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1

40 CFR 721.3100 - Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine... § 721.3100 Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine...identified generically as oligomeric silicic acid ester compound with a...

2010-07-01

2

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

Code of Federal Regulations, 2012 CFR

...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4 ...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4...

2012-07-01

3

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

Code of Federal Regulations, 2014 CFR

...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4 ...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4...

2014-07-01

4

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

Code of Federal Regulations, 2013 CFR

...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4SiO4...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4 ...acid, ester with 1,2-propanediol, phosphate, anhydride with silicic acid (H4...

2013-07-01

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 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,...

2011-07-01

6

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 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,...

2010-07-01

7

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)

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.

Wohl, Adam Richard

8

Synthesis of pyromellitic acid esters  

NASA Technical Reports Server (NTRS)

The ester acids necessary for studyng the thermochemical properties of pyromellitic acid (PMK)-based peroxides were investigated. Obtaining a tetramethyl ester of a PMK was described. The mechanism of an esterification reaction is discussed, as is the complete esterification of PMK with primary alcohol.

Fedorova, V. A.; Donchak, V. A.; Martynyuk-Lototskaya, A. N.

1985-01-01

9

Synthesis of oxygenated fatty acid esters from santalbic acid ester  

Microsoft Academic Search

The reaction of methyl octadec-trans-11-en-9-ynoate (1) with mercuric sulfate in the presence or absence of sulfuric acid is described. Treatment of 1 with mercuric\\u000a sulfate in absolute methanol yielded methyl 9(10)-oxoocta-dec-trans-11-enoates (Product A). This product, upon treatment withm-chloroperbenzoic acid, afforded methyltrans-11,12-epoxy-9-oxooctadecanoate (4) and methyl 10-oxooctadec-trans-11-enoate (2). Sodium borohydride reduction of A furnished the corresponding hydroxy esters. The treatment of 1

Mohammed Khysar Pasha; Fasih Ahmad

1993-01-01

10

Fumaric acid esters in dermatology.  

PubMed

Fumaric acid esters (FAE) are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF) and three salts of monoethylfumarate (MEF) have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like granuloma annulare, necrobiosis lipoidica and sarcoidosis. In vitro and animal studies suggest some activity in malignant melanoma as well. PMID:23130241

Wollina, Uwe

2011-07-01

11

Fumaric acid esters in dermatology  

PubMed Central

Fumaric acid esters (FAE) are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF) and three salts of monoethylfumarate (MEF) have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like granuloma annulare, necrobiosis lipoidica and sarcoidosis. In vitro and animal studies suggest some activity in malignant melanoma as well. PMID:23130241

Wollina, Uwe

2011-01-01

12

Crystallization Behavior of Fatty Acid Methyl Esters  

Microsoft Academic Search

Biodiesel from most agricultural feedstocks has flow properties that are prone to startup and operability problems during\\u000a cold weather. Biodiesel from soybean oil is generally a mixture of long-chain fatty acid alkyl esters composed of 0.15–0.20\\u000a mass fraction saturated esters (melting point [MP] ? 0 °C) mixed with unsaturated esters (MP < 0 °C). This work investigates\\u000a the crystallization properties of two saturated fatty acid methyl

Robert O. Dunn

2008-01-01

13

75 FR 71556 - Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013, 2014

...FRL-8852-2] Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption AGENCY: Environmental...residues of polyoxyalkylated glycerol fatty acid esters; the mono-, di-, or triglyceride... 18 saturated and unsaturated, fatty acids containing up to 15% water by weight...

2010-11-24

14

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2012-04-11

15

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

Code of Federal Regulations, 2014 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2014-07-01

16

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

Code of Federal Regulations, 2013 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2013-07-01

17

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

Code of Federal Regulations, 2011 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2011-07-01

18

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

Code of Federal Regulations, 2011 CFR

... Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium... Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium...an alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters,...

2011-07-01

19

Esters of valerenic acid as potential prodrugs  

PubMed Central

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

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

2014-01-01

20

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

21

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

Code of Federal Regulations, 2010 CFR

... 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...

2010-07-01

22

Thermoset polymer-layered silicic acid nanocomposites  

NASA Astrophysics Data System (ADS)

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.

Wang, Zhen

23

40 CFR 721.2950 - Carboxylic acid glycidyl esters.  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01 false Carboxylic acid glycidyl esters. 721.2950...721.2950 Protection of Environment ENVIRONMENTAL PROTECTION... § 721.2950 Carboxylic acid glycidyl esters....

2010-07-01

24

40 CFR 721.2950 - Carboxylic acid glycidyl esters.  

Code of Federal Regulations, 2011 CFR

40 Protection of Environment 31 2011-07-01 2011-07-01 false Carboxylic acid glycidyl esters. 721.2950...721.2950 Protection of Environment ENVIRONMENTAL PROTECTION... § 721.2950 Carboxylic acid glycidyl esters....

2011-07-01

25

40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexadecanoic acid, ethenyl ester. 721.4158...721.4158 Protection of Environment ENVIRONMENTAL PROTECTION...721.4158 Hexadecanoic acid, ethenyl ester....

2010-07-01

26

40 CFR 721.3110 - Polycarboxylic acid ester (generic).  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01 false Polycarboxylic acid ester (generic). 721...721.3110 Protection of Environment ENVIRONMENTAL PROTECTION...721.3110 Polycarboxylic acid ester (generic)....

2010-07-01

27

40 CFR 721.3110 - Polycarboxylic acid ester (generic).  

Code of Federal Regulations, 2011 CFR

40 Protection of Environment 31 2011-07-01 2011-07-01 false Polycarboxylic acid ester (generic). 721...721.3110 Protection of Environment ENVIRONMENTAL PROTECTION...721.3110 Polycarboxylic acid ester (generic)....

2011-07-01

28

40 CFR 721.1732 - Nitrobenzoic acid octyl ester.  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01 false Nitrobenzoic acid octyl ester. 721.1732...721.1732 Protection of Environment ENVIRONMENTAL PROTECTION...721.1732 Nitrobenzoic acid octyl ester. (a)...

2010-07-01

29

40 CFR 721.8660 - Propionic acid methyl ester (generic).  

Code of Federal Regulations, 2011 CFR

40 Protection of Environment 31 2011-07-01 2011-07-01 false Propionic acid methyl ester (generic...721.8660 Protection of Environment ENVIRONMENTAL PROTECTION... § 721.8660 Propionic acid methyl ester...

2011-07-01

30

65 FR 10396 - Polyoxyethylated Sorbitol Fatty Acid Esters; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013, 2014

...FRL-6490-8] RIN 2070-AB78 Polyoxyethylated Sorbitol Fatty Acid Esters; Tolerance Exemption AGENCY...for residues of the polymers polyoxyethylated sorbitol fatty acid esters; the sorbitol solution containing up to 15% water is...

2000-02-28

31

Lipid encapsulated docosahexaenoic acid methyl ester  

Technology Transfer Automated Retrieval System (TEKTRAN)

Encapsulation of structurally sensitive compounds within a solid lipid matrix provides a barrier to prooxidant compounds and effectively limits the extent of oxidative degradation. Encapsulated docosahexaenoic acid (DHA) methyl ester was examined as a model compound for functional foods and feeds. S...

32

21 CFR 172.859 - Sucrose fatty acid esters.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

33

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Polyglycerol esters of fatty acids. 172.854 Section 172.854 Food and Drugs...Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol...

2010-04-01

34

21 CFR 172.848 - Lactylic esters of fatty acids.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

35

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

36

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

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

37

Silicate Esters of Paclitaxel and Docetaxel: Synthesis, Hydrophobicity, Hydrolytic Stability, Cytotoxicity, and Prodrug Potential  

PubMed Central

We report here the synthesis and selected properties of various silicate ester derivatives (tetraalkoxysilanes) of the taxanes paclitaxel (PTX) and docetaxel (DTX) [i.e., PTX-OSi(OR)3 and DTX-OSi(OR)3]. Both the hydrophobicity and hydrolytic lability of these silicates can be (independently) controlled by choice of the alkyl group (R). The synthesis, structural characterization, hydrolytic reactivity, and in vitro cytotoxicity against the MDA-MB-231 breast cancer cell line of most of these derivatives are described. We envision that the greater hydrophobicity of these silicates (vis-à-vis PTX or DTX itself) should be advantageous from the perspective of preparation of stable aqueous dispersions of amphiphilic block-copolymer-based nanoparticle formulations. PMID:24564494

2015-01-01

38

Caffeic Acid Phenethyl Ester and Therapeutic Potentials  

PubMed Central

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

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

2014-01-01

39

Flammability Studies of Polymer Layered Silicate Nanocomposites: Polyolefin, Epoxy and Vinyl Ester Resins  

NSDL National Science Digital Library

In the pursuit of improved approaches to fire retarding polymers a wide variety of concerns must be addressed, in addition to the flammability issues. For commodity polymers the low cost of these materials requires that the fire retardant (FR) approach also be of low cost. This limits solutions to the problem primarily to additive type approaches. These additives must be low cost and easily processed with the polymer. In addition, any additive must not excessively degrade the other performance properties of the polymer, and it must not create environmental problems in terms of recycling or disposal of the final product. Polymer layered silicate (PLS) nanocomposites are materials that may fulfil the above requirements for a high performance flame retardant. PLS nanocomposites are hybrid organic polymer-inorganic materials with unique properties when compared with conventional filled polymers [1]. For example, the mechanical properties of a nylon-6 layered-silicate nanocomposite, with a silicate mass fraction of only 5%, show excellent improvement over those for the pure nylon 6. The nanocomposite exhibits a 40% higher tensile strength, 68% greater tensile modulus, 60% higher flexural strength, and a 126% increased flexural modulus. The heat distortion temperature (HDT) is increased from 65 °C to 152 °C [2]. In some cases, increased thermal stability, an important property for improving flammability performance, as well as decreased gas permeability, and increased solvent resistance accompany the improved physical properties. We have reported on the flammability properties of delaminated nylon 6 layered silicate nanocomposites and intercalated polymer layered-silicate nanocomposites prepared from polystyrene (PS) and polypropylene-graft-maleic anhydride (PP-g-MA) [3, 4]. Here, we will briefly review these results and report on our initial studies of the flammability of thermoset PLS nanocomposites: intercalated vinyl ester silicate and intercalated epoxy silicate nanocomposites.

Gilman, J. W.

1999-01-01

40

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

Code of Federal Regulations, 2012 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2012-07-01

41

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

Code of Federal Regulations, 2013 CFR

...description of the neutralization of sulfuric acid esters and sulfonic acids subcategory...SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...description of the neutralization of sulfuric acid esters and sulfonic acids...

2013-07-01

42

Plant-mediated stereoselective biotransformation of phenylglyoxylic acid esters.  

PubMed

Enantioselective reduction of the carbonyl group of three phenylglyoxylic acid esters (methyl, ethyl, and n-propyl esters, 2-4) was conducted using blended plant materials (roots of carrot, beetroot, celeriac and parsley; apple). All used biocatalysts transformed these esters to the corresponding mandelic acid esters with high yield, preferably into the respective R-enantiomer. Butanedione addition improved the enantioselectivity of the reaction. PMID:25265851

Maczka, Wanda Krystyna; Grabarczyk, Ma?gorzata; Wi?ska, Katarzyna; Anio?, Miros?aw

2014-01-01

43

Hydrogenation of 2,4-hexadienoic acid methyl ester  

Microsoft Academic Search

Hydrogenation of 2,4-hexadienoic acid methyl ester on supported metal catalysts (Pd\\/C, Pt\\/C, Rh\\/C and Ru\\/C) has been investigated. Methyl esters of 2-hexenoic and 3-hexenoic acids were formed and further hydrogenated to the methyl ester of hexanoic acid. Palladium was found to be the most active and selective catalyst for this reaction owing to the formation of intermediates.

P. Kluson; P. Kukula; E. Kyslingerova; L. Cerveny

1996-01-01

44

Complexes of Alkyl Esters of Ethylidenediphosphonic Acids with Lanthanide Nitrates  

Microsoft Academic Search

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

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

2008-01-01

45

Biological Oxidation Resistance of L-Ascorbic Acid Cellulose Ester  

Microsoft Academic Search

L-ascorbic acid and sodium carboxymethylcellulose were taken as raw material to synthesize polymer material L-ascorbic acid cellulose ester which had antioxidation effect. Antioxidation effect of o benzylgalloyl microcrystalline cellulose ester was appraised in vitro. The results showed that all the different concentrations L-ascorbic acid cellulose ester significantly improved GSH-Px activity of mice liver. But there was no significant difference among

Liu Ning; Fang Gui-zhen; Chen Shujuan; Lu Zhan-guo; Su Shuang; Liu Tao; Su Rongjun

2010-01-01

46

[New esters of substituted anilinonicotinic and phenylanthranilic acids].  

PubMed

In the search for new non-steroidal antiinflammatory drugs with low ulcerogenic activity, phthalidyl and pivaloyloxymethyl esters of anilinonicotinic and N-phenylanthranilic acids were synthesized. One of them, the 3-phthalidyl ester of 2-([3-(trifluoromethyl)phenyl]amino)-3-pyridinecarboxylic acid, also named talniflumate, showed lower ulcerogenic activity and toxicity and greater antiinflammatory activity than the niflumic acid. PMID:7238853

Los, M; Boned, J E; Piccinali, C

1981-05-01

47

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

DOEpatents

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.

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

1998-01-01

48

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

DOEpatents

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.

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

1998-09-15

49

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2010 CFR

...true Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2010-04-01

50

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2012 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2012-04-01

51

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2014 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2014-04-01

52

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2013 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2013-04-01

53

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2011 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2011-04-01

54

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

55

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

56

78 FR 46283 - Modification of Significant New Uses of Ethaneperoxoic Acid, 1,1-Dimethylpropyl Ester  

Federal Register 2010, 2011, 2012, 2013, 2014

...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,...

2013-07-31

57

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

Code of Federal Regulations, 2010 CFR

...acid, 2-(trimethoxysilyl)-, ethyl ester. 721.7290 Section 721.7290 ...acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical substance and significant...acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No....

2010-07-01

58

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

Code of Federal Regulations, 2010 CFR

...false Ethylene oxide adduct of fatty acid ester with pentaerythritol. 721.3680 Section...3680 Ethylene oxide adduct of fatty acid ester with pentaerythritol. (a) Chemical...generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN...

2010-07-01

59

40 CFR 721.10133 - 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer.  

Code of Federal Regulations, 2010 CFR

...2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer. 721.10133 Section...2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer. (a) Chemical substance...2-propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer (PMN P-07-401;...

2010-07-01

60

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

Code of Federal Regulations, 2010 CFR

... false Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols. 721...6475 Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols. ...generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols...

2010-07-01

61

40 CFR 721.1577 - 1,4-Benzenedicarboxylic acid, bis [4-(ethenyloxy) butyl] ester.  

Code of Federal Regulations, 2010 CFR

...acid, bis [4-(ethenyloxy) butyl] ester. 721.1577 Section 721.1577 ...acid, bis [4-(ethenyloxy) butyl] ester. (a) Chemical substance and significant...acid, bis[4-(ethenyloxy) butyl] ester (PMN P-98-1163; CAS No....

2010-07-01

62

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Fatty acid, ester with styrenated phenol, ethylene oxide...Substances § 721.3700 Fatty acid, ester with styrenated phenol, ethylene oxide...substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

2010-07-01

63

40 CFR 721.2900 - Substituted aminobenzoic acid ester (generic name).  

Code of Federal Regulations, 2010 CFR

... false Substituted aminobenzoic acid ester (generic name). 721.2900 Section...2900 Substituted aminobenzoic acid ester (generic name). (a) Chemical substance...substance substituted aminobenzoic acid ester (PMN P-84-951) is subject to...

2010-07-01

64

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

Code of Federal Regulations, 2010 CFR

... Dialkylaminophenyl imino pyrazole acid ester (generic). 721.987 Section 721... Dialkylaminophenyl imino pyrazole acid ester (generic). (a) Chemical substance...as dialkylaminophenyl imino pyrazole acid ester (PMN P-98-45) is subject to...

2010-07-01

65

40 CFR 721.10142 - Oxabicycloalkane carboxylic acid alkanediyl ester (generic).  

Code of Federal Regulations, 2010 CFR

...Oxabicycloalkane carboxylic acid alkanediyl ester (generic). 721.10142 Section 721...Oxabicycloalkane carboxylic acid alkanediyl ester (generic). (a) Chemical substance...oxabicycloalkane carboxylic acid alkanediyl ester (PMN P-06-199) is subject to...

2010-07-01

66

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

67

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

68

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

69

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

70

Highly efficient tetradentate ruthenium catalyst for ester reduction: especially for hydrogenation of fatty acid esters.  

PubMed

A new tetradentate ruthenium complex has been developed for hydrogenation of esters. The catalyst's structure features a pyridinemethanamino group and three tight chelating five-membered rings. The structure character is believed to be responsible for its high stability and high carbonylation-resistant properties. Thus, this catalyst shows outstanding performance in the catalytic hydrogenation of a variety of esters, especially for fatty acid esters, which may be used in practical applications. New insight on designing hydrogenation catalyst for reducing esters to alcohols has been provided through theoretical calculations. PMID:25582610

Tan, Xuefeng; Wang, Yan; Liu, Yuanhua; Wang, Fangyuan; Shi, Liyang; Lee, Ka-Ho; Lin, Zhenyang; Lv, Hui; Zhang, Xumu

2015-02-01

71

Use of fumaric acid esters in psoriasis.  

PubMed

Fumaric acid esters (FAE) are chemical compounds derived from the unsaturated dicarbonic acid fumaric acid. The usage of FAEs in treatment of psoriasis was introduced in the late 1950's. In the 1980s more standardized oral preparations of FAEs were developed containing dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) as main compounds. In 1994, Fumaderm an enteric-coated tablet containing DMF and calcium, magnesium and zinc salts of MEF was approved for the treatment of psoriasis in Germany and since then has become the most commonly used systemic therapy in this country. Fumaric acids have been proven to be an effective therapy in patients with psoriasis even though the mechanisms of action are not completely understood. About 50-70% of the patients achieve PASI 75 improvement within four months of treatment and without any long-term toxicity, immunosuppressive effects or increased risk of infection or malignancy. Tolerance is limited by gastrointestinal side effects and flushing of the skin. This article reviews pharmacokinetics, uses, contraindications, dosages and side effects of treatment with FAEs. PMID:17456929

Roll, Antonie; Reich, Kristian; Boer, Almut

2007-01-01

72

Equatorial anomeric triflates from mannuronic acid esters.  

PubMed

Activation of mannuronic acid esters leads to a conformational mixture of alpha-anomeric triflates, in which the equatorial triflate ((1)C(4) chair) is formed preferentially. This unexpected intermediate clearly opposes the anomeric effect and is mainly stabilized by the electron-withdrawing carboxylate function at C-5. Because the anomeric center carries a significant positive charge, the (1)C(4) mannopyranosyl chair approximates the favored (3)H(4) half-chair oxacarbenium ion conformation. The excellent beta-selectivity in glycosylations of mannuronates is postulated to originate from the cooperative action of the triflate counterion and the (stereo)electronic effects governing oxacarbenium ion stabilization in the transition state leading to the 1,2-cis product. PMID:19663422

Walvoort, Marthe T C; Lodder, Gerrit; Mazurek, Jaroslaw; Overkleeft, Herman S; Codée, Jeroen D C; van der Marel, Gijsbert A

2009-09-01

73

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

PubMed Central

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

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

2011-01-01

74

21 CFR 178.3450 - Esters of stearic and palmitic acids.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2009-04-01 true Esters of stearic and palmitic acids. 178.3450...Adjuvants and Production Aids § 178.3450 Esters of stearic and palmitic acids. The ester stearyl palmitate or palmityl stearate...

2010-04-01

75

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

Code of Federal Regulations, 2011 CFR

...of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely...conditions: (a) They are manufactured from glycerin, lactic acid, and fatty acids conforming with § 172.860...

2011-04-01

76

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

Code of Federal Regulations, 2014 CFR

...of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely...conditions: (a) They are manufactured from glycerin, lactic acid, and fatty acids conforming with § 172.860...

2014-04-01

77

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

Code of Federal Regulations, 2013 CFR

...of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely...conditions: (a) They are manufactured from glycerin, lactic acid, and fatty acids conforming with § 172.860...

2013-04-01

78

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

Code of Federal Regulations, 2012 CFR

...of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely...conditions: (a) They are manufactured from glycerin, lactic acid, and fatty acids conforming with § 172.860...

2012-04-01

79

Interaction of silicic acid with goethite.  

PubMed

The adsorption of Si on goethite (alpha-FeOOH) has been studied in batch experiments that cover the natural range of Si concentrations as found in the environment. The results have been interpreted and quantified with the charge distribution (CD) and multi-site surface complexation (MUSIC) model in combination with an extended Stern (ES) layer model option. This new double layer approach (ES) accounts for ordering of interfacial water molecules leading to stepwise changes in the location of electrolyte ions near the surface [T. Hiemstra, W.H. Van Riemsdijk, J. Colloid Interface Sci. 301 (2006) 1]. The Si adsorption on goethite peaks at a pH of approximately 9 and decreases at lower and higher pH values. Thermodynamically, the pH-dependency of silicic acid adsorption is related to the value of the proton co-adsorption and can also be linked to the Si charge distribution in the interface as is discussed. Based on published EXAFS data, the adsorption of Si on goethite was modeled as the formation of a bidentate surface complex. The ionic charge distribution (CD) of this complex can be calculated from the geometry of this surface complex, optimized with molecular orbital/density functional theory (MO/DFT), and combined with a correction for water dipole orientation. The resulting CD value has been applied successfully in the description of the adsorption data. The use of a theoretical CD value has the practical advantage of a reduction of the number of adjustable parameters with a factor 2. To describe the adsorption at a high Si loading, formation of a Si polymer, e.g. a tetramer, is proposed. Such a species is only contributing to the overall adsorption at solution concentrations above about 10(-4) M, where super saturation with respect to quartz exists. The adsorbed silica polymer hydrolyzes at high pH. The reactive ligand of the polymer is quite acid (logK approximately 6.5-7.1), which is typically for the triple bond SiO(-1) surface groups of polymerized Si, like amorphous SiO(2)(s), and the triple bond SiO(-1) ligand of the aqueous dimer Si(2)O(OH)(5)O(-1)(aq). The applied model correctly predicts the change of particles charge and the shift in IEP due to proton release upon Si adsorption. PMID:17306821

Hiemstra, Tjisse; Barnett, Mark O; van Riemsdijk, Willem H

2007-06-01

80

HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR PHOSPHOROTHIOIC ACID, TRIMETHYL ESTERS  

EPA Science Inventory

The Health and Environmental Effects Profile for Phosphorothioic Acid, trimethyl esters was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste to support listings of hazardous c...

81

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...

82

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

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

83

Solvent Effects on the Protonation Constants of Some ? Amino Acid Esters in 1,4Dioxane–Water Mixtures  

Microsoft Academic Search

The stoichiometric protonation constants of some ?-amino acid esters (glycine methyl ester, glycine t-butyl ester, l-valine methyl ester, l-valine ethyl ester, l-valine t-butyl ester, l-serine methyl ester, l-serine ethyl ester, l-leucine methyl ester, l-leucine ethyl ester, l-leucine t-butyl ester, l-alanine methyl ester, l-alanine benzyl ester, l-phenylalanine methyl ester, l-phenylalanine ethyl ester, and l-phenylalanine t-butyl ester) in water and 20%, 40%,

Alev Do?an; Nazife Aslan; Esin Canel; Esma K?l?ç

2010-01-01

84

Enzymatic synthesis of wax esters from rapeseed fatty acid methyl esters and a fatty alcohol  

Microsoft Academic Search

Wax esters were transesterified from fatty acid methyl esters of rapeseed and a fatty alcohol (1-hexadecanol, 16:0). The amounts\\u000a of both the substrates were fixed to 0.1 mmol and an immobilized enzyme, Lipozyme, was used as catalyst. The experiment was\\u000a performed following a statistic central composite design with five variables. The enzyme\\/lipid ratio was varied between 0.3–0.9\\u000a of the substrate

Marianne Lilja Hallberg; Daobin Wang; Magnus Härröd

1999-01-01

85

[Test and analysis of acrylic acid ester in industry pipelines].  

PubMed

A new quality and quantity analyzing method for waste gas from chemical industry, especially for acrylic acid ester using air-sampling combined with GC/MS and honeywell air purifier system was firstly advanced in this paper. According to the experiments, the maximum disposal capability of the honeywell air purifier system for acrylic acid ester gas was calculated as about 1 kg x h(-1) and the feasibility and validity of the method was also proved by parallel tests. PMID:22468533

Wu, Bin; Zhang, Hong-Yan; Lu, Lin-Guang

2011-12-01

86

Chromatographic analysis of polyglycerols and their fatty acid esters  

Microsoft Academic Search

Polyglycerols and their fatty acid esters have been analyzed by gas-liquid chromatography (GLC) as trimethylsilyl ether derivatives.\\u000a Linear diglycerols and triglycerols were isolated from commercial polyglycerols by vacuum distillation. Mono- and di-fatty\\u000a acid esters were synthesized in the laboratory. Two isomers of diglycerol have been separated and identified. GLC analysis\\u000a was carried out on columns packed with 3% JXR on

M. R. Sahasrabudhe

1967-01-01

87

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

Code of Federal Regulations, 2010 CFR

...Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol...The food additive lactylated fatty acid esters of glycerol and propylene...specifications: Water insoluble combined lactic acid, 14-18 percent; and acid...

2010-04-01

88

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

Code of Federal Regulations, 2011 CFR

...Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol...The food additive lactylated fatty acid esters of glycerol and propylene...specifications: Water insoluble combined lactic acid, 14-18 percent; and acid...

2011-04-01

89

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

Code of Federal Regulations, 2012 CFR

...Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol...The food additive lactylated fatty acid esters of glycerol and propylene...specifications: Water insoluble combined lactic acid, 14-18 percent; and acid...

2012-04-01

90

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

Code of Federal Regulations, 2014 CFR

...Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol...The food additive lactylated fatty acid esters of glycerol and propylene...specifications: Water insoluble combined lactic acid, 14-18 percent; and acid...

2014-04-01

91

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

Code of Federal Regulations, 2013 CFR

...Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol...The food additive lactylated fatty acid esters of glycerol and propylene...specifications: Water insoluble combined lactic acid, 14-18 percent; and acid...

2013-04-01

92

NMR CHARACTERIZATION OF DIHYDROSTERCULIC ACID AND ITS METHYL ESTER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dihydrosterculic acid (2-octyl cyclopropaneoctanoic acid) and its methyl ester were selected for 1H- and 13C-NMR analysis as compounds representative of cyclopropane fatty acids. The 500 MHz 1H-NMR spectra acquired with CDCl3 as solvent show two individual peaks at -0.30 and 0.60 ppm for the methyl...

93

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

Code of Federal Regulations, 2010 CFR

...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 §...

2010-07-01

94

Synthesis of ? 2 -Isoxazoline fatty acid ester heterocycles  

Microsoft Academic Search

Fatty ester ?-2 heterocycles were prepared in good yields and excellent regioselectivity from 1,3-dipolar cycloaddition reactions between\\u000a methyl 10-undecenoate and nitrile oxides. This methodology provides convenient access to the methyl esters of margaric (4b) and stearic (4c) acids in 63–66% yield that contain the isoxazoline heterocycle between C-10 and C-12. These fatty heterocycle compounds\\u000a are synthesized in a one-pot sequence

James A. Kenar; Sevim Z. Erhan

2001-01-01

95

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2013 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2013-07-01

96

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2014 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2014-07-01

97

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2012 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2012-07-01

98

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2010 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2010-07-01

99

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.  

Code of Federal Regulations, 2011 CFR

... false Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester...identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl...

2011-07-01

100

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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,...

2013-11-27

101

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2013 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2013-04-01

102

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2012 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2012-04-01

103

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2014 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2014-04-01

104

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2011 CFR

...of higher fatty acids. The food additive methyl esters of...prescribed conditions: (a) The food additive is manufactured...of the following straight-chain monocarboxylic acids: Docosahexanoic...associated acid esters. (b) The food additive meets the...

2011-04-01

105

Increased Endobiotic Fatty Acid Methyl Esters Following Exposure to Methanol  

Microsoft Academic Search

Increased Endobiotic Fatty Acid Methyl Esters Following Exposure to Methanol. Kaphalia, B. S., Carr J. B., and Ansari, G. A. S. (1995). Fundam. Appl. Toxicol. 28. 264-273.Human exposure to methanol is likely to increase in the future due to its proposed use as an alternate automobile fuel. Since alcohols are known to esterify the fatty acids in the body and

Bhupendra S. Kaphalia; James B. Carr; G. A. S. Ansari

1995-01-01

106

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...

107

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2011-02-11

108

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

Code of Federal Regulations, 2013 CFR

...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,...

2013-07-01

109

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

Code of Federal Regulations, 2014 CFR

...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,...

2014-07-01

110

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

Code of Federal Regulations, 2012 CFR

...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,...

2012-07-01

111

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2013-01-28

112

40 CFR 721.4097 - 7-Oxabicyclo[4.1.0]heptane-3-carboxylic acid, methyl ester.  

Code of Federal Regulations, 2010 CFR

...heptane-3-carboxylic acid, methyl ester. 721.4097 Section 721.4097 ...heptane-3-carboxylic acid, methyl ester. (a) Chemical substance and significant...heptane-3-carboxylic acid, methyl ester (PMN P-98-101) is subject to...

2010-07-01

113

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

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

2010-11-17

114

Electron driven processes in chlorodifluoroacetic acid methyl ester  

NASA Astrophysics Data System (ADS)

Dissociative electron attachment to gas phase 2-chloro-2,2-difluoroacetic acid methyl ester (CClF2COOCH3) is studied by means of a crossed beams apparatus. Effective cleavage of the C-Cl bond is observed within a broad resonance in the energy range 0-1 eV and visible via the appearance of the light fragment Cl-. In chlorodifluoroacetic acid cleavage of the C-Cl bond was observed not only via the Cl- anion formation but predominantly via expulsion of the neutral chlorine atom leading to the formation of the (M-Cl)- anion. Similar to the previously studied esters CF3COOCH3 and CF3COOC2H5[I. Martin, J. Langer, E. Illenberger, Z. Phys. Chem. 222, 1185 (2008)], we observe reaction due to the cleavage of the ester bond resulting in the formation of the closed shell (M-CH3)- anion.

Kopyra, Janina

2014-07-01

115

Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy  

PubMed Central

Silicon (Si) is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4), as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K), the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel), silica gel (amorphous silicon dioxide), and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4) in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation)-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources. PMID:23298332

2013-01-01

116

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), ...

117

Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogs  

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 slt2' and bck1'), Aspergil...

118

Mobilization of Arsenite by Competitive Interaction with Silicic Acid  

Microsoft Academic Search

Due to the acute toxicity of As, mobilization of even a small fraction of As into surface and ground waters used as a source for drinking water represents a substantial risk to human health. Here we evaluate the mobilization of arsenite (As(III)) from the Fe-(hydr)oxide min- eral goethite (a-FeOOH) through competitive displacement by silicic acid, a naturally occurring and ubiquitous

Todd P. Luxton; Christopher J. Tadanier; Matthew J. Eick

2006-01-01

119

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

120

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

121

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

122

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-08-25

123

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2011-02-16

124

21 CFR 573.640 - Methyl esters of higher fatty acids.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

125

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

Code of Federal Regulations, 2010 CFR

...Boric acid, alkyl and substituted alkyl esters (generic name). 721.1875 Section...Boric acid, alkyl and substituted alkyl esters (generic name). (a) Chemical substance...boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject...

2010-07-01

126

40 CFR 721.8340 - Mono esters from 2- propenoic acid (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Mono esters from 2- propenoic acid (generic...Chemical Substances § 721.8340 Mono esters from 2- propenoic acid (generic...substance identified generically as mono esters from 2-propenoic acid (PMN...

2010-07-01

127

Preparation and surfactant properties of diglycerol esters of fatty acids  

Microsoft Academic Search

Fatty acid mono- and diesters of diglycerol constitute the major portion of commercial polyglycerol esters; hence, their composition\\u000a influences the performance of the latter as emulsifiers. The correlation of structure of the fatty acids in the mono- and\\u000a diesters with surfactant properties is of interest. Linear diglycerol was isolated from polymerized glycerol by acetonation,\\u000a fractional distillation and regeneration. Diglycerol mono-

T. Naveen Kumar; Y. S. R. Sastry; G. Lakshminarayana

1989-01-01

128

Fries rearrangement of aryl esters catalysed by heteropoly acid  

Microsoft Academic Search

Heteropoly acids (HPAs) are active catalysts for the Fries rearrangement of aryl esters (phenyl acetate, phenyl benzoate, and p-tolyl acetate) to yield the acylated phenols and esters together with phenols in homogeneous or heterogeneous liquid-phase systems at 100–170°C. Amongst the HPA catalysts studied are bulk, silica-supported, and sol–gel silica-included H3PW12O40 (PW), as well as bulk Cs+ and Ce3+ salts, Cs2.5H0.5PW12O40

Elena F. Kozhevnikova; Juliette Quartararo; Ivan V. Kozhevnikov

2003-01-01

129

Sulfamic Acid as A Cost-Effective Catalyst for Synthesis of ?-Acyloxyacrylate Esters as Candidate Monomers for Biobased Polymers by Acylation of Pyruvate Esters  

Microsoft Academic Search

Sulfamic acid was used as an efficient catalyst and green alternative for metal-containing acidic material to promote the acylation of pyruvate esters to produce ?-acyloxyacrylate esters, which were candidate monomers for biobased polymers. Polymers from these monomers were useful materials for bio-based plastics, which showed high heat resistance and transparency. A series of ?-acyloxyacrylate esters were converted from pyruvate esters

Zhenxin Zhang; Baochun Ma; Qianqian Zhu; Yong Ding; Changming Wang; Wenfeng Song

2012-01-01

130

4-Dimenthylaminopyridine or Acid-Catalyzed Synthesis of Esters: A Comparison  

ERIC Educational Resources Information Center

A set of highly atom-economic experiments was developed to highlight the differences between acid- and base-catalyzed ester syntheses and to introduce the principles of atom economy. The hydrochloric acid-catalyzed formation of an ester was compared with the 4-dimethylaminopyradine-catalyzed ester synthesis.

van den Berg, Annemieke W. C.; Hanefeld, Ulf

2006-01-01

131

?-Ketoamino acid ester derivatives as promising MAO inhibitors.  

PubMed

?-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

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

2015-01-01

132

Docosahexaenoic acid ethyl esters from Isochrysis galbana  

Microsoft Academic Search

In order to produce docosahexaenoic acid (DHA), a culture of the microalgal strain Isochrysis galbana was implemented. In Erlenmeyer flasks, a natural seawater medium, the Provasoli 1\\/3 medium, was compared to the classical Jones medium for DHA production. The Provasoli 1\\/3 medium stimulated growth (0.44 d?1), but influenced DHA accumulation negatively (0.240 pg cell?1). However, DHA production per liter of

Laurent Poisson; Françoise Ergan

2001-01-01

133

Evaluation of salicylic acid fatty ester prodrugs for UV protection.  

PubMed

The purpose of this study was to investigate the physicochemical properties and in vitro evaluation of fatty ester prodrugs of salicylic acid for ultraviolet (UV) protection. The physicochemical properties such as lipophilicity, chemical stability and enzymatic hydrolysis were investigated with the following fatty ester prodrugs of salicylic acid: octanoyl (C8SA), nonanoyl (C9SA), decanoyl (C10SA), lauroyl (C12SA), myristoyl (C14SA) and palmitoyl oxysalicylate (C16SA). Furthermore, their skin permeation and accumulation were evaluated using a combination of common permeation enhancing techniques such as the use of a lipophilic receptor solution, removal of stratum corneum and delipidization of skin. Their k' values were proportional to the degree of carbon-carbon saturation in the side chain. All these fatty esters were highly stable in 2-propanol, acetonitrile and glycerin, but unstable in methanol and ethanol. They were relatively unstable in liver and skin homogenates. In particular, C16SA was mostly hydrolyzed to its parent compound in hairless mouse liver and skin homogenates, suggesting that it might be converted to salicylic acid after its topical administration. In the skin permeation and accumulation study, C16SA showed the poorest permeation in all skins, suggesting that it could not be permeated in the skin. Furthermore, C14SA and C16SA were less accumulated in delipidized skin compared with normal skin or stripped skin, suggesting that these esters had relatively strong affinities for lipids compared with the other prodrugs in the skin. C16SA showed significantly higher dermal accumulation in all skins compared with its parent salicylic acid. Thus, the palmitoyl oxysalicylate (C16SA) might be a potential candidate for UV protection due to its absence of skin permeation, smaller uptake in the lipid phase and relatively lower skin accumulation. PMID:21244220

Im, Jong Seob; Balakrishnan, Prabagar; Oh, Dong Hoon; Kim, Jung Sun; Jeon, Eun-Mi; Kim, Dae-Duk; Yong, Chul Soon; Choi, Han-Gon

2011-07-01

134

Cu(I)-catalyzed (11)C carboxylation of boronic acid esters: a rapid and convenient entry to (11)C-labeled carboxylic acids, esters, and amides.  

PubMed

Rapid and direct: the carboxylation of boronic acid esters with (11)CO(2) provides [(11)C]carboxylic acids as a convenient entry into [(11)C]esters and [(11)C]amides. This conversion of boronates is tolerant to diverse functional groups (e.g., halo, nitro, or carbonyl). PMID:22308017

Riss, Patrick J; Lu, Shuiyu; Telu, Sanjay; Aigbirhio, Franklin I; Pike, Victor W

2012-03-12

135

Hyaluronic acid butyric esters in cancer therapy.  

PubMed

In this review we focus on a promising novel histone deacetylase (HDAC) inhibitor (HA-But) obtained by the esterification of butyric acid (BA), the smallest HDAC inhibitor, with hyaluronic acid (HA), the main constituent of the extracellular matrix which selectively recognizes a transmembrane receptor (CD44) overexpressed in most primary cancers and associated with tumor progression. In vitro, HA-But has proved to be 10-fold more effective than BA in inhibiting the proliferation of a panel of human cancer cell lines, representative of the most common human cancers, and, similar to BA, to regulate the expression of some cell cycle-related proteins, to induce growth arrest in the G1/G0 phase of the cell cycle and to increase histone acetylation. In vivo, HA-But treatment has demonstrated a marked potency in inhibiting primary tumor growth and lung metastases formation from murine Lewis lung carcinoma (LL3) as well as liver metastases formation from intrasplenic implantation of LL3 or B16-F10 murine melanoma cells. In particular, the effect of s.c. and i.p. treatment with HA-But on liver metastases resulted, respectively, in 87 and 100% metastases-free animals, and in a significant prolongation of the survival time compared to the control groups. The results suggest that the presence of the HA backbone does not interfere with the biological activity of butyric residues and that HA-But could represent a promising cell-targetable antineoplastic agent for the treatment of primary and metastatic tumors. PMID:15746573

Speranza, Annalisa; Pellizzaro, Cinzia; Coradini, Danila

2005-04-01

136

Alkyl-esters of polyacrylic acid as vaccine adjuvants.  

PubMed

Previously, we demonstrated that polyacrylic acid (PAA) augmented significantly the immune response to inactivated Newcastle disease virus (iNDV) in chickens, but that efficacy was insufficient to replace the water-in-mineral oil (W/O) adjuvant applied for boosting primed animals. Attempting to improve its adjuvanticity, PAA with weight-average molecular weight (Mw) of 450 kDa was grafted with alkyl-chains by esterifying the carboxylic groups with octanol and butanol. The butyl-PAA and octyl-PAA esters obtained varied in degree of esterification between 10% and 92%. Adjuvant activity of water-soluble esters for humoral responses to iNDV was examined in chickens primed previously with iNDV without adjuvant. The alkyl-PAA esters exhibited significantly higher responses than unmodified PAA and titres increased with increasing dose of adjuvant. At doses of 2 mg per animal, octyl- and butyl-PAA esters with a substitution rate of 16% (octyl16-PAA and butyl16-PAA, respectively) gave similar titres as W/O. In aged animals primed with live NDV at early age, butyl16-PAA and W/O elicited comparable antibody responses. Butyl16-PAA was also more effective than PAA in stimulating primary immune responses in mice which was accompanied by stronger local reaction determined by monitoring swelling at the site of injection. Reactogenicity of butyl16-PAA was less than of W/O. We concluded that alkyl-PAA esters are strong adjuvants for primary and secondary responses and that they are promising alternatives to the mineral oil-based adjuvants presently used in various veterinary vaccines. PMID:9711806

Hilgers, L A; Nicolas, I; Lejeune, G; Dewil, E; Strebelle, M; Boon, B

1998-10-01

137

Sulfamic Acid as a Cost-Effective Catalyst for Synthesis of ? -acyloxyacrylate Esters as Candidate Monomers for Bio-Based Polymers by Acylation of Pyruvate Esters  

Microsoft Academic Search

Sulfamic acid was used as an efficient catalyst and green alternative for metal-containing acidic material to promote the acylation of pyruvate esters to produce ? -acyloxyacrylate esters which were candidate monomers for bio-based polymers. Polymers from these monomers were useful materials for bio-based plastics which showed high heat resistance and transparency. A series of ? -acyloxyacrylate esters were converted from

Zhenxin Zhang; Baochun Ma; Qianqian Zhu; Yong Ding; Changming Wang; Wenfeng Song

2012-01-01

138

Alternative fuel properties of tall oil fatty acid methyl ester–diesel fuel blends  

Microsoft Academic Search

In this experimental work, tall oil methyl ester–diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester–diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the

Duran Alt?parmak; Ali Keskin; Atilla Koca; Metin Gürü

2007-01-01

139

Silicic acid competes for dimethylarsinic acid (DMA) immobilization by the iron hydroxide plaque mineral goethite.  

PubMed

A surface complexation modeling approach was used to extend the knowledge about processes that affect the availability of dimethylarsinic acid (DMA) in the soil rhizosphere in presence of a strong sorbent, e.g., Fe plaques on rice roots. Published spectroscopic and molecular modeling information suggest for the organoarsenical agent to form bidentate-binuclear inner-sphere surface complexes with Fe hydroxides similar to the inorganic As oxyanions. However, since also the ubiquitous silicic acid oxyanion form the same bidentate binuclear surface complexes, our hypothesis was that it may have an effect on the adsorption of DMA by Fe hydroxides in soil. Our experimental batch equilibrium data show that DMA is strongly adsorbed in the acidic pH range, with a steep adsorption edge in the circumneutral pH region between the DMA acidity constant (pKa=6.3) and the point of zero charge value of the goethite adsorbent (pHpzc=8.6). A 1-pK CD-MUSIC surface complexation model was chosen to fit the experimental adsorption vs. pH data. The same was done for silicic acid batch equilibrium data with our goethite adsorbent. Both model parameters for individual DMA and silicic acid adsorption were then merged into one CD-MUSIC model to predict the binary DMA+Si adsorption behavior. Silicic acid (500 ?M) was thus predicted by the model to strongly compete for DMA with up to 60% mobilization of the latter at a pH6. This model result could be verified subsequently by experimental batch equilibrium data with zero adjustable parameters. The thus quantified antagonistic relation between DMA and silicic acid is discussed as one of factors to explain the increase of the DMA proportion in rice grains as observed upon silica fertilization of rice fields. PMID:25478657

Kersten, Michael; Daus, Birgit

2015-03-01

140

Application of ethyl esters and d3-methyl esters as internal standards for the gas chromatographic quantification of transesterified fatty acid methyl esters in food.  

PubMed

Ethyl esters (FAEE) and trideuterium-labeled methyl esters (d3-FAME) of fatty acids were prepared and investigated regarding their suitability as internal standards (IS) for the determination of fatty acids as methyl esters (FAME). On CP-Sil 88, ethyl esters of odd-numbered fatty acids eluted approximately 0.5 min after the respective FAME, and only coelutions with minor FAME were observed. Depending on the problem, one or even many FAEE can be added as IS for the quantification of FAME by both GC-FID and GC-MS. By contrast, d3-FAME coeluted with FAME on the polar GC column, and the use of the former as IS requires application of GC-MS. In the SIM mode, m/z 77 and 90 are suggested for d3-methyl esters of saturated fatty acids, whereas m/z 88 and 101 are recommended for ethyl esters of saturated fatty acids. These m/z values give either no or very low response for FAME and can thus be used for the analysis of FAME in food by GC-MS in the SIM mode. Fatty acids in sunflower oil and mozzarella cheese were quantified using five saturated FAEE as IS. Gravimetric studies showed that the transesterification procedure could be carried out without of loss of fatty acids. GC-EI/MS full scan analysis was suitable for the quantitative determination of all unsaturated fatty acids in both food samples, whereas GC-EI/MS in the SIM mode was particularly valuable for quantifying minor fatty acids. The novel GC-EI/MS/SIM method using fatty acid ethyl esters as internal standards can be used to quantify individual fatty acids only, that is, without determination of all fatty acids (the common 100% method), although this is present. This was demonstrated by the exclusive quantification of selected fatty acids including methyl-branched fatty acids, erucic acid (18:1n-9trans), and polyunsaturated fatty acids in cod liver oil and goat's milk fat. PMID:16637674

Thurnhofer, Saskia; Vetter, Walter

2006-05-01

141

Evaluation of Thermal Transitions in Some Cholesteryl Esters of Saturated Aliphatic Acids  

Microsoft Academic Search

The heats and temperatures of transition for fourteen cholesteryl esters of saturated aliphatic acids have been evaluated using a Perkin-Elmer Differential Scanning Calorimeter, DSC-IB. Most esters tested were first recrystallized from n-pentyl alchol. Among several recrystallization solvents tested, n-pentyl alchol was most effective in removing impurities and eliminating ester transitions caused by these impurities. Ester purity was determined by a

G. Jerry Davis; Roger S. Porter; Edward M. Barrall II

1970-01-01

142

Effect of formic acid and benzoic acid esters on grass preservation  

E-print Network

alternatives for benzoic acid and propionic acid was the high prices of these components. The esters of benzoic five times. The silages were analyzed by titration method (1989, Moisio and Heikonen, Anim Feed Sci was significantly lower in all test silages compared to AIV 2 and NO silages. The results suggest that in making

Paris-Sud XI, Université de

143

21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.  

Code of Federal Regulations, 2010 CFR

...refined (Gersthofen process) montan wax acids. 178.3770 Section 178.3770 Food...refined (Gersthofen process) montan wax acids. Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids identified in this section may be...

2010-04-01

144

40 CFR 721.10440 - Diphosphoric acid, polymers with ethoxylated reduced Me esters of reduced polymd. oxidized...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Diphosphoric acid, polymers with ethoxylated reduced Me esters of... § 721.10440 Diphosphoric acid, polymers with ethoxylated reduced Me esters of...substance identified as diphosphoric acid, polymers with ethoxylated reduced Me...

2013-07-01

145

40 CFR 721.10440 - Diphosphoric acid, polymers with ethoxylated reduced Me esters of reduced polymd. oxidized...  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Diphosphoric acid, polymers with ethoxylated reduced Me esters of... § 721.10440 Diphosphoric acid, polymers with ethoxylated reduced Me esters of...substance identified as diphosphoric acid, polymers with ethoxylated reduced Me...

2014-07-01

146

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

PubMed Central

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

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

2006-01-01

147

Presystemic metabolism and intestinal absorption of antipsoriatic fumaric acid esters.  

PubMed

Psoriasis is a chronic inflammatory skin disease. Its treatment is based on the inhibition of proliferation of epidermal cells and interference in the inflammatory process. A new systemic antipsoriasis drug, which consists of dimethylfumarate and ethylhydrogenfumarate in the form of their calcium, magnesium and zinc salts has been introduced in Europe with successful results. In the present study, a homologous series of mono- and diesters of fumaric acid has been studied with respect to the sites and kinetics of presystemic ester degradation using pancreas extract, intestinal perfusate, intestinal homogenate and liver S9 fraction. In addition, intestinal permeability has been determined using isolated intestinal mucosa as well as Caco-2 cell monolayers, in order to obtain estimates of the fraction of the dose absorbed for these compounds. Relationships between the physicochemical properties of the fumaric acid esters and their biological responses were investigated. The uncharged diester dimethylfumarate displayed a high presystemic metabolic lability in all metabolism models. It also showed the highest permeability in the Caco-2 cell model. However, in permeation experiments with intestinal mucosa in Ussing-type chambers, no undegraded DMF was found on the receiver side, indicating complete metabolism in the intestinal tissue. The intestinal permeability of the monoesters methyl hydrogen fumarate, ethyl hydrogen fumarate, n-propylhydrogen fumarate and n-pentyl hydrogen fumarate increased with an increase in their lipophilicity, however, their presystemic metabolism rates likewise increased with increasing ester chain length. It is concluded that for fumarates, an increase in intestinal permeability of the more lipophilic derivatives is counterbalanced by an increase in first-pass extraction. PMID:12973823

Werdenberg, D; Joshi, R; Wolffram, S; Merkle, H P; Langguth, P

2003-09-01

148

Development and validation of non-aqueous capillary electrophoresis methods to analyze boronic esters and acids.  

PubMed

Boronic esters and acids are potential intermediates in the manufacture of many active pharmaceutical ingredients (API). Accurate quantitation of the intermediate is necessary to assure the stoichiometry of the reaction. The analysis of these compounds is challenging due to their labile nature. For example, the boronic ester can hydrolyze to the acid during storage, when exposed to moisture in the air, during sample preparation and analysis, and thus give erroneous ester results. Traditional analytical techniques like gas chromatography (GC), normal phase chromatography (NPLC), hydrophilic interaction chromatography (HILIC), and reversed phase liquid chromatography (RPLC) have been utilized but with noted limitations such as poor peak shape, variation in retention times, and evidence of hydrolysis. All of these limitations impact accurate quantitation needed for selected situations. For the proprietary boronic ester evaluated here, these traditional techniques were insufficient for the accurate determination of assay and residual boronic acid. Non-aqueous capillary electrophoresis (NACE) is an accurate quantitative technique that can be used to analyze boronic esters and their corresponding acids without the limitations noted for traditional analytical techniques. The present study describes the development of methodology for the determination of the potency of a proprietary boronic ester as well as methodology for the determination of residual boronic acid in the ester. In addition, nine model boronic ester and acid pairs with a range in polarity, based on the electronic properties of the attached side group, were tested to evaluate and demonstrate the general applicability of these conditions. Under the conditions used for potency, all ten pairs had a resolution between the boronic ester and acid of greater than 1.5, acceptable peak shape for the boronic ester (tailing factor of less than 2.0), and a run time of less than 3 min. In addition, this work describes the development of methodology to determine residual levels of boronic acids in the corresponding boronic ester. Using the ten boronic ester and acid pairs, eight of the ten pairs were shown to have acceptable sensitivity (S/N of 10 or better at 0.5%) and spike recoveries (within the range of 80-120%). The potential for hydrolysis during analysis was also addressed by using a subset of the ten boronic ester and acid pairs and spiking water into the diluent. There was no observed conversion of the ester to the acid. The lack of hydrolysis during analysis and the high success in separating and validating these methods for the boronic ester and acid pairs supports the utility of NACE as a technique for the analysis of boronic esters and acids. PMID:22386209

Forst, Mindy B; Warner, Anne M

2012-05-01

149

Synthesis, Evaluation of Anticancer Activity and QSAR Study of Heterocyclic Esters of Caffeic Acid  

PubMed Central

Caffeic acid phenethyl ester (CAPE) suppresses the growth of transformed cells such as human breast cancer cells, hepatocarcinoma , myeloid leukemia, colorectal cancer cells, fibrosarcoma, glioma and melanoma. A group of heterocyclic esters of caffeic acid was synthesized using Mitsunobu reaction and the esters were subjected to further structural modification by electrooxidation of the catechol ring of caffeic acid esters in the presence of sodium benzenesulfinate and sodium toluensulfinate as nucleophiles. Both heterocyclic esters of caffeic acid and their arylsulfonyl derivatives were evaluated for their cytotoxic activity against HeLa, SK-OV-3, and HT-29 cancer cell lines. HeLa cells showed the highest sensitivity to the compounds and heterocyclic esters with no substituent on catechol ring showed better activity compared to their substituted counterparts. QSAR studies reemphasized the importance of molecular shape of the compounds for their cytotoxic activity. PMID:24523750

Hajmohamad Ebrahim Ketabforoosh, Shima; Amini, Mohsen; Vosooghi, Mohsen; Shafiee, Abbas; Azizi, Ebrahim; Kobarfard, Farzad

2013-01-01

150

Modification of spleen phospholipid fatty acid composition by dietary fish oil and by n-3 fatty acid ethyl esters.  

PubMed

We have compared the effects of diets containing purified ethyl esters of either eicosapentaenoic acid, docosahexaenoic acid, or a mixture of both of these compounds, with diets containing either purified fish oil or beef tallow on spleen phospholipid fatty acid composition. Autoimmune mice, the (NZB x NZW)F1 strain, were fed with experimental diets for 14 weeks, after which spleen phospholipids were extracted and separated into classes by HPLC, and the alkenylacyl, alkylacyl, and diacyl subclasses of glycerylphosphatidylethanolamine and glycerylphosphatidylcholine were resolved as their benzoyl esters by HPLC. Fatty acids were analyzed by capillary gas-liquid chromatography of their methyl esters. Each of the marine lipid diets suppressed n-6 fatty acids and elevated n-3 fatty acids in all phospholipids. The eicosapentaenoic acid ethyl ester diets led to high levels of eicosapentaenoic acid and docosapentaenoic acid (C22:5n-3), but little or no increase in docosahexaenoic acid. The docosahexaenoic acid ethyl ester diets elevated docosahexaenoic acid, docosapentaenoic acid, and eicosapentaenoic acid in all phospholipids, indicating that extensive retroconversion of 22 carbon n-3 fatty acids had occurred. These results document changes in the fatty acid composition of mammalian phospholipids that are induced by dietary fish oil triglycerides and by dietary long chain n-3 fatty acid ethyl esters. PMID:8409773

Robinson, D R; Xu, L L; Knoell, C T; Tateno, S; Olesiak, W

1993-08-01

151

Complexes of polyadenylic acid and the methyl esters of amino acids  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

152

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

Microsoft Academic Search

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,

WILLIAM R. MORRISON; LLOYD M. SMITH

153

FATTY ACID ETHYL ESTERS: QUANTITATIVE BIOMARKERS FOR MATERNAL ALCOHOL CONSUMPTION  

PubMed Central

Objective To develop a laboratory marker to identify newborns exposed to alcohol. Study design Meconium was collected from 30 infants from Jordan who were unexposed and from 248 Cleveland study infants of varying exposure status. Retrospective maternal alcohol histories were obtained. Fatty acid ethyl esters (FAEEs) were quantified with gas chromatography/flame ionization and compared between abstainers and non-abstainers to identify FAEEs of interest. The area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values were calculated by using definitions of drinking obtained from a graphical representation. Results Six of 7 FAEEs were significantly different between the non-abstainers and at least 1 of 2 of the abstaining groups. FAEEs best predicted drinks per drinking day, and ethyl linoleate had the greatest area under the curve (76%), with a sensitivity rate of 88%, a specificity rate of 64%, a positive predictive value of 9%, and a negative predictive value of 99%. No combination of FAEEs was better than a single ester for identifying drinkers. Conclusion Ethyl linoleate in meconium is a useful biological marker for identifying infants not exposed in utero to high levels of alcohol in a high-risk, substance-abusing, clinic-based sample. PMID:15973326

Bearer, Cynthia F.; Santiago, Luis Manuel; O’Riordan, Mary Ann; Buck, Kevin; Lee, Siemay C.; Singer, Lynn T.

2014-01-01

154

Enzymatic production of bioactive docosahexaenoic acid phenolic ester.  

PubMed

Docosahexaenoic acid (DHA) is increasingly considered for its health benefits. However, its use as functional food ingredient is still limited by its instability. In this work, we developed an efficient and solvent-free bioprocess for the synthesis of a phenolic ester of DHA. A fed-batch process catalyzed by Candida antarctica lipase B was optimised, leading to the production of 440 g/L vanillyl ester (DHA-VE). Structural characterisation of the purified product indicated acylation of the primary OH group of vanillyl alcohol. DHA-VE exhibited a high radical scavenging activity in acellular systems. In vivo experiments showed increased DHA levels in erythrocytes and brain tissues of mice fed DHA-VE-supplemented diet. Moreover, in vitro neuroprotective properties of DHA-VE were demonstrated in rat primary neurons exposed to amyloid-? oligomers. In conclusion, DHA-VE synergized the main beneficial effects of two common natural biomolecules and therefore appears a promising functional ingredient for food applications. PMID:25308686

Roby, Mohamed H; Allouche, Ahmad; Dahdou, Layal; De Castro, Vanessa C; da Silva, Paulo H Alves; Targino, Brenda N; Huguet, Marion; Paris, Cédric; Chrétien, Françoise; Guéant, Rosa-Maria; Desobry, Stéphane; Oster, Thierry; Humeau, Catherine

2015-03-15

155

Unnatural Amino Acids. 2. Simple Method of Obtaining Esters of Aziridine2-carboxylic Acids by a Transesterification Reaction  

Microsoft Academic Search

A series of N-unsubstituted esters of aziridine-2-carboxylic acid has been obtained by transesterification in basic medium using primary, secondary, and tertiary alcohols. Methods of transesterification using various bases (K2CO3, ROLi, t-BuOK) have been compared. Transesterification with lithium alcoholates also affords the possibility of obtaining esters of N-substituted aziridine-2-carboxylic acids. Transesterification of chiral esters proceeds with retention of the configuration of

B. Shtrumfs; D. Chernyak; I. Kums; I. Kalvins; P. Trapencieris

2004-01-01

156

Characteristics of Palm Fatty Acid Ester (PFAE), a New Vegetable Based Insulating Oil for Transformers  

NASA Astrophysics Data System (ADS)

We have developed new vegetable based insulating oil for transformers called PFAE (Palm Fatty Acid Ester). PFAE has 0.6 times less viscosity and 1.3 times higher dielectric constant compared to mineral oil. The oxidative stability, biodegradability and acute toxicity to fish of PFAE has also been determined to be superior to mineral oil. In this paper, in order to optimize the characteristics of fatty acid esters originating from palm oil, several kinds of fatty acid alkyl esters were first synthesized in the laboratory by the molecular design technique and the transesterification from fatty acid methyl esters and alkyl alcohols. Next the electro-chemical characteristics of the fatty acid alkyl esters as insulating oil were analyzed.

Suzuki, Takashi; Kanoh, Takaaki; Koide, Hidenobu; Hikosaka, Tomoyuki

157

40 CFR 721.10165 - Carbonotrithioic acid, bis(phenylmethyl) ester.  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01 false Carbonotrithioic acid, bis(phenylmethyl) ester...721.10165 Protection of Environment ENVIRONMENTAL PROTECTION...10165 Carbonotrithioic acid, bis(phenylmethyl)...

2010-07-01

158

Resolution of Carboxylic Acids Using Copper (I)-Promoted Removal of Propargylic Esters Under Neutral Conditions  

PubMed Central

A method for the optical resolution of carboxylic acids is described. Condensation of racemic carboxylic acids with chiral terminal propargyl alcohols gave separable diastereomeric esters. Chromatographic separation followed by heating the individual diastereomers in methanol with catalytic copper (I) halide regenerated the carboxylic acids in good yields and in enantiomeric ratios of ?94%. This method is particularly useful for the resolution of carboxylic acids that are incompatible with conventional ester hydrolysis. PMID:21491889

Ghosh, Partha

2013-01-01

159

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

NASA Technical Reports Server (NTRS)

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.

Weber, Arthur L.; Hsu, Victor

1990-01-01

160

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...

161

[Development of the determination methods of fatty acid esters of chloropropanediols in fat-rich foods].  

PubMed

Fatty acid esters of chloropropanediols are a kinds of newly emerged food contaminants, especially 3-monochloropropane-1,2-diol (3-MCPD) esters that have been detected in many foodstuffs such as infant formula and edible oils at relatively high levels. Based on the Tolerable Dose Intake (TDI) of 3-MCPD, the intake of 3-MCPD from 3-MCPD esters may cause the health risk to human beings. The researches for the analysis of 3-MCPD esters have been carried out in some institutes abroad, but there were only a few in China. This paper reviews the methods for the determination of 3-MCPD esters in fat-rich foods, including the extraction, hydrolysis, the derivatization of 3-MCPD esters, the total amount of 3-MCPD esters and the amounts of monoesters and diesters of 3-MCPD. PMID:23697171

Yan, Xiaobo; Wu, Shaoming; Li, Nan; Lü, Huadong; Fu, Wusheng

2013-02-01

162

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

Code of Federal Regulations, 2014 CFR

...Section 417.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...

2014-07-01

163

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

Code of Federal Regulations, 2011 CFR

...Section 417.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory...

2011-07-01

164

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...  

Code of Federal Regulations, 2013 CFR

...2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...2-propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl...

2013-07-01

165

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...  

Code of Federal Regulations, 2014 CFR

...2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...2-propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl...

2014-07-01

166

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

...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...

2010-01-27

167

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-04-21

168

Lewis Acid Promoted Ruthenium(II)-Catalyzed Etherifications by Selective Hydrogenation of Carboxylic Acids/Esters.  

PubMed

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

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

2015-04-20

169

Fractionation of fats, oils, and waxes on thin layers of silicic acid  

Microsoft Academic Search

Summary  Adsorption chromatography on thin layers of silicic acid or alumina provides a new and highly efficient analytical tool for\\u000a the rapid separation of lipids according to classes of compounds.

Helmut K. Mangold; Donald C. Malins

1960-01-01

170

Autoxidation of Conjugated Linoleic Acid Methyl Ester in the Presence of ?-Tocopherol: The Hydroperoxide Pathway  

Microsoft Academic Search

Autoxidation of conjugated linoleic acid (CLA) methyl ester follows at least partly Farmer’s hydroperoxide theory. A mechanism\\u000a for this hydroperoxide pathway has been proposed based on autoxidation of 9-cis,11-trans-CLA methyl ester. This investigation aims at confirming and further clarifying the mechanism by analyzing the hydroperoxides\\u000a produced from 10-trans,12-cis-CLA methyl ester and by theoretical calculations. Five methyl hydroxyoctadecadienoates were isolated by

Taina I. Pajunen; Mikael P. Johansson; Tapio Hase; Anu Hopia

2008-01-01

171

Gas chromatography-mass spectrometry of methyl esters of unsaturated oxygenated fatty acids  

Microsoft Academic Search

Silylation of hydroxyl groups in methyl esters of unsaturated hydroxy acids provides compounds that give mass spectra which\\u000a can be readily interpreted, whereas spectra of underivatized esters are extremely difficult to evaluate. The relationship\\u000a of the double bond(s) to the trimethylsiloxy (TMS) group results in specific mass spectral patterns. In esters that have the\\u000a TMS group separated from the double

R. Kleiman; G. F. Spencer

1973-01-01

172

Fundamental Study on Temperature Dependence of Deposition Rate of Silicic Acid - 13270  

SciTech Connect

The dynamic behavior of the silicic acid is one of the key factors to estimate the condition of the repository system after the backfill. This study experimentally examined the temperature dependence of dynamic behavior of supersaturated silicic acid in the co-presence of solid phase, considering Na ions around the repository, and evaluated the deposition rate constant, k, of silicic acid by using the first-order reaction equation considering the specific surface area. The values of k were in the range of 1.0x10{sup -11} to 1.0x10{sup -9} m/s in the temperature range of 288 K to 323 K. The deposition rate became larger with increments of temperature under the Na ion free condition. Besides, in the case of Na ions 0.6 M, colloidal silicic acid decreased dramatically at a certain time. This means that the diameter of the colloidal silicic acid became larger than the pore size of filter (0.45 ?m) due to bridging of colloidal silicic acid. Furthermore, this study estimated the range of altering area and the aperture of flow-path in various value of k corresponding to temperature by using advection-dispersion model. The concentration in the flow-path became lower with increments of temperature, and when the value of k is larger than 1.0x10{sup -11} m/s, the deposition range of supersaturated silicic acid was estimated to be less than 20 m around the repository. In addition, the deposition of supersaturated silicic acid led the decrement of flow-path aperture, which was remarkable under the condition of relatively high temperature. Such a clogging in flow paths is expected as a retardation effect of radionuclides. (authors)

Shinmura, Hayata; Niibori, Yuichi; Mimura, Hitoshi [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, 6-6-01-2 Aobayama, Aoba-ku, Sendai 980-8579 (Japan)] [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, 6-6-01-2 Aobayama, Aoba-ku, Sendai 980-8579 (Japan)

2013-07-01

173

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

Microsoft Academic Search

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

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

2004-01-01

174

Applications of Propargyl Esters of Amino Acids in Solution-Phase Peptide Synthesis  

PubMed Central

Propargyl esters are employed as effective protecting groups for the carboxyl group during solution-phase peptide synthesis. The propargyl ester groups can be introduced onto free amino acids by treating them with propargyl alcohol saturated with HCl. The reaction between propargyl groups and tetrathiomolybdate is exploited to deblock the propargyl esters. The removal of the propargyl group with the neutral reagent tetrathiomolybdate ensures that most of the other protecting groups used in peptide synthesis are untouched. Both acid labile and base labile protecting groups can be removed in the presence of a propargyl ester. Amino acids protected as propargyl esters are employed to synthesize di- to tetrapeptides in solution-phase demonstrating the possible synthetic utilities of the methodology. The methodology described here could be a valuable addition to currently available strategies for peptide synthesis. PMID:21760822

Ramapanicker, Ramesh; Gupta, Rohit; Megha, Rajendran; Chandrasekaran, Srinivasan

2011-01-01

175

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

E-print Network

The effect of benzoic acid or its ethyl ester on rumen fermentation parameters J Nousiainen Valio be used as mould and yeast inhibitors in silage additives to improve the aerobic stability of silage response of BA or its ethyl ester (EB) on the rumen fermentation parameters in the continuous culture

Paris-Sud XI, Université de

176

Fatty acid sulphoalkyl amides and esters as cosmetic surfactants.  

PubMed

Synopsis A review is given of the manufacture, properties and applications of the anionic surfactants commonly known as taurates and isethionates (fatty acid sulphoalkyl amides and esters, respectively). Originally developed in the 1930s for textile processing, these surfactants are used increasingly in the cosmetic field, particularly those derived from coconut fatty acid. Both types are produced from sodium isethionate, HO degrees C(2)H(4)SO(3)Na. The acyl isethionate, R degrees COO degrees C(2)H(4)SO(3)Na, is obtained by reaction with a fatty acid ('direct process'). or fatty acid chloride ('indirect process'). The direct process is cheaper but requires extreme conditions which can lead to discoloration of the product and a loss of shorter chain fatty acid components. The N-methyl-N-acyltaurate, R degrees CON(R(1))C(2)H(4)SO(3)Na, is obtained by Schotten-Baumann reaction of a fatty acid chloride with N-methyltaurine, which is derived from sodium isethionate via methylamine. Taurates and isethionates retain the benefits of the soaps to which they are structurally similar, but chemical modifications have eliminated many undesirable features. Thus they combine good detergency and wetting with high foaming, and maintain their performance in hard or salt water. Taurates are stable to hydrolysis over the whole pH range. Isethionates are prone to hydrolysis at high (>8) or low (<5) pH, but this does not normally present a problem in cosmetic formulations. Above all, these surfactants are characterized by their extreme mildness to skin. Syndet and syndet/soap bars based on isethionate can be formulated at neutral pH ('Dove type'bars) instead of the alkaline pH of soap, and have been shown in various studies to be milder than soap and better tolerated by the young, the old and those with sensitive skins. Similarly, isethionates have been shown to be less irritating than other anionic or amphoteric surfactants used in cosmetics. The difference has been related to the negligible effect of isethionate on the water-binding capacity of stratum corneum. Other cosmetic applications besides toilet bars include shampoos (excellent cleaning, mild to scalp, some hair conditioning effects), liquid soaps (mild for all-over body use), bubble baths (copious stable foam, efficient lime soap dispersal, low irritancy), skin creams and lotions (emulsification, alleviation of 'dry skin'), baby care products (ultra-mild cleansing bars and milks, impregnated baby wipes) and oral products (foaming agents with low toxicity for toothpastes and mouthwashes). PMID:19467117

Petter, P J

1984-10-01

177

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...

178

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

PubMed Central

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

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

2010-01-01

179

[Phthalic acid esters (PAEs) pollution in farmland soils: a review].  

PubMed

The environmental pollution and food safety problems caused by phthalic acid esters (PAEs) have been attracted 'extensive attention around the world. As a large PAEs producer and consumer, China is facing severe PAEs environmental pollution problems. This paper reviewed the present pollution status of six PAEs classified by the U.S. Environmental Protection Agency as the priority pollutants in China farmland soils, analyzed the sources of these six PAEs in this country, and discussed the absorption and accumulation characteristics of the PAEs in different crops as well as the bio-toxic effects of PAEs pollutants. The PAEs concentrations in China farmland soils are significantly higher those in the farmland soils of the United States and European countries. The main sources of PAEs in China farmland soils are atmospheric deposition, agricultural films, sewage sludge application, and wastewater irrigation. There exist significant differences in the characteristics of PAEs absorption, accumulation, and distribution among different crops. PAEs not only have negative effects on soil quality, crop growth, and crop physiological and biochemical properties, but also possess bio-accumulative characteristics. The weaknesses in current researches were pointed out, and the suggestions for the further researches were given, e. g., to expand the scope of PAEs pollution survey, to explore the toxic mechanisms of PAEs on crops, and to develop the techniques for in situ remediation of PAEs-polluted soils. PMID:24417132

Wang, Kai-Rong; Cui, Ming-Ming; Shi, Yan-Xi

2013-09-01

180

Treatment of disseminated granuloma annulare with fumaric acid esters  

PubMed Central

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 woman presented with a 25-year history of recalcitrant DGA. On both legs and the abdomen there were erythematous annular plaques. She was treated with FAE in tablet form using two formulations differing in strength (low strength tablets: 30 mg dimethylfumarate, 67 mg monoethylfumarate Ca salt, 5 mg monoethylfumarate Mg salt, 3 mg monoethylfumarate Zn salt; high strength tablets: 120 mg dimethylfumarate, 87 mg monoethylfumarate Ca salt, 5 mg monoethylfumarate Mg salt, 3 mg monoethylfumarate Zn salt). After three-month therapy, an almost complete clearance of skin lesions was achieved. With the exception of temporary lymphopenia, no adverse effects were observed. The patient remained in remission during a six-month follow up period. Conclusions Our observation has demonstrated that FAE is a potentially beneficial therapeutic option for patients with recalcitrant DGA. However controlled trials are necessary to fully explore the efficacy, optimal dosage, and safety of FAE in the management of DGA. PMID:11914154

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

2002-01-01

181

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

PubMed

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

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

2010-02-01

182

Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester  

NASA Astrophysics Data System (ADS)

In this present study, an organic compound Isonicotinic acid methyl ester (INAME) was structurally characterized by FTIR, FT-Raman, and NMR and UV spectroscopy. The optimized geometrical parameters and energies of all different and possible conformers of INAME are obtained from Density Functional Theory (DFT) by B3LYP/6-311++G(d,p) method. There are three conformers (SI, SII-1, and SII-2) for this molecule (ground state). The most stable conformer of INAME is SI conformer. The molecular geometry and vibrational frequencies of INAME in the ground state have been calculated by using HF and density functional method (B3LYP) 6-311++G (d,p) basis set. Detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The computed vibrational frequencies were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (?) and first hyper polarizability (?) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results show that the INAME molecule may have microscopic nonlinear optical (NLO) behavior with non zero values. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method.

Shoba, D.; Periandy, S.; Govindarajan, M.; Gayathri, P.

2015-02-01

183

Divergent effects of eicosapentaenoic and docosahexaenoic acid ethyl esters, and fish oil on hepatic fatty acid oxidation in the rat  

Microsoft Academic Search

The physiological activity of fish oil, and ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) affecting hepatic fatty acid oxidation was compared in rats. Five groups of rats were fed various experimental diets for 15 days. A group fed a diet containing 9.4% palm oil almost devoid of n-3 fatty acids served as a control. The test diets

Dang Diem Hong; Yoko Takahashi; Masay Kushiro; Takashi Ide

2003-01-01

184

Enantioselective liquid-liquid extraction of zopiclone with mandelic acid ester derivatives.  

PubMed

Enantioselective liquid-liquid extraction of zopiclone was conducted by employing a series of (R)-mandelic acid esters as chiral extractants. The effects of concentration of extractant, concentration of zopiclone, type of organic solvent, pH value, and temperature on the extraction efficiency were investigated. (R)-o-chloromandelic acid propyl ester was demonstrated to be an efficient chiral extractant for zopiclone resolution with a maximum enantioselectivity of 1.6. PMID:24123425

Peng, Yangfeng; He, Quan; Zuo, Bin; Niu, Haibo; Tong, Tianzhong; Zhao, Hongliang

2013-12-01

185

Enzymatic synthesis of carbohydrate esters of fatty acid (I) esterification of sucrose, glucose, fructose and sorbitol  

Microsoft Academic Search

The authors attempted to synthesize carbohydrate esters of fatty acids enzymatically in order to overcome the problems associated\\u000a with the chemical processes for the synthesis of commercial sucrose esters. The enzymes used were lipases from microorganisms\\u000a belonging toRhyzopus, Enterbacterium, Aspergillus, Pseudomonas, Chromobacterium, Candida, Mucor andPenicillium. Fatty acids (stearic, oleic and linoleic) and carbohydrates (sucrose, glucose, fructose and sorbitol) used for

Hajime Seino; Tsuyoshi Uchibori; Toshiyuki Nishitani; Sachiko Inamasu

1984-01-01

186

Ammonolysis of esters of hydroxybenzoic acids on a boron phosphate catalyst  

SciTech Connect

In this investigation boron phosphate catalyst was used for ammonolysis of methyl and ethyl esters of salicylic and 4-hydroxybenzoic acids. It was shown that ammonolysis of methyl and ethyl esters of salicylic and 4-hydroxybenzoic acids in presence of boron phosphate catalyst at a ratio of 3-7 moles of ammonia per mole of ester in a contact time of 1-5 sec at 380-400/sub 0/ can be used for obtaining o- and p- hydroxybenzonitriles in yields of over 90% of the theoretical.

Suvorov, B.V.; Bukeikhanov, N.R.; Li, L.V.; Zulkasheva, A.Z.

1987-09-10

187

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

DOEpatents

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.

Moens, Luc (Lakewood, CO)

1999-01-01

188

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

DOEpatents

A process is disclosed for preparing an acid addition salt of delta-aminolevulinic acid comprising. The process involves 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 to form a suspension of an alkyl 5-(N,N-diformylamino) levulinate ester; and hydrolyzing the alkyl 5-(N,N-diformylamino) levulinate with an inorganic acid to form an acid addition salt of delta-amino levulinic acid.

Moens, L.

1999-05-25

189

Fatty Acid Phytyl Ester Synthesis in Chloroplasts of Arabidopsis[W  

PubMed Central

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

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

190

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

NASA Astrophysics Data System (ADS)

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.

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

2015-03-01

191

Synthetic transformations of higher terpenoids: XV. Transformations of azlactone derived from 16-formyllambertianic acid methyl ester  

Microsoft Academic Search

Condensation of 16-formyllambertianic acid methyl ester with hippuric acid gave methyl 15,16-epoxy-16-[(4Z)-5-oxo-2-phenyl-4,5-dihydrooxazol-4-ylidenemethyl]labda-8(20),13(16),14-trien-19-oate\\u000a which underwent ready transformation into 2-benzoylamino-3-(2-furyl)acrylic acid of the labdanoid series. Reactions of the\\u000a diterpenoid azlactone with amines and ?-amino acid esters led to the formation of the corresponding carbamoylvinylbenzamides\\u000a and N-(2-benzoylaminoacryloyl) amino acid esters, and furylacrylic acid hydrazides were formed in reactions with hydrazines. Cyclization\\u000a of the

Yu. V. Kharitonov; E. E. Shul’ts; M. M. Shakirov; G. A. Tolstikov

2007-01-01

192

Synthesis of cellulose-fatty acid esters for use as biodegradable plastics  

Microsoft Academic Search

Long-chain fatty acid carbohydrate esters (FACE) were synthesized by the acid chloride-pyridine reaction to different degrees of substitution (DS). The hydrolyzed soybean oil was used as the source of unsaturated fatty acids. High molecular weight FACE polymers are insoluble in common solvents, such as benzene, toluene, THF, etc., and are highly water resistant. However, FACE polymers of hydrolyzed cellulose (MW

Pinglang Wang; Bernard Y. Tao

1995-01-01

193

Preparation of fatty acid methyl esters from Osage orange (Maclura pomifera) oil and evaluation as biodiesel  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fatty acid methyl esters were prepared in high yield by transesterification of Osage orange (Maclura pomifera) oil. Extracted using supercritical CO2, the crude oil was initially treated with mineral acid and methanol to lower its content of free fatty acids, thus rendering it amenable to homogeneou...

194

Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

195

Preparation of tert-butyl esters via Pd-catalyzed tert-butoxycarbonylation of (hetero)aryl boronic acid derivatives.  

PubMed

A novel protocol to synthesize tert-butyl esters from boronic acids or boronic acid pinacol esters and di-t-butyl dicarbonate has been successfully achieved. The cross-coupling reactions can produce up to 94% yields by using palladium acetate and triphenylphosphine as catalyst system, dioxane as a solvent. Moreover, a wide range of substrates including benzenes, pyridines, and quinolines boronic acids or boronic acid pinacol esters can fit with this system as well. PMID:24655126

Li, Xinjian; Zou, Dapeng; Zhu, Helong; Wang, Yaping; Li, Jingya; Wu, Yangjie; Wu, Yusheng

2014-04-01

196

Branched chain amino acid metabolism in the biosynthesis of Lycopersicon pennellii glucose esters  

SciTech Connect

Lycopersicon pennellii Corr. (D'Arcy) an insect-resistant, wild tomato possesses high densities of glandular trichomes which exude a mixture of 2,3,4-tri-O-acylated glucose esters that function as a physical impediment and feeding deterrent to small arthropod pests. The acyl moieties are branched C{sub 4} and C{sub 5} acids, and branched and straight chain C{sub 10}, C{sub 11}, and C{sub 12} acids. The structure of the branched acyl constituents suggests that the branched chain amino acid biosynthetic pathway participates in their biosynthesis. ({sup 14}C)Valine and deuterated branched chain amino acids (and their oxo-acid derivatives) were incorporated into branched C{sub 4} and C{sub 5} acid groups of glucose esters by a process of transamination, oxidative decarboxylation and subsequent acylation. C{sub 4} and C{sub 5} branched acids were elongated by two carbon units to produce the branched C{sub 10}-C{sub 12} groups. Norvaline, norleucine, allylglycine, and methionine also were processed into acyl moieties and secreted from the trichomes as glucose esters. Changes in the acyl composition of the glucose esters following sulfonylurea herbicide administration support the participation of acetohydroxyacid synthetase and the other enzymes of branched amino acid biosynthesis in the production of glucose esters.

Walters, D.S.; Steffens, J.C. (Cornell Univ., Ithaca, NY (USA))

1990-08-01

197

Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester.  

PubMed

In this present study, an organic compound Isonicotinic acid methyl ester (INAME) was structurally characterized by FTIR, FT-Raman, and NMR and UV spectroscopy. The optimized geometrical parameters and energies of all different and possible conformers of INAME are obtained from Density Functional Theory (DFT) by B3LYP/6-311++G(d,p) method. There are three conformers (SI, SII-1, and SII-2) for this molecule (ground state). The most stable conformer of INAME is SI conformer. The molecular geometry and vibrational frequencies of INAME in the ground state have been calculated by using HF and density functional method (B3LYP) 6-311++G (d,p) basis set. Detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The computed vibrational frequencies were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (?) and first hyper polarizability (?) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results show that the INAME molecule may have microscopic nonlinear optical (NLO) behavior with non zero values. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method. PMID:25459608

Shoba, D; Periandy, S; Govindarajan, M; Gayathri, P

2015-02-01

198

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 ...

199

Medium chain fatty acid ethyl esters - activation of antimicrobial effects by Malassezia enzymes.  

PubMed

Free medium and short chain fatty acids are known to have broad antimicrobial activity. However, their practical use in topical therapy is limited by their intensive smell and acidity. Surprisingly, a nearly identical antimicrobial effect was found with the ethyl ester derivatives of these fatty acids, but only against Malassezia (M.) yeast, not against Candida spp. Obviously, these esters are hydrolysed by M. enzymes, thus generating a selective activation of antimicrobial activity especially in areas well populated with these yeast ('targeting'). Octanoic acid ethyl ester (CAS 106-32-1) was found to be most suitable. In an agar dilution test, the minimal inhibitory concentrations against M. globosa, M. pachydermatis and M. sympodialis, respectively, ranged between ~5 and 10 mmol l(-1) after 10 days of incubation. The effect started immediately and was not delayed by other lipid sources applied simultaneously. Based on these data, fatty acid monoesters may represent a new therapeutic concept in M.-associated diseases. PMID:25676074

Mayser, Peter

2015-04-01

200

76 FR 41135 - 2-Propenoic acid, 2-methyl-, phenylmethyl ester, polymer with 2-propenoic acid and sodium 2...  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2011-0327; FRL-8878-4] 2-Propenoic acid, 2-methyl-, phenylmethyl ester, polymer with 2- propenoic acid and sodium 2-methyl-2-[(1-oxo-2-propen-1-yl...propanesulfonate (1:1), peroxydisulfuric acid ([HO)S(O)2]202) sodium...

2011-07-13

201

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

NASA Technical Reports Server (NTRS)

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.

Chisnell, J. R.

1984-01-01

202

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

E-print Network

(trimethylene carbon- ate), and most notably poly(glycolic acid) and poly(lactic acid), have met wide acceptance or succinic acids have also been reported.20 Poly( -caprolactone) is one polymer that has been used widely- lactone) is because of its slow degradation rate which does not create acidic microenvironments like poly(glycolic

203

Analysis of chemical structure of fluoro-containing copolyamic acid methyl esters and its effect on the thermal imidization process  

Microsoft Academic Search

Copolyamic acid methyl esters were directly synthesized from 2,5-dicarbomethoxy terephthalic acid (p-PMDE) and 4,4?-oxydianiline (ODA) and fluoro-containing diamines using phenyl phosphonic dichloride. The average sequence lengths of the copolyamic acid methyl esters were controlled by stoichiometric unbalance and monitored by proton nuclear magnetic resonance spectroscopy (1H-NMR). The effect of chemical structure of copolyamic methyl esters on thermal cyclization to the

Seung Koo Park; Soo Young Park; Chul Joo Lee

2000-01-01

204

Paper chromatography of unsaturated fatty acid esters as their mercuric acetate addition compounds  

Microsoft Academic Search

Summary  A method is described by which unsaturated fatty acid esters can be separated and identified by reversed-phase paper chromatography.\\u000a The procedure is based upon the formation of the mercuric acetate addition compounds of the esters and the detection of the\\u000a compounds on the chromatograms, using the sensitive color reaction with diphenylcarbazone. The application of this technique\\u000a to the analysis of

Yoshiyuki Inouye; Manjiro Noda; Osamu Hirayama

1955-01-01

205

Picolinyl esters for the structural determination of fatty acids by GC\\/MS  

Microsoft Academic Search

The position of unsaturation, chain branching, and other structural features of fatty acids are not often apparent from the\\u000a mass spectra of common derivatives such as methyl esters because of factors such as charge location at the carboxy termiunus\\u000a and migration of double bonds. The spectra of picolinyl esters, on the other hand, contain fragment ions that provide this\\u000a information.

David J. Harvey

1998-01-01

206

Caffeic acid phenethyl ester inhibits liver fibrosis in rats  

PubMed Central

AIM: To investigate the hepatoprotective effects and antioxidant activity of caffeic acid phenethyl ester (CAPE) in rats with liver fibrosis. METHODS: A total of 75 male Sprague-Dawley rats were randomly assigned to seven experimental groups: a normal group (n = 10), a vehicle group (n = 10), a model group (n = 15), a vitamin E group (n = 10), and three CAPE groups (CAPE 3, 6 and 12 mg/kg, n = 10, respectively). Liver fibrosis was induced in rats by injecting CCl4 subcutaneously, feeding with high fat forage, and administering 30% alcohol orally for 10 wk. Concurrently, CAPE (3, 6 and 12 mg/kg) was intraperitoneally administered daily for 10 wk. After that, serum total bilirubin (TBil), aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured to assess hepatotoxicity. To investigate antioxidant activity of CAPE, malondialdehyde (MDA), glutathione (GSH) levels, catalase (CAT) and superoxide dismutase (SOD) activities in liver tissue were determined. Moreover, the effect of CAPE on ?-smooth muscle actin (?-SMA), a characteristic hallmark of activated hepatic stellate cells (HSCs), and NF-E2-related factor 2 (Nrf2), a key transcription factor for antioxidant systems, was investigated by immunohistochemistry. RESULTS: Compared to the model group, intraperitoneal administration of CAPE decreased TBil, ALT, and AST levels in liver fibrosis rats (P < 0.05), while serum TBil was decreased by CAPE in a dose-dependent manner. In addition, the liver hydroxyproline contents in both the 6 and 12 mg/kg CAPE groups were markedly lower than that in the model group (P < 0.05 and P < 0.001, respectively). CAPE markedly decreased MDA levels and, in turn, increased GSH levels, as well as CAT and SOD activities in liver fibrosis rats compared to the model group (P < 0.05). Moreover, CAPE effectively inhibited ?-SMA expression while increasing Nrf2 expression compared to the model group (P < 0.01). CONCLUSION: The protective effects of CAPE against liver fibrosis may be due to its ability to suppress the activation of HSCs by inhibiting oxidative stress. PMID:25852274

Li, Mei; Wang, Xiu-Fang; Shi, Juan-Juan; Li, Ya-Ping; Yang, Ning; Zhai, Song; Dang, Shuang-Suo

2015-01-01

207

Radiation damage produced in powder of ?-(methylamino)isobutyric acid, ? -aminoisobutyric acid methyl ester hydrochloride and diethylmalonic acid  

Microsoft Academic Search

The electron paramagnetic resonance spectra of ?-irradiated powders of ?-(methylamino)isobutyric acid – CH3NHC(CH3)2COOH, ? -aminoisobutyric acid methyl ester hydrochloride – NH2(CH3)2CCOOCH3 HCl, and diethylmalonic acid – (CH3CH2)2C(COOH)2 have been investigated at room temperature. It has been found that ? -irradiation produces the (CH3)2C?COOH radical in the first, the (CH3)2C?COOCH3 radical in the second and the (CH3CH2)2C?COOH radical in the third

M. Halim Ba?kan; ?emsettin Osmano?lu; I. Ye?im Dicle

2009-01-01

208

Radiation damage produced in powder of alpha-(methylamino)isobutyric acid, alpha -aminoisobutyric acid methyl ester hydrochloride and diethylmalonic acid  

Microsoft Academic Search

The electron paramagnetic resonance spectra of gamma-irradiated powders of alpha-(methylamino)isobutyric acid - CH3NHC(CH3)2COOH, alpha -aminoisobutyric acid methyl ester hydrochloride - NH2(CH3)2CCOOCH3 HCl, and diethylmalonic acid - (CH3CH2)2C(COOH)2 have been investigated at room temperature. It has been found that gamma -irradiation produces the (CH3)2C˙COOH radical in the first, the (CH3)2C˙COOCH3 radical in the second and the (CH3CH2)2C˙COOH radical in the third

M. Halim Baskan; Semsettin Osmanoglu; I. Yesim Dicle

2009-01-01

209

Effect of caffeic acid phenethyl ester on myringosclerosis development in the tympanic membrane of rat.  

PubMed

Myringosclerosis is hyalinization and calcification of certain areas of the tympanic membrane, especially the fibrous lamina propria layer and appears as white sclerotic lesions. Ventilation tube insertion is one of the most performed operations in the pediatric otorhinolaryngology practice to treat chronic otitis media with effusion. Myringosclerosis is a very common sequela of ventilation tube insertion. In this experimental study, our aim was to show the histopathological effects of caffeic acid phenethyl ester on myringosclerosis development in rat tympanic membrane after myringotomy. The rats were randomly categorized into four experimental groups including the comparison group (n = 4), non-treated group (n = 7), the saline (control) group (n = 7), the caffeic acid phenethyl ester group (n = 7). Non-treated group did not receive any treatment for 15 days. Saline (2.5 mL/kg, intraperitoneal) was administered to the third group once a day for 15 days. Fourth group received caffeic acid phenethyl ester intraperitoneally once a day at a dose of 10 ?mol/kg for 15 days. Myringotomy was performed on the right tympanic membrane of all rats except comparison group using a sterile pick with the help of an operating microscope. Histopathological examination of myringosclerosis formation was done by a pathologist under light microscope. In histopathological analysis of groups, the severity of inflammation was milder in caffeic acid phenethyl ester group compared to non-treated and saline groups (p < 0.05). There was less myringosclerotic plaques in caffeic acid phenethyl ester group than in non-treated and saline groups (p < 0.05). TM thickness measurements were very close to each other in non-treated and saline groups. The tympanic membrane thickness of caffeic acid phenethyl ester group was much thinner than the other two groups (p < 0.05). Caffeic acid phenethyl ester decreases inflammation severity and the formation of myringosclerotic plaques. These two effects resulted in thinner tympanic membranes of rats which were treated with caffeic acid phenethyl ester. As a result, caffeic acid phenethyl ester has potential preventive effects on myringosclerosis development after myringotomy and ventilation tube insertion. PMID:24281567

Kinis, Vefa; Ozbay, Musa; Alabalik, Ulas; Gul, Aylin; Yilmaz, Beyhan; Ozkurt, Fazi Emre; Sengul, Engin; Topcu, Ismail

2015-01-01

210

77 FR 20314 - 2-Propenoic Acid, 2-Methyl-, 2-Ethylhexyl Ester, Telomer With 1-Dodecanethiol, Ethenylbenzene and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2011-0975; FRL-9339-9] 2-Propenoic Acid, 2-Methyl-, 2-Ethylhexyl Ester...tolerance for residues of 2-Propenoic acid, 2-methyl-, 2- ethylhexyl ester...permissible level for residues of 2-Propenoic acid, 2-methyl-, 2-ethylhexyl...

2012-04-04

211

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-08-18

212

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Sulfuric acid, mono-C9-11-alkyl esters...Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11 -alkyl esters...chemical substance identified as sulfuric acid, mono-C9-11...

2014-07-01

213

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Sulfuric acid, mono-C9-11-alkyl esters...Chemical Substances § 721.3130 Sulfuric acid, mono-C9- 11-alkyl esters...chemical substance identified as sulfuric acid, mono-C9-11...

2011-07-01

214

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Sulfuric acid, mono-C9-11-alkyl esters...Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11 -alkyl esters...chemical substance identified as sulfuric acid, mono-C9-11...

2012-07-01

215

The interaction between zinc deficiency and copper toxicity as it affects the silicic acid uptake mechanisms in Thalassiosira pseudonana  

Microsoft Academic Search

Zinc-deficient cultures of Thalassiosira pseudonana exhibited reduced silicic acid uptake rates. Copper toxicity decreased the silicic acid uptake rate at any zinc concentration. This resulted in the uptake rate being a function of the ratio in the medium of the cupric ion activity to the zinc activity rather than of either metal activity separately. These results are consistent with a

JOHN G. RUETER; F. M. M. MOREL

1981-01-01

216

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

... 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...

2010-04-01

217

Inhibitory Effects of Caffeic Acid Phenethyl Ester Derivatives on Replication of Hepatitis C Virus  

PubMed Central

Caffeic acid phenethyl ester (CAPE) has been reported as a multifunctional compound. In this report, we tested the effect of CAPE and its derivatives on hepatitis C virus (HCV) replication in order to develop an effective anti-HCV compound. CAPE and CAPE derivatives exhibited anti-HCV activity against an HCV replicon cell line of genotype 1b with EC50 values in a range from 1.0 to 109.6 µM. Analyses of chemical structure and antiviral activity suggested that the length of the n-alkyl side chain and catechol moiety are responsible for the anti-HCV activity of these compounds. Caffeic acid n-octyl ester exhibited the highest anti-HCV activity among the tested derivatives with an EC50 value of 1.0 µM and an SI value of 63.1 by using the replicon cell line derived from genotype 1b strain Con1. Treatment with caffeic acid n-octyl ester inhibited HCV replication of genotype 2a at a similar level to that of genotype 1b irrespectively of interferon signaling. Caffeic acid n-octyl ester could synergistically enhance the anti-HCV activities of interferon-alpha 2b, daclatasvir, and VX-222, but neither telaprevir nor danoprevir. These results suggest that caffeic acid n-octyl ester is a potential candidate for novel anti-HCV chemotherapy drugs. PMID:24358168

Shen, Hui; Yamashita, Atsuya; Nakakoshi, Masamichi; Yokoe, Hiromasa; Sudo, Masashi; Kasai, Hirotake; Tanaka, Tomohisa; Fujimoto, Yuusuke; Ikeda, Masanori; Kato, Nobuyuki; Sakamoto, Naoya; Shindo, Hiroko; Maekawa, Shinya; Enomoto, Nobuyuki; Tsubuki, Masayoshi; Moriishi, Kohji

2013-01-01

218

The effect of caffeic acid phenethyl ester on bacterial translocation and intestinal damage in cholestatic rats.  

PubMed

We investigated the effect of caffeic acid phenethyl ester in rat ileum injury induced by chronic biliary obstruction. Swiss albino rats were divided into three groups: Group 1, sham (n = 7); Group 2, common bile duct ligation (n = 7); and Group 3, common bile duct ligation plus caffeic acid phenethyl ester (n = 7). In the caffeic acid phenethyl ester-treated rats, ileum tissue levels of malondialdehyde and myeloperoxidase were significantly lower than those of the bile duct-ligated rats (P < 0.001). The levels of tumor necrosis factor-alpha, interleukin-6, and interleukin-1alpha in the caffeic acid phenethyl ester group were significantly lower than those in the bile duct ligation group (P < 0.03, P < 0.01, and P < 0.02 respectively). The present study demonstrates that intraperitoneal administration of caffeic acid phenethyl ester in bile duct-ligated rats reduces intestinal oxidative stress. This effect may be useful in the preservation of intestinal damage in cholestasis. PMID:16983503

Ara, Cengiz; Esrefoglu, Mukaddes; Polat, Alattin; Isik, Burak; Aladag, Murat; Gul, Mehmet; Ay, Selma; Tekerleklioglu, M Sait; Yilmaz, Sezai

2006-10-01

219

Fatty acid ethyl esters are present in human serum after ethanol ingestion  

Microsoft Academic Search

The aim of the study was to determine whether fatty acid ethyl esters, nonoxidative products of ethanol metabolism selectively present in organs damaged by ethanol abuse, are de- tectable in the serum after ethanol ingestion. Serum samples of hospital emergency room patients with positive (n = 32) and negative (n = 5) blood ethanol levels were assayed for fatty acid

Kathleen M. Doyle; David A. Bird; Salih Al-Salihi; Youseff Hallaq; Joanne E. Cluette-Brown; Kendrick A. Goss; Michael Laposata

220

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2014 CFR

...glycol or glycerol with long chain monobasic acids containing from...obtained by the ozonization of long chain alpha -olefins, the unreacted...75 percent by weight straight chain alpha -olefins and not more...locations.html. (2) Acid value 15-25 for each ester...

2014-04-01

221

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2010 CFR

...glycol or glycerol with long chain monobasic acids containing from...obtained by the ozonization of long chain alpha -olefins, the unreacted...75 percent by weight straight chain alpha -olefins and not more...locations.html. (2) Acid value 15-25 for each ester...

2010-04-01

222

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2011 CFR

...glycol or glycerol with long chain monobasic acids containing from...obtained by the ozonization of long chain alpha -olefins, the unreacted...75 percent by weight straight chain alpha -olefins and not more...locations.html. (2) Acid value 15-25 for each ester...

2011-04-01

223

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2013 CFR

...glycol or glycerol with long chain monobasic acids containing from...obtained by the ozonization of long chain alpha -olefins, the unreacted...75 percent by weight straight chain alpha -olefins and not more...locations.html. (2) Acid value 15-25 for each ester...

2013-04-01

224

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.  

Code of Federal Regulations, 2012 CFR

...glycol or glycerol with long chain monobasic acids containing from...obtained by the ozonization of long chain alpha -olefins, the unreacted...75 percent by weight straight chain alpha -olefins and not more...locations.html. (2) Acid value 15-25 for each ester...

2012-04-01

225

Hydrazone-palladium-catalyzed allylic arylation of cinnamyloxyphenylboronic acid pinacol esters.  

PubMed

Allylic arylation of cinnamyloxyphenylboronic acid pinacol esters 3, which have arylboronic acid moiety and allylic ether moiety, using a hydrazone 1d-Pd(OAc)2 system proceeded and gave the corresponding 1,3-diarylpropene derivatives 4 with a phenolic hydroxyl group via a selective coupling reaction of the ?-allyl intermediate to the boron-substituted position of the leaving group. PMID:24962496

Watanabe, Kohei; Mino, Takashi; Abe, Taichi; Kogure, Taketo; Sakamoto, Masami

2014-07-18

226

Molecular assembly, interfacial rheology and foaming properties of oligofructose fatty acid esters.  

PubMed

Two major types of food-grade surfactants used to stabilize foams are proteins and low molecular weight (LMW) surfactants. Proteins lower the surface tension of interfaces and tend to unfold and stabilize the interface by the formation of a visco-elastic network, which leads to high surface moduli. In contrast, LMW surfactants lower the surface tension more than proteins, but do not form interfaces with a high modulus. Instead, they stabilize the interface through the Gibbs-Marangoni mechanism that relies on rapid diffusion of surfactants, when surface tension gradients develop as a result of deformations of the interface. A molecule than can lower the surface tension considerably, like a LMW surfactant, but also provide the interface with a high modulus, like a protein, would be an excellent foam stabilizer. In this article we will discuss molecules with those properties: oligofructose fatty acid esters, both in pure and mixed systems. First, we will address the synthesis and structural characterization of the esters. Next, we will address self-assembly and rheological properties of air/water interfaces stabilized by the esters. Subsequently, this paper will deal with mixed systems of mono-esters with either di-esters and lauric acid, or proteins. Then, the foaming functionality of the esters is discussed. PMID:24292507

van Kempen, Silvia E H J; Schols, Henk A; van der Linden, Erik; Sagis, Leonard M C

2014-01-01

227

Kinetics of sulfuric acid leaching of low-grade zinc silicate ore  

Microsoft Academic Search

The results of a leaching kinetics study of low-grade zinc silicate ore with sulfuric acid are presented. Effect of ore particle size, reaction temperature, and acid concentration on zinc dissolution rate were determined. The results obtained show that leaching of about 94% of zinc is achieved using ?200+270 mesh ore particle size at a reaction temperature of 70°C for 180

E. A Abdel-Aal

2000-01-01

228

Synthesis of geranyl and citronellyl esters of coconut oil fatty acids through alcoholysis by Rhizomucor miehei lipase catalysis  

Microsoft Academic Search

Synthesis of geranyl and citronellyl esters of mixed fatty acids has been investigated by alcoholysis of coconut oil (CNO)\\u000a using Rhizomucor miehei lipase. CNO fatty acid esters of geraniol and citronellol have unique mild flavors that can be used in food materials. Both\\u000a geraniolysis and citronellolysis of CNO produce flavor esters in good yield. Depending on substrate concentration the molar

B. K. De; T. Chatterjee; D. K. Bhattacharyya

1999-01-01

229

Effect of physical ageing on properties of PLA plasticized with oligomeric esters of lactic acid  

NASA Astrophysics Data System (ADS)

Two oligomeric esters of lactic acid with carboxyl or hydroxyl terminal groups were employed to plasticize polylactic acid. The miscibility of the blends as well as the mechanical, thermal and gas/vapour transport properties were tested as a function of plasticizer content and of physical ageing. A ductile PLA behavior was obtained with the addition of at least 20 wt% of both esters supplying an increase of elongation at break values higher than 400%. These blends retain their ductile feature also after ageing. Finally migration tests proved the compliance of these materials with the EU regulation for food contact plastics.

Castaldo, R.; Ambrogi, V.; Avella, M.; Avolio, R.; Carfagna, C.; Cocca, M.; Errico, M. E.; Gentile, G.

2014-05-01

230

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.  

Code of Federal Regulations, 2010 CFR

... false Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...9511 Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...as silicic acid (H6 SiO2 O7 ) magnesium, strontium...

2010-07-01

231

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.  

Code of Federal Regulations, 2011 CFR

... false Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...9511 Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium...as silicic acid (H6 SiO2 O7 ) magnesium, strontium...

2011-07-01

232

40 CFR 721.9511 - Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium and europium-doped.  

Code of Federal Regulations, 2012 CFR

... false Silicic acid (H6SiO2O7), magnesium, strontium salt(1:1:2), dysprosium... Silicic acid (H6 SiO2 O7 ), magnesium, strontium salt(1:1:2), dysprosium...as silicic acid (H6 SiO2 O7 ) magnesium, strontium...

2012-07-01

233

Discrimination among geometrical isomers of ? -linolenic acid methyl ester using low energy electron ionization mass spectrometry  

Microsoft Academic Search

There is a consensus that electron impact ionization mass spectrometry is not capable of discriminating among geometrical\\u000a isomers of unsaturated fatty acid methyl esters (and in general olefinic compounds). In this paper, we report the identification\\u000a of all eight geometrical isomers of ?-linolenic acid, one of the few essential ?-3 fatty acids that has attracted great attention, using low-energy electron

Leila Hejazi; Diako Ebrahimi; Michael Guilhaus; D. Brynn Hibbert

2009-01-01

234

Fatty acids and their sucrose esters affect the properties of fish skin gelatin-based film  

Microsoft Academic Search

The effects of fatty acids (FA) [palmitic acid (PA) and stearic acid (SA)] and their sucrose esters (FASE) on the mechanical\\u000a properties, water vapor permeability (WVP), light transmission, and color of films from bigeye snapper and brownstripe red\\u000a snapper skin gelatins were investigated. Tensile strength (TS) of films generally decreased with the addition of FA (ppp<0.05). However, films containing FASE

Akkasit Jongjareonrak; Soottawat Benjakul; Wonnop Visessanguan; Munehiko Tanaka

2006-01-01

235

Biosynthesis of chylomicron t riacylgl ycerols by rats fed glyceryl or alkyl esters of menhaden oil fatty acids  

Microsoft Academic Search

We have previously shown great similarity in the dis- tribution of fatty acids in the sn-1 and sn-3 positions of the chylomicron triacylglycerols (TG) from rats fed menhaden oil or its ethyl esters, and have proposed that the acylglycerol products of the phosphatidic acid (PA) pathway (ester feeding) are hydro- lyzed to 2-monoacylglycerols (2-MG) prior to reconversion to TG via

A. Kuksis; J. J. Myher

236

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

Microsoft Academic Search

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

A. Kuksis; J. J. Myher

237

ISOLATION AND CHARACTERIZATION OF AN ACID, BILE SALT-INDEPENDENT, RETINYL ESTER HYDROLASE FROM RAT LIVER MICROSOMES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous work in this laboratory has revealed the presence of both acidic and neutral bile-salt independent retinyl ester hydrolase activities in rat liver homogenates. Here we present the purification, identification and characterization of an acid retinyl ester hydrolase activity from solubilized ...

238

Ionic liquids as novel solvents for the synthesis of sugar fatty acid ester.  

PubMed

Sugar fatty acid esters are bio-surfactants known for their non-toxic, non-ionic, and high biodegradability . With great emulsifying and conditioning effects, sugar fatty acids are widely used in the food, pharmaceutical, and cosmetic industries. Biosynthesis of sugar fatty acid esters has attracted growing attention in recent decades. In this study, the enzymatic synthesis of sugar fatty acid esters in ionic liquids was developed, optimized, and scaled up. Reaction parameters affecting the conversion yield of lipase-catalyzed synthesis of glucose laurate from glucose and vinyl laurate (i.e. temperature, vinyl laurate/glucose molar ratio, and enzyme loads) were optimized by response surface methodology (RSM). In addition, production was scaled up to 2.5 L, and recycling of enzyme and ionic liquids was investigated. The results showed that under optimal reaction conditions (66.86 °C, vinyl laurate/glucose molar ratio of 7.63, enzyme load of 73.33 g/L), an experimental conversion yield of 96.4% was obtained which is close to the optimal value predicted by RSM (97.16%). A similar conversion yield was maintained when the reaction was carried out at 2.5 L. Moreover, the enzymes and ionic liquids could be recycled and reused effectively for up to 10 cycles. The results indicate the feasibility of ionic liquids as novel solvents for the biosynthesis of sugar fatty acid esters. PMID:25124865

Mai, Ngoc Lan; Ahn, Kihun; Bae, Sang Woo; Shin, Dong Woo; Morya, Vivek Kumar; Koo, Yoon-Mo

2014-12-01

239

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

Code of Federal Regulations, 2014 CFR

...New Uses for Specific Chemical Substances § 721...alkylstannylene ester, reaction products with inorganic...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...alkylstannylene ester, reaction products with...

2014-07-01

240

Cytotoxic evaluation of semisynthetic ester and amide derivatives of oleanolic acid.  

PubMed

Although a number of chemicals have been isolated from Lantana camara, only a few have been evaluated for their biological significance. As part of our drug discovery program for cytotoxic agents from Indian medicinal plants, roots of L. camara L. were chemically investigated, which resulted in the isolation and identification of a cytotoxic agent, oleanolic acid (1b) as a major constituent. Oleanolic acid was converted into six semi-synthetic ester (2-7) and seven amide (8-14) derivatives. The ester derivatives (2-7) showed 3-6 times more selective activity than 1b against the human ovarian cancer cell line (IGR-OV-1), while amide derivatives 8-14 showed 16-53 times more selective activity against the human lung cancer cell line (HOP-62). Structure activity relationship within the ester (2-7) and amide (8-14) derivatives are discussed. PMID:21121249

Gupta, Shikha; Kalani, Komal; Saxena, Mohit; Srivastava, Santosh K; Agrawal, Satyam K; Suri, Nitasha; Saxena, Ajit K

2010-10-01

241

Characterization of modified calcium-silicate cements exposed to acidic environment  

SciTech Connect

Portland cement which is used as a binder in concrete in the construction industry has been developed into a biomaterial. It is marketed as mineral trioxide aggregate and is used in dentistry. This material has been reported to be very biocompatible and thus its use has diversified. The extended use of this material has led to developments of newer versions with improved physical properties. The aim of this study was to evaluate the effect of acidic environments found in the oral cavity on fast setting calcium silicate cements with improved physical properties using a combination of techniques. Two fast setting calcium silicate cements (CSA and CFA) and two cement composites (CSAG and CFAG) were assessed by subjecting the materials to lactic acid/sodium lactate buffer gel for a period of 28 days. At weekly intervals the materials were viewed under the tandem scanning confocal microscope (TSM), and scanning electron microscope (SEM). The two prototype cements exhibited changes in their internal chemistry with no changes in surface characteristics. Since the changes observed were mostly sub-surface evaluation of surface characteristics of cement may not be sufficient in the determination of chemical changes occurring. - Research Highlights: {yields} An acidic environment affects modified fast setting calcium silicate-based cements. {yields} No surface changes are observed in acidic environment. {yields} An acidic environment causes sub-surface changes in the material chemistry which are only visible in fractured specimens. {yields} A combination of techniques is necessary in order to evaluate the chemical changes occurring.

Camilleri, Josette, E-mail: josette.camilleri@um.edu.mt

2011-01-15

242

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

PubMed

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

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

2014-02-15

243

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

DOEpatents

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.

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

1999-01-01

244

Fatty acid esters of monochloropropanediol (MCPD) and glycidol in refined edible oils.  

PubMed

Recently, fatty acid esters of monochloropropanediol (MCPD) and that of glycidol have been reported in refined edible oils. Since then a wealth of research has been published on the factors influencing the formation of these contaminants in foods. It can be noted that the predominant precursors in a given matrix will not necessarily be the same as in other matrices. Further, proven relationships in the past between precursors responsible for free MCPD or free glycidol formation will not necessarily be valid for their fatty acid-esterified counterparts. This review attempts to summarise the current status of the literature as it pertains to the reasons surrounding the manifestation of MCPD esters and glycidyl esters in oils and fats. Recent efforts to mitigate the levels of these contaminants were highlighted and put into the context of their respective reaction matrices. As more accurate occurrence data for MCPD esters and glycidyl esters in other foods are collected, more targeted mitigation experiments can be formulated with respect to the reaction matrices under investigation. PMID:23020600

Craft, B D; Chiodini, A; Garst, J; Granvogl, M

2013-01-01

245

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

Microsoft Academic Search

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

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

1967-01-01

246

ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. II. ACID AND GENERAL BASE CATALYZED HYDROLYSIS  

EPA Science Inventory

SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate acid and neutral hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition states of a ...

247

Contamination of vegetable oils marketed in Italy by phthalic acid esters  

Microsoft Academic Search

More than 90% of the phthalic acid esters (PAEs) produced in Europe is used to plasticize polyvinyl chloride (PVC). Animal studies have shown that some PAEs can damage the liver and interfere with the endocrine system, whereas data on the toxic effects on humans are inconsistent. For the general population, the diet is believed to be the main source of

Natalia Nanni; Katell Fiselier; Koni Grob; Mauro Di Pasquale; Laura Fabrizi; Paolo Aureli; Ettore Coni

2011-01-01

248

Antithyroid effect of a food or drug preservative: 4-hydroxybenzoic acid methyl ester  

Microsoft Academic Search

Summary 4-hydroxybenzoic acid methyl ester (methylparaben) inhibits organification of iodide by isolated hog thyroid cells. The concentration which produces a 50% inhibition was about 2.0×10?4M. A similar inhibition was observed in nonstimulated and TSH- or dibutyryl cyclic AMP-stimulated cells. Neither iodide uptake nor cyclic AMP generation were altered by methylparaben.

B. Rousset

1981-01-01

249

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...

250

Synthesis of D-allose fatty acid esters via lipase-catalyzed regioselective transesterification.  

PubMed

The acylation of the rare sugar, D-allose (the C-3 epimer of D-glucose), with fatty acid vinyl esters was successfully carried out using Candida antarctica lipase in acetonitrile at 45 degrees C to give D-allose 6-alkanoates with high regioselectivity in good yields. PMID:15849425

Afach, Ghanwa; Kawanami, Yasuhiro; Izumori, Ken

2005-04-01

251

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

Microsoft Academic Search

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

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

2003-01-01

252

Esterification and Transesterification of greases to fatty acid methyl esters with highly active diphenylamine salts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diphenylamine sulfate (DPAS) and diphenylamine hydrochloride (DPACl) salts were found to be highly active catalysts for esterification and transesterification of inexpensive greases to fatty acid methyl esters (FAME). In the presence of catalytic amounts of DPAS or DPACl and excess methanol, the fr...

253

Lack of spermatotoxic effects of methyl and ethyl esters of p-hydroxybenzoic acid in rats  

Microsoft Academic Search

Parabens are alkyl esters of p-hydroxybenzoic acid widely used as preservatives in foodstuffs, cosmetics toiletries and pharmaceuticals. These compounds are known to exert a weak estrogenic activity in estrogen receptor assays in vitro. In addition butyl and propyl parabens show uterotrophic activity in vivo. It was previously shown that exposure of post-weaning rats and mice to butyl or propyl parabens

Shinshi Oishi

2004-01-01

254

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

Microsoft Academic Search

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

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

2005-01-01

255

Syntheses of fluorooxindole and 2-fluoro-2-arylacetic acid derivatives from diethyl 2-fluoromalonate ester  

PubMed Central

Summary Diethyl 2-fluoromalonate ester is utilised as a building block for the synthesis of 2-fluoro-2-arylacetic acid and fluorooxindole derivatives by a strategy involving nucleophilic aromatic substitution reactions with ortho-fluoronitrobenzene substrates followed by decarboxylation, esterification and reductive cyclisation processes. PMID:24991270

Harsanyi, Antal; Yufit, Dmitri S; Howard, Judith AK

2014-01-01

256

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...

257

Chemically modified fatty acid methyl esters: their potential for use as lubrication fluids and surfactants  

Technology Transfer Automated Retrieval System (TEKTRAN)

A review of recent developments in the synthesis and characterization of lubrication fluids and surfactants from methyl oleate. The synthesis of materials made using an epoxidation route is the focus. This versatile method of chemical modification of fatty acid methyl esters improves their oxidati...

258

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...

259

Chemically Modified Fatty Acid Methyl Esters: Potential as Lubricant and Surfactant  

Technology Transfer Automated Retrieval System (TEKTRAN)

Renewable raw materials are going to play a noteworthy role in the development of sustainable green chemistry because of their eco-friendly and non-toxic nature. A novel process was developed for the production of biodegradable lubricant base stocks from epoxidized fatty acid methyl esters and comm...

260

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...

261

The rates of oxidation of unsaturated fatty acids and esters  

Microsoft Academic Search

Summary  The rates of autoxidation of oleic acid, ethyl oleate, linoleic acid, 10,12-linoleic acid, ethyl linoleate, trilinolein, pentaerythritol\\u000a linoleate, dipentaerythritol linoleate, elaidolinolenic acid, linolenic acid, ethyl linolenate, trilinolenin, and methyl arachidonate\\u000a have been studied by oxygen uptake in a Warburg respirometer and the results are compared with the rates of enzymatic oxidation\\u000a of lipoxidase substrates.\\u000a \\u000a The increase in the number of

Ralph T. Holman; Otto C. Elmer

1947-01-01

262

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

Microsoft Academic Search

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

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

2002-01-01

263

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

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

264

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

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

265

EXTRACTION OF TITANIUM(IV) BY MIXTURES OF MONO AND DH(2-ETHYLHEXYL) PHOSPHORIC ACID ESTERS  

Microsoft Academic Search

Solvent extraction of titanium(IV) from hydrochloric acid solutions by mixtures of mono- and di-2-ethylhexyl phosphoric acid esters (MEHPA and DEHPA) has been investigated as a function of HC1 concentration in the aqueous phase and extractants concentration in the organic phaseIt was found that MEHPA extracts Ti, 3 orders of magnitude more efficiently than DEHPA. Efficiency of extraction by MEHPA does

Vladimir Kislik; Aharon Eyal

1993-01-01

266

Improved separation of conjugated fatty acid methyl esters by silver ion-high-performance liquid chromatography  

Microsoft Academic Search

Operating from one to six silver ion-high-performance liquid chromatography (Ag+-HPLC) columns in series progressively improved the resolution of the methyl esters of conjugated linoleic acid (CLA) isomeric\\u000a mixtures from natural and commercial products. In natural products, the 8 trans, 10 cis-octadecadienoic (18?2) acid was resolved from the more abundant 7 trans, 9 cis-18?2, and the 10 trans, 12 cis-18?2 was

Najibullah Sehat; Rainer Rickert; Magdi M. Mossoba; John K. G. Kramer; Martin P. Yurawecz; John A. G. Roach; Richard O. Adlof; Kim M. Morehouse; Jan Fritsche; Klaus D. Eulitz; Hans Steinhart; Yuoh Ku

1999-01-01

267

Synthesis, Antithrombin and Antituberculous Activity of 2Hydrazino Derivatives of Acylpyruvic Acid Methyl Esters  

Microsoft Academic Search

Acyclic derivatives of substituted 2-hydroxy-4-oxo-2butenoic (acylpyruvic) acids exhibit a broad spectrum of biological activity. Previously, we studied the antimicrobial properties of 2-hydrazino derivatives of acylpyruvic acid methyl esters [1] and established that these substances influence the blood coagulation process [2]. In continuing these investigations, we have synthesized a series of new compounds belonging to this group and studied the antithrombin

S. Yu. Solodnikov; G. D. Miles; O. P. Krasnykh; E. A. Gun; S. A. Naser; N. A. Konyukhova; V. E. Denisov; Yu. I. Shilov

2002-01-01

268

Tribological study of a highly hydrolytically stable phenylboronic acid ester containing benzothiazolyl in mineral oil  

NASA Astrophysics Data System (ADS)

A novel long chain alkyl phenylboronic acid ester containing heterocyclic compound, bis (1-(benzothiazol-2-ylthio) propan-2-yl)-4-dodecylphenylboronic acid ester (DBBMT), was synthesized and characterized. The hydrolytic stability of the DBBMT was evaluated and the results show that DBBMT is of outstanding hydrolytic stability compared with normal borate esters, which indicates that the designed molecular structure, by introducing benzene ring to conjugate with the electron-deficient boron and the benzothiazole as a hinder group, is effective on obtaining a hydrolytically stable long chain alkyl phenylboronic acid ester. The tribological properties of DBBMT and ZDDP in mineral base oil were evaluated using a four-ball tribometer, which suggests that the DBBMT possesses comprehensive tribological properties and could be a potential candidate for the replacement of ZDDP. Furthermore, in order to understand the tribological behaviors, the worn surface was analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) spectroscopy. The results indicate that the elements S, B, O and Fe perform complicated tribochemical reactions to form the compact tribological film composed of B2O3, FeS, Fe3O4 and FeSO4.

Li, Zhipeng; Li, Xiufeng; Zhang, Yawen; Ren, Tianhui; Zhao, Yidong; Zeng, Xiangqiong; van der Heide, E.

2014-07-01

269

Circumvention of defective neutral amino acid transport in Hartnup disease using tryptophan ethyl ester.  

PubMed Central

Tryptophan ethyl ester, a lipid-soluble tryptophan derivative, was used to bypass defective gastrointestinal neutral amino acid transport in a child with Hartnup disease. The child's baseline tryptophan concentrations in serum (20 +/- 6 microM) and cerebrospinal fluid (1.0 +/- 0.2 microM) were persistently less than 50% of normal values. Cerebrospinal fluid 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite, was also less than 50% of normal (21 +/- 2 ng/ml). Serum tryptophan concentrations increased only modestly and briefly after an oral challenge with 200 mg/kg of oral L-tryptophan, reflecting the absorptive defect. An oral challenge with 200 mg/kg of tryptophan ethyl ester resulted in a prompt increase in serum tryptophan to a peak of 555 microM. Sustained treatment with 20 mg/kg q6h resulted in normalization of serum (66 +/- 15 microM) and cerebrospinal fluid tryptophan concentrations (mean = 2.3 microM). Cerebrospinal fluid 5-HIAA increased to more normal concentrations (mean = 33 ng/ml). No toxicity was observed over an 8-mo period of treatment, chronic diarrhea resolved, and body weight, which had remained unchanged for 7 mo before ester therapy, increased by approximately 26%. We concluded that tryptophan ethyl ester is effective at circumventing defective gastrointestinal neutral amino acid transport and may be useful in the treatment of Hartnup disease. PMID:2472426

Jonas, A J; Butler, I J

1989-01-01

270

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

DOEpatents

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.

Moens, Luc (Lakewood, CO)

2003-06-24

271

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2011 CFR

...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...

2011-04-01

272

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2014 CFR

...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...

2014-04-01

273

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

274

21 CFR 172.854 - Polyglycerol esters of fatty acids.  

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

275

Toxicological assessment of 3-chloropropane-1,2-diol and glycidol fatty acid esters in food.  

PubMed

Fatty acid esters of 3-chloropropane-1,2-diol (3-MCPD) and glycidol are a newly identified class of food process contaminants. They are widespread in refined vegetable oils and fats and have been detected in vegetable fat-containing products, including infant formulas. There are no toxicological data available yet on the 3-MCPD and glycidol esters, and the primary toxicological concern is based on the potential release of 3-MCPD or glycidol from the parent esters by lipase-catalyzed hydrolysis in the gastrointestinal tract. Although 3-MCPD is assessed as a nongenotoxic carcinogen with a tolerable daily intake (TDI) of 2??g/kg body weight (bw), glycidol is a known genotoxic carcinogen, which induces tumors in numerous organs of rodents. The initial exposure estimates, conducted by Federal Institute for Risk Assessment (BfR) under the assumption that 100% of the 3-MPCD and glycidol are released from their esters, revealed especially that infants being fed commercial infant formula could ingest harmful amounts of 3-MCPD and glycidol. However, the real oral bioavailability may be lower. As this gives rise for toxicological concern, the currently available toxicological data of 3-MCPD and glycidol and their esters are summarized in this review and discussed with regard to data gaps and further research needs. PMID:21351250

Bakhiya, Nadiya; Abraham, Klaus; Gürtler, Rainer; Appel, Klaus Erich; Lampen, Alfonso

2011-04-01

276

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

E-print Network

molecules in solvent mixtures is not entirely by size exclusion because of partitioning effects and changes in solvation and adsorption. Therefore, changes in solvent composition can affect the separation of solute molecules. Homologous series of n...-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...

Bolton, Patrick Lee

1985-01-01

277

Positional distribution of highly unsaturated fatty acids in triacyl- sn -glycerols of Artemia nauplii enriched with docosahexaenoic acid ethyl ester  

Microsoft Academic Search

This paper presents the positional distribution of fatty acids in triacyl-sn-glycerols (TAG) of Artemia nauplii used in aquaculture as a live food for marine fish larvae. The nauplii were enriched with docosahexaenoic acid (DHA)\\u000a ethyl ester (EE) in the form of gelatin-acacia microcapsules for 4, 18, and 24 h. TAG of the initial, enriched, and unenriched\\u000a Artemia nauplii were subjected

Yasuhiro Ando; Yoshiaki Oomi

2001-01-01

278

A new, direct analytical method using LC-MS/MS for fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD esters) in edible oils.  

PubMed

A new, direct analytical method for the determination of 3-chloro-1,2-propanediol fatty acid esters (3-MCPD esters) was developed. The targeted 3-MCPD esters included five types of monoester and 25 [corrected] types of diester. Samples (oils and fats) were dissolved in a mixture of tert-butyl methyl ether and ethyl acetate (4:1), purified using two solid-phase extraction (SPE) cartridges (C(18) and silica), then analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Five monoesters and five diesters with the same fatty acid group could be separated and quantified. Pairs of 3-MCPD diesters carrying the same two different fatty acid groups, but at reversed positions (sn-1 and sn-2), could not be separated and so were expressed as a sum of both compounds. The limits of quantification (LOQs) were estimated to be between 0.02 to 0.08 mg kg(-1), depending on the types of 3-MCPD ester. Repeatability expressed as relative standard deviation (RSD(r)%) varied from 5.5% to 25.5%. The new method was shown to be applicable to various commercial edible oils and showed levels of 3-MCPD esters varying from 0.58 to 25.35 mg kg(-1). The levels of mono- and diesters ranged from 0.10 to 0.69 mg kg(-1) and from 0.06 to 16 mg kg(-1), respectively. PMID:22909228

Yamazaki, K; Ogiso, M; Isagawa, S; Urushiyama, T; Ukena, T; Kibune, N

2013-01-01

279

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

SciTech Connect

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.

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

1986-11-01

280

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

Microsoft Academic Search

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

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

1950-01-01

281

Quinic acid esters and sesquiterpenes from Sonchus arvensis  

Microsoft Academic Search

A phytochemical study on the whole plant of Sonchus arvensis and its antioxidant activity has been carried out. Three quinic acid derivatives (1–3), the rarely naturally occurring (p-hydroxyphenylacetyl) quinic acids, and two eudesmanolides (4 and 5) were newly found. Four known eudesmanolides (6–9) were isolated from the plant for the first time. Their structures were characterized by HRESIMS, IR, UV,

Yang-Jun Xu; Shao-Bo Sun; Li-Mei Sun; Dong-Feng Qiu; Xiu-Jin Liu; Zhi-Bo Jiang; Cheng-Shan Yuan

2008-01-01

282

Enzymatic esterification of tapioca maltodextrin fatty acid ester.  

PubMed

In this work new types of hydrophobically modified maltodextrin were prepared by enzyme-catalyzed reaction of maltodextrin and three fatty acids: decanoic acid (C-10), lauric acid (C-12) and palmitic acid (C-16). Lipase obtained from Thermomyces lanuginosus was found to be a useful biocatalyst in the maltodextrin esterification. Esterified maltodextrin with a degree of substitution (DS) 0.015-0.084 was prepared at the optimum conditions of 60 °C for 4 h. The DS was found to be at its highest when maltodextrin and fatty acids were taken in the ratio 1:0.5. The functional properties of these esterified maltodextrin were investigated. All esterified maltodextrin did not completely dissolve in water. Esterified maltodextrin at a concentration of 25% (w/w) exhibited Newtonian flow behavior similar to that of native maltodextrin. Esterified maltodextrin had a higher viscosity compare to native maltodextrin. X-ray diffraction pattern of esterified maltodextrin indicated crystallization of the fatty acid side chains. The thermal stability of esterified maltodextrin was checked by differential scanning calorimetry (DSC). Esterified maltodextrin was then used as an emulsifier to make n-hexadecane O/W emulsions. The emulsions were characterized according to their oil droplet characteristics and emulsification index. PMID:24274521

Udomrati, Sunsanee; Gohtani, Shoichi

2014-01-01

283

The adjuvant activity of fatty acid esters. The role of acyl chain length and degree of saturation.  

PubMed Central

Water-in-oil emulsions of metabolizable fatty acid esters, with the non-toxic surfactant Pluronic L122 as emulsifying agent, potentiated the humoral response to bovine serum albumin and staphylococcal toxoid in the mouse. Adjuvant activity was increased by changing the chemical nature of the esters as follows: (i) using a series of ethyl esters, adjuvant activity appeared when the acyl chain length of the fatty acid component was 16 or greater; (ii) isobutyl and isopropyl esters of palmitic acid (C16:0) were superior to ethyl; (iii) the ethyl esters of oleic (C18:1) and linoleic (C18:2) acids were better than stearic (C18:0). Since emulsions prepared with longer chain saturated esters are very viscous or solid at room temperature, and unsaturated esters are chemically reactive, emulsions were prepared with differing proportions of ethyl caprate (C10:0) and butyl stearate. At a ratio of 9:1 the emulsions possessed the low viscosity of ethyl caprate, but gained the adjuvant activity of butyl stearate. 125I-labelled BSA was retained in the footpad to a significantly greater extent than with a caprate emulsion, but reasons are given for believing that slow release of antigen is not the only mechanism of adjuvant activity. The ester emulsions caused more acute but less chronic local inflammation (footpad swelling) than Freund's incomplete adjuvant. PMID:7275184

Bomford, R

1981-01-01

284

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

PubMed

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

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

2015-02-01

285

Allylic oxidation of ent-Kaurenic acid, ent-Kaurenic acid Methyl Ester and ent-Kaurenol  

Microsoft Academic Search

The allylic oxidation of ent-kaurenic acid, ent-kaurenic acid methyl ester, and ent-kaurenol with SeO2\\/H2O2 is presented. The reaction was run in dioxan solution at room temperature stirring for 4 hours. About 0.3 mmol of substrate was treated with 1.2 mmol of SeO2 and 4.1 mmol of H2O2. Treatment of ent-kaurenic acid afforded 56% of ent-15?-hydroxy-kaur-16-en-19-oic acid (2a). Treatment of ent-kaurenic

Rosa Aparicio; Ali Bahsas; Alfredo Usubillaga

2007-01-01

286

Paper chromatography of phospholipides on silicic acid impregnated glass fiber filter paper  

Microsoft Academic Search

Summary  1. A reasonably reproducible method has been developed for separating lysolecithin, lecithin,, sphingomyelin, and phosphatidylethanolamine,\\u000a using glass fiber filter paper impregnated with silicic acid as the chromatographic medium and 1:1 methanol:ethyl ether as\\u000a the developing solvent.\\u000a \\u000a 2. Hot sulfuric acid was used to locate the chromatographed compounds on the chromatogram. The advantages and disadvantages\\u000a of this reagent and the other

Julius W. Dieckert; Raymond Reiser

1956-01-01

287

Miniemulsion as efficient system for enzymatic synthesis of acid alkyl esters.  

PubMed

The aim of this work is to devise an efficient enzymatic process for the production of linear alkyl esters in aqueous miniemulsion systems. The esterification reactions of linear alcohols and carboxylic acids were performed with three different enzymes, commercial Amano lipase PS from Pseudomonas cepacia, Lipase type VII from Candida rugosa, and lyophilized Fusarium solani pisi cutinase expressed in Saccharomyces cerevisiae SU50. The miniemulsion system shows a high potential for the synthesis of linear alkyl esters, for example, hexyl octanoate, which could be synthesized with an ester yield of 94% using Amano lipase PS. Even with hydrophilic alcohols as ethanol, ethyl decanoate could be obtained with a concentration of 0.45 M and a yield of 62% using F. s. pisi cutinase as catalyst. High esterification rates for ethyl- and hexyloleate in miniemulsion showed a significant shift in cutinase selectivity towards longer chain length carboxylic acids. The stepwise addition of the alcohol led to an increase of the esterification yield. Moreover, increasing the amount of dispersed organic phase, mainly consisting of the substrates, led to a significant increase of the final ester concentration (e.g., concentration of 1.4 M for ethyl decanoate for the esterification with Amano Lipase PS). PMID:20503297

de Barros, Dragana P C; Fonseca, Luís P; Cabral, Joaquim M S; Aschenbrenner, Eugen M; Weiss, Clemens K; Landfester, Katharina

2010-07-01

288

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

SciTech Connect

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)

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

289

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)

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.

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

1985-01-01

290

Preparation of silicate tungsten bronzes on aluminum by plasma electrolytic oxidation process in 12-tungstosilicic acid  

NASA Astrophysics Data System (ADS)

The growth of silicate tungsten bronzes on aluminum by plasma electrolytic oxidation in 12-tungstosilicic acid is experimentally investigated and discussed. Real time imaging and optical emission spectroscopy characterization of plasma electrolytic oxidation show that spatial density of microdischarges is the highest in the early stage of the process, while the percentage of oxide coating area covered by active discharge sites decreases slowly with time. Emission spectrum of microdischarges has several intensive band peaks originating either from aluminum electrode or from the electrolyte. Surface roughness of obtained oxide coatings increases with prolonged time of plasma electrolytic oxidation, as their microhardness decreases. Raman spectroscopy and energy dispersive X-ray spectroscopy are employed to confirm that the outer layer of oxide coatings formed during the plasma electrolytic oxidation process is silicate tungsten bronze

Petkovi?, M.; Stojadinovi?, S.; Vasili?, R.; Bel?a, I.; Nedi?, Z.; Kasalica, B.; Mio?, U. B.

2011-09-01

291

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

PubMed Central

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

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

2014-01-01

292

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

PubMed

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

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

2014-01-01

293

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 ...

294

Calculations of phase equilibria for mixtures of triglycerides, fatty acids, and their esters in lower alcohols  

NASA Astrophysics Data System (ADS)

The objects of study were mixtures containing triglycerides and lower alcohols and also the products of the transesterification of triglycerides, glycerol and fatty acid esters. The Redlich-Kwong-Soave equation of state was used as a thermodynamic model for the phase state of the selected mixtures over wide temperature, pressure, and composition ranges. Group methods were applied to determine the critical parameters of pure substances and their acentric factors. The parameters obtained were used to calculate the phase diagrams and critical parameters of mixtures containing triglycerides and lower alcohols and the products of the transesterification of triglycerides, glycerol and fatty acid esters, at various alcohol/oil ratios. The conditions of triglyceride transesterification in various lower alcohols providing the supercritical state of reaction mixtures were selected.

Stepanov, D. A.; Ermakova, A.; Anikeev, V. I.

2011-01-01

295

Development of efficient Lewis acid catalysts for intramolecular cycloaddition reactions of ester-tethered substrates.  

PubMed

We have developed novel bidentate Lewis acids that efficiently promote the intramolecular cycloaddition reactions of ester-tethered substrates. Bis-aluminated triflic amide derivatives [TfN(AlR(1)R(2))2], which are generated by simply mixing triflic amide and 2 equiv of methyl aluminum or aluminum hydride, catalyzed intramolecular Diels-Alder (DA) reactions of ester-tethered 1,7,9-trienes and intermolecular DA reactions of alpha,beta-unsaturated lactones. We also found that bimetallic Lewis acid derived from 1,1'-biphenyl-2,2'-di(triflyl)amide and dimethylaluminum chloride promoted the intramolecular [3 + 2] cycloaddition reaction of acrylate derivatives having an allylsilane part. PMID:17549689

Taguchi, Takeo; Saito, Akio; Yanai, Hikaru

2007-01-01

296

Sterol fatty acid esters from the mushroom Hericium erinaceum and their PPAR transactivational effects.  

PubMed

Six new (erinarols A-F, 1-6) and five known (7-11) ergostane-type sterol fatty acid esters were isolated from the methanol extract of the dried fruiting bodies of Hericium erinaceum. Their chemical structures were elucidated using chemical and physical methods as well as through comparison of NMR and mass spectral data with those reported previously. This is the first comprehensive investigation on ergostane-type sterol fatty acid esters from H. erinaceum. The isolated compounds were evaluated for their PPAR transactivational effects using a luciferase reporter system. Compounds 1 and 2 significantly activated the transcriptional activity of PPARs in a dose-dependent manner, with EC50 values of 8.2 and 6.4 ?M, respectively. Moreover, compounds 1 and 2 also activated PPAR? and PPAR? transcriptional activity, with stimulation from 1.3- to 3.9-fold at 20 ?M concentrations. PMID:25437304

Li, Wei; Zhou, Wei; Song, Seok Bean; Shim, Sang Hee; Kim, Young Ho

2014-12-26

297

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

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

298

Evaluation of eye irritation by S-(-)-10,11-dihydroxyfarnesic acid methyl ester secreted by Beauveria bassiana CS1029  

PubMed Central

The aim of this study was to investigate whether S-(-)-10,11-dihydroxyfarnesic acid methyl ester produced by cell subtype Beauveria bassiana CS1029 causes acute toxicity when used for cosmetic purposes by performing an eye irritation test. New Zealand white (NZW) rabbits were treated with a 100 mg/dose of S-(-)-10,11-dihydroxyfarnesic acid methyl ester according to standard procedure guidelines. No significant changes in terms of ocular lesions of the cornea, turbidity of the cornea, swelling of the eyelid or ocular discharge were observed in the methyl ester-treated groups, while sodium dioctyl sulfosuccinate, a positive control, caused severe toxicity. The anatomical and pathological observations indicate that the methyl ester produced by Beauveria bassiana CS1029 did not induce eye irritation in the lenses of the rabbits. The data suggest that the methyl ester evaluated in this study has promising potential as a cosmetic ingredient that does not irritate the eye. PMID:24137288

SON, HYEONG-U; LEE, SANG-HAN

2013-01-01

299

Evaluation of eye irritation by S-(-)-10,11-dihydroxyfarnesic acid methyl ester secreted by Beauveria bassiana CS1029.  

PubMed

The aim of this study was to investigate whether S-(-)-10,11-dihydroxyfarnesic acid methyl ester produced by cell subtype Beauveria bassiana CS1029 causes acute toxicity when used for cosmetic purposes by performing an eye irritation test. New Zealand white (NZW) rabbits were treated with a 100 mg/dose of S-(-)-10,11-dihydroxyfarnesic acid methyl ester according to standard procedure guidelines. No significant changes in terms of ocular lesions of the cornea, turbidity of the cornea, swelling of the eyelid or ocular discharge were observed in the methyl ester-treated groups, while sodium dioctyl sulfosuccinate, a positive control, caused severe toxicity. The anatomical and pathological observations indicate that the methyl ester produced by Beauveria bassiana CS1029 did not induce eye irritation in the lenses of the rabbits. The data suggest that the methyl ester evaluated in this study has promising potential as a cosmetic ingredient that does not irritate the eye. PMID:24137288

Son, Hyeong-U; Lee, Sang-Han

2013-10-01

300

Separation of Ethyl Ester of Docosahexaenoic Acid by Facilitated Transport Membrane with High Stability  

Microsoft Academic Search

The selective transport of the ethyl ester of docosahexaenoic acid (DHA-Et) was studied in the facilitated transport system where feed phase, membrane phase, and receiving phase had the same ethanol diluent. The carrier of DHA-Et was Ag, and a Nafion membrane was used as the support so that Ag was immobilized in the support by electrostatic force. DHA-Et was sufficiently

YOSHIRO KITAMURA; HIDETO MATSUYAMA; AKIHIRO NAKABUCHI; NOBUHIRO MATSUI; YUJI DOI; YORISHIGE MATSUBA

1999-01-01

301

Oxidative stability and storage behavior of fatty acid methyl esters derived from used palm oil  

Microsoft Academic Search

Fatty acid alkyl esters, especially FAME, are the most commonly used liquid biofuel. Because biofuels are expected to be important\\u000a alternative renewable energy sources in the near future, more studies on their stability against oxidation need to be addressed.\\u000a Biofuel derived from vegetable oils is well researched, currently with more attention focused on the reuse of waste oil sources\\u000a than

Soh-Kheang Loh; Soo-Mooi Chew; Yuen-May Choo

2006-01-01

302

Control of the phytopathogen Botrytis cinerea using adipic acid monoethyl ester  

Microsoft Academic Search

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

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

303

Solutol HS 15, Nontoxic Polyoxyethylene Esters of 12-Hydroxystearic Acid, Reverses Multidrug Resistance1  

Microsoft Academic Search

A recently developed non-ionic surfactant called Solutol IIS 15 (poly- oxyethylene esters of 12-hydroxystearic acid), with low toxicity in vivo, was shown to reverse completely the multidrug resistance of KB 8-5 and KB 8-5-11 human epidermoid carcinoma cells in vitro but did not potentiate drug toxicity in drug-sensitive KB3-1 cells. At a concentration of 10% of its own ICso (mean

John S. Coon; Warren Knudson; Kathleen Clodfelter; Bing Lu; Ronald S. Weinstein

304

Fatty acid esters of 3-chloropropane-1,2-diol in edible oils  

Microsoft Academic Search

A series of 25 virgin and refined edible oils, obtained from retailers, was analyzed for levels of free 3-chloropropane-1,2-diol (3-MCPD) and 3-MCPD released from esters with higher fatty acids (bound 3-MCPD). Oils containing free 3-MCPD ranging from <3?µg?kg (LOD) to 24?µg?kg. Surprisingly, bound 3-MCPD levels were much higher and varied between <100 (LOD) and 2462?µg?kg. On average, virgin oils had

Z. Zelinková; B. Svejkovská; J. Velíšek; M. Doležal

2006-01-01

305

Decarboxylative allylation of amino alkanoic acids and esters via dual catalysis.  

PubMed

A combination of photoredox and palladium catalysis has been employed to facilitate the room temperature decarboxylative allylation of recalcitrant ?-amino and phenylacetic allyl esters. This operationally simple process produces CO2 as the only byproduct and provides direct access to allylated alkanes. After photochemical oxidation, the carboxylate undergoes radical decarboxylation to site-specifically generate radical intermediates which undergo allylation. A radical dual catalysis mechanism is proposed. Free phenylacetic acids were also allylated utilizing similar reactions conditions. PMID:25228064

Lang, Simon B; O'Nele, Kathryn M; Tunge, Jon A

2014-10-01

306

Kinetics of the reduction of p-nitrobenzoic acid esters in nanoreactors on the basis of sulfonated polymers  

NASA Astrophysics Data System (ADS)

The kinetics of the reduction of p-nitrobenzoic acid esters in nanoreactors based on sulfonated network polymers containing nanodispersed palladium was studied. The kinetic characteristics of the hydrogenation of aromatic nitro compounds were calculated.

Al'tshuler, G. N.; Shkurenko, G. Yu.; Gorlov, A. A.

2015-03-01

307

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2013 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.225 Methyl and ethyl esters of fatty acids produced from edible fats and oils....

2013-04-01

308

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2011 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.225 Methyl and ethyl esters of fatty acids produced from edible fats and oils....

2011-04-01

309

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2012 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.225 Methyl and ethyl esters of fatty acids produced from edible fats and oils....

2012-04-01

310

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2010 CFR

...FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.225 Methyl and ethyl esters of fatty acids produced from edible fats and oils....

2010-04-01

311

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2014 CFR

...HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.225 Methyl and ethyl esters of fatty acids produced from edible fats and oils....

2014-04-01

312

SMECTIC F TRENDS IN THE 4-(2'-METHYLBUTYL)PHENYL ESTERS OF 4 -n-ALKOXYBIPHENYL-4-CARBOXYLIC ACIDS AND  

E-print Network

that the trend in the SC-SF transition temperatures for these esters is unaffected by the small changes acids were esterified with racemic 4-(2'- methylbutyl)phenol. The general structure for these esters

Paris-Sud XI, Université de

313

Regiospecific distribution of fatty acids in triacylglycerols of Artemia franciscana nauplii enriched with fatty acid ethyl esters  

Microsoft Academic Search

This paper reports the positional distribution of fatty acids in triacylglycerols (TAG) of Artemia franciscana nauplii enriched with each of palmitic (16:0), oleic (18:1n-9), linoleic (18:2n-6), linolenic (18:3n-3), eicosapentaenoic (20:5n-3), and docosahexaenoic (22:6n-3) acid ethyl esters. TAG extracted from the enriched and unenriched nauplii were subjected to regiospecific analysis to determine the fatty acid compositions of the sn-1(3) and sn-2

Yasuhiro Ando; Yoshiaki Oomi; Keiichi Narukawa

2002-01-01

314

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

NASA Astrophysics Data System (ADS)

The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3?HCOOC2H5, -CH2?HCOOH and -CH2?HCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed.

Ba?kan, M. Halim; Ayd?n, Murat

2013-08-01

315

The isolation of omega-3 polyunsaturated fatty acids and methyl esters of fish oils by silver resin chromatography  

Microsoft Academic Search

Multigram quantities of the highly unsaturated ?3 component from samples of fish oil fatty acids and esters were isolated\\u000a by silver resin chromatography. An XN1010 resin column saturated with silver ions was utilized. Polyunsaturated fatty acid\\u000a (PUFA) esters from fish oil concentrate (FOC) were fractionated based on the number of double bonds by using solvent programming\\u000a (acetonitrile in methanol). Larger

R. O. Adlof; E. A. Emken

1985-01-01

316

Optical properties of conjugated poly(3-hexylthiophene)\\/[6,6]-phenylC61-butyric acid methyl ester composites  

Microsoft Academic Search

In this work, we present the evolution of optical constants as a function of [6,6]-phenyl C61-butyric acid methyl ester (PCBM) concentration for conjugated poly(3-hexylthiophene)\\/[6,6]-phenylC61-butyric acid methyl ester composites. The PCBM concentration of the utilized samples varies from 1 to 50 wt %. The dielectric functions for all these composites reveal electronic structural changes as a result of the addition of

Emmanouil Lioudakis; Andreas Othonos; Ioannis Alexandrou; Yasuhiko Hayashi

2007-01-01

317

Polymerization of drying oils. VI. Catalytic polymerization of fatty acids and esters with boron trifluoride and hydrogen fluoride  

Microsoft Academic Search

Summary  At relatively low temperatures boron trifluoride and hydrogen fluoride gave high yields of polymers from soybean fatty acids\\u000a and methyl esters.\\u000a \\u000a The use of 2% boron trifluoride as catalyst at 150 to 200 resulted in the polymerization of 50–60% of the methyl esters\\u000a within one hour. The viscous polymeric fraction usually had a dark color, a high acid number, and

C. B. Croston; I. L. Tubb; J. C. Cowan; H. M. Teeter

1952-01-01

318

An Efficient Method for Determination of the Degree of Substitution of Cellulose Esters of Long Chain Aliphatic Acids  

Microsoft Academic Search

The determination of the degree of substitution (DS) of fatty acid cellulose esters, representing a broad range of substituents (C6, C12, C18 and C22), was performed by alkaline hydrolysis of the ester groups and the quantification of fatty acids by gas chromatography-mass spectrometry (GC-MS) as their trimethylsilyl derivatives. The method was optimized and compared with established techniques for the DS

C. S. R. Freire; A. J. D. Silvestre; C. Pascoal Neto; R. M. A. Rocha

2005-01-01

319

Caffeic acid phenethyl ester prevents apoptotic cell death in the developing rat brain after pentylenetetrazole-induced status epilepticus.  

PubMed

Population-based studies suggest that seizure incidence is highest during the first year of life, and early-life seizures frequently result in the development of epilepsy and behavioral alterations later in life. The early-life insults like status epilepticus often lead to epileptogenesis, a process in which initial brain injury triggers cascades of molecular, cellular, and network changes and eventually spontaneous seizures. Caffeic acid phenethyl ester is an active component of propolis obtained from honeybees and has neuroprotective properties. The aim of this study was to investigate whether caffeic acid phenethyl ester exerts neuroprotective effects on the developing rat brain after status epilepticus. Twenty-one dams reared Wistar male rats, and 21-day-old rats were divided into three groups: control group, pentylenetetrazole-induced status epilepticus group, and caffeic acid phenethyl ester-treated group. Status epilepticus was induced on the first day of experiment. Caffeic acid phenethyl ester injections (30 mg/kg intraperitoneally) started 40 min after the tonic phase of status epilepticus was reached, and the injections of caffeic acid phenethyl ester were repeated over 5 days. Rats were sacrificed, and brain tissues were collected on the 5th day of experiment after the last injection of caffeic acid phenethyl ester. Apoptotic cell death was evaluated. Histopathological examination showed that caffeic acid phenethyl ester significantly preserved the number of neurons in the CA1, CA3, and dentate gyrus regions of the hippocampus and the prefrontal cortex. It also diminished apoptosis in the hippocampus and the prefrontal cortex. In conclusion, this experimental study suggests that caffeic acid phenethyl ester administration may be neuroprotective in status epilepticus in the developing rat brain. PMID:24012504

Yi?, Uluç; Topçu, Yasemin; Özbal, Seda; Tu?yan, Kaz?m; Bayram, Erhan; Karakaya, Pakize; Yilmaz, Osman; Kurul, Semra H?z

2013-11-01

320

The synthesis, properties, and applications of hydrophilic polymers and copolymers of hydroxyalkyl esters of acrylic and methacrylic acids  

NASA Astrophysics Data System (ADS)

The scientific-technical and patent literature on the synthesis of hydroxyalkyl esters of acrylic and methacrylic acids by their catalytic reaction with epoxyalkanes, by the radical copolymerisation and polymerisation of presynthesised monomeric esters, and also by the chemical modification of polymerisation and copolymerisation products is surveyed. A wide variety of physicochemical properties of the polymers and copolymers based on the hydroxyalkyl esters of acrylic and methacrylic acids are described. The principal trends and prospects in the application of the high-molecular-weight products obtained in various branches of the national economy are indicated. The bibliography includes 158 references.

Asadov, Z. G.; Aliev, V. S.

1992-05-01

321

Formation of Toxic ?,?-Unsaturated 4-Hydroxy-Aldehydes in Thermally Oxidized Fatty Acid Methyl Esters  

Microsoft Academic Search

To investigate the heat induced formation of ?,?-unsaturated 4-hydroxy-aldehydes (4-hydroxy-2-trans-hexenal (HHE), 4-hydroxy-2-trans-octenal (HOE), 4-hydroxy-2-trans-nonenal (HNE) and 4-hydroxy-2-trans-decenal (HDE)) fatty acid methyl esters (FAMEs) of stearic, oleic, linoleic and linolenic acids were heated separately at\\u000a 185°C for 0 to 6 hrs. The formation of 2,4-decadienal, a suspected intermediate in HNE formation, was also measured in these\\u000a FAMEs. As expected methyl stearate

In Hwa Han; A. Saari Csallany

2009-01-01

322

Enzymatic synthesis of hydrophilic undecylenic acid sugar esters and their biodegradability.  

PubMed

To enhance water solubility of 10-undecylenic acid, which has anti-fungus, anti-bacterial and anti-virus activity, D-glucose, trehalose and sucrose were regioselectively esterified with vinyl 10-undecylenic acid ester in dimethyl formamide by a commercial protease, Bioprase conc., from Bacillus subtilis. 6-O-(10-Undecylenoyl) D-glucose, 6-O-(10-undecylenoyl) trehalose and 1'-O-(10-undecylenoyl) sucrose were obtained. The influence of structural variation by changing the sugar moiety was analyzed the surface tension and biodegradability. PMID:12882293

Raku, Takao; Kitagawa, Masaru; Shimakawa, Hiromi; Tokiwa, Yutaka

2003-01-01

323

A new CO 2 disposal process via artificial weathering of calcium silicate accelerated by acetic acid  

Microsoft Academic Search

A new disposal process for anthropogenic CO2 via an artificially accelerated weathering reaction is proposed to counteract global warming. The process is essentially composed of the following two steps:(1)CaSiO3+2CH3COOH?Ca2++2CH3COO?+H2O+SiO2(2)Ca2++2CH3COO?+CO2+H2O?CaCO3?+2CH3COOHStep (1) is the extraction of calcium ions by acetic acid from calcium silicate, for example, wollastonite rocks. Step (2) is the deposition of calcium carbonate from the solution of calcium ions

M. Kakizawa; A. Yamasaki; Y. Yanagisawa

2001-01-01

324

Substituent effect on the formation of organically-modified silicate-phosphate alternating copolymer through nonaqueous acid–base reaction  

Microsoft Academic Search

Organically-modified silicate-phosphate and silicate-phosphite copolymers were prepared through nonaqueous acid–base reaction.\\u000a The inductive effect of the organic substituent of the starting materials such as organically-modified chlorosilane and phosphorous\\u000a acid on the acid–base reaction was investigated by 31P NMR measurement and ab initio molecular orbital calculation. The condensation reaction takes place by nucleophilic addition\\u000a of phosphate ion (or phosphite ion) to

Megumi Mizuno; Masahide Takahashi; Yomei Tokuda; Toshinobu Yoko

2007-01-01

325

Catalytic, Enantioselective Alkylation of r-Imino Esters: The Synthesis of Nonnatural r-Amino Acid Derivatives  

E-print Network

Catalytic, Enantioselective Alkylation of r-Imino Esters: The Synthesis of Nonnatural r-Amino Acid, 2001 Abstract: Methodology for the practical synthesis of nonnatural amino acids has been developed (up to 25:1/anti:syn), are protected nonnatural amino acids that represent potential precursors

Lectka, Thomas

326

Nervonic acid versus tricosanoic acid as internal standards in quantitative gas chromatographic analyses of fish oil longer-chain n-3 polyunsaturated fatty acid methyl esters.  

PubMed

Tricosanoic acid (23:0) and cis-15-tetracosenoic acid (nervonic acid, 24:1 n-9) were compared as choices suitable for use as internal standards in the quantitation of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids. Experiments conducted included: (a) comparison of the flame ionisation detector responses of the two fatty acid methyl esters; (b) estimation of accurately weighed quantities of EPA and DHA using both 23:0 and 24:1 separately as internal standard; (c) determination of EPA and DHA contents of commercially available fish oil ethyl ester capsules using the two as internal standard. The results suggest that both 23:0 and 24:1 methyl esters behaved similarly in the flame ionization detector of the gas chromatograph and are comparable internal standards for use in quantitation of EPA and DHA. This includes the analysis of ethyl ester mixtures as long as interesterification of sample with solvent methanol is complete. The relatively poor solubility of the saturated 23:0 is countered by its greater stability. A possible drawback of 24:1 could be the presence of more than one positional isomer in either a 24:1n-9 standard or in the actual sample. In principle any fatty acid could serve as an internal standard as long as the limitations involved in the use of each are taken into account. PMID:2150519

Shantha, N C; Ackman, R G

1990-11-30

327

Novel surface lipids of diapausing Manduca sexta pupae. Long chain oxoalcohol esters of acetoacetic, hydroxybutyric, and acetic acids.  

PubMed

Ester components in the surface wax from diapausing tobacco hornworm pupae, Manduca sexta L., were separated by thin layer chromatography and gas-liquid chromatography, and characterized by infrared spectroscopy and gas-liquid chromatography-mass spectrometry. Three groups of esters were identified as natural derivatives of acetic acid, acetoacetic acid, and 3-hydroxybutyric acid. The major ester fraction was identified as a mixture of C26 (10%), C27 (5%), and C28 (85%) oxoalcohol esters of acetoacetic acid. The major homolog consisted of equal amounts of 11-oxooctacosanyl 3-oxobutanoate and 12-oxooctacosanyl 3-oxobutanoate. Lesser amounts of 11- and 12-oxooctacosanyl and n-octacosanyl esters of acetic and 3-hydroxybutyric acids were also identified. The chain length distributions of these C26, C27, and C28 oxoalcohol and n-primary alcohol ester moieties, as well as the isomeric ratios for the 11- and 12-oxoalcohol isomers, were similar to the oxoaldehydes and unesterified oxoalcohols previously identified by Buckner et al (Buckner, J. S., Nelson, D. R., Haak, H., and Pomonis, J. G. (1984) J. Biol. Chem. 259, 8452-8470) as lipid components of the surface wax of M. sexta pupae. PMID:6736039

Buckner, J S; Nelson, D R; Fatland, C L; Hakk, H; Pomonis, J G

1984-07-10

328

Studies of the acidic components of the Colorado Green River formation oil shale-Mass spectrometric identification of the methyl esters of extractable acids.  

NASA Technical Reports Server (NTRS)

Study of solvent extractable acidic constituents of oil shale from the Colorado Green River Formation. Identification of individual components is based on gas chromatographic and mass spectrometric data obtained for their respective methyl esters. Normal acids, isoprenoidal acids, alpha, omega-dicarboxylic acids, mono-alpha-methyl dicarboxylic acids and methyl ketoacids were identified. In addition, the presence of monocyclic, benzoic, phenylalkanoic and naphthyl-carboxylic acids, as well as cycloaromatic acids, is demonstrated by partial identification.

Haug, P.; Schnoes, H. K.; Burlingame, A. L.

1971-01-01

329

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

PubMed

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 a significant decrease on the total lipids, specially on phospholipids, both in total liver and microsomes. (14C-2,4-D) subcellular distribution in liver demonstrated that the herbicide passed through the plasmatic membrane and it was present in all the studied fractions. Herbicide bound covalently to hepatic proteins and lipids, being the binding to proteins tenfold higher than to lipids. Because these results might be of potential relevance to the understanding of the 2,4-D toxicity, further studies on the mechanisms of these reactions are necessary. On the other hand, the microsomal and cytosolic glutathione S-transferases activities remained unchanged, even though in vitro studies 2,4-D ester caused a decrease of the enzyme activities with an I50 value of 0.2 mM. No significant change in reduced glutathione content between control and treated livers was observed. The catalase activity increased two-fold whereas glucose 6-phosphatase activity decreased 46% with respect to the corresponding control values. These results indicate that 2,4-D ester may have effects on the metabolism of xenobiotics. PMID:8368864

Evangelista de Duffard, A M; Fabra de Peretti, A; Castro de Cantarini, S; Duffard, R

1993-08-01

330

In vivo degradation and elimination of injectable ricinoleic acid-based poly(ester-anhydride).  

PubMed

The in vivo degradation and elimination after subcutaneous implantation of injectable p(SA-RA) 3:7 copolymer in rats, followed by characterization of the polymer matrix composition during hydrolysis and erosion, is reported. Major chemical changes were observed during the first few days post implantation, the anhydride bonds hydrolyzed along with about 45% weight loss and a significant decrease in the molecular weight. 1H NMR spectral analysis was used to determine the structures and content of ricinoleic acid containing oligomeric chains present in the degraded polymer. The polymer degrades into ester oligomers of 2-4 ricinoleic acid units which further degrade to ricinoleic acid, a natural fatty acid. The polymer hydrolytic degradation process fit the in vitro degradation process. PMID:23530926

Vaisman, Boris; Ickowicz, Diana E; Abtew, Ester; Haim-Zada, Moran; Shikanov, Ariella; Domb, Abraham J

2013-05-13

331

Features of separation on polymeric reversed phase for two classes of higher saturated fatty acids esters  

NASA Astrophysics Data System (ADS)

The principles of sorption on polymeric reversed phase (PRP) YMS C30 for members of the two classes of esters formed by higher saturated fatty acids, i.e., lutein diesters ( I) and triacylglycerols ( II), are investigated. It is shown that the logarithm of the retention factor increases nonlinearly with an increase of the length of the acid radical, although the retention on PRP is higher in the case of I and lower in the case of II, compared to their retention on traditional monomeric reversed phase (MRP) Kromasil-100 5C18; however, the equivalence of the contributions to the retention of I that correspond to an identical change in acids, does not depend on the length of the hydrocarbon radical of the second acid. It is noted that the Van't Hoff plot for PRP contains a curve break, indicating a change in the retention mechanism upon a rise in temperature.

Deineka, V. I.; Lapshova, M. S.; Zakharenko, E. V.; Deineka, L. A.

2013-11-01

332

Characterization of benthic microbial community structure by high-resolution gas chromatography of fatty acid methyl esters  

SciTech Connect

Fatty acids are a widely studied group of lipids of sufficient taxonomic diversity to be useful in defining microbial community structure. 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. 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 C/sub 18/ dienoic and the C/sub 18/ and C/sub 20/ 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 C/sub 15/ fatty acid esters, C/sub 17/ cyclopropane fatty acid esters, and the cisvaccenic isomer of the C/sub 18/ 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.

Bobbie, R.J.; White, D.C.

1980-06-01

333

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

PubMed

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

Li, Yizhe; Bao, Guirong; Wang, Hua

2008-07-01

334

Surface site density, silicic acid retention and transport properties of compacted magnetite powder  

NASA Astrophysics Data System (ADS)

In France, within the framework of investigations of the feasibility of deep geological disposal of high-level radioactive waste, studies on corrosion products of steel over packs are ongoing. Such studies concern silica and radionuclide retention. The objective of the present work is to study sorption of silicic acid on compacted magnetite in percolation cells to attempt to simulate confined site conditions. Potentiometric titration of commercial magnetite was carried out with both dispersed and compacted magnetite. The titration of the magnetite suspension has been made with two different methods: a batch method (several suspensions) and a direct fast method (one suspension). The Gran’s function gave 1.7 (±0.4) and 2.4 (±0.5) sorption sites nm -2 with these respective methods but site densities as high as 20/nm 2 could be obtained by modelling. The titration of magnetite compacted at 120 bars showed that the evolution of charge density on magnetite surfaces is similar for compacted and dispersed magnetite. Silicic acid sorption onto dispersed and compacted magnetite was similar with sorption site densities ranging between 2.2 and 4.4/nm 2.

Mayant, C.; Grambow, B.; Abdelouas, A.; Ribet, S.; Leclercq, S.

335

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

PubMed

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

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

2014-01-01

336

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

PubMed

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

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

2011-06-01

337

40 CFR 721.10289 - Hexanedioic acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic).  

Code of Federal Regulations, 2012 CFR

...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). 721...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). (a...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (PMN...

2012-07-01

338

40 CFR 721.10289 - Hexanedioic acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic).  

Code of Federal Regulations, 2014 CFR

...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). 721...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). (a...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (PMN...

2014-07-01

339

40 CFR 721.10289 - Hexanedioic acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic).  

Code of Federal Regulations, 2013 CFR

...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). 721...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). (a...polymer with aliphatic polyol dihydrogen phosphate aromatic ester (PMN...

2013-07-01

340

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

PubMed

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

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

2008-05-01

341

Development of biodegradable flexible films of starch and poly(lactic acid) plasticized with adipate or citrate esters.  

PubMed

Biodegradable films were produced from blends contained a high amount of thermoplastic starch (TPS) and poly(lactic acid) (PLA) plasticized with different adipate or citrate esters. It was not possible to obtain pellets for the production of films using only glycerol as a plasticizer. The plasticization of the PLA with the esters and mixture stages added through extrusion was critical to achieve a blend capable of producing films by blow extrusion. Adipate esters were the most effective plasticizers because they interacted best with the PLA and yielded films with appropriate mechanical properties. PMID:23218260

Shirai, M A; Grossmann, M V E; Mali, S; Yamashita, F; Garcia, P S; Müller, C M O

2013-01-30

342

An increase in cholesterol ester content of the rat aorta by a high fat-high erucic acid diet.  

PubMed

Rats of weaning age were feed for a period of 1 or 3 weeks either a low fat diet (laboratory stock diet) or a semi-synthetic diet containing 20% by weight of either corn oil (2/3 of the total fatty acids consisted of linoleic acid) or mustard seed oil (1/3 of the total fatty acids were comprised of erucic acid). Feeding of a diet rich in erucic acid for 1 week increased by twofold the cholesterol ester content of the aorta. However, the concentrations of unesterified cholesterol and individual phospholipids in the aorta were uninfluenced by hyperlipemia induced by this diet. Fatty acid analyses indicated that erucic (22:1) and eicosenoic (20:1) acids are found in the triglyceride and cholesterol esters of the aorta in the proportion similar to that found in the plasma triglyceride and cholesterol esters. Our results demonstrated further that a significantly greater quantity of 14C-labelled erucate than labelled palmitate, oleate or linoleate was incorporated into the cholesterol ester fraction of the control aorta. The incorporation rates of erucate and linoleate into phosphatidic acid were more rapid, while the rates of erucate into phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and lysophosphatidylcholine were significantly slower than those of other fatty acids. PMID:7236017

Kako, K J; Vasdev, S C

1980-01-01

343

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

PubMed Central

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

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

2012-01-01

344

Docosahexaenoic acid ester of phloridzin inhibit lipopolysaccharide-induced inflammation in THP-1 differentiated macrophages.  

PubMed

Phloridzin or phlorizin (PZ) is a predominant phenolic compound found in apple and also used in various natural health products. Phloridzin shows poor absorption and cellular uptake due to its hydrophilic nature. The aim was to investigate and compare the effect of docosahexaenoic acid (DHA) ester of PZ (PZ-DHA) and its parent compounds (phloridzin and DHA), phloretin (the aglycone of PZ) and cyclooxygenase inhibitory drugs (diclofenac and nimesulide) on production of pro-inflammatory biomarkers in inflammation-induced macrophages by lipopolysaccharide (LPS)-stimulation. Human THP-1 monocytes were seeded in 24-well plates (5×10(5)/well) and treated with phorbol 12-myristate 13-acetate (PMA, 0.1?g/mL) for 48h to induce macrophage differentiation. After 48h, the differentiated macrophages were washed with Hank's buffer and treated with various concentrations of test compounds for 4h, followed by the LPS-stimulation (18h). Pre-exposure of PZ-DHA ester was more effective in reducing tumor necrosis factor-alpha (TNF-?), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) protein levels compared to DHA and nimesulide. However, diclofenac was the most effective in reducing prostaglandin (PGE2) level by depicting a dose-dependent response. However, PZ-DHA ester and DHA were the most effective in inhibiting the activation of nuclear factor-kappa B (NF-?B) among other test compounds. Our results suggest that PZ-DHA ester might possess potential therapeutic activity to treat inflammation related disorders such as type 2 diabetes, asthma, atherosclerosis and inflammatory bowel disease. PMID:25637769

Sekhon-Loodu, Satvir; Ziaullah; Rupasinghe, H P Vasantha

2015-03-01

345

Salicylic acid (SA) bioaccessibility from SA-based poly(anhydride-ester).  

PubMed

The bioaccessibility of salicylic acid (SA) can be effectively modified by incorporating the pharmacological compound directly into polymers such as poly(anhydride-esters). After simulated digestion conditions, the bioaccessibility of SA was observed to be statistically different (p < 0.0001) in each sample: 55.5 ± 2.0% for free SA, 31.2 ± 2.4% the SA-diglycolic acid polymer precursor (SADG), and 21.2 ± 3.1% for SADG-P (polymer). The release rates followed a zero-order release rate that was dependent on several factors, including (1) solubilization rate, (2) macroscopic erosion of the powdered polymer, (3) hydrolytic cleavage of the anhydride bonds, and (4) subsequent hydrolysis of the polymer precursor (SADG) to SA and diglycolic acid. PMID:25082798

Rogers, Michael A; Yan, Yim-Fan; Ben-Elazar, Karen; Lan, Yaqi; Faig, Jonathan; Smith, Kervin; Uhrich, Kathryn E

2014-09-01

346

Separation of fatty acids or methyl esters including positional and geometric isomers by alumina argentation thin-layer chromatography.  

PubMed

This paper describes novel and rapid thin-layer chromatography procedures for the analysis of fatty acids and methyl esters using silver-impregnated alumina sheets. These techniques are known in most laboratories, and the equipment is readily available. The fatty acid method allows a separation of petroselinic (C18:1 delta 6c), oleic (C18:1 delta 9c), elaidic (C18:1 delta 9t), erucic (C22:1 delta 13c), and brassidic acids (C22:1 delta 13t), and the methyl ester method gives an excellent resolution with respect to the number, configuration, and position of the unsaturated centers. Sufficient separation for the subsequent ozonolysis and chromatographic quantification of isomeric C18 and C22 fatty acid methyl esters is obtained with both methods. PMID:3611285

Breuer, B; Stuhlfauth, T; Fock, H P

1987-07-01

347

Synthesis and Biological Activity of Arylspiroborate Salts Derived from Caffeic Acid Phenethyl Ester  

PubMed Central

Two novel boron compounds containing caffeic acid phenethyl ester (CAPE) derivatives have been prepared and characterized fully. These new compounds and CAPE have been investigated for potential antioxidant and antimicrobial properties and their ability to inhibit 5-lipoxygenase and whether chelation to boron improves their biological activity. Sodium salt 4 was generally more active than ammonium salt 5 in the biological assays and surpassed the radical scavenging ability of CAPE. Compounds 4 and 5 were more active than CAPE and Zileuton in human polymorphonuclear leukocytes. These results clearly show the effectiveness of the synthesized salts as transporter of CAPE.

Hébert, Martin J. G.; Flewelling, Andrew J.; Clark, Trevor N.; Jean-François, Jacques; Surette, Marc E.; Gray, Christopher A.; Vogels, Christopher M.; Touaibia, Mohamed; Westcott, Stephen A.

2015-01-01

348

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.

349

Synthesis and biological evaluation of isoflavone fatty acid esters with potential weight loss and hypolipidemic activities.  

PubMed

A series of isoflavone fatty acid esters were designed on the basis of endogenous oleoyl-estrone using estrogen moiety modification strategy. Ten new compounds were synthesized, and their body weight loss and hypolipidemic bioactivities were assayed. Some of these novel compounds could effectively inhibit the differentiation of 3T3-L1 preadipocytes in vitro. The most potent compound 1a significantly decreased the body weight and white adipose tissue weight in a high-fat diet-induced rat model. Also, compound 1a showed good hypolipidemic activity and low toxicity. PMID:20392645

Xiang, Hua; Zhao, Wei; Xiao, Hong; Qian, Lei; Yao, Yao; Li, Xiao-Bo; Liao, Qing-Jiang

2010-05-01

350

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 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...

2010-04-01

351

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

NASA Astrophysics Data System (ADS)

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.

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

2006-12-01

352

An efficient chiral synthesis of fluoro-containing amino acids: N-benzyloxycarbonyl-2-amino-4,4-difluorobutyric acid methyl ester and its analogs  

Microsoft Academic Search

Fluoro-containing amino acids, N-benzyloxycarbonyl-2-amino-4,4-difluorobutyric acid methyl ester and analogs, were prepared in high enantiomeric excess. Incorporation of 2-amino-4,4-difluoro butyric acid as P1 group provided a potent HCV NS3 protease inhibitor.

Zilun Hu; Wei Han

2008-01-01

353

The use of SEP-PAK C18 Cartridges in the Preparation of Bile Acid Methyl Ester Acetates  

Microsoft Academic Search

A method is described for the rapid and Quantitative extraction of bile acid derivates by Sep-Pak C18 cartridge. The method is used for the preparation of bile acid methyl ester acetates. The method was validated by determining the efficiency and the recovery of radiolabelled taurine-conjugated and free bile acids and of bile acid containing biological samples, by thin-layer chromatography with

Yvo Ghoos; Paul Rutgeerts; Gaston Vantrappen

1982-01-01

354

Preparation of stearoyl lactic acid ester catalyzed by lipases from Rhizomucor miehei and porcine pancreas optimization using response surface methodology  

Microsoft Academic Search

The esterification reaction between stearic acid and lactic acid using Rhizomucor miehei lipase and porcine pancreas lipase was optimized for maximum esterification using response surface methodology. The formation\\u000a of the ester was found to depend on three parameters namely enzyme\\/substrate ratio, lactic acid (stearic acid) concentration\\u000a and incubation period. The maximum esterification predicted by theoretical equations for both lipases matched

K. R. Kiran; N. G. Karanth; S. Divakar

1999-01-01

355

Manganese-Catalyzed Synthesis of cis-?-Amino Acid Esters through Organometallic C?H Activation of Ketimines.  

PubMed

Manganese-catalyzed C?H functionalization reactions of ketimines set the stage for the expedient synthesis of cis-?-amino acid esters through site- and regioselective alkene annulations. The organometallic C?H activation occurred efficiently with high functional group tolerance, delivering densely functionalized ?-amino acid derivatives with ample scope. PMID:25663350

Liu, Weiping; Zell, Daniel; John, Michael; Ackermann, Lutz

2015-03-23

356

Production of Fatty Acid Methyl Esters via the In Situ Transesterification of Soybean Oil in Carbon Dioxide-Expanded Methanol  

Technology Transfer Automated Retrieval System (TEKTRAN)

The production of fatty acid methyl esters (FAME) by direct alkali- and acid-catalyzed in situ transesterification of soybean flakes in CO2-expanded methanol was examined at various temperatures and pressures. Attempts to synthesize FAME from soy flakes via alkaline catalysis, using sodium methoxid...

357

62 Langmuir 1987,3, 62-76 Reactivity of Carboxylic Acid and Ester Groups in the  

E-print Network

on structure in ways having no analogy in reactions in solution. For example, the rate of base62 Langmuir 1987,3, 62-76 Reactivity of Carboxylic Acid and Ester Groups in the Functionalized Interfacial Region of "Polyethylene Carboxylic Acid" (PE-C02H) and Its Derivatives: Differentiation

Prentiss, Mara

358

Cholestane as a digestibility marker in the absorption of polyunsaturated fatty acid ethyl esters in Atlantic salmon.  

PubMed

Salmonid fish require long-chain n-3 fatty acids in their diet. The digestibility of different chemical forms of fish oil fatty acids, fed as triacylglycerols, free fatty acids or ethyl esters, was examined in 300 g farmed Atlantic salmon (Salmo salar) using cholestane as an indicator of fat absorption in lieu of the chromium oxide (Cr2O3) which is commonly used as a marker in digestibility studies. It was established that the two digestibility markers gave similar results. Conveniently, cholestane does not require a separate analysis if fatty acids are to be determined by appropriate gas-liquid chromatography. The long-chain polyunsaturated fatty acids were particularly well absorbed, the apparent digestibility being 90-98% when feeding triacylglycerols or free fatty acids. However, the digestibility of monounsaturated fatty acids (75-94%) was lower, and lower still for saturated fatty acids (50-80%). Ethyl esters of fatty acids were significantly less well absorbed (P less than 0.05) than were the corresponding fatty acids in free acid or triacylglycerol form. Irrespective of dietary fat type, only free fatty acids were identified in feces, indicating total hydrolysis of triacylglycerols and ethyl esters. PMID:1630276

Sigurgisladottir, S; Lall, S P; Parrish, C C; Ackman, R G

1992-06-01

359

Acid-cleavable ketal containing poly(?-amino ester) for enhanced siRNA delivery.  

PubMed

The safe and effective intracellular delivery of nucleic acids remains the most challenging obstacle to the broad application of gene therapy in clinic. Endosomal escape of nucleic acids is also a major barrier for efficient gene delivery. Ketal linkage is known to readily cleave at the acidic pH of endosomal compartments. Here, we report ketal containing poly(?-amino ester) (KPAE) as an acid-cleavable non-viral siRNA delivery system. KPAE efficiently condensed siRNA into nanocomplexes with a diameter of ? 150 nm, which are stable under neutral conditions but rapidly dissociate to release siRNA at acidic pH. KPAE had a buffering capacity due to the presence of secondary amines in its backbone, confirmed by acid-base titration. Moreover, the studies of confocal fluorescence imaging using calcein and LysoTracker Red revealed that KPAE disrupted endosomes by colloid osmotic mechanism and "proton sponge" effects. Cell culture studies demonstrated that KPAE can deliver tumor necrosis factor-? (TNF-?) siRNA to lipopolysaccharide (LPS)-stimulated macrophages and significantly inhibit the expression of TNF-?. The results demonstrate that acid-cleavable KPAE has great potential as gene delivery systems based on its excellent biocompatibility, pH sensitivity and high gene delivery efficiency. PMID:23796834

Guk, Kyeonghye; Lim, Hyungsuk; Kim, Byungkuk; Hong, Minsung; Khang, Gilson; Lee, Dongwon

2013-09-10

360

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

PubMed

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

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

2014-01-01

361

Perennial peanut (Arachis glabrata Benth.) leaves contain hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase activity and accumulate hydroxycinnamoyl-tartaric acid esters.  

PubMed

Many plants accumulate hydroxycinnamoyl esters to protect against abiotic and biotic stresses. Caffeoyl esters in particular can be substrates for endogenous polyphenol oxidases (PPOs). Recently, we showed that perennial peanut (Arachis glabrata Benth.) leaves contain PPO and identified one PPO substrate, caftaric acid (trans-caffeoyl-tartaric acid). Additional compounds were believed to be cis- and trans-p-coumaroyl tartaric acid and cis- and trans-feruloyl-tartaric acid, but lack of standards prevented definitive identifications. Here we characterize enzymatic activities in peanut leaves to understand how caftaric acid and related hydroxycinnamoyl esters are made in this species. We show that peanut leaves contain a hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase (HTT) activity capable of transferring p-coumaroyl, caffeoyl, and feruloyl moieties from CoA to tartaric acid (specific activities of 11 ± 2.8, 8 ± 1.8, 4 ± 0.8 pkat mg(-1) crude protein, respectively). The HTT activity was used to make cis- and trans-p-coumaroyl- and -feruloyl-tartaric acid in vitro. These products allowed definitive identification of the corresponding cis- and trans-hydroxycinnamoyl esters extracted from leaves. We tentatively identified sinapoyl-tartaric acid as another major phenolic compound in peanut leaves that likely participates in secondary reactions with PPO-generated quinones. These results suggest hydroxycinnamoyl-tartaric acid esters are made by an acyltransferase, possibly a BAHD family member, in perennial peanut. Identification of a gene encoding HTT and further characterization of the enzyme will aid in identifying determinants of donor and acceptor substrate specificity for this important class of biosynthetic enzymes. An HTT gene could also provide a means by genetic engineering for producing caffeoyl- and other hydroxycinnamoyl-tartaric acid esters in forage crops that lack them. PMID:24556732

Sullivan, Michael L

2014-05-01

362

Dimer esters in ?-pinene secondary organic aerosol: effect of hydroxyl radical, ozone, relative humidity and aerosol acidity  

NASA Astrophysics Data System (ADS)

The formation of secondary organic aerosol (SOA) from both ozonolysis and hydroxyl radical (OH)-initiated oxidation of ?-pinene under conditions of high nitric oxide (NO) concentrations with varying relative humidity (RH) and aerosol acidity was investigated in the University of North Carolina dual outdoor smog chamber facility. SOA formation from ozonolysis of ?-pinene was enhanced relative to that from OH-initiated oxidation in the presence of initially high NO conditions. However, no effect of RH on SOA mass was evident. Ozone (O3)-initiated oxidation of ?-pinene in the presence of ammonium sulfate (AS) seed coated with organic aerosol from OH-initiated oxidation of ?-pinene showed reduced nucleation compared to ozonolysis in the presence of pure AS seed aerosol. The chemical composition of ?-pinene SOA was investigated by ultra-performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS), with a focus on the formation of carboxylic acids and high-molecular weight dimer esters. A total of eight carboxylic acids and four dimer esters were identified, constituting between 8 and 12% of the total ?-pinene SOA mass. OH-initiated oxidation of ?-pinene in the presence of nitrogen oxides (NOx) resulted in the formation of highly oxidized carboxylic acids, such as 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) and diaterpenylic acid acetate (DTAA). The formation of dimer esters was observed only in SOA produced from the ozonolysis of ?-pinene in the absence of NOx, with increased concentrations by a~factor of two at higher RH (50-90%) relative to lower RH (30-50%). The increased formation of dimer esters correlates with an observed increase in new particle formation at higher RH due to nucleation. Increased aerosol acidity was found to have a negligible effect on the formation of the dimer esters. SOA mass yield did not influence the chemical composition of SOA formed from ?-pinene ozonolysis with respect to carboxylic acids and dimer esters. The results support the formation of the high-molecular weight dimer esters through gas-phase reactions of the stabilized Criegee Intermediate (sCI) formed from the ozonolysis of ?-pinene. The high molecular weight and polar nature of dimer esters formed in the gas-phase may explain increased particle number concentration as a~result of homogenous nucleation. Since three of these dimer esters (i.e., pinyl-diaterpenyl ester (MW 358), pinyl-diaterebyl ester (MW 344) and pinonyl-pinyl ester (MW 368)) have been observed in both laboratory-generated and ambient fine organic aerosol samples, we conclude that the dimer esters observed in this study can be used as tracers for the O3-initiated oxidation of ?-pinene, and are therefore indicative of enhanced anthropogenic activities, and that the high molecular weight and low volatility esters result in homogenous nucleation under laboratory conditions, increasing the particle number concentration.

Kristensen, K.; Cui, T.; Zhang, H.; Gold, A.; Glasius, M.; Surratt, J. D.

2013-12-01

363

A monolithic lipase reactor for biodiesel production by transesterification of triacylglycerides into fatty acid methyl esters  

PubMed Central

An enzymatic reactor with lipase immobilized on a monolithic polymer support has been prepared and used to catalyze the transesterification of triacylglycerides into the fatty acid methyl esters commonly used for biodiesel. A design of experiments procedure was used to optimize the monolithic reactor with variables including control of the surface polarity of the monolith via variations in the length of the hydrocarbon chain in alkyl methacrylate monomer, time of grafting of 1-vinyl-4,4-dimethylazlactone used to activate the monolith, and time used for the immobilization of porcine lipase. Optimal conditions involved the use of a poly(stearyl methacrylate-co-ethylene dimethacrylate) monolith, grafted first with vinylazlactone, then treated with lipase for 2 h to carry out the immobilization of the enzyme. Best conditions for the transesterification of glyceryl tributyrate included a temperature of 37°C and a 10 min residence time of the substrate in the bioreactor. The reactor did not lose its activity even after pumping through it a solution of substrate equaling 1,000 reactor volumes. This enzymatic reactor was also used for the transesterification of triacylglycerides from soybean oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. PMID:21915852

Urban, Jiri; Svec, Frantisek; Fréchet, Jean M.J.

2011-01-01

364

Assessment of ionic liquid stationary phases for the GC analysis of fatty acid methyl esters.  

PubMed

The gas chromatographic separation of fatty acid methyl esters (FAMEs) on ionic liquid stationary phases was investigated. Seven commercially available ionic liquid columns were tested using a test mixture containing 37 fatty acid methyl esters. The influence of column temperature on the elution order was studied using five different temperature programs. Retention times were highly reproducible. Similar retention behavior was observed for the IL59, IL60, and IL61 columns. The peak pair C18:1 cis/trans was not baseline resolved on these columns, whose stationary phases are highly similar. C18:2 cis/trans, C18:3 n6/n3, and C20:3 n6/n3 were baseline separated on all columns. Baseline separation of the complete test mix was only obtained on the IL82 column using a heating rate of 5 K/min. In general, retention times decreased with increasing column polarity but unsaturated FAMEs were retained stronger compared to their saturated counterparts. Except for the IL59 column, retention crossover was observed when the temperature program was changed. PMID:24965160

Dettmer, Katja

2014-08-01

365

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

PubMed

In this study, we synthesized dimer acid (DA) esters, having short to long alkyl chains, (DA-Cn) by the Diels-Alder reaction and subsequent esterification reaction of fatty acids that were prepared by the hydrolysis of waste vegetable oil. It was found that the DA-Cn were thermally more stable than common petroleum-based plasticizer DOP. When the DOP, DA, or DA-Cn with short alkyl chains were added to ethyl cellulose (EC), the optical clarity and SEM images of the samples showed their good miscibility with those additives in a micro-scale. It was also found that the rubbery modulus of the EC decreased with increasing amount of additives; the type of the additives did not affect the rates of the decrease in the rubbery modulus. The main transition temperatures of the EC containing either DA or DA-C1 or DA-C4 decreased with increasing amounts of those additives and were comparable to that of the DOP-containing EC. The above findings suggested that the DA and its esters with short alkyl chains could act as effective plasticizer and, thus, could be used instead of the DOP. In addition, the results obtained from tensile testing and leaching experiments implied that the DA might be better plasticizer than the DA-C1 and DA-C4, at least in some cases, because of hydrogen-bonding with the EC. PMID:25659700

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

2015-05-01

366

Electrical properties of pSi/[6,6] phenyl-C61 butyric acid methyl ester/Al hybrid heterojunctions: Experimental and theoretical evaluation of diode operation  

NASA Astrophysics Data System (ADS)

In this work, we analyze electrically the Al/p-Si/[6,6] phenyl-C61 butyric acid methyl ester/Al hybrid heterojunction. The barrier height at the p-Si/PCBM interface corresponding to the difference between Si valence band edge and the lowest unoccupied molecular orbital energy level of PCBM is studied with current-voltage (J-V) and capacitance-voltage (C-V) methods and determined to be ?0.55 eV. This value is in agreement with the onset energy of spectrally resolved photocurrent measurements presented in a previous publication [Matt et al., Adv. Mater. 22, 647 (2010)]. For the J-V characteristics, a thorough model based on an interface generation-recombination current is proposed. All relevant energy levels for this model are obtained experimentally. As origin of the large reverse current, the thermal generation of charge carriers throughout the Si depletion region is identified by the thermal activation measurements.

Bednorz, Mateusz; Fromherz, Thomas; Matt, Gebhard J.; Brabec, Christoph J.; Scharber, Markus; Serdar Sariciftci, N.

2012-12-01

367

Silicic acid biogeochemistry in the Gulf of California: Insights from sedimentary Si isotopes  

NASA Astrophysics Data System (ADS)

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.

Pichevin, Laetitia; Ganeshram, Raja S.; Reynolds, Ben C.; Prahl, Fredrick; Pedersen, Thomas F.; Thunell, Robert; McClymont, Erin L.

2012-06-01

368

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

USGS Publications Warehouse

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.

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

1994-01-01

369

Molecular recognition of isomeric protonated amino acid esters monitored by ESI-mass spectrometry  

PubMed Central

Summary Two new 9,9’-spirobifluorene-derived crown ethers were prepared and used to recognise constitutionally isomeric amino acid derivatives. The performance of the receptors was evaluated by ESI-mass spectrometry using the isomer labelled guest method (ILGM). This method revealed the preferred binding of L-norleucine and L-leucine compared to L-isoleucine for both receptors. Furthermore, non-covalent isotope effects demonstrate the relevance of dispersive interactions for the overall binding event. These effects also provide hints for the relative spatial orientation of the guest molecules within the host–guest complex, and thereby prove the importance of the spirobifluorene moiety for the observed binding of the protonated amino acid esters. PMID:24778737

Liesenfeld, Andrea

2014-01-01

370

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

PubMed

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

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

2011-01-01

371

Effect of silicic acid on arsenate and arsenite retention mechanisms on 6-L ferrihydrite: A spectroscopic and batch adsorption approach  

PubMed Central

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

Gao, Xiaodong; Root, Robert A.; Farrell, James; Ela, Wendell; Chorover, Jon

2014-01-01

372

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

Microsoft Academic Search

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

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

2011-01-01

373

Supported phosphate and carbonate salts for heterogeneous catalysis of triglycerides to fatty acid methyl esters  

NASA Astrophysics Data System (ADS)

Fatty acid methyl esters made from vegetable oil, or biodiesel, have been identified as a substitute for diesel derived from crude oil. Biodiesel is currently made using a homogeneous base catalyst to perform the transesterification of triglycerides with methanol to generate fatty acid methyl esters (FAME). The use of a homogeneous catalyst necessitates additional purification of the product and byproducts before sale, and the catalyst is consumed and discarded. The development of a heterogeneous basic catalyst for the production of FAME is desirable. Tribasic phosphate salts and dibasic carbonate salts are active for the production of FAME but generally operate as homogeneous catalysts. Supporting these phosphate and carbonate salts on mesoporous MCM-41, microporous silica gel, and nonporous a-alumina proved successful to greater or lesser degrees depending on the identity of the support and pretreatment of the support. Although these salts were supported and were active for the production of FAME from canola oil, they proved to be operating as homogeneous catalysts due to leaching of the active species off the surface of the support. Further investigation of the active species present in the tribasic phosphate catalysts identified the active support as orthophosphate, and NMR studies revealed the phosphorus to be present as orthophosphate and diphosphate in varying proportions in each catalyst. Evaluation of the acid-washing support pretreatment process revealed that the exposure of the support to acid plays a large role in the development of activity on the surface of the catalyst, but manipulation of these parameters did not prevent leaching of the active site off the surface of the catalyst. Alternate methods of support pretreatment were no more effective in preventing leaching. Tribasic phosphate supported on silica gel is not effective as a heterogeneous catalyst for FAME production from triglycerides because of the lack of stability of the phosphate on the support. The support is not stable under the reaction conditions, and alternatives should be explored to develop a heterogeneous base catalyst for the production of FAME.

Britton, Stephanie Lynne

374

The fusion of erythrocytes by fatty acids, esters, retinol and ?-tocopherol  

PubMed Central

1. The ability of a number of carboxylic acids, their esters, retinol and ?-tocopherol to induce fusion of hen erythrocytes in vitro was investigated. 2. Some 30 different fat-soluble substances (100?g/ml) were found to cause the formation of multinucleated erythrocytes with a suspension of 3×108 erythrocytes/ml. The most effective agents induced fusion within 5–10min at 37°C; some substances required about 1h. 3. Inclusion of Dextran 60C in the test medium minimized colloid osmotic lysis caused by exogenous lipids that induce cell fusion. 4. Cell swelling, followed by cell adhesion, was then seen to precede cell fusion. 5. Fusion occurred with C10–C14 saturated carboxylic acids, with unsaturated, longer-chain carboxylic acids and their mono-esters; retinol, and to a lesser extent ?-tocopherol, also caused cell fusion. 6. C6–C9, C15, C16 and C18 saturated carboxylic acids did not induce fusion within 4h; glyceryl dioleate was only weakly active, and glyceryl trioleate was inactive in the test system. 7. Fusion was facilitated by a high ratio of chemical agents to cell number and by incubation between pH5 and 6. It was inhibited by EDTA and by serum albumin. 8. Glyceryl mono-oleate caused both a similar fusion of several species of mammalian erythrocyte and the interspecific fusion of human and chicken erythrocytes. 9. The term `fusogenic' is proposed to describe chemical, viral and physical agents that cause membranes to fuse. 10. The biochemical mechanisms involved and the possible biological significance of membrane fusion by fusogenic lipids are discussed. ImagesPLATE 2PLATE 1 PMID:4204034

Ahkong, Q. F.; Fisher, D.; Tampion, W.; Lucy, J. A.

1973-01-01

375

Occurrence of 3-MCPD fatty acid esters in human breast milk.  

PubMed

A series of twelve breast milk samples were analysed by gas chromatography-mass spectrometry (GC/MS) operated in selected ion monitoring mode for 3-chloropropane-1,2-diol (3-MCPD). Whilst none of the samples contained 3-MCPD above the limit of detection of 3 microg kg(-1) milk, all contained high amounts of 3-MCPD esterified with higher fatty acids. The levels of 3-MCPD released by hydrolysis of these esters (bound 3-MCPD) ranged from the limit of detection (300 microg kg(-1), expressed on a fat basis) to 2195 microg kg(-1); with a mean level of bound 3-MCPD of 1014 microg kg(-1), which corresponded to 35.5 microg kg(-1) milk. The presence of bound 3-MCPD was confirmed using orthogonal gas chromatography coupled with high-speed time-of-flight mass spectrometry analysis for four randomly selected breast milk samples. Six breast milks collected from one of the nursing mothers 14-76 days after childbirth contained bound 3-MCPD within the range of 328-2078 microg kg(-1) fat (mean 930 microg kg(-1) fat). The calculated bound 3-MCPD content of these samples was within the range of 6 and 19 microg kg(-1) milk (mean of 12 microg kg(-1) milk). The major types of 3-MCPD esters were the symmetric diesters with lauric, palmitic, and oleic acids, and asymmetric diesters with palmitic acid/oleic acid among which 3-chloro-1,2-propanediol 1,2-dioleate prevailed. PMID:18484295

Zelinková, Z; Novotný, O; Sch?rek, J; Velísek, J; Hajslová, J; Dolezal, M

2008-06-01

376

Synthesis of tyrosinase inhibitory (4-oxo-4H-pyran-2-yl)acrylic acid ester derivatives.  

PubMed

Melanogenesis is a physiological process that results in the production of melanin pigment. However, excessive accumulations of epidermal pigmentation can cause various hyperpigmentary disorders such as, melasma and age spots. Kojic acid and hydroxylated cinnamic acid derivatives are known to inhibit tyrosinase, a key component of melanin biosynthesis. Pyronyl-acrylic acid esters 3a-i, which share structural features of kojic acid and hydroxylated cinnamic acid, were prepared and their abilities to inhibit tyrosinase and melanin production were evaluated. Of the esters synthesized, 3e and 3h, which derived from diethylene glycol moieties were found to inhibit melanin production by ca. 20% at 20 microg/ml, whereas kojic acid at 200 microg/ml inhibited melanin production by 15.8%. PMID:19022667

Kang, Soo Sung; Kim, Hyoung Ja; Jin, Changbae; Lee, Yong Sup

2009-01-01

377

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

SciTech Connect

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.

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

1990-11-01

378

An improved reversed-phase thin-layer chromatography method for separation of fatty acid methyl esters  

Microsoft Academic Search

Resolution of fatty acid methyl esters (FAME) by thin-layer chromatography often is complicated by co-migration of certain\\u000a acyl-isomers in heterogeneous mixtures. However, a novel reversed-phase thin-layer chromatography method which employs 10%\\u000a (wt\\/vol) silver nitrate in a mobile phase containing acetonitrile\\/1,4-dioxane\\/acetic acid (80:20:1, vol\\/vol\\/vol) allows one-dimensional\\u000a resolution of a wide range of acyl-methyl esters. This innovation enables improved separation of saturated

T. C. Marquardt; R. F. Wilson

1998-01-01

379

Electrochemical fluorination of 1-ethylpiperazine and 4-methyl- and\\/or 4-ethylpiperazinyl substituted carboxylic acid methyl esters  

Microsoft Academic Search

Electrochemical fluorination (ECF) of 1-ethylpiperazine and eight methyl esters of 4-methyl- and\\/or 4-ethylpiperazinyl substituted carboxylic acids were studied. Corresponding perfluoro(4-fluoro-1-ethylpiperazine) was obtained from 1-ethylpiperazine in a small yield along with perfluoro(1-methyl-3-ethylimidazolidine), perfluoro[2-(N?,N?-difluoroaminoethyl)-N,N-diethylamine)] and perfluorotriethylamine. The corresponding mono-basic perfluoroacid fluorides with a perfluoro(4-alkylpiperazinyl) group were obtained in fair to good yields from the fluorination of methyl esters of 4-alkylpiperazinyl-substituted carboxylic acids.

Takashi Abe; Hajime Baba; Irina Soloshonok

2001-01-01

380

Kinetic resolution of racemic mandelic acid esters by N,N'-dioxide-scandium-complex-catalyzed enantiomer-selective acylation.  

PubMed

A simple and efficient acylative kinetic resolution of racemic mandelic acid esters was accomplished with a chiral N,N'-dioxide-scandium(III) complex under mild and base-free reaction conditions. A variety of mandelic acid esters performed well in the reaction, obtaining both acylated products (up to 49% yield, 97% ee) and recovered substrates (up to 49% yield, 95% ee) in high enantioselectivities with perfect selectivity factors (up to 247). The enantioselective recognition and catalytic models were also proposed for the catalytic KR reaction. PMID:25284213

Zhang, Yuheng; Liu, Xiaohua; Zhou, Lin; Wu, Wangbin; Huang, Tianyu; Liao, Yuting; Lin, Lili; Feng, Xiaoming

2014-11-24

381

A qualitative study on the chemical composition of ester-bound moieties in an acidic andosolic forest soil  

Microsoft Academic Search

Solvent insoluble ester-bound moieties, released after base treatment from an acidic andosolic forest soil A-horizon from Madeira, were sequentially extracted and analysed using gas chromatography and gas chromatography–mass spectrometry. The separation of all moieties released into several pH “subfractions” allowed the various products released to be studied in detail. The distributions obtained for 2-alkanols, diols, n-alkanols, n-alkanoic acids, ?-hydroxy acids,

Dennis F. W Naafs; Pim F van Bergen

2002-01-01

382

Semi-synthesis of new antimicrobial esters from the natural oleanolic and maslinic acids.  

PubMed

In this article, we report an effective procedure for the selective isolation of oleanolic acid 1 and maslinic acid 2 (3.4 and 8.5mg/g DW, respectively) from pomace olive (Olea europaea L.) using an ultrasonic bath, and the synthesis of a series of new triterpenic acid esters. The compounds were characterized by their spectral data and were evaluated for their antimicrobial activity. Among the compounds tested, those having sulfur and chlorine atoms were found to be antibacterial. They showed activity against two Gram-positive bacteria Staphylococcus aureus and Enterococcus faecalis and two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa (MICs within a range of 5-25?g/mL). The fungus Penicillium italicum was found to be the most sensitive to both sulfur derivatives: (3?)-3-((thiophene-2-carbonyl)oxy)-olean-12-en-28-oic acid (1a) (IZ=22mm) and (2?,3?-2,3-bis((thiophene-2-carbonyl)oxy)olean-12-en-28-oic acid (2a) (IZ=24mm). PMID:25863603

Chouaïb, Karim; Hichri, Fayçal; Nguir, Asma; Daami-Remadi, Majda; Elie, Nicolas; Touboul, David; Ben Jannet, Hichem; Hamza, M'hamed Ali

2015-09-15

383

Synthesis of the 2?,3?- and 2?,3?-isomers of 3-( p-substituted phenyl)tropane-2-carboxylic acid methyl esters  

Microsoft Academic Search

The synthesis of 3-(p-substituted phenyl)trop-2-carboxylic acid methyl ester 8 and its reduction with samarium iodide provide a new synthesis of 3?-(4?-substituted phenyl)tropane-2?-carboxylic acid methyl ester (2) and, in addition, give the first synthesis of the 2?,3?-diastereoisomer 4.

Kathryn I. Keverline; Philip Abraham; Anita H. Lewin; F. Ivy Carroll

1995-01-01

384

40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...  

Code of Federal Regulations, 2014 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...acid (H3 BO3 ), mixed esters with polyethylene glycol mono-Bu ether and...

2014-07-01

385

40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...  

Code of Federal Regulations, 2011 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and...

2011-07-01

386

40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...  

Code of Federal Regulations, 2012 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...acid (H3 BO3 ), mixed esters with polyethylene glycol mono-Bu ether and...

2012-07-01

387

40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...  

Code of Federal Regulations, 2013 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...acid (H3 BO3 ), mixed esters with polyethylene glycol mono-Bu ether and...

2013-07-01

388

40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...  

Code of Federal Regulations, 2010 CFR

...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section...Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and...

2010-07-01

389

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

Code of Federal Regulations, 2011 CFR

40 Protection of Environment 31 2011-07-01 2011-07-01...butyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1730 Section 721.1730 Protection of Environment ENVIRONMENTAL PROTECTION...?-butyl-?-hydroxy, ester with boric acid (H3BO3). (a)...

2011-07-01

390

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

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01...methyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL PROTECTION...?-methyl-?-hydroxy, ester with boric acid (H3BO3). (a)...

2010-07-01

391

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

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30 2010-07-01 2010-07-01...butyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1730 Section 721.1730 Protection of Environment ENVIRONMENTAL PROTECTION...?-butyl-?-hydroxy, ester with boric acid (H3BO3). (a)...

2010-07-01

392

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

Code of Federal Regulations, 2011 CFR

40 Protection of Environment 31 2011-07-01 2011-07-01...methyl-Ï-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL PROTECTION...?-methyl-?-hydroxy, ester with boric acid (H3BO3). (a)...

2011-07-01

393

A simple and convenient method for preparation of carboxylic acid alkyl esters, phenolic and thioesters using chlorodiphenylphosphine\\/I 2 and imidazole reagent system  

Microsoft Academic Search

Condensation of carboxylic acids with alcohols, phenols and thiols proceeded smoothly to afford carboxylic acid alkyl esters, phenolic esters and thioesters by using the combination of chlorodiphenylphosphine, imidazole and molecular iodine in refluxing acetonitrile. Esterification with this mixed reagent system gave the corresponding products in excellent yields. The phosphorus-containing byproduct was simply removed from the organic phase by basic aqueous

Najmeh Nowrouzi; Abdol Mohammad Mehranpour; Javad Ameri Rad

2010-01-01

394

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

PubMed

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

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

2014-07-01

395

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

PubMed

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

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

2012-06-01

396

Spectrophotometric Study of the Interaction Np(VI) with Orthosilicic Acid and Polymeric Silicic Acids in Aqueous Solutions  

SciTech Connect

Spectrophotometric methods were used to investigate the interaction of the NpO22+ ion with orthosilicic acid, Si(OH)4, and polymeric silicic acids (PSA) in aqueous solutions. At ?? ? 4.5, the interaction is described by the reaction NpO22+ + Si(OH)4 = NpO2OSi(OH)3+ + H+ with an equilibrium constant of lg K = -2.88 ± 0.12 (ionic strength I = 0.1-0.2). Recalculation to I = 0 gives lg K0 =-2.61 ± 0.12; the stability constant of the complex NpO2OSi(OH)3+ is lg ?0 = 7.20 ± 0.12. Polymerization of Si(OH)4 does not lead to an apparent increase in the constant K. In solutions with ?? higher than 5, and with silicate concentration more than 0.02 mole/l, leads to formation of a second complex, whose structure probably is described by the formula NpO2(?SiO)2(?SiOH)m-2, where (?SiOH)m designates the PSA molecule with superficial Si-OH groups. The factors influencing the apparent equilibrium constants in forming of complexes NpO2OSi(OH)3+ and NpO2(?SiO)2(?SiOH)m-2 are considered upon polymerization of Si(OH)4. Absorption spectra of complexes NpO2OSi(OH)3+ and NpO2(?SiO)2(?SiOH)m-2 were obtained. Molar extinction coefficients at the maxima (500-600 nanometers) are much higher than those of the Np(VI) aquo ion and are about 25-30 l/mol?cm. The stabilities of silicate complexes of all types - MO2OSi(OH)3+, MO2(?SiO)2(?SiOH)m-2, or MO2SiO3 (M = U, Np, or Pu) - decrease in order U> Np> Pu with the greatest difference occurring between Np and Pu.

Yusov, A. B.; Shilov, V. P.; Fedoseev, A. M.; Astafurova, L. N.; Delegard, Calvin H.

2005-07-15

397

Mobilization of lead by esters of meso-2,3-dimercaptosuccinic acid  

SciTech Connect

An examination was made of the relative efficacies of 2,3-dimercapto-1-propanol (BAL) and three diesters (CH(SH)COOR)2; DMDMS, R = CH3; DEDMS, R = C2H5; and Di-PDMS, R = CH(CH3)2 of meso-2,3-dimercaptosuccinic acid (DMSA) in mobilizing freshly injected lead from mice. These diesters, like BAL, reduced the lead levels resulting from freshly injected lead in both the soft tissues (liver, kidneys, spleen, and brain) and the bone (tibia). After treatment with the dimethyl (DMDMS), the diethyl (DEDMS), and the diisopropyl (Di-PDMS) esters the lead content of each of the organs was significantly less than that present in the untreated controls. Each of the diesters reduced lead levels in the kidneys, liver, and spleen significantly below those levels found after BAL treatment. The action of the diesters in reducing brain lead levels was comparable to that of BAL. Di-PDMS was the most effective of these compounds and was significantly superior to BAL. Each of the esters was also significantly more effective than BAL in reducing the whole body level of lead.

Singh, P.K.; Jones, M.M.; Xu, Z.; Gale, G.R.; Smith, A.B.; Atkins, L.M. (Vanderbilt Univ., Nashville, TN (USA))

1989-01-01

398

Fabrication of biodegradable poly(ester-amide)s based on tyrosine natural amino acid.  

PubMed

N,N'-Bis[2-(methyl-3-(4-hydroxyphenyl)propanoate)]isophthaldiamide (5), a novel diol monomer containing chiral group, was prepared by the reaction of S-tyrosine methyl ester (3) with isophthaloyl dichloride (4a). A new family of optically active and potentially biodegradable poly(ester-amide)s (PEAs) based on tyrosine amino acid were prepared by the polycondensation reaction of diol monomer 5 with several aromatic diacid chlorides. The resulting new polymers were obtained in good yields with inherent viscosities ranging between 0.25 and 0.42 dL/g and are soluble in polar aprotic solvents. They showed good thermal stability and high optical purity. The synthetic compounds were characterized and studied by FT-IR, 1H-NMR, specific rotation, elemental and thermogravimetric analysis (TGA) techniques and typical ones by 13C-NMR, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) analysis. Soil burial test of the diphenolic monomer 5, and obtained PEA6a, and soil enzymatic assay showed that the synthesized diol and its polymer are biologically active and probably biodegradable in soil environment. PMID:21607747

Abdolmaleki, Amir; Mallakpour, Shadpour; Borandeh, Sedigheh; Sabzalian, Mohammad R

2012-05-01

399

High-throughput and sensitive analysis of 3-monochloropropane-1,2-diol fatty acid esters in edible oils by supercritical fluid chromatography/tandem mass spectrometry.  

PubMed

We have established a high-throughput and sensitive analytical method based on supercritical fluid chromatography (SFC) coupled with triple quadrupole mass spectrometry (QqQ MS) for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters in edible oils. All analytes were successfully separated within 9 min without sample purification. The system was precise and sensitive, with a limit of detection less than 0.063 mg/kg. The recovery rate of 3-MCPD fatty acid esters spiked into oil samples was in the range of 62.68-115.23%. Furthermore, several edible oils were tested for analyzing 3-MCPD fatty acid ester profiles. This is the first report on the analysis of 3-MCPD fatty acid esters by SFC/QqQ MS. The developed method will be a powerful tool for investigating 3-MCPD fatty acid esters in edible oils. PMID:22749582

Hori, Katsuhito; Matsubara, Atsuki; Uchikata, Takato; Tsumura, Kazunobu; Fukusaki, Eiichiro; Bamba, Takeshi

2012-08-10

400

Aliphatic fatty acids and esters: inhibition of growth and exoenzyme production of Candida, and their cytotoxicity in vitro: anti-Candida effect and cytotoxicity of fatty acids and esters.  

PubMed

The secretion of extracellular phospholipases and proteinases of Candida has been described as a relevant virulence factor in human infections. Aliphatic fatty acids have antimicrobial properties, but the mechanism by which they affect the virulence factors of microorganisms, such as Candida, is still unclear, and there are a few reports about their toxicity. The current study investigated the in vitro antifungal activity, exoenzyme production and cytotoxicity of some aliphatic fatty acids and their ester derivatives against the Candida species. The minimum inhibitory concentration and minimum fungicidal concentrations of aliphatic medium-chain fatty acids, methyl and ethyl esters were performed using the CLSI M27-A3 method and the cytotoxicity assay was performed according to ISO 10993-5. The influence of these compounds in the inhibition of the production of hydrolytic enzymes, phospholipases and proteinases by Candida was also investigated. Data analysis was performed using the one-way ANOVA method (p?0.05). In relation to the MIC against Candida species, the fatty acid with the best result was Lauric acid, although its ester derivatives showed no activity. The inhibition of phospholipase production was more significant than the inhibition of proteinase production by Candida. Tested fatty acids revealed more than 80% cell viability in their MIC concentrations. Additionally, a cell viability of 100% was reported at concentrations of anti-enzymatic effect. Therefore, the potential use of these fatty acids could be the basis for more antimicrobial tests. PMID:24907517

Souza, Juliana L S; da Silva, Adriana F; Carvalho, Pedro H A; Pacheco, Bruna S; Pereira, Cláudio M P; Lund, Rafael G

2014-09-01

401

40 CFR 721.10448 - Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine...  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

402

Spectroscopic, thermal and single crystal structure investigations of 2-bromotrimesic acid and its trimethyl ester analogue  

NASA Astrophysics Data System (ADS)

Two analogues of the well investigated trimesic acid viz. the 2-bromobenzene-1,3,5-tricarboxylic acid 1 and their ester trimethyl 2-bromobenzene-1,3,5-tricarboxylate 2, have been synthesised and their X-ray structures were solved. Acid 1 crystallises as 1:1 inclusion compound with water in a layer structure. Like in the solid state structure of trimesic acid, we found strong Osbnd H???O hydrogen bonds between one of the carboxyl groups and a neighbouring molecule to form a hydrogen bonding motif R22(8). Additionally, a water molecule and a second acid function of 1 are involved in further hydrogen bonding featuring the graph set R44(12) forming what might be called a water inserted dimer. As shown by TG-DSC measurements the water molecule in the 1:1 inclusion compound of 1 is engaged in two strong Osbnd H???O hydrogen bonds, it escapes at a rather low temperature of 99 °C. Bromine monosubstitution at the benzene ring forces the third carboxylic acid out of the mean plane of the molecule, which disturbs the coplanar arrangement of the three COOH moieties. Thus, the typical “chicken-wire” network formation is hindered. In the trimethyl 2-bromobenzene-1,3,5-tricarboxylate (2), the formation of strong Osbnd H???O hydrogen bonds is disabled by esterification of the acid functions. Nevertheless, the packing of 2 features solvent free molecular layers formed by Br???O contacts and connected van der Waals interactions. These layers are linked to each other by inverse bifurcated hydrogen bonds in term weak Csbnd H???O contacts. The results of the X-ray analysis could be confirmed by infrared spectroscopy.

Münch, Alexander S.; Katzsch, Felix; Gruber, Tobias; Mertens, Florian O. R. L.

2014-09-01

403

Yarrowia lipolytica lipase Lip2: an efficient enzyme for the production of concentrates of docosahexaenoic acid ethyl ester.  

PubMed

The production of Omega-3 (?-3) polyunsaturated fatty acids (PUFAs) rich in cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) was studied using lipase-catalysed hydrolysis of a mixture of ethyl esters from tuna oil. Lipases from Yarrowia lipolytica (YLL2), Thermomyces lanuginosus (TLL) and Candida rugosa (CRL1, CRL3 and CRL4) were tested. C. rugosa lipases discriminated esters on the basis of their chain length, with less affinity for ?-linolenate, 11-eicosenoate, arachidonate, EPA, DPA and DHA ethyl esters. However, YLL2 and TLL improved discrimination towards DHA, as enzyme selectivity was shown to be mainly based on the position of the double bond closest to the carboxylic group. From the point of view of kinetics, purity and yield, YLL2 was the most effective lipase for DHA purification. Using this enzyme in an open reactor process resulted in the highest concentrations of DHA ethyl ester (77%) and ?-3 esters (81%) with a recovery of 94% and 77% respectively. PMID:24657346

Casas-Godoy, Leticia; Meunchan, Muchalin; Cot, Marlène; Duquesne, Sophie; Bordes, Florence; Marty, Alain

2014-06-20

404

40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.  

Code of Federal Regulations, 2010 CFR

...2-[2-(ethenyloxy)ethoxy]ethyl ester. 721.10064 Section 721.10064...2-[2-(ethenyloxy)ethoxy]ethyl ester. (a) Chemical substance and significant...2-[2-(ethenyloxy)ethoxy]ethyl ester (PMN P-04-909; CAS No....

2010-07-01

405

Biodegradable coumaric acid-based poly(anhydride-ester) synthesis and subsequent controlled release.  

PubMed

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

Ouimet, Michelle A; Stebbins, Nicholas D; Uhrich, Kathryn E

2013-08-01

406

Determination of fatty acid ethyl esters in hair by GC–MS and application in a population of cocaine users  

Microsoft Academic Search

A gas chromatography–mass spectrometry method for the determination of ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate in hair samples was developed, validated and applied to real samples. Ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate are fatty acid ethyl esters (FAEE) which are known to be direct biotransformation products of ethanol. Their presence in the body fluids

Lucia Politi; Francesco Mari; Sandra Furlanetto; Ester Del Bravo; Elisabetta Bertol

2011-01-01

407

Determination of Total Lipids as Fatty Acid Methyl Esters (FAME) by in situ Transesterification: Laboratory Analytical Procedure (LAP)  

SciTech Connect

This procedure is based on a whole biomass transesterification of lipids to fatty acid methyl esters to represent an accurate reflection of the potential of microalgal biofuels. Lipids are present in many forms and play various roles within an algal cell, from cell membrane phospholipids to energy stored as triacylglycerols.

Van Wychen, S.; Laurens, L. M. L.

2013-12-01

408

Liver and Adipose Tissue Fatty Acid Ethyl Esters Obtained at Autopsy Are Postmortem Markers for Premortem Ethanol Intake  

Microsoft Academic Search

Background: Fatty acid ethyl esters (FAEEs) are nonoxi- dative ethanol metabolites that have been implicated as mediators of alcohol-induced organ damage. FAEEs are detectable in the blood after ethanol ingestion, and on that basis have been proposed as markers of ethanol intake. Because blood is not always available at autopsy, in this study we quantified FAEEs in human liver and

Majed A. Refaai; Phan N. Nguyen; Thora S. Steffensen; Richard J. Evans; Joanne E. Cluette-Brown; Michael Laposata

2002-01-01

409

Application of FAME (fatty acid methyl ester) analysis in the numerical taxonomic determination of bacterial guild structure  

Microsoft Academic Search

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

Lawrence M. Mallory; Gary S. Sayler

1984-01-01

410

Effects of caffeic acid phenethyl ester and epidermal growth factor on the development of caustic esophageal stricture in rats  

Microsoft Academic Search

Background\\/Purpose: An experimental study was performed to modify the healing response in caustic esophageal burns to prevent stricture development. Two different agents with different modes of actions, caffeic acid phenethyl ester (CAPE) and epidermal growth factor (EGF), were studied. CAPE has antiinflammatory, immunomodulatory, antioxidant, and antimitotic properties. EGF has known properties in supporting wound healing and in protecting esophagus from

Ramazan Kutlu; Abdurrahman Karaman

2001-01-01

411

Antioxidant activity of phenolic acids and esters present in red wine on human Low-Density Lipoproteins  

Microsoft Academic Search

To evaluate the antioxidant activity of different phenolic acids and their esters, three types of experiments have been used. Electron paramagnetic resonance (EPR) quantitative analysis was carried out using the acetaldehyde\\/xanthine oxidase system and Fenton's reaction to generate superoxide and hydroxyl radicals, respectively. In a second test, hydroperoxides generated by Cu2+-catalysed oxidation of low density lipoproteins (LDL) were quantified by

P. Urizzi; M.-C. Monje; J.-P. Souchard; A. Abella; J. Chalas; A. Lindenbaum; L. Vergnes; S. Labidalle; F. Nepveu

1999-01-01

412

THE GENERAL APPLICABILITY OF IN SITU TRANSESTERIFICATION FOR THE PRODUCTION OF FATTY ACID ESTERS FROM A VARIETY OF FEEDSTOCKS  

Technology Transfer Automated Retrieval System (TEKTRAN)

We have previously described a new approach to fatty acid methyl ester (FAME) production wherein acylglycerol transesterification was achieved by reacting flaked full fat soybeans with methanol containing NaOH. Efficient conditions for nearly quantitative transesterification of the lipid in the sub...

413

Improved Monitoring of Female Codling Moth (Lepidoptera: Tortricidae) with Pear Ester Plus Acetic Acid in Sex Pheromone-treated Orchards  

Technology Transfer Automated Retrieval System (TEKTRAN)

Catch of codling moth, Cydia pomonella (L.), in clear delta traps baited with ethyl (E,Z)-2,4-decadienoate (pear ester, PE) and acetic acid (AA) in separate lures (PE+AA) was compared with catch in orange delta traps baited with a single lure containing PE and the sex pheromone, (E,E)-8,10-dodecadie...

414

Stabilization of a tetrameric enzyme (?-amino acid ester hydrolase from Acetobacter turbidans) enables a very improved performance of ampicillin synthesis  

Microsoft Academic Search

The stabilized derivative of the enzyme ?-amino acid ester hydrolase from Acetobacter turbidans has been found to be very adequate as biocatalyst of the synthesis of the very relevant antibiotic ampicillin. This enzyme resulted much more adequate than the Penicillin G Acylase (PGA) from Escherichia coli (the most used enzyme). The stabilization of the enzyme was required because under optimal

Roberto Fernandez-Lafuente; Odette Hernández-Jústiz; Cesar Mateo; Marco Terreni; Jorge Alonso; Jose L. Garcia-López; Miguel A. Moreno; Jose M. Guisan

2001-01-01

415

Signi?cance of the detection of esters ofp-hydroxybenzoic acid(parabens) in human breast tumours  

Microsoft Academic Search

This issue of Journal of Applied Toxicology publishes the paper Concentrations of Parabens in Human Breast Tumours by Darbre et al. (2004), which reports that esters of p-hydroxybenzoic acid (parabens) can be detected in samples of tissue from human breast tumours. Breast tumour samples were supplied from 20 patients, in collaboration with the Edinburgh Breast Unit Research Group, and analysed

Philip W. Harvey; David J. Everett

2004-01-01

416

Combined effects of carbonation with heating and fatty acid esters on inactivation and growth inhibition of various bacillus spores.  

PubMed

The effects of carbonation treatment (1 to 5 MPa, 30 min) plus heat treatment (30 to 80°C, 30 min) in the presence of various fatty acid esters (FAEs; 0.05 and 0.1%, wt/vol) on counts of viable Bacillus subtilis spores were investigated. FAEs or carbonation alone had no inactivation or growth inhibition effects on B. subtilis spores. However, carbonation plus heat (CH; 80°C, 5 MPa, 30 min) in the presence of mono- and diglycerol fatty acid esters markedly decreased counts of viable spores, and the spore counts did not change during storage for 30 days. The greatest decrease in viable spore counts occurred in the presence of monoglycerol fatty acid esters. Under CH conditions, inactivation and/or growth inhibition occurred at only 80°C and increased with increasing pressure. The greatest decrease in spore counts (more than 4 log units) occurred with CH (80°C, 5 MPa, 30 min) in the presence of monoglycerol fatty acid esters. However, this treatment was less effective against Bacillus coagulans and Geobacillus stearothermophilus spores. PMID:23992501

Klangpetch, Wannaporn; Nakai, Tomoe; Noma, Seiji; Igura, Noriyuki; Shimoda, Mitsuya

2013-09-01

417

Development of a poly(ortho ester) prototype with a latent acid in the polymer backbone for 5-fluorouracil delivery  

Microsoft Academic Search

A study has been carried out to determine whether the latest family of poly(ortho esters) can be converted into a practical delivery system. This polymer differs from the previously described polymers in that it incorporates a short segment of a latent acid in the polymer backbone. The following issues were specifically addressed: (a) can the erosion and drug release be

S. Y Ng; H. R Shen; E Lopez; Y Zherebin; J Barr; E Schacht; J Heller

2000-01-01

418

Preparation of fatty acid methyl esters from hazelnut, high-oleic peanut and walnut oils and evaluation as biodiesel  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hazelnut, walnut and high-oleic peanut oils were converted into fatty acid methyl esters using catalytic sodium methoxide and evaluated as potential biodiesel fuels. These feedstocks were of interest due to their adaptability to marginal lands and their lipid production potentials (780-1780 L ha-1 y...

419

In vitro permeation through porcine buccal mucosa of caffeic acid phenetyl ester (CAPE) from a topical mucoadhesive gel containing propolis  

Microsoft Academic Search

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

G. C. Ceschel; P. Maffei; A. Sforzini; S. Lombardi Borgia; A. Yasin; C. Ronchi

2002-01-01

420

Dietary exposure of Hong Kong adults to fatty acid esters of 3-monochloropropane-1,2-diol.  

PubMed

A total of 290 individual food samples were collected in Hong Kong, China, for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters analysis. Most samples were processed food and in ready-to-eat form. The results show that the levels of 3-MCPD fatty acid esters were high in biscuits, fats and oils, snacks and Chinese pastry with mean bound 3-MCPD levels of 440, 390, 270 and 270 ?g kg?¹, respectively. The dietary exposures to bound 3-MCPD of average and high adult consumers were estimated to be 0.20 and 0.53 ?g kg bw?¹ day?¹, respectively. The primary toxicological concern of 3-MCPD fatty acid esters is its potential to release 3-MCPD in vivo during digestion in the gastrointestinal tract. 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats. Assuming that 100% of the 3-MCPD was released from 3-MCPD fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10% and 26% of the provisional maximum tolerable daily intake (PMTDI) of 3-MCPD established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2 ?g kg bw?¹ day?¹), respectively. The results suggest that both average and high adult consumers are unlikely to experience major toxicological effects of 3-MCPD. PMID:23862736

Chung, H Y; Chung, Stephen W C; Chan, B T P; Ho, Yuk Yin; Xiao, Ying

2013-01-01

421

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...

422

Fatty acid methyl esters (FAMEs) from castor oil: Production process assessment and synergistic effects in its properties  

Microsoft Academic Search

Fatty acid methyl esters (FAMEs) from castor oil have been synthesized by methanolysis catalyzed by sodium methoxide and the optimal transesterification conditions have been found. However, some properties of the castor FAME render it unsuitable in pure state for its direct use as fuel in internal combustion engines. Thus, blends with reference diesel have been prepared and their properties have

Laureano Canoira; Juan Garcia Galean; Ramon Alcantara; Magin Lapuerta; Reyes Garcia-Contreras

423

The influence of molecular structure of fatty acid monoalkyl esters on diesel combustion  

SciTech Connect

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)

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

424

Fatty Acid Methyl Esters and Solutol HS 15 Confer Neuroprotection After Focal and Global Cerebral Ischemia  

PubMed Central

We previously showed that palmitic methyl ester (PAME) and stearic acid methyl ester (SAME) are simultaneously released from the sympathetic ganglion and PAME possesses potent vasodilatory properties which may be important in cerebral ischemia. Since PAME is a potent vasodilator simultaneously released with SAME, our hypothesis was that PAME/SAME confers neuroprotection in rat models of focal/global cerebral ischemia. We also examined the neuroprotective properties of Solutol HS15, a clinically approved excipient, because it possesses similar fatty acid compositions as PAME/SAME. Asphyxial cardiac arrest (ACA, 6min) was performed 30mins after PAME/SAME treatment (0.02mg/kg, IV). Solutol HS15 (2 ml/kg, IP) was injected chronically for 14 days (once daily). Histopathology of hippocampal CA1 neurons was assessed 7 days after ACA. For focal ischemia experiments, PAME, SAME, or Solutol HS15 was administered following reperfusion after 2 hrs of middle cerebral artery occlusion (MCAO). 2,3,5-triphenyltetrazolium staining of the brain was performed 24hrs after MCAO and the infarct volume was quantified. Following ACA, the number of surviving hippocampal neurons was enhanced by PAME (68%), SAME (69%), and Solutol HS15 (68%)-treated rats as compared to ACA only-treated groups. Infarct volume was decreased by PAME (83%), SAME (68%), and Solutol HS15 (78%) as compared to saline (vehicle) in MCAO-treated animals. PAME, SAME, and Solutol HS15 provide robust neuroprotection in both paradigms of ischemia. This may prove therapeutically beneficial since Solutol HS15 is already administered as a solublizing agent to patients. With proper timing and dosage, administration of Solutol HS15 and PAME/SAME can be an effective therapy against cerebral ischemia. PMID:24323706

Lin, Hung Wen; Saul, Isabel; Gresia, Victoria L.; Neumann, Jake T.; Dave, Kunjan R.; Perez-Pinzon, Miguel A.

2013-01-01

425

Gene cloning and characterization of ?-amino acid ester acyl transferase in Empedobacter brevis ATCC14234 and Sphingobacterium siyangensis AJ2458.  

PubMed

The gene encoding ?-amino acid ester acyl transferase (AET), the enzyme that catalyzes the peptide-forming reaction from amino acid methyl esters and amino acids, was cloned from Empedobacter brevis ATCC14234 and Sphingobacterium siyangensis AJ2458 and expressed in Escherichia coli. This is the first report on the aet gene. It encodes a polypeptide composed of 616 (ATCC14234) and 619 (AJ2458) amino acids residues. The V(max) values of these recombinant enzymes during the catalysis of L-alanyl-L-glutamine formation from L-alanine methylester and L-glutamine were 1,010 U/mg (ATCC14234) and 1,154 U/mg (AJ2458). An amino acid sequence similarity search revealed 35% (ATCC14234) and 36% (AJ2458) identity with an ?-amino acid ester hydrolase from Acetobacter pasteurianus, which contains an active-site serine in the consensus serine enzyme motif, GxSYxG. In the deduced amino acid sequences of AET from both bacteria, the GxSYxG motif was conserved, suggesting that AET is a serine enzyme. PMID:22056425

Abe, Isao; Hara, Seiichi; Yokozeki, Kenzo

2011-01-01

426

Spherical Oligo-Silicic Acid SOSA Disclosed as Possible Endogenous Digitalis-Like Factor  

PubMed Central

The Na+/K+-ATPase is a membrane ion-transporter protein, specifically inhibited by digitalis glycosides used in cardiac therapy. The existence in mammals of some endogenous digitalis-like factors (EDLFs) as presumed ATPase ligands is generally accepted. But the chemical structure of these factors remained elusive because no weighable amounts of pure EDLFs have been isolated. Recent high-resolution crystal structure data of Na+/K+-ATPase have located the hydrophobic binding pocket of the steroid glycoside ouabain. It remained uncertain if the EDLF are targeting this steroid-receptor or another specific binding site(s). Our recently disclosed spherical oligo-silicic acids (SOSA) fulfill the main criteria to be identified with the presumed EDL factors. SOSA was found as a very potent inhibitor of the Na+/K+-ATPase, Ca2+-ATPase, H+/K+-ATPase, and of K-dp-ATPase, with IC50 values between 0.2 and 0.5??g/mL. These findings are even more astonishing while so far, neither monosilicic acid nor its poly-condensed forms have been remarked biologically active. With the diameter ? between 1 and 3?nm, SOSA still belong to molecular species definitely smaller than silica nano-particles with ??>?5?nm. In SOSA molecules, almost all Si-OH bonds are displayed on the external shell, which facilitates the binding to hydrophilic ATPase domains. SOSA is stable for long term in solution but is sensitive to freeze-drying, which could explain the failure of countless attempts to isolate pure EDLF. There is a strong resemblance between SOSA and vanadates, the previously known general inhibitors of P-type ATPases. SOSA may be generated endogenously by spherical oligomerization of the ubiquitously present monosilicic acid in animal fluids. The structure of SOSA is sensitive to the concentration of Na+, K+, Ca2+, Mg2+, and other ions suggesting a presumably archaic mechanism for the regulation of the ATPase pumps. PMID:25667581

Kerek, Franz; Voicu, Victor A.

2015-01-01

427

Synthesis of medium chain length fatty acid ethyl esters in engineered Escherichia coli using endogenously produced medium chain fatty acids.  

PubMed

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

Fan, Liping; Liu, Junfeng; Nie, Kaili; Liu, Luo; Wang, Fang; Tan, Tianwei; Deng, Li

2013-07-10

428

Preparation of radiolabeled tetracosa mono- and dienoic acid methyl esters from rat erythrocyte lipids by thin layer chromatography  

Microsoft Academic Search

An easy method of obtaining pure fatty acid methyl esters (FAME) of tetracosa mono- and dienoic acids (24?1, 24?2) using thin\\u000a layer chromatography (TLC) is described. The total lipids isolated from rat erythrocytes were treated with methanolic-NaOH.\\u000a Sphingomyelin was unaffected by this treatment and was separated from FAME of glycerolipids and cholesterol by TLC. FAME of\\u000a sphingomyelin were then prepared

G. Ananda Rao; Robert L. Kilpatrick; Steven C. Goheen; Edward C. Larkin

1980-01-01

429

Metal Extraction by Silyl?Substituted Diphosphonic Acids. III. Ester Group Substituent Effects on Phosphoryl Oxygen Basicity  

Microsoft Academic Search

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

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

2003-01-01

430

Zirconium-mediated intramolecular ester transfer reaction: synthesis of alpha-substituted gamma-aminobutyric acid (GABA) derivatives.  

PubMed

[reaction: see text]. The zirconium-mediated intramolecular ester transfer reaction of N-alkenyl carbamate derivatives proceeded to give alpha-substituted gamma-aminobutyric acid (GABA) derivatives in good to excellent yields. Quenching experiments of the reaction mixture with iodine or O2 indicated the presence of a cyclopropane intermediate. The resulting iodide was converted to 2-substituted pyrrolidine-3-carboxylate and/or alpha-alkylidene-gamma-aminobutyric acid derivatives in a stereospecific manner. PMID:11975613

Ito, Hisanaka; Omodera, Katsunori; Takigawa, Yasushi; Taguchi, Takeo

2002-05-01

431

Analysis of hydroxy fatty acids as pentafluorobenzyl ester, trimethylsilyl ether derivatives by electron ionization gas chromatography\\/mass spectrometry  

Microsoft Academic Search

Electron ionization (EI) gas chromatography\\/mass spectrometry (GC\\/MS) analysis of pentafluorobenzyl ester-trimethyl sllyl\\u000a ether (PFB-TMS) derivatives of hydroxy-subshtuted fatty acids provides structural information comparable to that obtained\\u000a in analysis of methyl ester-trimethyl silyl ether (Me-TMS) derivatives. Use of this derivative eliminates the need to prepare\\u000a two separate derivatives, the PFB-TMS derivative for molecular weight determination by electron capture ionization (negative\\u000a ions)

Pat Wheelan; Joseph A. Zirrolli; Robert C. Murphy

1995-01-01

432

Effects of triolein or oleic acid on lymphatic recovery of docosahexaenoic acid given as ethyl ester and their intramolecular distribution in lymph triglyceride of rats  

Microsoft Academic Search

Effects of oleic acid or triolein on lymphatic recovery of docosahexaenoic acid (DHA) given as an ethyl ester were examined\\u000a in rats with cannulated thoracic ducts. Lymphatic recovery of ethyl DHA given with oleic acid or triolein was significantly\\u000a higher than in rats given ethyl DHA alone. DHA distrbuted almost exclusively at the 1-and 3-position of triglyceride in lymph\\u000a collected

Ikuo Ikeda; Hiroko Yoshida; Katsumi Imaizumi

1997-01-01

433

Fatty acids of Thespesia populnea: Mass spectrometry of picolinyl esters of cyclopropene fatty acids  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thespesia populnea belongs to the plant family of Malvaceae which contain cyclopropane and cyclopropene fatty acids. However, previous literature reports vary regarding the content of these compounds in Thespesia populnea seed oil. In this work, the content of malvalic acid (8,9-methylene-9-heptade...

434

Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 19: Condensation of phthalic and substituted phthalic anhydrides with benzoylacetic ester  

NASA Technical Reports Server (NTRS)

Phthalylbenzoylacetic ester and its nitro and halogen derivatives were prepared through condensation of phthalic anhydride, nitrophthalic anhydride, and phthalic halide anhydride with benzoylacetic ester in a solution of acetic anhydride and triethylamine. The condensation of hemipinic acid anhydride proceeds similarly, but under more drastic conditions. Derivatives of indan-1,3-dione are also formed, with a small yield, in the reaction of nitrophthalic anhydrides with benzoylacetic ester in the presence of increased quantities of triethylamine.

Rotberg, Y. T.; Oshkaya, V. P.

1985-01-01

435

Stimulation of Expression of a Silica-Induced Protein (Sip) in Thermus thermophilus by Supersaturated Silicic Acid?  

PubMed Central

The effects of silicic acid on the growth of Thermus thermophilus TMY, an extreme thermophile isolated from a siliceous deposit formed from geothermal water at a geothermal power plant in Japan, were examined at 75°C. At concentrations higher than the solubility of amorphous silica (400 to 700 ppm SiO2), a silica-induced protein (Sip) was isolated from the cell envelope fraction of log-phase TMY cells grown in the presence of supersaturated silicic acid. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the molecular mass and pI of Sip to be about 35 kDa and 9.5, respectively. Induction of Sip expression occurred within 1 h after the addition of a supersaturating concentration of silicic acid to TM broth. Expression of Sip-like proteins was also observed in other thermophiles, including T. thermophilus HB8 and Thermus aquaticus YT-1. The amino acid sequence of Sip was similar to that of the predicted solute-binding protein of the Fe3+ ABC transporter in T. thermophilus HB8 (locus tag, TTHA1628; GenBank accession no. NC_006461; GeneID, 3169376). The sip gene (987-bp) product showed 87% identity with the TTHA1628 product and the presumed Fe3+-binding protein of T. thermophilus HB27 (locus tag TTC1264; GenBank accession no. NC_005835; GeneID, 2774619). Within the genome, sip is situated as a component of the Fbp-type ABC transporter operon, which contains a palindromic structure immediately downstream of sip. This structure is conserved in other T. thermophilus genomes and may function as a terminator that causes definitive Sip expression in response to silica stress. PMID:19233950

Doi, Katsumi; Fujino, Yasuhiro; Inagaki, Fumio; Kawatsu, Ryouichi; Tahara, Miki; Ohshima, Toshihisa; Okaue, Yoshihiro; Yokoyama, Takushi; Iwai, Satoru; Ogata, Seiya

2009-01-01

436

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

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

W. N. Ratnayake; R. G. Ackman

1979-01-01

437

Olfactory Perception of Oviposition-Deterring Fatty Acids and Their Methyl Esters by the Asian Corn Borer, Ostrinia furnacalis  

PubMed Central

Olfactory perception of myristic, palmitic, stearic and oleic acids and their corresponding methyl esters by Asian corn borer moths, Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae) was investigated. It was found that mated females with both antennae amputated, in contrast to intact females and females with one antenna removed, could not discriminate between simultaneously provided control filter papers and filters treated with a blend of oviposition-deterring fatty acids. Oviposition by mated females exhibited a very marked periodicity, with all egg masses deposited during the scotophase and most egg masses laid before midnight. According to the peak and trough period of oviposition, electroantennogram (EAG) responses from both mated females and males to the four fatty acids and four methyl esters were tested within two two-hour periods from 3 to 5 hours after the start of darkness and from 1 to 3 hours after light onset, respectively. Significant EAG responses above solvent and background were elicited by all test chemicals from females, and by most of the test compounds from males. EAG values of all test chemicals from mated females were not statistically different between the two test periods except for methyl myristate. Conversely, EAG responses from mated males to myristic acid, stearic acid and their methyl esters significantly differed between the two test periods. PMID:20053122

Guo, Lei; Qing Li, Guo

2009-01-01

438

Evaluation of the retention pattern on ionic liquid columns for gas chromatographic analyses of fatty acid methyl esters.  

PubMed

Fatty acid methyl esters from marine sources were analyzed by gas chromatography-mass spectrometry on three ionic liquid columns, SLB-IL61, SLB-IL82 and SLB-IL100 (Supelco). Retention indices (equivalent chain lengths) are reported for more than 100 compounds and the overlap patterns are evaluated from these data. The influence of chromatographic conditions on the retention indices of unsaturated fatty acid methyl esters is also evaluated. Compared to typical alternative phases the retention patterns on all three columns are highly dependent on the conditions. The SLB-IL61 phase had overlaps between nutritionally important fatty acids that could not be resolved by changing the chromatographic conditions. This column is therefore regarded as unsuitable for clinical and nutritional studies of the fatty acid composition, but similar overlaps may be avoided on IL82 and IL100. On all three columns double bonds close to the carboxyl group in the analytes contribute with limited retention, which makes it challenging to predict the retention of polyunsaturated fatty acid methyl esters. PMID:24873965

Lin, Chen-Chen; Wasta, Ziar; Mjøs, Svein A

2014-07-11

439

In vitro digestion of citric acid esters of mono- and diglycerides (CITREM) and CITREM-containing infant formula/emulsions.  

PubMed

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

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

440

Concurrent release of admixed antimicrobials and salicylic acid from salicylate-based poly(anhydride-esters).  

PubMed

A polymer blend consisting of antimicrobials (chlorhexidine, clindamycin, and minocycline) physically admixed at 10% by weight into a salicylic acid-based poly (anhydride-ester) (SA-based PAE) was developed as an adjunct treatment for periodontal disease. The SA-based PAE/antimicrobial blends were characterized by multiple methods, including contact angle measurements and differential scanning calorimetry. Static contact angle measurements showed no significant differences in hydrophobicity between the polymer and antimicrobial matrix surfaces. Notable decreases in the polymer glass transition temperature (T(g)) and the antimicrobials' melting points (T(m)) were observed indicating that the antimicrobials act as plasticizers within the polymer matrix. In vitro drug release of salicylic acid from the polymer matrix and for each physically admixed antimicrobial was concurrently monitored by high pressure liquid chromatography during the course of polymer degradation and erosion. Although the polymer/antimicrobial blends were immiscible, the initial 24 h of drug release correlated to the erosion profiles. The SA-based PAE/antimicrobial blends are being investigated as an improvement on current localized drug therapies used to treat periodontal disease. PMID:19180627

Johnson, Michelle L; Uhrich, Kathryn E

2009-12-01

441

Concurrent release of admixed antimicrobials and salicylic acid from salicylate-based poly(anhydride-esters)  

PubMed Central

A polymer blend consisting of antimicrobials (chlorhexidine, clindamycin, and minocycline) physically admixed at 10% by weight into a salicylic acid-based poly (anhydride-ester) (SA-based PAE) was developed as an adjunct treatment for periodontal disease. The SA-based PAE/antimicrobial blends were characterized by multiple methods, including contact angle measurements and differential scanning calorimetry. Static contact angle measurements showed no significant differences in hydrophobicity between the polymer and antimicrobial matrix surfaces. Notable decreases in the polymer glass transition temperature (Tg) and the antimicrobials' melting points (Tm) were observed indicating that the antimicrobials act as plasticizers within the polymer matrix. In vitro drug release of salicylic acid from the polymer matrix and for each physically admixed antimicrobial was concurrently monitored by high pressure liquid chromatography during the course of polymer degradation and erosion. Although the polymer/antimicrobial blends were immiscible, the initial 24 h of drug release correlated to the erosion profiles. The SA-based PAE/antimicrobial blends are being investigated as an improvement on current localized drug therapies used to treat periodontal disease. PMID:19180627

Johnson, Michelle L.; Uhrich, Kathryn E.

2008-01-01

442

Regulatory effects of caffeic Acid phenethyl ester on neuroinflammation in microglial cells.  

PubMed

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

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

443

Relative oral bioavailability of 3-MCPD from 3-MCPD fatty acid esters in rats.  

PubMed

In order to quantify the relative oral bioavailability of 3-chloropropane-1,2-diol (3-MCPD) from 3-MCPD fatty acid diesters in vivo, 1,2-dipalmitoyl-3-chloropropane-1,2-diol (3-MCPD diester) and 3-MCPD were orally applied to rats in equimolar doses. In both cases, the time courses of 3-MCPD concentrations were measured in blood, various organs, tissues and intestinal luminal contents. The results show that 3-MCPD is released by enzymatic hydrolysis from the 3-MCPD diester in the gastrointestinal tract and distributed to blood, organs and tissues. Based on the measurements in blood, the areas under the curve (AUC) for 3-MCPD were calculated. By comparing both AUC, the relative amount of 3-MCPD bioavailable from the 3-MCPD diester was calculated to be 86 % on average of the amount bioavailable following administration of 3-MCPD. In view of limited experimental data, it is justified for the purpose of risk assessment to assume complete hydrolysis of the diesters in the gastro-intestinal tract. Therefore, assessment of the extent of exposure to 3-MCPD released from its fatty acid esters should be performed in the same way as exposure to the same molar quantity of 3-MCPD. PMID:23229518

Abraham, Klaus; Appel, Klaus E; Berger-Preiss, Edith; Apel, Elisabeth; Gerling, Susanne; Mielke, Hans; Creutzenberg, Otto; Lampen, Alfonso

2013-04-01

444

Iron and silicic acid concentrations regulate Si uptake north and south of the Polar Frontal Zone in the Pacific Sector of the Southern Ocean  

Microsoft Academic Search

We investigated the relative roles of Fe and silicic acid availabilities in regulating Si uptake rates across the Polar Frontal Zone in the Pacific Sector of the Southern Ocean (59–68°S, 170°W) during the US JGOFS Antarctic Environment Southern Ocean Process Study (AESOPS). Meridional gradients in silicic acid concentration ([Si(OH)4]) of about 0.25–0.56?Mkm?1 were observed in this area during austral spring

Valerie M. Franck; Mark A Brzezinski; Kenneth H Coale; David M Nelson

2000-01-01

445

Prop2-ynyl as a protective group for carboxylic acids: a mild method for the highly selective deprotection of prop-2-ynyl esters using tetrathiomolybdate  

Microsoft Academic Search

It is shown that prop-2-ynyl esters are useful protecting groups for carboxylic acids and that they are selectively deprotected in the presence of other esters on treatment with tetrathiomolybdate under mild conditions. There is a constant search for new, easy to introduce and selectively removable protecting groups in organic synthesis. Over the years a number of protective groups have been

Palanichamy Ilankumaran; N. Manoj; Srinivasan Chandrasekaran

1996-01-01

446

A new ferulic acid ester, a new ellagic acid derivative, and other constituents from pachycentria formosana: effects on neutrophil pro-inflammatory responses.  

PubMed

A new ferulic acid ester derivative, tetracosane-1,24-diyl di[(Z)-ferulate] (1), and a new ellagic acid derivative, 3,4?:?3',4'-bis(O,O-methylene)ellagic acid (2), have been isolated from leaves and twigs of Pachycentria formosana, together with eight known compounds. Their structures were determined by in-depth spectroscopic and mass-spectrometric analyses. Among the isolated compounds, oleanolic acid (6), ursolic acid acetate (7), and 3-epibetulinic acid (9) exhibited potent inhibition (IC(50) values ? 21.8 ?M) of O?(-) generation by human neutrophils in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). In addition, oleanolic acid (6), 3-O-[(E)-feruloyl]ursolic acid (8), 3-epibetulinic acid (9), and lawsonic acid (10) also inhibited fMLP/CB-induced elastase release with IC(50) values ? 18.6 ?M. PMID:21922659

Cho, Jui-Ying; Lee, Tzong-Huei; Hwang, Tsong-Long; Yang, Sheng-Zehn; Chen, Ih-Sheng; Chou, Tsung-Hsien; Sung, Ping-Jyun; Chen, Jih-Jung

2011-09-01

447

Sucrose esters of carboxylic acids in glandular trichomes ofSolanum berthaultii deter settling and probing by green peach aphid.  

PubMed

Removal of type B trichome exudate fromSolanum berthaultii leaflets leads to a decrease in tarsal gumming and mortality and an increase in feeding by the green peach aphid,Myzus persicae. Type B trichome exudate of theS. berthaultii accession PI 473331 is composed of a complex of 3',3,4,6-tetra-O-acyl sucroses containing primarily short-chain branched carboxylic acids. The acyl constituents are primarily derived from 2-methylpropanoic, 2-methylbutyric, and 8-methylnonanoic acids but constituents derived fromn-decanoic and dodecanoic acids are also present. Sucrose esters inhibit settling and probing by aphids in glass feeding cages. PMID:24263505

Neal, J J; Tingey, W M; Steffens, J C

1990-02-01

448

Selective depressions of surface silicic acid within cyclonic mesoscale eddies in the oligotrophic western North Pacific  

NASA Astrophysics Data System (ADS)

To reveal spatial dynamics of silicic acid [Si(OH)4] in the poorly sampled oligotrophic western North Pacific, we investigated the surface distribution of Si(OH)4 and associated biogeochemical parameters by using an underway survey system with a highly sensitive nutrient analyzer along the 138°E transect (between 30 and 34°N) and the 155°E transect (between 10 and 35°N) during the summers of 2007 and 2008. Surface Si(OH)4 concentrations ranged from the detection limit (11 nmol L-1) to 2462 nmol L-1. High Si(OH)4 concentrations (>1000 nmol L-1) and dynamic fluctuations were generally observed north of 23°N, while consistently stable low concentrations of 415-751 nmol L-1 were observed south of 23°N. Surface nitrate+nitrite (N+N) and phosphate (PO43-) were typically depleted to <20 nmol L-1, except for PO43- in the area south of 16°N. The majority of the study area was characterized by high-Si(OH)4 and low-N+N and PO43-. However, submesoscale/mesoscale depressions of Si(OH)4 were locally observed in the cyclonic eddy fields north of 23°N. Among a total of six Si(OH)4 depressions within the eddies, a complete Si(OH)4 depletion (<11 nmol L-1) was observed on the cyclonic side near the Kuroshio axis (33.1°N, 138°E). This depletion was closely coupled with a diatom bloom, suggesting that Si(OH)4 was exhausted by diatoms. All of the Si(OH)4 depressions were selective and not accompanied by local depressions of N+N and PO43-. This unique phenomenon might be driven by biogeochemical processes such as selective Si export (Si pump), anomalous Si uptake associated with diatom physiology, and/or Si uptake supported by N2 fixation.

Hashihama, Fuminori; Kanda, Jota; Maeda, Yousaku; Ogawa, Hiroshi; Furuya, Ken

2014-08-01

449

Determination of selected fate and aquatic toxicity characteristics of acrylic acid and a series of acrylic esters.  

PubMed

Acrylic acid, methyl acrylate, ethyl acrylate, and butyl acrylate are commercially important and widely used materials. This paper reports the results of a series of fate and aquatic toxicity studies. The mobility in soil of acrylic acid and its esters ranged from 'medium' to 'very high'. Calculated bioconcentration factors ranged from 1 to 37, suggesting a low bioconcentration potential. Acrylic acid and methyl acrylate showed limited biodegradability in the five day biochemical oxygen demand (BOD5) test, while ethyl acrylate and butyl acrylate were degraded easily (77% and 56%, respectively). Using the OECD method 301D 28-d closed bottle test, degradability for acrylic acid was 81% at 28 days, while the acrylic esters ranged from 57% to 60%. Acrylic acid degraded rapidly to carbon dioxide in soil (t1/2 < 1 day). Toxicity tests were conducted using freshwater and marine fish, invertebrates, and algae. Acrylic acid effect concentrations for fish and invertebrates ranged from 27 to 236 mg/l. Effect concentrations (LC50 or EC50) for fish and invertebrates using methyl acrylate, ethyl acrylate, and butyl acrylate ranged from 1.1 to 8.2 mg/l. The chronic MATC for acrylic acid with Daphnia magna was 27 mg/l based on length and young produced per adult reproduction day and for ethyl acrylate was 0.29 mg/l based on both the reproductive and growth endpoints. Overall these studies show that acrylic acid and the acrylic esters studied can rapidly biodegrade, have a low potential for persistence or bioaccumulation in the environment, and have low to moderate toxicity. PMID:10665442

Staples, C A; Murphy, S R; McLaughlin, J E; Leung, H W; Cascieri, T C; Farr, C H

2000-01-01

450

Effect of n-3 fatty acid ethyl ester supplementation on fatty acid composition of the single platelet phospholipids and on platelet functions  

Microsoft Academic Search

Twenty healthy male volunteers were randomly assigned to receive either four 1-g capsules of n-3 polyunsaturated fatty acids (PUFA) ethyl esters or four 1-g capsules of olive oil (as placebo) for a period of 4 months, followed by a 3-month wash-out period. Fatty acids of platelet phospholipid fractions, platelet aggregation, and thromboxane B2 (TXB2) formation were analyzed at 0, 2,

Domenico Prisco; Monica Filippini; Isa Francalanci; Rita Paniccia; Gian Franco Gensini; Gian Gastone Neri Serneri

1995-01-01

451

Studies on extraction behaviour of molybdenum (VI) from acidic radioactive waste using 2(ethylhexyl) phosphonic acids, mono 2(ethylhexyl) ester (PC88A)\\/ n -dodecane  

Microsoft Academic Search

This paper describes the studies on the extraction of molybdenum (VI) from aqueous nitric acid medium by (2-ethylhexyl) phosphonic\\u000a acid, mono (2-ethylhexyl) ester (PC-88A). The extraction affecting parameters such as concentration of HNO3 in aqueous feed, effect of concentration of extractants, effect of diluents, and molybdenum concentration in the aqueous\\u000a phase are investigated to optimize the extraction conditions for the

S. K. Pathak; Suman Kumar Singh; Arvind Mahtele; S. C. Tripathi

2010-01-01

452

Synthesis and Antioxidant Evaluation of Enantiomerically Pure Bis-(1,2,3-triazolylmethyl)amino Esters from Modified ?-Amino Acids  

PubMed Central

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

Sarmiento-Sánchez, Juan I.; Ochoa-Terán, Adrián; Rivero, Ignacio A.

2014-01-01

453

Simultaneous production of fatty acid methyl esters and diglycerides by four recombinant Candida rugosa lipase's isozymes.  

PubMed

In this study, the catalytic efficiency of four recombinant CRL (Candida rugosa lipase) isozymes (LIP1-LIP4) towards the production of fatty acid methyl ester (FAME) was compared and evaluated as an alternative green method for industrial applications. The results indicated that the recombinant C. rugosa LIP1 enzyme exhibited the highest catalytic efficiency for FAME production compared to the recombinant C. rugosa LIP2-LIP4 enzymes. The optimal conditions were as follows: pH 7.0, methanol/soybean oil molar ratio: 3/1, enzyme amount: 2U (1.6 ?L), reaction temperature: 20°C, 22 h of reaction time, and 3 times of methanol addition (1 mol/6h), and resulted in 61.5 ± 1.5 wt.% of FAME conversion. The reaction product contained also 10 wt.% of DAG with a ratio of 1,3-DAG to 1,2-DAG of approximately 4:6, and can be potentially used in industrial applications as a food emulsifier. PMID:24594166

Chang, Shu-Wei; Huang, Myron; Hsieh, Yu-Hsun; Luo, Ying-Ting; Wu, Tsung-Ta; Tsai, Chia-Wen; Chen, Chin-Shuh; Shaw, Jei-Fu

2014-07-15

454

Electron Affinity of Phenyl-C61-Butyric Acid Methyl Ester (PCBM)  

SciTech Connect

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.

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

455

Caffeic acid phenethyl ester improves burn healing in rats through anti-inflammatory and antioxidant effects.  

PubMed

Although caffeic acid phenethyl ester (CAPE) has beneficial properties, its anti-inflammatory and antioxidant effects on healing burn injury have not been investigated as yet. Female Wistar rats were divided in two groups: burn and burn + CAPE. A scald injury (burn) was performed. CAPE treatment (10 µmol kg) began immediately after the burn and lasted for 14 days. Euthanasia was performed 14 or 70 days after burning. Seven, 21, and 70 days after burning, burn + CAPE group presented smaller wound area. Increase in reepithelialization was observed in burn + CAPE group 28 and 63 days after burning. Fourteen days after wounding, burn + CAPE group presented diminished myeloperoxidase activity and nitrite levels, reduced CD68 and platelet endothelial cell adhesion molecule 1 protein expression, and less oxidative damage (decrease in malondialdehyde (MDA) and carbonyl levels in plasma and lesion extracts). Seventy days after burning, the amount of myofibroblasts and macrophages (CD68 positive) was decreased and the amount of hydroxyproline was increased in burn + CAPE group. Treatment with CAPE improved burn wound healing, showing decrease in inflammatory parameters and in oxidative damage. PMID:23511289

dos Santos, Jeanine Salles; Monte-Alto-Costa, Andréa

2013-01-01

456

Production of fatty acid butyl esters using the low cost naturally immobilized Carica papaya lipase.  

PubMed

In this work, the low cost naturally immobilized Carica papaya lipase (CPL) was investigated for production of fatty acid butyl esters (FABE) to fulfill the aim of reducing the lipase cost in the enzymatic butyl-biodiesel process. The CPL showed specificities to different alcohol acyl acceptors. Alcohols with more than three carbon atoms did not have negative effects on the CPL activity. The CPL catalyzed butanolysis for FABE production was systematically investigated. The reaction solvent, alcohol/oil molar ratio, enzyme amount, reaction temperature, and water activity all affected the butanolysis process. Under the optimized conditions, the highest conversion of 96% could be attained in 24 h. These optimal conditions were further applied to CPL catalyzed butanolysis of other vegetable oils. All of them showed very high conversion. The CPL packed-bed reactor was further developed, and could be operated continuously for more than 150 h. All of these results showed that the low cost Carica papaya lipase can be used as a promising lipase for biodiesel production. PMID:24954104

Su, Erzheng; Wei, Dongzhi

2014-07-01

457

Caffeic acid phenethyl ester (CAPE), an active component of propolis, inhibits Helicobacter pylori peptide deformylase activity.  

PubMed

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

Cui, Kunqiang; Lu, Weiqiang; Zhu, Lili; Shen, Xu; Huang, Jin

2013-05-31

458

Negative polarity of phenyl-C61 butyric acid methyl ester adjacent to donor macromolecule domains  

NASA Astrophysics Data System (ADS)

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.

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

459

Utilization of rapeseed pellet from fatty acid methyl esters production as an energy source.  

PubMed

Rapeseed pellet - crushed seed residue from oil extraction is a by-product of fatty acid methyl esters production process. As other types of biomass, it can either be burned directly in furnaces or processed to increase its energetic value. Biomass is renewable, abundant and has domestic usage; the sources ofbiomass can help the world reduce its dependence on petroleum products, fossil coal and natural gas. Energetically effective utilization of rapeseed pellet could substantially improve the economic balance of an individual household in which biodiesel for fulfilling the producer's own energetic demand is obtained. In this article, the experimental results of combusting rapeseed pellet in a calorimeter, combustion in a boiler heater and the analysis of the emissions level of different pollutants in exhaust fumes during different stages of biomass boiler operation are presented. It has been proved that the pellet, a by-product of biodiesel production, is not only a valuable substitute of animal fodder, but also an excellent renewable and environmentally friendly energy source, viable for use in household tap water heating installations. PMID:24600857

Ciunel, Krzysztof; Klugmann-Radziemska, Ewa

2014-01-01

460

S-(?)-10,11-Dihydroxyfarnesoic Acid Methyl Ester Inhibits Melanin Synthesis in Murine Melanocyte Cells  

PubMed Central

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

Baek, Seung-Hwa; Ahn, Jun-Won; Nam, Sung-Hee; Yoon, Cheol-Sik; Shin, Jae-Cheon; Lee, Sang-Han

2014-01-01

461

Antimicrobial effect of para-alkoxyphenylcarbamic acid esters containing substituted N-phenylpiperazine moiety  

PubMed Central

In current research, nine basic esters of para-alkoxyphenylcarbamic acid with incorporated 4-(4-fluoro-/3-trifluoromethylphenyl)piperazin-1-yl fragment, 6i–6m and 8f–8i, were screened for their in vitro antimicrobial activity against Candida albicans, Staphylococcus aureus and Escherichia coli, respectively. Taking into account the minimum inhibitory concentration assay (MIC), as the most active against given yeast was evaluated 8i (MIC = 0.20 mg/mL), the most lipophilic structure containing para-butoxy and trifluoromethyl substituents. Investigating the efficiency of the compounds bearing only a single atom of fluorine and appropriate para-alkoxy side chain against Candida albicans, the cut-off effect was observed. From evaluated homological series, the maximum of the effectiveness was noticed for the stucture 6 k (MIC = 0.39 mg/mL), containing para-propoxy group attached to phenylcarbamoyloxy fragment, beyond which the compounds ceased to be active. On the contrary, all the tested molecules were against Staphylococcus aureus and Escherichia coli (MICs > 1.00 mg/mL) practically inactive. PMID:24294237

Malík, Ivan; Bukovský, Marián; Andriamainty, Fils; Gališinová, Jana

2013-01-01

462

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

PubMed

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

Chi, Jie

2009-09-01

463

Fumaric Acid Esters Stimulate Astrocytic VEGF Expression through HIF-1? and Nrf2  

PubMed Central

Fumaric acid esters (FAE) are oral analogs of fumarate that have recently been shown to decrease relapse rate and disease progression in multiple sclerosis (MS), prompting to investigate their protective potential in other neurological diseases such as amyotrophic lateral sclerosis (ALS). Despite efficacy in MS, mechanisms of action of FAEs are still largely unknown. FAEs are known to activate the transcription factor Nrf2 and downstream anti-oxidant responses through the succination of Nrf2 inhibitor KEAP1. However, fumarate is also a known inhibitor of prolyl-hydroxylases domain enzymes (PhD), and PhD inhibition might lead to stabilization of the HIF-1? transcription factor under normoxic conditions and subsequent activation of a pseudo hypoxic response. Whether Nrf2 activation is associated with HIF-1? stabilization in response to FAEs in cell types relevant to MS or ALS remains unknown. Here, we show that FAEs elicit HIF-1? accumulation, and VEGF release as its expected consequence, in astrocytes but not in other cell types of the central nervous system. Reporter assays demonstrated that increased astrocytic VEGF release in response to FAEs was dependent upon both HIF-1? and Nrf2 activation. Last, astrocytes of transgenic mice expressing SOD1(G93A), an animal model of ALS, displayed reduced VEGF release in response to FAEs. These studies show that FAEs elicit different signaling pathways in cell types from the central nervous system, in particular a pseudo-hypoxic response in astrocytes. Disease relevant mutations might affect this response. PMID:24098549

Wiesner, Diana; Merdian, Irma; Lewerenz, Jan; Ludolph, Albert C.; Dupuis, Luc; Witting, Anke

2013-01-01

464

Protective effects of caffeic acid phenethyl ester on iron-induced liver damage in rats.  

PubMed

Caffeic acid phenethyl ester (CAPE) is a natural product with potent anti-inflammatory, antitumor, and antioxidant activities, and attenuates inflammation and lipid peroxidation. The purpose of the present study was to investigate the effects of CAPE on iron-induced liver damage. Rats were divided into four groups and treated for 7 days with saline (control group), 10 micromol kg CAPE/day s.c. (CAPE group), 50 mg iron-dextran/kg i.p. (IRON group) and CAPE and iron at the same time (IRON+CAPE group). Seven days later, rats were killed and the livers were excised for biochemical analysis. The administration of IRON alone resulted in higher myeloperoxidase (MPO) activity and lipid peroxidation than in the control and CAPE treatment prevented the increase in MPO activity and malondialdeyde (MDA) level. No differences were observed in all four groups with regards to superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities. Our results collectively suggest that CAPE may be an available agent to protect the liver from injury via inhibition of MPO activity. PMID:20358346

Oktar, S; Yönden, Z; Aydin, M; Ilhan, S; Alçin, E; Oztürk, O H

2009-12-01

465

Effects of caffeic acid phenethyl ester on lipopolysaccharide-induced lung injury in rats.  

PubMed

Extracts of propolis, a natural beehive product, have been known for centuries to have a variety of beneficial medical properties, among which their anti-inflammatory effect is a major one. Caffeic acid phenethyl ester (CAPE), an active propolis component, has antimicrobial, anti-inflammatory, antioxidant, carcinostatic and immunomodulatory properties. In this study, we aimed to investigate the efficacy of CAPE in endotoxin-induced lung injury in rats. Lung injury was induced by a footpad injection of lipopolysaccharide (LPS). In the treatment group, 10 micromol kg(-1) CAPE was injected intraperitoneally immediately after LPS injection. At 24 h after LPS and/or CAPE injection, blood and lung tissue specimens were collected. MDA levels and MPO activity in serum and lung tissue, serum total antioxidant levels, lung tissue Na(+)/K(+) ATP-ase activity and histopathological evaluation were determined to assess the efficacy of CAPE treatment. CAPE was found to be efficient in reducing inflammation and lung tissue damage induced by LPS in rats. PMID:15953745

Koksel, Oguz; Ozdulger, Ali; Tamer, Lulufer; Cinel, Leyla; Ercil, Menderes; Degirmenci, Ulas; Unlu, Serdar; Kanik, Arzu

2006-01-01

466

Diffusion of cis-octadec-9-enoic acid propane-1,2,3-triyl ester (1); tridecane (2)  

NASA Astrophysics Data System (ADS)

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) cis-octadec-9-enoic acid propane-1,2,3-triyl ester; (2) tridecane

Winkelmann, J.

467

Lipase-catalyzed production of short-chain acids terpenyl esters of interest to the food industry  

Microsoft Academic Search

The production of low molecular weight esters as flavor compounds by biotechnological processes has a potential interest for\\u000a the food industry. The use of natural available substrates and enzymes is an essential part of the process design, because\\u000a the products may obtain natural label. In this study, direct esterification of citronellol and geraniol with short-chain fatty\\u000a acids catalyzed by free

Françoise Laboret; Robert Perraud

1999-01-01

468

Configuration and conformational equilibrium of (±)- trans-1-oxo-3-thiophen-2-yl-isochroman-4-carboxylic acid methyl ester  

Microsoft Academic Search

The X-ray analysis of 1-oxo-3-thiophen-2-yl-isochroman-4-carboxylic acid methyl ester 1 confirmed its trans-configuration and a conformation with diaxial H-3 and H-4 atoms in solid state. NMR experiments indicated that trans-1 exists in solution in both expected conformers. In CDCl3 and especially in CD3OD or DMSO, the conformational equilibrium is shifted towards the conformer with diequatorial H-3 and H-4, which was also

Milen G. Bogdanov; Iliya S. Todorov; Pavlina G. Manolova; Diana V. Cheshmedzhieva; Mariana D. Palamareva

2004-01-01

469

Changes in the molecular composition of ester-bound aliphatics with depth in an acid andic forest soil  

Microsoft Academic Search

Changes in the molecular composition of ester-linked aliphatic compounds with depth in an acid andic forest soil are studied. Thermally assisted hydrolysis and methylation (THM) using tetramethylammonium hydroxide in combination with gas chromatography\\/mass spectrometry revealed a dominance of cutin over suberin-derived THM products in the top 5 cm. From 5 to 20 cm, a strong increase in the contribution of

Derck Ferdinand Werner Naafs; Klaas G. J. Nierop; Pim F. van Bergen; Jan W. de Leeuw

2005-01-01

470

Changes in the molecular composition of ester-bound aliphatics with depth in an acid forest soil  

Microsoft Academic Search

Changes in the molecular composition of ester-linked aliphatic compounds with depth in an acid andic forest soil are studied. Thermally assisted hydrolysis and methylation (THM) using tetramethylammonium hydroxide in combination with gas chromatography\\/mass spectrometry revealed a dominance of cutin over suberin-derived THM products in the top 5 cm. From 5 to 20 cm, a strong increase in the contribution of

D. F. W. Naafs; K. G. J. Nierop; Bergen van P. F; Leeuw de J. W

2005-01-01

471

Sodium salts of alkyl esters of a -sulfo fatty acids. Wetting, lime soap dispersion, and related properties  

Microsoft Academic Search

A series of esters of the general formula RCH(SO3Na)-CO2R? of 14–19 carbon atoms prepared by the ?-sulfonation of propionic, butyric, pelargonic, lauric, myristic, palmitie, and\\u000a stearic acids and esterification with normal primary alcohols were compared for critical micelle concentration, surface and\\u000a interfacial tension, Ca++ stability, wetting properties, foam height, detergency, and lime soap dispersing properties. Comparison of position isomers\\u000a showed

A. J. Stirton; R. G. Bistline; J. K. Weil; Waldo C. Ault; E. W. Maurer

1962-01-01

472

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

Microsoft Academic Search

Hair analysis is a powerful tool for retrospective drug analysis. By determining the minor ethanol metabolites ethyl glucuronide\\u000a (EtG) and fatty acid ethyl esters (FAEEs) in hair, even a previous consumption of alcohol is detectable. However, previous\\u000a studies showed a lack of correlation if both parameters are determined simultaneously. A further study was conducted to confirm\\u000a or refute these results.

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

2011-01-01

473

Lipase-Catalyzed Synthesis of Saccharide–Fatty Acid Esters Using Suspensions of Saccharide Crystals in Solvent-Free Media  

Microsoft Academic Search

Saccharide–fatty acid esters, important biobased and biodegradable emulsifiers in foods, cosmetics, and pharmaceuticals, were\\u000a produced with high yields and productivity via immobilized Rhizomucor miehei lipase-catalyzed esterification in solvent-free systems at 65 °C. Preliminary experiments demonstrated high rates of reaction\\u000a occurred in the presence of acetone near or above its boiling point, due to the formation of 10–200 ?m suspensions of saccharide\\u000a particles.

Ran Ye; Sang-Hyun Pyo; Douglas G. Hayes

2010-01-01

474

Designs of Bioreactor Systems for Solvent-Free Lipase-Catalyzed Synthesis of Fructose–Oleic Acid Esters  

Microsoft Academic Search

Fructose–oleic acid esters, biodegradable, biocompatible and biobased surfactants and value-added products were synthesized\\u000a under solvent-free conditions at 65 °C in stirred-batch mode and using several different bioreactor systems. For a stirred-tank\\u000a bioreactor (STBR) using fed-batch fructose addition and 5.0 wt.% immobilized Rhizomucor miehei lipase (Lipozyme® IM, Novozymes, Franklinton, NC), the conversion yield was over 80%, and the initial rate of the reaction

Sang-Hyun Pyo; Douglas G. Hayes

2009-01-01

475

Synthesis and biological evaluation of new flavonoid fatty acid esters with anti-adipogenic and enhancing glucose consumption activities.  

PubMed

Oleoyl Formononetin (OF) has good weight loss activity and hypolipidemic activity, could improve insulin sensitivity and suppress adipogenesis. To acquire better biological activities, three series of flavonoid fatty acid esters were designed and synthesized by optimizing the structure of OF. Their bioactivities were assayed in vitro. Some of these novel compounds could effectively inhibit preadipocyte proliferation and adipogenesis. Moreover, they could enhance glucose consumption in adipocytes notably. PMID:21515060

Zhao, Wei; Sun, Jie; Xiang, Hua; Zeng, Yan-yan; Li, Xiao-bo; Xiao, Hong; Chen, De-ying; Ma, Ren-ling

2011-05-15

476

Inhibitors of mammalian melanocyte tyrosinase: in vitro comparisons of alkyl esters of gentisic acid with other putative inhibitors  

Microsoft Academic Search

To discover safe and effective topical skin-lightening agents, we have evaluated alkyl esters of the natural product gentisic acid (GA), which is related to our lead compound methyl gentisate (MG), and four putative tyrosinase inhibitors, utilizing mammalian melanocyte cell cultures and cell-free extracts. Desirable characteristics include the ability to inhibit melanogenesis in cells (ic50 < 100 ?g\\/mL) without cytotoxicity, preferably

Ernest V Curto; Cecil Kwong; Heino Hermersdörfer; Hansruedi Glatt; Chie Santis; Victoria Virador; Vincent J Hearing; Thomas P Dooley

1999-01-01

477

Preparation of C18-functionalized Fe3O4@SiO2 core-shell magnetic nanoparticles for extraction and determination of phthalic acid esters in Chinese herb preparations.  

PubMed

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

Guo, Bize; Ji, Shunli; Zhang, Feifang; Yang, Bingcheng; Gu, Jiangping; Liang, Xinmiao

2014-11-01

478

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

...FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.637 Methyl...cis-12-octadecadienoic acids). The food additive, methyl esters of...

2011-04-01

479

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

Code of Federal Regulations, 2012 CFR

...FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.637 Methyl...cis-12-octadecadienoic acids). The food additive, methyl esters of...

2012-04-01

480

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

Code of Federal Regulations, 2014 CFR

...FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.637 Methyl...cis-12-octadecadienoic acids). The food additive, methyl esters of...

2014-04-01

481

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

Code of Federal Regulations, 2013 CFR

...FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.637 Methyl...cis-12-octadecadienoic acids). The food additive, methyl esters of...

2013-04-01

482

Degradation of cyanidin-3-rutinoside and formation of protocatechuic acid methyl ester in methanol solution by gamma irradiation.  

PubMed

Anthocyanins are naturally occurring phenolic compounds having broad biological activities including anti-mutagenesis and anti-carcinogenesis. We studied the effects and the degradation mechanisms of the most common type of anthocyanins, cyanidin-3-rutinoside (cya-3-rut), by using gamma ray. Cya-3-rut in methanol (1mg/ml) was exposed to gamma-rays from 1 to 10kGy. We found that the reddish colour of cya-3-rut in methanol disappeared gradually in a dose-dependent manner and effectively disappeared (>97%) at 10kGy of gamma ray. Concomitantly, a new phenolic compound was generated and identified as a protocatechuic acid methyl ester by liquid chromatography, (1)H, and (13)C NMR. The formation of protocatechuic acid methyl ester increased with increasing irradiation and the amount of protocatechuic acid methyl ester formed by decomposition of cya-3-rut (20?g) at 10kGy of gamma ray was 1.95?g. In addition, the radical-scavenging activities were not affected by gamma irradiation. PMID:24629974

Lee, Seung Sik; Kim, Tae Hoon; Lee, Eun Mi; Lee, Min Hee; Lee, Ha Yeong; Chung, Byung Yeoup

2014-08-01

483

Analysis of 16 phthalic acid esters in food simulants from plastic food contact materials by LC-ESI-MS/MS.  

PubMed

An RP LC-ESI-MS/MS method for the determination of the migration of 16 primary phthalic acid esters from plastic samples has been developed using distilled water, 3% acetic acid, 10% alcohol, and olive oil as food simulants. Detection limits were 1.6-18.5 ?g/kg in distilled water, 1.4-17.3 ?g/kg in 3% acetic acid, 1.4-19.2 ?g/kg in 10% alcohol, and 31.9-390.8 ?g/kg in olive oil. The RSDs were in the range of 0.07-11.28%. The real plastic products inspection showed that only few analyzed samples were phthalates contaminated. Bis-2-ethylhexyl ester and dibutyl phthalate were the common items migrated from the plastic products into food and feeds, but the migration concentrations were far below the limits set by European Union (1.5 mg/kg for bis-2-ethylhexyl ester and 0.3 mg/kg for dibutyl phthalate). PMID:23292891

Li, Xiaojing; Xiong, Wenming; Lin, Hua; Zhuo, Liyang; Lv, Shuiyuan; Tang, Xi; Chen, Minshi; Zou, Zhexiang; Lin, Zhenyu; Qiu, Bin; Chen, Guonan

2013-02-01

484

Antioxidant activity of phenolic compounds added to a functional emulsion containing omega-3 fatty acids and plant sterol esters.  

PubMed

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 1.63g/100mL of ?-linolenic acid (ALA), 0.73g/100mL of stearidonic acid (SDA) and 0.65g/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 (200ppm) 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

Espinosa, Raquel Rainho; Inchingolo, Raffaella; Alencar, Severino Matias; Rodriguez-Estrada, Maria Teresa; Castro, Inar Alves

2015-09-01

485

Synthesis and reactions of 2-hydroxy-4-oxo-4-(2,3,5,6-tetrafluoro-4-methoxyphenyl)-but-2-enoic acid methyl ester  

Microsoft Academic Search

2-Hydroxy-4-oxo-4-(2,3,5,6-tetrafluoro-4-methoxyphenyl)-but-2-enoic acid methyl ester (1) was synthesized by the reaction of pentafluoroacetophenone with dimethyl oxalate in the presence of sodium methylate. Subsequently, reactions of compound 1 with aniline, o-phenylenediamine, and o-aminophenol were investigated. In addition, the thermal cyclization of ester 1 was studied and led to the formation of 5,6,8-trifluoro-7-methoxy-4-oxo-4H-chromene-2-carboxylic acid methyl ester (6) due to nucleophilic substitution of the

Elena V. Pimenova; Olga P. Krasnych; Elena A. Goun; D. Howard Miles

2003-01-01

486

Silicon isotope constraints on sources and utilization of silicic acid in the northern South China Sea  

NASA Astrophysics Data System (ADS)

The stable silicon isotopic composition (?30Si) of waters and diatoms has increasingly been used to investigate the biogeochemical cycling of Si in the major ocean basins. Here we present the first Si isotope data set from the northern South China Sea (NSCS), a large marginal sea system in the western North Pacific to examine sources and utilization of silicic acid (Si(OH)4). During two cruises in July-August 2009 (summer) and January 2010 (winter), samples for isotope measurements of dissolved Si(OH)4 (?30SiSi(OH)4) and of biogenic silica (?30SiBSi) in suspended particles were collected along a transect perpendicular to the coast from the inner shelf to the deep-water slope, as well as at the South East Asian Time-series Study (SEATS) station located in the NSCS basin. Surface ?30SiSi(OH)4 generally increased from values ?+2.3‰ on the inner shelf to ?+2.8‰ above the deep basin, suggesting an increasing utilization of dissolved Si(OH)4 reflecting the transition from eutrophic to oligotrophic conditions. The ?30SiBSi values were systematically lower than the corresponding ?30SiSi(OH)4 in the euphotic zone (above 100 m) on the shelf and slope. In contrast at station SEATS in the NSCS basin, ?30SiBSi signatures in both seasons were within error equal to ?30SiSi(OH)4 in the surface mixed layer (above 50 m) and ?30SiBSi in waters below were significantly higher than the corresponding ?30SiSi(OH)4. By comparing the field data with the Si isotope fractionation revealed by the Rayleigh or the steady state models, we demonstrate the existence of variable Si(OH)4 origins in different areas of the NSCS. Surface waters on the inner shelf were largely fed by nutrients from the Pearl River input. While the primary source of Si(OH)4 for the euphotic zone on the outer shelf and slope was upwelling or vertical mixing from underlying waters, the Si(OH)4 in the surface mixed layer of the NSCS basin might have originated from horizontal mixing with other highly fractionated surface waters. As a consequence, the Si isotope dynamics in the NSCS are largely controlled by variable biological fractionation of Si in waters from different sources with different initial Si isotopic compositions rather than any single source water.

Cao, Zhimian; Frank, Martin; Dai, Minhan; Grasse, Patricia; Ehlert, Claudia

2012-11-01