within the molecules. The calculated first hyperpolarizabilities of AMPSs 4a-4c are 48.34, 57.77 and 123.41 times that of urea. As can be seen from the MEP plots, the negative electrostatic potential regions are mainly localized over the chlorine and oxygen atoms for compounds 4a and 4b and chlorine and iodine atoms of compound 4c, and are possible sites for electrophilic attack.

  15. Evaluation of anti-herpetic and antioxidant activities, and cytotoxic and genotoxic effects of synthetic alkyl-esters of gallic acid.

    PubMed

    Savi, Luciane A; Leal, Paulo C; Vieira, Tiago O; Rosso, Rober; Nunes, Ricardo J; Yunes, Rosendo A; Creczynski-Pasa, Tânia B; Barardi, Célia R M; Simões, Cláudia M O

    2005-01-01

    The n-alkyl esters of gallic acid (CAS 13857-8) have a diverse range of uses as antioxidants in food, cosmetics and pharmaceutical industries. Pharmaceutical studies performed with these compounds have found that they have many therapeutic potentialities including anti-cancer, antiviral and antimicrobial properties. However, more interest has been devoted to their antioxidant activity due to the ability to scavenge and reduce reactive oxygen species (ROS) formation. In this study, gallic acid and 14 different alkyl gallates were tested. The cytotoxicity and anti-herpetic (HSV-1, KOS and 29-R strains) activity were studied by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay and the cell viability by using the Trypan blue dye exclusion method. The genotoxicity was studied by the Comet assay and the antioxidant activity by using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and microsomal lipid peroxidation-inhibiting activities. The results showed that all the tested compounds have anti-herpetic activity at non cytotoxic concentrations with selectivity indices (SI = CC50/EC50) varying from 0.89 to 18.34, depending on the used HSV-1 strain. It was observed that all tested alkyl gallates showed some degree of genotoxicity, at the tested concentrations, except cetyl gallate, at 256.60 micromol/L (p <0.05, t-Student test), probably induced by ROS released by infected cells and/or by the alkyl gallates that were not antioxidants, at the tested concentrations, in which they demonstrated anti-herpetic activity. The hydroxyl groups can induce DNA damage due interactions with some metal ions, which are naturally present in the culture medium supplemented with fetal bovine serum, probably explaining the genotoxicity detected. However, the obtained results showed considerable antioxidant activity at smaller concentrations, when compared to quercetin which is considered as a reference drug due to its already described

  16. Interconversion of biologically important carboxylic acids by radiation

    NASA Technical Reports Server (NTRS)

    Negron-Mendoza, A.; Ponnamperuma, C.

    1978-01-01

    The interconversion of a group of biologically important polycarboxylic acids (acetic, fumaric, malic, malonic, succinic, citric, isocitric, tricarballylic) under gamma-ray or ultraviolet radiation was investigated. The formation of high molecular weight compounds was observed in all cases. Succinic acid was formed in almost all radiolysis experiments. Citric, malonic, and succinic acids appeared to be relatively insensitive to radiation. Interconversion of the polycarboxylic acids studied may have occurred under the effect of radiation in the prebiotic earth.

  17. Fast analysis of flavonoids in plant extracts by liquid chromatography-ultraviolet absorbance detection on poly(carboxylic acid)-coated silica and electrospray ionization tandem mass spectrometric detection.

    PubMed

    Huck, C W; Buchmeiser, M R; Bonn, G K

    2002-01-11

    A highly hydrophilic poly(7-oxonorbornene-5,6-dicarboxylic acid-block-norbornene) [=poly-(ONDCA-b-NBE)]-coated silica was investigated for the liquid chromatographic (LC) determination of flavonoids in plant extracts of complex biological origin using UV absorbance and mass spectrometric (MS) detection. Compared to the most commonly used octadecyl derivatized silica this sorbent allowed fast separations even at extreme pH values. Furthermore, UV absorbance and MS detection were evaluated. As we found, UV detection at 254 nm allows the determination of flavonoids down to the ng range with a linearity of R2>0.9906. For the more selective characterization the validated LC system was coupled to a quadrupole ion trap mass spectrometer via an electrospray ionization (ESI) interface. MS detection showed high linearity (R2>0.9904) for all investigated flavonoids. Due to the relatively high flow-rate of 1 ml/min the limits of detection were found in the lower-microg range. Collision induced dissociation was applied to obtain characteristic fragmentation fingerprints. Finally, the validated LC-ESI-MS-MS method demonstrated that this poly-(ONDCA-b-NBE) stationary phase allows fast characterization and quantitation in onion, elderflower blossom, lime blossom, St. John's Wort and red wine.

  18. [3 + 2]-Annulations of N-alkyl-3-substituted indoles with quinone monoketals catalysed by Brønsted acids.

    PubMed

    Chai, Zhuo; Chen, Jia-Nan; Liu, Zhen; Li, Xue-Fei; Yang, Pei-Jun; Hu, Ji-Ping; Yang, Gaosheng

    2016-01-21

    An organocatalytic dearomative [3 + 2]-annulation of N-alkyl-3-alkylindoles with quinone monoketals is developed. The reaction provides a mild and straightforward way to various benzofuro[2,3-b]indolines of potential biological and pharmaceutical interest in moderate to good yields. Moreover, when 3-phenylindole, a problematic substrate in previous relevant studies, was used as the substrate under the otherwise same reaction conditions, a novel 1,2-shift of the phenyl group occurred followed by aromatization to provide 2,3-diaryl indoles useful for cancer therapy studies in moderate yields.

  19. Lactobionic acid as antioxidant and moisturizing active in alkyl polyglucoside-based topical emulsions: the colloidal structure, stability and efficacy evaluation.

    PubMed

    Tasic-Kostov, M; Pavlovic, D; Lukic, M; Jaksic, I; Arsic, I; Savic, S

    2012-10-01

    Cosmeceutical antioxidants may protect the skin against oxidative injury, involved in the pathogenesis of many skin disorders. However, an unsuitable topical delivery system with compromising safety profile can affect the efficacy of an antioxidant active. This study investigated the antioxidant potential of lactobionic acid (LA), a newer cosmeceutical active, per se (in solution) and incorporated into natural alkyl polyglucoside (APG) emulsifier-based system using 1,1-diphenyl-2-picrylhydrazyl free radical scavenging and lipid peroxidation inhibition assays. The α-tocopherol was used as a reference compound. The physical stability (using rheology, polarization microscopy, pH and conductivity measurements) of an Alkyl glucoside-based emulsion was evaluated with and without the active (LA); colloidal structure was assessed using polarization and transmission electron microscopy, rheology, thermal and texture analysis. Additionally, the safety profile and moisturizing potential were investigated using the methods of skin bioengineering. Good physical stability and applicative characteristics were obtained although LA strongly influenced the colloidal structure of the vehicle. LA per se and in APG-based emulsion showed satisfying antioxidant activity that promotes it as mild multifunctional cosmeceutical efficient in the treatment and prevention of the photoaged skin. Employed assays were shown as suitable for the antioxidant activity evaluation of LA in APG-based emulsions, but not for α-tocopherol in the same vehicle. PMID:22691034

  20. Effects of perfluorinated alkyl acids on cellular responses of MCF-10A mammary epithelial cells in monolayers and on acini formation in vitro.

    PubMed

    Halsne, Ruth; Tandberg, Julia Isabel; Lobert, Viola Hélène; Østby, Gunn Charlotte; Thoen, Even; Ropstad, Erik; Verhaegen, Steven

    2016-09-30

    Perfluorinated alkyl acids (PFAAs) are stable chemicals detected in tissue and serum from various species, including humans, and have been linked to adverse health outcomes. Experimental PFAA exposure in rodents has been associated with changes in mammary gland development. The estrogen receptor (ER)-negative human breast epithelial cell line, MCF-10A, can be grown as monolayer, but also has the ability to form three-dimensional acini in vitro, reflecting aspects of mammary glandular morphogenesis. Cells were exposed to five different PFAAs, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), both in monolayer and acini cultures. In monolayer cultures only the higher concentrations of PFOS, PFNA and PFDA (400-500μM) caused a significant increase in cell death, whereas PFOA and PFUnDA had no effect. Normal acini maturation was negatively impacted by PFOS, PFNA and PFDA already at the lowest concentration tested (0.6μM). Observed effects included loss of organization of the cell clusters and absence of a hollow lumen. Overall, this study demonstrated that PFAAs can interfere with cellular events related to normal development of glandular breast tissue through ER-independent mechanisms. PMID:27511595

  1. Efficient conversion of furfuryl alcohol into alkyl levulinates catalyzed by an organic-inorganic hybrid solid acid catalyst.

    PubMed

    Zhang, Zehui; Dong, Kun; Zhao, Zongbao Kent

    2011-01-17

    A clean, facile, and environment-friendly catalytic method has been developed for the conversion of furfuryl alcohol into alkyl levulinates making use of the novel solid catalyst methylimidazolebutylsulfate phosphotungstate ([MIMBS]₃PW₁₂O₄₀). The solid catalyst is an organic-inorganic hybrid material, which consists of an organic cation and an inorganic anion. A study for optimizing the reaction conditions such as the reaction time, the temperature and the catalyst loading has been performed. Under optimal conditions, a high n-butyl levulinate yield of up to 93 % is obtained. Furthermore, the kinetics of the reaction pathways and the mechanism for the alcoholysis of furfuryl alcohol are discussed. This method is environmentally benign and economical for the conversion of biomass-based derivatives into fine chemicals. PMID:21226220

  2. Interactions of /sup 14/N:/sup 15/N stearic acid spin-label pairs: effects of host lipid alkyl chain length and unsaturation

    SciTech Connect

    Feix, J.B.; Yin, J.J.; Hyde, J.S.

    1987-06-30

    Electron-electron double resonance (ELDOR) and saturation recovery electron paramagnetic resonance (EPR) spectroscopy have been employed to examine the interactions of /sup 14/N:/sup 15/N stearic acid spin-label pairs in fluid-phase model membrane bilayers composed of a variety of phospholipids. The (/sup 14/N)-16-doxylstearate:(/sup 15/N)-16-doxylstearate (16:16) pair was utilized to measure lateral diffusion of the spin-labels, while the (/sup 14/N)-16-doxylstearate:(/sup 15/N)-5-doxylstearate (16:5) pair provided information on vertical fluctuations of the 16-doxylstearate nitroxide moiety toward the membrane surface. Three saturated host lipids of varying alkyl chain length (dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC), and distearoylphosphatidylcholine (DSPC)), an ..cap alpha..-saturated, ..beta..-unsaturated lipid (1-palmitoyl-2-oleoylphosphatidylcholine (POPC)), and phosphatidylcholine from a natural source (egg yolk phosphatidylcholine (egg PC)) were utilized as host lipids. Lateral diffusion of the stearic acid spin-labels was only slightly affected by alkyl chain length at a given reduced temperature (T/sub r/) in the saturated host lipids but was significantly decreased in POPC at the same T/sub r/. Lateral diffusion in DMPC, POPC, and egg PC was quite similar at 37/sup 0/C. A strong correlation was noted between lateral diffusion constants and rotational mobility of (/sup 14/N)-16-doxylstearate. Vertical fluctuations were likewise only slightly influenced by alklyl chain length but were strongly diminished in POPC and egg PC relative to the saturated systems. This diminution of the 16:5 interaction was observed even under conditions where no differences were discernible by conventional EPR.

  3. Dielectric relaxation properties of carboxylic acid-terminated n-alkyl monolayers tethered to Si(1 1 1): dynamics of dipoles and gauche defects

    NASA Astrophysics Data System (ADS)

    Godet, C.

    2016-03-01

    Molecular-level insights into the organization and dynamics of n-alkyl monolayers covalently bonded to Si(1 1 1) were gained from admittance measurements of dipolar relaxation in rectifying Hg \\parallel HOOC-C10H25-n Si junctions performed as a function of applied voltage and temperature. A collective behavior of dipole dynamics is inferred from the non-Debye asymmetric relaxation peak shape and strong coupling of the dipole relaxation path with some bending vibrations of the n-alkyl OML (multi-excitation entropy model). A variety of relaxation mechanisms is observed in the frequency range (0.1 Hz-10 MHz) with different dependence of relaxation frequency and dipolar strength on measurement temperature and applied voltage. Their microscopic origin is discussed by comparing the activation energy of relaxation frequency with previous molecular mechanics calculations of saddle point energy barriers for structural defects such as gauche conformations or chain kinks in n-alkanes assemblies. Gauche conformations organized in pairs (kinks) have vanishing relaxation strength below an order-disorder transition temperature T D  =  175 K and their probability strongly increases with applied reverse voltage, above T D. The presence of hydrogen bonds between terminal carboxylic acid functionalities is inferred from a comparison with a similar junction bearing a low density of carboxylic acid end groups. This temperature-dependent hydrogen-bond network provides some additional stiffness against external electrostatic stress, as deduced from the rather weak sensitivity of relaxation frequencies to applied bias voltage.

  4. Methods of making alkyl esters

    SciTech Connect

    Elliott, Brian

    2010-08-03

    A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

  5. Influences of humic acid on the bioavailability of phenanthrene and alkyl phenanthrenes to early life stages of marine medaka (Oryzias melastigma).

    PubMed

    Liu, Yangzhi; Yang, Chenghu; Cheng, Pakkin; He, Xiaojing; Zhu, Yaxian; Zhang, Yong

    2016-03-01

    The influences of humic acid (HA) on the environmental behavior and bioavailability of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs were investigated and compared using the early life stages of marine medaka (Oryzias melastigma, O. melastigma). It was demonstrated that the binding affinity of parent phenanthrene (PHE) with HA was smaller than that of 3-methyl phenanthrene (3-MP) and 9-ethyl phenanthrene (9-EP). Furthermore, the bioaccumulation of the three PAHs and the levels of lipid peroxidation (LPO) were calculated to study the changes in bioavailability of PAHs in presence of HA. The results indicated that the addition of HA significantly decreased the bioaccumulation and toxicity of PAHs by decreasing free PAHs concentrations. The bioavailable fractions of HA-bound PAHs in bioaccumulation (α) and toxicity (β) were evaluated, indicating that the HA-bound 3-MP and 9-EP show higher bioavailability in bioaccumulation and lower bioavailability in toxicity relative to those of PHE. The β/α values were less than 1 for all PAH treatment groups containing HA, suggesting that the fraction of HA-bound PAHs contributing to bioaccumulation was higher than that of HA-bound PAHs inducing toxic effect. In addition, we proposed that the free PAHs generated by desorption from HA in the cell were toxic by showing that the β/α ratio values are correlated with the log KOW values (p = 0.007 and R(2) = 0.8355). Thus, oil spill risk assessments should consider both alkyl PAHs and the factors that influence the bioavailability and toxicity of PAHs in the natural aquatic environments.

  6. Identification of Reduction-Susceptible Disulfide Bonds in Transferrin by Differential Alkylation Using O16/O18 Labeled Iodoacetic Acid

    NASA Astrophysics Data System (ADS)

    Wang, Shunhai; Kaltashov, Igor A.

    2015-05-01

    Stabilization of native three-dimensional structure has been considered for decades to be the main function of disulfide bonds in proteins. More recently, it was becoming increasingly clear that in addition to this static role, disulfide bonds are also important for many other aspects of protein behavior, such as regulating protein function in a redox-sensitive fashion. Dynamic disulfide bonds can be taken advantage of as candidate anchor sites for site-specific modification (such as PEGylation of conjugation to a drug molecule), but are also frequently implicated in protein aggregation (through disulfide bond scrambling leading to formation of intermolecular covalent linkages). A common feature of all these labile disulfide bonds is their high susceptibility to reduction, as they need to be selectively regulated by either specific local redox conditions in vivo or well-controlled experimental conditions in vitro. The ability to identify labile disulfide bonds in a cysteine-rich protein can be extremely beneficial for a variety of tasks ranging from understanding the mechanistic aspects of protein function to identification of troublesome "hot spots" in biopharmaceutical products. Herein, we describe a mass spectrometry (MS)-based method for reliable identification of labile disulfide bonds, which consists of limited reduction, differential alkylation with an O18-labeled reagent, and LC-MS/MS analysis. Application of this method to a cysteine-rich protein transferrin allows the majority of its native disulfide bonds to be measured for their reduction susceptibility, which appears to reflect both solvent accessibility and bond strain energy.

  7. Gradient Measurements of NO, NO2, Total Peroxy Nitrates, Total Alkyl Nitrates, and Nitric Acid during BEARPEX-2009

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Lafranchi, B. W.; Min, K.; Browne, E. C.; Wooldridge, P. J.; Cohen, R. C.

    2009-12-01

    The Biosphere Effects on AeRosols and Photochemistry EXperiment (BEARPEX) provides a unique opportunity to examine biosphere-atmosphere exchange between the Sacramento urban plume and the low NOx high VOC conditions within a forest canopy. Within-canopy concentration gradients of nitrogen oxides evidence local forest-atmosphere interactions including chemical production and loss. Recent observations of NO2, total peroxy nitrates (ΣRO2NO2), total alkyl nitrates (ΣRONO2), and HNO3 fluxes suggest fast within-canopy photochemistry (Farmer and Cohen, 2008). During the BEARPEX-2009 campaign (June 18 - July 30), NO2, ΣRO2NO2, ΣRONO2, and HNO3 gradients were observed using thermal dissociation - laser induced fluorescence (TD-LIF) and collocated with NO chemiluminescence measurements within and above a ponderosa pine plantation in the Sierra Nevada Mountains of California. We report negative daytime gradients (lower concentrations near the surface) of ΣRONO2 and HNO3. At night, negative gradients of ΣRO2NO2 correspond to positive gradients in NO/NO2.

  8. Biphenyl-3-yl alkylcarbamates as fatty acid amide hydrolase (FAAH) inhibitors: Steric effects of N-alkyl chain on rat plasma and liver stability

    PubMed Central

    Vacondio, Federica; Silva, Claudia; Lodola, Alessio; Carmi, Caterina; Rivara, Silvia; Duranti, Andrea; Tontini, Andrea; Sanchini, Silvano; Clapper, Jason R.; Piomelli, Daniele; Tarzia, Giorgio; Mor, Marco

    2013-01-01

    Secondary alkylcarbamic acid biphenyl-3-yl esters are a class of Fatty Acid Amide Hydrolase (FAAH) inhibitors, which include the reference compounds URB597 and URB694. Given the intrinsic reactivity of the carbamate group, the in vivo potency of these molecules in rats is strongly affected by their hydrolysis in plasma or hepatic metabolism. In the present study, in vitro chemical and metabolic stability assays (rat plasma and rat liver S9 fraction) were used to investigate the structure-property relationships (SPRs) for a focused series of title compounds, where lipophilicity and steric hindrance of the carbamate N-substituent had been modulated. The resulting degradation rates indicate that a secondary or tertiary alkyl group at the carbamate nitrogen atom increases hydrolytic stability towards rat plasma esterases. The calculated solvent accessible surface area (SASA) of the carbamate fragment was employed to describe the differences observed in rate constants of hydrolysis in rat plasma (log kplasma), suggesting that stability in plasma increases if the substituent exerts a shielding effect on the carbamate carbonyl. Stability in rat liver S9 fraction is increased when a tertiary carbon is bound to the carbamate nitrogen atom, while other steric effects showed complex relationships with degradation rates. The SPRs here described may be applied at the pharmacokinetic optimization of other classes of carbamate FAAH inhibitors. PMID:21820769

  9. Synthesis of Fused Polycyclic Indoles by Brønsted Acid-Catalyzed Intramolecular Alkylation of Indoles with Alcohols.

    PubMed

    Suárez, Anisley; Gohain, Mukut; Fernández-Rodríguez, Manuel A; Sanz, Roberto

    2015-10-16

    An efficient methodology for the synthesis of a series of new fused polyclyclic indoles has been developed by Brønsted acid-catalyzed intramolecular Friedel-Crafts reactions of properly designed indolyl alcohols. PMID:26418556

  10. Regioselectivity of Birch reductive alkylation of biaryls.

    PubMed

    Lebeuf, Raphaël; Robert, Frédéric; Landais, Yannick

    2005-10-13

    [reaction: see text] The regioselectivity of the Birch reductive alkylation of polysubstituted biaryls has been investigated. Results indicate that regioselectivity is affected by the electronic nature of substituents on both aromatic rings. The electron-rich 3,5-dimethoxyphenyl moiety is selectively reduced and then alkylated, while phenols and aniline are not dearomatized under these conditions. Biaryls possessing a phenol moiety are alkylated on the second ring, providing that the acidic proton has been removed prior to the Li/NH3 reduction.

  11. Cytotoxicity of copper(II)-complexes with some S-alkyl derivatives of thiosalicylic acid. Crystal structure of the binuclear copper(II)-complex with S-ethyl derivative of thiosalicylic acid

    NASA Astrophysics Data System (ADS)

    Nikolić, Miloš V.; Mijajlović, Marina Ž.; Jevtić, Verica V.; Ratković, Zoran R.; Novaković, Slađana B.; Bogdanović, Goran A.; Milovanović, Jelena; Arsenijević, Aleksandar; Stojanović, Bojana; Trifunović, Srećko R.; Radić, Gordana P.

    2016-07-01

    The spectroscopically predicted structure of the obtained copper(II)-complex with S-ethyl derivative of thiosalicylic acid was confirmed by X-ray structural study and compared to previously reported crystal structure of the Cu complex with S-methyl derivative. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a water solution. Cytotoxic effects of S-alkyl (R = benzyl (L1), methyl (L2), ethyl (L3), propyl (L4) and butyl (L5)) derivatives of thiosalicylic acid and the corresponding binuclear copper(II)-complexes on murine colon carcinoma cell lines, CT26 and CT26.CL25 and human colon carcinoma cell line HCT-116 were reported here. The analysis of cancer cell viability showed that all the tested complexes had low cytotoxic effect on murine colon carcinoma cell lines, but several times higher cytotoxicity on normal human colon carcinoma cells.

  12. Nanostructured alkyl carboxylic acid-based restricted access solvents: Application to the combined microextraction and cleanup of polycyclic aromatic hydrocarbons in mosses.

    PubMed

    Caballero-Casero, N; Çabuk, H; Martínez-Sagarra, G; Devesa, J A; Rubio, S

    2015-08-26

    Alkyl carboxylic acid-based nanostructured solvents, synthesized in mixtures of tetrahydrofuran (THF) and water through self-assembly and coacervation, were proved to behave as restricted access liquids. Both physical and chemical mechanisms were found responsible for exclusion of macromolecules such as proteins and polysaccharides. The potential of these solvents for extracting small molecules from complex solid samples, without interference from large biomolecules, was here evaluated. For this purpose, they were applied to the extraction of 14 priority polycyclic aromatic hydrocarbons (PAHs) from mosses prior to their separation by liquid chromatography and fluorescence detection (LC-FLD). Sample treatment involved the vortex shaking of 200 mg of moss with 200 μL of decanoic acid-based solvent for 5 min, subsequent centrifugation for 8 min and analysis of the extract by LC-FLD using external calibration. Proteins precipitated during extraction because of both the decrease of the dielectric constant of the solution caused by THF and the formation of macromolecular complexes with decanoic acid. Polysaccharides were not solubilized in the aqueous cavities of the solvent because of their size exclusion. In-house method validation was performed according to the recommendations of the European Commission Decision 202/657/EC. Method detection and quantification limits for the different PAHs were in the ranges 0.04-0.24 and 0.14-0.80 μg kg(-1), respectively. The method was applied to the determination of different moss species collected in both polluted and unpolluted sites in the South of Spain. Recoveries were within the range 71-110%. The results obtained show that solvents with restricted access properties have the potential to expand the scope of application of restricted access materials to areas other than biological fluids because of their suitability to combine analyte isolation and sample cleanup of solid samples in a single step. PMID:26347174

  13. Nanostructured alkyl carboxylic acid-based restricted access solvents: Application to the combined microextraction and cleanup of polycyclic aromatic hydrocarbons in mosses.

    PubMed

    Caballero-Casero, N; Çabuk, H; Martínez-Sagarra, G; Devesa, J A; Rubio, S

    2015-08-26

    Alkyl carboxylic acid-based nanostructured solvents, synthesized in mixtures of tetrahydrofuran (THF) and water through self-assembly and coacervation, were proved to behave as restricted access liquids. Both physical and chemical mechanisms were found responsible for exclusion of macromolecules such as proteins and polysaccharides. The potential of these solvents for extracting small molecules from complex solid samples, without interference from large biomolecules, was here evaluated. For this purpose, they were applied to the extraction of 14 priority polycyclic aromatic hydrocarbons (PAHs) from mosses prior to their separation by liquid chromatography and fluorescence detection (LC-FLD). Sample treatment involved the vortex shaking of 200 mg of moss with 200 μL of decanoic acid-based solvent for 5 min, subsequent centrifugation for 8 min and analysis of the extract by LC-FLD using external calibration. Proteins precipitated during extraction because of both the decrease of the dielectric constant of the solution caused by THF and the formation of macromolecular complexes with decanoic acid. Polysaccharides were not solubilized in the aqueous cavities of the solvent because of their size exclusion. In-house method validation was performed according to the recommendations of the European Commission Decision 202/657/EC. Method detection and quantification limits for the different PAHs were in the ranges 0.04-0.24 and 0.14-0.80 μg kg(-1), respectively. The method was applied to the determination of different moss species collected in both polluted and unpolluted sites in the South of Spain. Recoveries were within the range 71-110%. The results obtained show that solvents with restricted access properties have the potential to expand the scope of application of restricted access materials to areas other than biological fluids because of their suitability to combine analyte isolation and sample cleanup of solid samples in a single step.

  14. 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.

  15. Dimensional modulation and magnetic properties of triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates

    SciTech Connect

    Zhang, Ju-Wen; Zhao, Wei; Lu, Qi-Lin; Luan, Jian; Qu, Yun; Wang, Xiu-Li

    2014-04-01

    Five new metal–organic coordination polymers ([Cu{sub 3}(μ{sub 2}-OH){sub 2}(atrz){sub 2}(nph){sub 2}(H{sub 2}O){sub 2}]·2H{sub 2}O){sub n} (1), ([Cu{sub 2}(μ{sub 3}-OH)(atrz)(1,2,4-btc)]·2H{sub 2}O){sub n} (2), ([Cu{sub 2}(μ{sub 3}-OH)(atrz)(1,2,4-btc)(H{sub 2}O)]·H{sub 2}O){sub n} (3), [Cu(dth){sub 0.5}(nph)(H{sub 2}O)]{sub n} (4) and [Cu(dth)(Hnip){sub 2}]{sub n} (5) [atrz=4-amino-1,2,4-triazole, dth=N,N'-di(4H-1,2,4-triazole)hexanamide, H{sub 2}nph=3-nitrophthalic acid, 1,2,4-H{sub 3}btc=1,2,4-benzenetricarboxylic acid and H{sub 2}nip=5-nitroisophthalic acid] were hydrothermally synthesized and structurally characterized. Polymer 1 shows a one-dimensional (1D) chain. Polymers 2 and 3 exhibit similar tetranuclear Cu{sup II}{sub 4} cluster-based three-dimensional (3D) frameworks with the same components. Polymer 4 possesses a 3D framework with a 4{sup 12}·6{sup 3}-pcu topology. Polymer 5 displays a 3D framework with a 4{sup 4}·6{sup 10}·8-mab topology. The magnetic properties of 1–4 were investigated. - Graphical abstract: Five triazole-based copper(II) polymers modulated by polycarboxylates were synthesized. Bis-triazole-bis-amide ligand and polycarboxylates play important roles in tuning dimensionality of polymers. Magnetic properties of polymers were investigated. - Highlights: • Five triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates were obtained. • The aromatic polycarboxylates have an important influence on the dimensionality of five polymers. • The magnetic properties of four polymers were investigated.

  16. 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.

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

    PubMed Central

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

    1971-01-01

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

  18. LATE POISONING WITH CHLOROFORM AND OTHER ALKYL HALIDES IN RELATIONSHIP TO THE HALOGEN ACIDS FORMED BY THEIR CHEMICAL DISSOCIATION

    PubMed Central

    Graham, Evarts A.

    1915-01-01

    The central lobular necrosis in the liver, which has been regarded by some writers as characteristic of late chloroform poisoning, has been produced experimentally with a number of other drugs. It is, therefore, in no sense peculiar to chloroform poisoning. Substances which have been shown to produce a morphological picture indistinguishable from that of late chloroform poisoning are: (a) dichlor- and tetrachlormethane, (b) tribrom- and triiodomethane, (c) monochlor-, monobrom-, and monoiodoethane, also the dibromethane; that is, in general, the halogen substituted aliphatic hydrocarbons containing one or two carbon atoms. Presumably similar results might be obtained with the higher members of the same series. The mechanism by which chloroform produces its characteristic tissue changes must accordingly be considered as a group reaction. Outside the body the similarities between the chemical behavior of different members of this group have been correlated by Nef on the basis of the type of dissociation which these substances undergo and the differences in their behavior on the basis of the differences of the degree to which such dissociations occur. According to the work of Nef, the group of substances under discussion has the property of dissociating to yield a halogen acid and an unsaturated alkylidene rest. Thus with chloroform the type of dissociation may be expressed thus: See PDF for Equation In this paper the view is developed that the changes characteristic of late poisonings with the above named group, namely edema, multiple hemorrhages, fat infiltration, and necrosis are ascribable (1) to acids and (2) to the fact that the amount of acid formed parallels the chemical dissociability of the drug outside of the body. Favoring the view that acid is responsible for the changes are the following observations. 1. All the characteristic features of late chloroform poisoning have been produced merely by the administration of hydrochloric acid, except, however, for

  19. 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.

  20. Dual Catalysis Using Boronic Acid and Chiral Amine: Acyclic Quaternary Carbons via Enantioselective Alkylation of Branched Aldehydes with Allylic Alcohols.

    PubMed

    Mo, Xiaobin; Hall, Dennis G

    2016-08-31

    A ferrocenium boronic acid salt activates allylic alcohols to generate transient carbocations that react with in situ-generated chiral enamines from branched aldehydes. The optimized conditions afford the desired acyclic products embedding a methyl-aryl quaternary carbon center with up to 90% yield and 97:3 enantiomeric ratio, with only water as the byproduct. This noble-metal-free method complements alternative methods that are incompatible with carbon-halogen bonds and other sensitive functional groups. PMID:27518200

  1. Gallic acid-based alkyl esters synthesis in a water-free system by celite-bound lipase of Bacillus licheniformis SCD11501.

    PubMed

    Sharma, Shivika; Kanwar, Shamsher S; Dogra, Priyanka; Chauhan, Ghanshyam S

    2015-01-01

    Gallic acid (3, 4, 5- trihydroxybenzoic acid) is an important antioxidant, anti-inflammatory, and radical scavenging agent. In the present study, a purified thermo-tolerant extra-cellular lipase of Bacillus licheniformis SCD11501 was successfully immobilized by adsorption on Celite 545 gel matrix followed by treatment with a cross-linking agent, glutaraldehyde. The celite-bound lipase treated with glutaraldehyde showed 94.8% binding/retention of enzyme activity (36 U/g; specific activity 16.8 U/g matrix; relative increase in enzyme activity 64.7%) while untreated matrix resulted in 88.1% binding/retention (28.0 U/g matrix; specific activity 8.5 U/g matrix) of lipase. The celite-bound lipase was successfully used to synthesis methyl gallate (58.2%), ethyl gallate (66.9%), n-propyl gallate (72.1%), and n-butyl gallate (63.8%) at 55(o) C in 10 h under shaking (150 g) in a water-free system by sequentially optimizing various reaction parameters. The low conversion of more polar alcohols such as methanol and ethanol into their respective gallate esters might be due to the ability of these alcohols to severely remove water from the protein hydration shell, leading to enzyme inactivation. Molecular sieves added to the reaction mixture resulted in enhanced yield of the alkyl ester(s). The characterization of synthesised esters was done through fourier transform infrared (FTIR) spectroscopy and (1) H NMR spectrum analysis.

  2. Comparative analysis for the production of fatty acid alkyl esterase using whole cell biocatalyst and purified enzyme from Rhizopus oryzae on waste cooking oil (sunflower oil).

    PubMed

    Balasubramaniam, Bharathiraja; Sudalaiyadum Perumal, Ayyappasamy; Jayaraman, Jayamuthunagai; Mani, Jayakumar; Ramanujam, Praveenkumar

    2012-08-01

    The petroleum fuel is nearing the line of extinction. Recent research and technology have provided promising outcomes to rely on biodiesel as the alternative and conventional source of fuel. The use of renewable source - vegetable oil constitutes the main stream of research. In this preliminary study, Waste Cooking Oil (WCO) was used as the substrate for biodiesel production. Lipase enzyme producing fungi Rhizopus oryzae 262 and commercially available pure lipase enzyme were used for comparative study in the production of Fatty Acid Alkyl Esters (FAAE). The whole cell (RO 262) and pure lipase enzyme (PE) were immobilized using calcium alginate beads. Calcium alginate was prepared by optimizing with different molar ratios of calcium chloride and different per cent sodium alginate. Entrapment immobilization was done for whole cell biocatalyst (WCB). PE was also immobilized by entrapment for the transesterification reaction. Seven different solvents - methanol, ethanol, n-propanol, n-butanol, iso-propanol, iso-butanol and iso-amyl alcohol were used as the acyl acceptors. The reaction parameters like temperature (30°C), molar ratio (1:3 - oil:solvent), reaction time (24 h), and amount of enzyme (10% mass ratio to oil) were also optimized for methanol alone. The same parameters were adopted for the other acyl acceptors too. Among the different acyl acceptors - methanol, whose reaction parameters were optimized showed maximum conversion of triglycerides to FAAE-94% with PE and 84% with WCB. On the whole, PE showed better catalytic converting ability with all the acyl acceptor compared to WCB. Gas chromatography analysis (GC) was done to determine the fatty acid composition of WCO (sunflower oil) and FAAE production with different acyl acceptors.

  3. Method of increasing conversion of a fatty acid to its corresponding dicarboxylic acid

    DOEpatents

    Craft, David L.; Wilson, C. Ron; Eirich, Dudley; Zhang, Yeyan

    2004-09-14

    A nucleic acid sequence including a CYP promoter operably linked to nucleic acid encoding a heterologous protein is provided to increase transcription of the nucleic acid. Expression vectors and host cells containing the nucleic acid sequence are also provided. The methods and compositions described herein are especially useful in the production of polycarboxylic acids by yeast cells.

  4. Characterization of the adsorption of omega-(thiophene-3-yl alkyl) phosphonic acid on metal oxides with AR-XPS.

    PubMed

    Adolphi, Barbara; Jähne, Evelin; Busch, Gernot; Cai, Xuediao

    2004-06-01

    The aim of the work discussed in this paper was to characterize adsorbed self-assembled monolayers on different metal oxide substrates with angle-resolved XPS measurements. The substrates used were silicon wafers (100) coated with 300 nm Al, Ta, or Ti. They were coated with acids by immersing them in an ethanol solution. The orientation of long-chain organic acids adsorbed on metal oxides has been successfully identified by angle-resolved XPS. On Al, Ta, and Ti substrates, C(11) chains are orientated in the right manner, i.e. with the phosphonic group at the bottom and the thiophene group on top. The orientations of the C(2) and C(6) chains are not clear. The thickness of the layers could be obtained by using Tougaard nanostructure analysis, and it shows monolayers. A model of the chemical bonds between the phosphonic group and the metal could be developed from the chemical shift. For titanium, all three P-O bonds bind to the metal substrate, whereas only the P-O(H) bond binds to the metal on aluminium and tantalum.

  5. Formation of highly stable self-assembled alkyl phosphonic acid monolayers for the functionalization of titanium surfaces and protein patterning.

    PubMed

    Han, Xuemingyue; Sun, Xiangyu; He, Tao; Sun, Shuqing

    2015-01-01

    A protocol for the preparation of improved phosphonate monolayers on a titanium (Ti) substrate is presented. Zirconium ions were used to enhance the bonding between the phosphonate headgroup and the pretreated Ti surface. Contact angle and X-ray photoelectron spectroscopy were used to characterize self-assembled monolayers (SAMs) of alkylphosphonic acid that formed spontaneously on Zr-mediated Ti (Zr/Ti) surfaces. The surfaces that were treated with an aqueous solution of zirconium oxychloride showed significantly enhanced stability in buffer compared with those formed directly on the native oxidized Ti. A bifunctional molecule, 10-mercaptodecanyl phosphonic acid (MDPA), was also used to form SAMs on Zr/Ti surfaces using an identical method, which enabled us to regulate the surface functionality through the terminal functional group. Protein patterning on the surface was carried out using UV irradiation through a mask to selectively degrade regions of the MDPA molecules. The surface was then backfilled with a protein-resistant molecule in the exposed regions followed by selective immobilization of proteins to the unexposed areas using a heterobifunctional linker molecule. The presented strategy significantly improved the stability of the phosphonate SAMs on oxidized Ti surfaces, which provided an ideal approach foundation for biomolecular immobilization and patterning onto the Ti surfaces. Thus, this method provided a versatile platform to activate the surfaces of biomedical Ti implants.

  6. In the Bottlebrush Garden: The Structural Aspects of Coordination Polymer Phases formed in Lanthanide Extraction with Alkyl Phosphoric Acids.

    PubMed

    Ellis, Ross J; Demars, Thomas; Liu, Guokui; Niklas, Jens; Poluektov, Oleg G; Shkrob, Ilya A

    2015-09-01

    Coordination polymers (CPs) of metal ions are central to a large variety of applications, such as catalysis and separations. These polymers frequently occur as amorphous solids that segregate from solution. The structural aspects of this segregation remain elusive due to the dearth of the spectroscopic techniques and computational approaches suitable for probing such systems. Therefore, there is a lacking of understanding of how the molecular building blocks give rise to the mesoscale architectures that characterize CP materials. In this study we revisit a CP phase formed in the extraction of trivalent lanthanide ions by diesters of the phosphoric acid, such as the bis(2-ethylhexyl)phosphoric acid (HDEHP). This is a well-known system with practical importance in strategic metals refining and nuclear fuel reprocessing. A CP phase, referred to as a "third phase", has been known to form in these systems for half a century, yet the structure of the amorphous solid is still a point of contention, illustrating the difficulties faced in characterizing such materials. In this study, we follow a deductive approach to solving the molecular structure of amorphous CP phases, using semiempirical calculations to set up an array of physically plausible models and then deploying a suite of experimental techniques, including optical, magnetic resonance, and X-ray spectroscopies, to consecutively eliminate all but one model. We demonstrate that the "third phase" consists of hexagonally packed linear chains in which the lanthanide ions are connected by three O-P-O bridges, with the modifying groups protruding outward, as in a bottlebrush. The tendency to yield linear polynuclear oligomers that is apparent in this system may also be present in other systems yielding the "third phase", demonstrating how molecular geometry directs polymeric assembly in hybrid materials. We show that the packing of bridging molecules is central to directing the structure of CP phases and that by

  7. Dual enhancement-inhibition roles of polycarboxylates in Cr(VI) reduction and organic pollutant oxidation in electrical plasma system.

    PubMed

    Jiang, Bo; Wang, Xianli; Hu, Ping; Wu, Mingbo; Zheng, Jingtang; Wu, Wenting

    2016-02-01

    In this study, the roles of polycarboxylates in synergistic Cr(VI) reduction and organic pollutant oxidation are investigated in glow discharge electrolysis (GDE). H2O2 generated in GDE plays a primary role for Cr(VI) reduction, and the presence of polycarboxylates can significantly enhance the reduction of Cr(VI) to Cr(III) with less value of [H2O2](consumption)/[Cr(VI)](reduction). Simultaneously, polycarboxylates inhibit the production of ·OH via chromium-based Fenton-like reaction, leading to the retarded oxidation of other pollutant oxidation, i.e., RhB. The formation of peroxochromate(V) is a requisite both for Cr(VI) reduction to Cr(III) and ·OH formation via Fenton-like reaction. Polycarboxylates can form complexes with peroxochromate(V), which can transform to Cr(III) spontaneously, thereby interrupting the pathway for additional ·OH production. These influences induced by polycarboxylate were found closely relative to the number and position of -OH group in polycarboxylates. Besides, 162.7 mg L(-1) Cr(VI) in actual electroplating effluent can be rapidly and almost completely reduced in GDE with introducing polycarboxylate containing nickel electroplating effluent. Generally, the present study provides a versatile strategy for Cr(VI) reduction, exhibiting a bright application future for real wastewater treatment. PMID:26517389

  8. A direct correlation between the antioxidant efficiencies of caffeic acid and its alkyl esters and their concentrations in the interfacial region of olive oil emulsions. The pseudophase model interpretation of the "cut-off" effect.

    PubMed

    Costa, Marlene; Losada-Barreiro, Sonia; Paiva-Martins, Fátima; Bravo-Díaz, Carlos; Romsted, Laurence S

    2015-05-15

    Recently published results for a series of homologous antioxidants, AOs, of increasing alkyl chain length show a maximum in AO efficiency followed by a significant decrease for the more hydrophobic AOs, typically called the "cut-off" effect. Here we demonstrate that in olive oil emulsions both antioxidant efficiencies and partition constants for distributions of AOs between the oil and interfacial regions, PO(I), show a maximum at the C8 ester. A reaction between caffeic acid, CA, and its specially synthesised C1-C16 alkyl esters, and a chemical probe is used to estimate partition constants for AO distributions and interfacial rate constants, kI, in intact emulsions based on the pseudophase kinetic model. The model provides a natural interpretation for both the maximum and the "cut-off" effect. More than 70% of the CA esters are in the interfacial region even at low surfactant volume fraction, ΦI=0.005.

  9. Occurrence of selected perfluorinated alkyl acids in lunch meals served at school canteens in Italy and their relevance for children's intake.

    PubMed

    Dellatte, Elena; Brambilla, Gianfranco; De Filippis, Stefania Paola; di Domenico, Alessandro; Pulkrabova, Jana; Eschauzier, Christian; Klenow, Stefanie; Heinemeyer, Gerhard; de Voogt, Pim

    2013-01-01

    Ready-to-eat servings may be more contaminated with perfluorinated alkyl acids (PFAAs) than the corresponding unprocessed foods due to the presence of PFAAs in and transfer from food contact materials (FCM) and cookware. Therefore, the presence of selected PFAAs in meals served weekly at lunch time in six Italian school canteens was assessed. Five towns were selected representing different areas with local water and food supply. Daily lunch menus were sampled and pooled to form a composite. Analyses were carried out on the weekly composite from each canteen. UPLC-MS/MS quantification limits were in the 6.0-12 pg g⁻¹ range for the selected PFAAs (PFHxA, PFOA, PFNA, PFDA, PFUnDA, PFHxS, branched and non-branched PFOS). Non-branched PFOS was quantified in four out of six composites, with levels ranging from 14 to 25 pg g⁻¹, while PFOA and PFDA were determined in two out of six in the range 6.5-8.2 pg g⁻¹. Theoretical estimates and analytical results in the same order of magnitude indicate a negligible contribution from food processing and serving to meal contamination. When composite analytical data are transposed into dietary estimates, it is shown that Italian school-age children have intakes in the range of 0.3-1.1 and 0.5-1.4 ng kg⁻¹ bw day⁻¹ for PFOA and PFOS respectively, well below the corresponding tolerable daily intakes (TDIs). PMID:23859821

  10. The Legionella pneumophila Siderophore Legiobactin Is a Polycarboxylate That Is Identical in Structure to Rhizoferrin

    PubMed Central

    Burnside, Denise M.; Wu, Yuyang; Shafaie, Saman

    2015-01-01

    Legionella pneumophila, the agent of Legionnaires' disease, secretes a siderophore (legiobactin) that promotes bacterial infection of the lung. In past work, we determined that cytoplasmic LbtA (from Legiobactin gene A) promotes synthesis of legiobactin, inner membrane LbtB aids in export of the siderophore, and outer membrane LbtU and inner membrane LbtC help mediate ferrilegiobactin uptake and assimilation. However, the past studies examined legiobactin contained within bacterial culture supernatants. By utilizing high-pressure liquid chromatography that incorporates hydrophilic interaction-based chemistry, we have now purified legiobactin from supernatants of virulent strain 130b that is suitable for detailed chemical analysis. High-resolution mass spectrometry (MS) revealed that the molecular mass of (protonated) legiobactin is 437.140 Da. On the basis of the results obtained from both MS analysis and various forms of nuclear magnetic resonance, we found that legiobactin is composed of two citric acid residues linked by a putrescine bridge and thus is identical in structure to rhizoferrin, a polycarboxylate-type siderophore made by many fungi and several unrelated bacteria. Both purified legiobactin and rhizoferrin obtained from the fungus Cunninghamella elegans were able to promote Fe3+ uptake by wild-type L. pneumophila as well as enhance growth of iron-starved bacteria. These results did not occur with 130b mutants lacking lbtU or lbtC, indicating that both endogenously made legiobactin and exogenously derived rhizoferrin are assimilated by L. pneumophila in an LbtU- and LbtC-dependent manner. PMID:26195554

  11. Syntheses, crystal structures, and properties of four complexes based on polycarboxylate and imidazole ligands

    NASA Astrophysics Data System (ADS)

    Qiao, Rui; Chen, Shui-Sheng; Sheng, Liang-Quan; Yang, Song; Li, Wei-Dong

    2015-08-01

    Four metal-organic coordination polymers [Zn(HL)(H2O)]·4H2O (1), [Zn(HL)(L1)]·4H2O (2), [Cu(HL)(H2O)]·3H2O (3) and [Cu(HL)(L1)]·5H2O (4) were synthesized by reactions of the corresponding metal(II) salts with semirigid polycarboxylate ligand (5-((4-carboxypiperidin-1-yl)methyl)isophthalic acid hydrochloride, H3L·HCl) or auxiliary ligand (1,4-di(1H-imidazol-4-yl)benzene, L1). The structures of the compounds were characterized by elemental analysis, FT-IR spectroscopy and single-crystal X-ray diffraction. The use of auxiliary ligand L1 has great influence on the structures of two pairs of complexes 1, 2 and 3, 4. Complex 1 is a uninodal 3-connected rare 2-fold interpenetrating ZnSc net with a Point (Schlafli) symbol of (103) while 2 is a one-dimensional (1D) ladder structure. Compound 3 features a two-dimensional (2D) honeycomb network with typical 63-hcb topology, while 4 is 2D network with (4, 4) sql topology based on binuclear CuII subunits. The non-covalent bonding interactions such as hydrogen bonds, π···π stacking and C-H···π exist in complexes 1-4, which contributes to stabilize crystal structure and extend the low-dimensional entities into high-dimensional frameworks. And the photoluminescent property of 1 and 2 and gas sorption property of 4 have been investigated.

  12. Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 2. Major structures

    USGS Publications Warehouse

    Leenheer, J.A.; Wershaw, R. L.; Reddy, M.M.

    1995-01-01

    Polycarboxylic acid structures that account for the strong-acid characteristics (pKa1 near 2.0) were examined for fulvic acid from the Suwannee River. Studies of model compounds demonstrated that pKa values near 2.0 occur only if the ??-ether or ??-ester groups were in cyclic structures with two to three additional electronegative functional groups (carboxyl, ester, ketone, aromatic groups) at adjacent positions on the ring. Ester linkage removal by alkaline hydrolysis and destruction of ether linkages through cleavage and reduction with hydriodic acid confirmed that the strong carboxyl acidity in fulvic acid was associated with polycarboxylic ??-ether and ??-ester structures. Studies of hypothetical structural models of fulvic acid indicated possible relation of these polycarboxylic structures with the amphiphilic and metal-binding properties of fulvic acid.

  13. Decarboxylative Alkyl-Alkyl Cross-Coupling Reactions.

    PubMed

    Konev, Mikhail O; Jarvo, Elizabeth R

    2016-09-12

    Alkyl with alkyl: A significant development in alkyl-alkyl cross-coupling reactions, namely the nickel-catalyzed decarboxylative Negishi coupling of N-hydroxyphthalimide esters, was recently reported by Baran and co-workers. This method enables the synthesis of various highly functionalized compounds, including natural product derivatives.

  14. PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

    DOEpatents

    Levine, C.A.; Skiens, W.E.; Moore, G.R.

    1960-08-01

    A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

  15. Alkylation of refinery C5 streams to lower gasoline volatility

    SciTech Connect

    Cronkright, W.A.; Ditz, J.M.; Newsome, D.S. ); Lerner, H. ); Schorfheide, J.J. ); Libbers, D.D. )

    1994-01-01

    A pilot plant program was carried out to provide precise information about the sulfuric acid alkylation of refinery C5 streams under conditions found in commercial operation of the Exxon stirred, autorefrigerated alkylation process. The study used isobutane to alkylate the full range of pentenes in a C5 cut from an FCC unit as well as the linear olefin concentrate in the raffinate that would be obtained after processing this cut in a TAME unit. A few experiments were conducted with a mixture of C5 olefins matching the composition of the refinery feed in order to highlight the effect of impurities. The results showed that hydrocarbon impurities are a principal factor causing the high acid consumption values reported for pentene alkylation. The results also demonstrated that operating variables that affect acid consumption and alkylate quality in butene alkylation produce directionally similar effects in pentene alkylation, but of different magnitude. It is concluded that sulfur acid alkylation of pentenes produces an excellent isoparaffinic blending stock for the gasoline pool while eliminating volatile olefins and reducing gasoline RVP. Combined with the TAME process, a scheme for adding oxygen and achieving maximum RVP reduction at the same time is realized.

  16. Antioxidant activity of alkyl gallates and glycosyl alkyl gallates in fish oil in water emulsions: relevance of their surface active properties and of the type of emulsifier.

    PubMed

    González, María J; Medina, Isabel; Maldonado, Olivia S; Lucas, Ricardo; Morales, Juan C

    2015-09-15

    The antioxidant activity of gallic acid and a series of alkyl gallates (C4-C18) and glycosylated alkyl gallates (C4-C18) on fish oil-in-water emulsions was studied. Three types of emulsifiers, lecithin, Tween-20 and sodium dodecyl sulphate (SDS) were tested. A nonlinear behavior of the antioxidant activity of alkyl gallates when increasing alkyl chain length was observed for emulsions prepared with lecithin. Medium-size alkyl gallates (C6-C12) were the best antioxidants. In contrast, for emulsions prepared with Tween-20, the antioxidants seem to follow the polar paradox. Glucosyl alkyl gallates were shown previously to be better surfactants than alkyl gallates. Nevertheless, they exhibited a worse antioxidant capacity than their corresponding alkyl gallates, in emulsions prepared with lecithin or Tween-20, indicating the greater relevance of having three OH groups at the polar head in comparison with having improved surfactant properties but just a di-ortho phenolic structure in the antioxidant.

  17. Alkylation of organic aromatic compounds

    DOEpatents

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

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  18. Alkylation of organic aromatic compounds

    DOEpatents

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

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  19. Xanthine oxidase inhibitory activity of alkyl gallates.

    PubMed

    Masuoka, Noriyoshi; Nihei, Ken-ichi; Kubo, Isao

    2006-08-01

    A series (C1-C12) of alkyl gallates was examined for their effects on the activity of xanthine oxidase. Octyl (C8), decyl (C10), and dodecyl (C12) gallates competitively inhibited uric acid formation generated by xanthine oxidase, and the inhibition increased upon increasing the alkyl chain length. Interestingly, neither menthyl nor bornyl gallates inhibited uric acid formation. These data indicate that the hydrophobic alkyl portion is associated with the xanthine-binding site in the Mo-binding domain. It is likely that the linear alkyl portion interacts with the hydrophobic domain close to the binding site, and the hydrophobic interaction is crucial to inhibit the xanthine oxidase reaction. On the other hand, all of gallic acid and its esters equally suppress superoxide anion generation catalyzed by xanthine oxidase at low concentration. The suppression is not due to scavenging activity of these gallates but due to reduction of xanthine oxidase by these gallates. The reduced enzyme catalyzes the reaction to generate hydrogen peroxide and uric acid.

  20. Effect of polycarboxylate ether comb-type polymer on viscosity and interfacial properties of kaolinite clay suspensions.

    PubMed

    Zhang, Ling; Lu, Qingye; Xu, Zhenghe; Liu, Qingxia; Zeng, Hongbo

    2012-07-15

    The interactions between kaolinite clay particles and a comb-type polymer (polycarboxylate ether or PCE), so-called PCE super-plasticizer, were investigated through viscosity and surface forces measurements by a rheometer and a Surface Forces Apparatus (SFA). The addition of PCE shows a strong impact on the viscosity of concentrated kaolinite suspensions in alkaline solutions (pH=8.3) but a weak effect under acidic conditions (pH=3.4). In acidic solutions, the high viscosity measured is attributed to the strong electrostatic interaction between negatively charged basal planes and positively charged edge surfaces of clay particles. Under the alkaline condition, the suspension viscosity was found to first increase significantly and then decrease with increasing PCE dosages. The results from surface forces measurement show that PCE molecules at low dosages can bridge the kaolinite particles in the concentrated suspensions via hydrogen bonding, leading to the formation of a kaolinite-PCE "network" and hence an increased suspension viscosity. At high PCE dosages, clay particles are fully covered by PCE molecules, leading to a more dispersed kaolinite suspensions and hence lower suspension viscosity due to steric repulsion between the adsorbed PCE molecules. The insights derived from measuring viscosity and interfacial properties of kaolinite suspensions containing varying amount of comb-type super-plasticizer PCE at different pH provide the foundation for many engineering applications and optimizing industrial processes. PMID:22591681

  1. Alkylation of organic aromatic compounds

    DOEpatents

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

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  2. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  3. Alkylation of organic aromatic compounds

    DOEpatents

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

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  4. Alkylation of organic aromatic compounds

    DOEpatents

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

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  5. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  6. Alkylation of organic aromatic compounds

    DOEpatents

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

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  7. Process for conversion of light paraffins to alkylate in the production of tertiary alkyl ether rich gasoline

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1992-04-21

    This patent describes a continuous integrated process for producing hydrocarbon streams comprising C{sub 5} + gasoline rich in alkyl tertiary alkyl ether and C{sub 5} + alkylated aromatic rich gasoline. It comprises contacting alkanol and C{sub 3} + aliphatic hydrocarbon stream containing alkanes and alkenes rich in iso-olefins with acid etherification catalyst under iso-olefin etherification conditions in an etherification reaction zone; separating etherification effluent to recover an overhead stream comprising unreacted alkanol plus C{sub 4} {minus} aliphatic hydrocarbons and a liquid product stream comprising C{sub 5} + gasoline containing alkyl tertiary-alkyl ether; contacting the overhead stream and a feedstream containing light aromatic hydrocarbons in an alkylation reactor containing acidic, medium pore metallosilicate catalyst under alkylation conditions and conversion conditions sufficient to convert alkanol, alkane and alkene to higher hydrocarbons the conditions comprising a temperature of about 200{degrees} C to 400{degrees} C and a pressure about above 3400 kPa; and separating step (c) reaction products and recovering the C{sub 5} + alkylated aromatic rich gasoline and a stream comprising C{sub 4} {minus} hydrocarbons.

  8. Zinc polycarboxylate dental cement for the controlled release of an active organic substance: proof of concept.

    PubMed

    Ali, Mohammad Naseem; Edwards, Mark; Nicholson, John W

    2010-04-01

    The potential of employing zinc polycarboxylate dental cement as a controlled release material has been studied. Benzalkonium chloride was used as the active ingredient, and incorporated at concentrations of 1, 2 and 3% by mass within the cement. At these levels, there was no observable effect on the speed of setting. Release was followed using an ion-selective electrode to determine changes in chloride ion concentration with time. This technique showed that the additive was released when the cured cement was placed in water, with release occurring by a diffusion mechanism for the first 3 h, but continuing beyond that for up to 1 week. Diffusion coefficients were in the range 5.62 x 10(-6) cm(2) s(-1) (for 1% concentration) to 10.90 x 10(-6) cm(2) s(-1) (for 3% concentration). Up to 3% of the total loading of benzalkonium chloride was released from the zinc polycarboxylate after a week, which is similar to that found in previous studies with glass-ionomer cement. It is concluded that zinc polycarboxylate cement is capable of acting as a useful material for the controlled release of active organic compounds.

  9. Syntheses, crystal structures, and properties of four complexes based on polycarboxylate and imidazole ligands

    SciTech Connect

    Qiao, Rui; Chen, Shui-Sheng; Sheng, Liang-Quan; Yang, Song; Li, Wei-Dong

    2015-08-15

    Four metal–organic coordination polymers [Zn(HL)(H{sub 2}O)]·4H{sub 2}O (1), [Zn(HL)(L{sub 1})]·4H{sub 2}O (2), [Cu(HL)(H{sub 2}O)]·3H{sub 2}O (3) and [Cu(HL)(L{sub 1})]·5H{sub 2}O (4) were synthesized by reactions of the corresponding metal(II) salts with semirigid polycarboxylate ligand (5-((4-carboxypiperidin-1-yl)methyl)isophthalic acid hydrochloride, H{sub 3}L·HCl) or auxiliary ligand (1,4-di(1H-imidazol-4-yl)benzene, L{sub 1}). The structures of the compounds were characterized by elemental analysis, FT-IR spectroscopy and single-crystal X-ray diffraction. The use of auxiliary ligand L{sub 1} has great influence on the structures of two pairs of complexes 1, 2 and 3, 4. Complex 1 is a uninodal 3-connected rare 2-fold interpenetrating ZnSc net with a Point (Schlafli) symbol of (10{sup 3}) while 2 is a one-dimensional (1D) ladder structure. Compound 3 features a two-dimensional (2D) honeycomb network with typical 6{sup 3}-hcb topology, while 4 is 2D network with (4, 4) sql topology based on binuclear Cu{sup II} subunits. The non-covalent bonding interactions such as hydrogen bonds, π···π stacking and C–H···π exist in complexes 1–4, which contributes to stabilize crystal structure and extend the low-dimensional entities into high-dimensional frameworks. And the photoluminescent property of 1 and 2 and gas sorption property of 4 have been investigated. - Graphical abstract: Four new coordination polymers have been obtained and their photoluminescent and gas sorption properties have also been investigated. - Highlights: • Two pairs of Zn{sup II}/ Cu{sup II} compounds have been synthesized. • Auxiliary ligand-controlled assembly of the complexes is reported. • The luminescent properties of complexes 1–2 were investigated. • The gas sorption property of 4 has been investigated.

  10. Spectroscopic and structural characterization of the charge-transfer interaction of N,N'-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide with chloranilic and picric acids

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; Ahmed, Hamdy A.; Grabchev, Ivo; El-Zayat, Lamia A.

    2008-09-01

    Charge-transfer (CT) complexes formed from the reactions of two N,N'-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide such as N, N'-bis[2-hydroxyethyl)]-1,4,6,8-naphthalenediimide (BHENDI) and N, N'-bis-[2- N, N-dimethylaminoethyl)]-1,4,6,8-naphthalenediimide (BDMAENDI) with chloranilic acid (CLA) and piciric acid (PA) as π-acceptors, have been studied spectrophotometrically in methanol and chloroform, respectively at 25 °C. The photometric titration curves for the reactions indicated that the data obtained refer to 1:1 charge-transfer complexes of [(BHENDI)(CLA)], [(BDMAENDI)(CLA)], [(BHENDI)(PA)] and [(BDMAENDI)(PA)] were formed. Benesi-Hildebrand and its modification methods were applied to the determination of association constant ( K), molar extinction coefficient ( ɛ). The solid CT complexes have been synthesized and characterization by different spectral methods.

  11. Polyimide characterization studies - Effect of pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1984-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  12. Lipoxygenase inhibitory activity of alkyl protocatechuates.

    PubMed

    Ha, Tae Joung; Shimizu, Kuniyoshi; Kubo, Isao

    2014-09-15

    Alkyl 3,4-dihydroxybenzoates (protocatechuates) inhibited linoleic acid peroxidation catalyzed by soybean lipoxygenase-1 (EC 1.13.11.12, Type 1). Their inhibitory activities displayed a parabolic function of their lipophilicity and maximized with alkyl chain lengths of between C11 and C14. Tetradecanyl protocatechuate exhibited the most potent inhibition with an IC50 of 0.05 μM, followed by dodecyl (lauryl) protocatechuate with an IC50 of 0.06 μM. However, their parent compound, protocatechuic acid, did not show this inhibitory activity up to 200 μM, indicating that the alkyl chain length is significantly related to the inhibition activity. The allosteric (or cooperative) inhibition of soybean lipoxygenase-1 of longer alkyl protocatechuates is reversible but in combination with their iron binding ability to disrupt the active site competitively and to interact with the hydrophobic portion surrounding near the active site (sequential action). In the case of dodecyl protocatechuate, the enzyme quickly binds this protocatechuate and then its dodecyl group undergoes a slow interaction with the hydrophobic domain in close proximity to the active site in the enzyme. The inhibition kinetics analyzed by Lineweaver-Burk plots indicates that octyl protocatechuate is a competitive inhibitor and the inhibition constant (Ki) was obtained as 0.23 μM but dodecyl protocatechuate is a slow binding inhibitor.

  13. Carbonic anhydrase inhibitors. A general approach for the preparation of water-soluble sulfonamides incorporating polyamino-polycarboxylate tails and of their metal complexes possessing long-lasting, topical intraocular pressure-lowering properties.

    PubMed

    Scozzafava, Andrea; Menabuoni, Luca; Mincione, Francesco; Supuran, Claudiu T

    2002-03-28

    Reaction of polyamino-polycarboxylic acids or their dianhydrides with aromatic/heterocyclic sulfonamides possessing a free amino/imino/hydrazino/hydroxy group afforded mono- and bis-sulfonamides containing polyamino-polycarboxylic acid moieties in their molecule. The acids/anhydrides used in synthesis included IDA, NTA, EDDA, EDTA and EDTA dianhydride, DTPA and DTPA dianhydride, EGTA and EGTA dianhydride, and EDDHA, among others. All the newly prepared derivatives showed strong affinity toward isozymes I, II, and IV of carbonic anhydrase (CA). Metal complexes of the new compounds have also been prepared. Metal ions used in such preparations included di- and trivalent main-group and transition cations, such as Zn(II), Cu(II), Al(III), etc. Some of the new sulfonamides/disulfonamides obtained in this way, as well as their metal complexes, behaved as nanomolar CA inhibitors against isozymes II and IV, being slightly less effective in inhibiting isozyme I. Some of these sulfonamides as well as their metal complexes strongly lowered intraocular pressure (IOP) when applied topically, directly into the normotensive/glaucomatous rabbit eye, as 1-2% water solutions/suspensions. The good water solubility of these sulfonamide CA inhibitors, correlated with the neutral pH of their water solutions used in the ophthalmologic applications and the long duration of action of the IOP-lowering effect, makes them interesting candidates for developing novel types of antiglaucoma drugs devoid of serious topical side effects. PMID:11906288

  14. 40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721.10679 Section 721... Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester... identified generically as carboxylic acid, substituted alkylstannylene ester, reaction products...

  15. Effect of olive storage conditions on Chemlali olive oil quality and the effective role of fatty acids alkyl esters in checking olive oils authenticity.

    PubMed

    Jabeur, Hazem; Zribi, Akram; Abdelhedi, Ridha; Bouaziz, Mohamed

    2015-02-15

    The present paper accounts for the study of the storage of Chemlali olive fruits at two conditions of limited aerobiosis: in closed plastic bags and in open perforated plastic boxes for different periods before oil extraction. The ultimate objective is to investigate the effect of the container type of the postharvest fruit storage on the deterioration of the olive oil quality. The results have shown that the oil quality of Chemlali olives deteriorated more rapidly during fruit storage in closed plastic bags than in perforated plastic boxes. Therefore, the use of perforated plastic boxes is recommended for keeping the olives for longer periods of storage. The repeated measures analysis of variance of all parameters analyzed indicated that the olive oil quality is mainly affected by the olives storage conditions (containers type and storage periods). Finally, blends of extra-virgin olive oil and mildly deodorized low-quality olive oils can be detected by their alkyl esters concentrations.

  16. Effect of olive storage conditions on Chemlali olive oil quality and the effective role of fatty acids alkyl esters in checking olive oils authenticity.

    PubMed

    Jabeur, Hazem; Zribi, Akram; Abdelhedi, Ridha; Bouaziz, Mohamed

    2015-02-15

    The present paper accounts for the study of the storage of Chemlali olive fruits at two conditions of limited aerobiosis: in closed plastic bags and in open perforated plastic boxes for different periods before oil extraction. The ultimate objective is to investigate the effect of the container type of the postharvest fruit storage on the deterioration of the olive oil quality. The results have shown that the oil quality of Chemlali olives deteriorated more rapidly during fruit storage in closed plastic bags than in perforated plastic boxes. Therefore, the use of perforated plastic boxes is recommended for keeping the olives for longer periods of storage. The repeated measures analysis of variance of all parameters analyzed indicated that the olive oil quality is mainly affected by the olives storage conditions (containers type and storage periods). Finally, blends of extra-virgin olive oil and mildly deodorized low-quality olive oils can be detected by their alkyl esters concentrations. PMID:25236229

  17. ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

    DOEpatents

    Long, R.L.

    1958-09-30

    A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

  18. Formation of furan fatty alkyl esters from their bis-epoxide fatty esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reactions of epoxidized alkyl soyate with four different alcohols: ethanol, isopropyl alcohol, 2-ethylhexanol, and benzyl alcohol were investigated in the presence of Bronsted acid catalyst. Products not reported in prior studies of similar reactions were found. These were furan fatty acid alkyl est...

  19. Determination of perfluorinated alkyl acids in corn, popcorn and popcorn bags before and after cooking by focused ultrasound solid-liquid extraction, liquid chromatography and quadrupole-time of flight mass spectrometry.

    PubMed

    Moreta, Cristina; Tena, María Teresa

    2014-08-15

    An analytical method is proposed to determine ten perfluorinated alkyl acids (PFAAs) [nine perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS)] in corn, popcorn and microwave popcorn packaging by focused ultrasound solid-liquid extraction (FUSLE) and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-time of flight mass spectrometry (QTOF-MS/MS). Selected PFAAs were extracted efficiently in only one 10-s cycle by FUSLE, a simple, safe and inexpensive technique. The developed method was validated for microwave popcorn bags matrix as well as corn and popcorn matrices in terms of linearity, matrix effect error, detection and quantification limits, repeatability and recovery values. The method showed good accuracy with recovery values around 100% except for the lowest chain length PFAAs, satisfactory reproducibility with RSDs under 16%, and sensitivity with limits of detection in the order of hundreds picograms per gram of sample (between 0.2 and 0.7ng/g). This method was also applied to the analysis of six microwave popcorn bags and the popcorn inside before and after cooking. PFCAs contents between 3.50ng/g and 750ng/g were found in bags, being PFHxA (perfluorohexanoic acid) the most abundant of them. However, no PFAAs were detected either corn or popcorn, therefore no migration was assumed.

  20. Determination of perfluorinated alkyl acids in corn, popcorn and popcorn bags before and after cooking by focused ultrasound solid-liquid extraction, liquid chromatography and quadrupole-time of flight mass spectrometry.

    PubMed

    Moreta, Cristina; Tena, María Teresa

    2014-08-15

    An analytical method is proposed to determine ten perfluorinated alkyl acids (PFAAs) [nine perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS)] in corn, popcorn and microwave popcorn packaging by focused ultrasound solid-liquid extraction (FUSLE) and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-time of flight mass spectrometry (QTOF-MS/MS). Selected PFAAs were extracted efficiently in only one 10-s cycle by FUSLE, a simple, safe and inexpensive technique. The developed method was validated for microwave popcorn bags matrix as well as corn and popcorn matrices in terms of linearity, matrix effect error, detection and quantification limits, repeatability and recovery values. The method showed good accuracy with recovery values around 100% except for the lowest chain length PFAAs, satisfactory reproducibility with RSDs under 16%, and sensitivity with limits of detection in the order of hundreds picograms per gram of sample (between 0.2 and 0.7ng/g). This method was also applied to the analysis of six microwave popcorn bags and the popcorn inside before and after cooking. PFCAs contents between 3.50ng/g and 750ng/g were found in bags, being PFHxA (perfluorohexanoic acid) the most abundant of them. However, no PFAAs were detected either corn or popcorn, therefore no migration was assumed. PMID:24986069

  1. Aquatic risk assessment of a polycarboxylate dispersant polymer used in laundry detergents.

    PubMed

    Hamilton, J D; Freeman, M B; Reinert, K H

    1996-09-01

    Polycarboxylates enhance detergent soil removal properties and prevent encrustation of calcium salts on fabrics during washing. Laundry wastewater typically reaches wastewater treatment plants, which then discharge into aquatic environments. The yearly average concentration of a 4500 molecular weight (MW) sodium acrylate homopolymer reaching U.S. wastewater treatment plants will be approximately 0.7 mg/L. Publications showing the low to moderate acute aquatic toxicity of polycarboxylates are readily available. However, there are no published evaluations that estimate wastewater removal and characterize the probability of exceedance of acceptable chronic aquatic exposure. WW-TREAT can be used to estimate removal during wastewater treatment and PG-GRIDS can be applied to characterize risk for exceedance in wastewater treatment plant outfalls. After adjustments for the MW distribution of the homopolymer, WW-TREAT predicted that 6.5% will be removed in primary treatment plants and 60% will be removed in combined primary and activated sludge treatment plants. These estimates are consistent with wastewater fate tests, but underestimate homopolymer removal when homopolymer precipitation is included. Acceptable levels of chronic outfall (receiving water) exposure were based on aquatic toxicity testing in algae, fish, and Daphnia magna. PG-GRIDS predicted that no unreasonable risk for exceedance of acceptable chronic exposure will occur in the outfalls of U.S. wastewater plants. Future development of wastewater treatment models should consider polymer MW distribution and precipitation as factors that may alter removal of materials from wastewater.

  2. Capillary electrochromatography with polyacrylamide monolithic stationary phases having bonded dodecyl ligands and sulfonic acid groups: evaluation of column performance with alkyl phenyl ketones and neutral moderately polar pesticides.

    PubMed

    Zhang, M; El Rassi, Z

    2001-08-01

    In this report, we describe the preparation of porous polyacrylamide-based monolithic columns via vinyl polymerization. These monoliths possess in their structures bonded dodecyl ligands and sulfonic acid groups. While the sulfonic acid groups are meant to support the electroosmotic flow (EOF) necessary for moving the mobile phase through the monolithic capillary, the dodecyl ligands are introduced to provide the nonpolar sites for chromatographic retention. However, incorporating the sulfonic acid groups in the monoliths does not only support the EOF but also exhibit hydrophilic interaction with moderately polar compounds such as urea herbicides and carbamates insecticides. Consequently, mixed-mode (reversed-phase/normal phase) retention behavior is observed with neutral and moderately polar pesticides. The amount of sulfonic acid group in the monolith can be conveniently adjusted by changing the amount of vinylsulfonic acid added to the polymerization reaction. Optimum EOF velocity and adequate chromatographic retention are obtained when 15% vinylsulfonic acid is added to the reaction mixture. Under these conditions, rapid separation and high plate counts reaching greater than 400000 plates/m are readily obtained.

  3. [Acidites et complexes des acides (alkyl-et aminoalkyl-) phosphoniques--III Alkylphosphonates substitues de calcium(II) et cuivre(II)].

    PubMed

    Wozniak, M; Nowogrocki, G

    1979-05-01

    The stability constants of some phosphoric acids RPO(3)H(2) [R = CH(3), C(2)H(5), ClCH(2), Cl(2)CH, Cl(3)C, BrCH(2), Br(2)CH, BrCH(2)CH(2), ICH(2), HOCH(2), (CH(3))(3)N + CH2] and their complexes RPO(3)Ca, RPO(3)Cu, RPO(3)Cu(OH)(-) have been determined by multiparametric refinement of potentiometric titration data obtained at 25 degrees , in a 0.1M potassium nitrate medium. Linear relationships are obtained between stability and acidity constants. Formation of five-membered rings stabilize the hydroxymethylphosphonates. Conversely, cation repulsion by the permanent positive charge reduces the stabilities of complexes with trimethylammoniummethylphosphonic acid. PMID:18962453

  4. [Acidites et complexes des acides (alkyl-et aminoalkyl-) phosphoniques--III Alkylphosphonates substitues de calcium(II) et cuivre(II)].

    PubMed

    Wozniak, M; Nowogrocki, G

    1979-05-01

    The stability constants of some phosphoric acids RPO(3)H(2) [R = CH(3), C(2)H(5), ClCH(2), Cl(2)CH, Cl(3)C, BrCH(2), Br(2)CH, BrCH(2)CH(2), ICH(2), HOCH(2), (CH(3))(3)N + CH2] and their complexes RPO(3)Ca, RPO(3)Cu, RPO(3)Cu(OH)(-) have been determined by multiparametric refinement of potentiometric titration data obtained at 25 degrees , in a 0.1M potassium nitrate medium. Linear relationships are obtained between stability and acidity constants. Formation of five-membered rings stabilize the hydroxymethylphosphonates. Conversely, cation repulsion by the permanent positive charge reduces the stabilities of complexes with trimethylammoniummethylphosphonic acid.

  5. N-alkyl-4-boronopyridinium salts as thermally stable and reusable amide condensation catalysts.

    PubMed

    Maki, Toshikatsu; Ishihara, Kazuaki; Yamamoto, Hisashi

    2005-10-27

    [reaction: see text] N-Alkyl-4-boronopyridinium salts are highly effective and reusable catalysts for the dehydrative amide condensation reaction between equimolar mixtures of carboxylic acids and amines. N-Alkylboronopyridinium salts are thermally stabilized in the order N-alkyl-2-boronopyridinium salt < N-alkyl-3-boronopyridinium salt < N-alkyl-4-boronopyridinium salt. Homogeneous catalysts, such as 4-borono-N-methylpyridinium iodide, are more effective in the presence of ionic liquid and can be recovered by extraction with ionic liquid. In contrast, heterogeneous catalysts, such as polystyrene-bound 4-boronopyridinium salts, are effective even in the absence of ionic liquid and can be recovered by filtration.

  6. Identification and biological activity of 6-alkyl-substituted 3-methyl-pyridine-2-carbonyl amino dimethyl-benzoic acid EP4 antagonists.

    PubMed

    Blanco, Maria-Jesus; Vetman, Tatiana; Chandrasekhar, Srinivasan; Fisher, Matthew J; Harvey, Anita; Kuklish, Steven L; Chambers, Mark; Lin, Chaohua; Mudra, Daniel; Oskins, Jennifer; Wang, Xu-Shan; Yu, Xiao-Peng; Warshawsky, Alan M

    2016-05-01

    Continued SAR optimization of a series of 3-methylpyridine-2-carbonyl amino-2,4-dimethyl-benzoic acid led to the selection of compound 4f for clinical studies. Compound 4f showed an IC50 of 123nM for inhibition of PGE2-induced TNFα reduction in an ex vivo LPS-stimulated human whole blood assay (showing >10-fold increase over clinical compound CJ-023,423). Pharmacokinetic profile, selectivity and in vivo efficacy comparing 4f to NSAID diclofenac in the monoiodoacetic acid (MIA) pain model and adjuvant induced arthritis (AIA) inflammatory model are included.

  7. Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration.

    PubMed

    Mari, Michele; Lucarini, Simone; Bartoccini, Francesca; Piersanti, Giovanni; Spadoni, Gilberto

    2014-01-01

    The reaction of 3-substituted indoles with dehydroalanine (Dha) derivatives under Lewis acid-mediated conditions has been investigated. The formation of 2-substituted tryptophans is proposed to occur through a selective alkylative dearomatization-cyclization followed by C3- to C2-alkyl migration and rearomatization. PMID:25246958

  8. One-Pot Synthesis of α-Amino Acids through Carboxylation of Ammonium Ylides with CO2 Followed by Alkyl Migration.

    PubMed

    Mita, Tsuyoshi; Sugawara, Masumi; Sato, Yoshihiro

    2016-06-17

    A simple, yet powerful protocol for α-amino acid synthesis using carbon dioxide (CO2) was developed. α-Amino silanes could undergo four successive reactions (formation of ammonium salt, carboxylation, esterification, and 2,3- or 1,2-Stevens rearrangement) in the presence of allylic or benzylic halides under a CO2 atmosphere (1 atm). It is noteworthy that carboxylation at the position adjacent to a nitrogen atom proceeded via an ammonium ylide intermediate under mild conditions. PMID:27223669

  9. Mild Catalytic methods for Alkyl-Alkyl Bond Formation

    SciTech Connect

    Vicic, David A

    2009-08-10

    Overview of Research Goals and Accomplishments for the Period 07/01/06 – 06/30/07: Our overall research goal is to transform the rapidly emerging synthetic chemistry involving alkyl-alkyl cross-couplings into more of a mechanism-based field so that that new, rationally-designed catalysts can be performed under energy efficient conditions. Our specific objectives for the previous year were 1) to obtain a proper electronic description of an active catalyst for alkyl-alkyl cross-coupling reactions and 2) to determine the effect of ligand structure on the rate, scope, selectivity, and functional group compatibility of C(sp3)-C(sp3) cross-coupling catalysis. We have completed both of these initial objectives and established a firm base for further studies. The specific significant achievements of the current grant period include: 1) we have performed magnetic and computational studies on (terpyridine)NiMe, an active catalyst for alkyl-alkyl cross couplings, and have discovered that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand; 2) we have for the first time shown that alkyl halide reduction by terpyridyl nickel catalysts is substantially ligand based; 3) we have shown by isotopic labeling studies that the active catalyst (terpyridine)NiMe is not produced via a mechanism that involves the formation of methyl radicals when (TMEDA)NiMe2 is used as the catalyst precursor; 4) we have performed an extensive ligand survey for the alkyl-alkyl cross-coupling reactions and have found that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors; 5) we have found that the use of bis(dialkylphosphino)methanes as ligands for nickel does not produce active catalysts for cross-coupling but rather leads to bridging hydride

  10. Maxima in antioxidant distributions and efficiencies with increasing hydrophobicity of gallic acid and its alkyl esters. The pseudophase model interpretation of the "cutoff effect".

    PubMed

    Losada Barreiro, Sonia; Bravo-Díaz, Carlos; Paiva-Martins, Fátima; Romsted, Laurence S

    2013-07-01

    Antioxidant (AO) efficiencies are reported to go through maxima with increasing chain length (hydrophobicity) in emulsions. The so-called "cutoff" after the maxima, indicating a decrease in efficiency, remains unexplained. This paper shows, for gallic acid (GA) and propyl, octyl, and lauryl gallates (PG, OG, and LG, respectively), that at any given volume fraction of emulsifier, the concentrations of antioxidants in the interfacial region of stripped corn oil emulsions and their efficiency order follow PG > GA > OG > LG. These results provide clear evidence that an AO's efficiency correlates with its fraction in the interfacial region. AO distributions were obtained in intact emulsions by using the pseudophase kinetic model to interpret changes in observed rate constants of the AOs with a chemical probe, and their efficiencies were measured by employing the Schaal oven test. The model provides a natural explanation for the maxima with increasing AO hydrophobicity.

  11. Novel halogenated 3-deazapurine, 7-deazapurine and alkylated 9-deazapurine derivatives of L-ascorbic or imino-L-ascorbic acid: Synthesis, antitumour and antiviral activity evaluations.

    PubMed

    Stipković Babić, Maja; Makuc, Damjan; Plavec, Janez; Martinović, Tamara; Kraljević Pavelić, Sandra; Pavelić, Krešimir; Snoeck, Robert; Andrei, Graciela; Schols, Dominique; Wittine, Karlo; Mintas, Mladen

    2015-09-18

    Keeping the potential synergy of biological activity of synthetic anomalous derivatives of deazapurines and l-ascorbic acid (l-AA) in mind, we have synthesized new 3-, 7- and 9-deazapurine derivatives of l-ascorbic (1-4, 8-10, 13-15) and imino-l-ascorbic acid (5-7, 11, 12, 16-19). These novel compounds were evaluated for their cytostatic and antiviral activity in vitro against a panel of human malignant tumour cell lines and normal murine fibroblasts (3T3). Among all evaluated compounds, the 9-deazapurine derivative of l-AA (13) exerted the most potent inhibitory activity on the growth of CEM/0 cells (IC50 = 4.1 ± 1.8 μM) and strong antiproliferative effect against L1210/0 (IC50 = 4.7 ± 0.1 μM) while the 9-deazahypoxanthine derivative of l-AA (15) showed the best effect against HeLa cells (IC50 = 5.6 ± 1.3 μM) and prominent effect on L1210/0 (IC50 = 4.5 ± 0.5 μM). Furthermore, the 9-deazapurine derivative disubstituted with two imino-l-AA moieties (18) showed the best activity against L1210/0 tumour cells (IC50 = 4.4 ± 0.3 μM) and the most pronounced antiproliferative effects against MiaPaCa-2 cells (IC50 = 5.7 ± 0.2 μM). All these compounds showed selective cytostatic effect on tumour cell lines in comparison with embryonal murine fibroblasts (3T3). When evaluating their antiviral activity, the 3-deazapurine derivative of l-AA (3) exhibited the highest activity against both laboratory-adapted strains of human cytomegalovirus (HCMV) (AD-169 and Davis) with EC50 values comparable to those of the well-known anti-HCMV drug ganciclovir and without cytotoxic effects on normal human embryonal lung (HEL) cells.

  12. PROCESS OF RECOVERING ZIRCONIUM VALUES FROM HAFNIUM VALUES BY SOLVENT EXTRACTION WITH AN ALKYL PHOSPHATE

    DOEpatents

    Peppard, D.F.

    1960-02-01

    A process of separating hafnium nitrate from zirconium nitrate contained in a nitric acid solution by selectively. extracting the zirconium nitrate with a water-immiscible alkyl phosphate is reported.

  13. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  14. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  15. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  16. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  17. Radioiodination of Aryl-Alkyl Cyclic Sulfates

    PubMed Central

    Mushti, Chandra; Papisov, Mikhail I.

    2015-01-01

    Among the currently available positron emitters suitable for Positron Emission Tomography (PET), 124I has the longest physical half-life (4.2 days). The long half-life and well-investigated behavior of iodine in vivo makes 124I very attractive for pharmacological studies. In this communication, we describe a simple yet effective method for the synthesis of novel 124I labeled compounds intended for PET imaging of arylsulfatase activity in vivo. Arylsulfatases have important biological functions, and genetic deficiencies of such functions require pharmacological replacement, the efficacy of which must be properly and non-invasively evaluated. These enzymes, even though their natural substrates are mostly of aliphatic nature, hydrolyze phenolic sulfates to phenol and sulfuric acid. The availability of [124I]iodinated substrates is expected to provide a PET-based method for measuring their activity in vivo. The currently available methods of synthesis of iodinated arylsulfates usually require either introducing of a protected sulfate ester early in the synthesis or introduction of sulfate group at the end of synthesis in a separate step. The described method gives the desired product in one step from an aryl-alkyl cyclic sulfate. When treated with iodide, the source cyclic sulfate opens with substitution of iodide at the alkyl center and gives the desired arylsulfate monoester. PMID:23135631

  18. Oil compositions containing alkyl amine or alkyl mercaptan derivatives of copolymers of an alpha olefin or an alkyl vinyl ether

    SciTech Connect

    Le, H.T.

    1990-02-13

    This patent describes an oil composition. It comprises a major amount of an oil selected from a crude oil or fuel oil and a minor amount of an alkyl amine or alkyl mercaptan derivative of an alpha olefin or alkyl vinyl ether and an unsaturated alpha, beta-dicarboxylic compound copolymer having pour point depressant ;properties. The copolymer comprising the reaction product of an alpha olefin having from about 2 to about 30 carbon atoms or mixtures of alpha olefins having from about 2 to about 30 carbon atoms or an alkyl vinyl ether or mixture of alkyl vinyl ethers.

  19. Synthesis, crystal structure and photoluminescence property of Eu/Tb MOFs with mixed polycarboxylate ligands

    NASA Astrophysics Data System (ADS)

    Yang, Lu; Zhang, Sheng; Qu, Xiaoni; Yang, Qi; Liu, Xiangyu; Wei, Qing; Xie, Gang; Chen, Sanping

    2015-11-01

    Lanthanide MOFs, [Eu(TCA)(NDC)·H2O]n (1) and [Tb(TCA)(NDC)·H2O]n (2), have been prepared with the mixed aromatic carboxylate ligands, namely, 4,4‧,4″-tricarboxytriphenylamine (H3TCA) and 1,4-naphthalenedicarboxylate (H2NDC). Single-crystal X-ray diffraction analysis reveals that isomorphic 1 and 2 present pillar-layered 3D framework that Eu/Tb(III) bond with carboxylate in various coordination fashions. Optical investigation indicates that the as-prepared compounds feature characteristic luminescence emission bands of Eu/Tb ions in the visible regions at room temperature. Moreover, compound 2 shows a relatively longer luminescence lifetime (τ=0.342 ms) and significantly enhanced quantum yield (Φoverall=11%) comparing with those of 1 (τ=0.335 ms, Φoverall=0.06%). Two Ln-MOFs (Ln=EuIII, TbIII) with mixed polycarboxylate ligands present different luminescent properties.

  20. Comparing Cyclophellitol N-Alkyl and N-Acyl Cyclophellitol Aziridines as Activity-Based Glycosidase Probes.

    PubMed

    Jiang, Jianbing; Beenakker, Thomas J M; Kallemeijn, Wouter W; van der Marel, Gijsbert A; van den Elst, Hans; Codée, Jeroen D C; Aerts, Johannes M F G; Overkleeft, Herman S

    2015-07-20

    The synthesis and evaluation as activity-based probes (ABPs) of three configurationally distinct, fluorescent N-alkyl cyclophellitol aziridine isosteres for profiling GH1 β-glucosidase (GBA), GH27 α-galactosidase (GLA) and GH29 α-fucosidase (FUCA) is described. In comparison with the corresponding acyl aziridine ABPs reported previously, the alkyl aziridine ABPs are synthesized easily and are more stable in mild acidic and basic media, and are thus easier to handle. The β-glucose-configured alkyl aziridine ABP proves equally effective in labeling GBA as its N-acyl counterpart, whereas the N-acyl aziridines targeting GLA and FUCA outperform their N-alkyl counterparts. Alkyl aziridines can therefore be an attractive alternative in retaining glycosidase ABP design, but in targeting a new retaining glycosidase both N-alkyl and N-acyl aziridines are best considered at the onset of a new study.

  1. Quantification of lipid alkyl radicals trapped with nitroxyl radical via HPLC with postcolumn thermal decomposition.

    PubMed

    Koshiishi, Ichiro; Tsuchida, Kazunori; Takajo, Tokuko; Komatsu, Makiko

    2005-11-01

    Lipid alkyl radicals generated from polyunsaturated fatty acids via chemical or enzymatic H-abstraction have been a pathologically important target to quantify. In the present study, we established a novel method for the quantification of lipid alkyl radicals via nitroxyl radical spin-trapping. These labile lipid alkyl radicals were converted into nitroxyl radical-lipid alkyl radical adducts using 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrroline-N-oxyl (CmdeltaP) (a partition coefficient between octanol and water is approximately 3) as a spin-trapping agent. The resulting CmdeltaP-lipid alkyl radical adducts were determined by HPLC with postcolumn online thermal decomposition, in which the adducts were degraded into nitroxyl radicals by heating at 100 degrees C for 2 min. The resulting nitroxyl radicals were selectively and sensitively detected by electrochemical detection. With the present method, we, for the first time, determined the lipid alkyl radicals generated from linoleic acid, linolenic acid, and arachidonic acid via soybean lipoxygenase-1 or the radical initiator 2,2'-azobis(2,4-dimethyl-valeronitrile).

  2. Alkyl and phenolic glycosides from Saussurea stella.

    PubMed

    Wang, Tian-Min; Wang, Ru-Feng; Chen, Hu-Biao; Shang, Ming-Ying; Cai, Shao-Qing

    2013-07-01

    One alkyl glycoside, saussurostelloside A (1), two phenolic glycosides, saussurostellosides B1 (2) and B2 (3), and 27 known compounds, including eleven flavonoids, seven phenolics, six lignans, one neolignan, one phenethyl glucoside and one fatty acid, were isolated from an ethanol extract of Saussurea stella (Asteraceae). Their structures were elucidated by NMR, MS, UV, and IR spectroscopic analysis. Of the known compounds, (+)-medioresinol-di-O-β-D-glucoside (7), picraquassioside C (10), and diosmetin-3'-O-β-D-glucoside (27) were isolated from the Asteraceae family for the first time, while (+)-pinoresinol-di-O-β-D-glucoside (6), di-O-methylcrenatin (11), protocatechuic acid (14), 1,5-di-O-caffeoylquinic acid (17), formononetin (28), and phenethyl glucoside (29) were isolated from the Saussurea genus for the first time. The anti-inflammatory activities of three new compounds (1-3), five lignans ((-)-arctiin (4), (+)-pinoresinol-4-O-β-D-glucoside (5), (+)-pinoresinol-di-O-β-D-glucoside (6), (+)-medioresinol-di-O-β-D-glucoside (7) and (+)-syringaresinol-4-O-β-D-glucoside (8)), one neolignan (picraquassioside C (10)), and one phenolic glycoside (di-O-methylcrenatin (11)) were evaluated by testing their inhibition of the release of β-glucuronidase from PAF-stimulated neutrophils. Only compound 5 showed moderate inhibition of the release of β-glucuronidase, with an inhibition ratio of 39.1%.

  3. Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl-alkyl Kumada coupling reactions.

    PubMed

    Breitenfeld, Jan; Ruiz, Jesus; Wodrich, Matthew D; Hu, Xile

    2013-08-14

    Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the oxidative addition of alkyl halide. The catalysis is second-order in Grignard reagent, first-order in catalyst, and zero-order in alkyl halide. A transient species, [(N2N)Ni-alkyl(2)](alkyl(2)-MgCl), is identified as the key intermediate responsible for the activation of alkyl halide, the formation of which is the turnover-determining step of the catalysis.

  4. Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl-alkyl Kumada coupling reactions.

    PubMed

    Breitenfeld, Jan; Ruiz, Jesus; Wodrich, Matthew D; Hu, Xile

    2013-08-14

    Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the oxidative addition of alkyl halide. The catalysis is second-order in Grignard reagent, first-order in catalyst, and zero-order in alkyl halide. A transient species, [(N2N)Ni-alkyl(2)](alkyl(2)-MgCl), is identified as the key intermediate responsible for the activation of alkyl halide, the formation of which is the turnover-determining step of the catalysis. PMID:23865460

  5. Alkyl Caffeates Improve the Antioxidant Activity, Antitumor Property and Oxidation Stability of Edible Oil

    PubMed Central

    Wang, Jun; Gu, Shuang-Shuang; Pang, Na; Wang, Fang-Qin; Pang, Fei; Cui, Hong-Sheng; Wu, Xiang-Yang; Wu, Fu-An

    2014-01-01

    Caffeic acid (CA) is distributed widely in nature and possesses strong antioxidant activity. However, CA has lower solubility in non-polar media, which limits its application in fat-soluble food. To increase the lipophilicity of natural antioxidant CA, a series of alkyl caffeates were synthesized and their antioxidant and antitumor activities were investigated. The antioxidant parameters, including the induction period, acid value and unsaturated fatty acid content, of the alkyl caffeates in edible oil were firstly investigated. The results indicated that alkyl caffeates had a lower DPPH IC50 (14–23 µM) compared to CA, dibutyl hydroxy toluene (BHT) and Vitamin C (24–51 µM), and significantly inhibited four human cancer cells (SW620, SW480, SGC7901 and HepG2) with inhibition ratio of 71.4–78.0% by a MTT assay. With regard to the induction period and acid value assays, methyl and butyl caffeates had higher abilities than BHT to restrain the oxidation process and improve the stability of edible oil. The addition of ethyl caffeate to oil allowed maintenance of a higher unsaturated fatty acid methyl ester content (68.53%) at high temperatures. Overall, the alkyl caffeats with short chain length (n<5) assessed better oxidative stability than those with long chain length. To date, this is the first report to the correlations among the antioxidant activity, anticancer activity and oxidative stability of alkyl caffeates. PMID:24760050

  6. Alkyl caffeates improve the antioxidant activity, antitumor property and oxidation stability of edible oil.

    PubMed

    Wang, Jun; Gu, Shuang-Shuang; Pang, Na; Wang, Fang-Qin; Pang, Fei; Cui, Hong-Sheng; Wu, Xiang-Yang; Wu, Fu-An

    2014-01-01

    Caffeic acid (CA) is distributed widely in nature and possesses strong antioxidant activity. However, CA has lower solubility in non-polar media, which limits its application in fat-soluble food. To increase the lipophilicity of natural antioxidant CA, a series of alkyl caffeates were synthesized and their antioxidant and antitumor activities were investigated. The antioxidant parameters, including the induction period, acid value and unsaturated fatty acid content, of the alkyl caffeates in edible oil were firstly investigated. The results indicated that alkyl caffeates had a lower DPPH IC₅₀ (14-23 µM) compared to CA, dibutyl hydroxy toluene (BHT) and Vitamin C (24-51 µM), and significantly inhibited four human cancer cells (SW620, SW480, SGC7901 and HepG2) with inhibition ratio of 71.4-78.0% by a MTT assay. With regard to the induction period and acid value assays, methyl and butyl caffeates had higher abilities than BHT to restrain the oxidation process and improve the stability of edible oil. The addition of ethyl caffeate to oil allowed maintenance of a higher unsaturated fatty acid methyl ester content (68.53%) at high temperatures. Overall, the alkyl caffeats with short chain length (n<5) assessed better oxidative stability than those with long chain length. To date, this is the first report to the correlations among the antioxidant activity, anticancer activity and oxidative stability of alkyl caffeates. PMID:24760050

  7. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  8. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  9. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  10. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  11. 40 CFR 721.8673 - [(Disubstituted phenyl)]azo dihydro hydroxy alkyl oxo alkyl-substituted-pyridines (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false azo dihydro hydroxy alkyl oxo alkyl... Significant New Uses for Specific Chemical Substances § 721.8673 azo dihydro hydroxy alkyl oxo alkyl...) The chemical substances identified generically as azo dihydro hydroxy alkyl oxo...

  12. Tetrabutylammonium alkyl carboxylate surfactants in aqueous solution: self-association behavior, solution nanostructure, and comparison with tetrabutylammonium alkyl sulfate surfactants.

    PubMed

    Zana, Raoul; Schmidt, Judith; Talmon, Yeshayahu

    2005-12-01

    A series of long and ultralong chain tetrabutylammonium alkyl carboxylate (TBACm, TBA = tetrabutylammonium ion; Cm = carboxylate ion C(m-1)H(2)(m-1)CO(2)(-) of total carbon number m) surfactants have been obtained by direct neutralization of the fatty acids with m = 12, 14, 18, 22, and 24 by tetrabutylammonium hydroxide. Time-resolved fluorescence quenching has been used to determine the micelle aggregation number (N) of the surfactants with m = 12, 14, and 18 in the temperature range 10-50 degrees C and of the surfactants with m = 22 and 24 in the temperature range 25-60 degrees C. In all instances the values of N were well below those that can be calculated for the maximum spherical micelle formed by surfactants with the same alkyl chain as the investigated surfactants on the basis of the oil drop model for the micelle core. The microstructure of selected solutions of TBAC22 was examined using transmission electron microscopy at cryogenic temperature and compared to the microstructure of solutions of TBA dodecyl and tetradecyl sulfates. These observations generally confirmed the findings of TRFQ. The self-association behavior of these anionic surfactants with TBA counterions is explained on the basis of the large size and the hydrophobicity of the tetrabutylammonium ions. The important differences in behavior that have been evidenced between tetrabutylammonium alkyl carboxylates and alkyl sulfates are discussed in terms of differences in distribution of the surfactant electrical charge on the headgroup and alkyl chain predicted by quantum chemical calculations (Langmuir 1999, 15, 7546).

  13. The effect of ultrasound on the setting reaction of zinc polycarboxylate cements.

    PubMed

    Shahid, S; Billington, R W; Hill, R G; Pearson, G J

    2010-11-01

    The set of glass ionomer cement (GIC) is accelerated by application of ultrasound. Although GIC has somewhat displaced zinc polycarboxylate cement (ZPC) in dental applications the latter is still extensively used. Like GIC, it provides direct adhesion to tooth and can provide F release, but is more radiopaque and biocompatible than GIC. The aim of this study is to examine the effect of ultrasound on the setting of ZPC using Fourier transform infra red spectroscopy and any interaction with SnF(2) addition. ZPC with and without SnF(2) addition (+/-S) at luting (L) 2:1 P/L ratio and restorative (R) 4:1 P/L ratio consistencies. Ultrasound is applied to the cement using Piezon-Master 400, EMS, Switzerland at 60 s from start of mixing for 15 s. The ratios of absorbance peak height at 1,400 cm(-1) -COO(-) to that at 1,630 cm(-1) -COOH were measured and compared those obtained for the cement not treated with US. These values were taken at the elapsed time at which no further change in spectrum [ratio] was observed at room temperature [10-20 min]. The US results are taken at 2 or 3 min. No US: R/+S (1.09), R/-S (1.2), L/+S (1.07), L/-S (1.04); US: R/+S (1.50), R/-S (1.64), L/+S (1.38), L/-S (1.05). The results show all four ZPC formulations are very sensitive to ultrasound whether with or without SnF(2). Reducing US to 10 s produces lower initial ratios but these increase up to 10 min when very high ratios (>2) are obtained. Previous studies with restorative GICs found that 40-55 s US was needed to produce the effect found with 15 s on ZPCs. ZPC powder is more basic than GIC glass; this may account for ZPC's greater sensitivity to US. Ultrasound may provide a useful adjunct to the clinical use of ZPC both as luting agent and temporary restorative.

  14. Synthesis and Antioxidant Activity of Alkyl Nitroderivatives of Hydroxytyrosol.

    PubMed

    Gallardo, Elena; Palma-Valdés, Rocío; Sarriá, Beatriz; Gallardo, Irene; de la Cruz, José P; Bravo, Laura; Mateos, Raquel; Espartero, José L

    2016-01-01

    A series of alkyl nitrohydroxytyrosyl ether derivatives has been synthesized from free hydroxytyrosol (HT), the natural olive oil phenol, in order to increase the assortment of compounds with potential neuroprotective activity in Parkinson's disease. In this work, the antioxidant activity of these novel compounds has been evaluated using Ferric Reducing Antioxidant Power (FRAP), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and Oxygen Radical Scavenging Capacity (ORAC) assays compared to that of nitrohydroxytyrosol (NO₂HT) and free HT. New compounds showed variable antioxidant activity depending on the alkyl side chain length; compounds with short chains (2-4 carbon atoms) maintained or even improved the antioxidant activity compared to NO₂HT and/or HT, whereas those with longer side chains (6-8 carbon atoms) showed lower activity than NO₂HT but higher than HT. PMID:27213306

  15. Mechanistic insights into nickamine-catalyzed alkyl-alkyl cross-coupling reactions.

    PubMed

    Breitenfeld, Jan; Hu, Xile

    2014-01-01

    Within the last decades the transition metal-catalyzed cross-coupling of non-activated alkyl halides has significantly progressed. Within the context of alkyl-alkyl cross-coupling, first row transition metals spanning from iron, over cobalt, nickel, to copper have been successfully applied to catalyze this difficult reaction. The mechanistic understanding of these reactions is still in its infancy. Herein we outline our latest mechanistic studies that explain the efficiency of nickel, in particular nickamine-catalyzed alkyl-alkyl cross-coupling reactions.

  16. Catalytic enantioselective synthesis of naturally occurring butenolides via hetero-allylic alkylation and ring closing metathesis.

    PubMed

    Mao, Bin; Geurts, Koen; Fañanás-Mastral, Martín; van Zijl, Anthoni W; Fletcher, Stephen P; Minnaard, Adriaan J; Feringa, Ben L

    2011-03-01

    An efficient catalytic asymmetric synthesis of chiral γ-butenolides was developed based on the hetero-allylic asymmetric alkylation (h-AAA) in combination with ring closing metathesis (RCM). The synthetic potential of the h-AAA-RCM protocol was illustrated with the facile synthesis of (-)-whiskey lactone, (-)-cognac lactone, (-)-nephrosteranic acid, and (-)-roccellaric acid.

  17. Formation of furan fatty alkyl esters from their bis-epoxide fatty esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reactions of epoxidized alkyl soyate with four different alcohols: ethanol, isopropyl alcohol, 2-ethylhexanol, benzyl alcohol, in the presence of Bronsted acid catalyst, were investigated. Products that were not reported in prior studies of similar reactions were found. These were furan fatty acid a...

  18. Catalytic enantioselective synthesis of naturally occurring butenolides via hetero-allylic alkylation and ring closing metathesis.

    PubMed

    Mao, Bin; Geurts, Koen; Fañanás-Mastral, Martín; van Zijl, Anthoni W; Fletcher, Stephen P; Minnaard, Adriaan J; Feringa, Ben L

    2011-03-01

    An efficient catalytic asymmetric synthesis of chiral γ-butenolides was developed based on the hetero-allylic asymmetric alkylation (h-AAA) in combination with ring closing metathesis (RCM). The synthetic potential of the h-AAA-RCM protocol was illustrated with the facile synthesis of (-)-whiskey lactone, (-)-cognac lactone, (-)-nephrosteranic acid, and (-)-roccellaric acid. PMID:21268603

  19. Occupational asthma due to alkyl cyanoacrylate

    SciTech Connect

    Nakazawa, T. )

    1990-08-01

    A case of bronchial asthma induced by occupational exposure to alkyl cyanoacrylate, an adhesive, occurred in an assembly operation. Provocative exposure testing induced immediate and delayed asthmatic responses. Alkyl cyanoacrylate seemed to act as an allergen or as an irritant, resulting in the development of asthma.

  20. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721.9892 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9892 Alkylated urea. (a) Chemical...

  1. C-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Obora, Yasushi

    2016-04-01

    The development of practical, efficient, and atom-economical methods for the formation of carbon-carbon bonds remains a topic of considerable interest in current synthetic organic chemistry. In this review, we have summarized selected topics from the recent literature with particular emphasis on C-alkylation processes involving hydrogen transfer using alcohols as alkylation reagents. This review includes selected highlights concerning recent progress towards the modification of catalytic systems for the α-alkylation of ketones, nitriles, and esters. Furthermore, we have devoted a significant portion of this review to the methylation of ketones, alcohols, and indoles using methanol. Lastly, we have also documented recent advances in β-alkylation methods involving the dimerization of alcohols (Guerbet reaction), as well as new developments in C-alkylation methods based on sp (3) C-H activation. PMID:27573136

  2. A general alkyl-alkyl cross-coupling enabled by redox-active esters and alkylzinc reagents.

    PubMed

    Qin, Tian; Cornella, Josep; Li, Chao; Malins, Lara R; Edwards, Jacob T; Kawamura, Shuhei; Maxwell, Brad D; Eastgate, Martin D; Baran, Phil S

    2016-05-13

    Alkyl carboxylic acids are ubiquitous in all facets of chemical science, from natural products to polymers, and represent an ideal starting material with which to forge new connections. This study demonstrates how the same activating principles used for decades to make simple C-N (amide) bonds from carboxylic acids with loss of water can be used to make C-C bonds through coupling with dialkylzinc reagents and loss of carbon dioxide. This disconnection strategy benefits from the use of a simple, inexpensive nickel catalyst and exhibits a remarkably broad scope across a range of substrates (>70 examples). PMID:27103669

  3. Radiolysis of aqueous solutions of acetic acid in the presence of Na-montmorillonite

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalez, R.; Negron-Mendoza, A.; Ramos, S.; Ponnamperuma, C.

    1990-01-01

    The gamma-irradiation of 0.8 mol dm-3 aqueous, oxygen-free acetic acid solutions was investigated in the presence or absence of Na-montmorillonite. H2, CH4, CO, CO2, and several polycarboxylic acids were formed in all systems. The primary characteristics observed in the latter system were: (1) Higher yield of the decomposition of acetic acid; (2) Lower yield of the formation of polycarboxylic acids; (3) No effect on the formation of methane; (4) Higher yield of the formation of carbon dioxide; and (5) The reduction of Fe3+ in the octahedral sites of Na-montmorillonite. A possible reaction scheme was proposed to account for the observed changes. The results are important in understanding heterogeneous processes in radiation catalysis and might be significant to prebiotic chemistry.

  4. Peroxisome dependency of alkyl-containing GPI-anchor biosynthesis in the endoplasmic reticulum

    PubMed Central

    Kanzawa, Noriyuki; Maeda, Yusuke; Ogiso, Hideo; Murakami, Yoshiko; Taguchi, Ryo; Kinoshita, Taroh

    2009-01-01

    Glycosylphosphatidylinositol-anchored proteins (GPI-APs) play various roles in cell–cell and cell–environment interactions. GPI is synthesized in the endoplasmic reticulum (ER) from phosphatidylinositol (PI) through step-wise reactions including transfers of monosaccharides and preassembled GPI is transferred en bloc to proteins. Cellular PI contains mostly diacyl glycerol and unsaturated fatty acid in the sn-2 position, whereas mammalian GPI-APs have mainly 1-alkyl-2-acyl PI and almost exclusively stearic acid, a saturated chain, at the sn-2 position. The latter characteristic is the result of fatty acid remodeling occurring in the Golgi, generating GPI-anchors compatible with raft membrane. The former characteristic is the result of diacyl to alkyl-acyl change occurring in the third GPI intermediate, glucosaminyl-inositolacylated-PI (GlcN-acyl-PI). Here we investigated the origin of the sn-1 alkyl-chain in GPI-APs. Using cell lines defective in the peroxisomal alkyl-phospholipid biosynthetic pathway, we demonstrated that generation of alkyl-containing GPI is dependent upon the peroxisomal pathway. We further demonstrated that in cells defective in the peroxisome pathway, the chain composition of the diacyl glycerol moiety in GlcN-acyl-PI is different from those in the first intermediate N-acetylglucosaminyl-PI and cellular PI, indicating that not only diacyl to alkyl-acyl change but also diacyl to diacyl change occurs in GlcN-acyl-PI. We therefore propose a biosynthetic step within GlcN-acyl-PI in which the diacyl glycerol (or diacyl phosphatidic acid) part is replaced by diradyl glycerol (or diradyl phosphatidic acid). These results highlight cooperation of three organelles, the ER, the Golgi, and the peroxisome, in the generation of the lipid portion of GPI-APs. PMID:19815513

  5. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

    PubMed

    Wang, Shu; Robertson, Megan L

    2015-06-10

    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  6. Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    DOEpatents

    Moens, Luc

    2003-06-24

    A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.

  7. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  8. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Alkyl ketene dimers. 176.120 Section 176.120 Food... Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may be safely used as a component of articles..., transporting, or holding food, subject to the provisions of this section. (a) The alkyl ketene dimers...

  9. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  10. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  11. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  12. Methods and Mechanisms for Cross-Electrophile Coupling of Csp2 Halides with Alkyl Electrophiles

    PubMed Central

    2016-01-01

    halides to form diarylmethanes. Arylnickel(II) intermediates can insert carbon monoxide to form acylnickel(II) intermediates that react with alkyl halides to form ketones, demonstrating the connection between the mechanisms of reactions of aryl halides and acid chlorides with alkyl halides. The low reactivity of epoxides with nickel can be overcome by the use of either titanium or iodide cocatalysis to facilitate radical generation and this can also be extended to enantioselective arylation of meso-epoxides. The high reactivity of benzyl bromide with nickel, which leads to the formation of bibenzyl in attempted reactions with bromobenzene, can be overcome by using a benzyl mesylate along with cobalt phthalocyanine cocatalysis to convert the mesylate into an alkyl radical. PMID:26011466

  13. Methods and Mechanisms for Cross-Electrophile Coupling of Csp(2) Halides with Alkyl Electrophiles.

    PubMed

    Weix, Daniel J

    2015-06-16

    diarylmethanes. Arylnickel(II) intermediates can insert carbon monoxide to form acylnickel(II) intermediates that react with alkyl halides to form ketones, demonstrating the connection between the mechanisms of reactions of aryl halides and acid chlorides with alkyl halides. The low reactivity of epoxides with nickel can be overcome by the use of either titanium or iodide cocatalysis to facilitate radical generation and this can also be extended to enantioselective arylation of meso-epoxides. The high reactivity of benzyl bromide with nickel, which leads to the formation of bibenzyl in attempted reactions with bromobenzene, can be overcome by using a benzyl mesylate along with cobalt phthalocyanine cocatalysis to convert the mesylate into an alkyl radical.

  14. On-line procedures for alkylation of cysteine residues with 3-bromopropylamine prior to protein sequence analysis.

    PubMed

    Jue, R A; Hale, J E

    1994-09-01

    We have previously shown that 3-bromopropylamine offers several advantages over other alkylating reagents in the modification and subsequent identification of cysteine residues by protein sequencing. We describe here simple on-sequencer procedures for alkylating cysteines in proteins which employ the reduction of cystines in proteins with tri-n-butylphosphine and concomitant alkylation of the resulting cysteines with 3-bromopropylamine. Addition of an aqueous acetone wash to a modified reaction cycle on the Applied Biosystems 477A sequencer removes excess 3-bromopropylamine. As a result, very little background in the first step of the sequence analysis is seen. Under these conditions, cysteines are readily modified and identified during sequencing. Moreover, very little preview of the next amino acid is observed, which indicates that the N-terminal amino acid is not appreciably alkylated by 3-bromopropylamine. On-sequencer methods have been developed for proteins spotted onto glass fiber filters and proteins electroblotted onto polyvinylidene difluoride membranes.

  15. N-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed.

  16. N-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed. PMID:27573267

  17. Safety assessment of Salicylic Acid, Butyloctyl Salicylate, Calcium Salicylate, C12-15 Alkyl Salicylate, Capryloyl Salicylic Acid, Hexyldodecyl Salicylate, Isocetyl Salicylate, Isodecyl Salicylate, Magnesium Salicylate, MEA-Salicylate, Ethylhexyl Salicylate, Potassium Salicylate, Methyl Salicylate, Myristyl Salicylate, Sodium Salicylate, TEA-Salicylate, and Tridecyl Salicylate.

    PubMed

    2003-01-01

    Salicylic Acid is an aromatic acid used in cosmetic formulations as a denaturant, hair-conditioning agent, and skin-conditioning agent--miscellaneous in a wide range of cosmetic products at concentrations ranging from 0.0008% to 3%. The Calcium, Magnesium, and MEA salts are preservatives, and Potassium Salicylate is a cosmetic biocide and preservative, not currently in use. Sodium Salicylate is used as a denaturant and preservative (0.09% to 2%). The TEA salt of Salicylic Acid is used as an ultraviolet (UV) light absorber (0.0001% to 0.75%). Several Salicylic Acid esters are used as skin conditioning agents--miscellaneous (Capryloyl, 0.1% to 1%; C12-15 Alkyl, no current use; Isocetyl, 3% to 5%; Isodecyl, no current use; and Tridecyl, no current use). Butyloctyl Salicylate (0.5% to 5%) and Hexyldodecyl Salicylate (no current use) are hair-conditioning agents and skin-conditioning agents--miscellaneous. Ethylhexyl Salicylate (formerly known as Octyl Salicylate) is used as a fragrance ingredient, sunscreen agent, and UV light absorber (0.001% to 8%), and Methyl Salicylate is used as a denaturant and flavoring agent (0.0001% to 0.6%). Myristyl Salicylate has no reported function. Isodecyl Salicylate is used in three formulations, but no concentration of use information was reported. Salicylates are absorbed percutaneously. Around 10% of applied salicylates can remain in the skin. Salicylic Acid is reported to enhance percutaneous penetration of some agents (e.g., vitamin A), but not others (e.g., hydrocortisone). Little acute toxicity (LD(50) in rats; >2 g/kg) via a dermal exposure route is seen for Salicylic Acid, Methyl Salicylate, Tridecyl Salicylate, and Butyloctyl Salicylate. Short-term oral, inhalation, and parenteral exposures to salicylates sufficient to produce high blood concentrations are associated primarily with liver and kidney damage. Subchronic dermal exposures to undiluted Methyl Salicylate were associated with kidney damage. Chronic oral exposure to

  18. Safety assessment of Salicylic Acid, Butyloctyl Salicylate, Calcium Salicylate, C12-15 Alkyl Salicylate, Capryloyl Salicylic Acid, Hexyldodecyl Salicylate, Isocetyl Salicylate, Isodecyl Salicylate, Magnesium Salicylate, MEA-Salicylate, Ethylhexyl Salicylate, Potassium Salicylate, Methyl Salicylate, Myristyl Salicylate, Sodium Salicylate, TEA-Salicylate, and Tridecyl Salicylate.

    PubMed

    2003-01-01

    Salicylic Acid is an aromatic acid used in cosmetic formulations as a denaturant, hair-conditioning agent, and skin-conditioning agent--miscellaneous in a wide range of cosmetic products at concentrations ranging from 0.0008% to 3%. The Calcium, Magnesium, and MEA salts are preservatives, and Potassium Salicylate is a cosmetic biocide and preservative, not currently in use. Sodium Salicylate is used as a denaturant and preservative (0.09% to 2%). The TEA salt of Salicylic Acid is used as an ultraviolet (UV) light absorber (0.0001% to 0.75%). Several Salicylic Acid esters are used as skin conditioning agents--miscellaneous (Capryloyl, 0.1% to 1%; C12-15 Alkyl, no current use; Isocetyl, 3% to 5%; Isodecyl, no current use; and Tridecyl, no current use). Butyloctyl Salicylate (0.5% to 5%) and Hexyldodecyl Salicylate (no current use) are hair-conditioning agents and skin-conditioning agents--miscellaneous. Ethylhexyl Salicylate (formerly known as Octyl Salicylate) is used as a fragrance ingredient, sunscreen agent, and UV light absorber (0.001% to 8%), and Methyl Salicylate is used as a denaturant and flavoring agent (0.0001% to 0.6%). Myristyl Salicylate has no reported function. Isodecyl Salicylate is used in three formulations, but no concentration of use information was reported. Salicylates are absorbed percutaneously. Around 10% of applied salicylates can remain in the skin. Salicylic Acid is reported to enhance percutaneous penetration of some agents (e.g., vitamin A), but not others (e.g., hydrocortisone). Little acute toxicity (LD(50) in rats; >2 g/kg) via a dermal exposure route is seen for Salicylic Acid, Methyl Salicylate, Tridecyl Salicylate, and Butyloctyl Salicylate. Short-term oral, inhalation, and parenteral exposures to salicylates sufficient to produce high blood concentrations are associated primarily with liver and kidney damage. Subchronic dermal exposures to undiluted Methyl Salicylate were associated with kidney damage. Chronic oral exposure to

  19. Copper-catalyzed reductive cross-coupling of nonactivated alkyl tosylates and mesylates with alkyl and aryl bromides.

    PubMed

    Liu, Jing-Hui; Yang, Chu-Ting; Lu, Xiao-Yu; Zhang, Zhen-Qi; Xu, Ling; Cui, Mian; Lu, Xi; Xiao, Bin; Fu, Yao; Liu, Lei

    2014-11-17

    A copper-catalyzed reductive cross-coupling reaction of nonactivated alkyl tosylates and mesylates with alkyl and aryl bromides was developed. It provides a practical method for efficient and cost-effective construction of aryl-alkyl and alkyl-alkyl CC bonds with stereocontrol from readily available substrates. When used in an intramolecular fashion, the reaction enables convenient access to various substituted carbo- or heterocycles, such as 2,3-dihydrobenzofuran and benzochromene derivatives.

  20. Enantioselective Friedel-Crafts Alkylation Reactions of 3-Substituted Indoles with Electron-Deficient Alkenes.

    PubMed

    Weng, Jian-Quan; Fan, Ren-Jie; Deng, Qiao-Man; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-04-01

    Highly enantioselective Friedel-Crafts C2-alkylation reactions of 3-substituted indoles with α,β-unsaturated esters and nitroalkenes were developed using chiral Lewis acids as catalysts, which afforded chiral indole derivatives bearing C2-benzylic stereogenic centers in good to excellent yields (up to 99%) and enantioselectivities (up to 96% ee). PMID:26959867

  1. Alkyl rearrangement processes in organozirconium complexes. Observation of internal alkyl complexes during hydrozirconation

    SciTech Connect

    Chirik, P.J.; Day, M.W.; Labinger, J.A.; Bercaw, J.E.

    1999-11-10

    Isotopically labeled alkyl zirconocene complexes of the form (CpR{sub n}){sub 2}Zr(CH{sub 2}CDR{sub 2}{prime})(X) (CpR{sub n} = alkyl-substituted cyclopentadienyl; R{prime} = H, alkyl group; X = H, D, Me) undergo isomerization of the alkyl ligand as well as exchange with free olefin in solution under ambient conditions. Increasing the substitution on the Cp ring results in slower isomerization reactions, but these steric effects are small. In contrast, changing X has a very large effect on the rate of isomerization. Pure {sigma}-bonding ligands such as methyl and hydride promote rapid isomerization, whereas {pi}-donor ligands inhibit {beta}-H elimination and hence alkyl isomerization. For ({eta}{sup 5}-C{sub 5}H{sub 5}){sub 2}Zr(R)(Cl), internal alkyl complexes have been observed for the first time. The rate of isomerization depends on the length of the alkyl group: longer alkyl chains (heptyl, hexyl) isomerize faster than shorter chains (butyl). The transient intermediate species have been identified by a combination of isotopic labeling and {sup 1}H, {sup 2}H, and {sup 13}C NMR experiments. The solid-state structure of the zirconocene cyclopentyl chloride complex, Cp{sub 2}Zr(cyclo-C{sub 5}H{sub 9})(Cl), has been determined by X-ray diffraction.

  2. Palladium-Catalyzed Arylation of Alkyl Sulfenate Anions.

    PubMed

    Jia, Tiezheng; Zhang, Mengnan; Jiang, Hui; Wang, Carol Y; Walsh, Patrick J

    2015-11-01

    A unique palladium-catalyzed arylation of alkyl sulfenate anions is introduced that affords aryl alkyl sulfoxides in high yields. Due to the base sensitivity of the starting sulfoxides, sulfenate anion intermediates, and alkyl aryl sulfoxide products, the use of a mild method to generate alkyl sulfenate anions was crucial to the success of this process. Thus, a fluoride triggered elimination strategy was employed with alkyl 2-(trimethylsilyl)ethyl sulfoxides to liberate the requisite alkyl sulfenate anion intermediates. In the presence of palladium catalysts with bulky monodentate phosphines (SPhos and Cy-CarPhos) and aryl bromides or chlorides, alkyl sulfenate anions were readily arylated. Moreover, the thermal fragmentation and the base promoted elimination of alkyl sulfoxides was overridden. The alkyl sulfenate anion arylation exhibited excellent chemoselectivity in the presence of functional groups, such as anilines and phenols, which are also known to undergo palladium catalyzed arylation reactions.

  3. Neighbor-directed histidine N (τ)-alkylation: A route to imidazolium-containing phosphopeptide macrocycles.

    PubMed

    Qian, Wen-Jian; Park, Jung-Eun; Grant, Robert; Lai, Christopher C; Kelley, James A; Yaffe, Michael B; Lee, Kyung S; Burke, Terrence R

    2015-11-01

    Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. Interestingly, these cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.

  4. Practical Ni-Catalyzed Aryl–Alkyl Cross-Coupling of Secondary Redox-Active Esters

    PubMed Central

    2016-01-01

    A new transformation is presented that enables chemists to couple simple alkyl carboxylic acids with aryl zinc reagents under Ni-catalysis. The success of this reaction hinges on the unique use of redox-active esters that allow one to employ such derivatives as alkyl halides surrogates. The chemistry exhibits broad substrate scope and features a high degree of practicality. The simple procedure and extremely inexpensive nature of both the substrates and pre-catalyst (NiCl2·6H2O, ca. $9.5/mol) bode well for the immediate widespread adoption of this method. PMID:26835704

  5. Neighbor-directed histidine N(τ) alkylation. A route to imidazolium-containing phosphopeptide macrocycles

    SciTech Connect

    Qian, Wen-Jian; Park, Jung-Eun; Grant, Robert; Lai, Christopher C.; Kelley, James A.; Yaffe, Michael B.; Lee, Kyung S.; Burke, Terrence R.

    2015-07-07

    Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. These cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Furthermore, neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.

  6. Properties of alkyl hydroxycinnamates and effects on Pseudomonas fluorescens.

    PubMed Central

    Baranowski, J D; Nagel, C W

    1983-01-01

    Alkyl esters of six hydroxycinnamic acids, shown to be active antimicrobial agents when tested against Pseudomonas fluorescens, were further investigated for their effects against this organism. There was no statistically significant adaptation by this organism to either of the methyl esters of caffeic, rho-coumaric, cinnamic, or rho-hydroxybenzoic acids. Mixtures of these compounds taken two at a time gave at least additive effects, with some mixtures showing synergism. Preliminary work was also performed to determine the mode of inhibitory action for these compounds. The inhibition of oxygen utilization by the methyl esters correlated well with growth inhibition. Short-term lethality studies showed that none of the alkyl esters or methyl or propyl paraben produced any bacteriocidal effects. Oil-water partition coefficients were determined for these compounds and were shown to have no correlation with growth inhibitions. These all point to a specific mode of action, based in part on cellular energy depletion, rather than the nonspecific membrane-disrupting effects of other phenolic antimicrobial agents. PMID:6401979

  7. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester,...

  8. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester,...

  9. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester,...

  10. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester,...

  11. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester,...

  12. Carbonylation reactions of alkyl iodides through the interplay of carbon radicals and Pd catalysts.

    PubMed

    Sumino, Shuhei; Fusano, Akira; Fukuyama, Takahide; Ryu, Ilhyong

    2014-05-20

    Numerous methods for transition metal catalyzed carbonylation reactions have been established. Examples that start from aryl, vinyl, allyl, and benzyl halides to give the corresponding carboxylic acid derivatives have all been well documented. In contrast, the corresponding alkyl halides often encounter difficulty. This is inherent to the relatively slow oxidative addition step onto the metal center and subsequent β-hydride elimination which causes isomerization of the alkyl metal species. Radical carbonylation reactions can override such problems of reactivity; however, carbonylation coupled to iodine atom transfer (atom transfer carbonylation), though useful, often suffers from a slow iodine atom transfer step that affects the outcome of the reaction. We found that atom transfer carbonylation of primary, secondary, and tertiary alkyl iodides was efficiently accelerated by the addition of a palladium catalyst under light irradiation. Stereochemical studies support a mechanistic pathway based on the synergic interplay of radical and Pd-catalyzed reaction steps which ultimately lead to an acylpalladium species. The radical/Pd-combined reaction system has a wide range of applications, including the synthesis of carboxylic acid esters, lactones, amides, lactams, and unsymmetrical ketones such as alkyl alkynyl and alkyl aryl ketones. The design of unique multicomponent carbonylation reactions involving vicinal C-functionalization of alkenes, double and triple carbonylation reactions, in tandem with radical cyclization reactions, has also been achieved. Thus, the radical/Pd-combined strategy provides a solution to a longstanding problem of reactivity involving the carbonylation of alkyl halides. This novel methodology expands the breadth and utility of carbonylation chemistry over either the original radical carbonylation reactions or metal-catalyzed carbonylation reactions.

  13. Micellar catalysis of the alkylation of mercuric ions by alkyl cobalt(III) complexes.

    PubMed

    Allen, R J; Bunton, C A

    1976-01-01

    Anionic micelles of sodium lauryl sulfate, NaLS, catalyze the monoalkylation of Hg2+ in dilute acid by alkyl aquobis-(dimethyl glyoximato) cobalt (III), RCo(DH)2(H2O) degrees and the related propane derivatives RCo(DOH) DOpn (H2O)+, where R = Me, Et, n-C5H11. Nonionic micelles of Igepal do not catalyze the reaction. In the absence of micelles RCo(DH)2(H2O) degrees is considerably more reactive than RCo(DOH)DOpn(H2O)+, but this higher reactivity is offset in part by its higher basicity. Anionic micelles markedly increase the basicity of RCo(DOH)DOpn(H2O)+ and slightly increase that of RCo(DH)2(H2O) degrees. For reactions of the unprotonated Co(III) complexes the maximum rate enhancements by micelles of NaLS are: R = Me, 19(131); Et, 58 (65); n-C5H11, 46 (32). (The values in parentheses are for RCo(DOH)DOpn(H2O)+.)

  14. Palladium-Catalyzed, Ring-Forming Aromatic C–H Alkylations with Unactivated Alkyl Halides

    PubMed Central

    Venning, Alexander R. O.; Bohan, Patrick T.; Alexanian, Erik J.

    2015-01-01

    A catalytic C–H alkylation using unactivated alkyl halides and a variety of arenes and heteroarenes is described. This ring-forming process is successful with a variety of unactivated primary and secondary alkyl halides, including those with β-hydrogens. In contrast to standard polar or radical cyclizations of aromatic systems, electronic activation of the substrate is not required. The mild, catalytic reaction conditions are highly functional group tolerant and facilitate access to a diverse range of synthetically and medicinally important carbocyclic and heterocyclic systems. PMID:25746442

  15. Auxiliary-assisted palladium-catalyzed arylation and alkylation of sp2 and sp3 carbon-hydrogen bonds.

    PubMed

    Shabashov, Dmitry; Daugulis, Olafs

    2010-03-24

    We have developed a method for auxiliary-directed, palladium-catalyzed beta-arylation and alkylation of sp(3) and sp(2) C-H bonds in carboxylic acid derivatives. The method employs a carboxylic acid 2-methylthioaniline- or 8-aminoquinoline amide substrate, aryl or alkyl iodide coupling partner, palladium acetate catalyst, and an inorganic base. By employing 2-methylthioaniline auxiliary, selective monoarylation of primary sp(3) C-H bonds can be achieved. If arylation of secondary sp(3) C-H bonds is desired, 8-aminoquinoline auxiliary may be used. For alkylation of sp(3) and sp(2) C-H bonds, 8-aminoquinoline auxiliary affords the best results. Some functional group tolerance is observed and amino- and hydroxy-acid derivatives can be functionalized. Preliminary mechanistic studies have been performed. A palladacycle intermediate has been isolated, characterized by X-ray crystallography, and its reactions have been studied.

  16. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  17. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  18. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  19. 40 CFR 721.8700 - Halogenated alkyl pyridine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Halogenated alkyl pyridine. 721.8700... Substances § 721.8700 Halogenated alkyl pyridine. Link to an amendment published at 79 FR 34638, June 18... identified generically as halogenated alkyl pyridine (PMN P-83-237) is subject to reporting under...

  20. 40 CFR 721.9720 - Disubstituted alkyl triazines (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Disubstituted alkyl triazines (generic... Specific Chemical Substances § 721.9720 Disubstituted alkyl triazines (generic name). Link to an amendment... reporting. (1) The chemical substances identified generically as disubstituted alkyl triazines (PMNs...

  1. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  2. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  3. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl amino nitriles (generic). 721... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs...

  4. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl substituted diaromatic... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  5. 40 CFR 721.550 - Alkyl alkenoate, azobis-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl alkenoate, azobis-. 721.550... Substances § 721.550 Alkyl alkenoate, azobis-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl alkenoate, azobis- (PMN P-88-2470)...

  6. 40 CFR 721.550 - Alkyl alkenoate, azobis-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl alkenoate, azobis-. 721.550... Substances § 721.550 Alkyl alkenoate, azobis-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl alkenoate, azobis- (PMN P-88-2470)...

  7. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  8. 40 CFR 721.648 - Alkyl dialkylamino phenylsulfonyl alkenoate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl dialkylamino phenylsulfonyl... Specific Chemical Substances § 721.648 Alkyl dialkylamino phenylsulfonyl alkenoate (generic). (a) Chemical... as alkyl dialkylamino phenylsulfonyl alkenoate (PMN P-00-0816) is subject to reporting under...

  9. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  10. 40 CFR 721.1852 - Di-alkyl borane (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Di-alkyl borane (generic). 721.1852... Substances § 721.1852 Di-alkyl borane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as di-alkyl borane (PMN P-00-1087) is...

  11. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  12. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  13. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  14. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl substituted diaromatic... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  15. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phosphonate...

  16. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl amino nitriles (generic). 721... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs...

  17. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  18. 40 CFR 721.9720 - Disubstituted alkyl triazines (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Disubstituted alkyl triazines (generic... Specific Chemical Substances § 721.9720 Disubstituted alkyl triazines (generic name). (a) Chemical... as disubstituted alkyl triazines (PMNs P-85-932 and P-85-933) are subject to reporting under...

  19. 40 CFR 721.6490 - Alkyl phenyl polyetheramines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phenyl polyetheramines. 721.6490... Substances § 721.6490 Alkyl phenyl polyetheramines. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phenyl...

  20. 40 CFR 721.10669 - Tertiary amine alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tertiary amine alkyl ether (generic... Specific Chemical Substances § 721.10669 Tertiary amine alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-13-78) is subject to reporting under this section for the significant new...

  1. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethoxylated alkyl quaternary ammonium... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  2. 40 CFR 721.10385 - Phenoxy alkyl ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenoxy alkyl ether (generic). 721... Substances § 721.10385 Phenoxy alkyl ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as phenoxy alkyl ether (PMN...

  3. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl substituted diaromatic... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  4. 40 CFR 721.575 - Substituted alkyl halide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted alkyl halide. 721.575... Substances § 721.575 Substituted alkyl halide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted alkyl halide (PMN P-83-1222)...

  5. 40 CFR 721.10385 - Phenoxy alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenoxy alkyl ether (generic). 721... Substances § 721.10385 Phenoxy alkyl ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as phenoxy alkyl ether (PMN...

  6. 40 CFR 721.647 - Alkoxylated alkyl amine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkoxylated alkyl amine (generic). 721... Substances § 721.647 Alkoxylated alkyl amine (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkoxylated alkyl amine...

  7. 40 CFR 721.10697 - Polyfluorinated alkyl polyamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl polyamide... Specific Chemical Substances § 721.10697 Polyfluorinated alkyl polyamide (generic). (a) Chemical substance... polyfluorinated alkyl polyamide (PMN P-11-487) is subject to reporting under this section for the significant...

  8. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  9. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phosphonate...

  10. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  11. 40 CFR 721.3740 - Bisalkylated fatty alkyl amine oxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Bisalkylated fatty alkyl amine oxide... Substances § 721.3740 Bisalkylated fatty alkyl amine oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisalkylated fatty alkyl...

  12. 40 CFR 721.647 - Alkoxylated alkyl amine (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkoxylated alkyl amine (generic). 721... Substances § 721.647 Alkoxylated alkyl amine (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkoxylated alkyl amine...

  13. 40 CFR 721.8700 - Halogenated alkyl pyridine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Halogenated alkyl pyridine. 721.8700... Substances § 721.8700 Halogenated alkyl pyridine. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated alkyl pyridine (PMN P-83-237)...

  14. 40 CFR 721.10701 - Polyfluorinated alkyl amine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl amine (generic... Specific Chemical Substances § 721.10701 Polyfluorinated alkyl amine (generic). (a) Chemical substance and... polyfluorinated alkyl amine (PMN P-11-532) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl substituted diaromatic... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  16. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  17. 40 CFR 721.10385 - Phenoxy alkyl ether (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenoxy alkyl ether (generic). 721... Substances § 721.10385 Phenoxy alkyl ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as phenoxy alkyl ether (PMN...

  18. 40 CFR 721.648 - Alkyl dialkylamino phenylsulfonyl alkenoate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl dialkylamino phenylsulfonyl... Specific Chemical Substances § 721.648 Alkyl dialkylamino phenylsulfonyl alkenoate (generic). (a) Chemical... as alkyl dialkylamino phenylsulfonyl alkenoate (PMN P-00-0816) is subject to reporting under...

  19. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  20. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  1. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  2. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  3. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  4. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethoxylated alkyl quaternary ammonium... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  5. 40 CFR 721.550 - Alkyl alkenoate, azobis-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl alkenoate, azobis-. 721.550... Substances § 721.550 Alkyl alkenoate, azobis-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl alkenoate, azobis- (PMN P-88-2470)...

  6. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  7. 40 CFR 721.648 - Alkyl dialkylamino phenylsulfonyl alkenoate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl dialkylamino phenylsulfonyl... Specific Chemical Substances § 721.648 Alkyl dialkylamino phenylsulfonyl alkenoate (generic). (a) Chemical... as alkyl dialkylamino phenylsulfonyl alkenoate (PMN P-00-0816) is subject to reporting under...

  8. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  9. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phosphonate...

  10. 40 CFR 721.10453 - Polyglycerin alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyglycerin alkyl ether (generic... Specific Chemical Substances § 721.10453 Polyglycerin alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-02-796) is subject to reporting under this section for the significant new...

  11. 40 CFR 721.1852 - Di-alkyl borane (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Di-alkyl borane (generic). 721.1852... Substances § 721.1852 Di-alkyl borane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as di-alkyl borane (PMN P-00-1087) is...

  12. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  13. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  14. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phosphonate...

  15. 40 CFR 721.9720 - Disubstituted alkyl triazines (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Disubstituted alkyl triazines (generic... Specific Chemical Substances § 721.9720 Disubstituted alkyl triazines (generic name). (a) Chemical... as disubstituted alkyl triazines (PMNs P-85-932 and P-85-933) are subject to reporting under...

  16. 40 CFR 721.1852 - Di-alkyl borane (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Di-alkyl borane (generic). 721.1852... Substances § 721.1852 Di-alkyl borane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as di-alkyl borane (PMN P-00-1087) is...

  17. 40 CFR 721.10696 - Polyfluorinated alkyl thiol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl thiol (generic... Specific Chemical Substances § 721.10696 Polyfluorinated alkyl thiol (generic). (a) Chemical substances and... polyfluorinated alkyl thiol (PMNs P-11-483 and P-11-528) are subject to reporting under this section for...

  18. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  19. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  20. 40 CFR 721.1852 - Di-alkyl borane (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Di-alkyl borane (generic). 721.1852... Substances § 721.1852 Di-alkyl borane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as di-alkyl borane (PMN P-00-1087) is...

  1. 40 CFR 721.575 - Substituted alkyl halide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted alkyl halide. 721.575... Substances § 721.575 Substituted alkyl halide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted alkyl halide (PMN P-83-1222)...

  2. 40 CFR 721.648 - Alkyl dialkylamino phenylsulfonyl alkenoate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl dialkylamino phenylsulfonyl... Specific Chemical Substances § 721.648 Alkyl dialkylamino phenylsulfonyl alkenoate (generic). (a) Chemical... as alkyl dialkylamino phenylsulfonyl alkenoate (PMN P-00-0816) is subject to reporting under...

  3. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  4. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  5. 40 CFR 721.10700 - Polyfluorinated alkyl thio polyacrylamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl thio... Specific Chemical Substances § 721.10700 Polyfluorinated alkyl thio polyacrylamide (generic). (a) Chemical... as polyfluorinated alkyl thio polyacrylamide (PMNs P-11-530 and P-11-533) are subject to...

  6. 40 CFR 721.575 - Substituted alkyl halide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted alkyl halide. 721.575... Substances § 721.575 Substituted alkyl halide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted alkyl halide (PMN P-83-1222)...

  7. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  8. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  9. 40 CFR 721.550 - Alkyl alkenoate, azobis-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl alkenoate, azobis-. 721.550... Substances § 721.550 Alkyl alkenoate, azobis-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl alkenoate, azobis- (PMN P-88-2470)...

  10. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  11. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  12. 40 CFR 721.10453 - Polyglycerin alkyl ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyglycerin alkyl ether (generic... Specific Chemical Substances § 721.10453 Polyglycerin alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-02-796) is subject to reporting under this section for the significant new...

  13. 40 CFR 721.10087 - Substituted alkyl phosphine oxide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkyl phosphine oxide... Specific Chemical Substances § 721.10087 Substituted alkyl phosphine oxide (generic). (a) Chemical... as substituted alkyl phosphine oxide (PMN P-06-332) is subject to reporting under this section...

  14. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  15. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  16. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  17. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  18. 40 CFR 721.9720 - Disubstituted alkyl triazines (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Disubstituted alkyl triazines (generic... Specific Chemical Substances § 721.9720 Disubstituted alkyl triazines (generic name). (a) Chemical... as disubstituted alkyl triazines (PMNs P-85-932 and P-85-933) are subject to reporting under...

  19. 40 CFR 721.3740 - Bisalkylated fatty alkyl amine oxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Bisalkylated fatty alkyl amine oxide... Substances § 721.3740 Bisalkylated fatty alkyl amine oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisalkylated fatty alkyl...

  20. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl amino nitriles (generic). 721... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs...

  1. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  2. 40 CFR 721.10692 - Fluorinated alkyl dianiline (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fluorinated alkyl dianiline (generic... Specific Chemical Substances § 721.10692 Fluorinated alkyl dianiline (generic). (a) Chemical substance and... alkyl dianiline (PMN P-13-288) is subject to reporting under this section for the significant new...

  3. 40 CFR 721.3740 - Bisalkylated fatty alkyl amine oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Bisalkylated fatty alkyl amine oxide... Substances § 721.3740 Bisalkylated fatty alkyl amine oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisalkylated fatty alkyl...

  4. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl amino nitriles (generic). 721... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs...

  5. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  6. 40 CFR 721.6490 - Alkyl phenyl polyetheramines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl phenyl polyetheramines. 721.6490... Substances § 721.6490 Alkyl phenyl polyetheramines. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phenyl...

  7. 40 CFR 721.6490 - Alkyl phenyl polyetheramines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl phenyl polyetheramines. 721.6490... Substances § 721.6490 Alkyl phenyl polyetheramines. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phenyl...

  8. 40 CFR 721.648 - Alkyl dialkylamino phenylsulfonyl alkenoate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl dialkylamino phenylsulfonyl... Specific Chemical Substances § 721.648 Alkyl dialkylamino phenylsulfonyl alkenoate (generic). (a) Chemical... as alkyl dialkylamino phenylsulfonyl alkenoate (PMN P-00-0816) is subject to reporting under...

  9. 40 CFR 721.10699 - Polyfluorinated alkyl thio acrylamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl thio acrylamide... Specific Chemical Substances § 721.10699 Polyfluorinated alkyl thio acrylamide (generic). (a) Chemical... as polyfluorinated alkyl thio acrylamide (PMN P-11-529) is subject to reporting under this...

  10. 40 CFR 721.1852 - Di-alkyl borane (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Di-alkyl borane (generic). 721.1852... Substances § 721.1852 Di-alkyl borane (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as di-alkyl borane (PMN P-00-1087) is...

  11. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  12. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethoxylated alkyl quaternary ammonium... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  13. 40 CFR 721.10698 - Polyfluorinated alkyl halide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl halide (generic... Specific Chemical Substances § 721.10698 Polyfluorinated alkyl halide (generic). (a) Chemical substance and... polyfluorinated alkyl halide (PMN P-11-527) is subject to reporting under this section for the significant...

  14. 40 CFR 721.550 - Alkyl alkenoate, azobis-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl alkenoate, azobis-. 721.550... Substances § 721.550 Alkyl alkenoate, azobis-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl alkenoate, azobis- (PMN P-88-2470)...

  15. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  16. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  17. 40 CFR 721.6490 - Alkyl phenyl polyetheramines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl phenyl polyetheramines. 721.6490... Substances § 721.6490 Alkyl phenyl polyetheramines. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl phenyl...

  18. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethoxylated alkyl quaternary ammonium... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  19. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  20. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl amino nitriles (generic). 721... Substances § 721.555 Alkyl amino nitriles (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs...