Sample records for silicic acid esters

  1. Isolation of pure natural linoleic and linolenic acids as their methyl esters by adsorption fractionation on silicic acid

    Microsoft Academic Search

    R. W. Riemenschneider; S. F. Herb; Peter L. Nichols

    1949-01-01

    Summary  An effective procedure is described for fractionating methyl esters of oils rich in linoleic and linolenic acids by adsorption\\u000a on silicic acid columns. Pure methyl linoleate from methyl esters of tobacco seed oil and pure methyl linolenate from methyl\\u000a esters of linseed and perilla oils were isolated by this procedure. These compounds were characterized by the usual physical\\u000a and chemical

  2. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

  3. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

  4. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

  5. 40 CFR 721.3635 - Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Octadecanoic acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4). 721.3635 Section 721...Substances § 721.3635 Octadecanoic acid, ester with 1,2-propanediol,...

  6. Synthesis and Characterization of Silicate Ester Prodrugs and Poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) Block Copolymers for Formulation into Prodrug-Loaded Nanoparticles

    NASA Astrophysics Data System (ADS)

    Wohl, Adam Richard

    Fine control of the physical and chemical properties of customized materials is a field that is rapidly advancing. This is especially critical in pursuits to develop and optimize novel nanoparticle drug delivery. Specifically, I aim to apply chemistry concepts to test the hypothesis "Silicate ester prodrugs of paclitaxel, customized to have the proper hydrophobicity and hydrolytic lability, can be formulated with well-defined, biocompatible, amphiphilic block copolymers into nanoparticles that are effective drugs." Chapter 1 briefly describes the context and motivation of the scientific pursuits described in this thesis. In Chapter 2, a family of model silicate esters is synthesized, the hydrolysis rate of each compound is benchmarked, and trends are established based upon the steric bulk and leaving group ability of the silicate substituents. These trends are then applied to the synthesis of labile silicate ester prodrugs in Chapter 3. The bulk of this chapter focuses on the synthesis, hydrolysis, and cytotoxicity of prodrugs based on paclitaxel, a widely used chemotherapeutic agent. In Chapter 4, a new methodology for the synthesis of narrowly dispersed, "random" poly(lactic-co-glycolic acid) polymers by a constant infusion of the glycolide monomer is detailed. Using poly(ethylene glycol) as a macroinitiator, amphiphilic block copolymers were synthesized. Co-formulating a paclitaxel silicate and an amphiphilic block copolymer via flash nanoprecipitation led to highly prodrug-loaded, kinetically trapped nanoparticles. Studies to determine the structure, morphology, behavior, and efficacy of these nanoparticles are described in Chapter 5. Efforts to develop a general strategy for the selective end-functionalization of the polyether block of these amphiphilic block copolymers are discussed in Chapter 6. Examples of this strategy include functionalization of the polyether with an azide or a maleimide. Finally, Chapter 7 provides an outlook for future development of the strategies described in this thesis and summarizes the results and conclusions of the experimental results that led to the development of the therapeutic, paclitaxel silicate-loaded, polymeric nanoparticles.

  7. Fumaric acid esters

    Microsoft Academic Search

    Martin Rostami Yazdi; Ulrich Mrowietz

    2008-01-01

    Several clinical studies have shown that systemic therapy with fumaric acid esters (FAEs) in patients with moderate to severe psoriasis is effective and has a good long-term safety profile. For therapeutic use, tablets with a defined mixture of FAEs (dimethylfumarate [DMF] and three different salts of monoethylfumarate) are registered in Germany. There is evidence that DMF is the most essential

  8. Silicic acid: boric acid complexes as wood preservatives

    Microsoft Academic Search

    Haruhiko Yamaguchi

    2003-01-01

    Wood was treated with a low molecular-weight silicic acid: boric acid agent and examined for increased resistance to termites and combustion. Wood treated with silicic acid only exhibited increased termite resistance, but not to the marked extent observed after treatment with a mixture of silicic and boric acids. Increasing the quantity of boric acid also increased the termite mortality rate

  9. Methyl esters in the fatty acid industry

    Microsoft Academic Search

    R. D. Farris

    1979-01-01

    Methyl esters, derived from natural fats or oils, can be used as alternatives to fatty acids in the production of a number\\u000a of derivatives. The derivatives that can be made from methyl esters include fatty alkanolamides, fatty alcohols, isopropyl\\u000a esters, and sucrose polyesters. By using methyl esters as the raw materials, several benefits may be realized, such as, the\\u000a ability

  10. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  11. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  12. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  13. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  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

    ... 2014-07-01 false Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721...Substances § 721.10679 Carboxylic acid, substituted alkylstannylene...

  15. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols. 721...Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols. (a...alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols...

  16. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols. 721...Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols. (a...alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols...

  17. Esters of valerenic acid as potential prodrugs

    PubMed Central

    Hintersteiner, Juliane; Haider, Maximilian; Luger, Denise; Schwarzer, Christoph; Reznicek, Gottfried; Jäger, Walter; Khom, Sophia; Mihovilovic, Marko D.; Hering, Steffen

    2014-01-01

    Valerenic acid (VA) is a ?2/3 subunit-specific modulator of ?-aminobutyric acid (GABA) type A (GABAA) receptors inducing anxiolysis. Here we analyze if VA-esters can serve as prodrugs and if different ester structures have different in vitro/in vivo effects. Modulation of GABAA receptors expressed in Xenopus oocytes was studied with 2-microelectrode-voltage-clamp. Anxiolytic effects of the VA-esters were studied on male C57BL/6N mice by means of the elevated plus maze-test; anticonvulsant properties were deduced from changes in seizure threshold upon pentylenetetrazole infusion. VA was detected in plasma confirming hydrolysis of the esters and release of VA in vivo. Esterification significantly reduced the positive allosteric modulation of GABAA (?1?3?2S) receptors in vitro. in vivo, the studied VA-ester derivatives induced similar or even stronger anxiolytic and anticonvulsant action than VA. While methylation and propylation of VA resulted in faster onset of anxiolysis, the action of VA-ethylester was longer lasting, but occurred with a significant delay. The later finding is in line with the longer lasting anticonvulsant effects of this compound. The estimated VA plasma concentrations provided first insight into the release kinetics from different VA-esters. This might be an important step for its future clinical application as a potential non-sedative anxiolytic and anticonvulsant. PMID:24680924

  18. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...polyamine condensate, phosphoric acid ester salts. 721.6200 Section 721.6200 ...polyamine condensate, phosphoric acid ester salts. (a) Chemical substances and significant...acid polyamine condensate, phosphate ester salts (PMNs P-90-1984 and...

  19. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  20. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  1. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  2. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  3. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  4. Poly(carbonate ester)s Based on Units of 6-Hydroxyhexanoic Acid and Glycerol

    E-print Network

    Poly(carbonate ester)s Based on Units of 6-Hydroxyhexanoic Acid and Glycerol Jesse B. Wolinsky materials. These include linear polyesters based on amino acids,9,10 sugars,11,12 or modified hydroxy acids(glycolic acid) and poly(lactic acid).26 Herein we report new copolymers based on 6-hydroxyhexanoic acid

  5. 77 FR 21676 - Silicic Acid, Sodium Salt etc.; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ...EPA-HQ-OPP-2011-0934; FRL-9333-6] Silicic Acid, Sodium Salt etc.; Tolerance Exemption...of a tolerance for residues of Silicic acid, sodium salt, reaction products with...permissible level for residues of Silicic acid, sodium salt, reaction products...

  6. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs...Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance...

  7. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs...Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance...

  8. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs...Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance...

  9. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2009-04-01 true Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs...Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance...

  10. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Sucrose fatty acid esters. 172.859 Section 172.859 Food and...Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified in this section may be...

  11. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859 Food and...Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified in this section may be...

  12. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs...Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance...

  13. 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

    ...New Uses for Specific Chemical Substances § 721...acid dialkyl ester, reaction products with alkenoic...generic). (a) Chemical substances and significant...reporting. (1) The chemical substances identified...acid dialkyl ester, reaction products with...

  14. 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

    ...New Uses for Specific Chemical Substances § 721...acid dialkyl ester, reaction products with alkenoic...generic). (a) Chemical substances and significant...reporting. (1) The chemical substances identified...acid dialkyl ester, reaction products with...

  15. Thermoset polymer-layered silicic acid nanocomposites

    NASA Astrophysics Data System (ADS)

    Wang, Zhen

    Nanocomposites are formed when phase mixing occurs on a nanometer length scale. Due to the improved phase morphology and interfacial properties, nanocomposites exhibit mechanical properties superior to conventional composites. Toyota researchers first demonstrated that organoclay could be exfoliated in a nylon-6 matrix to greatly improve the thermal and mechanical properties of the polymer, which has resulted in a practical application in the automobile industry. A great deal of research has been conducted on organic-inorganic hybrid composites in which smectite clays are used as reinforcement agents. However, little work has been devoted to derivatives of other layered inorganic solids. In the present work, the first examples of organic polymer-layered silicic acid nanocomposites have been prepared by formation of a cured epoxy polymer network in the presence of organo cation exchange forms of magadiite. The exfoliation of silicate nanolayers in the epoxy matrix was achieved by in-situ intragallery polymerization during the thermosetting process. In general, the tensile properties, solvent resistance, barrier properties and chemical stability of the polymer matrix are greatly improved by the embedded silicate nanolayers when the matrix is flexible (sub-ambient Tg). The improvement of properties are dependent on the silicate loading, the degree of nanolayer separation and interfacial properties. Interestingly, the exfoliation also affects the polymer elasticity in a favorable way. The mechanism leading to nanocomposite formation is proposed. One exfoliated epoxy-magadiite nanocomposite/composition possessed unique transparent optical properties. The exfoliation chemistry was successfully extended to the other members of the layered silicic acid family. A new approach also was developed to prepare thermoset epoxy polymer-layered silicate nanocomposites in which curing agents can be directly intercalated into the intragallery without the need for alkylammonium ions on the exchange sites. This new development has resulted in a greater improvement in the overall properties of thermoset polymer-clay nanocomposites. The exfoliation chemistry was extended further to other thermoset silicone polymer systems. The new polysiloxane-layered silicic acid nanocomposites were prepared with promising mechanical properties. Some fundamental chemistry and physics issues regarding nanocomposite formation were elucidated by this research work, particularly with regard to the relationship of microstructure and interfacial factors to the mechanical properties of the nanocomposites.

  16. Caffeic Acid Phenethyl Ester and Therapeutic Potentials

    PubMed Central

    Karim, Sabiha; Akram, Muhammad Rouf; Khan, Shujaat Ali; Azhar, Saira; Mumtaz, Amara; Bin Asad, Muhammad Hassham Hassan

    2014-01-01

    Caffeic acid phenethyl ester (CAPE) is a bioactive compound of propolis extract. The literature search elaborates that CAPE possesses antimicrobial, antioxidant, anti-inflammatory, and cytotoxic properties. The principal objective of this review article is to sum up and critically assess the existing data about therapeutic effects of CAPE in different disorders. The findings elaborate that CAPE is a versatile therapeutically active polyphenol and an effective adjuvant of chemotherapy for enhancing therapeutic efficacy and diminishing chemotherapy-induced toxicities. PMID:24971312

  17. Bioactive caffeic acid esters from Glycyrrhiza glabra.

    PubMed

    Dey, Surajit; Deepak, Mundkinajeddu; Setty, Manjunath; D'Souza, Prashanth; Agarwal, Amit; Sangli, Gopal Krishna

    2009-01-01

    Thin layer chromatography bioautography (using DPPH spray reagent) guided fractionation of Glycyrrhiza glabra led to the isolation of two caffeic acid derivative esters, viz. eicosanyl caffeate (1) and docosyl caffeate (2). The two compounds exhibited potent elastase inhibitory activity, with IC(50) values of 0.99 microg mL(-1) and 1.4 microg mL(-1) for 1 and 2, respectively. The compounds also showed moderate antioxidant activity in DPPH and ABTS scavenging assays. The results indicate a possible role of caffeic acid derivatives, in addition to flavonoids in the anti-ulcer properties of G. glabra. PMID:19921583

  18. Complexes of Alkyl Esters of Ethylidenediphosphonic Acids with Lanthanide Nitrates

    Microsoft Academic Search

    Vladislav Arabadzhiev; Jordanka Petrova; Erhard T. K. Haupt; Jürgen Kopf; Isabelle Nevoigt

    2008-01-01

    The lanthanide complexes LnL2(NO3)33a?c and 5a?c, where Ln is La, Ce and Sm and L are tetraethyl esters of ethylidenediphosphonic acid 1 (for complexes 3) and tetraisopropyl esters of ethylidenediphosphonic acid 4 (for complexes 5) were synthesized and characterized by elemental analysis, IR and NMR spectroscopy. The crystal structure of DyL2(NO3)37 (L is tetraisopropyl ester of methylenediphosphonic acid) was determined

  19. ?-Sulfonated fatty acids and esters: Manufacturing process, properties, and applications

    Microsoft Academic Search

    W. Stein; H. Baumann

    1975-01-01

    ?-Sulfonated fatty acid esters, because of their wide-range of application and biological properties, represent an interesting\\u000a class of surfactants. A technical method for the preparation of ?-sulfonated fatty acid esters is described. By using special\\u000a reaction conditions it is possible to ?-sulfonate saturated fatty esters directly without the use of solvents. The use of\\u000a gaseous SO3 gives the product in

  20. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...sulfuric acid ester, substituted amine salt. 721.7770 Section 721.7770 ...sulfuric acid ester, substituted amine salt. (a) Chemical substance and significant...sulfuric acid ester, substituted amine salt (PMN P-92-396) is subject to...

  1. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...sulfuric acid ester, substituted amine salt. 721.7770 Section 721.7770 ...sulfuric acid ester, substituted amine salt. (a) Chemical substance and significant...sulfuric acid ester, substituted amine salt (PMN P-92-396) is subject to...

  2. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... false Ethylene oxide adduct of fatty acid ester with pentaerythritol. 721...3680 Ethylene oxide adduct of fatty acid ester with pentaerythritol. ...generically as ethylene oxide adduct of fatty acid ester with pentaerythritol...

  3. 40 CFR 721.987 - Dialkylaminophenyl imino pyrazole acid ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Dialkylaminophenyl imino pyrazole acid ester (generic). 721.987...721.987 Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical...generically as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is...

  4. 40 CFR 721.987 - Dialkylaminophenyl imino pyrazole acid ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Dialkylaminophenyl imino pyrazole acid ester (generic). 721.987...721.987 Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical...generically as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is...

  5. 40 CFR 721.987 - Dialkylaminophenyl imino pyrazole acid ester (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Dialkylaminophenyl imino pyrazole acid ester (generic). 721.987...721.987 Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical...generically as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is...

  6. 40 CFR 721.987 - Dialkylaminophenyl imino pyrazole acid ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Dialkylaminophenyl imino pyrazole acid ester (generic). 721.987...721.987 Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical...generically as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is...

  7. 40 CFR 721.987 - Dialkylaminophenyl imino pyrazole acid ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Dialkylaminophenyl imino pyrazole acid ester (generic). 721.987...721.987 Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical...generically as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is...

  8. 40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. 721.10300 Section...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. (a) Chemical substance...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester (PMN...

  9. 40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. 721.10300 Section...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. (a) Chemical substance...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester (PMN...

  10. 40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. 721.10300 Section...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester. (a) Chemical substance...acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester (PMN...

  11. Preparation of {alpha},{beta}-unsaturated carboxylic acids and esters

    DOEpatents

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.

    1998-09-15

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

  12. Preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters

    DOEpatents

    Gogate, Makarand Ratnakar (Durham, NC); Spivey, James Jerry (Cary, NC); Zoeller, Joseph Robert (Kingsport, TN)

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

  13. MICROBIAL TRANSFORMATION OF ESTERS OF CHLORINATED CARBOXYLIC ACIDS

    EPA Science Inventory

    Two groups of compounds were selected for microbial transformation studies. In the first group were carboxylic acid esters having a fixed aromatic moiety and an increasing length of the alkyl component. Ethyl esters of chlorine-substituted carboxylic acids were in the second grou...

  14. Stereoselective Formation of Trisubstituted Vinyl Boronate Esters by the Acid-Mediated Elimination of ?-Hydroxyboronate Esters

    PubMed Central

    2015-01-01

    The copper-catalyzed diboration of ketones followed by an acid-catalyzed elimination leads to the formation of 1,1-disubstituted and trisubstituted vinyl boronate esters with moderate to good yields and selectivity. Addition of tosic acid to the crude diboration products provides the corresponding vinyl boronate esters upon elimination. The trisubstituted vinyl boronate esters are formed as the (Z)-olefin isomer, which was established by subjecting the products to a Suzuki–Miyaura coupling reaction to obtain alkenes of known geometry. PMID:24915498

  15. Synthesis and Physical Properties of Estolide Ester Using Saturated Fatty Acid and Ricinoleic Acid

    PubMed Central

    Salimon, Jumat; Nallathamby, Neeranjini; Salih, Nadia; Abdullah, Bashar Mudhaffar

    2011-01-01

    A study was conveyed to produce estolide ester using ricinoleic acid as the backbone. The ricinoleic acid reacted with saturated fatty acid from C8–C18. These reactions were conducted under vacuum at 60°C for 24?h without solvent. The reaction used acid catalyst, sulphuric acid. The new saturate ricinoleic estolide esters show superior low-temperature properties (?52 ± 0.08°C) and high flash point (>300°C). The yield of the neat estolide esters ranged from 52% to 96%. The viscosity range was 51 ± 0.08 to 86 ± 0.01?cp. These new saturated estolide esters were also compared with saturated branched estolide esters. PMID:22007150

  16. Bioavailability Improvement of Mycophenolic Acid Through Amino Ester Derivatization

    Microsoft Academic Search

    William A. Lee; Leo Gu; Andrew R. Miksztal; Nancy Chu; Kwan Leung; Peter H. Nelson

    1990-01-01

    The potential bioavailability improvement of mycophenolic acid (MPA), 1, through ester derivatization was evaluated in monkeys at a dose of 20 mg\\/kg in this study. The acetyl solketal ester 3 was found to have excellent partition properties but poor aqueous solubility. Thus, even though it can be converted rapidly to MPA by plasma and liver enzymes, it showed poor oral

  17. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

  18. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

  19. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

  20. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2009-04-01 true Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

  1. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Glyceryl-lacto esters of fatty acids. 172.852 Section 172.852 Food and...172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and...

  2. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...reporting. (1) The chemical substance identified as hexadecanoic acid, ethenyl ester (PMN P-97-302; CAS No. 693-38-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  3. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...reporting. (1) The chemical substance identified as hexadecanoic acid, ethenyl ester (PMN P-97-302; CAS No. 693-38-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  4. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...reporting. (1) The chemical substance identified as hexadecanoic acid, ethenyl ester (PMN P-97-302; CAS No. 693-38-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  5. ESTIMATION OF CARBOXYLIC ACID ESTER HYDROLYSIS RATE CONSTANTS

    EPA Science Inventory

    SPARC chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid esters from molecular structure. The energy differences between the initial state and the transition state for a molecule of interest are factored into internal and external...

  6. Treatment of oil-containing wastewater using activated silicic acid as a flocculant

    Microsoft Academic Search

    L. V. Gandurina; E. I. Gervits

    2009-01-01

    Activated silicic acid was compared with polyacrylamide for use as a flocculant in treating refinery wastewater. Silicic acid was obtained by treating sodium silicate with aluminum sulfate and tested by the jar-test procedure. After adding the flocculant, the oily matter content from wastewater was determined by infrared spectroscopy. Silicic acid was found to be as effective as polyacrylamide but at

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  10. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  11. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  12. Pressure leaching of synthetic zinc silicate in sulfuric acid medium

    Microsoft Academic Search

    Shanming He; Jikun Wang; Jiangfeng Yan

    2011-01-01

    The pressure leaching of synthetic zinc silicate is studied in the present paper. Five key parameters were explored, namely, sulfuric acid concentration, the final pH of leaching pulp, leaching temperature, water content and iron addition. The experimental results obtained show that sulfuric acid concentration, the final pH, iron addition, water content and leaching temperature have significant effect on the leaching

  13. Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

    Microsoft Academic Search

    Rainer Kalscheuer; Tim Stoveken; Heinrich Luftmann; Ursula Malkus; Rudolf Reichelt; Alexander Steinbuchel

    2006-01-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is

  14. Usage of methyl ester of tall oil fatty acids and resinic acids as alternative diesel fuel

    Microsoft Academic Search

    Ali Keskin; Abdulkadir Ya?ar; Metin Gürü; Duran Alt?parmak

    2010-01-01

    In the experimental study, tall oil fatty and resinic acids were investigated as alternative diesel fuels. The fatty acids, obtained by distilling the crude tall oil, were esterified with methanol in order to obtain tall oil methyl ester (biodiesel). Blends of the methyl ester, resinic acids and diesel fuel were prepared for test fuels. Performance and emission tests of the

  15. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Boric acid, alkyl and substituted alkyl esters...Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl esters... (1) The chemical substance boric acid, alkyl and substituted...

  16. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Boric acid, alkyl and substituted alkyl esters...Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl esters... (1) The chemical substance boric acid, alkyl and substituted...

  17. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Boric acid, alkyl and substituted alkyl esters...Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl esters... (1) The chemical substance boric acid, alkyl and substituted...

  18. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Boric acid, alkyl and substituted alkyl esters...Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl esters... (1) The chemical substance boric acid, alkyl and substituted...

  19. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Boric acid, alkyl and substituted alkyl esters...Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl esters... (1) The chemical substance boric acid, alkyl and substituted...

  20. 78 FR 70878 - Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester With 2-Methyloxirane Polymer With Oxirane...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ...EPA-HQ-OPP-2013-0526; FRL-9903-18] Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester...tolerance for residues of Octadecanoic Acid, 12-Hydroxy-, Homopolymer, Ester...permissible level for residues of Octadecanoic Acid, 12-Hydroxy-, Homopolymer,...

  1. Effects of high-melting methyl esters on crystallization properties of fatty acid methyl ester mixtures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is a renewable alternative diesel fuel made from vegetable oils and animal fats. The most common form of biodiesel in the United States are fatty acid methyl esters (FAME) from soybean, canola, and used cooking oils, waste greases, and tallow. Cold flow properties of biodiesel depend on th...

  2. 76 FR 7703 - 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4-Butanediol, Adipic Acid, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ...FRL-8863-9] 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4- Butanediol, Adipic Acid, and Hexamethylene Diisocyanate; Exemption...residues of 1,4-benzenedicarboxylic acid, dimethyl ester, polymer with...

  3. Three new fatty acid esters from the mushroom Boletus pseudocalopus.

    PubMed

    Kim, Ki Hyun; Choi, Sang Un; Lee, Kang Ro

    2012-06-01

    A bioassay-guided fractionation and chemical investigation of a MeOH extract of the Korean wild mushroom Boletus pseudocalopus resulted in the identification of three new fatty acid esters, named calopusins A-C (1-3), along with two known fatty acid methyl esters (4-5). These new compounds are structurally unique fatty acid esters with a 2,3-butanediol moiety. Their structures were elucidated through 1D- and 2D-NMR spectroscopic data and GC-MS analysis as well as a modified Mosher's method. The new compounds 1-3 showed significant inhibitory activity against the proliferation of the tested cancer cell lines with IC(50) values in the range 2.77-12.51 ?M. PMID:22271425

  4. Phosphate ester inhibitors solve naphthenic acid corrosion problems

    SciTech Connect

    Babaian-Kibala, E. (Nalco Chemical Co., Sugar Land, TX (United States))

    1994-02-28

    Crude oils containing naphthenic acids can cause a variety of corrosion problems in any of several process areas. But because of the complexity of naphthenic acid corrosion, no routine technique is available for predicting corrosion from this source. Certain high-temperature corrosion inhibitors with a general phosphate ester structure have shown good mitigation of naphthenic acid corrosion in commercial applications. A description of two such cases will help refiners know what to look for to prevent similar occurrences in their plants.

  5. 75 FR 70254 - Typographical Error in Summary Notice of Filing in Docket for Polymerized Fatty Acid Esters With...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ...Filing in Docket for Polymerized Fatty Acid Esters With Aminoalcohol Alkoxylates...Petition (PP) 0E7699 for polymerized fatty acid esters with aminoalcohol alkoxylates...Petition (PP) 0E7699 for polymerized fatty acid esters with aminoalcohol...

  6. 40 CFR 721.990 - 1,4-Benzedicarboxylic acid, dimethyl ester, polymer with 1,4 - butanediol, cyclized.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...4-Benzedicarboxylic acid, dimethyl ester, polymer with 1,4 - butanediol, cyclized...4-Benzedicarboxylic acid, dimethyl ester, polymer with 1,4 - butanediol, cyclized...4-benzedicarboxylic acid, dimethyl ester, polymer with 1,4 - butanediol,...

  7. 78 FR 5761 - Proposed Modification of Significant New Uses of Ethaneperoxoic Acid, 1,1-Dimethylpropyl Ester

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ...Significant New Uses of Ethaneperoxoic Acid, 1,1-Dimethylpropyl Ester AGENCY...substance identified as ethaneperoxoic acid, 1,1-dimethylpropyl ester, which...substance identified as ethaneperoxoic acid, 1,1-dimethylpropyl ester (PMN...

  8. Silicic acid leakage from the Southern Ocean: Opposing effects of nutrient uptake and oceanic circulation

    E-print Network

    Pahnke, Katharina

    Silicic acid leakage from the Southern Ocean: Opposing effects of nutrient uptake and oceanic March 2007; accepted 14 May 2007; published 3 July 2007. [1] Studies invoking the silicic acid leakage correlation between the silicic acid content of Southern Ocean surface waters and opal deposition at low

  9. Highly unsaturated fatty acids. III. Isolation of methyl eicosapentaenoate, ethyl docosapentaenoate, and ethyl docosahexaenoate from cod liver oil esters by chromatography

    Microsoft Academic Search

    Ahmed M. Abu-Nasr; Ralph T. Holman

    1954-01-01

    Summary  a) Displacement chromatography using a charcoal-isopropanol-methyl behenate system has been successfully applied to the isolation\\u000a of docosahexaenoic acid and ethyl docosahexaenoate from cod liver oil concentrates.\\u000a \\u000a b) Methyl eicosapentaenoate was isolated from cod liver oil methyl esters by combined elution chromatography on silicic acid\\u000a and displacement chromatography.\\u000a \\u000a \\u000a \\u000a c) Using silicic acid as adsorbent and petroleum ether-chloroform as solvent, ethyl docosapentaenoate

  10. Diffusion of diphosphoric acid tetraethyl ester (1); air (2)

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) diphosphoric acid tetraethyl ester; (2) air

  11. New Eudesmenoic Acid Methyl Ester from Artemisia Selengensis

    Microsoft Academic Search

    J. F. Hu; Y. Lu; B. Zhao; X. Z. Feng; M. T. Hamann

    2001-01-01

    The aerial parts of Artemisia selengensis yielded a new eudesmenoic acid methyl ester together with a known eudesmanolide. The structures were elucidated by spectroscopic methods. The relative stereochemistry of the title compound was further supported by the result of a successful single-crystal X-ray diffraction analysis.

  12. Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural product dihydroferulic acid (DFA, 1) and the synthesized DFA methyl (4a), ethyl (4b), propyl (4c), hexyl (4d), octyl (4e), and decyl (4f) esters were examined for antifungal activity. Test fungi included Saccharomyces cerevisiae (wild type, and deletion mutants slt2delta and bck1delta), ...

  13. Thermal decomposition of tert-butyl ester of triethylsilylperacetic acid

    Microsoft Academic Search

    T. N. Brevnova; N. S. Vyazankin; A. M. Rabinovich; O. F. Rachkova

    1971-01-01

    A study was made of the decomposition products of the tert-butyl ester of triethylsilylperacetic acid in cumene, n-nonane and tetraethylstannane. In the latter case the processes of generating the free radicals (C2H5)3SiCH2COO and (CH3)3CO, and their subsequent decomposition, are markedly suppressed.

  14. Treatment of disseminated granuloma annulare with fumaric acid esters

    Microsoft Academic Search

    Alexander Kreuter; Thilo Gambichler; Peter Altmeyer; Norbert H Brockmeyer

    2002-01-01

    BACKGROUND: Granuloma annulare is a granulomatous disease of unknown etiology. Various therapies have been tried in disseminated granuloma annulare (DGA), including corticosteroids, several variants of psoralen plus ultraviolet-A radiation, ultraviolet- A1 radiation, systemic retinoids, and dapsone, with variable success. We report a patient with recalcitrant DGA who was treated with fumaric acid esters (FAE). CASE PRESENTATION: A 40-year old Caucasian

  15. Inhibition of Dendritic Cell Differentiation by Fumaric Acid Esters

    Microsoft Academic Search

    Kejian Zhu; Ulrich Mrowietz

    2001-01-01

    Fumaric acid esters have proved to be effective for the systemic treatment of severe psoriasis vulgaris. These compounds have been shown to induce a Th2-like cytokine secretion pattern in T cells and to reduce keratinocyte proliferation in vitro. Dendritic cells seem to be of major importance as regulatory cells driving the psoriatic tissue reaction. Monocytes or CD34-positive myeloid progenitor cells

  16. Dielectric properties of biodegradable polylactic acid and starch ester

    Microsoft Academic Search

    N. Hirail; Y. Maeno; H. Tamura; D. Kaneko; T. Tanaka; Y. Ohki; Y. Tajitsu; M. Kohtoh; S. Okabe

    2004-01-01

    In order to examine the applicability of biodegradable polymers to the fields of electrical insulation, several dielectric properties of two typical biodegradable polymers, polylactic acid (PLA) and starch ester (SE), are examined. A fairly larger amount of space charge is accumulated in both polymers in comparison to low-density polyethylene (LDPE). This seems partly due to the presence of hydroxyl and

  17. Process for fatty acid methyl esters by dual reactive distillation

    Microsoft Academic Search

    Alexandre C. Dimian; Florin Omota; Anton A. Kiss

    2007-01-01

    Fatty acid methyl esters (FAME) , valuable oleo-chemicals and main constituent of biodiesel, can be manufactured in a continuous process based on reactive distillation and solid catalyst. A central problem is the effective water removal. In this work we propose a novel approach, namely dual esterification with a mixture of methanol and long-chain alcohol, as 2-ethylhexanol, which plays the role

  18. Effect of formic acid and benzoic acid esters on grass preservation

    E-print Network

    Paris-Sud XI, Université de

    Effect of formic acid and benzoic acid esters on grass preservation A Rauramaa A Tommila J Ltd, Espoo Reseach Centre, PO Box 44, 02271 Espoo, Finland Formic acid is known to improve silage hygienic quality. Formic acid based additive containing propionic and benzoic acids inhibits more

  19. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

  20. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

  1. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection...derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant...derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to...

  2. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food...573.640 Methyl esters of higher fatty acids. The food additive methyl esters of higher fatty acids may be safely used in animal feeds in...

  3. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food...573.640 Methyl esters of higher fatty acids. The food additive methyl esters of higher fatty acids may be safely used in animal feeds in...

  4. 75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-25

    ...EPA-HQ-OPP-2010-0429; FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane...requirement of a tolerance for residues of acetic acid ethenyl ester, polymer with oxirane...permissible level for residues of acetic acid ethenyl ester, polymer with oxirane...

  5. 76 FR 8895 - Polymerized Fatty Acid Esters With Aminoalcohol Alkoxylates; Exemption From the Requirement of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ...EPA-HQ-OPP-2010-0275; FRL-8860-8] Polymerized Fatty Acid Esters With Aminoalcohol Alkoxylates...tolerance for residues of polymerized fatty acid esters with aminoalcohol alkoxylates...tolerance for residues of polymerized fatty acid esters with aminoalcohol...

  6. Gas chromatographic analysis of fatty acid methyl esters

    Microsoft Academic Search

    K. Eder

    1995-01-01

    The full process of fatty acid methyl ester (FAME) analysis consists of esterification of lipids, and of injection, separation, identification and quantitation of the FAMEs. In order for the required accuracy and precision to be attained, each of these steps has to be optimized.Esterification of lipids can be carried out with several reagents based on acid-catalysed or base-catalysed reactions. The

  7. The amplified distillation of methyl esters of fatty acids

    Microsoft Academic Search

    A. W. Weitkamp

    1947-01-01

    Summary  Amplified distillation is a useful technique for the quantitative analysis of mixtures of fatty acid esters, especially for\\u000a the detection and estimation of minor components and for the analysis of small samples. The amplified distillation of free\\u000a fatty acids is largely limited to qualitative work on account of the formation of azeotropes with mineral oils.

  8. Encapsulating fatty acid esters of bioactive compounds in starch

    NASA Astrophysics Data System (ADS)

    Lay Ma, Ursula Vanesa

    Interest in the use of many bioactive compounds in foods is growing in large part because of the apparent health benefits of these molecules. However, many of these compounds can be easily degraded during processing, storage, or their passage through the gastrointestinal tract before reaching the target site. In addition, they can be bitter, acrid, or astringent, which may negatively affect the sensory properties of the product. Encapsulation of these molecules may increase their stability during processing, storage, and in the gastrointestinal tract, while providing controlled release properties. The ability of amylose to form inclusion complexes and spherulites while entrapping certain compounds has been suggested as a potential method for encapsulation of certain molecules. However, complex formation and spherulitic crystallization are greatly affected by the type of inclusion molecules, type of starch, and processing conditions. The objectives of the present investigation were to: (a) study the effect of amylose, amylopectin, and intermediate material on spherulite formation and its microstructure; (b) investigate the formation of amylose and high amylose starch inclusion complexes with ascorbyl palmitate, retinyl palmitate, and phytosterol esters; (c) evaluate the ability of spherulites to form in the presence of fatty acid esters and to entrap ascorbyl palmitate, retinyl palmitate, and phytosterol esters; and (d) evaluate the effect of processing conditions on spherulite formation and fatty acid ester entrapment. Higher ratios of linear to branched molecules resulted in the formation of more and rounder spherulites with higher heat stability. In addition to the presence of branches, it appears that spherulitic crystallization is also affected by other factors, such as degree of branching, chain length, and chain length distribution. Amylose and Hylon VII starch formed inclusion complexes with fatty acid esters of ascorbic acid, retinol, or phytosterols. However, only retinyl palmitate formed a complex with amylopectin. In general, ascorbyl palmitate resulted in the highest complexation, followed by retinyl palmitate and phytosterol ester. The presence of native lipids in Hylon VII starch did not inhibit complex formation. On the contrary, native lipids appear to increase the complexation yield and thermal stability of the starch-fatty acid ester inclusion complexes, possibly due to the formation of ternary complexes. From the three fatty acid esters studied, only ascorbyl palmitate was entrapped in starch spherulites. Various structures including round spherulites, various sizes of torus-shape spherulites, non-spherulitic birefringent and non-birefringent particles, "balloon" morphologies, and gel-like material were formed depending on processing conditions. However, only the torus-shape spherulites, and some non-spherulitic birefringent and non-birefringent particles showed ascorbyl palmitate entrapment. The % yield of the precipitate increased with higher % of added Hylon VII, and decreased with higher heating temperature and faster cooling rates. The amount of entrapped ascorbyl palmitate in the starch precipitate seems to be governed by the amount of this compound added during processing. This study showed that starch can form inclusion complexes with fatty acid esters which may be used for the delivery of certain bioactive molecules. In addition, encapsulation of fatty acid esters in starch spherulites may be a good potential delivery system for water soluble bioactive molecules. However, further research is necessary to gain a better understanding of the type of molecules that can be entrapped in starch spherulites, and the factors affecting spherulitic crystallization and bioactive compound entrapment.

  9. Synthesis of chiral N-protected amino acid esters by the use of UNCAs

    Microsoft Academic Search

    P. Chevallet; J.-A. Fehrentz; K. Kiec-Kononowicz; C. Devin; J. Castel; A. Loffet; J. Martinez

    1996-01-01

    An easy synthesis of N-protected amino acid esters, including tert-butyl esters, is described by the use of urethane N-protected carboxyanhydrides (UNCAs). Treating UNCAs with tert-butanol in the presence of potassium bicarbonate at 45°C yielded the corresponding N-protected amino acid tert-butyl esters in a very simple way. Benzyloxycarbonyl and tert-butyloxycarbonyl N-protected amino acid tert-butyl esters have been obtained by this procedure.

  10. Comparison Of Asymmetric Hydrogenations Of Unsaturated- Carboxylic Acids And -Esters

    PubMed Central

    Khumsubdee, Sakunchai; Burgess, Kevin

    2013-01-01

    As methodology development matures it can be difficult to discern the most effective ways of performing certain transformations from the rest. This review summarizes the most important contributions leading to asymmetric hydrogenations of simple unsaturated-acid and ester substrates, with the objective of highlighting at least the best types of catalysts for each. Achievements in the area are described and these reveal situations where further efforts should be worthwhile, and ones where more research is only likely to give diminishing returns. In general, our conclusions are that the most useful types of catalysts for unsaturated-acids and -esters tend to be somewhat different, simple substrates have been studied extensively, and the field is poised to address more complex reactions. These could be ones involving alternative, particularly cyclic, structures, chemoselectivity issues, and more complex substrate stereochemistries. PMID:24729943

  11. ?-Ketoamino acid ester derivatives as promising MAO inhibitors.

    PubMed

    El-Faham, Ayman; Zainab Al Marhoon; Abdel-Megeed, Ahmed; Khattab, Sherine N; Bekhit, Adnan A; Albericio, Fernando

    2015-01-01

    ?-Ketoamino acid ester 2-[2-(2-acetamidophenyl)-2-oxoacetamido] and 2-[4-(2-(2-acetamidophenyl)-2-oxoacetamido)benzamido] derivatives were synthesized via the ring opening of N-acetylisatin under mild conditions. These compounds were then examined for their capacity to inhibit monoamine oxidase (MAO). The inhibition profile was found to be competitive for compounds 4d, 6a, 6b and 6f, which showed MAO-A selectivity. Observation of the docked positions of these compounds revealed interactions with many residues previously reported to have an effect on the inhibition of the enzyme. Our findings indicate that the members of this family of ?-ketoamino acid esters are promising MAO inhibitors. PMID:25466194

  12. Performance and physicochemical properties of ?-sulfo fatty acid methyl esters

    Microsoft Academic Search

    Teruhisa Satsuki; Kenji Umehara; Yuji Yoneyama

    1992-01-01

    The detergency properties of ?-sulfonated fatty acid methyl esters (?-SFMe) were evaluated and compared to those of conventional\\u000a anionic surfactants by using a model heavy-duty detergent formulation. Several physicochemical properties of surfactants were\\u000a measured to investigate the effective factors on detergency. ?-SFMe showed good detergency performance under various washing\\u000a conditions. These results were considered to correlate well with the good

  13. Preparation of thio and seleno sugar esters of dimethylantimonous acid

    E-print Network

    Baimbridge, Charles Lynn

    1975-01-01

    trichloride with excess methyl Grignard reagent followed by distillation of trimethylstibine ~ Addition of halogen to the stibine gives quantitative yields of the trimethylantimony dihalide. Triorganylstibines are strong reducing agents and the lower...PREPARATION OF THIO AND SELENO SUGAR ESTERS OF DIMETHYLANTIMONOUS ACID A Thesis by CHARLES LYNN BAIMBRIDGE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER...

  14. Surface tension determinations of some saturated fat acid methyl esters

    Microsoft Academic Search

    C. S. Nevin; P. M. Althouse; H. O. Triebold

    1951-01-01

    Summary  Methyl esters of saturated naturally occurring fat acids from C6 through C18 were prepared and purified by fractional distillation. Refractive indices were used as a measure of their purity. A micro\\u000a surface tension apparatus was constructed to comply with a modified capillary rise method devised by Ferguson. The surface\\u000a tensions of water and of benzene were determined at several temperatures.

  15. Fatty acid analyses of known mixtures of purified methyl esters

    Microsoft Academic Search

    A. Richard Baldwin; Herbert E. Longenecker

    1945-01-01

    Summary  Mixtures of known composition of purified methyl esters of lauric, myristic, palmitic, stearic, oleic, linoleic and linolenic\\u000a acids have been prepared. Fractional distillation under reduced pressure followed by spectrophotometric determination of methyl\\u000a linoleate and methyl linolenate in each of the fractions and determination of iodine values and saponification equivalents\\u000a allowed calculation of the compositions which agreed well with the compositions

  16. Fatty acid methyl ester profiles of bat wing surface lipids.

    PubMed

    Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-11-01

    Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration. PMID:25227993

  17. Preparation of malvalic and sterculic acid methyl esters from Bombax munguba and Sterculia foetida seed oils

    Microsoft Academic Search

    E. Fehling; S. Schönwiese; E. Klein; K. D. Mukherjee; N. Weber

    1998-01-01

    A method has been developed for the preparation of highly pure malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acid methyl esters starting from Bombax munguba and Sterculia foetida seed oils. The methyl esters of these oils were prepared by sodium methylate-catalyzed transmethylation followed by cooling\\u000a (6°C) the hexane solution of crude methyl esters and separation of insoluble fatty acid methyl esters by

  18. Synthesis of Alkyl Methylphosphonic Acid Esters

    SciTech Connect

    Mong, Gary M.; Harvey, Scott D.; Campbell, James A.

    2005-08-01

    This manuscript describes a simple synthesis and purification of cyclohexyl methylphosphonic and isopropyl methylphosphonic acids that provides high purity (>95% purity) product in gram quantities. Based on needs for improved analytical methods for indirect detection of nerve agent use, there is an increasing demand for these nerve agent hydrolysis products. These products are not commercially available. Synthesis is based on reaction of equimolar amounts of alcohol with methylphosphonic dichloride in toluene followed by the addition of excess water (two mole equivalents). The product was then extracted from the resulting aqueous layer into chloroform. The extraction scheme proved highly effective in removing unreacted starting materials and reaction by-products.

  19. Silicic acid biogeochemistry in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-05-01

    Silicon is an essential nutrient for the growth of siliceous phytoplankton, which accounts for a significant amount of marine primary production. Constraints on silicic acid limit primary production and carbon export, so biogeochemical silicon cycling influences the carbon cycle and climate. Silicon cycling has been studied mostly in iron-limited regions of the ocean, and not much is known about the effects of iron availability on silicon cycling in coastal upwelling systems. Pichevin et al. investigated nutrient profiles and sedimentary records from the Gulf of California, which is not limited by iron year-round. They found that iron limitation even in this type of setting is an important factor in silicon cycling in coastal upwelling regions. (Paleoceanography, doi:10.1029/2011PA002237, 2012)

  20. Enantiomeric enrichment of ?-amino acid derivatives: recrystallization of N-Fmoc ?-amino acid tert-butyl esters

    Microsoft Academic Search

    Martin J O'Donnell; Francisca Delgado

    2001-01-01

    The optical purity of products derived from enantioselective reactions of the benzophenone imine of glycine tert-butyl esters can often be improved by conversion to the N-Fmoc ?-amino acid tert-butyl esters followed by simple recrystallization.

  1. Stimulation of insulin release caused by intraduodenal administration of succinic acid methyl esters.

    PubMed

    Garcia-Martinez, J A; Villanueva-Peñacarrillo, M L; Valverde, I; Malaisse, W J

    1995-01-01

    The methyl esters of succinic and glutamic acid are currently under investigation as possible tools for stimulation of insulin biosynthesis and release in non-insulin-dependent diabetes mellitus. The present study deals with the secretory response of the pancreatic B-cell to these esters after intraduodenal administration to anaesthetized rats. The dimethyl ester of succinic acid and, to a lesser extent, its monomethyl ester both increased the plasma insulin concentration, whilst the dimethyl ester of glutamic acid virtuality failed to do so. The stimulation of insulin release, caused by the dimethyl ester of succinic acid, was faster and more pronounced than that evoked by an equimolar amount of glucose. The present study thus reveals that the latter ester, when administered via the gastrointestinal tract, evokes a more brisk and more ample secretory response of the pancreatic B-cell than that evoked by glucose. PMID:8849306

  2. Analysis of intact cholesteryl esters of furan Fatty acids in cod liver.

    PubMed

    Hammann, Simon; Wendlinger, Christine; Vetter, Walter

    2015-06-01

    Furan fatty acids (F-acids) are a class of natural antioxidants with a furan moiety in the acyl chain. These minor fatty acids have been reported to occur with high proportions in the cholesteryl ester fraction of fish livers. Here we present a method for the direct analysis of intact cholesteryl esters with F-acids and other fatty acids in cod liver lipids. For this purpose, the cholesteryl ester fraction was isolated by solid phase extraction (SPE) and subsequently analyzed by gas chromatography with mass spectrometry (GC/MS) using a cool-on-column inlet. Pentadecanoic acid esterified with cholesterol was used as an internal standard. GC/MS spectra of F-acid cholesteryl esters featured the molecular ion along with characteristic fragment ions for both the cholesterol and the F-acid moiety. All investigated cod liver samples (n = 8) showed cholesteryl esters of F-acids and, to a lower degree, of conventional fatty acids. By means of GC/MS-SIM up to ten F-acid cholesteryl esters could be determined in the samples. The concentrations of cholesteryl esters with conventional fatty acids amounted to 78-140 mg/100 g lipids (mean 97 mg/100 g lipids), while F-acid cholesteryl esters were present at 47-270 mg/100 g lipids (mean 130 mg/100 g lipids). PMID:25916237

  3. ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

  4. Autoxidation rates of various esters of safflower oil and linoleic acid

    Microsoft Academic Search

    Kazuo Miyashita; Toru Takagi

    1988-01-01

    Autoxidation rates of five types of safflower oil esters increased in the following order: monoacylglycerol (MG), methyl ester\\u000a (ME), diacylglycerol (DG), triacylglycerol (TG) and sucrose ester (SE). The differences in autoxidation rate were confirmed\\u000a by measuring autoxidation of similar esters of linoleic acid. The order of the oxidation rates corresponded to the number\\u000a of acyl groups per molecule. This relationship

  5. Jojoba oil wax esters and derived fatty acids and alcohols: Gas chromatographic analyses

    Microsoft Academic Search

    Thomas K. Miwa

    1971-01-01

    HCl-catalyzed ethanolysis followed by saponification readily surmounts the resistance of long chain wax esters to direct hydrolysis\\u000a by alkali. Additionally, choosing ethyl instead of methyl esters allows baseline separations between long-chain alcohols and\\u000a corresponding esters in gas liquid chromatographic (GLC) analysis of total alcohol and acid components before saponification.\\u000a Liquid wax esters were analyzed on a temperature-programmed 3% OV-1 silicone

  6. Toxicokinetics of Phthalic Acid: The Common Final Metabolite of Phthalic Acid Esters in Rats

    Microsoft Academic Search

    Duck Soo Lim; Bum Soo Shin; Sun Dong Yoo; Hyung Sik Kim; Seung Jun Kwack; Mi Young Ahn; Byung Mu Lee

    2007-01-01

    The toxicokinetic profiles of phthalic acid (PA), which is the common final metabolite of phthalic acid esters (PAE), were studied in rats after orally administering doses 20, 100, or 500 mg\\/kg. Concentrations of PA were determined in serum or urine by high-performance liquid chromatography (HPLC). The plasma concentrations of PA showed a biexponential increase following oral administration of doses ranging

  7. Preparation of thio and seleno sugar esters of dimethylantimonous acid 

    E-print Network

    Baimbridge, Charles Lynn

    1975-01-01

    the addition of tetramethyldistibine to acetylated, benzoylated, and free hydroxy sugar di. selenides and to the acetyl- ated sugar disulfide: OR CHZ CH3 ~ SS ? SH CH3 CH3 CH2OR ~CH3 0 X-Sb 2 OR RO CH 3 OR (X=S, R=Ac; X Se, R=H, Ac, gz) The use... with sugar derivatives to yield the chalco- geno sugar ester of dimethylantimonous acid as shown below: CH2OR CH3 X ? Sb R CH3 RO OR ( X = S, Se p e R = H& CH ~-, 4C- 1-S or I-Se-dimethylstibino-I-chalcogeno-S-D- glucopyranose derivative...

  8. Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

    PubMed Central

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-01-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms. PMID:16461689

  9. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

    PubMed

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms. PMID:16461689

  10. Solid superacid catalyzed fatty acid methyl esters production from acid oil

    Microsoft Academic Search

    Yan Li; Xiao-Dong Zhang; Li Sun; Min Xu; Wen-Guang Zhou; Xiao-Hui Liang

    2010-01-01

    A solid superacid catalyst was evaluated for the production of fatty acid methyl esters (FAMEs) from acid oil containing about 60wt.% free fatty acids. It was demonstrated that SO42-\\/ZrO2–TiO2\\/La3+ was an effective catalyst for simultaneous transesterification and esterification. The optimization of reaction parameters was performed, showing that maximum yield of above 90% could be obtained under the conditions that molar

  11. Carboxypeptidase Y catalyzed peptide synthesis using amino acid alkyl esters as amine components

    Microsoft Academic Search

    Fred Widmer; Klaus Breddam; Jack T. Johansen

    1980-01-01

    Carboxypeptidase Y catalyzed transacylation reactions between N-protected amino acid methyl esters or peptide methyl esters\\u000a as initial acyl components and methyl, ethyl, isopropyl or tert.-butyl esters of different ?-amino acids as amine components\\u000a are described. The yield of peptide bond formation and the extent of oligomerization of the amine components both depend on\\u000a the nature of their side chain as

  12. Complexes of polyadenylic acid and the methyl esters of amino acids

    NASA Technical Reports Server (NTRS)

    Khaled, M. A.; Mulins, D. W., Jr.; Swindle, M.; Lacey, J. C., Jr.

    1983-01-01

    A study of amino acid methyl esters binding to polyadenylic acid supports the theory that the genetic code originated through weak but selective affinities between amino acids and nucleotides. NMR, insoluble complex analysis, and ultraviolet spectroscopy are used to illustrate a correlation between the hydrophybicities of A amino acids and their binding constants, which, beginning with the largest, are in the order of Phe (having nominally a hydrophobic AAA anticodon), Ile, Leu, Val and Gly (having a hydrophilic anticodon with no A). In general, the binding constants are twice the values by Reuben and Polk (1980) for monomeric AMP, which suggests that polymer amino acids are interacting with only one base. No real differences are found betwen poly A binding for free Phe, Phe methyl ester or Phe amide, except that the amide value is slightly lower.

  13. Preparation of fatty acid methyl esters and dimethylacetals from lipids with boron fluoride-methanol

    Microsoft Academic Search

    WILLIAM R. MORRISON; LLOYD M. SMITH

    SUMMARY Fatty acid methyl esters and dimethylacetals suitable for gas chromatographic analysis were prepared by treatment of lipids with boron fluoride-methanol (140 g BFI per liter of methanol). This reagent is stable and easy to handle. Reaction conditions were investigated for triglycerides, di- glycerides, monoglycerides, free fatty acids, sterol esters, phos- phatidyl ethanolamines, phosphatidyl serines, phosphatidyl 'cholines, monophosphoinositides, monogalactosyl glycerides,

  14. Experimental and Computational Thermochemical Study of 2-and 3-Thiopheneacetic Acid Methyl Esters

    E-print Network

    Chickos, James S.

    Experimental and Computational Thermochemical Study of 2- and 3-Thiopheneacetic Acid Methyl Esters acid methyl esters. The enthalpies of combustion and vaporization were measured by a rotating distillation.7 Thus, different studies related to their biodegradation8 and cata- lytic dehydrodesulfuration9

  15. ?-sulfonated fatty acid esters: II. Solution behavior of ?-sulfonated fatty acid polyethylene glycol esters

    Microsoft Academic Search

    Tomomichi Okano; Naoyuki Egawa; Masami Fujiwara; Masahiro Fukuda

    1996-01-01

    Sodium ?-sulfonated, fatty acid polyethylene glycol monoesters [C\\u000a m\\u000a H2m+1CH(SO3Na)COO(C2H4O)\\u000a n\\u000a H] and diesters [C\\u000a m\\u000a H2m+1CH(SO3Na)COO(C2H4O)\\u000a n\\u000a COCH(SO3Na)C\\u000a m\\u000a H2m+1], wherem=10–16 andn=1–35, were prepared by esterification of ?-sulfonated, fatty acids with polyethylene glycols, followed by neutralization\\u000a with NaOH. Crude products were purified by reversed-phase column chromatography on an octadecyl-modified silica gel. Characteristic\\u000a solution behavior of these ?-sulfonated fatty acid

  16. Energy-rich glyceric acid oxygen esters - Implications for the origin of glycolysis

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.; Hsu, Victor

    1990-01-01

    The apparent Gibbs free energy change (GFEC) of hydrolysis (pH 7) of the 2- and 3-O-glyceroyl esters of 2- and 3-O-L-glyceroyl-L-glyceric acid methyl ester were measured at 25 C. The 2- and 3-glyceroyl esters were found to be 'energy-rich' with GFEC values of -9.1 kcal/mol and -7.8 kcal/mol, respectively. This result indicates that the analogous 2- and 3-glyceroyl esters of polyglyceric acid are also energy-rich and, therefore, could have acted as an energy source for primitive phosphoanhydride synthesis.

  17. Fumaric acid esters in psoriasis and multiple sclerosis.

    PubMed

    Zecca, C; Caporro, M; Adami, M; Mainetti, C; Gobbi, C

    2014-06-01

    Fumaric acid esters (FAEs) are effective in patients with moderate to severe psoriasis. Recent studies also report the efficacy of one FAE component, dimethylfumarate, in relapsing forms of multiple sclerosis (MS). We describe the case of a patient with MS who developed severe plaque psoriasis during interferon-?-1a treatment for MS. The psoriasis was unresponsive to usual topical treatments and phototherapy. The patient was started on FAE 720 mg daily, with complete remission of the psoriatic lesions and neurological stabilization at follow-up at 24 months. Our case suggests that FAEs could represent a therapeutic option for patients with MS who develop plaque psoriasis following exposure to immune-modulating agents. PMID:24779791

  18. Effects of phthalic acid esters on the liver and thyroid

    SciTech Connect

    Hinton, R.H.; Mitchell, F.E.; Mann, A.; Chescoe, D.; Price, S.C.; Nunn, A.; Grasso, P.; Bridges, J.W.

    1986-12-01

    The effects, over periods from 3 days to 9 months of administration, of diets containing di-2-ethylhexyl phthalate are very similar to those observed in rats administered diets containing hypolipidemic drugs such as clofibrate. Changes occur in a characteristic order commencing with alterations in the distribution of lipid within the liver, quickly followed by proliferation of hepatic peroxisomes and induction of the specialized P-450 isoenzyme(s) catalyzing omega oxidation of fatty acids. There follows a phase of mild liver damage indicated by changes in incorporation of /sup 3/H-thymidine into DNA, by induction of glucose-6-phosphatase activity and a loss of glycogen, eventually leading to the formation of enlarged lysosomes through autophagy and the accumulation of lipofuscin. Associated changes are found in the kidney and thyroid. The renal changes are limited to the proximal convoluted tubules and are generally similar to changes found in the liver. The effects on the thyroid are more marked. Although the levels of thyroxine in plasma fall to about half normal values, serum triiodothyronine remains close to normal values while the appearance of the thyroid varies, very marked hyperactivity being noted 7 days after commencement of treatment, this is less marked at 14 days, but even after 9 months treatment there is clear cut evidence for hyperactivity with colloid changes which indicate this has persisted for some time. The short-term in vivo hepatic effects of the three phthalate esters can be reproduced in hepatocytes in tissue culture. All three phthalate esters, as well as clofibrate, have early marked effects on the metabolism of fatty acids in isolated hepatocytes. A hypothesis is presented to explain the progress from these initial metabolic effects to the final formation of liver tumors.

  19. 75 FR 20785 - Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the Requirement of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ...Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the Requirement of a Tolerance...polyglyceryl phthalate ester of coconut oil fatty acids; exemption from the requirement of a tolerance...polyglyceryl phthalate ester of coconut oil fatty acids'' pursuant to a petition by the...

  20. 75 FR 4292 - 2-Propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene and 2-methylpropyl 2-methyl-2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ...EPA-HQ-OPP-2009-0699; FRL- 8807-4] 2-Propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene...tolerance for residues of 2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene...permissible level for residues of 2-propenoic acid, 2-ethylhexyl ester, polymer with...

  1. A Calculation of Spatial Range of Colloidal Silicic Acid Deposited Downstream from the Alkali Front

    NASA Astrophysics Data System (ADS)

    Niibori, Yuichi; Iijima, Kazuki; Tamura, Naoyuki; Mimura, Hitoshi

    A high alkali domain spreads out due to the use of cement materials for the construction of the repository of radioactive wastes. Sudden change of pH at this alkali front produces colloidal silicic acid (polymeric silicic acid) in addition to the deposition of supersaturated monomeric silicic acid onto the fracture surface of flow-pathway. The colloidal silicic acid also deposits with relatively small rate-constant in the co-presence of solid phase. Once the flow-path surface is covered with the amorphous silica, the surface seriously degrades the sorption behavior of radionuclides (RNs). Therefore, so far, the authors have examined the deposition rates of supersaturated silicic acid. This study summarized the deposition rate-constants defined by the first-order reaction equation under various conditions of co-presence of amorphous silica powder. Then, using the smallest rate-constant (1.0×10-12 m/s in the co-presence of calcium ions of 1 mM) and a simulation code, COLFRAC-MRL, the spatial range of colloidal silicic acid deposited downstream from the alkali front was estimated. The results suggested the clogging caused by the deposition of colloidal silicic acid in flow-path. The altered spatial range in the flow-path was limited to around 30 m in fracture and to several centimeters in rock matrix.

  2. Calculation of 29Si NMR shifts of silicate complexes with carbohydrates, amino acids, and muhicarboxylic acids: potential role in biological silica utilization

    NASA Astrophysics Data System (ADS)

    Sahai, Nita

    2004-01-01

    The existence of ether or ester-like complexes of silicate with organic compounds has long been debated in the literature on biological utilization of silicon. Comparison of theoretically calculated 29Si NMR chemical shifts for such complexes with experimentally measured values in biological systems could provide a diagnostic tool for identifying which, if any of these molecules exist under physiological conditions. Results are presented here for ab initio molecular orbital calculations of 29Si NMR shifts and formation energies of silicate complexes with polyalcohols, sugar-acids, pyranose sugars, amino acids and multicarboxylic acids. The effects of functional group and molecular structure including ligand size, denticity, ring size, silicon polymerization and coordination number on calculated 29Si shifts were considered. The potential role of such compounds in biological silica utilization pathways is discussed. 29Si NMR shifts and energies were calculated at the HF/6-311+G(2d,p)//HF/6-31G* level. The main result is that only five-membered rings containing penta- and hexa-coordinated Si can explain experimentally observed resonances at ˜ -101 and -141 ppm. Further, the heptet observed in 1H- 29Si coupled spectra can only be explained by structures where Si bonds to oxygens atoms in H-C-O-Si linkages with six symmetrically equivalent H atoms. While compounds containing quadra-coordinated silicon may exist in intracellular silicon storage pools within diatoms, calculated reaction energies suggest that the organism has no thermodynamic advantage in taking up extracellular organ-silicate compounds, instead of silicic acid, from the ambient aqueous environment. Hyper-coordinated complexes are deemed unlikely for transport and storage, though they may exist as transient reactive intermediates or activated complexes during enzymatically- catalyzed silica polymerization, as known previously from sol-gel silica synthesis studies.

  3. Methyl esters from vegetable oils with hydroxy fatty acids: Comparison of lesquerella and castor methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The search for alternative feedstocks for biodiesel as partial replacement for petrodiesel has recently extended to castor oil. In this work, the castor oil methyl esters were prepared and their properties determined in comparison to the methyl esters of lesquerella oil, which in turn is seen as alt...

  4. Synthesis and cytotoxic activity of derivatives of 6 Z -acetylmethylenepenicillanic acid tert -butyl ester

    Microsoft Academic Search

    M. Vorona; I. Potorochina; G. Veinberg; S. Belyakov; I. Shestakova; I. Kanepe; E. Lukevics

    2009-01-01

    The sulfoxide of 6Z-[2-(methoxyimino)propylidene]penicillanic acid tert-butyl ester and the sulfones of 6Z-[2-(hydroxyimino-, methoxyimino-, benzyloxyimino-, 2-bromo- and 4-bromobenzyloxyimino)-propylidene]penicillanic acid in the\\u000a syn and anti forms have been synthesized by the condensation of the sulfoxide and sulfone of 6Z-acetylmethylenepenicillanic acid tert-butyl ester with hydroxylamine, methoxyamine, benzyloxyamine, 2-bromo- and 4-bromobenzyloxyamines. The syn and anti isomers\\u000a of 3Z-(2-methoxyiminopropylidene)-4R-(benzothiazolyl-2-dithio)-2-oxoazetidinyl-1R-(2-propenyl)acetic acid tert-butyl ester were obtained by

  5. Lewis acid promoted ruthenium(II)-catalyzed etherifications by selective hydrogenation of carboxylic acids/esters.

    PubMed

    Li, Yuehui; Topf, Christoph; Cui, Xinjiang; Junge, Kathrin; Beller, Matthias

    2015-04-20

    Ethers are of fundamental importance in organic chemistry and they are an integral part of valuable flavors, fragrances, and numerous bioactive compounds. In general, the reduction of esters constitutes the most straightforward preparation of ethers. Unfortunately, this transformation requires large amounts of metal hydrides. Presented herein is a bifunctional catalyst system, consisting of Ru/phosphine complex and aluminum triflate, which allows selective synthesis of ethers by hydrogenation of esters or carboxylic acids. Different lactones were reduced in good yields to the desired products. Even challenging aromatic and aliphatic esters were reduced to the desired products. Notably, the in?situ formed catalyst can be reused several times without any significant loss of activity. PMID:25728921

  6. Orthogonal Fatty Acid Biosynthetic Pathway Improves Fatty Acid Ethyl Ester Production in Saccharomyces cerevisiae.

    PubMed

    Eriksen, Dawn T; HamediRad, Mohammad; Yuan, Yongbo; Zhao, Huimin

    2015-07-17

    Fatty acid ethyl esters (FAEEs) are a form of biodiesel that can be microbially produced via a transesterification reaction of fatty acids with ethanol. The titer of microbially produced FAEEs can be greatly reduced by unbalanced metabolism and an insufficient supply of fatty acids, resulting in a commercially inviable process. Here, we report on a pathway engineering strategy in Saccharomyces cerevisiae for enhancing the titer of microbially produced FAEEs by providing the cells with an orthogonal route for fatty acid synthesis. The fatty acids generated from this heterologous pathway would supply the FAEE production, safeguarding endogenous fatty acids for cellular metabolism and growth. We investigated the heterologous expression of a Type-I fatty acid synthase (FAS) from Brevibacterium ammoniagenes coupled with WS/DGAT, the wax ester synthase/acyl-coenzyme that catalyzes the transesterification reaction with ethanol. Strains harboring the orthologous fatty acid synthesis yielded a 6.3-fold increase in FAEE titer compared to strains without the heterologous FAS. Variations in fatty acid chain length and degree of saturation can affect the quality of the biodiesel; therefore, we also investigated the diversity of the fatty acid production profile of FAS enzymes from other Actinomyces organisms. PMID:25594225

  7. The content and composition of sterols and sterol esters in low erucic acid rapeseed ( Brassica napus )

    Microsoft Academic Search

    Anna Johansson; Lars-Åke Appelqvist

    1978-01-01

    The low temperature crystallization technique for the enrichment of “minor” components, such as sterols and sterol esters,\\u000a from vegetable oils was applied to low erucic acid rapeseed oils. The recovery of free sterols and sterol esters was estimated\\u000a by use of14C-cholesterol and14C-cholesterol oleate. 80% of the free sterols and 45% of the sterol esters were recovered in the liquid fraction,

  8. The effects of solvent mixtures on the gel permeation chromatography of alkanes, fatty acids, and fatty acid esters

    E-print Network

    Bolton, Patrick Lee

    1985-01-01

    MATERIALS AND METHODS Procedures In this research, the effects of binary solvent mixtures on the gel permeation chromatographic separation of homologous series of model compounds- fatty acids, n-alkanes, methyl fatty acid esters, and butyl fatty acid.... Slowly add 1 mL conc. sulfuric acid, swirling gently. 3. Reflux for 1 hr. and let cool. 4. pour into a 125 mL separatory funnel containing 20 mL cold 15 water (25 mL for the butyl esters). 5. Extract with 20 mL (25 mL for the butyl esters) diethyl...

  9. Fukiic and piscidic acid esters from the rhizome of Cimicifuga racemosa and the in vitro estrogenic activity of fukinolic acid.

    PubMed

    Kruse, S O; Löhning, A; Pauli, G F; Winterhoff, H; Nahrstedt, A

    1999-12-01

    Hydroxycinnamic acid esters of fukiic acid and piscidic acid were isolated from a 50% ethanolic extract obtained from the rhizomes of Cimicifuga racemosa (Ranunculaceae). Besides 2-E-caffeoylfukiic acid (fukinolic acid), 2-E-feruloylfukiic acid (cimicifugic acid A), 2-E-isoferuloylfukiic acid (cimicifugic acid B), 2-E-feruloylpiscidic acid (cimicifugic acid E) and 2-E-isoferuloylpiscidic acid (cimicifugic acid F), free caffeic, ferulic and isoferulic acids were isolated. The estrogenic activity of fukinolic acid was shown by increased proliferation (126% at 5 x 10(-8) M) of an estrogen dependent MCF-7 cell system with reference to estradiol (120% at 10(-10) M). PMID:10630125

  10. An Investigation of Ester Group Steric Effects on Metal Ion Extraction by Symmetrically Substituted Methylenediphosphonic Acids

    Microsoft Academic Search

    D. C. Stepinski; D. R. McAlister; P. R. Zalupski; R. Chiarizia; A. W. Herlinger

    2004-01-01

    Symmetrically substituted partial alkyl?esters of methylenediphosphonic acid are powerful metal ion extractants for actinides in all oxidation states. A preliminary study of calcium and americium(III) extraction by the n?octyl and 2?ethylhexyl di?substituted esters of methylenediphosphonic acid revealed the distribution ratios and the nitric acid dependency behaviors for the two extractants to be very similar, with the extraction efficiency for the

  11. Cinnamyl alcohols and methyl esters of fatty acids from Wedelia prostrata callus cultures.

    PubMed

    El-Mawla, Ahmed M A Abd; Farag, Salwa F; Beuerle, Till

    2011-01-01

    Two methyl esters of fatty acids, namely octadecanoic acid methyl ester (methyl stearate) and hexadecanoic acid methyl ester (methyl palmitate), in addition to four cinnamyl alcohol derivatives, sinapyl alcohol, coniferyl alcohol, p-coumaryl alcohol and coniferyl alcohol 4-O-glucoside (coniferin), were isolated from callus cultures of Wedelia prostrata. The structure of coniferin was established by spectroscopic and chemical methods, while the other compounds were identified by gas chromatography-mass spectrometry and thin layer chromatography in comparison with standards. PMID:21240761

  12. The effect of benzoic acid or its ethyl ester on rumen fermentation parameters

    E-print Network

    Paris-Sud XI, Université de

    The effect of benzoic acid or its ethyl ester on rumen fermentation parameters J Nousiainen Valio response of BA or its ethyl ester (EB) on the rumen fermentation parameters in the continuous culture to represent the maximum amount in vivo. The fermentation apparatus and the design of trials as well

  13. Labelling fatty acids by exposure to tritium gas. I. Saturated methyl esters

    Microsoft Academic Search

    R. F. Nystrom; L. H. Mason; E. P. Jones; H. J. Dutton

    1959-01-01

    Summary Seeds of the tree Zellcova serrata, family Ulmaceae, were found to contain 21.7% of glyeeride oil having iodine value 12.9, saponification value 292, and glycerol yield 13.6%. The oil was converted to methyl esters and examined by gas chromatography, followed by fractional distillation of the esters and identification of the individual acids. The percentage eomposi

  14. Carbodithioic acid esters of fluoxetine, a novel class of dual-function spermicides.

    PubMed

    Kiran Kumar, S T V S; Kumar, Lalit; Sharma, Vishnu L; Jain, Ashish; Jain, Rajeev K; Maikhuri, Jagdamba P; Kumar, Manish; Shukla, Praveen K; Gupta, Gopal

    2008-10-01

    Carbodithioic acid esters of fluoxetine have been prepared by replacing the methylamino function in aminopropane chain with carbodithioic acid ester group and by adding various S-2-hydroxypropyl ester of dialkyl carbodithioic acid at 3-methylamino group. Some of these compounds showed spermicidal, antifungal and anti-Trichomonas activities. The study revealed that incorporation of carbodithioic acid residue directly into fluoxetine structure leads to compounds with better antifungal and anti-Trichomonas activities, and N-methyl-[3-phenyl-3-(4-trifluoromethyl-phenoxy)-propyl]carbodithioic acid S-(2-pyrrolidino-ethyl) ester (14) has shown better profile than both fluoxetine and nonoxynol-9. Further lead optimization may yield a potent dual-function spermicide. PMID:18061311

  15. Preparation and characterization of fatty acid ester\\/building material composites for thermal energy storage in buildings

    Microsoft Academic Search

    Ali Karaipekli; Ahmet Sar?

    2011-01-01

    In this study, fatty acid ester\\/building material composites as novel form-stable phase change materials (PCMs) were prepared by absorbing liquid fatty acid esters into porous network of conventional building materials. In the composite erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) esters were used as PCM for thermal energy storage, and cement and gypsum used as supporting material. The composite PCMs

  16. ENZYMATIC SYNTHESIS OF A GALACTOPYRANOSE SOPHOROLIPID FATTY ACID-ESTER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A C18:1 sophorolipid lactone produced by the yeast Candida bombicola was deacetylated and ring opened with sodium methoxide to the methyl ester form. After re-acetylation with vinyl acetate using an immobilized lipase, the methyl ester was transesterified with 1,2-3,4-di-O-isopropylidene-D-galactop...

  17. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...fatty acid esters of glycerol and propylene glycol may be safely used in food in...reacting edible fats or oils with propylene glycol. (b) The additive meets...produce the intended physical effect as an emulsifier,...

  18. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...fatty acid esters of glycerol and propylene glycol may be safely used in food in...reacting edible fats or oils with propylene glycol. (b) The additive meets...produce the intended physical effect as an emulsifier,...

  19. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...fatty acid esters of glycerol and propylene glycol may be safely used in food in...reacting edible fats or oils with propylene glycol. (b) The additive meets...produce the intended physical effect as an emulsifier,...

  20. Direct Determination of MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Vegetable Oils by LC–TOFMS

    PubMed Central

    Haines, Troy D.; Adlaf, Kevin J.; Pierceall, Robert M.; Lee, Inmok; Venkitasubramanian, Padmesh

    2010-01-01

    Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LC–TOFMS method were compared with the DGF method. The DGF method consistently gave results that were greater than the LC–TOFMS method. The levels of MCPD esters and glycidyl esters found in a variety of vegetable oils are reported. MCPD monoesters were not found in any oil samples. MCPD diesters were found only in samples containing palm oil, and were not present in all palm oil samples. Glycidyl esters were found in a wide variety of oils. Some processing conditions that influence the concentration of MCPD esters and glycidyl esters are discussed. PMID:21350591

  1. Fatty acid alkyl esters: perspectives for production of alternative biofuels.

    PubMed

    Röttig, Annika; Wenning, Leonie; Bröker, Daniel; Steinbüchel, Alexander

    2010-02-01

    The global economy heads for a severe energy crisis: whereas the energy demand is going to rise, easily accessible sources of crude oil are expected to be depleted in only 10-20 years. Since a serious decline of oil supply and an associated collapse of the economy might be reality very soon, alternative energies and also biofuels that replace fossil fuels must be established. In addition, these alternatives should not further impair the environment and climate. About 90% of the biofuel market is currently captured by bioethanol and biodiesel. Biodiesel is composed of fatty acid alkyl esters (FAAE) and can be synthesized by chemical, enzymatic, or in vivo catalysis mainly from renewable resources. Biodiesel is already established as it is compatible with the existing fuel infrastructure, non-toxic, and has superior combustion characteristics than fossil diesel; and in 2008, the global production was 12.2 million tons. The biotechnological production of FAAE from low cost and abundant feedstocks like biomass will enable an appreciable substitution of petroleum diesel. To overcome high costs for immobilized enzymes, the in vivo synthesis of FAAE using bacteria represents a promising approach. This article points to the potential of different FAAE as alternative biofuels, e.g., by comparing their fuel properties. In addition to conventional production processes, this review presents natural and genetically engineered biological systems capable of in vivo FAAE synthesis. PMID:20033403

  2. Premixed ignition behavior of C{sub 9} fatty acid esters: A motored engine study

    SciTech Connect

    Zhang, Yu.; Yang, Yi; Boehman, Andre L. [EMS Energy Institute, The Pennsylvania State University, University Park, PA 16802 (United States)

    2009-06-15

    An experimental study on the premixed ignition behavior of C{sub 9} fatty acid esters has been conducted in a motored CFR engine. For each test fuel, the engine compression ratio was gradually increased from the lowest point (4.43) to the point where significant high temperature heat release (HTHR) was observed. The engine exhaust was sampled and analyzed through GC-FID/TCD and GC-MS. Combustion analysis showed that the four C{sub 9} fatty acid esters tested in this study exhibited evidently different ignition behavior. The magnitude of low temperature heat release (LTHR) follows the order, ethyl nonanoate > methyl nonanoate >> methyl 2-nonenoate > methyl 3-nonenoate. The lower oxidation reactivity for the unsaturated fatty acid esters in the low temperature regime can be explained by the reduced amount of six- or seven-membered transition state rings formed during the oxidation of the unsaturated esters due to the presence of a double bond in the aliphatic chain of the esters. The inhibition effect of the double bond on the low temperature oxidation reactivity of fatty acid esters becomes more pronounced as the double bond moves toward the central position of the aliphatic chain. GC-MS analysis of exhaust condensate collected under the engine conditions where only LTHR occurred showed that the alkyl chain of the saturated fatty acid esters participated in typical paraffin-like low temperature oxidation sequences. In contrast, for unsaturated fatty acid esters, the autoignition can undergo olefin ignition pathways. For all test compounds, the ester functional group remains largely intact during the early stage of oxidation. (author)

  3. Synthesis of an acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    DOEpatents

    Moens, Luc (Lakewood, CO)

    1999-01-01

    A process of preparing an acid addition salt of delta-aminolevulinic acid comprising: dissolving a lower alkyl 5-bromolevulinate and an alkali metal diformylamide in an organic solvent selected from the group consisting of acetonitrile, methanol, tetrahydrofuran, 2-methyltetrahydrofuran and methylformate or mixtures thereof to form a suspension of an alkyl 5-(N,N-diformylamino) levulinate ester; and hydrolyzing said alkyl 5-(N,N-diformylamino) levulinate with an inorganic acid to form an acid addition salt of delta-amino levulinic acid.

  4. Effects of 2,4-dichlorophenoxyacetic acid butyl ester on chick liver

    Microsoft Academic Search

    Ana María Evangelista de Duffard; Adriana Fabra de Peretti; Stella Castro de Cantarini; Ricardo Duffard

    1993-01-01

    Fertilized hen eggs were externally treated with 3.1 mg 2,4-dichlorophenoxyacetic acid butyl ester (2,4-D ester) before starting incubation. Liver lipid composition, (14C)2,4-dichlorophenoxyacetic acid (14C-2,4-D) subcellular distribution and covalent binding to proteins and lipids of chicks hatched from these eggs were studied. Furthermore, catalase, glutathione S-transferase and glucose 6-phosphatase activities as well as reduced glutathione content were determined. The herbicide produced

  5. Anti-inflammatory\\/anti-pyretic salicylic acid esters with low gastric ulcerogenic activity

    Microsoft Academic Search

    K. D. Rainsford; M. W. Whitehouse

    1980-01-01

    The methyl and some other esters of acetylsalicylic and salicylic acids and their derivatives were found to have much lower gastric ulcerogenic activity (when assayed in the stress-sensitized rat) compared with their corresponding acids. There was little or no loss in therapeutic potencies of these salicylate esters as determined by assessment of anti-inflammatory activity (against the carrageenan-induced oedema) and antipyretic

  6. Flame-ionization detector response to methyl, ethyl, propyl, and butyl esters of fatty acids

    Microsoft Academic Search

    Franz Ulberth; Robert G. Gabernig; Franz Schrammel

    1999-01-01

    The concept of theoretical response factors is not directly applicable to methyl esters of short-chain fatty acids (FA), since\\u000a their carbon deficiency is larger than expected from theory. Substituting the methyl group by an ethyl, propyl, or butyl group\\u000a improved the flame-ionization efficiency of fatty acid esters gradually, up to the point where the empirical response factors\\u000a of the butyl

  7. The Metabolism of 3-Indolylalkanecarboxylic Acids, and their Amides, Nitriles and Methyl Esters in Plant Tissues

    Microsoft Academic Search

    C. H. Fawcett; R. L. Wain; F. Wightman

    1960-01-01

    Plant growth-regulating activity in homologous series of omega -(3-indolyl)alkanecarboxylic acids, their methyl esters, amides and nitriles has been assessed in the wheat-cylinder, pea-curvature and pea-segment tests. In wheat tissue all homologues were active except 3-indolecarboxylic acid and its corresponding ester, amide and nitrile. These compounds, together with the propio-, butyro-, valero- and capro-nitriles, were inactive in the pea tests. The

  8. Analysis of the dark-colored impurities in sulfonated fatty acid methyl ester

    Microsoft Academic Search

    Kaoru Yamada; Shigeaki Matsutani

    1996-01-01

    A fractionally distilled C14?C16 fatty acid methyl ester, derived from palm oil, was sulfonated with gaseous SO3 in a falling film reactor to form an ?-sulfo fatty acid methyl ester (?-SF; unbleached and unneutralized form). The included\\u000a dark-colored impurities were then separated from ?-SF as a diethyl ether-insoluble matter. After purification by thin-layer\\u000a chromatography, the colored species were analyzed by

  9. Protocatechuic acid alkyl esters: hydrophobicity as a determinant factor for inhibition of NADPH oxidase.

    PubMed

    de Faria, C M Q G; Nazaré, A C; Petrônio, M S; Paracatu, L C; Zeraik, M L; Regasini, L O; Silva, D H S; da Fonseca, L M; Ximenes, V F

    2012-01-01

    This study presents the increased efficiency of NADPH oxidase inhibition produced by esterification of protocatechuic acid (P0). Alkyl esters bearing chain lengths of 4 (P4), 7 (P7) and 10 (P10) carbons were synthesized and their oxidation potential, hydrophobicity, antiradical activity, inhibition of superoxide anion (O2°(-)), and the abilities to affect hypochlorous acid (HOCl) production by leukocytes and inhibit myeloperoxidase (MPO) chlorinating activity were studied. The increased hydrophobicity (logP, 0.81-4.82) of the esters was not correlated with a significant alteration in their oxidation potential (0.222-0.298 V). However, except for P10, the esters were ~ 2-fold more effective than the acid precursor for the scavenging of DPPH and peroxyl radicals. The esters were strong inhibitors of O2°(-) released by activated neutrophils (PMNs) and peripheral blood mononuclear cells (PBMCs). A correlation was found between the carbon chain length and the relative inhibitory potency. P7, the most active ester, was ~ 10-fold more efficient as NADPH oxidase inhibitor than apocynin. The esters strongly inhibited the release of HOCl by PMNs, which was a consequence of the inhibition of NADPH oxidase activity in these cells. In conclusion, as effective inhibitors of NADPH oxidase, the esters of protocatechuic acid are promising drugs for treatment of chronic inflammatory diseases. Moreover, this is the first demonstration that, besides the redox active moiety, the hydrophobicity can also be a determinant factor for the design of NADPH oxidase inhibitors. PMID:22934778

  10. Novel fatty acid esters of p-coumaryl alcohol in epicuticular wax of apple fruit.

    PubMed

    Whitaker, B D; Schmidt, W F; Kirk, M C; Barnes, S

    2001-08-01

    Hexane extracts of epicuticular wax from cv. Gala apples were noted to have an unusual, broad absorbance maximum at approximately 258 nm, which led us to isolate and identify the primary UV-absorbing compounds. Column and thin-layer chromatography yielded a fraction that gave a series of paired, 260-nm-absorbing peaks on C(18) HPLC. These were shown to be a family of phenolic fatty acid esters, for which retention times increased with increasing fatty acid chain length, and paired peaks were esters of two related phenolics with the same fatty acid moiety. Alkaline hydrolysis of the esters released two water-soluble phenolics separable by C(18) HPLC. Electrospray ionization mass spectrometry gave a molecular mass of 150 for both, and (1)H NMR plus UV absorbance spectra identified them as E and Z isomers of p-coumaryl alcohol. Alkaline cleavage of the fatty acid esters in the presence of methanol or ethanol resulted in partial derivatization of E-p-coumaryl alcohol to the corresponding gamma-O-methyl or O-ethyl ether. Gradient HMQC NMR of the HPLC-purified stearate ester of E-p-coumaryl alcohol indicated that fatty acid esterification occurs at the gamma-OH rather than at the 4-OH on the phenyl ring. This is the first report of fatty acid esters of monolignols as a natural plant product. PMID:11513667

  11. Fatty Acid Phytyl Ester Synthesis in Chloroplasts of Arabidopsis[W

    PubMed Central

    Lippold, Felix; vom Dorp, Katharina; Abraham, Marion; Hölzl, Georg; Wewer, Vera; Yilmaz, Jenny Lindberg; Lager, Ida; Montandon, Cyrille; Besagni, Céline; Kessler, Felix; Stymne, Sten; Dörmann, Peter

    2012-01-01

    During stress or senescence, thylakoid membranes in chloroplasts are disintegrated, and chlorophyll and galactolipid are broken down, resulting in the accumulation of toxic intermediates, i.e., tetrapyrroles, free phytol, and free fatty acids. Chlorophyll degradation has been studied in detail, but the catabolic pathways for phytol and fatty acids remain unclear. A large proportion of phytol and fatty acids is converted into fatty acid phytyl esters and triacylglycerol during stress or senescence in chloroplasts. We isolated two genes (PHYTYL ESTER SYNTHASE1 [PES1] and PES2) of the esterase/lipase/thioesterase family of acyltransferases from Arabidopsis thaliana that are involved in fatty acid phytyl ester synthesis in chloroplasts. The two proteins are highly expressed during senescence and nitrogen deprivation. Heterologous expression in yeast revealed that PES1 and PES2 have phytyl ester synthesis and diacylglycerol acyltransferase activities. The enzymes show broad substrate specificities and can employ acyl-CoAs, acyl carrier proteins, and galactolipids as acyl donors. Double mutant plants (pes1 pes2) grow normally but show reduced phytyl ester and triacylglycerol accumulation. These results demonstrate that PES1 and PES2 are involved in the deposition of free phytol and free fatty acids in the form of phytyl esters in chloroplasts, a process involved in maintaining the integrity of the photosynthetic membrane during abiotic stress and senescence. PMID:22623494

  12. Caffeic acid phenethyl ester modulates methotrexate-induced oxidative stress in testes of rat.

    PubMed

    Armagan, A; Uzar, E; Uz, E; Yilmaz, H R; Kutluhan, S; Koyuncuoglu, H R; Soyupek, S; Cam, H; Serel, T A

    2008-07-01

    The aim of this study was to investigate the possible protective role of caffeic acid phenethyl ester on testicular toxicity of methotrexate in rats. Nineteen male rats were divided into three groups as follows: group I, control; group II, methotrexate-treated; group III, methotrexate + caffeic acid phenethyl ester-treated. In the second day of experiment, a single dose of methotrexate was intraperitoneally administered to groups II and III, although a daily single dose of caffeic acid phenethyl ester was intraperitoneally administered to group III for 7 days. At the end of the experiment, the testes of the animals were removed and weighed. In the tissue, the level of lipid peroxidation as malondialdehyde and activities of superoxide dismutase were higher in the methotrexate group than in the control group. Lipid peroxidation levels and superoxide dismutase activities were decreased in caffeic acid phenethyl ester + methotrexate group compared with methotrexate group. The activities of catalase in the methotrexate group decreased insignificantly although its activities were significantly increased by caffeic acid phenethyl ester administration. The activity of glutathione peroxidase did not change in the groups. There was significant difference in body weight between control and methotrexate-induced groups. In conclusion, the administration of methotrexate causes elevation of oxidative stress although treatment with caffeic acid phenethyl ester has protective effects on the oxidative stress in testes. PMID:18829730

  13. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F.; He, K.; Ma, Y.; Rahn, K. A.; Zhang, Q.

    2015-03-01

    We have developed an enhanced analytical procedure to measure organic acids and methyl esters in fine aerosol with much greater specificity and sensitivity than previously available. This capability is important because of these species and their low concentrations, even in highly polluted atmospheres like Beijing, China. The procedure first separates the acids and esters from the other organic compounds with anion-exchange solid- phase extraction (SPE), then, quantifies them by gas chromatography coupled with mass spectrometry. This allows us to accurately quantify the C4-C11 dicarboxylic and the C8-C30 monocarboxylic acids. Then the acids are separated from the esters on an aminopropyl SPE cartridge, whose weak retention isolates and enriches the acids from esters prevents the fatty acids and dimethyl phthalate from being overestimated. The resulting correlations between the aliphatic acids and fatty acid methyl esters (FAMEs) suggest that FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. In all, 17 aromatic acids were identified and quantified using this procedure coupled with gas chromatography-tandem mass spectrometry, including the five polycyclic aromatic hydrocarbon (PAH) acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH-acids and the dicarboxylic and aromatic acids indicated that the first three acids and 1,8-naphthalic anhydride were mainly secondary, the last two mainly primary.

  14. 40 CFR 721.9965 - Fatty acids, C10-13 - branched, vinyl esters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Fatty acids, C10-13 - branched, vinyl esters...Chemical Substances § 721.9965 Fatty acids, C10- 13 - branched, vinyl...chemical substance identified as fatty acids, C10-13 - branched,...

  15. 40 CFR 721.9965 - Fatty acids, C10-13 - branched, vinyl esters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Fatty acids, C10-13 - branched, vinyl esters...Chemical Substances § 721.9965 Fatty acids, C10- 13 - branched, vinyl...chemical substance identified as fatty acids, C10-13 - branched,...

  16. Inactive Methyl Indole-3-Acetic Acid Ester Can Be Hydrolyzed and Activated by Several Esterases Belonging

    E-print Network

    Pichersky, Eran

    Inactive Methyl Indole-3-Acetic Acid Ester Can Be Hydrolyzed and Activated by Several Esterases (salicylic acid binding protein 2) hydrolyzes methyl salicylate to salicylic acid. There are 20 homologs candidate MeIAA esterases that could hydrolyze MeIAA. MeIAA, like IAA, exerts inhibitory activity

  17. 40 CFR 721.10452 - 9-Octadecenoic acid (9Z)-, 1,1?-(dimethylstannylene) ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false 9-Octadecenoic acid (9Z...Chemical Substances § 721.10452 9-Octadecenoic acid (9Z...chemical substance identified as 9-octadecenoic acid (9Z...dimethylstannylene) ester (PMN P-02-659; CAS No. 3865-34-7) is...

  18. 40 CFR 721.10452 - 9-Octadecenoic acid (9Z)-, 1,1?-(dimethylstannylene) ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false 9-Octadecenoic acid (9Z...Chemical Substances § 721.10452 9-Octadecenoic acid (9Z...chemical substance identified as 9-octadecenoic acid (9Z...dimethylstannylene) ester (PMN P-02-659; CAS No. 3865-34-7) is...

  19. Impact of esters of mono- and dicarboxylic acids on diesel fuel quality

    SciTech Connect

    Serdari, A.; Lois, E.; Stournas, S. [National Technical Univ. of Athens (Greece)] [National Technical Univ. of Athens (Greece)

    1999-09-01

    The objective of this work was to assess how esters of mono- and dicarboxylic acids of different structure affect diesel fuel quality, by measuring cetane numbers and cold flow properties of blends of the esters under investigation with gasoil. An increase in either the chain length of the normal alcohol used for the esterification or the chain length of the mono- or dicarboxylic acid involved in the esterification improves the cetane number. Among the fatty acid esters of the same molecular type, those having the carboxylic group close to one end of the molecule have better ignition quality, whereas those having the ester group around the middle of the molecule appear to have better cold flow performance. Oleates combine good ignition quality with adequate cold flow performance, whereas the high oxygen content of some diesters seems to be an extra advantage.

  20. Sugar fatty acid ester surfactants: Structure and ultimate aerobic biodegradability

    Microsoft Academic Search

    Irene J. A. Baker; Barry Matthews; Hector Suares; Irena Krodkiewska; D. Neil Furlong; Franz Grieser; Calum I. Drummond

    2000-01-01

    Ultimate aerobic biodegradabilities of an array of sugar ester surfactants were determined by International Standards Organisation\\u000a method 7827, “Water Quality—Evaluation in an Aqueous Medium of the Aerobic Biodegradability of Organic Compounds, Method by\\u000a Dissolved Organic Carbon” (1984). The surfactants were nonionic sugar esters with different-sized sugar head groups (formed\\u000a from glucose, sucrose, or raffinose) and different lengths and numbers of

  1. Kinematic viscosity of fatty acid methyl esters: Prediction, calculated viscosity contribution of esters with unavailable data, and carbon-oxygen equivalents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many properties of biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing feedstocks, are largely determined by its major components, the fatty acid alkyl esters. Therefore, information on the properties of individual components and their interaction is ...

  2. Polymers from amino acids: development of dual ester-urethane melt condensation approach and mechanistic aspects.

    PubMed

    Anantharaj, S; Jayakannan, M

    2012-08-13

    A new dual ester-urethane melt condensation methodology for biological monomers-amino acids was developed to synthesize new classes of thermoplastic polymers under eco-friendly and solvent-free polymerization approach. Naturally abundant L-amino acids were converted into dual functional ester-urethane monomers by tailor-made synthetic approach. Direct polycondensation of these amino acid monomers with commercial diols under melt condition produced high molecular weight poly(ester-urethane)s. The occurrence of the dual ester-urethane process and the structure of the new poly(ester-urethane)s were confirmed by (1)H and (13)C NMR. The new dual ester-urethane condensation approach was demonstrated for variety of amino acids: glycine, ?-alanine, L-alanine, L-leucine, L-valine, and L-phenylalanine. MALDI-TOF-MS end group analysis confirmed that the amino acid monomers were thermally stable under the melt polymerization condition. The mechanism of melt process and the kinetics of the polycondensation were studied by model reactions and it was found that the amino acid monomer was very special in the sense that their ester and urethane functionality could be selectively reacted by polymerization temperature or catalyst. The new polymers were self-organized as ?-sheet in aqueous or organic solvents and their thermal properties such as glass transition temperature and crystallinity could be readily varied using different l-amino acid monomers or diols in the feed. Thus, the current investigation opens up new platform of research activates for making thermally stable and renewable engineering thermoplastics from natural resource amino acids. PMID:22713137

  3. Organic Base?Catalyzed Stereoselective Isomerizations of 4?Hydroxy?4?phenyl?but?2?ynoic Acid Methyl Ester to (E)? and (Z)?4?Oxo?4?phenyl?but?2?enoic Acid Methyl Esters

    Microsoft Academic Search

    John P. Sonye; Kazunori Koide

    2006-01-01

    We have developed a 1,4?diazabicyclo[2.2.2]octane (DABCO)?catalyzed isomerization of 4?hydroxy?4?phenyl?but?2?ynoic acid methyl ester to (E)?4?oxo?4?phenyl?but?2?enoic acid methyl ester and an N,N?diisopropylethylamine?catalyzed isomerization of the same substrate to (Z)?4?oxo?4?phenyl?but?2?enoic acid methyl ester.

  4. Competition between selenium (IV) and silicic acid on the hematite surface.

    PubMed

    Jordan, Norbert; Marmier, Nicolas; Lomenech, Claire; Giffaut, Eric; Ehrhardt, Jean-Jacques

    2009-03-01

    Competition between selenium (IV) and silicic acid for the hematite (alpha-Fe(2)O(3)) surface has been studied during this work. Single batch experiments have been performed to study separately the sorption of selenium (IV) and silicic acid as a function of the pH. With the help of the 2-pK surface complexation model, experimental data have been fitted using the FITEQL 4.0 program. Two monodentate inner-sphere surface complexes have been used to fit selenite ions retention, triple bond FeSeO(3)(-) and triple bond FeHSeO(3). In order to fit sorption of silicic acid, the two following surface complexes, namely triple bond FeH(3)SiO(4), and triple bond FeH(2)SiO(4)(-), have been used. Using the surface complexation constants coming from these two binary systems, prediction curves of the effect of silicic acid on the retention of selenium (IV) onto hematite have been obtained. Finally, performed experiments showed a competition between selenium (IV) and silicic acid for the surface sites of hematite. Experimental data matched DDLM predictions, confirming the ability of the surface complexation model to predict quantitatively and qualitatively the ternary system selenium (IV)/H(4)SiO(4)/hematite. PMID:19110295

  5. Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue

    NASA Technical Reports Server (NTRS)

    Chisnell, J. R.

    1984-01-01

    Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetate acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot.

  6. A conformational study of nucleic acid phosphate ester bonds using phosphorus-31 nuclear magnetic resonance.

    PubMed Central

    Haasnoot, C A; Altona, C

    1979-01-01

    A systematic phosphorus-31 nuclear magnetic resonance study of some nucleic acid constituents (6-N-(dimethyl)adenylyl-(3',5')-uridine and some nucleotide methyl esters) is presented. The temperature dependent phosphorus-31 chemical shifts were analyzed by standard thermodynamic procedures. It is shown that gt conformations about the P-O ester bonds have a lower free energy content relative to gg conformers. PMID:440971

  7. Enzymatic resolution of Z- ?, ??-di- tert-butyl-D,L-carboxyglutamic acid methyl ester

    Microsoft Academic Search

    Pere Clapés; Isabel Valverde; Carles Jaime; Josep Lluís Torres

    1996-01-01

    A rapid and simple method for the resolution of Z-?,??-di-tert-butyl-D,L-carboxyglutamic acid methyl ester is described. The new procedure is based on the enzymatic enantioselective saponification of the methyl ester by the endoprotease papain. Using a simple HPLC protocol the enantiomeric excess of Z-di-tert-butyl-L-Gla-OH has been shown to be higher than 99.5%. The procedures described in this communication allow the resolution,

  8. Synthesis, primary photophysical and antibacterial properties of naphthyl ester cinoxacin and nalidixic acid derivatives

    Microsoft Academic Search

    Franklin Vargas; Tamara Zoltan; Carlos Rivas; Alvaro Ramirez; Tulynan Cordero; Yrene Díaz; Carla Izzo; Ylec M. Cárdenas; Verónica López; Lubimar Gómez; Jessenia Ortega; Alberto Fuentes

    2008-01-01

    We have synthesized two naphthyl ester quinolone derivates and determined their ability to generate reactive oxygen species (ROS) such as 1O2, OH, H2O2 upon photolysis with UV-A light. The ability of cinoxacin (1) and nalidixic acid (2), and their naphthyl ester derivatives (3 and 4) to generate a dose-dependent amount of singlet oxygen and ROS (?O2, OH) in cell-free systems

  9. Application of high vacuum fractional distillation to complex mixtures of methyl esters of polyunsaturated fatty acids

    Microsoft Academic Search

    O. S. Privett; J. D. Nadenicek; F. J. Pusch; E. C. Nickell

    1969-01-01

    A technique for the high vacuum fractional distillation, with a spinning band column, of methyl esters of polyunsaturated\\u000a fatty acids employing a carrier of long chain acetates is described. The carrier is used to facilitate the fractionation of\\u000a minor components and minimize artifact formation in mixtures of methyl esters containing up to six double bonds. The technique\\u000a is demonstrated on

  10. 21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

  11. 21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids). 573.637 Section 573.637 Food... Methyl esters of conjugated linoleic acid (cis-9, trans-11 and...

  12. 40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol, fumaric acid and propylene glycol. 721.10457 ...721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc.,...

  13. 40 CFR 721.10457 - 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc., cyclohexanol, 2-ethyl-1-hexanol, fumaric acid and propylene glycol. 721.10457 ...721.10457 1,2-Benzenedicarboxylic acid, mixed esters with benzyl alc.,...

  14. 75 FR 50926 - 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol, polyethylene...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ...EPA-HQ-OPP-2010-0272; FRL-8837-5] 2-propenoic acid, 2-methyl-, C12-16-alkyl esters...tolerance for residues of 2-propenoic acid, 2-methyl-, C12-16- alkyl esters...permissible level for residues of 2-propenoic acid, 2-methyl-, C12-16-alkyl...

  15. Access to aryl mellitic acid esters through a surprising oxidative esterification reaction.

    PubMed

    Geraskina, Margarita R; Juetten, Mark J; Winter, Arthur H

    2014-06-01

    A serendipitously discovered oxidative esterification reaction of cyclohexane hexacarboxylic acid with phosphorus pentachloride and phenols provides one-pot access to previously unknown aryl mellitic acid esters. The reaction features a solvent-free digestion and chromatography-free purifications and demonstrates the possibility of cyclohexane-to-benzene conversions under relatively mild, metal-free conditions. PMID:24815576

  16. A gastroprotective anti-inflammatory agent: the ? -morpholinoethyl ester of niflumic acid (morniflumate)

    Microsoft Academic Search

    P. Schiantarelli; S. Cadel; D. Acerbi

    1984-01-01

    In several animal models orally administered morniflumate, the ?-morpholinoethyl ester of niflumic acid, proved almost equal to the parent compound in anti-inflammatory, analgesic and antipyretic activity with the advantage of complete freedom from the ulcerogenic effects of the acidic parent compound. Further, it was 5 times less active in intestinal perforation experiments and 10 times less toxic in acute toxicity

  17. Amino acids and glycine ethyl ester as new crystallization reagents for lysozyme

    PubMed Central

    Ito, Len; Shiraki, Kentaro; Yamaguchi, Hiroshi

    2010-01-01

    Several amino acids and their derivatives are prominent additives in the field of protein chemistry. This study reports the use of charged amino acids and glycine ethyl ester as precipitants in protein crystallization, using hen egg-white lysozyme (HEWL) as a model. A discussion of the crystallization of HEWL using these reagents as precipitating agents is given. PMID:20516616

  18. A comprehensive evaluation of the density of neat fatty acids and esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Density is one of the most important physical properties of a chemical compound, affecting numerous applications. An application in the case of fatty acid esters (biodiesel) is that density is specified in some biodiesel standards. In the present work, the density of fatty acid methyl, ethyl, propyl...

  19. Electrolytic reduction of abscisic acid methyl ester and its free acid.

    PubMed

    Hirai, Nobuhiro; Iwami, Kumiko; Horiuchi, Mari; Kano, Kenji; Todoroki, Yasushi; Ohigashi, Hajime

    2012-08-01

    Abscisic acid (ABA, 1), a plant hormone, has electrophilicity derived almost entirely from the side-chain, 3-methylpenta-2,4-dienoic acid. The electrochemical property of ABA was investigated by analysis of its cathodic reaction. ABA methyl ester (1-Me) was reduced at a peak potential of -1.6 V to give a unique and unstable bicyclic compound (5-Me) as a major product at pH 3 and 7. This finding showed that an electron was absorbed in the conjugated dienecarboxyl group, and that C-5 with a high electron density attacked C-2' through an intramolecular nucleophilic addition. At pH 10, in addition to 5-Me, a compound 4-Me was formed by isomerization of 5-Me under alkaline conditions. For a cathodic reaction of ABA at pH 3 and 7, compound 5 was a major product as well as in the case of ABA methyl ester. However, at pH 10, a dimer (6) with an epoxy group, 1'-deoxy-ABA (7) and other compounds were formed instead of compounds 4 and 5. Compounds 4 and 5 were biologically inactive, suggesting the importance of the electrophilic side-chain of ABA for biological activity. PMID:22621775

  20. Fumaric Acid Therapy in Psoriasis: A Double-Blind Comparison between Fumaric Acid Compound Therapy and Monotherapy with Dimethylfumaric Acid Ester

    Microsoft Academic Search

    C. Nieboer; D. de Hoop; P. N. J. Langendijk; A. C. van Loenen; J. Gubbels

    1990-01-01

    In a 4-month double-blind study the effects of dimethylfumaric acid esters (DMFAE-EC) and DMFAE plus salts of monoethylfumaric acid esters (fumaric acid combination, FAC-EC) in enteric-coated tablets were compared in 22 respectively 23 patients with psoriasis. In both groups about 50% showed a considerable improvement, i.e. the initial score was more than halved. The therapeutic effects showed no significant differences

  1. Facile synthesis of acid-labile polymers with pendent ortho esters.

    PubMed

    Cheng, Jing; Ji, Ran; Gao, Shi-Juan; Du, Fu-Sheng; Li, Zi-Chen

    2012-01-01

    This work presents a facile approach for preparation of acid-labile and biocompatible polymers with pendent cyclic ortho esters, which is based on the efficient and mild reactions between cyclic ketene acetal (CKA) and hydroxyl groups. Three CKAs, 2-ethylidene-1,3-dioxane (EDO), 2-ethylidene-1,3-dioxolane (EDL), and 2-ethylidene-4- methyl-1,3-dioxolane (EMD) were prepared from the corresponding cyclic vinyl acetals by catalytic isomerization of the double bond. The reaction of CKAs with different alcohols and diols was examined using trace of p-toluenesulfonic acid as a catalyst. For the monohydroxyl alcohols, cyclic ortho esters were formed by simple addition of the hydroxyl group toward CKAs with ethanol showing a much greater reactivity than iso-propanol. When 1,2- or 1,3-diols were used to react with the CKAs, we observed the isomerized cyclic ortho esters besides the simple addition products. Biocompatible polyols, that is, poly(2-hydroxyethyl acrylate) (PHEA) and poly(vinyl alcohol) (PVA) were then modified with CKAs, and the degree of substitution of the pendent ortho esters can be easily tuned by changing feed ratio. Both the small molecule ortho esters and the CKA-modified polymers demonstrate the pH-dependent hydrolysis profiles, which depend also on the chemical structure of the ortho esters as well as the polymer hydrophobicity. PMID:22176024

  2. Comparative Subchronic Studies on 2,4-Dichlorophenoxyacetic Acid, Amine, and Ester in Rats

    Microsoft Academic Search

    Jeffrey M. Charles; Helen C. Cunny; Ronald D. Wilson; James S. Bus

    1996-01-01

    Forms of 2,4-dichlorophenoxyacetic acid (collectively known as 2,4-D) are herbicides used to control a wide variety of broadleaf and woody plants. Subchronic toxicity studies in rats were conducted on three forms of 2,4-D: the parent form, 2,4-D acid; 2,4-D dimethylamine salt (DMA); and 2,4-D 2-ethylhexyl ester (2-EHE). Doses in the subchronic studies (on an acid equivalent basis) were 0, 1,

  3. Synthesis, characterization and biodegradation of functionalized amino acid-based poly(ester amide)s

    Microsoft Academic Search

    Xuan Pang; Chih-Chang Chu

    2010-01-01

    A series of biodegradable functional amino acid-based poly(ester amide)s (PEA-AG) were designed and synthesized by the solution co-polycondensation of amino acid (l-phenylalanine and dl-2-allylglycine) based monomers and dicarboxylic acid based monomers. Pendant carbon–carbon double bonds located in the dl-2-allylglycine were incorporated into these PEA-AGs, and the double bond contents could be adjusted by tuning the feed ratio of l-phenylalanine to

  4. Lipolysis of menhaden oil triacylglycerols and the corresponding fatty acid alkyl esters by pancreatic lipase in vitro: a reexamination

    Microsoft Academic Search

    A. Kuksis; J. J. Myher

    In order to distinguish between possible fatty acid differences during lumenal lipolysis and cellular absorption, we have reinvestigated the in vitro hydrolysis of menhaden oil and its alkyl esters by pancreatic lipase. For this purpose we in- cubated menhaden oil or its fatty acid methyl and ethyl esters with porcine pancreatic lipase in the presence of bile salts and determined

  5. Synthesis and evaluation of odour-active methionyl esters of fatty acids via esterification and transesterification of butter oil.

    PubMed

    Li, Cheng; Sun, Jingcan; Fu, Caili; Yu, Bin; Liu, Shao Quan; Li, Tianhu; Huang, Dejian

    2014-02-15

    Methionol-derived fatty acid esters were synthesised by both chemical and lipase catalysed esterification between fatty acids and methionol. Beneficial effects of both methods were compared qualitatively and quantitatively by GC-MS/GC-FID results. And the high acid and heat stability of our designed methionyl esters meet the requirement of the food industry. Most importantly, the sensory test showed that fatty acid carbon-chain length had an important effect on the flavour attributes of methionyl esters. Moreover, through Lipozyme TL IM-mediated transesterification, valuable methionol-derived esters were synthesised from the readily available natural material butter oil as the fatty acid source. The conversion of methionol and yield of each methionyl ester were also elucidated by GC-MS-FID. PMID:24128547

  6. Tyrosinase inhibitory effects and antioxidative activities of novel cinnamoyl amides with amino acid ester moiety.

    PubMed

    Fan, Qian; Jiang, Hong; Yuan, Er-Dong; Zhang, Jian-Xun; Ning, Zheng-Xiang; Qi, Sui-Jian; Wei, Qing-Yi

    2012-09-15

    Nine cinnamoyl amides with amino acid ester (CAAE) moiety were synthesized by the conjugation of the corresponding cinnamic acids (cinnamic acid, 4-hydroxy cinnamic acid, ferulic acid and caffeic acid) with amino acid esters, and their inhibitory effects on the activities of mushroom tyrosinase were investigated, using l-3,4-dihydroxyl-phenylalanine (l-DOPA) as the substrate. Among these CAAE amides, ethyl N-[3-(4-hydroxy-3-methoxyphenyl)-1-oxo-2-propen-1-yl]-l-phenylalaninate (b(4)) showed the strongest inhibitory activity; the IC(50) was 0.18 ?M. The IC(50) values, inhibition types, inhibition mechanisms and kinetics of all these CAAE amides were evaluated. A structure-activity relationship (SAR) study found that the inhibitory effects were potentiated with the increasing length of hydrocarbon chains at the amino acid esters and also influenced by the substituents at the styrene groups. Furthermore, the hydroxyl radical scavenging and anti-lipid peroxidation activities of four CAAE derivatives were also investigated. Among these compounds, b(3) (ethyl N-[3-(3,4-dihydroxyphenyl)-1-oxo-2-propen-1-yl]-l-phenylalaninate) and b(4) exhibited potential antioxidant activities. PMID:23107731

  7. Process for the generation of .alpha., .beta.-unsaturated carboxylic acids and esters using niobium catalyst

    DOEpatents

    Gogate, Makarand Ratnakav (Durham, NC); Spivey, James Jerome (Cary, NC); Zoeller, Joseph Robert (Kingsport, TN)

    1999-01-01

    A process using a niobium catalyst includes the step of reacting an ester or carboxylic acid with oxygen and an alcohol in the presence a niobium catalyst to respectively produce an .alpha.,.beta.-unsaturated ester or carboxylic acid. Methanol may be used as the alcohol, and the ester or carboxylic acid may be passed over the niobium catalyst in a vapor stream containing oxygen and methanol. Alternatively, the process using a niobium catalyst may involve the step of reacting an ester and oxygen in the presence the niobium catalyst to produce an .alpha.,.beta.-unsaturated carboxylic acid. In this case the ester may be a methyl ester. In either case, niobium oxide may be used as the niobium catalyst with the niobium oxide being present on a support. The support may be an oxide selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide and mixtures thereof. The catalyst may be formed by reacting niobium fluoride with the oxide serving as the support. The niobium catalyst may contain elemental niobium within the range of 1 wt % to 70 wt %, and more preferably within the range of 10 wt % to 30 wt %. The process may be operated at a temperature from 150 to 450.degree. C. and preferably from 250 to 350.degree. C. The process may be operated at a pressure from 0.1 to 15 atm. absolute and preferably from 0.5-5 atm. absolute. The flow rate of reactants may be from 10 to 10,000 L/kg.sub.(cat) /h, and preferably from 100 to 1,000 L/kg.sub.(cat) /h.

  8. Rice Hull Ash and Silicic Acid as Adsorbents for Concentration of Bacteriocins

    Microsoft Academic Search

    M. E. JANES; R. NANNAPANENI; A. PROCTOR; M. G. JOHNSON

    1998-01-01

    A model procedure has been developed for the rapid extraction of five bacteriocins (nisin, pediocin RS2, leucocin BC2, lactocin GI3, and enterocin CS1) from concentrated freeze-dried crude culture supernatants by adsorption onto acid or alkaline rice hull ash (RHA) or silicic acid (SA). Bacteriocins were adsorbed onto RHA or SA by a pH-dependent method and desorbed by decreasing the pH

  9. A quantitation problem in the open tubular gas chromatography of fatty acid esters from cod liver lipids

    Microsoft Academic Search

    R. G. Ackman; J. C. Sipos; P. M. Jangaard

    1967-01-01

    Methyl esters of fatty acids of marine origin contain large amounts of highly unsaturated long-chain fatty acids. It is shown\\u000a that, although esters of saturated and monounsaturated fatty acids can be quantitatively analyzed on open tubular columns\\u000a with a flame ionization detector there are serious losses of the long-chain highly unsaturated fatty acids of marine oils\\u000a on the column. Through

  10. Immunomodulatory effect of caffeic acid phenethyl ester in Balb\\/c mice

    Microsoft Academic Search

    Jae Hyun Park; Jong Kwon Lee; Hyung Soo Kim; Seung Tae Chung; Juno H. Eom; Kyung A. Kim; Se Jin Chung; Soon Young Paik; Hye Young Oh

    2004-01-01

    Caffeic acid phenethyl ester (CAPE), an the active component of propolis, is known to have anticarcinogenic, antiviral and various biological activities; however, the effect of CAPE on the immunomodulatory activity in vivo remains unknown. We have investigated the effect of CAPE on the immune system in female Balb\\/c mice. CAPE (0, 5, 10, 20 mg\\/kg) was given to mice orally

  11. SEPARATION OF T-MAZ ETHOXYLATED SORBITAN FATTY ACID ESTERS BY REVERSE PHASE CHROMATOGRAPHY

    EPA Science Inventory

    The method for determination of T-MAZ ethoxylated sorbitan fatty acid esters is described. This work demonstrates that with a less retentive C8 alkyl bonded phase packing, reverse phase chromatography can be used to analyze nonionic polymer mixtures with a molecular weight range ...

  12. Cold flow properties of fatty acid methyl esters: Additives versus diluents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is typically composed of fatty acid methyl esters (FAME) converted from agricultural lipids. Common feedstocks include soybean oil, canola oil, rapeseed oil, sunflower oil, and palm oil. Recent debate on the conversion of edible oils into non-food products has created opportunities to deve...

  13. Infrared Study of the Molecular Orientation in Ultrathin Films of Behenic Acid Methyl Ester: Comparison between

    E-print Network

    Pezolet, Michel

    Infrared Study of the Molecular Orientation in Ultrathin Films of Behenic Acid Methyl Ester-Blodgett transfer. The presence in the infrared spectra of several bands due to the methylene wagging and twisting and infrared spectroscopy have been developed to study these films. Infrared spectroscopy is particularly

  14. Phthalate acid esters in Potamogeton crispus L. from Haihe River, China

    Microsoft Academic Search

    Jie Chi

    2009-01-01

    This study was conducted in Haihe River, China, in order to assess the ability of Potamogeton crispus L. (P. crispus), a submerged plant, to accumulate phthalic acid esters (PAEs). Dibutyl phthalate (DBP) and di-2-ethylexyl phthalate (DEHP) were measured in samples of water, sediment and P. crispus plant from March to May 2008. The results showed that the highest levels of

  15. New materials for solar thermal storage—solid\\/liquid transitions in fatty acid esters

    Microsoft Academic Search

    R Nikoli?; M Marinovi?-Cincovi?; S Gadžuri?; I. J Zsigrai

    2003-01-01

    Solid\\/liquid transitions were studied by DSC measurements in the following fatty acid esters: methyl stearate, methyl palmitate, cetyl stearate, cetyl palmitate and their binary mixtures. Four systems, with phase transition temperature close to room temperature and with high enthalpy of transition and low hysteresis, were selected for further studies relevant to passive solar thermal storage. The selected systems were: methyl

  16. Pretreatment of yellow grease for efficient production of fatty acid methyl esters

    Microsoft Academic Search

    Walterio Diaz-Felix; Mark R. Riley; Werner Zimmt; Michael Kazz

    2009-01-01

    Biodiesel is a renewable fuel comprised of fatty acid methyl esters (FAME) derived from vegetable oils or animal fats. Comparisons between biodiesel and petroleum-based diesel have shown biodiesel to be effective in reducing exhaust emissions of carbon monoxide, hydrocarbons, particulate matter, and sulfur dioxide. While there are advantages of biodiesel over the traditional petroleum based diesel, biodiesel commercialization is limited

  17. Esterification and transesterification of greases to fatty acid methyl esters with highly active diphanylammonium salts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have conducted an investigation designed to identify alternate catalysts for the production of fatty acid methyl esters (FAME) to be used as biodiesel. Diphenylammonium sulfate (DPAS) and diphenylammonium chloride (DPA-HCl) salts were found to be highly active homogeneous catalysts for the simu...

  18. 40 CFR 721.10542 - Dodecanedioic acid, 1,12-dimethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (1) The chemical substance identified as dodecanedioic acid, 1,12-dimethyl ester (PMN P-03-624; CAS No. 1731-79-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  19. Fumaric acid esters in necrobiosis lipoidica: results of a prospective noncontrolled study

    Microsoft Academic Search

    A. Kreuter; C. Knierim; M. Stucker; F. Pawlak; S. Rotterdam; P. Altmeyer; T. Gambichler

    2005-01-01

    Summary Background Necrobiosis lipoidica (NL) is an uncommon granulomatous skin dis- ease with association to diabetes mellitus. To date, no proven effective therapy for NL has been implemented. The standard treatment is topical application of corticosteroids, but numerous agents have been reported for NL, with varying degrees of success. In recent case reports, fumaric acid esters (FAE) have been reported

  20. Fumaric Acid Esters Suppress Peripheral CD4- and CD8Positive Lymphocytes in Psoriasis

    Microsoft Academic Search

    S. Höxtermann; C. Nüchel; P. Altmeyer

    1998-01-01

    Background: For severe forms of psoriasis vulgaris, the antipsoriatic fumaric acid esters (FAE) therapy has recently gained increasing acceptance and importance. Until today, there is little knowledge about the mode of action of FAE. However, some evidence exists indicating immunosuppressive effects. Objective: The aim of this study was to examine the systemic, particularly the immunological changes in patients suffering from

  1. Catalytic synthesis of fatty acid methyl esters from extremely low quality greases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel (BD) is a renewable fuel for compression ignition engines that is composed of the simple alkyl esters, usually methyl-, of fatty acids (FAME). It is typically produced via base-catalyzed transesterification between refined vegetable oil or animal fat (e.g., soybean oil, tallow) and an alc...

  2. Interest of ferulic acid ethyl ester in photoprotective creams: Measure of efficacy by in vitro method

    Microsoft Academic Search

    Benjamin Choquenet; Celine Couteau; Eva Paparis; Laurence J. M. Coiffard

    2008-01-01

    Topical sunscreens have been used for many years on exposed areas to protect the skin from the damaging effects of ultraviolets. If the sunscreens were essential, it is suggested that they have adverse effects. We chose to study ferulic acid ethyl ester (FAEE) as agent which could potentially be used in sunscreen products. FAEE was incorporated at various concentrations into

  3. Porphyrin synthesis from aminolevulinic acid esters in endothelial cells and its role in photodynamic therapy

    Microsoft Academic Search

    Lorena Rodriguez; Henriëtte S. de Bruijn; Gabriela Di Venosa; Leandro Mamone; Dominic J. Robinson; Angeles Juarranz; Alcira Batlle; Adriana Casas

    2009-01-01

    Photodynamic therapy (PDT) may cause tumour cell destruction by direct toxicity or by inducing microcirculatory shutdown. Protoporphyrin IX generated from 5-aminolevulinic acid (ALA) has been widely used as an endogenous photosensitiser in PDT. However, the hydrophilic nature of the ALA molecule limits its penetration through the stratum corneum of the skin and cell membranes and thus, ALA alkyl-esters have been

  4. Beyond fatty acid methyl esters: Expanding the renewable carbon profile with alkenones from Isochrysis sp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to characteristic fatty acid methyl esters (FAMEs), biodiesel produced from Isochrysis sp. contains a significant amount (14% dry weight) of predominantly C37 and C38 longchain alkenones. These compounds are members of a class of lipids known collectively as polyunsaturated long-chain al...

  5. Use of vegetable oils and fatty acid methyl esters in the production of spherical activated carbons

    Microsoft Academic Search

    S Gryglewicz; K Grabas; G Gryglewicz

    2000-01-01

    The possibility of using vegetable oils, i.e., rapeseed oil, soybean oil, linseed oil, tung oil, castor oil and dehydroxylated castor oil, and the fatty acid methyl esters (FAMEs) obtained from them, for the agglomeration of bituminous coals was investigated. Both vegetable oils and FAMEs were found to be suitable bridging liquids for the production of spherical agglomerates-precursor of spherical activated

  6. Encapsulation of ployunsaturated fatty acid esters with solid lipid particles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyunsaturated fatty acids (PUFA) such as a-linolenic acid (ALA) and docosahexaenoic acid (DHA) are known to improve cardiovascular and nervous system health. These compounds are increasingly used in food and animal feed formulations. However, the high degree of unsaturation in these structures can...

  7. 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

    ...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant...azo-al-kyl-a-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to...

  8. 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

    ...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection...azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant...azo-al-kyl-a-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to...

  9. 40 CFR 721.10271 - 3?H-Cyclopropa[1,9][5,6]fullerene-C60-Ih-3?-butanoic acid, 3?-phenyl-, methyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...fullerene-C60-Ih-3â²-butanoic acid, 3â²-phenyl-, methyl ester. 721.10271 Section...fullerene-C60-Ih-3?-butanoic acid, 3?-phenyl-, methyl ester. (a) Chemical...fullerene-C60-Ih-3?-butanoic acid, 3?-phenyl-, methyl ester,...

  10. 40 CFR 721.10271 - 3?H-Cyclopropa[1,9][5,6]fullerene-C60-Ih-3?-butanoic acid, 3?-phenyl-, methyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...fullerene-C60-Ih-3â²-butanoic acid, 3â²-phenyl-, methyl ester. 721.10271 Section...fullerene-C60-Ih-3?-butanoic acid, 3?-phenyl-, methyl ester. (a) Chemical...fullerene-C60-Ih-3?-butanoic acid, 3?-phenyl-, methyl ester,...

  11. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), ?-methyl-?-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...methyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1731 Section...?-methyl-?-hydroxy, ester with boric acid (H3BO3). (a) Chemical substance...?-methyl-?-hydroxy, ester with boric acid (H3 BO3 ) (PMN...

  12. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), ?-butyl-?-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...butyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1730 Section...?-butyl-?-hydroxy, ester with boric acid (H3BO3). (a) Chemical substance...?-butyl-?-hydroxy, ester with boric acid (H3 BO3 ) (PMN...

  13. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), ?-methyl-?-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...methyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1731 Section...?-methyl-?-hydroxy, ester with boric acid (H3BO3). (a) Chemical substance...?-methyl-?-hydroxy, ester with boric acid (H3 BO3 ) (PMN...

  14. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), ?-butyl-?-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...butyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1730 Section...?-butyl-?-hydroxy, ester with boric acid (H3BO3). (a) Chemical substance...?-butyl-?-hydroxy, ester with boric acid (H3 BO3 ) (PMN...

  15. SYNTHESIS AND STRUCTURE OF THE COMPLEXES OF ESTERS OF SOME PHOSPHONIC ACIDS AND AMIDES WITH MOLYBDENUM DIOXODICHLORIDE

    Microsoft Academic Search

    E. T. K. Haupt; J. Kopf; J. Petrova; S. Momchilova

    2002-01-01

    The complexes L?MoO2Cl2 (2), L?·MoO2Cl2 (4), L??·MoO2Cl2 (6) and L????MoO2Cl2 (8) were obtained by the reaction of MoO2Cl2 and the ligands: L=diethyl ester of 2-dimethylamino-2-oxoethylphosphonic acid (1), L?=diethyl ester of 2-amino-2-oxoethylphosphonic acid (3), L??=tetraethyl ester of methylenediphosphonic acid (5) and L???=tetraethylester of ethylenediphosphonic acid (7). They were characterized by elemental analyses, IR and NMR spectroscopy. The crystal structure of the

  16. Synthesis of N -hydroxycinnamoyl amino acid ester analogues and their free radical scavenging and antioxidative activities

    Microsoft Academic Search

    Qing-Yi WeiHong; Hong Jiang; Jian-Xun Zhang; Peng-Fei Guo; Huan Wang

    Hydroxycinnamic acids have a variety of biological activities, including antioxidant activity. To find more active antioxidants\\u000a with hydroxycinnamoyl moiety, we synthesized a series of N-hydroxycinnamoyl amino acid esters and evaluated their antioxidative activities by 2,2-diphenyl-1-picryl hydrazyl (DPPH)\\u000a radical scavenging and human red blood cells (RBCs) haemolysis methods. It was found that N-caffeoyl amides exhibited the highest DPPH-scavenging activities, whereas N-feruloyl

  17. The Effects of Caffeic Acid Phenethyl Ester (CAPE) on TNBS-induced Colitis in Ovariectomized Rats

    Microsoft Academic Search

    Rauf Onur Ek; Mukadder Serter; Kemal Ergin; Yuksel Yildiz; Serpil Cecen; Tulay Kavak; Cigdem Yenisey

    2008-01-01

    Aim The aim of this investigation was to examine the effects of caffeic acid phenethyl ester (CAPE) on the development of colitis\\u000a and antioxidant parameters in bilateral ovariectomized rats subjected to trinitrobenzene sulfonic acid (TNBS)-induced colitis.\\u000a Materials and methods Twenty-one Wistar Albino ovariectomized female rats were divided into four subgroups (n = 5 or 6) (colitis control, vehicle control, CAPE 10 and

  18. Anaerobic degradation of phthalic acid esters during digestion of municipal solid waste under landfilling conditions

    Microsoft Academic Search

    J. Ejlertsson; U. Meyerson; B. H. Svensson

    1996-01-01

    Anaerobic microorganisms in municipal solid waste samples from laboratory-scale landfill reactors and a pilot-plant biogas digestor were investigated with the aim of assessing their ability to transform four commercially used phthalic acid esters (PAEs) and phthalic acid (PA). The PAEs studied were diethyl phthalate (DEP), butylbenzyl phthalate (BBP), dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP). No biological transformation of DEHP

  19. Decomposition mechanism of the tert-butyl esters of carboxylic acids

    Microsoft Academic Search

    V. G. Avakyan; A. D. Litmanovich; V. O. Cherkezyan

    1984-01-01

    1.It has been shown by quantum-chemical calculations that the monomolecular decomposition of tert-butyl esters ot carboxylic acids, which involves the detachment of isobutylene, takes place as the result of the transfer of a proton from the closest CH3 group of the tert-butyl substituent to the carbonyl O atom.2.The catalytic action of carboxylic acids on this reaction is exhibited by the

  20. Preparation of fatty acid methyl esters for gas-chromatographic analysis of lipids in biological materials

    Microsoft Academic Search

    Ke-Shun Liu

    1994-01-01

    Theoretically, preparation of fatty acid methyl esters (FAMEs) deals with reversible chemical reactions in a complex system.\\u000a Methodologically, there are numerous ways, generally characterized by the type of catalysts used and steps involved. Although\\u000a there are more than a half dozen common catalysts, the majority fall into either acidic (HCl, H2SO4 and BF3) or alkaline types (NaOCH3, KOH and NaOH),

  1. The Southern Ocean silicon trap: Data-constrained estimates of regenerated silicic acid, trapping efficiencies, and global transport paths

    NASA Astrophysics Data System (ADS)

    Holzer, Mark; Primeau, François W.; DeVries, Timothy; Matear, Richard

    2014-01-01

    We analyze an optimized model of the global silicon cycle embedded in a data-assimilated steady ocean circulation. Biological uptake is modeled by conditionally restoring silicic acid in the euphotic zone to observed concentrations where the modeled concentrations exceed the observational climatology. An equivalent linear model is formulated to which Green-function-based transport diagnostics are applied. We find that the models' opal export through 133 m depth is 166 ± 24 Tmol Si/yr, with the Southern Ocean (SO) providing ˜70% of this export, ˜50% of which dissolves above 2000 m depth. The global-scale gradients of the opal dissolution rate are primarily meridional, while the global-scale gradients of phosphate remineralization are primarily vertical. The mean depth of the temperature-dependent silicic-acid regeneration reaches 2300 m in the SO, compared to 600 m for phosphate remineralization. Silicic acid is stripped out of the euphotic zone far more efficiently than phosphate, with only (34 ± 5)% of the global silicic-acid inventory being preformed, compared to (61 ± 7)% for phosphate. Subantarctic and tropical waters contribute most of the ocean's regenerated silicic acid, while Antarctic waters provide most of the preformed silicic acid. About half of the global silicic-acid inventory is trapped in transport paths connecting successive SO utilizations, with silicic acid last utilized in the SO having only a (5 ± 2)% chance of being next utilized outside the SO. This trapping depletes subantarctic mode waters of silicic acid relative to phosphate, which has a (44 ± 2)% probability of escaping successive SO utilization.

  2. Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    DOEpatents

    Moens, Luc (Lakewood, CO)

    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.

  3. Enhancement of the mutagenicity of amino acid pyrolysates by phthalate esters.

    PubMed

    Sato, T; Nagase, H; Sato, K; Niikawa, M; Kito, H

    1994-01-01

    The ability of phthalic acid, phthalic acid anhydride, and various phthalate esters to enhance the mutagenicity of many amino acid pyrolysates was observed with the Ames test (Salmonella typhimurium TA98), but not the SOS Chromotest. Phthalate enhancement of the mutagenicity of 4-nitroquinoline-1-oxide, 2-nitrofluorene, and benzo[a]pyrene was not observed with either test. The mutagenicity-enhancing ability may be related to the induction of enzymes such as P450IIB, that metabolize amino acid pyrolysates. By quantitative structure activity relationship (QSAR) analysis, a good correlation was observed between the mutagenicity-enhancing activity of phthalates and their octanol-water partition coefficients. PMID:7851345

  4. Isolation of natural arachidonic acid as its methyl ester

    Microsoft Academic Search

    S. F. Herb; R. W. Riemenschneider; Jeanette Donaldson

    1951-01-01

    Summary  Fresh beef suprarenal glands were ground and extracted thoroughly with alcohol and then with ethyl ether. After removal of\\u000a solvent the total lipid residue was saponified, and the fatty acids were recovered by extraction. The less unsaturated acids\\u000a were removed by crystallization from acetone at ?40C. At this stage the filtrate contained essentially all the arachidonic\\u000a acid originally present in

  5. Sinapic acid ester metabolism in wild type and a sinapoylglucose-accumulating mutant of arabidopsis.

    PubMed Central

    Lorenzen, M; Racicot, V; Strack, D; Chapple, C

    1996-01-01

    Sinapoylmalate is one of the major phenylpropanoid metabolites that is accumulated in the vegetative tissue of Arabidopsis thaliana. A thin-layer chromatography-based mutant screen identified two allelic mutant lines that accumulated sinapoylglucose in their leaves in place of sinapoylmalate. Both mutations were found to be recessive and segregated as single Mendelian genes. These mutants define a new locus called SNG1 for sinapoylglucose accumulator. Plants that are homozygous for the sng1 mutation accumulate normal levels of malate in their leaves but lack detectable levels of the final enzyme in sinapate ester biosynthesis, sinapoylglucose:malate sinapoyltransferase. A study of wild-type and sng1 seedlings found that sinapic acid ester biosynthesis in Arabidopsis is developmentally regulated and that the accumulation of sinapate esters is delayed in sng1 mutant seedlings. PMID:8972602

  6. Resolution of diastereomeric flavonoid (1S)-(-)-camphanic acid esters via reversed-phase HPLC.

    PubMed

    Philbin, Casey S; Schwartz, Steven J

    2007-04-01

    Prenylflavonoids are an unique class of phytochemicals found in the inflorescences of the hop plant (Humulus lupulus). These flavonoids have demonstrated a wide range of biological activities, which may be influenced by their stereochemical configuration. Additionally, recent studies suggest that hop prenylflavonoids are subject to biotransformations which could alter or enrich their stereochemistry. In order to facilitate studies of the stereoisomers of flavanones, a facile method was developed for resolving the diastereomeric esters of flavanones via reversed-phase HPLC. Herein, a method for forming the tri-(1S)-(-)-camphanic acid esters of the 4',5,7-trihydroxy flavanones naringenin, 8-prenylnaringenin and 6-prenylnaringenin, is described. The respective diastereomers were separated using analytical reversed-phase HPLC. Diastereomeric esters were isolated by preparative HPLC to >98% d.e. based on HPLC, with their absolute configurations established by application of CD spectrometry. PMID:17363016

  7. Citric acid esters from fruit of Lonicera caerulea

    Microsoft Academic Search

    E. V. Anikina; A. L. Vereshchagin; A. I. Syrchina; F. Larin; A. A. Semenov

    1988-01-01

    Compound (I) could be formed from the corresponding acid by methylation with diazomethane. The native nature of (I)was confirmed by its isolation from the initial unmethylated fraction after the elimination of citric acid from it with the use of AV-17 ion-exchange resin. The isolation of 7-oxologanin from plants of the genus Lonicera has not been reported previously.

  8. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...mixture of stearic, oleic, and coconut fatty acids are used as a cloud inhibitor in vegetable and salad oils when use is not precluded...a level not in excess of the amount required to perform its cloud-inhibiting effect. Oleic acid derived from tall oil...

  9. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...mixture of stearic, oleic, and coconut fatty acids are used as a cloud inhibitor in vegetable and salad oils when use is not precluded...a level not in excess of the amount required to perform its cloud-inhibiting effect. Oleic acid derived from tall oil...

  10. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...mixture of stearic, oleic, and coconut fatty acids are used as a cloud inhibitor in vegetable and salad oils when use is not precluded...a level not in excess of the amount required to perform its cloud-inhibiting effect. Oleic acid derived from tall oil...

  11. The kinetics and mechanisms of the reactions of aluminium(III) with gallic acid, gallic acid methyl ester and adrenaline

    Microsoft Academic Search

    Máirt??n ӒCoinceanainn; Michael J. Hynes

    2001-01-01

    The kinetics and mechanisms of the reactions of gallic acid, gallic acid methyl ester and adrenaline with aluminium(III) have been investigated in aqueous solution at 25°C and an ionic strength of 0.5 M. A mechanism has been proposed which accounts satisfactorily for the kinetic data. This is consistent with a mechanism in which complex formation takes place almost exclusively by

  12. The effects of solvent mixtures on the gel permeation chromatography of alkanes, fatty acids, and fatty acid esters 

    E-print Network

    Bolton, Patrick Lee

    1985-01-01

    -alkanes, fatty acids, and methyl and butyl fatty acid esters were separated on a crosslinked polystyrene- divinylbenzene column in mixtures of THF with 1, 4-dioxane, toluene, benzene, acetone, methyl ethyl ketone, and o-dichlorobenzene. A sample of phenolic... in the preparation of this thesis. vi TABLE OF CONTENTS CHAPTER Page I INTRODUCTION Gel Permeation Chromatography of Small Molecules Objectives 1 4 II REVIEW OF LITERATURE GPC of Small Molecules, Current Research GPC, Solvent Mixtures 6 8 III MATERIALS...

  13. Comparison of infrared spectrophotometric and lead salt-alcohol methods for determination of trans octadecenoic acids and esters

    Microsoft Academic Search

    Daniel Swern; H. B. Knight; O. D. Shreve; M. R. Heether

    1950-01-01

    Summary  The scope and limitations of the lead salt-alcohol method (11, 19) have been defined as a result of observations in the authors'\\u000a laboratories and in others. Trans octadecenoic acids and esters are not determined specifically by this method, and when large\\u000a amounts of cis acids or esters are present, they are also isolated with the solid acid fraction.\\u000a \\u000a The infrared

  14. Water chemical ionization mass spectrometry of aldehydes, ketones esters, and carboxylic acids

    SciTech Connect

    Hawthorne, S.B.; Miller, D.J.

    1986-11-01

    Chemical ionization mass spectrometry (CI) of aliphatic and aromatic carbonyl compounds using water as the reagent gas provides intense pseudomolecular ions and class-specific fragmentation patterns that can be used to identify aliphatic aldehydes, ketones, carboxylic acids, and esters. The length of ester acyl and alkyl groups can easily be determined on the basis of loss of alcohols from the protonated parent. Water CI provides for an approximately 200:1 selectivity of carbonyl species over alkanes. No reagent ions are detected above 55 amu, allowing species as small as acetone, propanal, acetic acid, and methyl formate to be identified. When deuterate water was used as the reagent, only the carboxylic acids and ..beta..-diketones showed significant H/D exchange. The use of water CI to identify carbonyl compounds in a wastewater from the supercritical water extraction of lignite coal, in lemon oil, and in whiskey volatiles is discussed.

  15. Effects of metadoxine on cellular formation of fatty acid ethyl esters in ethanol treated rats.

    PubMed

    Calabrese, V; Calderone, A; Ragusa, N; Rizza, V

    1995-01-01

    Free fatty acids (FFA) and fatty acid ethyl esters (FAEE) were extracted from different organs of rats administered ethanol, which was found to have induced FAEE formation, which reached its highest levels in the heart, followed by kidney, brain and liver; the ethanol administration resulted also in a marked increase of total FFA content, particularly in brain, kidney, heart and liver. Pretreatment of animals with Metadoxine one hour before ethanol administration inhibited significantly both FAEE and FFA accumulation in all organs examined. These effects were concomitant with the decreased levels of ethanol in blood found in alcohol-intoxicated rats pretreated with Metadoxine. Our results point to the role of fatty acid ethyl esters as possible mediators in the production of alcohol-dependent syndromes, especially in organs lacking oxidative pathways. Administration of Metadoxine, through an increment in alcohol metabolism and turnover, greatly reduces this metabolic abnormality, warranting its potential usefulness as a pharmacological tool in alcoholism management. PMID:8867649

  16. Study of UltraHigh Performance Supercritical Fluid Chromatography to measure free fatty acids with out fatty acid ester preparation.

    PubMed

    Ashraf-Khorassani, M; Isaac, G; Rainville, P; Fountain, K; Taylor, L T

    2015-08-01

    Most lipids are best characterized by their fatty acids which may differ in (a) chain length, (b) degree of unsaturation, (c) configuration and position of the double bonds, and (d) the presence of other functionalities. Thus, a fast, simple, and quantitative analytical technique to determine naturally occurring free fatty acids (FFA) in different samples is very important. Just as for saponified acylglycerols, the determination of FFA's has generally been carried out by high resolution gas chromatography (HRGC). The use of an open tubular capillary column coupled with a flame ionization or mass spectrometric detector provides for both high resolution and quantification of FFA's but only after conversion of all free fatty acids to fatty acid methyl esters (FAME) or pentafluorobenzyl esters. Unfortunately, volatilization of labile ester derivatives of mono- and poly-unsaturated FFA's can cause both thermal degradation and isomerization of the fatty acid during HRGC. The employment of a second generation instrument (here referred to as UltraHigh Performance Supercritical Fluid Chromatograph, UHPSFC) with high precision for modified flow and repeated back pressure adjustment in conjunction with sub-2?m various bonded silica particles (coupled with evaporative light scattering, ELSD, and mass spectrometric, MS, detection) for separation and detection of the following mixtures is described: (a) 31 free fatty acids, (b) isomeric FFA's, and (c) lipophilic materials in two real world fish oil samples. Limits of detection for FFA's via UHPSFC/MS and UHPSFC/ELSD versus detection of FAME's via HRGC/MS are quantitatively compared. PMID:26093119

  17. Synthesis and transdermal properties of acetylsalicylic acid and selected esters.

    PubMed

    Gerber, Minja; Breytenbach, Jaco C; Hadgraft, Jonathan; du Plessis, Jeanetta

    2006-03-01

    The primary aim of this study was to determine the transdermal penetration of acetylsalicylic acid and some of its derivatives, to establish a correlation, if any, with selected physicochemical properties and to determine if transdermal application of acetylsalicylic acid and its derivatives will give therapeutic drug concentrations with respect to transdermal flux. Ten derivatives of acetylsalicylic acid were prepared by esterification of acetylsalicyloyl chloride with ten different alcohols. The experimental aqueous solubility, logD and transdermal flux values were determined for acetylsalicylic acid and its derivatives at pH 4.5. In vitro penetration was measured through excised female human abdominal skin in diffusion cells. The experimental aqueous solubility of acetylsalicylic acid (6.56 mg/ml) was higher than that of the synthesised acetylsalicylate derivatives (ranging from 1.76 x 10(-3) to 3.32 mg/ml), and the logD of acetylsalicylic acid (-0.85) was lower than that of its derivatives (ranging from -0.25 to 1.95). There was thus an inverse correlation between the aqueous solubility data and the logD values. The experimental transdermal flux of acetylsalicylic acid (263.83 nmol/cm(2)h) was much higher than that of its derivatives (ranging from 0.12 to 136.02 nmol/cm(2)h). PMID:16442756

  18. Photorelease of carboxylic acids, amino acids, and phosphates from N-alkylpicolinium esters using photosensitization by high wavelength laser dyes.

    PubMed

    Sundararajan, Chitra; Falvey, Daniel E

    2005-06-01

    Visible light (>450 nm) is used to efficiently cleave carboxylic acids, amino acids, and phosphates from their N-methyl picolinium esters. Photolysis using pyrromethene dyes PM 546 and PM 597 and also coumarin 6 as photosensitizers effects release of carboxylic acids, N-protected amino acids, and phosphates in quantitative yields. The effective rate of photorelease by the dyes, Phiepsilon, was found to be as high as 4500 M-1 cm-1. The photorelease proceeds through photoinduced electron transfer from the dye sensitizers to the N-methyl picolinium group. Fluorescence quenching and laser flash photolysis experiments support the photoinduced electron-transfer mechanism. PMID:15926809

  19. ORIGINAL ARTICLE -Aminolevulinic acid and its methyl ester induce

    E-print Network

    Lübbert, Hermann

    -dependent with considerably different kinetics for both compounds. While partial inhibition occurred using L-arginine, Pp root ganglion F12 Nutrient mixture F12 GABA -Aminobutyric acid GAT GABA transporter L-Arg L-Arginine

  20. Adsorption and activity of a domoic acid binding antibody fragment on mesoporous silicates.

    PubMed

    Hu, Xuejun; Spada, Stefania; White, Simon; Hudson, Sarah; Magner, Edmond; Wall, J Gerard

    2006-09-21

    The adsorption of an anti-domoic acid single-chain Fv (scFv) antibody fragment onto a range of mesoporous silicate supports was investigated. The scFv fragment adsorbed to all materials investigated, and pI had an apparently large effect on coating, with the greatest-and fastest-adsorption found on the most negatively charged silicates. Maximal coating levels attainable did not reflect the pore diameters of the materials. The immobilized antibody was functional on all materials and bound its antigen, a naturally occurring neurotoxin produced by shellfish, in a rapidly saturating manner that suggested the antibody adsorbed in a multilayer on the mesoporous particles. The antigen:antibody ratio decreased from 1:1.3 to <1:10 with increasing concentration of immobilized antibody, and the immobilized scFv exhibited no detectable reduction in domoic acid binding over a 42-day incubation period. PMID:16970501

  1. Thermochemistry of C-O, (CO)-O, and (CO)-C bond breaking in fatty acid methyl esters

    SciTech Connect

    Osmont, Antoine; Yahyaoui, Mohammed; Catoire, Laurent; Goekalp, Iskender [ICARE-CNRS and University of Orleans, 1C, avenue de la Recherche Scientifique, 45071 Orleans cedex 2 (France); Swihart, Mark T. [Department of Chemical and Biological Engineering, University at Buffalo (SUNY), Buffalo, NY 14260-4200 (United States)

    2008-10-15

    Density functional theory quantum chemical calculations corrected with empirical atomic increments have been used to examine C-O, (CO)-O, and (CO)-C bond scission enthalpies in gas-phase fatty acid methyl esters (FAMEs) present in biodiesel derived from rapeseed oil methyl ester and soybean oil methyl ester. Mechanistic information, currently not available elsewhere for these large species, is obtained based on thermochemical considerations and compared to thermochemical considerations reported for methyl butanoate, a small methyl ester sometimes used as a model for FAMEs. These results are compared to previously reported C-C and C-H bond scissions in these FAMEs, derived using this same protocol. (author)

  2. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 1: Condensation of phthalic anhydride with acetoacetic and malonic ester

    NASA Technical Reports Server (NTRS)

    Oshkaya, V. P.; Vanag, G. Y.

    1985-01-01

    Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ester and a derivative of indan-1,3-dione which after boiling with hydrochloric acid yielded indan-1,3-dione. Phthalylmalonic ester was obtained from phthalic anhydride and malonic ester in the presence of triethylamine.

  3. Metabolic pathway engineering for fatty acid ethyl ester production in Saccharomyces cerevisiae using stable chromosomal integration.

    PubMed

    de Jong, Bouke Wim; Shi, Shuobo; Valle-Rodríguez, Juan Octavio; Siewers, Verena; Nielsen, Jens

    2015-03-01

    Fatty acid ethyl esters are fatty acid derived molecules similar to first generation biodiesel (fatty acid methyl esters; FAMEs) which can be produced in a microbial cell factory. Saccharomyces cerevisiae is a suitable candidate for microbial large scale and long term cultivations, which is the typical industrial production setting for biofuels. It is crucial to conserve the metabolic design of the cell factory during industrial cultivation conditions that require extensive propagation. Genetic modifications therefore have to be introduced in a stable manner. Here, several metabolic engineering strategies for improved production of fatty acid ethyl esters in S. cerevisiae were combined and the genes were stably expressed from the organisms' chromosomes. A wax ester synthase (ws2) was expressed in different yeast strains with an engineered acetyl-CoA and fatty acid metabolism. Thus, we compared expression of ws2 with and without overexpression of alcohol dehydrogenase (ADH2), acetaldehyde dehydrogenase (ALD6) and acetyl-CoA synthetase (acs SE (L641P) ) and further evaluated additional overexpression of a mutant version of acetyl-CoA decarboxylase (ACC1 (S1157A,S659A) ) and the acyl-CoA binding protein (ACB1). The combined engineering efforts of the implementation of ws2, ADH2, ALD6 and acs SE (L641P) , ACC1 (S1157A,S659A) and ACB1 in a S. cerevisiae strain lacking storage lipid formation (are1?, are2?, dga1? and lro1?) and ?-oxidation (pox1?) resulted in a 4.1-fold improvement compared with sole expression of ws2 in S. cerevisiae. PMID:25422103

  4. Highly selective asymmetric synthesis of 2-hydroxy fatty acid methyl esters through chiral oxazolidinone carboximides

    Microsoft Academic Search

    Hong-Sik Hwang; Sevim Z. Erhan

    2001-01-01

    Highly selective asymmetric synthesis of 2-hydroxy fatty acid methyl esters has been accomplioshed through chiral imide enolates.\\u000a Five chiral oleic acid imides were prepared by reaction of oleioc acid with pivaloyl chloride followed by reaction with five\\u000a different lithiated chiral oxazolidinones including (R)-(+)-4-benzyl-2-, (S)-(-)-4-benzyl-2-, (4R,5S)-(+)-4-methyl-5-phenyl-2-, (4S,5R)-(-)-4-methyl-5-phenyl-2-, and (R)-(+)-4-isopropyl-2-oxazolidinones in 88–92% yileds. The chiral imides were reacted with NaN(Me3Si)2 at ?78C

  5. Fumaric Acid and its Esters: An Emerging Treatment for Multiple Sclerosis

    PubMed Central

    Moharregh-Khiabani, D; Linker, R.A; Gold, R; Stangel, M

    2009-01-01

    Fumaric acid is an intermediate product of the citric acid cycle that is a source of intracellular energy in the form of adenosine triphosphate (ATP). It is generated by oxidation of adenylsuccinate by the enzyme succinate dehydrogenase and is then converted to maleate by the enzyme fumarase. At present, fumaric acid esters (FAE) are licensed for the treatment of psoriasis. Several lines of evidence have demonstrated immunomodulatory effects for FAE. Clinical studies in psoriasis showed a reduction of peripheral CD4+- and CD8+-T-lymphocytes due to the ability of FAE to induce apoptosis. In vitro studies with the ester dimethyl fumarate (DMF) described an inhibitory effect on nuclear factor kappa B (NF-?B)-dependent transcription of tumor necrosis factor-alpha (TNF-?) induced genes in human endothelial cells. Animal studies using a model of central nervous system demyelination, MOG-induced experimental autoimmune encephalomyelitis (EAE), revealed a reduction of microglia and macrophages in inflamed lesions. A phase II clinical study in relapsing-remitting multiple sclerosis (RRMS) patients with a modified fumaric acid ester, BG-12, showed as "proof of principle" a significant reduction in the number of gadolinium enhancing lesions after 24 weeks of treatment as compared to placebo. Further phase III studies have now started to explore the long-term efficacy of FAE. PMID:19721818

  6. Antifungal garcinia acid esters from the fruits of Garcinia atroviridis.

    PubMed

    Mackeen, Mukram M; Ali, Abdul Manaf; Lajis, Nordin Hj; Kawazu, Kazuyoshi; Kikuzaki, Hiroe; Nakatani, Nobuji

    2002-01-01

    Two new garcinia acid derivatives, 2-(butoxycarbonylmethyl)-3-butoxycarbonyl-2-hydroxy-3-propanolide and 1',1"-dibutyl methyl hydroxycitrate, were isolated from the fruits of Garcinia atroviridis guided by TLC bioautography against the fungus Cladosporium herbarum. The structures of these compounds were established by spectral analysis. The former compound represents a unique beta-lactone structure and the latter compound is most likely an artefact of garcinia acid (= hydroxycitric acid). Both compounds showed selective antifungal activity comparable to that of cycloheximide (MID: 0.5 microg/spot) only against C herbarum at the MIDs of 0.4 and 0.8 microg/spot but were inactive against bacteria (Bacillus subtilis, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), other fungi (Alternaria sp., Fusarium moniliforme and Aspergillus ochraceous) including the yeast Candida albicans. PMID:12064729

  7. Fatty Acid Esters of Phloridzin Induce Apoptosis of Human Liver Cancer Cells through Altered Gene Expression

    PubMed Central

    Nair, Sandhya V. G.; Ziaullah; Rupasinghe, H. P. Vasantha

    2014-01-01

    Phloridzin (phlorizin or phloretin 2?-O-glucoside) is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin) using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases II? activity that might induce G0/G1 phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA) ester of phloridzin was selected for gene expression analysis using RT2PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2), growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR) and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK), cell cycle machinery (CDKs, TERT, TOP2A, TOP2B) as well as epigenetics regulators (HDACs). These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects mediated through the attenuated expression of several key proteins involved in cell cycle regulation, DNA topoisomerases II? activity and epigenetic mechanisms followed by cell cycle arrest and apoptosis. PMID:25229655

  8. Fatty acid esters of phloridzin induce apoptosis of human liver cancer cells through altered gene expression.

    PubMed

    Nair, Sandhya V G; Ziaullah; Rupasinghe, H P Vasantha

    2014-01-01

    Phloridzin (phlorizin or phloretin 2'-O-glucoside) is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin) using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases II? activity that might induce G0/G1 phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA) ester of phloridzin was selected for gene expression analysis using RT2PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2), growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR) and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK), cell cycle machinery (CDKs, TERT, TOP2A, TOP2B) as well as epigenetics regulators (HDACs). These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects mediated through the attenuated expression of several key proteins involved in cell cycle regulation, DNA topoisomerases II? activity and epigenetic mechanisms followed by cell cycle arrest and apoptosis. PMID:25229655

  9. Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-(2-ethylhexyl) phosphoric acid from sulfuric acid medium

    Microsoft Academic Search

    Xiaowei HUANG; Jianning LI; Zhiqi LONG; Yongqi ZHANG; Xiangxin XUE; Zhaowu ZHU

    2008-01-01

    The extraction of Nd3+ and Sm3+, including the extraction and stripping capability as well as the separation effect of Nd3+ or Sm3+, from a sulfuric acid medium, by mixtures of di-(2-ethylhexyl) phosphoric acid (HDEHP, H2A2(0)) and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (HEH\\/EHP, H2L2(0)) were studied. The distribution ratios and synergistic coefficients of Nd3+ and Sm3+ in different acidities were also

  10. Synthesis and physical properties of isostearic acids and their esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saturated branched-chain fatty acids (sbc-FAs) are found as minor constituents in several natural fats and oils. Sbc-FAs are of interest since they have lower melting points than their linear counterparts and exhibit good oxidative stability; properties that make them ideally suited in a number of ...

  11. Simple and convenient synthesis of esters from carboxylic acids and alkyl halides using tetrabutylammonium fluoride.

    PubMed

    Matsumoto, Kouichi; Shimazaki, Hayato; Miyamoto, Yu; Shimada, Kazuaki; Haga, Fumi; Yamada, Yuki; Miyazawa, Hirotsugu; Nishiwaki, Keiji; Kashimura, Shigenori

    2014-01-01

    A simple and convenient method has been developed for the synthesis of esters from the corresponding carboxylic acids and alkyl halides by using a stoichiometric amount of tetrabutylammonium fluoride (Bu?NF) as the base. The reaction of carboxylic acids and a Bu?NF/THF solution in DMF or THF as the solvent generates carboxylate ions in situ. The carboxylate ions thus generated and accumulated are highly reactive. They are then allowed to react with alkyl halides as the electrophiles, and afford the corresponding esters in moderate to good yields. The reaction without Bu?NF does not afford any product; therefore, Bu?NF seems to play an important role as the base in these reactions. A bulky countercation such as the tetrabutylammonium cation seems to increase the reactivity of the carboxylate ions in the solution phase. PMID:24770480

  12. Effects of caffeic acid phenethyl ester on cerebral cortex: structural changes resulting from middle cerebral artery ischemia reperfusion.

    PubMed

    Cengiz, N; Colakoglu, N; Kavakli, A; Sahna, E; Parlakpinar, H; Acet, A

    2007-01-01

    Overproduction of free radicals is important in the pathogenesis of the cerebral damage induced by ischemia reperfusion. Caffeic acid phenethyl ester, an active component of propolis extract, exhibits antioxidant properties. The study was carried out in 16 male Wistar albino rats, divided into two groups: ischemia reperfusion and ischemia reperfusion with caffeic acid phenethyl ester. The middle cerebral artery was occluded for 60 min with an intraluminal suture, followed by 24-h reperfusion. In this study, widespread infarcted areas, red neurons (eosinophilic degeneration), pyknotic cells, vacuolization and neuroglial cell infiltration were observed in the cerebral cortex in the ischemia reperfusion group. In the caffeic acid phenethyl ester group, slightly infarcted areas were observed and neuroglial cell infiltration was not determined. Congestion of choroid plexus and pia mater was found more severe in the ischemia reperfusion group than in the caffeic acid phenethyl ester group. In the caffeic acid group, neuroglial cell activation was rare. Vacuolization, an indication of brain edema, was prevented by caffeic acid phenethyl ester. In the present study, we showed that pre-treatment with a single i.p. injection of caffeic acid phenethyl ester at 50 microM/kg dose reduced the structural changes. PMID:17416107

  13. New fatty acid, aromatic ester and monoterpenic benzyl glucoside from the fruits of Withania coagulans Dunal.

    PubMed

    Ali, Abuzer; Jameel, Mohammad; Ali, Mohammed

    2015-07-01

    The fruits of Withania coagulans Dunal (family: Solanaceae) are sweet, sedative, emetic, alterative and diuretic; used to treat asthma, biliousness, strangury, wounds, dyspepsia, flatulent colic, liver complaints and intestinal infections in the indigenous system of medicine. Phytochemical investigation of the methanolic extract of W. coagulans fruits led to the isolation of a new fatty acid, an aromatic ester and a monoterpenic benzyl glucoside characterised as n-octatriacont-17-enoic acid (3), geranilan-10-olyl dihydrocinnamoate (4) and geranilan-8-oic acid-10-olyl salicyloxy-2-O-?-d-glucofuranosyl-(6??1?)-O-?-d-glucofuranosyl-6?-n-octadec-9?',11?'-dienoate (5) along with two known fatty acids, n-dotriacont-21-enoic acid (1) and n-tetratriacontanoic acid (2). The structures of isolated phytoconstituents were established on the basis of 1D and 2D NMR, FT-IR, UV, and MS data and chemical means. PMID:25674818

  14. One-Pot Synthesis of Esters of Cyclopropane Carboxylic Acids via Tandem Vicarious Nucleophilic Substitution-Michael Addition Process.

    PubMed

    M?kosza, Mieczys?aw; Bester, Karol; Cmoch, Piotr

    2015-06-01

    ?-Chlorocarbanions generated via base-induced vicarious nucleophilic substitution reaction of alkyl dichloroacetates with nitroarenes react with Michael acceptors to give esters of cyclopropane carboxylic acids substituted with p-nitroaromatic rings. PMID:25950949

  15. Synthesis of phenyldithioglyoxalic acid and its esters. A route to a-ketodithioacid derivatives

    Microsoft Academic Search

    Jayalakshmi Ramachandran; D. V. Ramana; S. R. Ramadas; C. N. Pillai

    1980-01-01

    A novel route has been developed for the direct synthesis of the hitherto unknowna-ketodithioacid. Benzaldehyde has been treated with carbon disulphide in the presence of potassium cyanide, thereby making\\u000a the intermediate carbanion Ph-C(OH)CN to add on to carbon disulphide eventually leading to thea-ketodithioacid. The methyl and ?-carboxypropyl esters of this acid have also been prepared.

  16. Effects of phthalic acid esters (PAEs) on the neonate and aspects of teratogenic actions.

    PubMed Central

    Thomas, J A; Wienckowski, D B; Gillies, B A; Thomas, M J; Youkilis, E J

    1986-01-01

    A review of the literature reveals that several different phthalic acid esters (PAEs) are capable of causing testicular damage. Phthalate-induced zinc deficiency is consistent with germinal epithelial damage. Among experimental animals, mice perhaps show the greatest sensitivity to phthalate-induced terata, but high doses/exposure are required. Little toxicologic information is available with regard to phthalate-induced effects upon the neonate. PMID:3709448

  17. Enantiomeric Separation of (±)Amino Acid Esters on (?)-Phenylurea Chiral Stationary Phase

    Microsoft Academic Search

    Kwang-Pill Lee; Hyun-Bong Lee; Young Cheol Lee; Seong-Ho Choi; Jae Jeong Ryoo; Jung Hag Park

    1999-01-01

    The 3,5-dinitrobenzoyl (±)-amino acid esters were successfully resolved on (?)-phenylurea chiral stationary phases (CSPs) in a normal phase mode by high-performance liquid chromatography (HPLC). The alcohols used for esterification were methanol, ethanol, and n-propanol. The effects of esterification were studied via retention and optical resolution. The solvent and its concentration effect on enantioselectivity have been investigated based on the binary

  18. Phthalic acid esters found in municipal organic waste: enhanced anaerobic degradation under hyper-thermophilic conditions

    Microsoft Academic Search

    H. hartmann; B. k. Ahring

    Abstract Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds,and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2- ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more,than half of the threshold value for the use as fertilizer on agricultural soil in Denmark. Analysis of DEHP in samples before

  19. Bromination of tert Butyl Esters of 7?-Chloro and 7-Alkylidenedeacetoxycephalosporanic Acid Sulfones

    Microsoft Academic Search

    M. Vorona; G. Veinberg; I. Turovskis; E. Lukevics

    2005-01-01

    The action of N-bromosuccinimide on tert-butyl esters of 7?-chloro- and 7-alkylidenedeacetoxycephalosporanic acid sulfones upon irradiation with visible light leads to the formation of a mixture of the product of allylic bromination of the 3-methyl group, namely, 3-bromomethyldeacetoxycephalosporanate, and the product of replacement of a proton at C(2) in the latter, namely, 2-bromo-3-bromomethyldeacetoxycephalosporanate. Small amounts of E-isomers were also obtained in

  20. L-Methionine Methyl Ester Hydrochloride as a Corrosion Inhibitor of Iron in Acid Chloride Solution

    Microsoft Academic Search

    B. Hammouti; M. Taleb; M. Brighli; S. Kertit; A. Aouniti

    1995-01-01

    Some aminoester organic compounds were tested as corrosion inhibitors for iron in molar hydrochloric acid (HCl) by mass-loss and electrochemical polarization methods. Both techniques gave the same order of inhibition. Comparison of results among those aminoesters showed L-methionine methyl ester (METOCHâ) was the best inhibitor. Its inhibition efficiency (E%) reached a maximum value of 95% at 10⁻² M. Polarization measurements

  1. Control of the phytopathogen Botrytis cinerea using adipic acid monoethyl ester

    Microsoft Academic Search

    Begonya Vicedo; María de la O Leyva; Víctor Flors; Ivan Finiti; Gemma del Amo; Dale Walters; Maria Dolores Real; Pilar García-Agustín; Carmen González-Bosch

    2006-01-01

    The in vitro and in vivo antifungal activity of adipic acid monoethyl ester (AAME) on the necrotrophic pathogen Botrytis cinerea has been studied. This chemical effectively controlled this important phytopathogen, inhibited spore germination and mycelium development at non-phytotoxic concentrations. The effectiveness of AAME treatment is concentration-dependent and influenced by pH. Spore germination in the presence of AAME is stopped at

  2. Determination of physicochemical properties of some fatty acid methyl esters by gas liquid chromatography

    Microsoft Academic Search

    Sajid Husain; P. Nageswara Sarma; G. Y. S. K. Swamy; K. Sita Devi

    1993-01-01

    Physicochemical data such as vapor pressures (p0), heats of vaporization (?Hv), activity coefficents at infinite dilution (??) and excess partial molar entropy (?S\\u000a e\\u000a 0\\u000a ) are considered important for conducting unit processes and designing reactor equipment. Scanty information regarding such\\u000a data is available in the literature for the higher fatty acid methyl esters. The objective of this research was

  3. Misidentification of soil bacteria by fatty acid methyl ester (FAME) and BIOLOG analyses

    Microsoft Academic Search

    N. Oka; P. G. Hartel; O. Finlay-Moore; J. Gagliardi; D. A. Zuberer; J. J. Fuhrmann; J. S. Angle; H. D. Skipper

    2000-01-01

    Fatty acid methyl ester (FAME) analysis is commonly used by soil scientists as a sole method for identifying soil bacteria.\\u000a We observed discrepancies with this method for identifying certain species of bacteria. Therefore, we used carbon substrate\\u000a oxidation patterns (BIOLOG) and some simple physical and chemical tests to determine the extent of these discrepancies. Identification\\u000a with FAME profiles gave false

  4. Esters of Indole-3-Acetic Acid from Avena Seeds 1

    PubMed Central

    Percival, Frank W.; Bandurski, Robert S.

    1976-01-01

    The present studies showed that about 80% of the indole-3-acetic acid extractable from Avena kernels by aqueous acetone was esterified to polymers precipitable by ammonium sulfate and ethanol or acetone. The polymers were positively charged, being adsorbed to cation exchange columns at a pH of 3, or below, and eluted at a pH greater than 4. The polymers were heterogeneous with respect to size, about 5,000 to 20,000 daltons, and charge, exhibiting apparent pKa values of 4.2 and 4.7. The polymer fractions contained esterified IAA, anthrone-reactive material that liberated glucose upon acid hydrolysis, phenolic compounds, and peptidic material with a high proportion of hydrophobic amino acids. Since the esterified IAA was unstable, establishing polymer purity was not possible, and the designation IAA-glucoprotein fraction was adopted. Dehusked Avena kernels contained 8 mg/kg total IAA of which 5.5% was free and 94.5% esterified. IAA bound through a peptidic linkage was present, but in only trace amounts. PMID:16659621

  5. Fatty acid methyl ester (FAME) profiles as a tool to investigate community structure of two agricultural soils

    Microsoft Academic Search

    A. M. Ibekwe; A. C. Kennedy

    1999-01-01

    Soil microbiological parameters may be the earliest predictors of soil quality changes. Recently, molecular techniques such\\u000a as fatty acid methyl ester (FAME) profiles have been used to characterize soil microbial communities. Fatty acid methyl ester\\u000a (FAME) from whole soil may be derived from live cells, dead cells, humic materials, as well as plant and root exudates. Our\\u000a objective was to

  6. Syntheses of Benzo[b]furan-6-carbonitrile and 6-Cyanobenzo[b]furan-2-boronic Acid Pinacol Ester

    PubMed Central

    Williams, John D.; Ding, Xiaoyuan; Nguyen, Son; Vines, Kimberly K.; Peet, Norton P.

    2013-01-01

    6-Cyanobenzo[b]furan-2-boronic acid pinacol ester (10) is a potentially useful 2-point scaffold for the construction of specific compounds or compound libraries with benzofuran cores. Using a per-iodination/de-iodination strategy coupled with a Sonogashira alkynylation and Cu-catalyzed heteroannulation, we have developed a procedure that allows the preparation of benzo[b]furan-6-carbonitrile (9) and 6-cyanobenzo[b]furan-2-boronic acid pinacol ester (10) in gram quantities. PMID:24249920

  7. Enantioselective bacterial hydrolysis of amido esters and diamides derived from (±)-trans-cyclopropane-1,2-dicarboxylic acid.

    PubMed

    Hugentobler, Katharina G; Rebolledo, Francisca

    2014-01-28

    Different optically active amido esters, mixed acid esters, amido acids, and diamides derived from trans-cyclopropane-1,2-dicarboxylic acid were prepared from the commercially available diethyl (±)-trans-cyclopropane-1,2-dicarboxylate. The key step was the Rhodococcus rhodochrous IFO 15564 catalyzed hydrolysis of the corresponding racemic amide. The amidase present in this microorganism showed moderate to high enantioselectivity towards these substrates. In addition a simple and efficient Curtius rearrangement of some of the enzymatically prepared cyclopropanecarboxylic acids allowed us to obtain optically active ?-aminocyclopropanecarboxylic acid derivatives with high yields and enantiomeric excesses. PMID:24292844

  8. Crystal structures and spectroscopic properties of ester amide and diamide of squaric acid with prolinamide

    NASA Astrophysics Data System (ADS)

    Kolev, Tsonko; Seidel, Rüdiger W.; Mayer-Figge, Heike; Spiteller, Michael; Sheldrick, William S.; Koleva, Bojidarka B.

    2009-04-01

    We report the synthesis, spectroscopic and structural elucidation of two prolinamide derivatives of squaric acid, i.e. prolinamide ester amide of squaric acid ethyl ester ( 1) and prolinamide diamide of squaric acid dihydrate ( 2). Both compounds crystallize in non-centrosymmetric space groups, monoclinic P2 1 ( 1) and orthorhombic P2 12 12 1 ( 2), respectively. For first time in the literature the crystal structure of homodiamide of amino acid amide of squaric acid is reported. The data for heterodiamides is also absent. Supramolecular zig-zag chains by hydrogen bonds of H 2N-C dbnd O⋯HNH (3.020 Å) and HNH⋯O dbnd C (Sq) (2.972 Å) types with the participation of amide and squaric acid (Sq) fragments, -C dbnd O-NH 2 and O dbnd C (Sq) are refined in ( 1). A helix supramolecular structure is formed in ( 2) by moderate intermolecular HNH⋯O dbnd C(NH 2) hydrogen bond with length of 2.947 Å. The two crystallographical non-equivalent water molecules stabilized the helix by interactions of types HOH⋯O dbnd C (Sq) (2.917 Å), HOH⋯O dbnd C(NH 2) (2.899 Å), H 2O⋯NH 2(C dbnd O) (2.972 Å), respectively. Optical and magnetic properties are investigated with a view to explain the correlation structure-properties of the newly synthesized molecules.

  9. Ultrasound in fatty acid chemistry: Synthesis of a 1-pyrroline fatty acid ester isomer from methyl ricinoleate

    Microsoft Academic Search

    Marcel S. F. Lie Ken Jie; M. S. K. Syed-Rahmatullah; C. K. Lam; P. Kalluri

    1994-01-01

    A novel 1-pyrroline fatty acid ester isomer [viz. 8-(5-hexyl-1-pyrrolin-2-yl)octanoate] has been synthesized from methyl ricinoleate by two routes with an overall yield of\\u000a 42 and 30%, respectively. Most of the reactions are carried out under concomitant ultrasonic irradiation (20 KHz,ca. 53 watts\\/cm2). Under such a reaction condition, the reaction time is considerably shortened, and product yields are high. Dehydrobromination\\u000a under

  10. Selenium Catalyzed Oxidation of Aldehydes: Green Synthesis of Carboxylic Acids and Esters.

    PubMed

    Sancineto, Luca; Tidei, Caterina; Bagnoli, Luana; Marini, Francesca; Lenardão, Eder J; Santi, Claudio

    2015-01-01

    The stoichiometric use of hydrogen peroxide in the presence of a selenium-containing catalyst in water is here reported as a new ecofriendly protocol for the synthesis of variously functionalized carboxylic acids and esters. The method affords the desired products in good to excellent yields under very mild conditions starting directly from commercially available aldehydes. Using benzaldehyde as a prototype the gram scale synthesis of benzoic acid is described, in which the aqueous medium and the catalyst could be recycled at last five times while achieving an 87% overall yield. PMID:26060915

  11. Triamcinolone acetonide 21-oic acid methyl ester: a potent local antiinflammatory steroid without detectable systemic effects.

    PubMed

    Gorsline, J; Bradlow, H L; Sherman, M R

    1985-01-01

    There have been many previous attempts to prepare glucocorticoid analogs that would have high antiinflammatory activity at the site of application but minimal systemic side effects. In principle, esters of cortoic acids could fulfill these criteria, if they had sufficient affinity for the glucocorticoid receptors but were rapidly hydrolyzed to the inactive acids in the circulation. With this rationale, we have synthesized esters of the 21-oic acid of triamcinolone acetonide (TA, 9 alpha-fluoro-11 beta, 16 alpha, 17 alpha, 21-tetrahydroxy-pregna-1, 4-diene-3,20-dione 16,17-acetonide), a potent synthetic glucocorticoid, in both tritiated and unlabeled forms. The synthesis involves 1) oxidation to the 21-dehydro compound with methanolic cupric acetate, 2) further oxidation to the acid with methylene blue in the presence of KCN at pH 6.5, 3) esterification with diazomethane in the presence of methanol or ethanol, to produce the methyl ester of TA (TAme) or ethyl ester, respectively, and 4) purification of the products by TLC and HPLC. The molecular weights and structures of the esters were established by mass spectrometry and nuclear magnetic resonance. The binding of [3H]TAme to steroid receptors or serum steroid-binding proteins and the in vitro hydrolysis of the ester were evaluated simultaneously, by chromatography on Sephadex LH-20 columns in aqueous buffer. [3H]TAme is bound with high affinity by receptors from human leukemic cells and rat liver. The pattern of competition for this binding is characteristic of glucocorticoid receptors: TA approximately equal to TAme greater than R5020 (a synthetic progestin) approximately equal to aldosterone greater than 5 alpha-dihydrotestosterone. [3H]TAme is not bound detectably by serum steroid-binding proteins and is rapidly hydrolyzed during incubation with serum at 37 C. The acidic product has a very low affinity for the glucocorticoid receptor. Complexes of [3H]TAme with human and rat receptors have sedimentation coefficients of 9-10S in hypotonic buffer containing 20 mM Na2MoO4 and approximately 4S in hypertonic, molybdate-free buffer. These values of s20,w are similar to those of the oligomeric and monomeric forms, respectively, of the same receptors labeled with [3H]TA, and of mammalian steroid receptors, in general. The antiinflammatory activity of TAme in rats is comparable to that of prednisolone, but the ester is devoid of the side effects associated with prednisolone treatment (suppression of thymic weight and of serum corticosterone concentration). These bioassay data and the high affinity of the ester for human glucocorticoid receptors suggest that TAme may eventually be useful clinically, as a loc PMID:3855256

  12. Synthesis, primary photophysical and antibacterial properties of naphthyl ester cinoxacin and nalidixic acid derivatives.

    PubMed

    Vargas, Franklin; Zoltan, Tamara; Rivas, Carlos; Ramirez, Alvaro; Cordero, Tulynan; Díaz, Yrene; Izzo, Carla; Cárdenas, Ylec M; López, Verónica; Gómez, Lubimar; Ortega, Jessenia; Fuentes, Alberto

    2008-08-21

    We have synthesized two naphthyl ester quinolone derivates and determined their ability to generate reactive oxygen species (ROS) such as (1)O(2), ()OH, H(2)O(2) upon photolysis with UV-A light. The ability of cinoxacin (1) and nalidixic acid (2), and their naphthyl ester derivatives (3 and 4) to generate a dose-dependent amount of singlet oxygen and ROS (()(-)O(2), ()OH) in cell-free systems was detected by histidine assay and by luminol-enhanced chemiluminescence (LCL), respectively. Their electronic absorption and emission spectra were quantified and their photostability was determined. Their tendency to generate peroxidic derivative species showed the following order: 3>4; in contrast, their ability to generate singlet oxygen was 4>3 and these were better sensitizers than their parent quinolones 1 and 2. The antibacterial activity in darkness and under irradiation of compounds 3 and 4 was tested on Escherichia coli and compared with that of their parent compounds. An enhanced antibacterial activity by irradiation of the naphthyl esters of cinoxacin and nalidixic acid on E. coli was observed. PMID:18562206

  13. Neutral and acid retinyl ester hydrolases associated with rat liver microsomes: relationships to microsomal cholesteryl ester hydrolases

    Microsoft Academic Search

    Mohamed Z. Gad; Earl H. Harrison

    We recently reported the presence of a neutral, bile salt-independent retinyl ester hydrolase (REH) activity in rat liver microsomes and showed that it was distinct from the previously studied bile salt-dependent REH and from non- specific carboxylesterases (Harrison, E. H., and M. Z. Gad. 1989. J Biol. Chem. 264: 17142-17147). We have now further characterized the hydrolysis of retinyl esters

  14. Temperature dependence of the dielectric permittivity of acetic acid, propionic acid and their methyl esters: a molecular dynamics simulation study.

    PubMed

    Riniker, Sereina; Horta, Bruno A C; Thijssen, Bram; Gupta, Saumya; van Gunsteren, Wilfred F; Hünenberger, Philippe H

    2012-04-10

    For most liquids, the static relative dielectric permittivity is a decreasing function of temperature, because enhanced thermal motion reduces the ability of the molecular dipoles to orient under the effect of an external electric field. Monocarboxylic fatty acids ranging from acetic to octanoic acid represent an exception to this general rule. Close to room temperature, their dielectric permittivity increases slightly with increasing temperature. Herein, the causes for this anomaly are investigated based on molecular dynamics simulations of acetic and propionic acids at different temperatures in the interval 283-363 K, using the GROMOS 53A6(OXY) force field. The corresponding methyl esters are also considered for comparison. The dielectric permittivity is calculated using either the box-dipole fluctuation (BDF) or the external electric field (EEF) methods. The normal and anomalous temperature dependences of the permittivity for the esters and acids, respectively, are reproduced. Furthermore, in the EEF approach, the response of the acids to an applied field of increasing strength is found to present two successive linear regimes before reaching saturation. The low-field permittivity ?, comparable to that obtained using the BDF approach, increases with increasing temperature. The higher-field permittivity ?' is slightly larger, and decreases with increasing temperature. Further analyses of the simulations in terms of radial distribution functions, hydrogen-bonded structures, and diffusion properties suggest that increasing the temperature or the applied field strength both promote a relative population shift from cyclic (mainly dimeric) to extended (chain-like) hydrogen-bonded structures. The lower effective dipole moment associated with the former structures compared to the latter ones provides an explanation for the peculiar dielectric properties of the two acids compared to their methyl esters. PMID:22383366

  15. Palladium-catalyzed carbonylation of tert-butyl alcohol to esters of iso-valeric acid

    Microsoft Academic Search

    Hongying Zhou; Shijie Lu; Hongqi Li; Jing Chen; Hongxiang Fu; Hanqing Wang

    1997-01-01

    Tert-butyl alcohol was carbonylated to esters of iso-valeric acid in the presence of a tris(dibenzylideneacetone)dipalladium(0)–triphenylphosphine–p-Ts catalytic system without any halogen promoter or other extreme conditions. Typical reaction conditions are: temperature 120–160°C; p(CO)=4.0–7.0 MPa; tert-butyl alcohol\\/ROH\\/Pd=400\\/3280\\/1; [Pd]=4.3×10?3 mol\\/l; Pd\\/PPh3\\/p-Ts=1\\/24\\/65; reaction time 6–24 h. Under these experimental conditions a high yield (98.9%) and selectivity (99.2%) for esters are obtained. The carbonylation of

  16. Characterization of Benthic Microbial Community Structure by High-Resolution Gas Chromatography of Fatty Acid Methyl Esters

    PubMed Central

    Bobbie, Ronald J.; White, David C.

    1980-01-01

    Fatty acids are a widely studied group of lipids of sufficient taxonomic diversity to be useful in defining microbial community structure. The extraordinary resolution of glass capillary gas-liquid chromatography can be utilized to separate and tentatively identify large numbers of fatty acid methyl esters derived from the lipids of estuarine detritus and marine benthic microbiota without the bias of selective methods requiring culture or recovery of the microbes. The gas-liquid chromatographic analyses are both reproducible and highly sensitive, and the recovery of fatty acids is quantitative. The analyses can be automated, and the diagnostic technique of mass spectral fragmentation analysis can be readily applied. Splitless injection on glass capillary gas chromatographic columns detected by mass spectral selective ion monitoring provides an ultrasensitive and definitive monitoring system. Reciprocal mixtures of bacteria and fungi, when extracted and analyzed, showed progressive changes of distinctive fatty acid methyl esters derived from the lipids. By manipulating the environment of an estuarine detrital microbial community with antibiotics and culture conditions, it was possible to produce a community greatly enriched in eucaryotic fungi, as evidenced by scanning electron microscopic morphology. The fatty acid methyl esters from the lipids in the fungus-enriched detritus showed enrichment of the C18 dienoic and the C18 and C20 polyenoic esters. Manipulation of the detrital microbiota that increased the procaryotic population resulted in an absence of large structures typical of fungal mycelia or diatoms, as evidenced by scanning electron microscopy, and a significantly larger proportion of anteiso- and isobranched C15 fatty acid esters, C17 cyclopropane fatty acid esters, and the cis-vaccenic isomer of the C18 monoenoic fatty acid esters. As determined by these techniques, a marine settling community showed greater differences in bacterial as contrasted to microeucaryotic populations when compared with the microbial communities of benthic cores. Images PMID:16345583

  17. Hepatic enzymatic synthesis and hydrolysis of CoA esters of solvent-derived oxa acids.

    PubMed

    Panuganti, Sree D; Penn, Jill M; Moore, Kathleen H

    2003-01-01

    Many ethylene glycol-derived solvents are oxidized to xenobiotic alkoxyacetic acids (3-oxa acids) by hepatic enzymes. The toxicity of these ubiquitous solvents has been associated with their oxa acid metabolites. For many xenobiotic carboxylic acids, the toxicity is associated with the CoA ester of the acid. In this study, related alkoxyacetic acids were evaluated as potential substrates for acyl-CoA synthetases found in mitochondrial, peroxisomal, and microsomal fractions isolated from rat liver. Likewise, chemically synthesized oxa acyl-CoAs were used as substrates for acyl-CoA hydrolases associated with the same rat liver fractions. Activities of the xenobiotic oxygen-substituted substrates were compared with analogous physiologic aliphatic substrates by UV-vis spectrophotometric methods. All of the solvent-derived oxa acids were reasonable substrates for the acyl-CoA synthetases, although their activity was usually less than the corresponding physiologic acid. Acyl-CoA hydrolase activities were decreased compared with acyl-CoA synthetase activities for all substrates, especially for the oxa acyl-CoAs. These studies suggest that these xenobiotic carboxylic acids may be converted to reactive acyl-CoA moieties which will persist in areas of the cell proximal to lipid synthesis, beta-oxidation, protein acylation, and amino acid conjugation. The interaction of these xenobiotic acyl-CoAs with those processes may be important to their toxicity and/or detoxification. PMID:12717739

  18. Enzymatic synthesis of unsaturated fatty acid glucoside esters for dermo-cosmetic applications.

    PubMed

    Bousquet, M P; Willemot, R M; Monsan, P; Boures, E

    1999-06-20

    Unsaturated fatty acid alpha-butylglucoside esters were prepared by enzymatic esterification of alpha-butylglucoside in nonaqueous media. Conditions were firstly optimized using oleic acid as acyl group. Synthesis was possible in several solvents but the presence of water co-product in the medium limited the reaction to a thermodynamic equilibrium corresponding to a maximal conversion yield of 62%. In pure molten substrates, the removal of water under reduced pressure enabled yields superior to 95% to be obtained. Product profiles depended on enzyme origin : whatever the support, immobilized lipase B from Candida antarctica proved to be far more regioselective for the primary hydroxyl group of glucose than immobilized lipase from Rhizomucor miehei. Results obtained could be easily transposed to the acylation of alpha-butylglucoside with a commercial mixture of unsaturated fatty acids containing more than 60% of linoleic acid. The biocatalyst could be recycled more than ten times without any significant activity loss. PMID:10397830

  19. [Determination of 11 fatty acids and fatty acids methyl esters in biodiesel using ultra performance liquid chromatography].

    PubMed

    Li, Yizhe; Bao, Guirong; Wang, Hua

    2008-07-01

    A method for the determination of 11 familiar components in biodiesel was developed using ultra performance liquid chromatography with evaporative light scattering detector (UPLC-ELSD). These components were oleic acid, methyl cis-9-octadecenoate, linoleic acid, methyl linoleate, stearic acid, methyl octadecanoate, methyl linolenate, palmitic acid, methyl hexadecanoate, erucic acid and myristic acid. The sample was dissolved in methanol after extraction from the products. The separation column was an Acquity UPLC BEH Phenyl C18 (100 mm x 2.1 mm, 1.7 microm) and the mobile phase was acetonitrile-water (3:1, v/v). An isocratic elution program was utilized for the separation. The flow rate was 0.3 mL/min and the column temperature was 40 degrees C. The parameters of ELSD were as follows: the plus was 80; the temperature of the drift tube was 45 degrees C; the eluant gas pressure was 172 kPa. The sample was detected by ELSD in only 5 min. The calibration curves of 11 components showed good linearity with the correlation coefficients greater than 0.997. In comparison with other methods, this method is simple, fast, and has a good separation efficiency. The fatty acids and fatty acid methyl esters were separated in one step, thus, the extent of reaction can be confirmed by the determination of their contents. This method can be routinely used for the determination of the fatty acids and fatty acid methyl esters in the reaction products and the final biodiesel. PMID:18959249

  20. Characterization of electron ionization mass spectral (EIMS) fragmentation patterns of chloropropanol esters of palmitic acid using isotope labeling technique.

    PubMed

    Rahn, Anja K K; Yaylayan, Varoujan A

    2014-01-01

    Chloropropanol (CP) esters are a class of thermally-induced toxicants that are mainly formed in refined edible oils. The structural diversity of these esters presents significant analytical challenges which have often been overcome through analysis of their corresponding free alcohols after a hydrolysis step. Mass spectrometry-based methodologies incorporating characteristic fragmentation patterns of particular isomers of CP esters greatly facilitates their identification. The electron ionization mass spectra (EIMS) of various isomers of synthetic and commercially available (13)C- and (2)H-labeled CP ester standards of palmitic (C16) and other short chain fatty acids (C3 to C10) were generated and analyzed using GC/MS. Short chain CP esters were synthesized by reacting their respective acid anhydrides with the corresponding 3-chloro- and 2-chloro- propanediols in addition to 1,3-dichloro- and 1,2-dichloropropanols. Five fragmentation pathways were identified. Four of the five pathways, such as ?-cleavage, McLafferty rearrangement, ?-H rearrangement and cyclic acyloxonium ion formation, were characteristic of CP mono- and diesters. The remaining pathway generating chloronium ion was found only in dichlorinated isomers. The proposed fragmentation pathways for the palmitic acid esters were confirmed through the use of (13)C- and (2)H-labeled CP ester standards of palmitic acid, and the generality of identified fragmentation patterns was confirmed through the identification of equivalent ions in the mass spectra of short chain fatty acids (C3 to C16). Characteristic ions that were identified in this study retaining the chlorine atom in their structures can be considered as potential markers for the presence of CP esters. PMID:25213450

  1. Synthesis and Biological Evaluation of Novel Mono Acid Esters Derived from the Constituents of Urtica pilulifera.

    PubMed

    I Husein, Ahmad; J Jondi, Waheed; A Zatar, Nidal; S Ali-Shtayeh, Mohammed

    2014-01-01

    New mono acid esters have been synthesized from the reaction of benzoic acid and mono-hydroxybenzoic acids with 2-phenoxyethanol separated from Urtica pilulifera, characterized, and screened for possible antioxidant, antifungal, antimicrobial and anticancer activities. These phenolic acid esters gave various degrees of free radical scavenging, but the values were lower than that of ?-tocopherol. The concentrations of the tested compounds needed to reduce DPPH absorption by 50% at 517 nm were nearly in the range of 900-1100 µg/mL. While for ?-tocopherol was 40 µg /mL. The compounds were tested in-vitro against six bacterial species which are known to cause dermic and mucosal infections in human. 2-phenoxyethyl benzoate showed significant activity in the range of 30% against P. aeruginosa to 70% against E. coli compared with the activity of Streptomycin. On the other hand 2-phenoxyethyl 2-hydroxybenzoate reveals 70% of gentamicin against K. pneumoniae. The tested compounds also showed complete inhibition at a concentration less than 37.5 µg/mL against M. canis and less than 50 µg/mL against T. rubrum. 2-phenoxyethyl 4-hydroxybenzoate showed considerable activity against MCF-7 with IC50 is less than 62.5 µg/mL. PMID:25587305

  2. Synthesis and Biological Evaluation of Novel Mono Acid Esters Derived from the Constituents of Urtica pilulifera

    PubMed Central

    I. Husein, Ahmad; J. Jondi, Waheed; A. Zatar, Nidal; S. Ali-Shtayeh, Mohammed

    2014-01-01

    New mono acid esters have been synthesized from the reaction of benzoic acid and mono-hydroxybenzoic acids with 2-phenoxyethanol separated from Urtica pilulifera, characterized, and screened for possible antioxidant, antifungal, antimicrobial and anticancer activities. These phenolic acid esters gave various degrees of free radical scavenging, but the values were lower than that of ?-tocopherol. The concentrations of the tested compounds needed to reduce DPPH absorption by 50% at 517 nm were nearly in the range of 900-1100 µg/mL. While for ?-tocopherol was 40 µg /mL. The compounds were tested in-vitro against six bacterial species which are known to cause dermic and mucosal infections in human. 2-phenoxyethyl benzoate showed significant activity in the range of 30% against P. aeruginosa to 70% against E. coli compared with the activity of Streptomycin. On the other hand 2-phenoxyethyl 2-hydroxybenzoate reveals 70% of gentamicin against K. pneumoniae. The tested compounds also showed complete inhibition at a concentration less than 37.5 µg/mL against M. canis and less than 50 µg/mL against T. rubrum. 2-phenoxyethyl 4-hydroxybenzoate showed considerable activity against MCF-7 with IC50 is less than 62.5 µg/mL. PMID:25587305

  3. Antiandrogenic activity of anthranilic acid ester derivatives as novel lead structures to inhibit prostate cancer cell proliferation.

    PubMed

    Roell, Daniela; Rösler, Thomas W; Degen, Stephanie; Matusch, Rudolf; Baniahmad, Aria

    2011-06-01

    A plant extract from the fruits of saw palmetto, which is currently used to treat the androgen-dependent benign prostatic hyperplasia and PCa, served as source for new structure variants. We investigated the antiandrogenic potential of an ethanolic total extract and one of its main aromatic components anthranilic acid. An androgen receptor-antagonistic (antiandrogenic) effect of the extract was evident, and although anthranilic acid itself revealed no remarkable effect, its methyl ester, methyl anthranilate, exhibited antiandrogenic potential. Based on this chemical structure, we synthesized and investigated the antiandrogenic activity of four AnA ester derivatives, which were either novel or only little described in literature. These AnA esters inhibit the androgen-dependent transactivation of both the wild-type (wt) androgen receptor and the androgen receptor point mutant T877A, which often occurs in refractory PCa. Moreover, they inhibit the androgen receptor-induced expression of the endogenous prostate-specific antigen. Importantly, AnA esters repress the growth of human PCa cells. Deletion analyses of androgen receptor propose that the antiandrogenic effect of anthranilic acid esters is mediated by the ligand-binding domain, most likely through direct binding, without affecting androgen receptor protein levels. Taken together, the data suggest antiandrogenic potential of anthranilic acid ester derivatives, which can serve as lead structures for novel antiandrogens. PMID:21439024

  4. QTL for phytosterol and sinapate ester content in Brassica napus L. collocate with the two erucic acid genes.

    PubMed

    Amar, Samija; Ecke, Wolfgang; Becker, Heiko C; Möllers, Christian

    2008-05-01

    Improving oil and protein quality for food and feed purposes is an important goal in rapeseed (Brassica napus L.) breeding programs. Rapeseed contains phytosterols, used to enrich food products, and sinapate esters, which are limiting the utilization of rapeseed proteins in the feed industry. Increasing the phytosterol content of oil and lowering sinapate ester content of meal could increase the value of the oilseed rape crop. The objective of the present study was to identify quantitative trait loci (QTL) for phytosterol and sinapate ester content in a winter rapeseed population of 148 doubled haploid lines, previously found to have a large variation for these two traits. This population also segregated for the two erucic acid genes. A close negative correlation was found between erucic acid and phytosterol content (Spearman's rank correlation, r(s) = -0.80**). For total phytosterol content, three QTL were detected, explaining 60% of the genetic variance. The two QTL with the strongest additive effects were mapped on linkage groups N8 and N13 within the confidence intervals of the two erucic acid genes. For sinapate ester content four QTL were detected, explaining 53% of the genetic variance. Again, a close negative correlation was found between erucic acid and sinapate ester content (r(s) = -0.66**) and the QTL with the strongest additive effects mapped on linkage groups N8 and N13 within the confidence intervals of the two erucic acid genes. The results suggests, that there is a pleiotropic effect of the two erucic acid genes on phytosterol and sinapate ester content; the effect of the alleles for low erucic acid content is to increase phytosterol and sinapate ester content. Possible reasons for this are discussed based on known biosynthetic pathways. PMID:18335203

  5. Lysosomal acid lipase deficiency: diagnosis and treatment of Wolman and Cholesteryl Ester Storage Diseases.

    PubMed

    Porto, Anthony F

    2014-09-01

    Lysosomal acid lipase (LAL) is responsible for the hydrolysis of cholesterol esters and triglycerides. LAL is coded by the LIPA gene on chromosome 10q23.31. Its deficiency leads to two autosomal recessive disorders, Wolman disease (WD) and Cholesteryl Ester Storage Disease (CESD). WD has an estimated incidence of 1 in 500,000 live births and is the result of a complete loss of LAL and presents in infancy with vomiting, diarrhea, poor weight gain and hepatomegaly subsequently leading to death. CESD is the result of partial loss of LAL and its presentation is more variable. Patients may be asymptomatic or present with nonspecific gastrointestinal symptoms, hepatomegaly, elevated transaminases and dystipidemia which may be confused with the diagnosis of Non-alcoholic Fatty Liver Disease. CESD is currently underdiagnosed and has an estimated prevalence as high as I in 40,000 individuals. Radiologic findings in WD is calcification of the adrenal glands. Hepatomegaly is noted on CT scan in both WD and CESD. MRI may demonstrate accumulation of cholesterol esters and may be useful to study effects of potential medical therapies. The diagnosis of WD and CESD is based on LIPA gene sequencing and the measurement of LAL levels in peripheral blood leukocytes. Treatment of LAL deficiency is currently limited to control of cholesterol levels and to prevent premature atherosclerosis. Use of enzyme replacement therapy with recombinant human LAL in short-term studies has shown to be safe and effective. PMID:25345094

  6. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

  7. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

  8. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

  9. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

  10. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Diacetyl tartaric acid esters of mono- and diglycerides of edible...or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food...Agents § 582.4101 Diacetyl tartaric acid esters of mono- and diglycerides of...

  11. Synthesis of 5-arylpyrimidine-2-carboxylic acids and the liquid-crystal characteristics of their aryl esters

    SciTech Connect

    Mikhaleva, M.A.; Kolesnichenko, G.A.; Rubina, K.I.; Gol'dberg, Yu.Sh.; Savel'ev, V.A.; Leitis, L.Ya.; Shimanskaya, M.V.; Mamaev, V.P.

    1986-09-01

    5-Arylpyrimidine-2-carboxylic acids were synthesized by the hydrolysis of 5-aryl-2-cyanopyrimidines and the oxidation of 5-aryl-2-styrylpyrimidines under the conditions of phase-transfer catalysis. The aryl esters of the acids were obtained, and their liquid-crystal characteristics were studied. The p-substituted aryl esters of 5-phenylpyrimidine-2-carboxylic acid do not exhibit mesomorphism, but the introduction of a butyloxy group at the p position of the phenyl residue leads to the appearance of nematic characteristics. Aryl 5-phenylpyrimidinylcarbonyloxy-benzoates are nematic liquid crystals with a thermally stable meso phase and an existence range of 50-80/sup 0/C.

  12. Electronically Rich N-Substituted Tetrahydroisoquinoline 3-Carboxylic Acid Esters: Concise Synthesis and Conformational Studies

    PubMed Central

    Al-Horani, Rami A.; Desai, Umesh R.

    2012-01-01

    Recent work in our laboratory has shown that the highly substituted, electronically rich 1,2,3,4–tetrahydroisoquinoline–3–carboxylic acid (THIQ3CA) scaffold is a key building block for a novel class of promising anticoagulants (Al-Horani et al. J. Med. Chem. 2011, 54, 6125–6138). The synthesis of THIQ3CA analogs, especially containing specific, electronically rich substituents, has been a challenge and essentially no efficient methods have been reported in the literature. We describe three complementary, glycine donor-based strategies for high yielding synthesis of highly substituted, electronically rich THIQ3CA esters. Three glycine donors studied herein include hydantoin 1, (±)-Boc-?-phosphonoglycine trimethyl ester 2 and (±)-Z-?-phosphonoglycine trimethyl ester 3. Although the synthesis of THIQ3CA analogs could be achieved using either of the three, an optimal, high yielding approach for the desired THIQ3CA esters was best achieved using 3 in three mild, efficient steps. Using this approach, a focused library of advanced N-arylacyl, N-arylalkyl, and bis-THIQ3CA analogs was synthesized. Variable temperature and solvent-dependent NMR chemical shift studies indicated the presence of two major conformational rotamers in 3:1 proportion for N–arylacyl–THIQ3CA analogs, which were separated by a high kinetic barrier of ~17 kcal/mol. In contrast, N–arylalkyl and bis–THIQ3CA variants displayed no rotamerism, which implicates restricted rotation around the amide bond as the origin for high-barrier conformational interconversion. This phenomenon is of major significance because structure-based drug design typically utilizes only one conformation. Overall, the work presents fundamental studies on the synthesis and conformational properties of highly substituted, electronically rich THIQ3CA analogs. PMID:22665943

  13. Molecular Model of trans-3-(9-Anthryl)-2-Propenoic Acid Ethyl Ester

    NSDL National Science Digital Library

    The Featured Molecules this month come from the paper by Nguyen and Weisman on solvent-free Wittig reactions and the stereochemical consequences of crowding in the transition state. The molecules include those pictured in the paper as well as the cis-isomer of 3-(9-anthryl)-2-propenoic acid ethyl ester. All structures were optimized at the B3LPY/6-31G* level. In the case of ethyl cinnamate, the cis-isomer is slightly more stable thermodynamically than the trans isomer, lending further support for the argument that the observed product distribution arises from the energetics of the transition state.

  14. Synthesis and properties of esters of 2-cyano-3,3,3-trifluoropropionic acid

    Microsoft Academic Search

    A. Yu. Sizov; A. F. Kolomiets; A. V. Fokin

    1987-01-01

    1.The high activity of 2-substituted perfluoropropenes with respect to hexamethyl-disilazane was shown and the optimal conditions for the formation of 2-substituted 3,3,3-tri-fluoropropionitriles in these reactions were found.2.The behavior of esters of 2-cyano-3,3,3-trifluoropropionic acid was studied in the reactions of methylation by diazomethane, thiolation by S2Cl2, addition of CF3NO, dehydrofluorination by the Et3N·BF3 complex, condensation with perfluoro-2-methyl propene and methyl perfluoromethacrylate.

  15. Protective effects of caffeic acid phenethyl ester (CAPE) on intestinal damage in necrotizing enterocolitis

    Microsoft Academic Search

    Cuneyt Tayman; Alparslan Tonbul; Ayd?n Kosus; Ibrahim Murat Hirfanoglu; Hacer Haltas; Sema Uysal; Mustafa Mansur Tatli; Fatih Andiran

    Objective  To determine the preventative effect of caffeic acid phenethyl ester (CAPE) in necrotizing enterocolitis (NEC) in an experimental\\u000a rat model of NEC.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Thirty newborn Sprague–Dawley rats were randomly divided into three groups; as NEC, NEC + CAPE and control. NEC was induced\\u000a by enteral formula feeding, subjected to hypoxia–hyperoxia and cold stress. Pups in the NEC + CAPE group were treated with

  16. A Quantitative Kinetic Study of Polysorbate Autoxidation: The Role of Unsaturated Fatty Acid Ester Substituents

    Microsoft Academic Search

    Jia Yao; Dushyanth K. Dokuru; Matthew Noestheden; Bruce A. Kerwin; Janan Jona; Drazen Ostovic; Darren L. Reid

    2009-01-01

    Purpose  To study the role of unsaturated fatty acid ester substituents in the autoxidation of polysorbate 80 using quantitative kinetics.\\u000a \\u000a \\u000a \\u000a Methods  Oxidation kinetics were monitored at 40°C in aqueous solution by tracking head space oxygen consumption using a fiber optic\\u000a oxygen sensor with phase shift fluorescence detection. Radical chain initiation was controlled using an azo-initiator and\\u000a assessed by Hammond’s inhibitor approach, allowing

  17. Identification of Organic Sulfate Esters in d-Limonene Ozonolysis SOA Under Acidic Condition

    NASA Astrophysics Data System (ADS)

    Iinuma, Y.; Mueller, C.; Boege, O.; Herrmann, H.

    2006-12-01

    Secondary organic aerosol (SOA) components from gas phase ozonolysis of d-limonene were investigated in a series of indoor chamber experiments. The compounds smaller than 300 Da were quantified using capillary electrophoresis coupled to electrospray ionisation ion trap mass spectrometry (CE/ESI-ITMS). HPLC coupled to an ESI-TOFMS and an ESI-ITMS was used for structural study of dimmers and oligomers. Only 10% of the produced SOA could be attributed to low molecular weight carboxylic acids (Mw<300). The oxidation products which have molecular weights over 300 were detected regardless of the seed particle acidity but the concentrations of these compounds were much higher for acidic seed particle experiments. Strong signals of the compounds with mass to charge ratios (m/z) 281, 465 and 481 were detected when sulphuric acid was used in the seed particles. These compounds showed a strong fragment of m/z 97 in MS2 or MS3 spectra indicating the presence of sulfate in the structures. HPLC/ESI-TOFMS analysis suggests the elemental compositions of C10H17O7S-, C20H33O10S- and C20H33O11S- for m/z 281, 465 and 481, respectively. Based on MS^{n} and TOFMS results, they are most likely organic sulfate esters, possibly formed by a heterogeneous acid catalyzed reaction of a limonene oxidation product and sulfuric acid in the particle phase. The concentrations of the organic sulfate ester were as high as 3.7 ?gm-3 for m/z 281.

  18. Alkyl esters of hydroxycinnamic acids with improved antioxidant activity and lipophilicity protect PC12 cells against oxidative stress.

    PubMed

    Garrido, Jorge; Gaspar, Alexandra; Garrido, E Manuela; Miri, Ramin; Tavakkoli, Marjan; Pourali, Samaneh; Saso, Luciano; Borges, Fernanda; Firuzi, Omidreza

    2012-04-01

    Hydroxycinnamic acids (HCAs) are phenolic compounds present in dietary plants, which possess considerable antioxidant activity. In order to increase the lipophilicity of HCAs, with the aim of improving their cellular absorption and expansion of their use in lipophilic media, methyl, ethyl, propyl and butyl esters of caffeic acid and ferulic acid have been synthesized. All caffeate esters had a slightly lower DPPH IC(50) (13.5-14.5 ?M) and higher ferric reducing antioxidant power (FRAP) values (1490-1588 mM quercetin/mole [mMQ/mole]) compared to caffeic acid (16.6 ?M and 1398 mMQ/mole, respectively) in antioxidant assays. In contrast, ferulate esters were less active in DPPH (56.3-74.7 ?M) and FRAP assays (193-262 mMQ/mole) compared to ferulic acid (44.6 ?M and 324 mMQ/mole, respectively). Redox properties of HCAs were in line with their antioxidant capacities, so that compounds with higher antioxidant activities had lower oxidation potentials. Measurement of partition coefficients disclosed the higher lipophilicity of the esters compared to parent compounds. All esters of caffeic acid significantly inhibited hydrogen peroxide-induced neuronal PC12 cell death assessed by MTT assay at 5 and 25 ?M. However, caffeic acid, ferulic acid and ferulate esters were not able to protect the cells. In conclusion, these findings suggest that alkyl esterification of some HCAs augments their antioxidant properties as well as their lipophilicity and as a consequence, improves their cell protective activity against oxidative stress. These compounds could have useful applications in conditions where oxidative stress plays a pathogenic role. PMID:22210493

  19. A simplified and efficient method for the analysis of fatty acid methyl esters suitable for large clinical studies

    Microsoft Academic Search

    Athar Masood; Ken D. Stark; Norman Salem

    2005-01-01

    Conventional sample preparation for fatty acid analysis is a complicated, multiple-step process, and gas chromatography (GC) analysis alone can require ? 1 h per sample to resolve fatty acid methyl esters (FAMEs). Fast GC analysis was adapted to human plasma FAME analysis using a modified polyethylene glycol column with smaller internal diameters, thinner stationary phase films, increased carrier gas linear

  20. Regioselective vinylation of kojic acid using acetylenic esters in the presence of triphenylphosphine or tert -butyl isocyanide

    Microsoft Academic Search

    Sakineh Asghari; Maryam Faraji-Najjarkolaee; Mohammad Ahmadipour

    2010-01-01

    \\u000a Abstract  The 1:1 reactive intermediates generated by addition of tert-butyl isocyanide or triphenylphosphine to acetylenic esters were trapped by kojic acid to yield O-vinylated and C-vinylated\\u000a kojic acid, respectively.\\u000a \\u000a \\u000a \\u000a \\u000a Graphical abstract  

  1. Stereoselective Synthesis of cis-2 and trans-2-(Indol-3-yl) Cyclopropyl Amines, Carboxylic Acids, and Esters

    Microsoft Academic Search

    Tilak T. Raj; Maurice R. Eftink

    1998-01-01

    We report a general route for the synthesis of E and Z isomers of indol-3-yl cyclopropyl amines, carboylic acids, and esters. These cyclopropane containing molecules are of interest as conformationally constrained analogues of tryptamine and indole propionic acid, biologically active indoles. The route involves reaction of vinyl indole with ethyl diazoacetate, chromatographic separation of the E and Z stereoisomers of

  2. QSTR studies regarding the ECOSAR toxicity of benzene-carboxylic acid' esters to fathead minnow fish (Pimephales promelas).

    PubMed

    Tarko, Laszlo; Putz, Mihai V; Ionascu, Cosmin; Putz, Ana-Maria

    2014-01-01

    The present work employs 152 benzene-carboxylic acid' esters having computed the toxicity within the range [2.251, 10.222] for fathead minnow fish (Pimephales promelas). Calibration set includes many pairs having very similar chemical structure, size, shape and hydrophilicity, but very different value of ECOSAR toxicity or vice versa. The QSTR study, which uses all esters as calibration set, emphasized a large percent (16.2%) of outliers. In this QSTR study most of the estimated values of toxicity for outliers are much lower than ECOSAR toxicity. The LogP and some aromaticity descriptors are predictors. The best QSTR for esters having low value (< 5.5) of ECOSAR toxicity and the best QSTR for esters having high value (> 5.5) of ECOSAR toxicity are obtained when the number of outliers is very small. These QSTRs are different enough and highlight opposite influences of certain descriptors on toxicity. The results emphasize two possibilities: (a) the esters having low value of ECOSAR toxicity and the esters having high value of ECOSAR toxicity are included in two different classes from the point of view of structure-toxicity relationship and/or (b) many high values of ECOSAR toxicity are wrong. By comparison, a QSTR using experimental values of toxicity against rats for 37 benzene-carboxylic esters included in the same database gives good correlation experimental/computed values of toxicity, the number of outliers is null and the result of validation test is good. PMID:24724900

  3. Maintenance of D-alanine ester substitution of lipoteichoic acid by reesterification in Staphylococcus aureus.

    PubMed Central

    Koch, H U; Döker, R; Fischer, W

    1985-01-01

    Toluene-treated Staphylococcus aureus cells did not synthesize teichoic acid and lipoteichoic acid under the conditions used. The organism displayed, however, a high capacity of incorporating D-[14C]alanine into previously formed polymers. The reaction was dependent on ATP and enhanced by magnesium ions. The incorporation rate into lipoteichoic acid correlated with the rate of loss of alanine ester which occurred through transfer to teichoic acid and base-catalyzed hydrolysis. At pH 6.5 the loss (20% within 4 h) was completely compensated for by reesterification. At pH 7.5 the loss was 60%, but by accelerated incorporation it was reduced to 10%. Incorporation was also enhanced when the original substitution of lipoteichoic acid was lowered by previous growth of S. aureus at high salt concentration. The newly added alanine was randomly distributed along the poly(glycerophosphate) chain. The decreased alanine substitution of lipoteichoic acid after growth at high salt concentration was shown to result from a direct inhibition of alanine incorporation. PMID:4066613

  4. Accuracy, reproducibility, and interpretation of fatty acid methyl ester profiles of model bacterial communities

    USGS Publications Warehouse

    Kidd, Haack S.; Garchow, H.; Odelson, D.A.; Forney, L.J.; Klug, M.J.

    1994-01-01

    We determined the accuracy and reproducibility of whole-community fatty acid methyl ester (FAME) analysis with two model bacterial communities differing in composition by using the Microbial ID, Inc. (MIDI), system. The biomass, taxonomic structure, and expected MIDI-FAME profiles under a variety of environmental conditions were known for these model communities a priori. Not all members of each community could be detected in the composite profile because of lack of fatty acid 'signatures' in some isolates or because of variations (approximately fivefold) in fatty acid yield across taxa. MIDI- FAME profiles of replicate subsamples of a given community were similar in terms of fatty acid yield per unit of community dry weight and relative proportions of specific fatty acids. Principal-components analysis (PCA) of MIDI-FAME profiles resulted in a clear separation of the two different communities and a clustering of replicates of each community from two separate experiments on the first PCA axis. The first PCA axis accounted for 57.1% of the variance in the data and was correlated with fatty acids that varied significantly between communities and reflected the underlying community taxonomic structure. On the basis of our data, community fatty acid profiles can be used to assess the relative similarities and differences of microbial communities that differ in taxonomic composition. However, detailed interpretation of community fatty acid profiles in terms of biomass or community taxonomic composition must be viewed with caution until our knowledge of the quantitative and qualitative distribution of fatty acids over a wide variety of taxa and the effects of growth conditions on fatty acid profiles is more extensive.

  5. Accuracy, Reproducibility, and Interpretation of Fatty Acid Methyl Ester Profiles of Model Bacterial Communities †

    PubMed Central

    Haack, Sheridan Kidd; Garchow, Helen; Odelson, David A.; Forney, Larry J.; Klug, Michael J.

    1994-01-01

    We determined the accuracy and reproducibility of whole-community fatty acid methyl ester (FAME) analysis with two model bacterial communities differing in composition by using the Microbial ID, Inc. (MIDI), system. The biomass, taxonomic structure, and expected MIDI-FAME profiles under a variety of environmental conditions were known for these model communities a priori. Not all members of each community could be detected in the composite profile because of lack of fatty acid “signatures” in some isolates or because of variations (approximately fivefold) in fatty acid yield across taxa. MIDI-FAME profiles of replicate subsamples of a given community were similar in terms of fatty acid yield per unit of community dry weight and relative proportions of specific fatty acids. Principal-components analysis (PCA) of MIDI-FAME profiles resulted in a clear separation of the two different communities and a clustering of replicates of each community from two separate experiments on the first PCA axis. The first PCA axis accounted for 57.1% of the variance in the data and was correlated with fatty acids that varied significantly between communities and reflected the underlying community taxonomic structure. On the basis of our data, community fatty acid profiles can be used to assess the relative similarities and differences of microbial communities that differ in taxonomic composition. However, detailed interpretation of community fatty acid profiles in terms of biomass or community taxonomic composition must be viewed with caution until our knowledge of the quantitative and qualitative distribution of fatty acids over a wide variety of taxa and the effects of growth conditions on fatty acid profiles is more extensive. PMID:16349327

  6. Highly Functionalized 1,2–Diamino Compounds through Reductive Amination of Amino Acid-Derived ?–Keto Esters

    PubMed Central

    Pérez-Faginas, Paula; Aranda, M. Teresa; García-López, M. Teresa; Infantes, Lourdes; Fernández-Carvajal, Asia; González-Ros, José Manuel; Ferrer-Montiel, Antonio; González-Muñiz, Rosario

    2013-01-01

    1,2-Diamine derivatives are valuable building blocks to heterocyclic compounds and important precursors of biologically relevant compounds. In this respect, amino acid-derived ?–keto esters are a suitable starting point for the synthesis of ?,?–diamino ester derivatives through a two-step reductive amination procedure with either simple amines or ?–amino esters. AcOH and NaBH3CN are the additive and reducing agents of choice. The stereoselectivity of the reaction is still an issue, due to the slow imine-enamine equilibria through which the reaction occurs, affording mixtures of diastereoisomers that can be chromatographically separated. Transformation of the ?,?–diamino esters into pyrrolidinone derivatives allows the configuration assignment of the linear compounds, and constitutes an example of their potential application in the generation of molecular diversity. PMID:23308167

  7. N-( p-Ethynylbenzoyl) derivatives of amino acid and dipeptide methyl esters - Synthesis and structural study

    NASA Astrophysics Data System (ADS)

    Eißmann, Frank; Weber, Edwin

    2011-11-01

    A series of N-( p-ethynylbenzoyl) derivatives ( 1-4) of the amino acids glycine and L-alanine as well as the dipeptides glycylglycine and L-alanylglycine has been synthesized via a two-step reaction sequence including the reaction of an appropriate N-( p-bromobenzoyl) precursor with trimethylsilylacetylene followed by deprotection of the trimethylsilyl protecting group, respectively. X-ray crystal structures of the amino acid and dipeptide methyl esters 1-4 are reported. The amide and peptide bonds within each molecular structure are planar and adopt the trans-configuration. The packing structures are governed by N sbnd H⋯O interactions leading to the formation of characteristic strand motifs. Further stabilization results from weaker C sbnd H⋯O and C sbnd H⋯? contacts.

  8. Carotenoids and their fatty acid esters in the petals of Adonis aestivalis.

    PubMed

    Maoka, Takashi; Etoh, Tetsuji; Kishimoto, Sanae; Sakata, Syusaku

    2011-01-01

    Carotenoids and their fatty acid esters were investigated in the petals of Adonis aestivalis by UV-VIS, (1)H-NMR, FAB-MS, and CD spectrometry. (3S,3'S)-astaxanthin (diester: 72.2%, monoester: 13.8%, free: 1.4%) and (3S)-adonirubin (monoester: 13.8%, free: 0.3%) were identified as the major components. The fatty acids esterified with astaxanthin and adonirubin were assigned as C18:0, C18:1, C16:0, C16:1, C14:0, C12:0, and C10:0 from the FAB-MS spectral data. PMID:21263199

  9. An Advanced TALSPEAK Concept Using 2-Ethylhexylphosphonic Acid Mono-2-Ethylhexyl Ester as the Extractant

    SciTech Connect

    Lumetta, Gregg J.; Casella, Amanda J.; Rapko, Brian M.; Levitskaia, Tatiana G.; Pence, Natasha K.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-12-21

    A method for separating the trivalent actinides and lanthanides is being developed using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) as the extractant. The method is based on the preferential binding of the actinides in the aqueous phase by N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), which serves to keep the actinides in the aqueous phase while the lanthanides are extracted into an organic phase containing HEH[EHP]. The process is very robust, showing little dependence upon the pH or the HEH[EHP], HEDTA, and citrate concentrations over the ranges that might be expected in a nuclear fuel recycling plant. Single-stage runs with a 2-cm centrifugal contactor indicate that modifications to the process chemistry may be needed to increase the extraction rate for Sm, Eu, and Gd. The hydraulic properties of the system are favorable to application in centrifugal contactors.

  10. Retention indices, relative response factors, and mass spectra of trifluoroethyl and heptafluorobutyl esters of carboxylic acids determined by capillary GC/MS

    SciTech Connect

    Yu, S.K.-T.; Vrana, R.P.; Green, J.B.

    1990-11-01

    The GC/MS characteristics of carboxylic acid esters prepared from fluorine-containing alcohols were compared to those of methyl esters. The GC retention of 2,2,2-trifluoroethyl (TFE) esters was less than, and 2,2,3,3,4,4,4-heptafluoro-1-butyl (HFB) esters approximately equivalent to that of methyl esters. The peak shape of both TFE and HFB esters was slightly superior to that of methyl esters. Mass spectra of TFE and HFB aliphatic esters show significantly more intense molecular and key fragment ions than those of methyl esters. Also, owing to their significantly higher molecular weights, TFE or HFB ester molecular ions and most fragment ions of interest occur at significantly higher m/z values than most potential interfering ions. The GC retention indices, relative GC/MS total ion current response factors, and 70 eV electron impact mass spectra of about 70 TFE and 70 HFB carboxylic acid esters are reported. Results from analysis of a TFE/HFB esterified petroleum carboxylic acid concentrate are discussed in detail. 26 refs., 17 figs., 3 tabs.

  11. pH- and sugar-induced shape memory hydrogel based on reversible phenylboronic acid-diol ester bonds.

    PubMed

    Meng, Hao; Zheng, Jing; Wen, Xiufang; Cai, Zhiqi; Zhang, Jiawei; Chen, Tao

    2015-03-01

    A simple strategy is provided to construct a novel pH- and sugar-induced shape memory hydrogel based on dynamic phenylboronic acid (PBA)-diol interactions formed by PBA-modified sodium alginate (Alg-PBA) and poly(vinyl alcohol) (PVA). The dynamic PBA-diol ester bonds serve as temporary cross-links and stabilize the deformed shape of the hydrogel. The disassociation of the PBA-diol ester bonds is explored in acidic conditions and aqueous solutions of glucose and fructose, which endow the hydrogel with shape memory performances. PMID:25630431

  12. Dynamic Analysis of Phorbol Esters in the Manufacturing Process of Fatty Acid Methyl Esters from Jatropha curcas Seed Oil

    Microsoft Academic Search

    Kosuke IchihashiDai; Dai Yuki; Hiroshi Kurokawa; Akinori Igarashi; Toshio Yajima; Masami Fujiwara; Katsuhiro Maeno; Shizuo Sekiguchi; Mitsuo Iwata; Hoyoku Nishino

    2011-01-01

    Jatropha curcas seed oil, which is unsuitable as an edible oil but has received attention as a novel vegetable fat and oil resource, contains\\u000a tumor-promoting phorbol esters. Currently, six types of derivatives of 12-deoxy-16-hydroxyphorbol (DHPEs) in J. curcas oil have been identified, and their toxicological safety for humans is being discussed. However, it is reported that most\\u000a DHPEs disappear during

  13. Comparative Subchronic and Chronic Dietary Toxicity Studies on 2,4-Dichlorophenoxyacetic Acid, Amine, and Ester in the Dog

    Microsoft Academic Search

    Jeffrey M. Charles; Dan W. Dalgard; Helen C. Cunny; Ronald D. Wilson; James S. Bus

    1996-01-01

    Forms of 2,4-dichlorophenoxyacetic acid (2,4-D) are herbicides used in the control of a wide variety of broadleaf and woody plants. Subchronic toxicity studies in dogs were conducted on three forms of 2,4-D: the parent form, 2,4-D acid (ACID); 2,4-D dimethylamine salt (DMA); and 2,4-D 2-ethylhexyl ester (2-EHE). The three studies were designed to allow for comparison of the toxicity of

  14. Visible Light Photorelease of Carboxylic Acids via Charge-Transfer Excitation of N-Methylpyridinium Iodide Esters.

    PubMed

    Kunsberg, David J; Kipping, Allison H; Falvey, Daniel E

    2015-07-17

    Iodide contrast sensitization to direct irradiation of charge transfer salts incurs carboxylic acid release via visible light absorption. The photochemical reduction of N-methyl-4-pyridinium iodide esters to release carboxylic acids is examined using (1)H NMR analysis. Photolysis reactions are carried out under mild, biphasic solvent conditions using a household LED lamp. Carboxylic acid release is reported in high yields, and the viability of this method for synthetic chemistry is demonstrated through a macroscale reaction. PMID:26120927

  15. Application of specific response factors in the gas chromatographic analysis of methyl esters of fatty acids with flame ionization detectors

    Microsoft Academic Search

    R. G. Ackman; J. C. Sipos

    1964-01-01

    The relative responses for flame ionization detectors in the analysis of the longer chain fatty acid methyl esters are shown\\u000a to correlate with the theoretical responses based on weight percent content of “active” carbon. While particularly affecting\\u000a estimation of the shorter chain length saturated fatty acids, these corrections have a less marked effect on the estimation\\u000a of unsaturated fatty acids.

  16. Effects of dietary saturated and trans fatty acids on cholesteryl ester synthesis and hydrolysis in the testes of rats.

    PubMed

    Takatori, T; Phillips, F; Privett, O S

    1976-05-01

    Studies were made of the enzymic synthesis and hydrolysis of cholesteryl esters in rat testes. Weanling rats were fed for 14 weeks diets containing 5% by wt of hydrogenated coconut oil (HCO), a concentrate of ethyl elaidate and linolelaidate (TRANS), devoid of essential fatty acids (EFA), or safflower oil (SAFF). Cholesterol esterifying activity was localized in the soluble fraction, and cholesteryl ester hydrolase activity was distributed in both particulate and soluble fractions obtained from tissue homogenates. The optimum pH was 6.0 for esterification and 6.9-7.0 for hydrolysis. Neither esterifying nor hydrolytic activity was affected by freezing and thawing, but both reactions were inhibited by heat or sonication. The animals of both the HCO and TRANS groups had developed an EFA deficiency before they were sacrificed. The EFA deficiency produced upon feeding the HCO diet had no apparent effect on the synthesis and hydrolysis of cholesteryl esters in rat testes. The TRANS diet influenced the development of the testes as judged by their size, and cholesterol esterifying and cholesteryl ester hydrolyzing activities were suppressed in the testes of the animals of this group. A major difference in the effects of the HCO and TRANS diets on the lipids of the tests was the relatively minor amount of eicosatrienoic acid (20:3) and the elevated level of docosapentaenoic acid (22:5) in the cholesteryl esters of the testicular lipids of the TRANS group. PMID:5644

  17. Ultrasound in fatty acid chemistry: synthesis of a 1-pyrroline fatty acid ester isomer from methyl ricinoleate.

    PubMed

    Lie Ken Jie, M S; Syed-Rahmatullah, M S; Lam, C K; Kalluri, P

    1994-12-01

    A novel 1-pyrroline fatty acid ester isomer (viz. 8-5-hexyl-1-pyrrolin-2-yl) octanoate) has been synthesized from methyl ricinoleate by two routes with an overall yield of 42 and 30%, respectively. Most of the reactions are carried out under concomitant ultrasonic irradiation (20 KHz, ca. 53 watts/cm2). Under such a reaction condition, the reaction time is considerably shortened, and product yields are high. Dehydrobromination under concomitant ultrasonic irradiation of methyl 9, 10-dibromo-12-hydroxyoctadecanoate with KOH in EtOH furnishes methyl 12-hydroxy-9-octadecynoate (66%) within 15 min. Hydration of the latter under ultrasound with mercury(II)acetate in aqueous tetrahydrofuran yields exclusively methyl 12-hydroxy-9-oxo-octadecanoate (95%) in 30 min. The hydroxy group in the latter compound is transformed to the azido function via the mesylate, and treatment of the azido-oxo intermediate (methyl 12-azido-9-oxooctadecanoate) with Ph3P under ultrasonic irradiation furnishes the requisite 1-pyrroline fatty acid ester (77%). The same azido-oxo intermediate has also been obtained by the oxidation of methyl 12-azido-9-cis-octadecenoate using benzoquinone and a catalytic amount of Pd(II)chloride in aqueous tetrahydrofuran under concomitant ultrasonic irradiation (90 min) to give the product in 45% yield. The latter reaction does not take place even under prolonged silent stirring of the reaction mixture. PMID:7854016

  18. d-Glucaric Acid Esters\\/Lactones Used in Condensation Polymerization to Produce Hydroxylated Nylons—A Qualitative Equilibrium Study in Acidic and Basic Alcohol Solutions

    Microsoft Academic Search

    Liang Chen; Donald E. Kiely

    1994-01-01

    Direct esterification of d-glucaric acid in acidic methanol solution produced a mixture of four esters\\/lactones: dimethyl d-glucarate (1), methyl d-glucarate 1,4-lactone (2), methyl d-glucarate 6,3-lactone (3), and d-glucaro-1,4:6,3-dilactone (4). The esters\\/lactones described in this study are activated forms of d-glucaric acid useful for condensation polymerization with diamines to produce hydroxyated nylons. Structures of the esterification products were determined using H

  19. Dibenzo-1,5-diazocine-2,6-dione, 2-iminoindolin-3-one and N-(carbamoylmethyl)-aminobenzoic acid ester from aminobenzoic acid by multicomponent reactions

    Microsoft Academic Search

    Manja Grosche; Eberhardt Herdtweck; Wolfgang A. Herrmann

    1998-01-01

    Aminobenzoic acids show different types of multicomponent reactions when treated with a carbonylic component and an isocyanide in an alcoholic solution. Anthranilic acid provides dibenzo-1,5-diazocine-2,6-dione derivatives by a double Ugi four component reaction (U-4CR) or depending on the reaction conditions the U-5C-4CR product, a N-(carbamoylmethyl)anthranilic acid ester. Whereas anthranilic acid reacts hardly with ketones in that kind of multicomponent reaction.

  20. Comparison of anti-Vibrio activities of potassium sorbate, sodium benzoate, and glycerol and sucrose esters of fatty acids.

    PubMed Central

    Beuchat, L R

    1980-01-01

    The effects of fatty acids and their glycerol and sucrose esters, potassium sorbate, and sodium benzoate on growth of Vibrio parahaemolyticus in laboratory media at pH 6.7 were evaluated. The minimum concentrations at which inhibition by esters of glycerol could be detected were lowest for monolaurin (5 microgram/ml) and monocaprin (40 microgram/ml); these concentrations were lower than those observed for inhibition by lauric and capric acids, respectively. Inhibitory action of sucrose caprylate was detected at 40 microgram/ml, whereas sucrose caprate was effective at 100 microgram/ml; sucrose esters of lauric, myristic, and palmitic acids were ineffective at 100 microgram/ml. Potassium sorbate and sodium benzoate inhibited growth at concentrations as low as 30 and 300 microgram/ml, respectively, and enhanced the rate of thermal inactivation of V. parahaemolyticus at slightly higher concentrations. Fatty acid esters of glycerol and sucrose offer potential as perservatives for slightly acid or alkaline low-fat foods which do not lend themselves to the full antimicrobial action of traditional food preservatives such as potassium sorbate and sodium benzoate. PMID:7406487

  1. Melanogenesis-inhibitory saccharide fatty acid esters and other constituents of the fruits of Morinda citrifolia (noni).

    PubMed

    Akihisa, Toshihiro; Tochizawa, Shun; Takahashi, Nami; Yamamoto, Ayako; Zhang, Jie; Kikuchi, Takashi; Fukatsu, Makoto; Tokuda, Harukuni; Suzuki, Nobutaka

    2012-06-01

    Five new saccharide fatty acid esters, named nonioside P (3), nonioside Q (4), nonioside R (8), nonioside S (10), and nonioside T (14), and one new succinic acid ester, butyl 2-hydroxysuccinate (=4-butoxy-3-hydroxy-4-oxobutanoic acid) (31), were isolated, along with 26?known compounds, including eight saccharide fatty acid esters, 1, 2, 5, 6, 7, 9, 12, and 13, three hemiterpene glycosides, 15, 17, and 18, six iridoid glycosides, 21-25, and 27, and nine other compounds, 20, 28, 29, and 32-37, from a MeOH extract of the fruit of Morinda citrifolia (noni). Upon evaluation of these and five other glycosidic compounds, 11, 16, 19, 26, and 30, from M. citrifolia fruit extract for their inhibitory activities against melanogenesis in B16 melanoma cells induced with ?-melanocyte-stimulating hormone (?-MSH), most of the saccharide fatty acid esters, hemiterpene glycosides, and iridoid glycosides showed inhibitory effects with no or almost no toxicity to the cells. These compounds were further evaluated with respect to their cytotoxic activities against two human cancer cell lines (HL-60 and AZ521) and their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. PMID:22700235

  2. Lasiojasmonates A-C, three jasmonic acid esters produced by Lasiodiplodia sp., a grapevine pathogen.

    PubMed

    Andolfi, Anna; Maddau, Lucia; Cimmino, Alessio; Linaldeddu, Benedetto T; Basso, Sara; Deidda, Antonio; Serra, Salvatorica; Evidente, Antonio

    2014-07-01

    In this study, a strain (BL 101) of a species of Lasiodiplodia, not yet formally described, which was isolated from declining grapevine plants showing wedge-shaped cankers, was investigated for its ability to produce in vitro bioactive secondary metabolites. From culture filtrates of this strain three jasmonic acid esters, named lasiojasmonates A-C and 16-O-acetylbotryosphaerilactones A and C were isolated together with (1R,2R)-jasmonic acid, its methyl ester, botryosphaerilactone A, (3S,4R,5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone and (3R,4S)-botryodiplodin. The structures of lasiojasmonates A-C were established by spectroscopic methods as (1R*,2R*,3'S*,4'R*,5'R*)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone, (1R*,2R*,3'S*,4'R*,5'R*,10'R*,12'R*,13'R*,14'S*) and (1R*,2R*,3'S*,4'R*,5'R*,10'S*,12'R*,13'R*,14'S*)-4-(4-hydroxymethyl-3,5-dimethyltetrahydro-furan-2-yloxymethyl)-3,5-dimethyldihydro-2-furanones jasmonates (1, 4 and 5). The structures of 16-O-acetylbotryosphaerilactones A and C were determined by comparison of their spectral data with those of the corresponding acetyl derivatives obtained by acetylation of botryosphaerilactone A. The metabolites isolated, except 4 and 5, were tested at 1mg/mL on leaves of grapevine cv. Cannonau and cork oak using the leaf puncture assay. They were also tested on detached grapevine leaves at 0.5mg/mL and tomato cuttings at 0.1mg/mL. In all phytotoxic assays only jasmonic acid was found to be active. All metabolites were inactive in the zootoxic assay at 50 ?g/mL. PMID:24768282

  3. Evidence of silicic acid leakage to the tropical Atlantic via Antarctic Intermediate Water during Marine Isotope Stage 4

    NASA Astrophysics Data System (ADS)

    Griffiths, James D.; Barker, Stephen; Hendry, Katharine R.; Thornalley, David J. R.; Flierdt, Tina; Hall, Ian R.; Anderson, Robert F.

    2013-06-01

    Antarctic Intermediate Water (AAIW) and Subantarctic Mode Water (SAMW) are the main conduits for the supply of dissolved silicon (silicic acid) from the deep Southern Ocean (SO) to the low-latitude surface ocean and therefore have an important control on low-latitude diatom productivity. Enhanced supply of silicic acid by AAIW (and SAMW) during glacial periods may have enabled tropical diatoms to outcompete carbonate-producing phytoplankton, decreasing the relative export of inorganic to organic carbon to the deep ocean and lowering atmospheric pCO2. This mechanism is known as the "silicic acid leakage hypothesis" (SALH). Here we present records of neodymium and silicon isotopes from the western tropical Atlantic that provide the first direct evidence of increased silicic acid leakage from the Southern Ocean to the tropical Atlantic within AAIW during glacial Marine Isotope Stage 4 (~60-70 ka). This leakage was approximately coeval with enhanced diatom export in the NW Atlantic and across the eastern equatorial Atlantic and provides support for the SALH as a contributor to CO2 drawdown during full glacial development.

  4. Ab initio molecular orbitals study of the conformational preference in alpha-cyano-alpha-fluorophenylacetic acid ester.

    PubMed

    Sahnoun, Riadh; Fujimura, Yuichi; Kabuto, Kuninobu; Takeuchi, Yoshio; Noyori, Ryoji

    2007-10-12

    The origin of conformational preference in alpha-cyano-alpha-fluorophenylacetic acid (CFPA) methyl ester that is a model system of alpha-cyano-alpha-fluoro-p-tolylacetic acid (CFTA) esters was theoretically investigated by means of DFT and MP2 calculations. Two stable conformations having the C-F bond syn and anti to the C=O bond, respectively, were obtained for CFPA methyl ester. A small energy difference (0.9 kcal mol-1 at the MP2(fc)/6-31++G(d,p)) was found between the two conformations. From the molecular orbital analysis based on the Natural Bond Orbital analysis and supported by calculations using the Orbital Deletion Procedure technique, we found that sigma-(sigma*+pi*)(C=O) and sigma-sigma*(Ph) and pi(Ph)-sigma* hyperconjugations are the main factors responsible for the conformational preference. The role of the fluorine atom on the stereogenic center was also clarified. PMID:17880239

  5. Silicic acid biogeochemistry in the Gulf of California: Insights from sedimentary Si isotopes

    NASA Astrophysics Data System (ADS)

    Pichevin, Laetitia; Ganeshram, Raja S.; Reynolds, Ben C.; Prahl, Fredrick; Pedersen, Thomas F.; Thunell, Robert; McClymont, Erin L.

    2012-06-01

    Iron is considered to play a large role in the cycling of Si in Fe-limited regions of the ocean, but little is known about its role in Si biogeochemistry outside these areas. Here, we present published sediment trap data, new nutrient profiles and high resolution sedimentary records (Si isotopes, Biogenic silica%, N% and C%) from the Gulf of California, a non-Fe-limited region, to investigate the history of Si cycling in this highly productive basin. Modern nutrient profiles show that silicic acid in subsurface waters is in excess relative to nitrate and is therefore incompletely utilized during moderate winter upwelling events. Modern data, however, suggest that during intense upwelling episodes, silicic acid is preferentially utilized relative to nitrate by the biota, which we suggest reflects transient iron limitation. Our new ?30Si record from the Guaymas Basin shows dramatic variations at millennial timescales. Low ?30Si values synchronous with Heinrich events are interpreted as resulting from the decline in Si(OH)4 utilization at times of decreased upwelling strength, while nearly complete Si(OH)4 utilization was observed at times of invigorated upwelling and increased opal burial during the Holocene, the Bølling-Allerød and the last glacial period. We attribute the complete utilization of Si(OH)4 to the occurrence of transient Fe limitation at these times. Our study highlights the importance of Fe limitation on Si and C cycling in coastal upwelling regions and suggests that upwelling dynamics, in combination with Fe availability, have the potential to modulate marine Si distribution and opal burial even at short timescales.

  6. Effect of silicic acid on arsenate and arsenite retention mechanisms on 6-L ferrihydrite: A spectroscopic and batch adsorption approach

    PubMed Central

    Gao, Xiaodong; Root, Robert A.; Farrell, James; Ela, Wendell; Chorover, Jon

    2014-01-01

    The competitive adsorption of arsenate and arsenite with silicic acid at the ferrihydrite-water interface was investigated over a wide pH range using batch sorption experiments, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, extended X-ray absorption fine structure (EXAFS) spectroscopy, and density functional theory (DFT) modeling. Batch sorption results indicate that the adsorption of arsenate and arsenite on the 6-L ferrihydrite surface exhibits a strong pH-dependence, and the effect of pH on arsenic sorption differs between arsenate and arsenite. Arsenate adsorption decreases consistently with increasing pH; whereas arsenite adsorption initially increases with pH to a sorption maximum at pH 7–9, where after sorption decreases with further increases in pH. Results indicate that competitive adsorption between silicic acid and arsenate is negligible under the experimental conditions; whereas strong competitive adsorption was observed between silicic acid and arsenite, particularly at low and high pH. In-situ, flow-through ATR-FTIR data reveal that in the absence of silicic acid, arsenate forms inner-sphere, binuclear bidentate, complexes at the ferrihydrite surface across the entire pH range. Silicic acid also forms inner-sphere complexes at ferrihydrite surfaces throughout the entire pH range probed by this study (pH 2.8 – 9.0). The ATR-FTIR data also reveal that silicic acid undergoes polymerization at the ferrihydrite surface under the environmentally-relevant concentrations studied (e.g., 1.0 mM). According to ATR-FTIR data, arsenate complexation mode was not affected by the presence of silicic acid. EXAFS analyses and DFT modeling confirmed that arsenate tetrahedra were bonded to Fe metal centers via binuclear bidentate complexation with average As(V)-Fe bond distance of 3.27 Å. The EXAFS data indicate that arsenite forms both mononuclear bidentate and binuclear bidentate complexes with 6-L ferrihydrite as indicated by two As(III)-Fe bond distances of ~2.92–2.94 and 3.41–3.44 Å, respectively. The As-Fe bond distances in both arsenate and arsenite EXAFS spectra remained unchanged in the presence of Si, suggesting that whereas Si diminishes arsenite adsorption preferentially, it has a negligible effect on As-Fe bonding mechanisms. PMID:25382933

  7. Improved monitoring of female codling moth (Lepidoptera: Tortricidae) with pear ester plus acetic acid in sex pheromone-treated orchards.

    PubMed

    Knight, Alan

    2010-08-01

    The performance of clear delta traps baited with 3.0 mg of pear ester, ethyl (E,Z)-2,4-decadienoate, and 5.0 ml of acetic acid in separate lures was compared with orange delta traps baited with a single lure containing 3.0 mg of both pear ester and the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone) for codling moth, Cydia pomonella (L.), in apple, Malus domestica (Borkhausen). Residual analyses and field tests demonstrated that both the pear ester and acetic acid lures were effective for at least 8 wk. The two trap-lure combinations caught a similar number of total moths in an orchard treated with sex pheromone dispensers during short-term trials in 2008. However, the mean catch of female moths was significantly higher and male moths significantly lower in clear traps baited with pear ester and acetic acid versus orange traps baited with pear ester and codlemone. Season-long studies were conducted with these two trap-lure combinations in orchards treated with (n = 6) and without (n = 7) sex pheromone dispensers during 2009. The two trap-lure combinations caught similar numbers of moths in dispenser-treated orchards. In contrast, total catch was significantly higher (>2-fold) in the orange compared with the clear traps in untreated orchards. The clear caught >6-fold more females than the orange trap in both types of orchards. These studies suggest that deploying clear delta traps baited with pear ester and acetic acid can be an effective monitoring tool for female codling moth and an alternative to codlemone-baited traps in sex pheromone-treated orchards. PMID:22127179

  8. 40 CFR 721.10448 - Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...New Uses for Specific Chemical Substances § 721...methoxy-, methyl ester, reaction products with substituted...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...hydroxymethoxy-, methyl ester, reaction products with...

  9. Evaluation of Peanut Fatty Acid Methyl Ester Sprays, Combustion, and Emissions, for Use in an Indirect Injection Diesel Engine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The paper provides an analysis of 100% peanut fatty acid methyl esters (FAMEs) and peanut FAME/ULSD#2 blends (P20, P35, and P50) in an indirect injection (IDI) diesel engine (for auxiliary power unit applications) in comparison to ultralow sulfur diesel no. 2 (ULSD#2) at various speeds and 100% load...

  10. IN SITU ALKALINE TRANSESTERIFICATION: AN EFFECTIVE METHOD FOR THE PRODUCTION OF FATTY ACID ESTERS FROM VEGETABLE OILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The production of simple alkyl fatty acid esters by 'in situ' transesterification of the acylglycerols present in flaked soybeans by incubation with alkaline alcohol solutions was examined. Commercially produced soy flakes had a hexane-extractable lipid content of 23.9%. Initial experiments showed...

  11. In vitro permeation through porcine buccal mucosa of caffeic acid phenetyl ester (CAPE) from a topical mucoadhesive gel containing propolis

    Microsoft Academic Search

    G. C. Ceschel; P. Maffei; A. Sforzini; S. Lombardi Borgia; A. Yasin; C. Ronchi

    2002-01-01

    Recent studies have shown that propolis has on the oral cavity appreciable antibacterial, antifungal and antiviral actions, as well as anti-inflammatory, anaesthetic and cytostatic properties. In light of these studies, an assessment of the diffusion and permeation of caffeic acid phenetyl ester (CAPE) through porcine buccal mucosa was considered useful as a possible application in the stomatological field. To do

  12. 40 CFR 721.10467 - 2-Propenoic acid, 3-hydroxytricyclo[3.3.1.13,7]dec-1-yl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...identified as 2-propenoic acid, 3-hydroxytricyclo[3.3.1.13,7]dec-1-yl ester (PMN P-03-564; CAS No. 216581-76-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  13. 40 CFR 721.10467 - 2-Propenoic acid, 3-hydroxytricyclo[3.3.1.13,7]dec-1-yl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...identified as 2-propenoic acid, 3-hydroxytricyclo[3.3.1.13,7]dec-1-yl ester (PMN P-03-564; CAS No. 216581-76-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  14. Mild and Rapid Hydroxylation of Aryl/Heteroaryl Boronic Acids and Boronate Esters with N-Oxides

    PubMed Central

    Zhu, Chen; Wang, Rui; Falck, J. R.

    2012-01-01

    Aryl and heteroaryl boronic acids and boronate esters are rapidly, often within minutes, transformed into the corresponding phenols by N-oxides in an open flask at ambient temperature. This transformation has broad compatibility with a variety of functional groups. PMID:22731862

  15. Application of FAME (fatty acid methyl ester) analysis in the numerical taxonomic determination of bacterial guild structure

    Microsoft Academic Search

    Lawrence M. Mallory; Gary S. Sayler

    1984-01-01

    Comparative numerical taxonomic analyses, using fatty acid methyl ester (FAME) profiles and phenetic characteristics, were conducted to examine bacterial guild structure in freshwater sediments. Both approaches were used to examine a subset of 60 OTUs obtained from a previously well characterized microbial community in sediments of a shallow fast flowing stream. For both classifications, greater than 80% of the OTUs

  16. Biodegradable coumaric acid-based poly(anhydride-ester) synthesis and subsequent controlled release.

    PubMed

    Ouimet, Michelle A; Stebbins, Nicholas D; Uhrich, Kathryn E

    2013-08-01

    To overcome drug delivery issues associated with its short half-life in vivo, p-coumaric acid (pCA), a naturally occurring bioactive, has been chemically incorporated into a poly(anhydride-ester) backbone through solution polymerization. Nuclear magnetic resonance and Fourier transform infrared spectroscopies indicated that pCA was successfully incorporated without noticeable alterations in structural integrity. The polymer's weight-average molecular weight and thermal properties were determined, exhibiting a molecular weight of over 26 000 Da and a glass transition temperature of 57 °C. In addition, in vitro hydrolytic release studies demonstrated pCA release over 30 d with maintained antioxidant activity, demonstrating the polymer's potential as a controlled release system. PMID:23836606

  17. [Comparative assessment of Cladophora, Spirogyra and Oedogonium biomass for the production of fatty acid methyl esters].

    PubMed

    Haq, I; Muhammad, A; Hameed, U

    2014-01-01

    The use of alternative fuels for the mitigation of ecological impacts by use of diesel has been focus of intensive research. In the present work, algal oils extracted from cultivated biomass of Cladophora sp., Spirogyra sp. and Oedogonium sp. were evaluated for the lipase-mediated synthesis of fatty acid monoalkyl esters (FAME, biodiesel). To optimize the transesterification of these oils, different parameters such as the alkyl group donor, reaction temperature, stirring time and oil to alcohol ratio were investigated. Four different alcohols i.e. methanol, ethanol, n-propanol and n-butanol were tested as alkyl group donor for the biosynthesis FAME and methanol was found to be the best. Similarly, temperature 50 C and stirring time of 6 h were optimized for the transesterification of oils with methanol. The maximum biodiesel conversions from Cladophora (75.0%), Spirogyra (87.5%) and Oedogonium (92.0%) were obtained when oil to alcohol ratio was 1 : 8. PMID:25272756

  18. Future opportunities in preventing ototoxicity: Caffeic acid phenethyl ester may be a candidate (Review).

    PubMed

    Akyol, Sumeyya; Isik, Bunyamin; Altuntas, Aynur; Erden, Gonul; Cakmak, Ozlem; Kur?unlu, S Fatih; Adam, Bahattin; Akyol, Omer

    2015-09-01

    Caffeic acid phenethyl ester (CAPE) is an important active component of propolis, which is derived from honeybee hives. It has received increasing attention in a variety of medical and pharmaceutical research, due to its anti?oxidant, antiproliferative, anti?inflammatory, antiviral and antifungal activity, in addition to its antineoplastic properties. Besides the use of CAPE as an antioxidant and anti?inflammatory agent in a number of in vivo studies of ear disease, its beneficial effects have been reported in the treatment of cancer, arthritis, allergies, heart disease, diabetes, kidney disease, liver disease and neurological disease. CAPE influences a number of biochemical pathways, as well as several targets involved in ear diseases, in particular, in ototoxicity. The protective effects of CAPE in ototoxicity, which may be induced by a number factors, including lipopolysaccharides, hydrogen peroxide and streptomycin, are evaluated and discussed in the present review. PMID:25975288

  19. Therapeutic potential of caffeic acid phenethyl ester and its anti-inflammatory and immunomodulatory effects (Review)

    PubMed Central

    ARMUTCU, FERAH; AKYOL, SUMEYYA; USTUNSOY, SEYFETTIN; TURAN, FATIME FILIZ

    2015-01-01

    Caffeic acid phenethyl ester (CAPE), a naturally occurring compound isolated from propolis extract, has been reported to have a number of biological and pharmacological properties, exerting antioxidant, anti-inflammatory, anticarcinogenic, antibacterial and immunomodulatory effects. Recent in vivo and in vitro study findings have provided novel insights into the molecular mechanisms involved in the anti-inflammatory and immunomodulatory activities of this natural compound. CAPE has been reported to have anti-inflammatory properties involving the inhibition of certain enzyme activities, such as xanthine oxidase, cyclooxygenase and nuclear factor-?B (NF-?B) activation. Since inflammation and immune mechanisms play a crucial role in the onset of several inflammatory diseases, the inhibition of NF-?B represents a rationale for the development of novel and safe anti-inflammatory agents. The primary goal of the present review is to highlight the anti-inflammatory and immunomodulatory activities of CAPE, and critically evaluate its potential therapeutic effects. PMID:26136862

  20. Intraparticle diffusion limitations in the hydrogenation of monounsaturated edible oils and their fatty acid methyl esters

    SciTech Connect

    Jonker, G.H.; Veldsink, J.W.; Beenackers, A.A.C.M. [Univ. of Groningen (Netherlands). Dept. of Chemical Engineering] [Univ. of Groningen (Netherlands). Dept. of Chemical Engineering

    1998-12-01

    Intraparticle diffusion limitation in the hydrogenation and isomerization of fatty acid methyl esters (FAMEs) and edible oils (triacylglycerol, TAG) in porous nickel catalyst was investigated both under reactive and under inert conditions. Under reactive conditions, the diffusion coefficients were determined from the best fits of the model simulations applying the intrinsic reacting kinetics of monounsaturated FAME hydrogenation to experiments under diffusion limited conditions. Due to the absence of reaction (hydrogenation of double bonds), the obtained effective H{sub z} diffusion coefficient (D{sub e}) with the HPLC technique is volume averaged and thereby determined by the larger intercrystalline pores (<30% of the total pore volume) only. Moreover, D{sub e} measured under reaction conditions reflected the influence of the micropores, resulting in a 10-fold lower value.

  1. Experimental and computational thermochemical study of 2- and 3-thiopheneacetic acid methyl esters.

    PubMed

    Roux, María Victoria; Temprado, Manuel; Notario, Rafael; Chickos, James S; Santos, Ana Filipa L O M; da Silva, Manuel A V Ribeiro

    2007-06-21

    Thiophene-based compounds have widespread use in modern drug design, biodiagnostics, electronic and optoelectronic devices, and conductive polymers. The present study reports an experimental and computational thermochemical study on the relative stabilities of 2- and 3-thiopheneacetic acid methyl esters. The enthalpies of combustion and vaporization were measured by a rotating-bomb combustion calorimeter, Calvet microcalorimetry, and correlation gas chromatography, and the gas-phase enthalpies of formation at T=298.15 K were determined. Standard ab initio molecular orbital calculations at the G3 level were performed, and a theoretical study of the molecular and electronic structure of the compounds studied was carried out. Calculated enthalpies of formation, using atomization and isodesmic reactions are in very good agreement with the experimental results. PMID:17530748

  2. Phase behaviour and formation of fatty acid esters nanoemulsions containing piroxicam.

    PubMed

    Mat Hadzir, Nursyamsyila; Basri, Mahiran; Abdul Rahman, Mohd Basyaruddin; Salleh, Abu Bakar; Raja Abdul Rahman, Raja Noor Zaliha; Basri, Hamidon

    2013-03-01

    Fatty acid esters are long-chain esters, produced from the reaction of fatty acids and alcohols. They possess potential applications in cosmetic and pharmaceutical formulations due to their excellent wetting behaviour at interfaces and a non-greasy feeling when applied on the skin surfaces. This preliminary work was carried out to construct pseudo-ternary phase diagrams for oleyl laurate, oleyl stearate and oleyl oleate with surfactants and piroxicam. Then, the preparation and optimization study via 'One-At-A-Time Approach' were carried out to determine the optimum amount of oil, surfactants and stabilizer using low-energy emulsification method. The results revealed that multi-phase region dominated the three pseudo-ternary phase diagrams. A composition was chosen from each multi-phase region for preparing the nanoemulsions systems containing piroxicam by incorporating a hydrocolloid stabilizer. The results showed that the optimum amount (w/w) of oil for oleyl laurate nanoemulsions was 30 and 20 g (w/w) for oleyl stearate nanoemulsions and oleyl oleate nanoemulsions. For each nanoemulsions system, the amount of mixed surfactants and stabilizer needed for the emulsification to take place was found to be 10 and 0.5 g (w/w), respectively. The emulsification process via high-energy emulsification method successfully produced nano-sized range particles. The nanoemulsions systems passed the centrifugation test and freeze-thaw cycle with no phase failures, and stable for 3 months at various storage temperatures (3°C, 25°C and 45°C). The results proved that the prepared nanoemulsions system cannot be formed spontaneously, and thus, energy input was required to produce nano-sized range particles. PMID:23386307

  3. Phthalic acid esters found in municipal organic waste: enhanced anaerobic degradation under hyper-thermophilic conditions.

    PubMed

    Hartmann, H; Ahring, B K

    2003-01-01

    Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2-ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more than half of the threshold value for the use as fertilizer on agricultural soil in Denmark. Analysis of DEHP in samples before and after large-scale anaerobic digesters revealed higher concentrations of DEHP per kg dry matter in the effluent than in the influent. The concentration of DEHP and DBP (dibutylphthalate) in OFMSW was monitored in the influent and effluent of anaerobic thermophilic (55 degrees C) and hyper-thermophilic (68 degrees C) laboratory-scale reactor systems. In the thermophilic reactors with a hydraulic retention time (HRT) of 15 days 38-70% of DBP was removed, but no consistent removal of DEHP was observed. However, after treatment of the effluent from the thermophilic reactor in a hyper-thermophilic digester (HRT: 5 days) 34-53% of the DEHP content was removed and the DBP removal was increased to further 62-74%. Removal rates (k(h)) of DEHP and DBP were found to be 0.11-0.32 d(-1) and 0.41-0.79 d(-1), which is much higher than in previous investigations. It can be concluded that the higher removal rates are due to the higher temperature and higher initial concentrations per kg dry matter. These results suggest that the limiting factor for DEHP degradation is the bioavailability, which is enhanced at higher temperature and higher degradation of solid organic matter, to which the highly hydrophobic DEHP is adsorbed. The investigated reactor configuration with a thermophilic and a hyper-thermophilic treatment is, therefore, a good option for combining high rate degradation of organic matter with high biogas yields and efficient reduction of the phthalic acid ester contamination. PMID:14531437

  4. The influence of molecular structure of fatty acid monoalkyl esters on diesel combustion

    SciTech Connect

    Schoenborn, Alessandro; Ladommatos, Nicos [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Williams, John; Allan, Robert; Rogerson, John [BP Oil UK Limited, Technology Centre, Whitchurch Hill, Pangbourne, Reading, RG8 7QR (United Kingdom)

    2009-07-15

    The subject of this paper is a series of experiments conducted on a single-cylinder research engine investigating the influence of molecular structure on the combustion behaviour of fatty acid alcohol ester (biodiesel) molecules under diesel engine conditions. The fuels employed in these experiments comprised various samples of pure individual fatty acid alcohol ester molecules of different structure, as well as several mixtures of such molecules. The latter consisted in biodiesel fuels produced by the transesterification of naturally occurring plant oils or animal fat with a monohydric alcohol. It was observed that the molecular structure of the fuel significantly influenced the formation of NO{sub x} and particulate matter and their respective concentration in the exhaust gas. The influence on the formation of NO{sub x} in particular, appeared to be exerted first through the effect which the molecular structure had on the auto-ignition delay occurring after the fuel was injected into the combustion chamber, and second through the flame temperature at which the various molecules burned. The emission of particulates on the other hand showed correlation with the number of double bonds in the fuel molecules for the case of larger accumulation mode particles, and with the boiling point of the fuel samples for the case of the smaller, nucleation mode particles. The effect of ignition delay on the exhaust emissions of these pollutants was isolated by adding the ignition promoting molecule 2-ethylhexyl nitrate to some of the fuel samples in closely specified concentrations, so as to equalise the ignition delay for the relevant fuel samples. The removal of the ignition delay as a main influence on the combustion process enabled the observation of the lesser effects of adiabatic flame temperature. (author)

  5. Isomers and homologues of l-glutamic acid 5- n-butyl ester as promoters of sediment formation in raw soy sauce

    Microsoft Academic Search

    Masahiro Tomita; Yoshie Motomura; Haruo Kitahara; Yumiko Yoshiki; Kazuyoshi Okubo

    1999-01-01

    Soy sauce was found to contain promoters of sediment formation at 60°C (1, 2), one of which has previously been identified as l-glutamic acid 5-n-butyl ester (3). Isomers and homologues of l-glutamic acid 5-n-butyl ester (n-propyl, isopropyl, n-butyl, isobutyl, and sec-butyl esters of l-glutamic acid) were synthesized using 80% (w\\/w) sulfuric acid as a catalyst and identified by 1H-NMR and

  6. Synthesis of medium chain length fatty acid ethyl esters in engineered Escherichia coli using endogenously produced medium chain fatty acids.

    PubMed

    Fan, Liping; Liu, Junfeng; Nie, Kaili; Liu, Luo; Wang, Fang; Tan, Tianwei; Deng, Li

    2013-07-10

    Microbial biosynthesis of fatty acid-derived biofuels from renewable carbon sources has attracted significant attention in recent years. Free fatty acids (FFAs) can be used as precursors for the production of micro-diesel. The expression of codon optimized two plants (Umbellularia californica and Cinnamomum camphora) medium-chain acyl-acyl carrier protein (ACP) thioesterase genes (ucFatB and ccFatB) in Escherichia coli resulted in a very high level of extractable medium-chain-specific hydrolytic activity and caused large accumulation of medium-chain free fatty acids. By heterologous co-expression of acyl-coenzyme A:diacylglycerol acyltransferase from Acinetobacter baylyi ADP1, specific plant thioesterases in E. coli, with supplementation of exogenous ethanol, resulted in drastic changes in fatty acid ethyl esters (FAEEs) composition ranging from 12:0 to 18:1. Through an optimized microbial shake-flask fermentation of two modified E. coli strains, yielded FFAs and FAEEs in the concentration of approximately 500 mg L(-1)/250 mg L(-1) and 2.01 mg g(-1)/1.99 mg g(-1), respectively. The optimal ethanol level for FAEEs yield in the two recombinant strains was reached at the 3% ethanol concentration, which was about 5.4-fold and 1.93-fold higher than that of 1% ethanol concentration. PMID:23769314

  7. Assessing human exposure to phthalic acid and phthalate esters from mineral water stored in polyethylene terephthalate and glass bottles

    Microsoft Academic Search

    P. Montuori; E. Jover; M. Morgantini; J. M. Bayona; M. Triassi

    2008-01-01

    Phthalic acid and phthalate esters are of growing interest due to their significant usage and potential toxicity. Polyethylene terephthalate (PET) and glass are both widely used materials for bottled drinking water. In this study, phthalic acid (PhA), bis(2-ethylhexyl) phthalate (DEHP), dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiisoBP) and dibutyl phthalate (DBP) were analysed in a large number of

  8. Metal Extraction by Silyl?Substituted Diphosphonic Acids. III. Ester Group Substituent Effects on Phosphoryl Oxygen Basicity

    Microsoft Academic Search

    P. R. Zalupski; D. R. McAlister; D. C. Stepinski; A. W. Herlinger

    2003-01-01

    Partial esters of alkylenediphosphonic acids are powerful metal ion extractants for actinides in all oxidation states. A study of americium extraction by silyl?substituted alkylenediphosphonic acids revealed higher extraction efficiency for these ligands compared to their 2?ethylhexyl analogs. The increased efficiency of silyl extractants could arise from differences in phosphoryl oxygen basicity and\\/or metal complex aqueous phase solubility. Substituent effects for

  9. Used frying oils and fats and their utilization in the production of methyl esters of higher fatty acids

    Microsoft Academic Search

    Ján Cvengroš; Zuzana Cvengrošová

    2004-01-01

    From the point of view price and available capacity used frying oils or fats (UFO) represent an attractive raw material for the production of methyl esters (ME) of higher fatty acids as alternative fuels for diesel engines. If they are treated such that the required quality, with an acidity number up to 3.0mgKOH\\/g and a water content up to 0.1wt%,

  10. On the Rate of Boronate Ester Formation in ortho-Aminomethyl Functionalized Phenyl Boronic Acids‡

    PubMed Central

    Collins, Byron E.; Metola, Pedro

    2012-01-01

    The role of the ortho-aminomethyl functional group in phenyl boronic acids for sugar complexation is a topic of debate. To decipher its effect on the kinetics of boronate ester formation, we first performed pseudo-first order kinetics analyses at five pH values up to 4 mM in fructose, revealing a first-order kinetic dependence upon fructose. Under these conditions, the reaction is in equilibrium and does not reach completion, but at 50 mM fructose saturation is achieved revealing zero-order dependence upon fructose. This indicates rate-determining creation of an intermediate prior to reaction with fructose, which we propose involves leaving group departure of inserted solvent. Further, the region of kinetics displaying zero-order dependence has a kinetic isotope effect (KIE) of 1.42, showing involvement of a proton transfer in the leaving group departure. The ratio of forward and reverse rate constants branching from the intermediate shows that fructose is several thousand times more nucleophilic than the solvent. Overall, the data supports a mechanism where the o-aminomethyl group lowers the pKa of the proximal boronic acid and acts as a general-acid (as an ammonium) to facilitate leaving group departure. Consequently, by microscopic reversibility the resulting amine must perform general-base catalysis to deliver fructose. PMID:23441105

  11. Chiral recognition of N-phthaloyl, N-tetrachlorophthaloyl, and N-naphthaloyl ?-amino acids and their esters on polysaccharide-derived chiral stationary phases.

    PubMed

    Kim, Byoung-Hyoun; Lee, Sang Uck; Moon, Dong Cheul

    2012-12-01

    Enantiomeric separations of N-phthaloyl (N-PHT), N-tetrachlorophthaloyl (N-TCPHT), and N-naphthaloyl (N-NPHT) ?-amino acids and their esters were examined on several kinds of polysaccharide-derived chiral stationary phases (CSPs). Resolution capability of CSPs was greater Chiralcel OF than the others for N-PHT and N-NPHT ?-amino acids and their esters. In N-TCPHT ?-amino acids and their esters, good enantioselectivities showed Chiralcel OG for N-TCPHT ?-amino acids, Chiralpak AD for N-TCPHT ?-amino acid methyl esters, and Chiralcel OD for N-TCPHT ?-amino acid ethyl esters, respectively. From the results of liquid chromatography and computational chemistry, it is concluded that l-form is preferred and more retained with electrostatic interaction in case of interaction between N-PHT ?-amino acid derivatives and Chiralcel OF, N-TCPHT ?-amino acid derivatives and Chiralcel OD, and N-NPHT ?-amino acid derivatives and Chiracel OF. On the other hand, d-form is preferred and more retained with van der Waals interaction in case of interaction between N-TCPHT ?-amino acid ester derivatives and Chiralcel OG and Chiralpak AD. PMID:22847739

  12. Role of HCA? (GPR109A) in nicotinic acid and fumaric acid ester-induced effects on the skin.

    PubMed

    Hanson, Julien; Gille, Andreas; Offermanns, Stefan

    2012-10-01

    Nicotinic acid (NA) and fumaric acid esters (FAE) such as monomethyl fumarate or dimethyl fumarate are drugs that elicit a cutaneous reaction called flushing as a side effect. NA is used to reduce progression of atherosclerosis through its anti-dyslipidemic activity and lipid-independent mechanisms involving immune cells, whereas FAE are used to treat psoriasis via largely unknown mechanisms. Both, NA and FAE, induce flushing by the activation of the G-protein-coupled receptor (GPCR) Hydroxy-carboxylic acid receptor 2 (HCA?, GPR109A) in cells of the epidermis. While the wanted effects of NA are at least in part also mediated by HCA?, it is currently not clear whether this receptor is also involved in the anti-psoriatic effects of FAE. The HCA?-mediated flushing response to these drugs involves the formation of prostaglandins D? and E? by Langerhans cells and keratinocytes via COX-1 in Langerhans cells and COX-2 in keratinocytes. This review summarizes recent progress in the understanding of the mechanisms underlying HCA?-mediated flushing, describes strategies to mitigate it and discusses the potential link between flushing, HCA? and the anti-psoriatic effects of FAE. PMID:22743741

  13. Fatty alcohols in capelin, herring and mackerel oils and muscle lipids: II. A comparison of fatty acids from wax esters with those of triglycerides

    Microsoft Academic Search

    W. N. Ratnayake; R. G. Ackman

    1979-01-01

    The fatty acids recovered from the triglycerides and wax esters of common northwest Atlantic copepods are compared with the\\u000a fatty acids of wax esters recovered intact from certain fish skin and body lipid, and from commercial fish oils. The fish\\u000a species, herring, capelin and mackerel, all feed on copepods, and many resemblances of the copepod lipid fatty acids to those

  14. Reaction of 2,5-bis(methoxycarbonyl)-3,4-diphenylcyclopentadienone with phosphonoacetic acid trimethyl ester

    SciTech Connect

    Fuzhenkova, A.V.; Galyautdinov, N.I.; Vagapova, N.N.

    1987-12-20

    It is known that the ease of the 1,5 migration of groups in cyclopentadienes is associated with their acceptor power. On the basis of this and in view of the tendency of phosphonoacetic acid triester to react at the C=O group of ..cap alpha..-enols (Wittig-Horner reaction), the authors studied the reactions of phosphonoacetic acid trimethyl ester with cyclones. 2,5-Bis(methoxycarbonyl)-3,4-diphenylcyclopentadienone reacts with the sodium derivative of phosphonoacetic acid trimethyl ester with the formation of adducts in which the carbanion center of the reagent is linked to the C/sup 2/ atom of cyclopentadienone. The IR spectra were determined on a UR-10 spectrometer. The PMR spectra were recorded on Varian T-60 and Tesla BS-467A spectrometer, solvent CHCl/sub 3/ or CDCl/sub 3/, internal standard TMS.

  15. In vitro digestion of citric acid esters of mono- and diglycerides (CITREM) and CITREM-containing infant formula/emulsions.

    PubMed

    Amara, Sawsan; Patin, Amaury; Giuffrida, Francesca; Wooster, Tim J; Thakkar, Sagar K; Bénarouche, Anaïs; Poncin, Isabelle; Robert, Sylvie; Point, Vanessa; Molinari, Sacha; Gaussier, Hélène; Diomande, Sadia; Destaillats, Frédéric; Cruz-Hernandez, Cristina; Carrière, Frédéric

    2014-07-25

    CITREM is an emulsifier used in the food industry and contains citric acid esters of mono- and diglycerides (GCFE). It is generally recognized as safe but no publication on its digestibility under gastrointestinal conditions and impact on fat digestion was available. It was shown here that fatty acids are released from CITREM by gastric lipase, pancreatic lipase, pancreatic-lipase-related protein 2 and carboxyl ester hydrolase. A two-step in vitro digestion model mimicking lipolysis in the stomach and upper small intestine of term and preterm infants was then used to evaluate the digestibility of CITREM alone, CITREM-containing infant formula and fat emulsions, and isolated GCFE fractions. Overall, it was shown that fat digestion is not significantly changed by the presence of CITREM, and fatty acids contained in CITREM compounds are released to a large extent by lipases. Nevertheless, undigestible water-soluble compounds containing glycerol and citric acid units were identified, indicating that the ester bond between citric acid and glycerol is not fully hydrolyzed throughout the proposed digestion. PMID:24777447

  16. Identification of 3-hydroxypalmitic acid methyl ester as a novel autoregulator controlling virulence in Ralstonia solanacearum.

    PubMed

    Flavier, A B; Clough, S J; Schell, M A; Denny, T P

    1997-10-01

    Expression of virulence genes in Ralstonia solanacearum, a phytopathogenic bacterium, is controlled by a complex regulatory network that integrates multiple signal inputs. Production of several virulence determinants is coordinately reduced by inactivation of phcB, but is restored by growth in the presence of a volatile extracellular factor (VEF) produced by wild-type strains of R. solanacearum. The VEF was purified from spent culture broth by distillation, solvent extraction, and liquid chromatography. Gas chromatography and mass spectroscopy identified 3-hydroxypalmitic acid methyl ester (3-OH PAME) as the major component in the single peak of VEF activity. Authentic 3-OH PAME and the purified VEF were active at < or =1 nM, and had nearly equivalent specific activities for stimulating the expression of eps (the biosynthetic locus for extracellular polysaccharide) in a phcB mutant. Authentic 3-OH PAME also increased the production of three virulence factors by a phcB mutant over 20-fold to wild-type levels, restored normal cell density-associated expression of eps and increased expression of eps when delivered via the vapour phase. Reanalysis of the PhcB amino acid sequence suggested that it is a small-molecule S-adenosylmethionine-dependent methyltransferase, which might catalyse synthesis of 3-OH PAME from a naturally occurring fatty acid. Biologically active concentrations of extracellular 3-OH PAME were detected before the onset of eps expression, suggesting that it is an intercellular signal that autoregulates virulence gene expression in wild-type R. solanacearum. Other than acyl-homoserine lactones, 3-OH PAME is the only endogenous fatty acid derivative shown to be an autoregulator and may be the first example of a new family of compounds that can mediate long-distance intercellular communication. PMID:9383151

  17. Effect of ionic liquids on enzymatic synthesis of caffeic acid phenethyl ester.

    PubMed

    Ha, Sung Ho; Anh, Tran Van; Lee, Sang Hyun; Koo, Yoon-Mo

    2012-01-01

    Although caffeic acid phenethyl ester (CAPE), an active flavonoid, plays an important role in the antioxidant activity of honeybee propolis, the isolation of CAPE from honeybee propolis is time-consuming due to wide variety of impurities present. Therefore, biochemical method to synthesize CAPE was investigated in this study. Since ionic liquids (ILs) possess some unique characteristics as appreciated alternatives to conventional solvents for certain biotransformation, the effect of ILs as reaction media for enzymatic synthesis of CAPE was assessed. Several factors including substrate molar ratio, and reaction temperature affecting the conversion yield of lipase-catalyzed CAPE synthesis were also investigated. Reaction yields were significantly higher in hydrophobic ILs than in hydrophilic ILs (almost zero). Among nine hydrophobic ILs tested, the highest conversion of synthetic reaction was obtained in 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Emim][Tf(2)N]). A reaction temperature of 70 °C was found to give high conversion. In addition, optimal substrate molar ratio between phenethyl alcohol and caffeic acid (CA) was decreased significantly from 92:1 to 30:1 when ILs were used instead of isooctane. PMID:21909673

  18. Genetic diversity of phthalic acid esters-degrading bacteria isolated from different geographical regions of China.

    PubMed

    Liang, Renxing; Wu, Xueling; Dai, Qinyun; Jin, Decai; Wang, Yangyang

    2010-01-01

    Thirty-two strains of phthalic acid ester (PAEs)-degrading bacteria were isolated from thirteen geographically diverse sites by enrichment using mixtures of PAEs as the sole source of carbon and energy. Sequence analyses of the 16S rRNA gene indicated that these isolates were from six genera (Arthrobacter, Gordonia, Rhodococcus, Acinetobacter, Pseudomonas, and Delftia). To evaluate the genetic diversity among them, the molecular typing method rep-PCR with primers based on enterobacterial repetitive intergenic consensus, repetitive extragenic palindromes, and BOXAIR sequences was performed. Strain-specific and unique genotypic fingerprints were distinguished for most of these isolates. In addition, utilization of various PAEs and the central intermediate phthalic acid by representative isolates suggested inter-isolate differences in the substrate utilization and degradation pathways. Furthermore, HPLC analysis showed that the rate of dimethyl phthalate degradation varied from 48.32 to 100% between strains. These results suggest a high level of genetic diversity among PAEs-degrading bacteria in the natural environment and their great potential to clean up phthalates-contaminated environments. PMID:19866373

  19. Novel quercetin-3-O-glucoside eicosapentaenoic acid ester ameliorates inflammation and hyperlipidemia.

    PubMed

    Sekhon-Loodu, Satvir; Ziaullah, Ziaullah; Rupasinghe, H P Vasantha; Wang, Yanwen; Kulka, Marianna; Shahidi, Fereidoon

    2015-08-01

    Quercetin, a major flavonol, present abundantly in apples and onions, is widely studied for ameliorating metabolic syndrome abnormalities. However, quercetin is mainly present in plant food in the form of quercetin glycosides and has been reported for poor gastrointestinal absorption. The present study was designed with the purpose of imparting a lipophilic property to quercetin-3-O-glucoside (QG) by its acylation with eicosapentaenoic acid (EPA) and to study the influence of eicosapentaenoic acid ester of quercetin-3-O-glucoside (QE) on hyperlipidemia and inflammation in vivo and in vitro. QE was more effective in reducing the production of tumor necrosis factor-alpha (TNF-?), prostaglandin 2 (PGE2), cyclo-oxygenase (COX)-2 levels and nuclear expression of nuclear factor-kappa B (NF-?B) compared to the parent compounds (QG and EPA) and commercial drugs, after lipopolysaccharides (LPS) induced inflammation in THP-1 derived macrophages. Serum high-density lipoprotein (HDL)-cholesterol was significantly higher and hepatic total cholesterol concentration was lower in the rats fed high-fat diet supplemented with QE, compared to the high-fat diet with inflammation (HFL). The serum concentrations of C-reactive protein (CRP), interleukin (IL)-6, and interferon-gamma (IFN-?) were significantly lower in QE treatment group than HFL group. EPA conjugated flavonol, QE, had significant anti-inflammatory and hypolipidemic properties and may be effective for the treatment of obesity-related disorders. PMID:26165697

  20. Regulatory effects of caffeic acid phenethyl ester on neuroinflammation in microglial cells.

    PubMed

    Tsai, Cheng-Fang; Kuo, Yueh-Hsiung; Yeh, Wei-Lan; Wu, Caren Yu-Ju; Lin, Hsiao-Yun; Lai, Sheng-Wei; Liu, Yu-Shu; Wu, Ling-Hsuan; Lu, Jheng-Kun; Lu, Dah-Yuu

    2015-01-01

    Microglial activation has been widely demonstrated to mediate inflammatory processes that are crucial in several neurodegenerative disorders. Pharmaceuticals that can deliver direct inhibitory effects on microglia are therefore considered as a potential strategy to counter balance neurodegenerative progression. Caffeic acid phenethyl ester (CAPE), a natural phenol in honeybee propolis, is known to possess antioxidant, anti-inflammatory and anti-microbial properties. Accordingly, the current study intended to probe the effects of CAPE on microglia activation by using in vitro and in vivo models. Western blot and Griess reaction assay revealed CAPE significantly inhibited the expressions of inducible nitric oxide synthase (NOS), cyclooxygenase (COX)-2 and the production of nitric oxide (NO). Administration of CAPE resulted in increased expressions of hemeoxygenase (HO)-1and erythropoietin (EPO) in microglia. The phosphorylated adenosine monophosphate-activated protein kinase (AMPK)-? was further found to regulate the anti-inflammatory effects of caffeic acid. In vivo results from immunohistochemistry along with rotarod test also revealed the anti-neuroinflammatory effects of CAPE in microglia activation. The current study has evidenced several possible molecular determinants, AMPK?, EPO, and HO-1, in mediating anti-neuroinflammatory responses in microglial cells. PMID:25768341

  1. Selective tert-butyl ester deprotection in the presence of acid labile protecting groups with use of ZnBr2.

    PubMed

    Kaul, Ramesh; Brouillette, Yann; Sajjadi, Zohreh; Hansford, Karl A; Lubell, William D

    2004-09-01

    Chemoselective hydrolysis of tert-butyl esters in the presence of other acid-labile groups has been explored by employing alpha-amino esters and ZnBr(2) in DCM. Although N-Boc and N-trityl groups were found to be labile, PhF protected amines were compatible with these Lewis acid deprotection conditions such that a variety of N-(PhF)amino acids were prepared in good yields from their corresponding tert-butyl esters. PMID:15373501

  2. Dimer acid esters by simultaneous dehydration and polymerization of technical methyl ricinoleate

    Microsoft Academic Search

    G. Silverstone

    1967-01-01

    Filtrol 13 may be used to dehydrate methyl ricinoleate with simultaneous dimerization and polymerization of the linoleate\\u000a esters formed. Hydrolysis of the ester group is avoided by the use of xylene as an azeotroping solvent and the preferred method\\u000a of reaction is the dropwise addition of the ester to a stirred suspension of catalyst in xylene. Products prepared by this

  3. Oxygen absorption of methyl esters of fat acids, and the effect of antioxidants

    Microsoft Academic Search

    A. J. Stirton; J. Turer; R. W. Riemenschneider

    1945-01-01

    Summary  The oxygen absorption of methyl linolenate, methyl linoleate, methyl oleate, methyl stearate, the distilled methyl esters\\u000a of lard, and various mixtures of the four individual methyl esters were measured at 100 C. in the Barcroft-Warburg apparatus.\\u000a Mixtures of methyl esters absorbed oxygen at a rate which could be approximately predicted from the rate of oxygen absorption\\u000a of each component and

  4. Synthesis and cytotoxic properties of derivatives of the tert -butyl ester of 7-alkylidene-3-methyl-3-cepheme-4-carboxylic acid

    Microsoft Academic Search

    M. Vorona; I. Potorocina; G. Veinberg; I. Shestakova; I. Kanepe; E. Lukevics

    2008-01-01

    Sulfones of the tert-butyl esters of 7-arylmethylene-and 7-(2-furyl)methylene-3-methyl-3-cepheme-4-carboxylic acid were obtained\\u000a by the condensation of the tert-butyl ester of 3-methyl-7-oxo-3-cepheme-4-carboxylic acid with arylmethylene-and 2-furylidenetriphenylphosphoranes\\u000a and subsequent oxidation of the intermediate products by meta-chloroperbenzoic acid. The combination of the tert-butyl esters\\u000a of 7E-bromomethylene-and 7,7-dibromomethylene-3-methyl-1,1-dioxo-3-cepheme-4-carboxylic acids with trimethylsilylacetylene\\u000a under conditions of the Sonogashira reaction gave the tert-butyl esters of 3-methyl-1,1-dioxo-7E-(3-trimethylsilyl-2-propynylidene)-3-cepheme-4-carboxylic\\u000a acid and

  5. Pseudo-poly(amino acid)s: study on construction and characterization of novel chiral and thermally stable nanostructured poly(ester-imide)s containing different trimellitylimido-amino acid-based diacids and pyromellitoyl-tyrosine-based diol

    Microsoft Academic Search

    Shadpour Mallakpour; Fatemeh Zeraatpisheh

    2011-01-01

    A new class of chiral and potentially biodegradable poly(ester-imide)s (PEI)s as pseudo-poly(amino acid)s (PAA)s bearing natural\\u000a amino acids in the main chain was synthesized. In this investigation, N,N?-(pyromellitoyl)-bis-(L-tyrosine dimethyl ester) as a biodegradable optically active diphenol and synthesized trimellitic\\u000a anhydride-derived dicarboxylic acids containing different natural amino acids such as S-valine, L-methionine, L-leucine, L-isoleucine,\\u000a and L-phenylalanine were used for direct polyesterification.

  6. Sorption of silicic acid from non-saturated aqueous solution by a complex of zinc ions with poly(vinylamine)

    Microsoft Academic Search

    Elena Danilovtseva; Vladimir Aseyev; Mikko Karesoja; Vadim Annenkov

    2009-01-01

    Silicifying organisms (diatom algae, sponges, etc.) build multifarious silica and composite nano-structures which attracts rapt attention of specialists in nanotechnology. These organisms can capture monomeric silicic acid from diluted solutions (<1mM) and molecular mechanism of this process is still unknown. Some hypotheses include mediatorial role of zinc ions coordinated with a special protein transporter. We have studied several basic hydrogels

  7. Electronic spectroscopy of tryptophan analogs in supersonic jets: 3Indole acetic acid, 3-indole propionic acid, tryptamine, and N-acetyl tryptophan ethyl ester

    Microsoft Academic Search

    Young D. Park; Thomas R. Rizzo; Linda A. Peteanu; Donald H. Levy

    1986-01-01

    The electronic spectroscopy of four different tryptophan analogs, 3-indole acetic acid, 3-indole propionic acid, tryptamine, and N-acetyltryptophan ethyl ester (NATE) has been studied in a supersonic molecular beam using laser-induced fluorescence and resonantly enhanced two-photon ionization. The electronic transition to the lowest excited singlet state occurs at 35 039, 34 965, 34 918, and 34 881±2 cm?1 for 3-indole acetic

  8. Application of urea complexes in the purification of fatty acids, esters, and alcohols. II. Oleic acid and methyl oleate from olive oil

    Microsoft Academic Search

    Daniel Swern; Winfred E. Parker

    1952-01-01

    Summary  Oleic acid and methyl oleate of high purity (97–99%) and substantially free (0.2% or less) of polyunsaturated contaminants\\u000a have been isolated in 60–70% yield from the fatty acids or methyl esters of olive oil by procedures which require only one\\u000a precipitation of urea complexes (single dose of urea technique) one low-temperature crystallization, and one fractional distillation.\\u000a The best yields of

  9. Rice hull ash and silicic acid as adsorbents for concentration of bacteriocins

    PubMed

    Janes; Nannapaneni; Proctor; Johnson

    1998-11-01

    A model procedure has been developed for the rapid extraction of five bacteriocins (nisin, pediocin RS2, leucocin BC2, lactocin GI3, and enterocin CS1) from concentrated freeze-dried crude culture supernatants by adsorption onto acid or alkaline rice hull ash (RHA) or silicic acid (SA). Bacteriocins were adsorbed onto RHA or SA by a pH-dependent method and desorbed by decreasing the pH to 2.5 or 3.0 and heating at 90 degreesC for 5 min. The maximum adsorption and optimal pH range for different bacteriocins were as follows: nisin, 97% at pH 7.0; lactocin GI3, 94% at pH 6.0; pediocin RS2, 97% at pH 8.0 to 9.0; leucocin BC2, 88% at pH 9.0; and enterocin CS1, 94% at pH 5.0. The desorption level of lactocin GI3 or enterocin CS1 from the surfaces of both RHA and SA was 94%, while the desorption level of pediocin RS2 and leucocin BC2 was 50% or less. Nisin was desorbed readily from SA (91%) but not from RHA (50% or less). The adsorption of bacteriocins onto RHA and SA increased with the increasing concentration of bacteriocins. Analysis of the desorbed bacteriocins after dialysis and sodium dodecyl sulfate-16% polyacrylamide gel electrophoresis showed a single band that gave a single inhibition zone when overlaid with Lactobacillus plantarum for detection of lactocin GI3, enterocin CS1, and nisin. RHA appears useful for extraction, concentration, and partial purification of the five bacteriocins. PMID:9797298

  10. Rice Hull Ash and Silicic Acid as Adsorbents for Concentration of Bacteriocins†

    PubMed Central

    Janes, M. E.; Nannapaneni, R.; Proctor, A.; Johnson, M. G.

    1998-01-01

    A model procedure has been developed for the rapid extraction of five bacteriocins (nisin, pediocin RS2, leucocin BC2, lactocin GI3, and enterocin CS1) from concentrated freeze-dried crude culture supernatants by adsorption onto acid or alkaline rice hull ash (RHA) or silicic acid (SA). Bacteriocins were adsorbed onto RHA or SA by a pH-dependent method and desorbed by decreasing the pH to 2.5 or 3.0 and heating at 90°C for 5 min. The maximum adsorption and optimal pH range for different bacteriocins were as follows: nisin, 97% at pH 7.0; lactocin GI3, 94% at pH 6.0; pediocin RS2, 97% at pH 8.0 to 9.0; leucocin BC2, 88% at pH 9.0; and enterocin CS1, 94% at pH 5.0. The desorption level of lactocin GI3 or enterocin CS1 from the surfaces of both RHA and SA was 94%, while the desorption level of pediocin RS2 and leucocin BC2 was 50% or less. Nisin was desorbed readily from SA (91%) but not from RHA (50% or less). The adsorption of bacteriocins onto RHA and SA increased with the increasing concentration of bacteriocins. Analysis of the desorbed bacteriocins after dialysis and sodium dodecyl sulfate–16% polyacrylamide gel electrophoresis showed a single band that gave a single inhibition zone when overlaid with Lactobacillus plantarum for detection of lactocin GI3, enterocin CS1, and nisin. RHA appears useful for extraction, concentration, and partial purification of the five bacteriocins. PMID:9797298

  11. Compositional effects on Si–OH bond length in hydrous silicates with implications for trends in the SiOH acidity

    SciTech Connect

    Zarubin, Dmitri P., E-mail: dmitri.zarubin@mtu-net.ru

    2014-04-01

    Theoretical calculations of the structure and Brønsted acidity of SiOH groups in silica clusters have never addressed the question if these vary with the degree of SiOH deprotonation. In this connection, a statistical analysis is presented of Si–OH bond lengths in crystalline hydrogen silicates with well-determined structures with a special emphasis placed on effects of the silicate composition. It is found that among hydrogen silicates of large cations with low charges the Si–OH bonds are always longer than terminal Si–O bonds in the same anion and correlate in length with the anionic charge per tetrahedron. The findings are explained by steric limitations on charge balancing at oxygen atoms by hydrogen bonds and/or cations. It is suggested that similar limitations and imbalances may underlie the well-known trends in the Brønsted acidity of silicic acids and silicas in aqueous media: decreased acidity with increased SiOH deprotonation and increased acidity with increased tetrahedra connectivity. - Graphical abstract: Si–OH bonds in crystalline silicates lengthen with the anionic charge per tetrahedron, which is in parallel with the well-known trend of decreased acidity of silicic acids and silicas in solution with increased degree of deprotonation. - Highlights: • Si–OH bonds in alkali hydrogen silicates are always longer than terminal Si–O bonds. • Si–OH bonds in silicates lengthen with the anionic charge per tetrahedron. • The Si–OH bond elongation results from inherent underbonding of terminal O atoms. • The longer the Si–OH bond, the less acidic the OH group is.

  12. Diatom productivity in the equatorial Pacific Ocean from the last glacial period to the present: A test of the silicic acid leakage hypothesis

    Microsoft Academic Search

    L. I. Bradtmiller; R. F. Anderson; M. Q. Fleisher; L. H. Burckle

    2006-01-01

    The silicic acid leakage hypothesis (SALH) suggests that during glacial periods, unused silicic acid escaped the Southern Ocean into the equatorial oceans, causing an ecological shift favoring diatoms relative to coccolithophorids and a drawdown of CO2. The 230Th normalized opal fluxes and 231Pa\\/230Th ratios were measured in eleven equatorial Pacific cores to reconstruct diatom productivity over the past 30 kyr

  13. Synthesis and Antioxidant Evaluation of Enantiomerically Pure Bis-(1,2,3-triazolylmethyl)amino Esters from Modified ?-Amino Acids

    PubMed Central

    Sarmiento-Sánchez, Juan I.; Ochoa-Terán, Adrián; Rivero, Ignacio A.

    2014-01-01

    The efforts for synthesis of enantiomerically pure bis-(1,2,3-triazolylmethyl)amino esters 6 are reported in good yields from an in situ generated ?-azidomethyl ketone. Optimum experimental conditions were established for preparation of ?-halomethyl ketones 10 and ?-N,N-dipropargylamino esters 11, all derived from ?-amino acids. The starting materials reacted under conventional click chemistry conditions, revealing a specific reactivity of bromomethyl ketones over chloromethyl ketones. The antioxidant activity of compounds 6 was assayed by DPPH method. The compound 6c with an IC50 of 75.57 ± 1.74??g?mL?1 was the most active. Technically, this methodology allows the preparation of a combinatorial library of analogues with different structural characteristics depending on the nature of the modified ?-amino acids employed in the synthesis. PMID:25386592

  14. Inhibition of TVimor Promoter-mediated Processes in Mouse Skin and Bovine Lens by Caffeic Acid Phenethyl Ester1

    Microsoft Academic Search

    Krystyna Frenkel; Huachen Wei; Ramesh Bhimani; Jose A. Zadunaisky; Thomas Ferrare; Allan H. Conney; Dezider Grunberger

    1993-01-01

    Caffeic acid phenethyl ester (CAPE) was isolated from propolis (a product of honeybee hives) that has been used in folk medicine as a potent antiinflammatory agent. CAPE is cytotoxic to tumor and virally trans formed but not to normal cells. Our main goal was to establish whether CAPE inhibits the tumor promoter (12-0-tetradecanoylphorbol-13-ace- tate)-induced processes associated with carcinogenesis. Topical treatment

  15. Ameliorating role of caffeic acid phenethyl ester (CAPE) against isoniazid-induced oxidative damage in red blood cells

    Microsoft Academic Search

    Osman Gokalp; Efkan Uz; Ekrem Cicek; H. Ramazan Yilmaz; Mehmet Kaya Ozer; Ayse Altunbasak; Nurten Ozcelik

    2006-01-01

    Isoniazid (INH) still remains a first-line drug both for treatment and prophylaxis of tuberculosis, but various organs toxicity\\u000a frequently develops in patients receiving this drug. We aimed to investigate possible toxic effects of INH on rat red blood\\u000a cells (RBCs), and to elucidate whether Caffeic acid phenethyl ester (CAPE) prevents a possible toxic effect of INH. Experimental\\u000a groups were designed

  16. Enzymatic transesterification of fats and oils from animal discards to fatty acid ethyl esters for potential fuel use

    Microsoft Academic Search

    Alberta N. A. Aryee; Benjamin K. Simpson; Roger I. Cue; Leroy E. Phillip

    2011-01-01

    Fatty acid ethyl ester (FAEE) for use as biodiesel (BD) was produced by enzymatic transesterification of salmon skin oil (SSO), a commercial oil-fat blend of yellow grease and rendered animal fat (referred to as Rothsay composite, RC), and olive oil (OO) with Lipozyme-IM® as catalyst. The effects of temperature (25–65 °C), oil: alcohol molar ratio (1:1–1:6), alcohol type (ethanol or methanol),

  17. Synthesis and lithographic evaluation of poly[(methacrylic acid tert-butyl cholate ester)- co-(?-butyrolactone-2-yl methacrylate)

    Microsoft Academic Search

    Jin-Baek Kim; Jong-Sung Ko; Jae-Hak Choi; Ji-Hyun Jang; Tae-Hwan Oh; Hyun-woo Kim; Bum-wook Lee

    2004-01-01

    Poly[(methacrylic acid tert-butyl cholate ester)-co-(?-butyrolactone-2-yl methacrylate)] was synthesized and evaluated as a new 193-nm chemically amplified photoresist. This polymer showed good thermal stability up to 240 °C and had a good transmittance at 193 nm. This material showed good resistance to CF4-reactive ion etching. The resist patterns of 0.15 ?m feature size were obtained at a dose of 11mJcm?2 using

  18. Protective effect of caffeic acid phenethyl ester on tert-butyl hydroperoxide-induced oxidative hepatotoxicity and DNA damage

    Microsoft Academic Search

    Kyung Jin Lee; Jae Ho Choi; Yong Pil Hwang; Young Chul Chung; Hye Gwang Jeong

    2008-01-01

    Increased oxidative stress and associated high levels of free radical generation have been described to occur during the pathogeneses of various diseases in animal models. In the present work, we investigated the protective effects of the phenethyl ester of caffeic acid (CAPE), an active component of honeybee propolis, on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in a cultured HepG2 cell line and

  19. Binary diffusion coefficients and retention factors for ?-linolenic acid and its methyl and ethyl esters in supercritical carbon dioxide

    Microsoft Academic Search

    Chang Yi Kong; Nirosha R. W. Withanage; Toshitaka Funazukuri; Seiichiro Kagei

    2006-01-01

    Infinite dilution binary diffusion coefficients D12 and retention factors k for ?-linolenic acid were measured by chromatographic impulse response technique in supercritical carbon dioxide over the ranges of temperature from 308 to 343K and pressure from 9 to 30MPa, together with those for the methyl and ethyl esters at 313 and 343K and pressures from 8 to 16MPa. In comparison

  20. Rigid urethane foams from hydroxymethylated castor oil, safflower oil, oleic safflower oil, and polyol esters of castor acids

    Microsoft Academic Search

    C. K. Lyon; V. H. Garrett; E. N. Frankel

    1974-01-01

    Castor, safflower, and oleic safflower oil derivatives with enhanced reactivity and hydroxyl group content were prepared by\\u000a hydroformylation with a rhodium-triphenylphosphine catalyst, followed by hydrogenation. Rigid urethane foams prepared from\\u000a these hydroxymethylated derivatives had excellent compressive strengths, closed cell contents, and dimensional stability.\\u000a Best properties were obtained from hydroxymethylated polyol esters of castor acids.

  1. Value of Caffeic Acid Phenethyl Ester Pretreatment in Experimental Sepsis Model in Rats

    PubMed Central

    Alici, Ozlem; Kavakli, Havva Sahin; Koca, Cemile; Altintas, Neriman Defne; Aydin, Murat; Alici, Suleyman

    2015-01-01

    Background and Aim. The aim of this study was to determine the actions of caffeic acid phenethyl ester (CAPE) on the changes of endothelin-1 (ET-1) level, tumor necrosis factor- (TNF-) alpha, and oxidative stress parameters such as superoxide dismutase (SOD) activities and malondialdehyde (MDA) levels in experimental sepsis model in rats. Materials and Methods. Twenty-four rats were randomly divided into three experimental groups: sham (group 1), sepsis (group 2), and sepsis + CAPE (group 3), n = 8 each. CAPE was administered (10?µmol/kg) intraperitoneally to group 3 before sepsis induction. Serum ET-1, serum TNF-alpha, tissue SOD activity, and tissue MDA levels were measured in all groups. Results. Pretreatment with CAPE decreased ET-1, TNF-alpha, and MDA levels in sepsis induced rats. Additionally SOD activities were higher in rats pretreated with CAPE after sepsis induction. Conclusion. Our results demonstrate that CAPE may have a beneficial effect on ET and TNF-alpha levels and oxidative stress parameters induced by sepsis in experimental rat models. Therefore treatment with CAPE can be used to avoid devastating effects of sepsis. PMID:25948886

  2. Therapeutic effect of caffeic acid phenethyl ester on cerulein-induced acute pancreatitis

    PubMed Central

    Buyukberber, Mehmet; Sava?, M Cemil; Bagci, Cahit; Koruk, Mehmet; Gulsen, Murat T; Tutar, Ediz; Bilgic, Tugba; Ceylan, Nurdan Ö

    2009-01-01

    AIM: To evaluate the therapeutic role of caffeic acid phenethyl ester (CAPE) in a rat model of cerulean-induced acute pancreatitis (AP). METHODS: Seventy male Wistar albino rats were divided into seven groups. Acute edematous pancreatitis was induced by subcutaneous cerulein injection (20 ?g/kg) four times at 1-h intervals. CAPE (30 mg/kg) was given by subcutaneous injection at the beginning (CAPE 1 group) and 12 h after the last cerulein injection (CAPE 2 group). Serum amylase, lipase, white blood cell count, and tumor necrosis factor (TNF)-? levels were measured, and pancreatic histopathology was assessed. RESULTS: In the AP group, amylase and lipase levels were found to be elevated and the histopathological evaluation showed massive edema and inflammation of the pancreas, with less fatty necrosis when compared with sham and control groups. Amylase and lipase levels and edema formation decreased significantly in the CAPE therapy groups (P < 0001); especially in the CAPE 2 group, edema was improved nearly completely (P = 0001). Inflammation and fatty necrosis were partially recovered by CAPE treatment. The pathological results and amylase level in the placebo groups were similar to those in the AP group. White blood cell count and TNF-? concentration was nearly the same in the CAPE and placebo groups. CONCLUSION: CAPE may be useful agent in treatment of AP but more experimental and clinical studies are needed to support our observation of beneficial effects of CAPE before clinical usage of this agent. PMID:19891017

  3. Caffeic Acid Phenethyl Ester Is a Potential Therapeutic Agent for Oral Cancer

    PubMed Central

    Kuo, Ying-Yu; Jim, Wai-Tim; Su, Liang-Cheng; Chung, Chi-Jung; Lin, Ching-Yu; Huo, Chieh; Tseng, Jen-Chih; Huang, Shih-Han; Lai, Chih-Jen; Chen, Bo-Chih; Wang, Bi-Juan; Chan, Tzu-Min; Lin, Hui-Ping; Chang, Wun-Shaing Wayne; Chang, Chuang-Rung; Chuu, Chih-Pin

    2015-01-01

    Head and neck cancers, which affect 650,000 people and cause 350,000 deaths per year, is the sixth leading cancer by cancer incidence and eighth by cancer-related death worldwide. Oral cancer is the most common type of head and neck cancer. More than 90% of oral cancers are oral and oropharyngeal squamous cell carcinoma (OSCC). The overall five-year survival rate of OSCC patients is approximately 63%, which is due to the low response rate to current therapeutic drugs. In this review we discuss the possibility of using caffeic acid phenethyl ester (CAPE) as an alternative treatment for oral cancer. CAPE is a strong antioxidant extracted from honeybee hive propolis. Recent studies indicate that CAPE treatment can effectively suppress the proliferation, survival, and metastasis of oral cancer cells. CAPE treatment inhibits Akt signaling, cell cycle regulatory proteins, NF-?B function, as well as activity of matrix metalloproteinase (MMPs), epidermal growth factor receptor (EGFR), and Cyclooxygenase-2 (COX-2). Therefore, CAPE treatment induces cell cycle arrest and apoptosis in oral cancer cells. According to the evidence that aberrations in the EGFR/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling, NF-?B function, COX-2 activity, and MMPs activity are frequently found in oral cancers, and that the phosphorylation of Akt, EGFR, and COX-2 correlates to oral cancer patient survival and clinical progression, we believe that CAPE treatment will be useful for treatment of advanced oral cancer patients. PMID:25984601

  4. Identification of native catechin fatty acid esters in green tea (Camellia sinensis).

    PubMed

    Myers, Richard A; Fuller, Ewa; Yang, Weichun

    2013-11-27

    Catechins are potent antioxidants and make up the primary class of polyphenols present in tea (Camellia sinensis). They are especially abundant in the less-fermented green teas that have been employed in various foods to enhance shelf life stability (Senanayake, N. J. Funct. Foods 2013, in press. Gramza, A.; Korczak, J. Trends Food Sci. 2005, 16, 351-358). The antioxidative activity of native (polar) catechins has proven to be useful in foods of relatively high polarity, while mixed results have been achieved in high-fat foods. However, the polarity of catechins can be attenuated by esterification with fatty acids, producing adducts that effectively partition into lipids and protect against rancidity even in high-fat foods (Cutler, S.; Fuller, E.; Rotberg, I.; Wray, C.; Troung, M.; Poss, M. International Patent WO 2013/036934 A1, March 14, 2013. Zhong, Y.; Shahidi, F. J. Agric. Food Chem. 2011, 59, 6526-6533). In this work, a search for the presence of naturally occurring lipid-conjugated catechins was undertaken in various green tea varieties. Rather than the traditional aqueous infusion, dried tea leaves were extracted with organic solvents followed by analysis for catechin adducts with both lower polarities and increased molecular weights as monitored by liquid chromatography and tandem mass spectrometry. Native catechin palmitates were identified and indirectly confirmed by synthesis and nuclear magnetic resonance as natural components of several Chinese green teas. Evidence of other fatty catechin esters was also observed. PMID:24251649

  5. Enzymatic synthesis of fatty acid ethyl esters by utilizing camellia oil soapstocks and diethyl carbonate.

    PubMed

    Wang, Yingying; Cao, Xuejun

    2011-11-01

    This study was reported on a novel process for fatty acid ethyl esters preparation by transesterification and esterification from renewable low-cost feedstock camellia oil soapstocks and friendly acyl acceptor diethyl carbonate. The main components of product were 83.9% ethyl oleate, 8.9% ethyl palmitate, 4.7% ethyl linoleate and 2.1% ethyl stearate, which could be used as eco-friendly renewable resources or additives of industrial solvent and fossil fuel. The effects of molar ratio of diethyl carbonate to soapstocks oil, lipases, organic solvent, reaction temperature and time were investigated, and process conditions were optimized. The yield was up to 98.4% in solvent-free system with molar ratio of diethyl carbonate to soapstocks oil 3:1 and 5% Novozym 435 (based on the weight of soapstocks oil) at 50 °C and 180 rpm for 24 h. Moreover, there was no obvious loss in the yield after lipases were reused for 10 batches without treatment under optimized conditions. PMID:21958524

  6. Enhancing fatty acid ethyl ester production in Saccharomyces cerevisiae through metabolic engineering and medium optimization.

    PubMed

    Thompson, R Adam; Trinh, Cong T

    2014-11-01

    Biodiesels in the form of fatty acyl ethyl esters (FAEEs) are a promising next generation biofuel due to their chemical properties and compatibility with existing infrastructure. It has recently been shown that expression of a bacterial acyl-transferase in the established industrial workhorse Saccharomyces cerevisiae can lead to production of FAEEs by condensation of fatty acyl-CoAs and ethanol. In contrast to recent strategies to produce FAEEs in S. cerevisiae through manipulation of de novo fatty acid biosynthesis or a series of arduous genetic manipulations, we introduced a novel genetic background, which is comparable in titer to previous reports with a fraction of the genetic disruption by aiming at increasing the fatty acyl-CoA pools. In addition, we combined metabolic engineering with modification of culture conditions to produce a maximum titer of over 25?mg/L FAEEs, a 40% improvement over previous reports and a 17-fold improvement over our initial characterizations. Biotechnol. Bioeng. 2014;111: 2200-2208. © 2014 Wiley Periodicals, Inc. PMID:24895195

  7. Electron Affinity of Phenyl-C61-Butyric Acid Methyl Ester (PCBM)

    SciTech Connect

    Larson, Bryon W.; Whitaker, James B.; Wang, Xue B.; Popov, Alexey A.; Rumbles, Garry; Kopidakis, Nikos; Strauss, Steven H.; Boltalina, Olga V.

    2013-07-25

    The gas-phase electron affinity (EA) of phenyl-C61-butyric acid methyl ester (PCBM), one of the best-performing electron acceptors in organic photovoltaic devices, is measured by lowtemperature photoelectron spectroscopy for the first time. The obtained value of 2.63(1) eV is only ca. 0.05 eV lower than that of C60 (2.68(1) eV), compared to a 0.09 V difference in their E1/2 values measured in this work by cyclic voltammetry. Literature E(LUMO) values for PCBM that are typically estimated from cyclic voltammetry, and commonly used as a quantitative measure of acceptor properties, are dispersed over a wide range between -4.3 and -3.62 eV; the reasons for such a huge discrepancy are analyzed here, and the protocol for reliable and consistent estimations of relative fullerene-based acceptor strength in solution is proposed.

  8. Negative polarity of phenyl-C61 butyric acid methyl ester adjacent to donor macromolecule domains

    NASA Astrophysics Data System (ADS)

    Alley, Olivia J.; Wu, Meng-Yin; Johns, Gary L.; Dawidczyk, Thomas J.; Hardigree, Josué F. Martínez; Markovic, Nina; Arnold, Michael S.; Katz, Howard E.

    2015-01-01

    Interfacial fields within organic photovoltaics influence the movement of free charge carriers, including exciton dissociation and recombination. Open circuit voltage (Voc) can also be dependent on the interfacial fields, in the event that they modulate the energy gap between donor HOMO and acceptor LUMO. A rise in the vacuum level of the acceptor will increase the gap and the Voc, which can be beneficial for device efficiency. Here, we measure the interfacial potential differences at donor-acceptor junctions using Scanning Kelvin Probe Microscopy, and quantify how much of the potential difference originates from physical contact between the donor and acceptor. We see a statistically significant and pervasive negative polarity on the phenyl-C61 butyric acid methyl ester (PCBM) side of PCBM/donor junctions, which should also be present at the complex interfaces in bulk heterojunctions. This potential difference may originate from molecular dipoles, interfacial interactions with donor materials, and/or equilibrium charge transfer due to the higher work function and electron affinity of PCBM. We show that the contact between PCBM and poly(3-hexylthiophene) doubles the interfacial potential difference, a statistically significant difference. Control experiments determined that this potential difference was not due to charges trapped in the underlying substrate. The direction of the observed potential difference would lead to increased Voc, but would also pose a barrier to electrons being injected into the PCBM and make recombination more favorable. Our method may allow unique information to be obtained in new donor-acceptor junctions.

  9. Phthalate acid esters in Potamogeton crispus L. from Haihe River, China.

    PubMed

    Chi, Jie

    2009-09-01

    This study was conducted in Haihe River, China, in order to assess the ability of Potamogeton crispus L. (P. crispus), a submerged plant, to accumulate phthalic acid esters (PAEs). Dibutyl phthalate (DBP) and di-2-ethylexyl phthalate (DEHP) were measured in samples of water, sediment and P. crispus plant from March to May 2008. The results showed that the highest levels of DBP and DEHP in above-ground tissues appeared during the blooming period of P. crispus, which was consistent with the results obtained with the water samples. Regression analysis reveals that concentrations of PAEs in above-ground tissues were mainly influenced by PAE concentrations in the water of Haihe River. Enrichment of DBP and DEHP in above-ground tissues was observed, with bioconcentration factors (BCFs) of 4.82-83.65Lkg(-1) for DBP and 6.71-93.70Lkg(-1) for DEHP. The distribution pattern of DBP in roots, surface and near root sediments was different from that of DEHP. Concentrations of DBP in near root sediments were lower than those in roots and comparable to those in surface sediments, while concentrations of DEHP in roots were lower than those in near root sediments but higher than those in surface sediments. PMID:19545887

  10. S-(-)-10,11-dihydroxyfarnesoic acid methyl ester inhibits melanin synthesis in murine melanocyte cells.

    PubMed

    Baek, Seung-Hwa; Ahn, Jun-Won; Nam, Sung-Hee; Yoon, Cheol-Sik; Shin, Jae-Cheon; Lee, Sang-Han

    2014-01-01

    The development of antimelanogenic agents is important for the prevention of serious aesthetic problems such as melasmas, freckles, age spots, and chloasmas. In the course of screening for melanin synthesis inhibitors, we found that the culture broth from an insect morphopathogenic fungus, Beauveria bassiana CS1029, exhibits potent antimelanogenic activity. We isolated and purified an active metabolite and identified it as S-(-)-10,11-dihydroxyfarnesoic acid methyl ester (dhFAME), an insect juvenile hormone. To address whether dhFAME inhibits melanin synthesis, we first measured the size of the melanin biosynthesis inhibition zone caused by dhFAME. dhFAME also showed inhibitory activity against mushroom tyrosinase in Melan-a cells. Intracellular, dose-dependent tyrosinase inhibition activity was also confirmed by zymography. In addition, we showed that dhFAME strongly inhibits melanin synthesis in Melan-a cells. Furthermore, we compared levels of TYR, TRP-1, TRP-2, MITF, and MC1R mRNA expression by reverse-transcription polymerase chain reaction and showed that treatment of Melan-a cells with 35 ?M dhFAME led to an 11-fold decrease in TYR expression, a 6-fold decrease in TRP-2 expression, and a 5-fold decrease in MITF expression. Together, these results indicate that dhFAME is a potent inhibitor of melanin synthesis that can potentially be used for cosmetic biomaterial(s). PMID:25046747

  11. Effects of ketamine and 1-glutamic acid diethyl ester on concept learning in rats.

    PubMed

    Lalonde, R; Joyal, C C

    1991-08-01

    The effects of ketamine, an NMDA receptor antagonist, and 1-glutamic acid diethyl ester (LGDE), a non-NMDA glutamate antagonist, were evaluated in the acquisition of concept learning in a water maze. In concept learning, the rats must locate an invisible platform whose location changes from day to day. In spatial learning (Morris task), the rats must locate an invisible (or visible) platform whose location does not change. Ketamine increased quadrant entries at 5, 10 and 20 mg/kg, and latencies at 10 and 20 mg/kg on the final two days of training on the concept task. At 5 mg/kg ketamine disrupted concept learning but not spatial learning or visuo-motor coordination as assessed by invisible and visible platform conditions of the Morris maze. Progressively higher doses of ketamine affected first the invisible condition and then the visible platform condition. On the other hand, LGDE did not affect the Morris task at any dose. However, there was no decrease in latencies over days in concept learning at the two highest doses (240 and 360 mg/kg) of LGDE. Thus LGDE appeared to slow down decision time in the concept task but not the spatial task in the absence of an effect on quadrant entries in any version. These results indicate that NMDA receptors are involved in spatial and concept learning. Non-NMDA receptors appear to be involved only in concept learning. PMID:1763100

  12. Caffeic Acid phenethyl ester is a potential therapeutic agent for oral cancer.

    PubMed

    Kuo, Ying-Yu; Jim, Wai-Tim; Su, Liang-Cheng; Chung, Chi-Jung; Lin, Ching-Yu; Huo, Chieh; Tseng, Jen-Chih; Huang, Shih-Han; Lai, Chih-Jen; Chen, Bo-Chih; Wang, Bi-Juan; Chan, Tzu-Min; Lin, Hui-Ping; Chang, Wun-Shaing Wayne; Chang, Chuang-Rung; Chuu, Chih-Pin

    2015-01-01

    Head and neck cancers, which affect 650,000 people and cause 350,000 deaths per year, is the sixth leading cancer by cancer incidence and eighth by cancer-related death worldwide. Oral cancer is the most common type of head and neck cancer. More than 90% of oral cancers are oral and oropharyngeal squamous cell carcinoma (OSCC). The overall five-year survival rate of OSCC patients is approximately 63%, which is due to the low response rate to current therapeutic drugs. In this review we discuss the possibility of using caffeic acid phenethyl ester (CAPE) as an alternative treatment for oral cancer. CAPE is a strong antioxidant extracted from honeybee hive propolis. Recent studies indicate that CAPE treatment can effectively suppress the proliferation, survival, and metastasis of oral cancer cells. CAPE treatment inhibits Akt signaling, cell cycle regulatory proteins, NF-?B function, as well as activity of matrix metalloproteinase (MMPs), epidermal growth factor receptor (EGFR), and Cyclooxygenase-2 (COX-2). Therefore, CAPE treatment induces cell cycle arrest and apoptosis in oral cancer cells. According to the evidence that aberrations in the EGFR/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling, NF-?B function, COX-2 activity, and MMPs activity are frequently found in oral cancers, and that the phosphorylation of Akt, EGFR, and COX-2 correlates to oral cancer patient survival and clinical progression, we believe that CAPE treatment will be useful for treatment of advanced oral cancer patients. PMID:25984601

  13. Kinetics of enzymatic synthesis of liquid wax ester from oleic acid and oleyl alcohol.

    PubMed

    Radzi, Salina Mat; Mohamad, Rosfarizan; Basri, Mahiran; Salleh, Abu Bakar; Ariff, Arbakariya; Rahman, Mohammad Basyaruddin Abdul; Rahman, Raja Noor Zaliha Raja Abdul

    2010-01-01

    The kinetics of wax ester synthesis from oleic acid and oleyl alcohol using immobilized lipase from Candida antartica as catalyst was studied with different types of impeller (Rushton turbine and AL-hydrofoil) to create different mixing conditions in 2l stirred tank reactor. The effects of catalyst concentration, reaction temperature, and impeller tip speed on the synthesis were also evaluated. Rushton turbine impeller exhibited highest conversion rate at lower impeller tip speed as compared to AL-hydrofoil impeller. A second-order reversible kinetic model from single progress curve for the prediction of fractional conversion at given reaction time was proposed and the corresponding kinetic parameter values were calculated by non-linear regression method. The results from the simulation using the proposed model showed satisfactory agreement with the experimental data. Activation energy shows a value of 21.77 Kcal/mol. The thermodynamic parameters of the process, enthalpy and entropy, were 21.15 Kcal/mol and 52.07 cal/mol.K, respectively. PMID:20124754

  14. Protective effects of caffeic acid phenethyl ester against acute radiation-induced hepatic injury in rats.

    PubMed

    Chu, JianJun; Zhang, Xiaojun; Jin, Liugen; Chen, Junliang; Du, Bin; Pang, Qingfeng

    2015-03-01

    Caffeic acid phenyl ester (CAPE) is a potent anti-inflammatory agent and it can eliminate the free radicals. The current study was intended to evaluate the protective effect of CAPE against the acute radiation-induced liver damage in rats. Male Sprague-Dawley rats were intraperitoneally administered with CAPE (30 mg/kg) for 3 consecutive days before exposing them to a single dose of 30 Gy of ?-ray irradiation to upper abdomen. We found that pretreatment with CAPE significantly decreased the serum levels of alanine aminotransferase and aspartate aminotransferase and increased the activity of superoxide dismutase and glutathione. Histological evaluation further confirmed the protection of CAPE against radiation-induced hepatotoxicity. TUNEL assay showed that CAPE pretreatment inhibited hepatocyte apoptosis. Moreover, CAPE inhibited the nuclear transport of NF-?B p65 subunit, decreased the level of tumor necrosis factor-?, nitric oxide and inducible nitric oxide synthase. Taken together, these results suggest that pretreatment with CAPE offers protection against radiation-induced hepatic injury. PMID:25704035

  15. Caffeic acid phenethyl ester (CAPE), an active component of propolis, inhibits Helicobacter pylori peptide deformylase activity.

    PubMed

    Cui, Kunqiang; Lu, Weiqiang; Zhu, Lili; Shen, Xu; Huang, Jin

    2013-05-31

    Helicobacter pylori (H. pylori) is a major causative factor for gastrointestinal illnesses, H. pylori peptide deformylase (HpPDF) catalyzes the removal of formyl group from the N-terminus of nascent polypeptide chains, which is essential for H. pylori survival and is considered as a promising drug target for anti-H. pylori therapy. Propolis, a natural antibiotic from honeybees, is reported to have an inhibitory effect on the growth of H. pylori in vitro. In addition, previous studies suggest that the main active constituents in the propolis are phenolic compounds. Therefore, we evaluated a collection of phenolic compounds derived from propolis for enzyme inhibition against HpPDF. Our study results show that Caffeic acid phenethyl ester (CAPE), one of the main medicinal components of propolis, is a competitive inhibitor against HpPDF, with an IC50 value of 4.02 ?M. Furthermore, absorption spectra and crystal structural characterization revealed that different from most well known PDF inhibitors, CAPE block the substrate entrance, preventing substrate from approaching the active site, but CAPE does not have chelate interaction with HpPDF and does not disrupt the metal-dependent catalysis. Our study provides valuable information for understanding the potential anti-H. pylori mechanism of propolis, and CAPE could be served as a lead compound for further anti-H. pylori drug discovery. PMID:23611786

  16. Caffeic acid phenethyl ester lessens disease symptoms in an experimental autoimmune uveoretinitis mouse model.

    PubMed

    Choi, Jae-Hyeog; Roh, Kug-Hwan; Oh, Hana; Park, Sol-Ji; Ha, Sung-Min; Kang, Mi Seon; Lee, Ji-Hyun; Jung, So Young; Song, Hyunkeun; Yang, Jae Wook; Park, SaeGwang

    2015-05-01

    Experimental autoimmune uveoretinitis (EAU) is an autoimmune disease that models human uveitis. Caffeic acid phenethyl ester (CAPE), a phenolic compound isolated from propolis, possesses anti-inflammatory and immunomodulatory properties. CAPE demonstrates therapeutic potential in several animal disease models through its ability to inhibit NF-?B activity. To evaluate these therapeutic effects in EAU, we administered CAPE in a model of EAU that develops after immunization with interphotoreceptor retinal-binding protein (IRBP) in B10.RIII and C57BL/6 mice. Importantly, we found that CAPE lessened the severity of EAU symptoms in both mouse strains. Notably, treated mice exhibited a decrease in the ocular infiltration of immune cell populations into the retina; reduced TNF-?, IL-6, and IFN-? serum levels: and inhibited TNF-? mRNA expression in retinal tissues. Although CAPE failed to inhibit IRBP-specific T cell proliferation, it was sufficient to suppress cytokine, chemokine, and IRBP-specific antibody production. In addition, retinal tissues isolated from CAPE-treated EAU mice revealed a decrease in NF-?B p65 and phospho-I?B?. The data identify CAPE as a potential therapeutic agent for autoimmune uveitis that acts by inhibiting cellular infiltration into the retina, reducing the levels of pro-inflammatory cytokines, chemokine, and IRBP-specific antibody and blocking NF-?B pathway activation. PMID:25795054

  17. Effects of Icosapent Ethyl (Eicosapentaenoic Acid Ethyl Ester) on Pharmacokinetic Parameters of Rosiglitazone in Healthy Subjects

    PubMed Central

    Braeckman, Rene A; Stirtan, William G; Soni, Paresh N

    2015-01-01

    Background Icosapent ethyl is a high-purity form of eicosapentaenoic acid ethyl ester approved to reduce triglyceride levels in adults with triglycerides ?500?mg/dL. Candidates for triglyceride-lowering therapy include patients with diabetes mellitus who may be receiving rosiglitazone. We assessed the effects of icosapent ethyl on the pharmacokinetic parameters of rosiglitazone. Methods Subjects received a single 8-mg oral dose of rosiglitazone alone and with oral icosapent ethyl 4?g/day in this open-label drug–drug interaction study. Pharmacokinetic end points included area under the concentration versus time curve from time zero to infinity (AUC0–inf) and maximum observed concentration (Cmax) for rosiglitazone with and without icosapent ethyl. Results Of 30 subjects enrolled, 28 completed the study. Icosapent ethyl 4?g/day at steady-state did not significantly change the single-dose AUC0–inf or Cmax of rosiglitazone 8?mg. Least squares geometric mean ratios (90% confidence interval) for AUC0–inf and Cmax of rosiglitazone given with icosapent ethyl versus rosiglitazone alone were 0.90 (87.00–93.40) and 1.01 (92.02–109.9), respectively. No serious adverse events were reported and no subject discontinued due to an adverse event. Conclusions At steady-state concentrations, icosapent ethyl did not inhibit the pharmacokinetics of rosiglitazone. Co-administration of icosapent ethyl and rosiglitazone was safe and well tolerated.

  18. Contribution to the analysis of the essential oil of Helichrysum italicum (Roth) G. Don. Determination of ester bonded acids and phenols.

    PubMed

    Masteli?, Josip; Politeo, Olivera; Jerkovi?, Igor

    2008-01-01

    The essential oil of Helichrysum italicum (Roth) G. Don (everlasting or Immortelle essential oil) was isolated by hydrodistillation and analysed by GC and GCMS. Forty four compounds were identified. The main components were alpha-pinene(12.8%), 2-methyl-cyclohexyl pentanoate (11.1 %), neryl acetate (10.4%), 1,7-di-epi-alpha-cedrene (6.8%) and other compounds. The oil was fractionated and ester-containing fraction was hydrolysed with KOH/H(2)SO(4). The liberated volatiles were analysed by GC and GC-MS: three phenols and twenty seven volatile carboxylic acids were identified[70% low fatty acids (C(2)-C(5)), 15% C(10)-C(12) acids and 15% other acids]. The main acids were acetic acid (24.3%) propanoic acid (17.2%), 2-methylpropanoic acid (11.4%),dodecanoic acid (8.7%), 2-methylbutanoic acid (8.3%), (Z)-2-methylbutenoic acid(5.1%) and decanoic acid (4.6%). With respect to the identified bonded carboxylic acids,the minimal number of esters in the oil was twenty seven, but their overall quantity was probably larger due to different possible combinations of alcohols with acids to form esters. On the other hand, only six main esters were identified in the oil before fractionation and hydrolysis. PMID:18463581

  19. Preparation of C18-functionalized Fe3O4@SiO2 core-shell magnetic nanoparticles for extraction and determination of phthalic acid esters in Chinese herb preparations.

    PubMed

    Guo, Bize; Ji, Shunli; Zhang, Feifang; Yang, Bingcheng; Gu, Jiangping; Liang, Xinmiao

    2014-11-01

    The extraction and determination of phthalic acid esters (PAEs) residue in Chinese herbal preparations (CHP) by C18-functionalized magnetic nanoparticles (C18-FS-MNP) has been firstly performed. It was synthesized through coating Fe3O4 nanoparticles with sodium silicate, followed by freeze-drying technique and then modified with C18 groups. C18-FS-MNPs prepared via freeze-drying technique were superior to those particles prepared via common vacuum drying method in terms of dispersion and extraction recovery. C18-FS-MNPs demonstrated obvious enrichment effect for four model PAEs and 478-627-fold enrichment factors were obtained. The limit of detection was <1.89ng/mL and relative standard deviation was ranging from 3.7 to 5.8%. It was successfully applied for determination of trace PAEs residue in CHP with good recoveries. PMID:25213260

  20. Antioxidant activity of phenolic compounds added to a functional emulsion containing omega-3 fatty acids and plant sterol esters.

    PubMed

    Espinosa, Raquel Rainho; Inchingolo, Raffaella; Alencar, Severino Matias; Rodriguez-Estrada, Maria Teresa; Castro, Inar Alves

    2015-09-01

    The effect of eleven compounds extracted from red propolis on the oxidative stability of a functional emulsion was evaluated. Emulsions prepared with Echium oil as omega 3 (?-3 FA) source, containing 1.63 g/100mL of ?-linolenic acid (ALA), 0.73 g/100 mL of stearidonic acid (SDA) and 0.65 g/100mL of plant sterol esters (PSE) were prepared without or with phenolic compounds (vanillic acid, caffeic acid, trans-cinnamic acid, 2,4-dihydroxycinnamic acid, p-coumaric acid, quercetin, trans-ferulic acid, trans,trans-farnesol, rutin, gallic acid or sinapic acid). tert-Butylhydroquinone and a mixture containing ascorbic acid and FeSO4 were applied as negative and positive controls of the oxidation. Hydroperoxide, thiobarbituric acid reactive substances (TBARS), malondialdehyde and phytosterol oxidation products (POPs) were evaluated as oxidative markers. Based on hydroperoxide and TBARS analysis, sinapic acid and rutin (200 ppm) showed the same antioxidant activity than TBHQ, representing a potential alternative as natural antioxidant to be applied in a functional emulsion containing ?-3 FA and PSE. PMID:25842314

  1. Preparation of biodegradable networks by photo-crosslinking lactide, ?-caprolactone and trimethylene carbonate-based oligomers functionalized with fumaric acid monoethyl ester

    Microsoft Academic Search

    Dirk W. Grijpma; Qingpu Hou; Jan Feijen

    2005-01-01

    Biodegradable polymer networks were prepared from fumaric acid derivatives of oligomeric esters. Photo-crosslinkable macromers were prepared by reacting star-shaped hydroxyl-group terminated lactide, ?-caprolactone and trimethylene carbonate based oligomers and fumaric acid monoethyl ester in the presence of N,N-dicyclohexylcarbodiimide and 4-dimethylamino pyridine at room temperature. The functionalization method is facile and suited for many hydroxyl-terminated oligomers.The reactivity of the fumarate end

  2. Relative rates of hydrolysis by rat pancreatic lipase of esters of C2-C18 fatty acids with C1-C18 primary n-alcohols

    Microsoft Academic Search

    F. H. MATTSON; R. A. VOLPENHEIN

    The rate at which rat pancreatic lipase (glycerol-ester hydrolase, EC 3.1.1.3) hydrolyzes the esters of primary n-alcohols containing from 1 to 18 carbon atoms with fatty acids containing from 2 to 18 carbon atoms was deter- mined. The speed of hydrolysis was influenced, apparently independently, by both the acyl and the alkyl chains. With respect to the fatty acid moiety,

  3. Anaerobic degradation of phthalic acid esters during digestion of municipal solid waste under landfilling conditions.

    PubMed

    Ejlertsson, J; Meyerson, U; Svensson, B H

    1996-08-01

    Anaerobic microorganisms in municipal solid waste samples from laboratory-scale landfill reactors and a pilot-plant biogas digestor were investigated with the aim of assessing their ability to transform four commercially used phthalic acid esters (PAEs) and phthalic acid (PA). The PAEs studied were diethyl phthalate (DEP), butylbenzyl phthalate (BBP), dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP). No biological transformation of DEHP could be detected in any of the experiments. Together with waste samples from the simulated landfilling conditions, the PAEs (except DEHP) were hydrolytically transformed to their corresponding monoesters. These accumulated as end products, and in most cases they were not further degraded. During incubation with waste from the biogas digestor, the PAEs (except DEHP) were completely degraded to methane and carbon dioxide. The influence of the landfill development phase on the transformations was investigated utilizing PA and DEP as model substances. We found that during both the intense and stable methanogenic (but not the acidogenic) phases, the microorganisms in the samples had the potential to transform PA. A shorter lag phase was observed for the PA transformation in the samples from the stable methanogenic phase as compared with earlier phases. This indicates an increased capacity to degrade PA during the aging phases of the municipal solid waste in landfills. No enhancement of the DEP transformation could be observed as conditions in the methanogenic landfill model changed over a year's time. The results indicate that microorganisms developing in a methanogenic landfill environment have a substantially lower potential to degrade compared with those developing in a biogas reactor. PMID:8987892

  4. meso-Ester and carboxylic acid substituted BODIPYs with far-red and near-infrared emission for bioimaging applications.

    PubMed

    Ni, Yong; Zeng, Lintao; Kang, Nam-Young; Huang, Kuo-Wei; Wang, Liang; Zeng, Zebing; Chang, Young-Tae; Wu, Jishan

    2014-02-17

    A series of meso-ester-substituted BODIPY derivatives 1-6 are synthesized and characterized. In particular, dyes functionalized with oligo(ethylene glycol) ether styryl or naphthalene vinylene groups at the ? positions of the BODIPY core (3-6) become partially soluble in water, and their absorptions and emissions are located in the far-red or near-infrared region. Three synthetic approaches are attempted to access the meso-carboxylic acid (COOH)-substituted BODIPYs 7 and 8 from the meso-ester-substituted BODIPYs. Two feasible synthetic routes are developed successfully, including one short route with only three steps. The meso-COOH-substituted BODIPY 7 is completely soluble in pure water, and its fluorescence maximum reaches around 650?nm with a fluorescence quantum yield of up to 15?%. Time-dependent density functional theory calculations are conducted to understand the structure-optical properties relationship, and it is revealed that the Stokes shift is dependent mainly on the geometric change from the ground state to the first excited singlet state. Furthermore, cell staining tests demonstrate that the meso-ester-substituted BODIPYs (1 and 3-6) and one of the meso-COOH-substituted BODIPYs (8) are very membrane-permeable. These features make these meso-ester- and meso-COOH-substituted BODIPY dyes attractive for bioimaging and biolabeling applications in living cells. PMID:24515608

  5. Synthesis, Aqueous Reactivity, and Biological Evaluation of Carboxylic Acid Ester-Functionalized Platinum–Acridine Hybrid Anticancer Agents

    PubMed Central

    Graham, Leigh A.; Suryadi, Jimmy; West, Tiffany K.; Kucera, Gregory L.; Bierbach, Ulrich

    2012-01-01

    The synthesis of platinum–acridine hybrid agents containing carboxylic acid ester groups is described. The most active derivatives and the unmodified parent compounds showed up to 6-fold higher activity in ovarian cancer (OVCAR-3) and breast cancer (MCF-7, MDA-MB-23) cell lines than cisplatin. Inhibition of cell proliferation at nanomolar concentrations was observed in pancreatic (PANC-1) and non-small cell lung cancer cells (NSCLC, NCI-H460) of 80- and 150-fold, respectively. Introduction of the ester groups did not affect the cytotoxic properties of the hybrids, which form the same monofunctional–intercalative DNA adducts as the parent compounds, as demonstrated in a plasmid unwinding assay. In-line high-performance liquid chromatography and electrospray mass spectrometry (LC-ESMS) shows that the ester moieties undergo platinum-mediated hydrolysis in a chloride concentration-dependent manner to form carboxylate chelates. Potential applications of the chloride-sensitive ester hydrolysis as a self-immolative release mechanism for tumor-selective delivery of platinum–acridines are discussed. PMID:22871158

  6. Lewis acid catalysed methylation of N-(9H-fluoren-9-yl)methanesulfonyl (Fms) protected lipophilic ?-amino acid methyl esters.

    PubMed

    Leggio, Antonella; Alò, Danila; Belsito, Emilia Lucia; Di Gioia, Maria Luisa; Romio, Emanuela; Siciliano, Carlo; Liguori, Angelo

    2015-08-01

    This work reports an efficient Lewis acid catalysed N-methylation procedure of lipophilic ?-amino acid methyl esters in solution phase. The developed methodology involves the use of the reagent system AlCl3 /diazomethane as methylating agent and ?-amino acid methyl esters protected on the amino function with the (9H-fluoren-9-yl)methanesulfonyl (Fms) group. The removal of Fms protecting group is achieved under the same conditions to those used for Fmoc removal. Thus the Fms group can be interchangeable with the Fmoc group in the synthesis of N-methylated peptides using standard Fmoc-based strategies. Finally, the absence of racemization during the methylation reaction and the removal of Fms group were demonstrated by synthesising a pair of diastereomeric dipeptides. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. PMID:25921656

  7. Very-long-chain 3-hydroxy fatty acids, 3-hydroxy fatty acid methyl esters and 2-alkanols from cuticular waxes of Aloe arborescens leaves.

    PubMed

    Racovita, Radu C; Peng, Chen; Awakawa, Takayoshi; Abe, Ikuro; Jetter, Reinhard

    2015-05-01

    The present work aimed at a comprehensive chemical characterization of the cuticular wax mixtures covering leaves of the monocot species Aloe arborescens. The wax mixtures were found to contain typical aliphatic compound classes in characteristic chain length distributions, including alkanes (predominantly C31), primary alcohols (predominantly C28), aldehydes (predominantly C32), fatty acid methyl esters (predominantly C28) and fatty acids (bimodal distribution around C32 and C28). Alkyl esters ranging from C42 to C52 were identified, and found to mainly contain C28 alcohol linked to C16-C20 acids. Three other homologous series were identified as 3-hydroxy fatty acids (predominantly C28), their methyl esters (predominantly C28), and 2-alkanols (predominantly C31). Based on structural similarities and homolog distributions, the biosynthetic pathways leading to these novel wax constituents can be hypothesized. Further detailed analyses showed that the A. arborescens leaf was covered with 15?g/cm(2) wax on its adaxial side and 36?g/cm(2) on the abaxial side, with 3:2 and 1:1 ratios between epicuticular and intracuticular wax layers on each side, respectively. Terpenoids were found mainly in the intracuticular waxes, whereas very-long-chain alkanes and fatty acids accumulated to relatively high concentrations in the epicuticular wax, hence near the true surface of the leaf. PMID:25200334

  8. Acidic 1,3-propanediaminetetraacetato lanthanides with luminescent and catalytic ester hydrolysis properties

    NASA Astrophysics Data System (ADS)

    Chen, Mao-Long; Shi, Yan-Ru; Yang, Yu-Chen; Zhou, Zhao-Hui

    2014-11-01

    In acidic solution, a serials of water-soluble coordination polymers (CPs) were isolated as zonal 1D-CPs 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H3pdta)(H2O)5]n·2Cln·3nH2O [Ln=La, 1; Ce, 2; Pr, 3; Nd, 4; Sm, 5] (1,3-H4pdta=1,3-propanediaminetetraacetic acid, C11H18N2O8) in high yields. When 1 eq. mol potassium hydroxide was added to the solutions of 1D-CPs, respectively, two 1D-CPs [Ln(1,3-H2pdta)(H2O)3]n·Cln·2nH2O [Ln=Sm, 6; Gd, 7] were isolated at room temperature and seven 2D-CPs [Ln(1,3-H2pdta)(H2O)2]n·Cln·2nH2O [Ln=La, 8; Ce, 9; Pr, 10; Nd, 11; Sm, 12; Eu, 13; Gd, 14] were isolated at 70 °C. When the crystals of 1-4 were hydrothermally heated at 180 °C with 1-2 eq. mol potassium hydroxide, four 3D-CPs [Ln(1,3-Hpdta)]n·nH2O [Ln=La, 15; Ce, 16; Pr, 17; Nd, 18] were obtained. The two 2D-CPs [Ln(1,3-Hpdta)(H2O)]n·4nH2O (Sm, 19; Eu, 20) were isolated in similar reaction conditions. With the increments of pH value in the solution and reaction temperature, the structure becomes more complicated. 1-5 are soluble in water and 1 was traced by solution 13C{1H} NMR technique, the water-soluble lanthanides 1 and 5 show catalytic activity to ester hydrolysis reaction respectively, which indicate their important roles in the hydrolytic reaction. The europium complexes 13 and 20 show visible fluorescence at an excitation of 394 nm. The structure diversity is mainly caused by the variation of coordinated ligand in different pH values and lanthanide contraction effect. Acidic conditions are favorable for the isolations of lanthanide complexes in different structures and this may helpful to separate different lanthanides. The thermal stability investigations reveal that acidic condition is favorable to obtain the oxides at a lower temperature.

  9. Biochemical mechanism of Caffeic Acid Phenylethyl Ester (CAPE) selective toxicity towards melanoma cell lines

    PubMed Central

    Kudugunti, Shashi K.; Vad, Nikhil M.; Whiteside, Amanda J.; Naik, Bhakti U.; Yusuf, Mohd. A.; Srivenugopal, Kalkunte S.; Moridani, Majid Y.

    2010-01-01

    In the current work, we investigated the in-vitro biochemical mechanism of caffeic acid phenylethyl ester (CAPE) toxicity and eight hydroxycinnamic/caffeic acid derivatives in-vitro, using tyrosinase enzyme as a molecular target in human SK-MEL-28 melanoma cells. Enzymatic reaction models using tyrosinase/O2 and HRP/H2O2 were used to delineate the role of one- and two-electron oxidation. Ascorbic acid (AA), NADH and GSH depletion were used as markers of quinone formation and oxidative stress in CAPE induced toxicity in melanoma cells. Ethylenediamine, an o-quinone trap, prevented the formation of o-quinone and oxidations of AA and NADH mediated by tyrosinase bioactivation of CAPE. The IC50 of CAPE towards SK-MEL-28 melanoma cells was 15?M. Dicoumarol, a diaphorase inhibitor, and 1-bromoheptane, a GSH depleting agent, increased CAPE’s toxicity towards SK-MEL-28 cells indicating quinone formation played an important role in CAPE induced cell toxicity. Cyclosporin-A and trifluoperazine, inhibitors of the mitochondrial membrane permeability transition pore (PTP), prevented CAPE toxicity towards melanoma cells. We further investigated the role of tyrosinase in CAPE toxicity in the presence of a shRNA plasmid, targeting tyrosinase mRNA. Results from tyrosinase shRNA experiments showed that CAPE led to negligible anti-proliferative effect, apoptotic cell death and ROS formation in shRNA plasmid treated cells. Furthermore, it was also found that CAPE selectively caused escalation in the ROS formation and intracellular GSH (ICG) depletion in melanocytic human SK-MEL-28 cells which express functional tyrosinase. In contrast, CAPE did not lead to ROS formation and ICG depletion in amelanotic C32 melanoma cells, which do not express functional tyrosinase. These findings suggest that tyrosinase plays a major role in CAPE’s selective toxicity towards melanocytic melanoma cell lines. Our findings suggest that the mechanisms of CAPE toxicity in SK-MEL-28 melanoma cells mediated by tyrosinase bioactivation of CAPE included quinone formation, ROS formation, intracellular GSH depletion and induced mitochondrial toxicity. PMID:20685355

  10. Unexpected racemization of proline or hydroxy-proline phenacyl ester during coupling reactions with Boc-amino acids.

    PubMed

    Kuroda, H; Kubo, S; Chino, N; Kimura, T; Sakakibara, S

    1992-08-01

    When L-proline or O-benzyl-trans-4-hydroxy-L-proline phenacyl ester was coupled with Boc-amino acids in dimethylformamide using water-soluble carbodiimide (WSCI) in the presence of anhydrous 1-hydroxybenzotriazole (HOBt) as coupling reagents, extensive racemization was observed at the C alpha of the proline or hydroxy-proline residue. The extent of racemization was measured by HPLC after the coupling with Boc-L-Leu-OH in the presence or absence of HOBt. The extent of racemization increased when HOBt was added to the reaction mixture, but greatly decreased when it was not, indicating that HOBt was needed for inducing racemization. Almost no racemization was observed when the coupling reaction was carried out by the mixed anhydride procedure in tetrahydrofuran or by the carbodiimide method in dichloromethane without using HOBt. In the case of coupling reactions with ordinary L-amino acid phenacyl esters, no racemization was observed. Examination of some model systems yielded sufficient evidence to prove that HOBt is an efficient catalyst for racemizing proline or hydroxy-proline phenacyl ester not only in the stage of cyclic intermediate formation but also in the opening of the ring structure. Thus, the racemization reaction was found to be closely related to the formation of the cyclic carbinol-amine derivative. PMID:1446968

  11. 2-Chloro-1,3-propanediol (2-MCPD) and its fatty acid esters: cytotoxicity, metabolism, and transport by human intestinal Caco-2 cells.

    PubMed

    Buhrke, Thorsten; Frenzel, Falko; Kuhlmann, Jan; Lampen, Alfonso

    2014-10-30

    The food contaminants 3-chloro-1,2-propanediol (3-MCPD) and 3-MCPD fatty acid esters have attracted considerable attention in the past few years due to their toxic properties and their occurrence in numerous foods. Recently, significant amounts of the isomeric compounds 2-chloro-1,3-propanediol (2-MCPD) fatty acid esters have been detected in refined oils. Beside the interrogation which toxic effects might be related to the core compound 2-MCPD, the key question from the risk assessment perspective is again-as it was discussed for 3-MCPD fatty acid esters before-to which degree these esters are hydrolyzed in the gut, thereby releasing free 2-MCPD. Here, we show that free 2-MCPD but not 2-MCPD fatty acid esters were able to cross a monolayer of differentiated Caco-2 cells as an in vitro model for the human intestinal barrier. Instead, the esters were hydrolyzed by the cells, thereby releasing free 2-MCPD which was neither absorbed nor metabolized by the cells. Cytotoxicity assays revealed that free 2-MCPD as well as free 3-MCPD was not toxic to Caco-2 cells up to a level of 1 mM, whereas cellular viability was slightly decreased in the presence of a few 2-MCPD and 3-MCPD fatty acid esters at concentrations above 10 µM. The observed cytotoxic effects correlated well with the induction of caspase activity and might be attributed to the induction of apoptosis by free fatty acids which were released from the esters in the presence of Caco-2 cells. PMID:25354796

  12. Saponification rates of esters in aqueous dioxane 

    E-print Network

    Christian, John Donald

    1952-01-01

    ........................... .......... 9 Methyl and Ethyl Esters of n-Valeric Acid . . . . 9 Methyl and Ethyl Esters of Isovaleric Acid . . . 10 Methyl and Ethyl Esters of Methylethylacetic A c i d ...................................... 11 Methyl and Ethyl Esters.... XV. I. ? ? ? ? ? ?Physical Constants of 3sters . . mple Calculation for Methyl n-Valerate (25?)Ou Rate Constant Values and the Average Value (Methyl Esters) ...................... Rate Constant Values and the Average Value (Ethyl Esters...

  13. Synthesis and properties of methyl 5-(1? R,2? S)-(2-octadecylcycloprop-1-yl)pentanoate and other ?-19 chiral cyclopropane fatty acids and esters related to mycobacterial mycolic acids

    Microsoft Academic Search

    Geoffrey D Coxon; Juma’a R Al Dulayymi; Caroline Morehouse; Patrick J Brennan; Gurdyal S Besra; Mark S Baird; David E Minnikin

    2004-01-01

    A 23–26-carbon chain length range of ?-19 (1?R,2?S) cyclopropane fatty acids, related to mycobacterial mycolic acids, has been prepared. The key cyclopropyl intermediate, (1?R,2?S)-(Z)-1-formyl-2-octadecylcyclopropane, underwent Wittig chemistry with various reagents to provide vinylic precursors, which were selectively reduced to the corresponding saturated ?-19 cyclopropane fatty acids or esters. The 24-carbon ?-19 cyclopropane ester was made by chain elongation of the

  14. Caffeic Acid Phenethyl Ester as a Protective Agent against Nephrotoxicity and/or Oxidative Kidney Damage: A Detailed Systematic Review

    PubMed Central

    Akyol, Sumeyya; Ugurcu, Veli; Altuntas, Aynur; Hasgul, Rukiye; Cakmak, Ozlem

    2014-01-01

    Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been attracting the attention of different medical and pharmaceutical disciplines in recent years because of its antioxidant, anti-inflammatory, antiproliferative, cytotoxic, antiviral, antifungal, and antineoplastic properties. One of the most studied organs for the effects of CAPE is the kidney, particularly in the capacity of this ester to decrease the nephrotoxicity induced by several drugs and the oxidative injury after ischemia/reperfusion (I/R). In this review, we summarized and critically evaluated the current knowledge regarding the protective effect of CAPE in nephrotoxicity induced by several special medicines such as cisplatin, doxorubicin, cyclosporine, gentamycin, methotrexate, and other causes leading to oxidative renal injury, namely, I/R models and senility. PMID:25003138

  15. Immunomodulatory effect of caffeic acid phenethyl ester in Balb/c mice.

    PubMed

    Park, Jae Hyun; Lee, Jong Kwon; Kim, Hyung Soo; Chung, Seung Tae; Eom, Juno H; Kim, Kyung A; Chung, Se Jin; Paik, Soon Young; Oh, Hye Young

    2004-03-01

    Caffeic acid phenethyl ester (CAPE), an the active component of propolis, is known to have anticarcinogenic, antiviral and various biological activities; however, the effect of CAPE on the immunomodulatory activity in vivo remains unknown. We have investigated the effect of CAPE on the immune system in female Balb/c mice. CAPE (0, 5, 10, 20 mg/kg) was given to mice orally for 14 days. Immunomodulatory activity was evaluated by assessment of body and organ weight, lymphocyte blastogenesis, plaque-forming cell (PFC) assay, lymphocyte subpopulation by flow cytometry and cytokine production. Even though the change of body weight was not observed in CAPE-administered group, thymus weight and/or cellularity of thymus and spleen are decreased at the all dose groups of CAPE (5, 10, 20 mg/kg). On the other hand, CAPE had no effect on B lymphocyte proliferation induced by lipopolysaccharide (LPS) but increased T lymphocyte blastogenesis induced by concanavalin A (Con A) at the dose of 20 mg/kg. In the case of lymphocyte subpopulation, the population of T and B cells was not changed but CD4(+) T cell subsets are significantly increased in exposure to CAPE. The antibody responses to T lymphocyte dependent antigen, sheep red blood cell and keyhole limpet hemocyanin (KLH) were increased more than 10 mg/kg in CAPE-treated group. Likewise, the cytokine, IL-2, IL-4 and IFN-gamma were significantly increased at the dose of 20 mg/kg CAPE group. These results suggest that CAPE could have immunomodulatory effects in vivo. PMID:15037220

  16. Effects of caffeic acid phenethyl ester on palatal mucosal defects and tooth extraction sockets

    PubMed Central

    Günay, Ahmet; Arpa?, Osman Fatih; Atilgan, Serhat; Yaman, Ferhan; Atalay, Yusuf; Acikan, ?zzet

    2014-01-01

    Aim The purpose of this study was to evaluate the effects of caffeic acid phenethyl ester (CAPE) on palatal mucosal defects and tooth extraction sockets in an experimental model. Materials and methods Forty-two male Sprague-Dawley rats with a mean age of 7 weeks and weighing 280–490 g were used in this study. The rats were randomly divided into two groups: group A (the control group, n=21) and group B (the experimental group, n=21). Under anesthesia with ketamine (8 mg/100 g, intraperitoneally), palatal mucosal defects were created and tooth extraction was performed in the rats in groups A and B. Group A received no treatment, whereas group B received CAPE. CAPE was injected daily (10 ?mol/kg, intraperitoneally). The rats were killed on days 7, 14, and 30 after the procedures. Palatal mucosa healing and changes in bone tissue and fibrous tissue were evaluated histopathologically. Result Pairwise comparisons showed no statistically significant difference between days 7 and 14 in either group (P>0.05). At day 30, bone healing was significantly better in group B (CAPE) than in group A (control) (P<0.05). Fibrinogen levels at day 30 were significantly higher in group A (control) than in group B (CAPE) (P<0.05). Pairwise comparisons showed no statistically significant difference in palatal mucosa healing levels between days 7 and 14 in both groups (P>0.05). Conclusion In conclusion, the findings of this study suggest that CAPE can significantly improve tooth socket healing. PMID:25364232

  17. Phthalic Acid Esters in Soils from Vegetable Greenhouses in Shandong Peninsula, East China

    PubMed Central

    Chai, Chao; Cheng, Hongzhen; Ge, Wei; Ma, Dong; Shi, Yanxi

    2014-01-01

    Soils at depths of 0 cm to 10 cm, 10 cm to 20 cm, and 20 cm to 40 cm from 37 vegetable greenhouses in Shandong Peninsula, East China, were collected, and 16 phthalic acid esters (PAEs) were detected using gas chromatography-mass spectrometry (GC-MS). All 16 PAEs could be detected in soils from vegetable greenhouses. The total of 16 PAEs (?16PAEs) ranged from 1.939 mg/kg to 35.442 mg/kg, with an average of 6.748 mg/kg. Among four areas, including Qingdao, Weihai, Weifang, and Yantai, the average and maximum concentrations of ?16PAEs in soils at depths of 0 cm to 10 cm appeared in Weifang, which has a long history of vegetable production and is famous for extensive greenhouse cultivation. Despite the different concentrations of ?16PAEs, the PAE compositions were comparable. Among the 16 PAEs, di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), di-n-butyl phthalate (DnBP), and diisobutyl phthalate (DiBP) were the most abundant. Compared with the results on agricultural soils in China, soils that are being used or were used for vegetable greenhouses had higher PAE concentrations. Among PAEs, dimethyl phthalate (DMP), diethyl phthalate (DEP) and DnBP exceeded soil allowable concentrations (in US) in more than 90% of the samples, and DnOP in more than 20%. Shandong Peninsula has the highest PAE contents, which suggests that this area is severely contaminated by PAEs. PMID:24747982

  18. Protective Effect of Caffeic Acid Phenethyl Ester (CAPE) on Amiodarone-Induced Pulmonary Fibrosisin Rat

    PubMed Central

    Zaeemzadeh, Narjes; Hemmati, Aliasghar; Arzi, Ardeshir; Jalali, Mohammadtaha; Rashidi, Iran

    2011-01-01

    Treatment with amiodarone, a commonly prescribed antidysrhythmic agent, is associated with pulmonary fibrosis (PF) which is a commonly progressive and untreatable disease. Caffeic acid phenethyl ester (CAPE) is a phenolic antioxidant and an active anti-inflammatory , anticancer, antimicrobial and antioxidant component of propolis (bee glue; a resinous hive product collected by honey bees). In the current study, the effects of CAPE on amiodarone-induced pulmonary fibrosis in rat were investigated. Male rats were divided in to 4 groups. The first group only received amiodarone (6.25 mg/Kg) on first and third day. The second group received only vehicle (distilled water) with the same volume and in the same time as the first group. The third and fourth groups received amiodarone and were treated with CAPE , 5 and 10 µmol /day respectively, from 2 days before the first dose of amiodarone and until 21 days after the second dose of amiodarone. At the end of treatment course, lung tissue was removed for histopathology and biochemical evaluations. Malondialdehyde (MDA) concentration, myeloperoxidase MPO) and super oxide dismutase (SOD) activities were determined in lung tissue. Histopathological evaluation was performed using light microscopy. MDA level and the activity of myeloperoxidase and superoxide dismutase enzymes significantly decreased in the group which was treated with CAPE (5 µmol/Kg). However, 10 µmol/Kg CAPE had not such an effect. Both doses of CAPE could histopathologically reduce the fibrogenic effects of amiodarone . CAPE was shown to be effective in reducing amiodarone-induced pulmonary fibrosis with the dose of 5 µmol/Kg. PMID:24250361

  19. Effects of Potamogeton crispus L. on the fate of phthalic acid esters in an aquatic microcosm.

    PubMed

    Chi, Jie; Yang, Qing

    2012-05-15

    To study the effects of submerged hydrophytes on the fate of dibutyl phthalate (DBP) and di-2-ethylexyl phthalate (DEHP) in the aquatic environment, a Potamogeton crispus L. (P. crispus) microcosm was constructed. A four-compartment (i.e., water, plant, non-rhizosphere and rhizosphere sediments) level IV fugacity model was established and applied to the simulation experiments in the microcosm. Data obtained from model calculations were in good agreement with those from the experiments. Results of the model calculations showed that the total residues of DBP and DEHP in the microcosm with P. crispus were 39.7% and 19.8% lower than those in the microcosm without P. crispus. The overall biodegradation fluxes of DBP and DEHP in the microcosm with P. crispus increased by 4.7% and 12.3%, respectively, and meanwhile, advective outflow decreased. In the presence of P. crispus, a large fraction of loaded DBP and DEHP (17.7% and 29.0%) transferred to plants, and then to the rhizosphere. 4.8% and 28.0% of loaded DBP and DEHP were removed by biodegradation in P. crispus, and the remaining 12.9% and 1.0% were by biodegradation in rhizosphere sediment which was 3.6% of the total sediment. This finding demonstrates that P. crispus can substantially reduce the accumulation of phthalic acid esters (PAEs) in the experiment system and enhance the removal of PAEs. The enhancement of PAE removal is related to the biodegradation of PAEs in P. crispus, especially for the more hydrophobic DEHP. For the less hydrophobic DBP, biodegradation in the rhizosphere also plays a key role. In addition to nutrient uptake from sediment, transport process between P. crispus and the rhizosphere has also a significant influence on the distribution and fate of PAEs in the aquatic environment. PMID:22405677

  20. Cannabinoid receptor binding and agonist activity of amides and esters of arachidonic acid.

    PubMed

    Pinto, J C; Potié, F; Rice, K C; Boring, D; Johnson, M R; Evans, D M; Wilken, G H; Cantrell, C H; Howlett, A C

    1994-09-01

    The cannabinoid receptor in brain (CB1) specifically binds delta 9-tetrahydrocannabinol, the predominant central nervous system-active component of marijuana. An eicosanoid found in brain, N-(2-hydroxyethyl)arachidonylamide (anandamide), binds to CB1 with similar affinity. This report considers structure-activity requirements for a series of novel amides and rigid hairpin conformations typified by N-(2-hydroxyethyl)prostaglandin amides, assayed with phenylmethylsulfonyl fluoride inactivation of esterases/amidases. Arachidonyl esters were 30-fold less potent than N-(2-hydroxyethyl)arachidonylamide, showing a rank order of potency of methyl = ethyl > propyl = isopropyl. Within the N-(hydroxyalkyl)arachidonylamide series, a one-carbon increase in chain length increased the potency 2-fold, but continued extension decreased affinity. Substituting the amide for the N-(2-hydroxyethyl)amide function produced a 4-fold loss of affinity. The N-(propyl)-, N-(butyl)-, and N-(benzyl)arachidonylamide derivatives exhibited a 3-fold increase, no change, and a 5-fold decrease, respectively, in affinity, compared with N-(2-hydroxyethyl)arachidonylamide. Both the methoxy ether and the formamide derivatives suffered > 20-fold loss of potency, compared with N-(2-hydroxyethyl)arachidonylamide. N-(2-Aminoethyl)arachidonylamide interacted poorly with CB1. At 100 microM, N-(2-hydroxyethyl)amide analogs of prostaglandin E2, A2, B2, and B1 failed to alter [3H]CP55940 binding to CB1. N-(2-Hydroxyethyl)arachidonylamide inhibited adenylate cyclase with lesser potency but with similar efficacy, compared with desacetyllevonantradol. Extending the length of the hydroxyalkyl moiety by one carbon increased the apparent potency by 1 order of magnitude. The N-(propyl) derivative exhibited a 5-fold greater potency than did the N-(2-hydroxyethyl) analog. It appears that the bulk and length of the moiety appended to arachidonic acid are more important determinants of affinity for CB1 than is hydrogen-bonding capability. PMID:7935333

  1. Metabolism of fatty acid in yeast: characterisation of beta-oxidation and ultrastructural changes in the genus Sporidiobolus sp. cultivated on ricinoleic acid methyl ester.

    PubMed

    Feron, Gilles; Blin-Perrin, Caroline; Krasniewski, Isabelle; Mauvais, Geneviève; Lherminier, Jeannine

    2005-09-01

    Cell structure modifications and beta-oxidation induction were monitored in two strains of Sporidiobolus, Sp. Ruinenii and Sp. pararoseus after cultivation on ricinoleic acid methyl ester. Ultrastructural observations of the yeast before and after cultivation on fatty acid esters did not reveal major modifications in Sp. ruinenii. Unexpectedly, in Sp. pararoseus a proliferation of the mitochondrion was observed. After induction, Sp. ruinenii principally exhibited an increase in the activities of acyl-CoA oxidase (ACO), hydroxyacyl-CoA deshydrogenase (HAD), thiolase and catalase. In contrast, Sp. pararoseus lacked ACO and catalase activities, but an increase in acyl-CoA deshydrogenase (ACDH) and enoyl-CoA hydratase (ECH) activity was observed. These data suggest that in Sp. ruinenii, beta-oxidation is preferentially localized in the microbody, whereas in Sp. pararoseus it might be localized in the mitochondria. PMID:16043312

  2. EXTRACTION OF RARE EARTH METALS WITH 2-ETHYLHEXYL PHOSPHONIC ACID MONO2-ETHYLHEXYL ESTER IN THE PRESENCE OF DIETHYLENETRIAMINEPENTAACETIC ACID IN AQUEOUS PHASE

    Microsoft Academic Search

    Fukiko Kubota; Masahiro Goto; Fumiyuki Nakashio

    1993-01-01

    The extraction equilibria of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (commercial name, PC-88A, henceforth abbreviated as HR) dissolved in n-heptane were measured at 303 K. It was found that rare earth metals are extracted with the dimer of the extractant, (HR)2, as follows.The extraction equilibrium constants of metals were obtained and compared with the extraction equilibrium constants

  3. DFT study of the mechanism and origin of enantioselectivity in chiral BINOL-phosphoric acid catalyzed transfer hydrogenation of ketimine and ?-imino ester using benzothiazoline.

    PubMed

    Shibata, Yukihiro; Yamanaka, Masahiro

    2013-04-19

    Benzothiazoline is an efficient reducing agent for the chiral BINOL-phosphoric acid catalyzed enantioselective transfer hydrogenation of ketimines and ?-imino esters to afford the corresponding amines with high enantioselectivities. DFT studies (M05-2X/6-31G*//ONIOM(B3LYP/6-31G*:HF/3-21G)) revealed the reaction mechanism and the origin of the high enantioselectivity in the present BINOL-phosphoric acid catalyzed transfer hydrogenation of ketimines and ?-imino esters using benzothiazoline. The reaction mechanism is similar to that reported in the asymmetric transfer hydrogenation of ketimines using Hantzsch ester. Phosphoric acid simultaneously activates ketimine (?-imino ester) and benzothiazoline to form cyclic transition structures. The high enantioselectivity is attributed to the steric interaction between the substituents at the 3,3'-positions of BINOL-phosphoric acid and substrates. In contrast to the C2-symmetrical Hantzsch ester, the readily tunable 2-aryl substituent of unsymmetrical benzothiazoline plays a significant role in the steric interaction, influencing the asymmetric induction. This feature is responsible for the advantage of benzothiazoline over Hantzsch ester. PMID:23521654

  4. Chromatographic studies on oxidative and thermal fatty acid dimers

    Microsoft Academic Search

    C. D. Evans; D. G. McConnell; E. N. Frankel; J. C. Cowan

    1965-01-01

    A chromatographic study was carried out to investigate the nature of polymeric products in edible oils. Dimers from low-temp\\u000a oxidation of methyl linoleate were compared with thermal dimers from high-temp polymerization of conjugated methyl linoleate.\\u000a The distilled dimers were subjected to liquid-partition chromatographic separations on silicic acid columns as methyl esters,\\u000a as free acids, and as methyl esters prepared by

  5. Method of making alkyl esters

    DOEpatents

    Elliott, Brian (Wheat Ridge, CO)

    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.

  6. Fatty acid proportions in cholesterol esters and risk of premature death from cancer in middle aged French men.

    PubMed Central

    Zureik, M.; Ducimetière, P.; Warnet, J. M.; Orssaud, G.

    1995-01-01

    OBJECTIVE--To assess the association of proportions of fatty acids in cholesterol esters with the risk of premature death from cancer in middle aged men. DESIGN--Prospective cohort study. SETTING--Paris, France. SUBJECTS--3277 working men aged 36-52 in 1981-5. MAIN OUTCOME MEASURES--Cancer mortality during an average of 9.3 years of follow up. RESULTS--59 men died of cancer during follow up. The age adjusted relative risks for men in the highest thirds of the distribution of the proportions of linoleic, palmitoleic, and oleic acid in cholesterol esters as compared with those in the corresponding lowest thirds were 0.16 (95% confidence interval 0.05 to 0.51), 3.39 (1.63 to 7.05), and 4.22 (1.95 to 9.12), respectively. Adjustment for and stratification by smoking, alcohol consumption, serum cholesterol concentration, and body mass index did not alter the results. At the time of examination subjects with cancer had a lower intake of polyunsaturated fats, assessed by 24 hour recall, than those without cancer (13.2 v 17.4 g/day, P < 0.01). CONCLUSIONS--Monounsaturated and polyunsaturated fatty acids of cholesterol esters are strong biological markers that predict premature death from cancer in French men. Consistently, intake of polyunsaturated fats did not seem to increase the risk of death from cancer. The association of biological markers of dietary fat intake with incidence of and mortality from cancer should be investigated prospectively in other populations. PMID:7496232

  7. Control and analysis of alkyl esters of alkyl and aryl sulfonic acids in novel active pharmaceutical ingredients (APIs).

    PubMed

    Elder, D P; Teasdale, A; Lipczynski, A M

    2008-01-01

    This article reviews current regulatory guidelines and relevant scientific literature pertaining to the control and analysis of potential genotoxic impurities (PGIs) in new active pharmaceutical ingredients (APIs) with specific reference to a certain sub-class of PGIs, namely alkyl esters of alkyl and aryl sulfonic acids. Sulfonic acids are very important in pharmaceutical R&D employed both as counter-ions in the formation of acid-addition salts and also as reagents and catalysts in the synthesis of new drug substances. The article reviews the evolution of analytical methodology from early studies in the mid 1970s through development of direct injection GC and HPLC methods to liquid-liquid/solid phase extraction and headspace based techniques coupled to HPLC and GC methodologies employing UV and MS detection to new derivatisation-based techniques. The paper also reflects on the significant challenges in developing robust analytical methodology capable of the trace determination of sulfonate esters, the challenges in transferring methodology from R&D to QC labs and on the cost of inappropriate limits for genotox impurities. In so doing, the authors seek to inform the debate that the control of genotoxic impurities should be driven primarily by safety and risk/benefit considerations rather than by state-of-the-art analytical and process chemistry capabilities that drive controls to levels 'as low as practicable' regardless of the risk/safety requirements. PMID:18053672

  8. Caffeic acid phenethyl ester triggers apoptosis through induction of loss of mitochondrial membrane potential in CCRF-CEM cells

    Microsoft Academic Search

    Ç???r Biray Avc?; Cumhur Gündüz; Yusuf Baran; Fahri ?ahin; Sunde Y?lmaz; Zeynep Ozlem Dogan; Güray Saydam

    2011-01-01

    Purpose  CAPE (caffeic acid phenethyl ester) is one of the most valuable and investigated component of propolis which is composed by\\u000a honeybees. In the current study, we aimed at examining apoptotic effects of CAPE on CCRF-CEM leukemic cells and at determining\\u000a the roles of mitochondrial membrane potential (MMP) in cell death.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Trypan blue and XTT methods were used to evaluate the

  9. Synthesis of piperine–amino acid ester conjugates and study of their cytotoxic activities against human cancer cell lines

    Microsoft Academic Search

    V. Rama Subba Rao; G. Suresh; R. Ranga Rao; K. Suresh Babu; G. Chashoo; A. K. Saxena; J. Madhusudana Rao

    \\u000a Abstract  A series of piperine–amino acid ester conjugates (4a–4r) were synthesized under mild conditions and screened for their cytotoxic activities against a panel of human cancer cell\\u000a lines (IMR-32, MCF-7, PC-3, DU-145, Colo-205, and Hep-2). The parent compound piperine lacked significant activity but the\\u000a analogues were effective to in all tested human cancer cell lines. The introduction of d- and l-amino

  10. Vapour pressure and enthalpy of vaporization of di-iso-propyl and di-tert-butyl esters of dicarboxylic acids

    Microsoft Academic Search

    Svetlana V. Portnova; Eugen L. Krasnykh; Sergey P. Verevkin

    2011-01-01

    Molar enthalpies of vaporization of the branched aliphatic alkyl esters of dicarboxylic acids R-CO2-(CH2)n-CO2-R with n=(0–4) with R=iso-C3H7, tert-C4H9 were obtained from the temperature dependence of the vapour pressure measured by the transpiration method. These experimental results were checked for internal consistency and compared with the data available from the literature. A linear correlation of enthalpies of vaporization ?lgHm (298.15K)

  11. Anti-inflammatory effect of caffeic acid methyl ester and its mode of action through the inhibition of prostaglandin E 2, nitric oxide and tumor necrosis factor-? production

    Microsoft Academic Search

    Kyung-Min Shin; In-Tae Kim; Young-Mi Park; Joohun Ha; Jong-Won Choi; Hee-Juhn Park; Yong Sup Lee; Kyung-Tae Lee

    2004-01-01

    The anti-inflammatory effects of caffeic acid (CA), caffeic acid methyl ester (CM) and di-O-acetylcaffeic acid (DAC) were investigated in rats using the carrageenin-induced edema model and the antinociceptive effects of these compounds were also assessed in mice by means of the acetic acid-induced abdominal constriction test and hot plate test. CM (10mg\\/kg, p.o.) showed the most potent anti-inflammatory and antinociceptive

  12. Arsenic in rice (Oryza sativa L.) related to dynamics of arsenic and silicic acid in paddy soils.

    PubMed

    Bogdan, Katja; Schenk, Manfred K

    2008-11-01

    Paddy rice is a global staple food which in some circumstances can contain high levels of the toxic element arsenic (As). In order to elucidate factors influencing As dissolution in the soil solution during paddy rice cultivation, rice (Oryza sativa L. "Selenio") was cultivated to maturity in six paddy soils in the greenhouse in 2005 and 2006. Concentrations of Mn, Fe, As, P, and silicic acid in soil solution and As concentrations in rice straw and polished rice grain were determined. There was a close relationship between Fe and As concentrations in the soil solution, suggesting that the major part of dissolved As originated from reduced iron-(hydr)oxide. However, in addition to the factors causing As dissolution in the soil, other factors influenced the uptake of As by rice. The inhibitory effect of indigenous silicic acid in the soil solution on As uptake was clearly shown. This implied that soils with high plant available Si contents resulted in low plant As contents and that Si application to soils may decrease the As content of rice. PMID:19031876

  13. Kinematic viscosity of biodiesel components (fatty acid alkyl esters) and related compounds at low temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats, has undergone rapid development and acceptance recently. Kinematic viscosity is one of the fuel properties specified in biodiesel standards, with 40 deg C being the temperature at which this property is to be determined ...

  14. ACUTE TOXICITY OF SELECTED SUBSTITUTED PHENOLS, BENZENES AND BENZOIC ACID ESTERS TO FATHEAD MINNOWS 'PIMEPHALES PROMELAS'

    EPA Science Inventory

    Flow-through acute toxicity tests were conducted with 24 organic compounds using fathead minnows Pimephales promelas as test organisms. The tested toxicants consisted of 11 substituted phenols, four substituted benzenes and nine esters. The 96-h LC50 values determined for these c...

  15. Methyl esters (biodiesel) from and fatty acid profile of Gliricidia sepium seed oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing the supply of biodiesel by defining and developing additional feedstocks is important to overcome the still limited amounts available of this alternative fuel. In this connection, the methyl esters of the seed oil of Gliricidia sepium were synthesized and the significant fuel-related prop...

  16. Fuel properties of highly polyunsaturated fatty acid methyl esters: Prediction of fuel properties of algal biodiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats, can be derived from other triacylglycerol-containing feedstocks. Especially algae are being considered for this purpose due to their claimed high production potential. However, there are no comprehensive reports regarding...

  17. On the neutralization of acid rock drainage by carbonate and silicate minerals

    Microsoft Academic Search

    E. J. Sherlock; R. W. Lawrence; R. Poulin

    1995-01-01

    The net result of acid-generating and-neutralizing reactions within mining wastes is termed acid rock drainage (ARD). The oxidation of sulfide minerals is the major contributor to acid generation. Dissolution and alteration of various minerals can contribute to the neutralization of acid. Definitions of alkalinity, acidity, and buffer capacity are reviewed, and a detailed discussion of the dissolution and neutralizing capacity

  18. Simultaneous determination of total fatty acid esters of chloropropanols in edible oils by gas chromatography-mass spectrometry with solid-supported liquid-liquid extraction.

    PubMed

    Liu, Qing; Han, Feng; Xie, Ke; Miao, Hong; Wu, Yongning

    2013-11-01

    This study aimed to establish a novel robust method for the simultaneous determination of total fatty acid esters of 4 chloropropanols including fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD esters), 2-monochloropropane-1,3-diol (2-MCPD esters), 1,3-dichloropropan-2-ol (1,3-DCP esters) and 2,3-dichloropropan-1-ol (2,3-DCP esters) in edible oils. In this method, sodium methylate in methanol was used as the reagent for the ester cleavage reaction of chloropropanols esters. The reaction products were extracted by a sodium sulfate solution, and then purified by solid-supported liquid-liquid extraction (SLE) using diatomaceous earth (Hydromatrix™) as the sorbent. Finally, the extracts were derivatized with heptafluorobutyrylim idazole (HFBI) and analyzed by gas chromatography-mass spectrometry (GC-MS). Quantification was achieved using deuterated chloropropanols as their respective internal standards, including 3-MCPD-d5, 2-MCPD-d5, 1,3-DCP-d5 and 2,3-DCP-d5. A good linear relationship between peak area and concentrations was obtained within the range of 0.025-2.000mgL(-1) with a correlation coefficients not less than 0.999 for all the chloropropanols esters. The limits of detection (LODs) of esters of 3-MCPD, 2-MCPD, 1,3-DCP and 2,3-DCP (calculated as corresponding chloropropanols) were 30, 30, 100 and 30?gkg(-1), respectively. The average recoveries of the 3-MCPD esters and the 4 chloropropanols spiked at 0.1, 0.5 and 2mgkg(-1) into blank oil matrix were typically in a range from 70.7% to 113.3%. The robust method validation data including calibration, LOD/LOQ, accuracy and repeatability and proficiency test results (Z-score: -0.5) of the official Food Analysis Performance Assessment Scheme (FAPAS) indicated that the present quantitative method could be successfully applied to the determination of total chloropropanols esters in various edible oils. PMID:24070627

  19. Toxicities of butoxyethanol ester and propylene glycol butyl ether ester formulations of 2,4-dichlorophenoxy acetic acid (2,4-D) to juvenile salmonids

    Microsoft Academic Search

    B. J. Finlayson; K. M. Verrue

    1985-01-01

    Continuous-flow toxicity tests were conducted to determine acute toxic effects of butoxy-ethanol ester (BOEE) and propylene glycol butyl ether ester (PGBEE) formulations of 2,4-D on juvenile chinook salmon (Oncorhynchus tshawytscha) and steelhead-rainbow trout (Salmo gairdneri). A chronic toxicity test with chinook salmon egg-to-fry was conducted to determine effects of BOEE on survival and growth. The hydrolysis in water of 2,4-D

  20. Importance of Solvation in Understanding the Chiroptical Spectra of Natural Products in Solution Phase: Garcinia Acid Dimethyl Ester

    PubMed Central

    Polavarapu, Prasad L.; Scalmani, Giovanni; Hawkins, Edward K.; Rizzo, Carmelo; Jeirath, Neha; Ibnusaud, Ibrahim; Habel, Deenamma; Nair, Divya Sadasivan; Haleema, Simimole

    2013-01-01

    The optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) spectra of (+)-garcinia acid dimethyl ester have been measured and analyzed by comparison with the corresponding spectra predicted by quantum chemical methods for (2S,3S)-garcinia acid dimethyl ester. For solution-phase calculations the recently developed continuous surface charge polarizable continuum model (PCM) has been used. It is found that gas-phase predictions and PCM predictions at the B3LYP/aug-cc-pVDZ level yield nearly mirror-image ECD spectra in the 190–250 nm region for the same absolute configuration and that gas-phase ECD predictions lead to incorrect absolute configuration. At the CAM-B3LYP/aug-cc-pVDZ level, however, gas-phase predictions and PCM predictions of ECD in the 190–250 nm region are not so different, but PCM predictions provide better agreement with the experimental observations. For carbonyl stretching vibrations, the vibrational band positions predicted at the B3LYP/aug-cc-pVDZ level in gas-phase calculations differ significantly from the corresponding experimentally observed band positions, and this discrepancy has also been corrected by the use of PCM. In addition, the solution-phase VCD predictions provided better agreement (with experimental VCD observations) than gas-phase VCD predictions. These observations underscore the importance of including solvent effects in quantum chemical calculations of chiroptical spectroscopic properties. PMID:21114277

  1. Characterization of an acidic cold-adapted cutinase from Thielavia terrestris and its application in flavor ester synthesis.

    PubMed

    Xu, Haibo; Yan, Qiaojuan; Duan, Xiaojie; Yang, Shaoqing; Jiang, Zhengqiang

    2015-12-01

    An acidic cutinase (TtcutB) from Thielavia terrestris CAU709 was purified to apparent homogeneity with 983Umg(-1) specific activity. The molecular mass of the enzyme was estimated to be 27.3 and 27.9kDa by SDS-PAGE and gel filtration, respectively. A peptide sequence homology search revealed no homologous cutinases from T. terrestris, except for one putative cutinase gene (XP003656017.1), indicating that TtcutB is a novel enzyme. TtcutB exhibited an acidic pH optimum of 4.0, and stability at pH 2.5-10.5. Optimal activity was at 55°C, it was stable up to 65°C, and retained over 30% activity at 0°C. Km values toward p-nitrophenyl (pNP) acetate, pNP-butyrate and pNP-caproate were 8.3, 1.1 and 0.88mM, respectively. The cutinase exhibited strong synthetic activity on flavor ester butyl butyrate under non-aqueous environment, and the highest esterification efficiency of 95% was observed under the optimized reaction conditions. The enzyme's unique biochemical properties suggest great potential in flavor esters-producing industries. PMID:26041215

  2. [Distribution of phthalate acid esters in waters and Potamogeton crispus L. from the mainstream of Haihe River].

    PubMed

    Chi, Jie; Zheng, Yan

    2009-11-01

    Concentrations of phthalate acid esters(PAEs) in waters and aquatic plant, Potamogeton crispus L., were measured from March 29 to May 25, 2008 in the mainstream of Haihe River. The results showed that dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) were detected in all samples of waters and Potamogeton crispus L.. Concentrations of DBP and DEHP in water samples ranged from 0.35-40.68 microg/L (mean 7.32 microg/L) and 3.54-101.2 microg/L (mean 21.72 microg/L), respectively. Concentrations of DBP and DEHP in Potamogeton crispus L. ranged from 0.007-0.242 microg/g (0.078 microg/g) and 0.163-1.286 microg/g (0.457 microg/g), respectively. Concentrations of DBP and DEHP in Potamogeton crispus L. reached the highest value during Potamogeton crispus L. blooming period and were significantly related to concentrations of DBP and DEHP in waters. PCF values of DBP and DEHP by Potamogeton crispus L. were obviously above 1, and the PCFs value reached the maxima during the early growing period and the minima during the period of decay. Concentration and PCF of DBP were both lower than those of DEHP. Potamogeton crispus L. was an important sink of phthalate acid esters, a kind of hydrophobic organic compounds, because of its abundance in Haihe River. PMID:20063741

  3. Heat-shrink tubing as a solid-phase microextraction coating for the enrichment and determination of phthalic acid esters.

    PubMed

    Luo, Xi; He, Chengxia; Zhang, Feifang; Wang, Hailong; Yang, Bingcheng; Liang, Xinmiao

    2014-12-01

    Heat-shrink tubing, which shrinks in one plane only (its diameter) when heated, commonly used for sealing protection in electrical engineering, was found to be able to function as a solid-phase microextraction coating. Its utility was demonstrated for the determination of phthalic acid esters in an aqueous solution combined with high-performance liquid chromatography equipped with a UV absorbance detector. The preparation procedure was rather simple and only ?10 min was needed. The fiber cost is extremely low (?10 cent each). The parameters affecting the extraction were optimized. Heat-shrink tubing fiber exhibited a significant enrichment effect for the three examined phthalic acid esters and up to 931-fold enrichment factor was obtained. The limit of detection was <10 ?g/L for all analytes. The operation repeatability and fiber-to-fiber reproducibility were 1.2-8.3 and 5.4-9.1%, respectively. It was successfully applied for the analysis of bottled drinking water with recoveries ranging from 90.1-100.5%. PMID:25296949

  4. A study of the autoxidation of some unsaturated fatty acid methyl esters using Fourier transform Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Agbenyega, J. K.; Claybourn, M.; Ellis, G.

    Near-infrared Fourier transform Raman and Fourier transform infrared spectroscopy have been used to investigate the chemical changes taking place during the curing reaction of several fatty acid methyl esters, which are used for modelling processes in the autoxidation of alkyd resin coatings. We have studied methyl oleate, methyl linoleate, and methyl linolenate in an attempt to monitor the degree of unsaturation within the fatty acid methyl esters (FAMES) during the complex autoxidation/polymerisation reaction that takes place once the paint system is coated onto a substrate and exposed to the atmosphere. The peaks around 1655 cm -1 have been assigned as follows: to the trans isomer at 1670 cm -1, the cis isomer at 1655 cm -1 and the conjugated structure at 1640 cm -1 [B. Schrader, Raman/Infrared Atlas of Organic Compounds (2nd Edn), VCH, Weinheim (1989); J. K. Abenyega, M. Claybourn and G. Ellis, in preparations]. Raman spectra for the cure of methyl linoleate after 24 h show several interesting features, suggesting the formation of a highly conjugated cyclic structure. Current theories about the mechanism for the autoxidation of methyl linoleate make no mention of this aromatic product.

  5. Highly conductive PEDOT\\/silicate hybrid anode for ITO-free polymer solar cells

    Microsoft Academic Search

    Youn Soo Kim; Seok Bin Oh; Jong Hyeok Park; Mi Suk Cho; Youngkwan Lee

    2010-01-01

    In this work, we prepared ITO-free photovoltaic devices (PVDs) using a transparent poly(3,4-ethylenedioxythiophene):silicate (PEDOT:SiOx) composite anode equipped with low surface resistance and high transparency. A mixture of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C60 butyric acid methyl ester (PCBM) was used as a photoactive layer. PEDOT:SiOx film was fabricated with an inorganic silicate network via the oxidative polymerization of EDOT and in-situ

  6. Non-aqueous gel polymer electrolyte with phosphoric acid ester and its application for quasi solid-state supercapacitors

    NASA Astrophysics Data System (ADS)

    ?atoszy?ska, Anna A.; ?ukowska, Gra?yna Zofia; Rutkowska, Iwona A.; Taberna, Pierre-Louis; Simon, Patrice; Kulesza, Pawel J.; Wieczorek, W?adys?aw

    2015-01-01

    A mechanically-stable non-aqueous proton-conducting gel polymer electrolyte that is based on methacrylate monomers, is considered here for application in solid-state type supercapacitors. An electrochemical cell using activated carbon as active materials and the new gel polymer electrolyte has been characterized at room temperature using cyclic voltammetry, galvanostatic charge-discharge cycle tests as well as impedance spectroscopy. The use of phosphoric acid ester (instead of phosphoric acid) as a proton donor has led to an increase of both the operation voltage window (up to 1.3 V) and the electrolyte ionic conductivity (on the level of an order of magnitude). The resulting double layer capacitance of the microporous activated carbon was found to be as high as 120 F g-1; even more important, the supercapacitor utilizing non-aqueous proton-conducting gel polymer electrolyte is well-behaved in the wide temperature range (namely, from -40 to 80 °C).

  7. Guiding optimal biofuels : a comparative analysis of the biochemical production of ethanol and fatty acid ethyl esters from switchgrass.

    SciTech Connect

    Paap, Scott M.; West, Todd H.; Manley, Dawn Kataoka; Dibble, Dean C.; Simmons, Blake Alexander; Steen, Eric J. [Joint BioEnergy Institute, Emeryville, CA; Beller, Harry R. [Lawrence Berkeley National Laboratory, Berkeley, CA; Keasling, Jay D. [Lawrence Berkeley National Laboratory, Berkeley, CA; Chang, Shiyan [Tsinghua University, Beijing, PR China

    2013-01-01

    In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricity demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.

  8. Lipase-Catalyzed Production of 6-O-cinnamoyl-sorbitol from D-sorbitol and Cinnamic Acid Esters.

    PubMed

    Kim, Jung-Ho; Bhatia, Shashi Kant; Yoo, Dongwon; Seo, Hyung Min; Yi, Da-Hye; Kim, Hyun Joong; Lee, Ju Hee; Choi, Kwon-Young; Kim, Kwang Jin; Lee, Yoo Kyung; Yang, Yung-Hun

    2015-05-01

    To overcome the poor properties of solubility and stability of cinnamic acid, cinnamate derivatives with sugar alcohols were produced using the immobilized Candida antarctica lipase with vinyl cinnamate and D-sorbitol as substrate at 45 °C. Immobilized C. antarctica lipase was found to synthesize 6-O-cinnamoyl-sorbitol and confirmed by HPLC and (1)H-NMR and had a preference for vinyl cinnamate over other esters such as allyl-, ethyl-, and isobutyl cinnamate as co-substrate with D-sorbitol. Contrary to D-sorbitol, vinyl cinnamate, and cinnamic acid, the final product 6-O-cinnamoyl-sorbitol was found to have radical scavenging activity. This would be the first report on the biosynthesis of 6-O-cinnamoyl-sorbitol with immobilized enzyme from C. antarctica. PMID:25809993

  9. Chemical basis of unwettability in Liacaridae (Acari, Oribatida): specific variations of a cuticular acid/ester-based system.

    PubMed

    Brückner, Adrian; Stabentheiner, Edith; Leis, Hans-Jörg; Raspotnig, Günther

    2015-07-01

    Oribatid mites of the family Liacaridae comprise a large number of species with smooth and shiny body surfaces that display extraordinary anti-wetting properties. The principle of liacarid unwettability is not related to micro-structured surfaces as present in many Oribatida ("Lotus effect") but the formation of raincoat-like lipid layers covering the epicuticle. We here conducted a comparative study on the chemistry of cuticular lipid layers in a selection of Liacaridae, including representatives of all major Central European genera, Liacarus, Dorycranosus, Adoristes, and Xenillus. Cuticular lipids of unwettable individuals were removed from mite bodies by hexane extraction, and were analyzed by GC-MS. Basically, two chemically distinguishable systems were found. Type I: cuticular lipids of Liacarus subterraneus, L. coracinus, L. nitens, Dorycranosus curtipilis, and Xenillus tegeocranus contained different carboxylic acids (C8-, C10-, C10:1-, C10:2-acids) and their corresponding di-glycerides in species-specific combinations. Type II: Adoristes ovatus exhibited a system of cuticular lipids composed of esters of pentanoic- and heptanoic acids with C14-, C15-, C16- and C17-alcohols. Interestingly, the chemistry of surface lipids did not reflect the morphology of the cuticle in the species investigated. Smooth and shiny cuticles, though exhibiting a specific pattern of round or slit-like pores, were found in representatives of Liacarus, Dorycranosus (all of which exhibiting cuticular chemistry of type I) and Adoristes (exhibiting cuticular chemistry of type II). Xenillus, possessing a rough, cerotegumental cement layer-covered surface, showed type I-chemistry. The acid-esters systems herein investigated are considered characteristic for the cuticular chemistry of Liacaridae or a lineage of these, and provide first insights into the comparative chemistry of the inner (=lipid) layer of the oribatid cerotegument. PMID:25913033

  10. Efficacy of a methyl ester of 5-aminolevulinic acid in photodynamic therapy for ovarian cancers

    Microsoft Academic Search

    M. Wakui; Yoshihito Yokoyama; H. Wang; T. Shigeto; M. Futagami; H. Mizunuma

    2010-01-01

    Purpose  Photodynamic therapy (PDT) is a new approach to cancer treatment that utilizes photochemical reactions induced by a combination\\u000a of an oncophilic photosensitizing agent and laser light. With an aim to apply PDT for intraperitoneal disseminated foci of\\u000a advanced or recurrent ovarian cancers, the present study was conducted to evaluate the antitumor effect of PDT using a methyl\\u000a ester of 5-aminolevulinic

  11. A continuous process for the conversion of vegetable oils into methyl esters of fatty acids

    Microsoft Academic Search

    H. Noureddini; D. Harkey; V. Medikonduru

    1998-01-01

    A continuous process for the transesterification of triglycerides to methyl esters was investigated in a pilot plant. The\\u000a process was equipped with a motionless and a high-shear mixer. The experimental studies explored variations in the mixing\\u000a intensity, stoichiometry, and catalyst concentration on the overall conversion. The combined as well as individual effect\\u000a of mixers was examined. The developed process resulted

  12. Novel chiral poly(ester-imide)s with different natural amino acids in the main chain as well as in the side chain: synthesis and characterization

    Microsoft Academic Search

    Shadpour Mallakpour; Parvin Asadi

    2010-01-01

    Several novel chiral and potentially biodegradable poly(ester-imide)s (PEI)s bearing natural amino acids in the main chain\\u000a as well as in the side chain were synthesized via direct polyesterification of N,N'-(pyromellitoyl)-bis-(L-tyrosine dimethyl ester) as a biodegradable optically active phenolic diol and synthesized diacids containing different amino\\u000a acids and phthalimide group in the side chain. With the aim of tosyl chloride\\/pyridine\\/N,N-dimethylformamide (DMF)

  13. Absorption and metabolism of the food contaminant 3-chloro-1,2-propanediol (3-MCPD) and its fatty acid esters by human intestinal Caco-2 cells.

    PubMed

    Buhrke, Thorsten; Weisshaar, Rüdiger; Lampen, Alfonso

    2011-10-01

    3-Chloro-1,2-propanediol (3-MCPD) fatty acid esters are formed upon thermal processing of fat-containing foods in the presence of chloride ions. Upon hydrolytic cleavage, these substances could release free 3-MCPD. This compound is toxicologically well characterised and displayed cancerogenic potential in rodent models. Recently, serious contaminations of different food products with 3-MCPD fatty acid esters have been reported. In regard to a risk assessment, the key question is to which degree these 3-MCPD fatty acid esters are hydrolysed in the human gut. Therefore, the aim of the present project was to examine the hydrolysis of 3-MCPD fatty acid esters and the resulting release of free 3-MCPD by using differentiated Caco-2 cells, a cellular in vitro model for the human intestinal barrier. Here, we show that 3-MCPD fatty acid esters at a concentration of 100 ?M were neither absorbed by the cells nor the esters were transported via a Caco-2 monolayer. 3-MCPD-1-monoesters were hydrolysed in the presence of Caco-2 cells. In contrast, a 3-MCPD-1,2-diester used in this study was obviously absorbed and metabolised by the cells. Free 3-MCPD was not absorbed by the cells, but the substance migrated through a Caco-2 monolayer by paracellular diffusion. From these in vitro studies, we conclude that 3-MCPD-1-monoesters are likely to be hydrolysed in the human intestine, thereby increasing the burden with free 3-MCPD. In contrast, intestinal cells seem to have the capacity to metabolise 3-MCPD diesters, thereby detoxifying the 3-MCPD moiety. PMID:21327620

  14. Extraction of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester in the presence of diethylenetriaminepentaacetic acid in aqueous phase

    SciTech Connect

    Kubota, Fukiko; Goto, Masahiro; Nakashio, Fumiyuki [Kyushu Univ., Fukuoka (Japan)

    1993-07-01

    The extraction equilibria of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (commercial name, PC-88A, henceforth abbreviated as HR) dissolved in n-heptane were measured at 303 K. It was found that rare earth metals are extracted with the dimer of the extractant, (HR){sub 2}, as follows. M{sub aq}{sup 3+} + 3(HR){sub 2 org} MR{sub 3} {center_dot} 3HR{sub org} + 3H{sub aq}{sup +} The extraction equilibrium constants of metals were obtained and compared with the extraction equilibrium constants obtained by di(2-ethylhexyl)phosphoric acid (henceforth DZEHPA). Furthermore, the extraction equilibria of rare earth metals with PC-88A in the presence of diethylenetriaminepentaacetic acid (henceforth DTPA) in an aqueous phase were also measured to discuss the effect of DTPA on the extraction of rare earth metals. 13 refs., 8 figs., 2 tabs.

  15. Activation of a carboxy group by dialkyl pyrocarbonates. Synthesis of symmetrical anhydrides and aryl esters of N-protected amino acids using di-tert-butyl pyrocarbonate as condensing reagent

    Microsoft Academic Search

    V. F. Pozdnev; M. Yu. Chernaya

    1984-01-01

    It has been shown that di-tert-butyl pyrocarbonate can be used as a condensing reagent in the production of anhydrides and some aryl esters of carboxylic acids. The synthesis of anhydrides and of phenyl, p-nitrophenyl, ß-naphthyl, and quinolin-8-yl esters of N-protected amino acids is described.

  16. Preparation of highly purified fatty acids via liquid-liquid partition chromatography

    Microsoft Academic Search

    O. S. Privett; E. Christense Nickell

    1963-01-01

    The application of reversed-phase, liquid-liquid partition chromatography to the preparation of highly purified methyl esters\\u000a of fatty acids is described. The parameters of fractionation of methyl esters by this method are demonstrated with model mixtures\\u000a of these compounds. Model mixtures are also used to demonstrate the use of adsorption chromatography on columns of silicic\\u000a acid, impregnated with silver nitrate, in

  17. Ether- and Ester-Bound iso-Diabolic Acid and Other Lipids in Members of Acidobacteria Subdivision 4

    PubMed Central

    Rijpstra, W. Irene C.; Hopmans, Ellen C.; Foesel, Bärbel U.; Wüst, Pia K.; Overmann, Jörg; Tank, Marcus; Bryant, Donald A.; Dunfield, Peter F.; Houghton, Karen; Stott, Matthew B.

    2014-01-01

    Recently, iso-diabolic acid (13,16-dimethyl octacosanedioic acid) has been identified as a major membrane-spanning lipid of subdivisions 1 and 3 of the Acidobacteria, a highly diverse phylum within the Bacteria. This finding pointed to the Acidobacteria as a potential source for the bacterial glycerol dialkyl glycerol tetraethers that occur ubiquitously in peat, soil, lakes, and hot springs. Here, we examined the lipid composition of seven phylogenetically divergent strains of subdivision 4 of the Acidobacteria, a bacterial group that is commonly encountered in soil. Acid hydrolysis of total cell material released iso-diabolic acid derivatives in substantial quantities (11 to 48% of all fatty acids). In contrast to subdivisions 1 and 3 of the Acidobacteria, 6 out of the 7 species of subdivision 4 (excepting “Candidatus Chloracidobacterium thermophilum”) contained iso-diabolic acid ether bound to a glycerol in larger fractional abundance than iso-diabolic acid itself. This is in agreement with the analysis of intact polar lipids (IPLs) by high-performance liquid chromatography-mass spectrometry (HPLC-MS), which showed the dominance of mixed ether-ester glycerides. iso-Diabolic acid-containing IPLs were not identified, because these IPLs are not released with a Bligh-Dyer extraction, as observed before when studying lipid compositions of subdivisions 1 and 3 of the Acidobacteria. The presence of ether bonds in the membrane lipids does not seem to be an adaptation to temperature, because the five mesophilic isolates contained a larger amount of ether lipids than the thermophile “Ca. Chloracidobacterium thermophilum.” Furthermore, experiments with Pyrinomonas methylaliphatogenes did not reveal a major influence of growth temperature over the 50 to 69°C range. PMID:24928878

  18. Gas-liquid chromatographic detection an determination of diacetyl tartaric acid ester of diglyceride in dairy and nondairy coffee cream powders.

    PubMed

    Inoue, T; Iwaida, M; Ito, Y; Tonogai, Y

    1981-03-01

    Diacetyl tartaric acid ester of diglyceride was directly extracted from dairy or nondairy coffee cream powder under acidic conditions with ethyl acetate; then the extract was saponified with methanolic potash. After acidification with HCl, free fatty acid was removed with ether and the reaction mixture was absorbed on an anion exchange column. Tartaric acid was eluted with 2N HCl-acetone (1+1). An aliquot of the trimethylsilyl (TMS) derivative of the eluate was injected into a gas chromatograph with flame ionization detection, and a 1.5% SE-30 column. Recoveries of diacetyl tartaric acid ester of diglyceride at 50, 200, and 2000 ppm were 85.6-99.5%. PMID:7228822

  19. EFFECT OF QUARTZ/MULLITE BLEND CERAMIC ADDITIVE ON IMPROVING RESISTANCE TO ACID OF SODIUM SILICATE-ACTIVATED SLAG CEMENT. CELCIUS BRINE.

    SciTech Connect

    SUGAMA, T.; BROTHERS, L.E.; VAN DE PUTTE, T.R.

    2006-06-01

    We evaluated the usefulness of manufactured quartz/mullite blend (MQMB) ceramic powder in increasing the resistance to acid of sodium silicate-activated slag (SSAS) cementitious material for geothermal wells. A 15-day exposure to 90{sup o} CO{sub 2}-laden H{sub 2}SO{sub 4} revealed that the MQMB had high potential as an acid-resistant additive for SSAS cement. Two factors, the appropriate ratio of slag/MQMB and the autoclave temperature, contributed to better performance of MQMB-modified SSAS cement in abating its acid erosion. The most effective slag/MQMB ratio in minimizing the loss in weight by acid erosion was 70/30 by weight. For autoclave temperature, the loss in weight of 100 C autoclaved cement was a less than 2%, but at 300 C it was even lower. Before exposure to acid, the cement autoclaved at 100 C was essentially amorphous; increasing the temperature to 200 C led to the formation of crystalline analcime in the zeolitic mineral family during reactions between the mullite in MQMB and the Na from sodium silicate. In addition, at 300 C, crystal of calcium silicate hydrate (1) (CSH) was generated in reactions between the quartz in MQMB and the activated slag. These two crystalline phases (CSH and analcime) were responsible for densifying the autoclaved cement, conveying improved compressive strength and minimizing water permeability. The CSH was susceptible to reactions with H{sub 2}SO{sub 4}, forming two corrosion products, bassanite and ionized monosilicic acid. However, the uptake of ionized monosilicic acid by Mg dissociated from the activated slag resulted in the formation of lizardite as magnesium silicate hydrate. On the other hand, the analcime was barely susceptible to acid if at all. Thus, the excellent acid resistance of MQMB-modified SSAS cement was due to the combined phases of lizardite and analcime.

  20. Biosynthesis of D-alanyl-lipoteichoic acid by Lactobacillus casei: interchain transacylation of D-alanyl ester residues

    SciTech Connect

    Childs, W.C. 3d.; Taron, D.J.; Neuhaus, F.C.

    1985-06-01

    Lipoteichoic acid (LTA) from Lactobacillus casei contains poly(glycerophosphate) substituted with D-alanyl ester residues. The distribution of these residues in the in vitro-synthesized polymer is uniform. Esterification of LTA with D-alanine may occur in one of two modes: (i) addition at random or (ii) addition at a defined locus in the poly(glycerophosphate) chain followed by redistribution of the ester residues. A time-dependent transacylation of these residues from D-(/sup 14/C)alanyl-lipophilic LTA to hydrophilic acceptor was observed. The hydrophilic acceptor was characterized as D-alanyl-hydrophilic LTA. This transacylation requires neither ATP nor the D-alanine incorporation system, i.e., the D-alanine activating enzyme and D-alanine:membrane acceptor ligase. No evidence for an enzyme-catalyzed transacylation reaction was observed. The authors propose that this process of transacylation may be responsible for the redistribution of D-alanyl residues after esterification to the poly(glycerophosphate). As a result, it is difficult to distinguish between these proposed modes of addition.

  1. Synthesis and characterization of fatty acid oat ?-glucan ester and its structure-curcumin loading capacity relationship.

    PubMed

    Chen, Fang; Liu, Jia; Ye, Fayin; Zhao, Guohua

    2014-12-17

    An amphiphilic fatty acid oat ?-glucan ester (FAOGE) was first synthesized, and its structure-curcumin loading capacity (CLC) relationship was investigated. The DS of product increased with the addition of acyl imidazole, decreased with Mw of ?-glucan, and did not relate to the acyl chain length. Characterizations by FT-IR and (1)H NMR evidenced the presence of ester groups in FAOGE and confirmed its successful synthesis. The aqueous self-aggregation behavior of FAOGE was revealed by transmission electron microcopy and dynamic light scattering. With the aid of response surface methodology, a quadratic polynomial equation was obtained to quantitatively describe the structure-CLC relationship of FAOGE by using Mw of ?-glucan, acyl chain length, and DS as variables. The CLC increased with Mw of ?-glucan and acyl chain length but maximized at a medium DS. The maximum CLC value was obtained as 4.05 ?g/mg. Hence, FAOGE is a potential candidate in solubilizing and delivering hydrophobic food ingredients. PMID:25429377

  2. Hydroxycinnamoyltransferases lnvolved in the Accumulation of Caffeic Acid Esters in Cametophytes and Sporophytes of Equisetum arvense

    Microsoft Academic Search

    Marianne Hohlfeld; Markus Veit; Dieter Strack

    Four hydroxycinnamoyltransferases from Equisefum arvense L. were studied that catalyze the formation of mono-Ocaffeoyl- meso-tartrate, di-O-caffeoyl-meso-tartrate, 5-Ocaffeoylshikimate (dactylifrate), and 5-Ocaffeoylquinate (chlorogenate). lhe en- zymes were classified as coenzyme A (COA)-ester-dependent acyl- transferases (EC 2.3.1), i.e. hydroxycinnamoyl-CoAmeso-tartrate hydroxycinnamoyltransferase (CTT), hydroxycinnamoyl-CoA:caf- feoyl-meso-tartrate hydroxycinnamoyltransferase (CCT), hydroxy- cinnamoyl-CoAshikimate hydroxycinnamoyltransferase (CST), and hydroxycinnamoyl-CoA:quinate hydroxycinnamoyltransferase. The CTT, CCT, and CST were partially purified and separated from

  3. Enzyme deficiency in cholesteryl ester storage disease

    PubMed Central

    Sloan, Howard R.; Fredrickson, Donald S.

    1972-01-01

    Cholesteryl ester storage disease has been shown to involve severe deficiency of acid cholesteryl ester hydrolase and triglyceride lipase activity in liver, spleen, and lymph node. The cholesteryl ester hydrolase was also deficient in aorta. Tissue storage of both cholesteryl esters and triglycerides is generalized. Both the lipid and enzymatic changes are very similar to those in Wolman's disease. PMID:5032533

  4. Caffeic Acid Phenethyl Ester: Consequences of Its Hydrophobicity in the Oxidative Functions and Cytokine Release by Leukocytes

    PubMed Central

    Paracatu, Luana Chiquetto; Faria, Carolina Maria Quinello Gomes; Rennó, Camila; Palmeira, Patricia; da Fonseca, Luiz Marcos; Ximenes, Valdecir Farias

    2014-01-01

    Numerous anti-inflammatory properties have been attributed to caffeic acid phenethyl ester (CAPE), an active component of propolis. NADPH oxidases are multienzymatic complexes involved in many inflammatory diseases. Here, we studied the importance of the CAPE hydrophobicity on cell-free antioxidant capacity, inhibition of the NADPH oxidase and hypochlorous acid production, and release of TNF-? and IL-10 by activated leukocytes. The comparison was made with the related, but less hydrophobic, caffeic and chlorogenic acids. Cell-free studies such as superoxide anion scavenging assay, triene degradation, and anodic peak potential (Epa) measurements showed that the alterations in the hydrophobicity did not provoke significant changes in the oxidation potential and antiradical potency of the tested compounds. However, only CAPE was able to inhibit the production of superoxide anion by activated leukocytes. The inhibition of the NADPH oxidase resulted in the blockage of production of hypochlorous acid. Similarly, CAPE was the more effective inhibitor of the release of TNF-? and IL-10 by Staphylococcus aureus stimulated cells. In conclusion, the presence of the catechol moiety and the higher hydrophobicity were essential for the biological effects. Considering the involvement of NADPH oxidases in the genesis and progression of inflammatory diseases, CAPE should be considered as a promising anti-inflammatory drug. PMID:25254058

  5. 40 CFR 721.10363 - Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with 4,4? -methylenebis...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...New Uses for Specific Chemical Substances § 721...2-oxiranylmethyl ester, reaction products with 4,4...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...2-oxiranylmethyl ester, reaction products with...

  6. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...New Uses for Specific Chemical Substances § 721...2-hydroxyethyl ester, reaction products with hexakis...generic). (a) Chemical substance and significant...reporting . (1) The chemical substance identified...2-hydroxyethyl ester, reaction products with...

  7. 40 CFR 721.10363 - Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with 4,4? -methylenebis...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...New Uses for Specific Chemical Substances § 721...2-oxiranylmethyl ester, reaction products with 4,4...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...2-oxiranylmethyl ester, reaction products with...

  8. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...New Uses for Specific Chemical Substances § 721...2-hydroxyethyl ester, reaction products with hexakis...generic). (a) Chemical substance and significant...reporting . (1) The chemical substance identified...2-hydroxyethyl ester, reaction products with...

  9. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...New Uses for Specific Chemical Substances § 721...2-hydroxyethyl ester, reaction products with hexakis...generic). (a) Chemical substance and significant...reporting . (1) The chemical substance identified...2-hydroxyethyl ester, reaction products with...

  10. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...New Uses for Specific Chemical Substances § 721...2-hydroxyethyl ester, reaction products with hexakis...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...2-hydroxyethyl ester, reaction products with...

  11. 40 CFR 721.10363 - Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with 4,4? -methylenebis...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...New Uses for Specific Chemical Substances § 721...2-oxiranylmethyl ester, reaction products with 4,4...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...2-oxiranylmethyl ester, reaction products with...

  12. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...New Uses for Specific Chemical Substances § 721...2-hydroxyethyl ester, reaction products with hexakis...generic). (a) Chemical substance and significant...reporting . (1) The chemical substance identified...2-hydroxyethyl ester, reaction products with...

  13. Profiling fatty acids in vegetable oils by reactive pyrolysis-gas chromatography with dimethyl carbonate and titanium silicate.

    PubMed

    Fabbri, Daniele; Baravelli, Valentina; Chiavari, Giuseppe; Prati, Silvia

    2005-12-30

    A novel methodology in on-line pyrolysis-gas chromatography (Py-GC) for the fast analysis of fatty acids in vegetable oils with minimal sample treatment and the use of non-toxic reagents is described. Pyrolysis at 500 degrees C for 10 s of sub-microgram quantity of vegetable oil dissolved in dimethyl carbonate (DMC) and in the presence of nanopowder titanium silicon oxide resulted in the production of fatty acid methyl esters (FAMEs) as unique products. Pyrolysis performed by means of a resistively heated filament pyrolyser interfaced to a GC-MS apparatus enabled the direct analysis of evolved FAMEs. The DMC/Py-GC-MS analysis was tested on soybean, coconut, linseed, walnut and olive oil and the results compared to the classical BF(3)-methanol as reference methodology. The DMC method exhibited a lower precision and was biased towards lower levels of polyunsaturated fatty acids (PUFA) in comparison to the BF(3)-methanol method, but was more advantageous in terms of reduced sample treatment, waste generation and risk factors of employed chemicals. PMID:16216255

  14. Microbial enantioselective ester hydrolysis for the preparation of optically active 4,1-benzoxazepine-3-acetic acid derivatives as squalene synthase inhibitors.

    PubMed

    Tarui, Naoki; Nakahama, Kazuo; Nagano, Yoichi; Izawa, Motowo; Matsumoto, Kiyoharu; Kori, Masakuni; Nagata, Toshiaki; Miki, Takashi; Yukimasa, Hidefumi

    2002-01-01

    Microbial enantioselective ester hydrolysis for the preparation of optically active (3R,5S)-(-)-5-phenyl-4,1-benzoxazepine-3-acetic acid derivatives as potent squalene synthase inhibitors was investigated. Pseudomonas diminuta and Pseudomonas taetrolens hydrolyzed the racemic ethyl ester of the 5-(2-chlorophenyl) analogue to yield the (-)-carboxylic acid with excellent enantiomeric excess (>99% ee). We found that the (-)-enantiomer was an active inhibitor. Bulkiness of the ester moiety did not affect the enantioselectivity but did affect reactivity. The racemic ethyl ester of the 5-(2-methoxyphenyl) analogue, 5-(2,3-dimethoxyphenyl) analogue and 5-(2,4-dimethoxyphenyl) analogue were also hydrolyzed with Pseudomonas taetrolens to afford enantiomerically pure (-)-carboxylic acids in large scale. As another route to (3R,5S)-(-)-7-chloro-5-(2,3-dimethoxyphenyl)-1-neopentyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-acetic acid [(-)-1c], the earlier intermediate (-)-2-amino-5-chloro-alpha-(2,3-dimethoxyphenyl)benzyl alcohol [(-)-12] was successfully obtained by asymmetric hydrolysis of (+/-)-5-chloro-alpha-(2,3-dimethoxyphenyl)-2-pivaloylaminobenzyl acetate with Pseudomonas sp. S-13 with >99% ee in kilogram scale followed by alkaline treatment. The product (-)-12 was converted to (-)-1c without racemization. PMID:11824586

  15. Practical experiences in application of hair fatty acid ethyl esters and ethyl glucuronide for detection of chronic alcohol abuse in forensic cases

    Microsoft Academic Search

    S. Suesse; F. Pragst; T. Mieczkowski; C. M. Selavka; A. Elian; H. Sachs; M. Hastedt; M. Rothe; J. Campbell

    This article presents results from 1872 hair samples, which were analyzed for fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG). The results were evaluated in the context of self-reported drinking behavior, the use of hair cosmetics, the gender of the sample donors and hair sample length. For comparison, CDT and GGT in serum were available in 477 and 454

  16. Effect of hair care and hair cosmetics on the concentrations of fatty acid ethyl esters in hair as markers of chronically elevated alcohol consumption

    Microsoft Academic Search

    Sven Hartwig; Volker Auwärter; Fritz Pragst

    2003-01-01

    Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and

  17. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), ?-butyl-?-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...oxy-1,2-ethanediyl), ?-butyl-?-hydroxy, ester with boric acid (H3 BO3 ) (PMN P-97-636; CAS No. 106008-93-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  18. 40 CFR 721.10216 - 2-Propenoic acid, 3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexyl ester].

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2-propenoic acid, 3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexyl ester (PMN P-09-411; CAS No. 903876-45-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  19. 40 CFR 721.10216 - 2-Propenoic acid, 3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexyl ester].

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2-propenoic acid, 3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexyl ester (PMN P-09-411; CAS No. 903876-45-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...

  20. 40 CFR 721.10466 - 2-Propenoic acid, 2-methyl-, 2-ethyltricyclo[3.3.1.13,7]dec-2-yl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2-propenoic acid, 2-methyl-, 2-ethyltricyclo[3.3.1.13,7]dec-2-yl ester (PMN P-03-563; CAS No. 209982-56-9) is subject to reporting under this section for the significant new uses described in paragraph (a)(2)...