Science.gov

Sample records for anhydroecgonine methyl ester

  1. M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product.

    PubMed

    Garcia, Raphael Caio Tamborelli; Dati, Livia Mendonça Munhoz; Torres, Larissa Helena; da Silva, Mariana Aguilera Alencar; Udo, Mariana Sayuri Berto; Abdalla, Fernando Maurício Francis; da Costa, José Luiz; Gorjão, Renata; Afeche, Solange Castro; Yonamine, Mauricio; Niswender, Colleen M; Conn, P Jeffrey; Camarini, Rosana; Sandoval, Maria Regina Lopes; Marcourakis, Tania

    2015-01-01

    The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxic effects may involve the muscarinic cholinergic receptors (mAChRs). Our aim is to understand the interaction between AEME and mAChRs and how it can lead to neuronal death. Using a rat primary hippocampal cell culture, AEME was shown to cause a concentration-dependent increase on both total [(3)H]inositol phosphate and intracellular calcium, and to induce DNA fragmentation after 24 hours of exposure, in line with the activation of caspase-3 previously shown. Additionally, we assessed AEME activity at rat mAChR subtypes 1-5 heterologously expressed in Chinese Hamster Ovary cells. l-[N-methyl-(3)H]scopolamine competition binding showed a preference of AEME for the M2 subtype; calcium mobilization tests revealed partial agonist effects at M1 and M3 and antagonist activity at the remaining subtypes. The selective M1 and M3 antagonists and the phospholipase C inhibitor, were able to prevent AEME-induced neurotoxicity, suggesting that the toxicity is due to the partial agonist effect at M1 and M3 mAChRs, leading to DNA fragmentation and neuronal death by apoptosis. PMID:26626425

  2. M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product

    PubMed Central

    Garcia, Raphael Caio Tamborelli; Dati, Livia Mendonça Munhoz; Torres, Larissa Helena; da Silva, Mariana Aguilera Alencar; Udo, Mariana Sayuri Berto; Abdalla, Fernando Maurício Francis; da Costa, José Luiz; Gorjão, Renata; Afeche, Solange Castro; Yonamine, Mauricio; Niswender, Colleen M.; Conn, P. Jeffrey; Camarini, Rosana; Sandoval, Maria Regina Lopes; Marcourakis, Tania

    2015-01-01

    The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxic effects may involve the muscarinic cholinergic receptors (mAChRs). Our aim is to understand the interaction between AEME and mAChRs and how it can lead to neuronal death. Using a rat primary hippocampal cell culture, AEME was shown to cause a concentration-dependent increase on both total [3H]inositol phosphate and intracellular calcium, and to induce DNA fragmentation after 24 hours of exposure, in line with the activation of caspase-3 previously shown. Additionally, we assessed AEME activity at rat mAChR subtypes 1–5 heterologously expressed in Chinese Hamster Ovary cells. l-[N-methyl-3H]scopolamine competition binding showed a preference of AEME for the M2 subtype; calcium mobilization tests revealed partial agonist effects at M1 and M3 and antagonist activity at the remaining subtypes. The selective M1 and M3 antagonists and the phospholipase C inhibitor, were able to prevent AEME-induced neurotoxicity, suggesting that the toxicity is due to the partial agonist effect at M1 and M3 mAChRs, leading to DNA fragmentation and neuronal death by apoptosis. PMID:26626425

  3. Kenaf methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Additional or alternative feedstocks are one of the major areas of interest regarding biodiesel. In this paper, for the first time, the fuel properties of kenaf (Hibiscus cannabinus L.) seed oil methyl esters are comprehensively reported. This biodiesel is also relatively unique by containing small ...

  4. Kapok oil methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increased need for biodiesel feedstocks has caused various vegetable oils to be examined for this purpose. In the present work, the methyl esters of kapok (Ceiba pentandra) oil were prepared. The essential fuel properties were comprehensively determined and evaluated in comparison to specificati...

  5. Sunflower oil methyl ester as diesel fuel

    SciTech Connect

    Hassett, D.J.; Hasan, R.A.

    1982-01-01

    Methyl ester formation represents one approach to overcome the problems associated with the relatively high viscosity of sunflower oil when used as a diesel fuel replacement. Sunflower oil methyl ester is being prepared at the University of North Dakota Engieering Experiment Station. Physical and chemical properties of this material at varying levels of refinement and purity will be used to define fuel properties. Engine testing is being carried out to determine if the fouling characteristics of methyl ester are significantly less than those of sunflower oil. 1 figure, 1 table.

  6. 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...

  7. 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...

  8. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Propionic acid methyl ester (generic... Substances § 721.8660 Propionic acid methyl ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a propionic acid methyl...

  9. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Propionic acid methyl ester (generic... Substances § 721.8660 Propionic acid methyl ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a propionic acid methyl...

  10. 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...

  11. Rape oil methyl ester (RME) and used cooking oil methyl ester (UOME) as alternative fuels

    SciTech Connect

    Hohl, G.H.

    1995-12-31

    The author presents a review about the fleet tests carried out by the Austrian Armed Forces concerning the practical application of a vegetable oil, i.e Rape Oil Methyl Ester (RME) and Used Cooking Oil Methyl Ester (UOME) as alternative fuels for vehicles under military conditions, and reviews other research results carried out in Austria. As a result of over-production in Western European agriculture, the increase in crop yields has led to tremendous surpluses. Alternative agricultural products have been sought. One alternative can be seen in biological fuel production for tractors, whereby the farmer is able to produce his own fuel supply as was the case when he previously provided self-made feed for his horses. For the market introduction different activities were necessary. A considerable number of institutes and organizations including the Austrian Armed Forces have investigated, tested and developed these alternative fuels. The increasing disposal problems of used cooking oil have initiated considerations for its use. The recycling of this otherwise waste product, and its preparation for use as an alternative fuel to diesel oil, seems to be most promising.

  12. 21 CFR 172.816 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methyl glucoside-coconut oil ester. 172.816... § 172.816 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester may be safely used in food in accordance with the following conditions: (a) It is the methyl glucoside-coconut oil...

  13. 40 CFR 721.1576 - 1,3-Benzenedicarboxylic acid, bis[[4-[(ethenyloxy)methyl] cyclohexyl] methyl] ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cyclohexyl] methyl] ester. 721.1576 Section 721.1576 Protection of Environment ENVIRONMENTAL PROTECTION...] methyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3-benzenedicarboxylic acid, bis cyclohexyl] methyl] ester (PMN P-98-1162; CAS...

  14. 40 CFR 721.1576 - 1,3-Benzenedicarboxylic acid, bis[[4-[(ethenyloxy)methyl] cyclohexyl] methyl] ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... cyclohexyl] methyl] ester. 721.1576 Section 721.1576 Protection of Environment ENVIRONMENTAL PROTECTION...] methyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,3-benzenedicarboxylic acid, bis cyclohexyl] methyl] ester (PMN P-98-1162; CAS...

  15. 40 CFR 721.1578 - 1,4-Benzenedicarboxylic acid, bis[[4-[(ethenyloxy)methyl] cyclohexyl] methyl] ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cyclohexyl] methyl] ester. 721.1578 Section 721.1578 Protection of Environment ENVIRONMENTAL PROTECTION...] methyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,4-benzenedicarboxylic acid, bis cyclohexyl] methyl] ester (PMN P-98-1164; CAS...

  16. 40 CFR 721.1578 - 1,4-Benzenedicarboxylic acid, bis[[4-[(ethenyloxy)methyl] cyclohexyl] methyl] ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... cyclohexyl] methyl] ester. 721.1578 Section 721.1578 Protection of Environment ENVIRONMENTAL PROTECTION...] methyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,4-benzenedicarboxylic acid, bis cyclohexyl] methyl] ester (PMN P-98-1164; CAS...

  17. Avocado and olive oil methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, incl...

  18. 40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2... 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis - and...

  19. Stability and friction reducing properties of epoxidized oleochemical methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of oleochemicals as biobased replacements for petrochemical lubricants is an important area of study. Physical properties of the epoxidized fatty esters derived from vegetable oil are reported and compared to their olefinic counterparts. Overall the frictional behavior of epoxy methyl olea...

  20. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl glucoside-coconut oil ester. 178.3600... SANITIZERS Certain Adjuvants and Production Aids § 178.3600 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester identified in § 172.816(a) of this chapter may be safely used as a...

  1. 21 CFR 172.816 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl glucoside-coconut oil ester. 172.816 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.816 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester may be safely used in food in accordance with the following conditions: (a) It is...

  2. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Methyl glucoside-coconut oil ester. 178.3600... SANITIZERS Certain Adjuvants and Production Aids § 178.3600 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester identified in § 172.816(a) of this chapter may be safely used as a...

  3. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methyl glucoside-coconut oil ester. 178.3600 Section 178.3600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Production Aids § 178.3600 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester...

  4. 21 CFR 172.816 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Methyl glucoside-coconut oil ester. 172.816... HUMAN CONSUMPTION Multipurpose Additives § 172.816 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester may be safely used in food in accordance with the following conditions: (a) It is...

  5. 21 CFR 172.816 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Methyl glucoside-coconut oil ester. 172.816... HUMAN CONSUMPTION Multipurpose Additives § 172.816 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester may be safely used in food in accordance with the following conditions: (a) It is...

  6. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Methyl glucoside-coconut oil ester. 178.3600... SANITIZERS Certain Adjuvants and Production Aids § 178.3600 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester identified in § 172.816(a) of this chapter may be safely used as a...

  7. Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

    PubMed Central

    Bruns, Hilke; Riclea, Ramona

    2011-01-01

    Summary The volatiles released by Micromonospora aurantiaca were collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived from S-adenosyl methionine (SAM). PMID:22238549

  8. Electron driven processes in chlorodifluoroacetic acid methyl ester

    NASA Astrophysics Data System (ADS)

    Kopyra, Janina

    2014-07-01

    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.

  9. 40 CFR 721.10133 - 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hydroxyethyl ester, homopolymer. 721.10133 Section 721.10133 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10133 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester... identified as 2-propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer (PMN P-07-401; CAS No....

  10. 40 CFR 721.10133 - 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxyethyl ester, homopolymer. 721.10133 Section 721.10133 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10133 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester... identified as 2-propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer (PMN P-07-401; CAS No....

  11. 21 CFR 573.660 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methyl glucoside-coconut oil ester. 573.660 Section 573.660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ANIMALS Food Additive Listing § 573.660 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut...

  12. 21 CFR 573.660 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Methyl glucoside-coconut oil ester. 573.660 Section 573.660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ANIMALS Food Additive Listing § 573.660 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut...

  13. 21 CFR 573.660 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Methyl glucoside-coconut oil ester. 573.660 Section 573.660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ANIMALS Food Additive Listing § 573.660 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut...

  14. 21 CFR 573.660 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Methyl glucoside-coconut oil ester. 573.660 Section 573.660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ANIMALS Food Additive Listing § 573.660 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut...

  15. 21 CFR 573.660 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Methyl glucoside-coconut oil ester. 573.660 Section 573.660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ANIMALS Food Additive Listing § 573.660 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut...

  16. Ester hydroxy derivatives of methyl oleate: tribological, oxidation and low temperature properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five branched oleochemicals were prepared from commercially available methyl oleate and common organic acids and their lubricant properties were determined. These branched oleochemicals are characterized as alpha-hydroxy ester derivatives of methyl oleate. These derivatives show improved low tempe...

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

    PubMed

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

    2014-11-01

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

  18. Anaerobic biodegradation of methyl esters by Acetobacterium woodii and Eubacterium limosum.

    PubMed

    Liu, S; Suflita, J M

    1994-09-01

    The ability of Acetobacterium woodii and Eubacterium limosum to degrade methyl esters of acetate, propionate, butyrate, and isobutyrate was examined under growing and resting-cell conditions. Both bacteria hydrolyzed the esters to the corresponding carboxylates and methanol under either condition. Methanol was further oxidized to formate under growing but not resting conditions. Unlike the metabolism of phenylmethylethers, no H2 requirement was evident for ester biotransformation. The hydrolysis of methyl carboxylates is thermodynamically favorable under standard conditions and the mixotrophic metabolism of ester/CO2 allowed for bacterial growth. These results suggest that the degradation of methyl carboxylates may be a heretofore unrecognized nutritional option for acetogenic bacteria. PMID:7765371

  19. Laboratory endurance test of sunflower methyl esters for direct injected diesel engine fuel

    SciTech Connect

    Kaufman, K.; Ziejewski, M.

    1983-12-01

    A methyl ester of sunflower oil was durability tested using the test cycle recommended by the Alternate Fuels Committee of the Engine Manufacturer's Association. The results are compared to a baseline test using diesel fuel. Based on the results, the methyl ester fuel successfully completed the 200-hour durability test.

  20. Absorption and Translocation of Aminocyclopyrachlor and Aminocyclopyrachlor Methyl Ester in Canada Thistle (Cirsium arvense)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory studies were conducted using radiolabeled aminocyclopyrachlor (DPX-MAT28) and its methyl ester (DPX-KJM44) to determine the 1) importance of surfactants for herbicide absorption 2) translocation patterns of the two formulations and 3) rate that aminocyclopyrachlor methyl ester was metabol...

  1. A study on emission performance of a diesel engine fueled with five typical methyl ester biodiesels

    NASA Astrophysics Data System (ADS)

    Wu, Fujia; Wang, Jianxin; Chen, Wenmiao; Shuai, Shijin

    As an alternative and renewable fuel, biodiesel can effectively reduce diesel engine emissions, especially particulate matter and dry soot. However, the biodiesel effects on emissions may vary as the source fuel changes. In this paper, the performance of five methyl esters with different sources was studied: cottonseed methyl ester (CME), soybean methyl ester (SME), rapeseed methyl ester (RME), palm oil methyl ester (PME) and waste cooking oil methyl ester (WME). Total particulate matter (PM), dry soot (DS), non-soot fraction (NSF), nitrogen oxide (NO x), unburned hydrocarbon (HC), and carbon monoxide (CO) were investigated on a Cummins ISBe6 Euro III diesel engine and compared with a baseline diesel fuel. Results show that using different methyl esters results in large PM reductions ranging from 53% to 69%, which include the DS reduction ranging from 79% to 83%. Both oxygen content and viscosity could influence the DS emission. Higher oxygen content leads to less DS at high load while lower viscosity results in less DS at low load. NSF decreases consistently as cetane number increases except for PME. The cetane number could be responsible for the large NSF difference between different methyl esters.

  2. An Oxidation of Benzyl Methyl Ethers with NBS that Selectively Affords Either Aromatic Aldehydes or Aromatic Methyl Esters

    PubMed Central

    Mayhoub, Abdelrahman S.; Talukdar, Arindam; Cushman, Mark

    2010-01-01

    Either mono- or di-bromination of benzyl methyl ethers can be achieved by controlling the amount of NBS and the temperature. Elimination of methyl bromide from the monobrominated intermediates produces aromatic aldehydes, whereas hydrolysis of the dibrominated intermediates affords aromatic methyl esters in good yields. PMID:20373742

  3. A new sesquiterpene lactone glycoside and a new quinic acid methyl ester from Patrinia villosa.

    PubMed

    Yang, Yong-Fen; Ma, Hong-Mei; Chen, Gang; Wang, Hai-Feng; Xiang, Zheng; Feng, Qing-Mei; Hua, Hui-Ming; Pei, Yue-Hu

    2016-10-01

    A new sesquiterpene lactone glycoside (1) and a new quinic acid methyl ester (2) were isolated from Patrinia villosa, together with another two known compounds chlorogenic acid n-butyl ester (3), 3, 4-di-O-caffeoylquinic acid methyl ester (4). Their structures were established using 1D/2D-NMR spectroscopy, mass spectrometry, and comparing with spectroscopic data reported in the literature. PMID:27156969

  4. Experimental and chemical kinetic modeling study of small methyl esters oxidation: Methyl (E)-2-butenoate and methyl butanoate

    SciTech Connect

    Gail, S.; Sarathy, S.M.; Thomson, M.J.; Dievart, P.; Dagaut, P.

    2008-12-15

    This study examines the effect of unsaturation on the combustion of fatty acid methyl esters (FAME). New experimental results were obtained for the oxidation of methyl (E)-2-butenoate (MC, unsaturated C{sub 4} FAME) and methyl butanoate (MB, saturated C{sub 4} FAME) in a jet-stirred reactor (JSR) at atmospheric pressure under dilute conditions over the temperature range 850-1400 K, and two equivalence ratios ({phi}=0.375,0.75) with a residence time of 0.07 s. The results consist of concentration profiles of the reactants, stable intermediates, and final products, measured by probe sampling followed by on-line and off-line gas chromatography analyses. The oxidation of MC and MB in the JSR and under counterflow diffusion flame conditions was modeled using a new detailed chemical kinetic reaction mechanism (301 species and 1516 reactions) derived from previous schemes proposed in the literature. The laminar counterflow flame and JSR (for {phi}=1.13) experimental results used were from a previous study on the comparison of the combustion of both compounds. Sensitivity analyses and reaction path analyses, based on rates of reaction, were used to interpret the results. The data and the model show that MC has reaction pathways analogous to that of MB under the present conditions. The model of MC oxidation provides a better understanding of the effect of the ester function on combustion, and the effect of unsaturation on the combustion of fatty acid methyl ester compounds typically found in biodiesel. (author)

  5. The study of palm oil methyl ester and its corrosiveness

    NASA Astrophysics Data System (ADS)

    Sani, W. B. Wan; Samo, K. B.; Da, T. H.; Zulkifli, M. F. R.

    2012-06-01

    The present aim of this study is to determine the corrosion effect of palm oil methyl ester (POME) on aluminium alloy 5083 (AA5083). The static immersion test was carried out at 60°C for 68 days according to ASTM G-31-72. The corrosion analysis was done by using weight loss method and electrochemical test. The POME was analyzed by using Fourier Transform Infrared (FTIR) to determine its functional group. The result from weight loss method shows the decreasing in weight loss of AA5083 which signifies the ability of POME to reduce corrosion rate. The electrochemical test shows the decreasing in polarization resistance, Rp while the corrosion current densities, icorr increase. The corrosion rate reduces from 2.250mpy to 0.1946mpy. The low concentration of fatty acid C18:2 and high anti oxidant element contributes to the reduction of corrosion rate of AA5083 in POME.

  6. Green chromatography determination of fatty acid methyl esters in biodiesel.

    PubMed

    Mayo, Carlos Molina; Alayón, Andrea Brito; García Rodríguez, María Teresa; Jiménez Abizanda, Ana Isabel; Moreno, Francisco Jiménez

    2015-01-01

    This work proposes a green, simple and rapid chromatographic methodology for separation and determination of a group of 13 fatty acids methyl esters (FAMEs) by using a capillary gas chromatography with a flame ionization detector. The method was successfully applied for the determination of FAMEs in biodiesel samples from commercial and waste cooking oils, synthesized by homogeneous catalysis. Detection and quantification limits were in the μg L(-1) level. Direct injection of sample solution was compared with solid-phase extraction and solid-phase microextraction procedures, giving similar results. The lower analysis time represent considerable improvement compared with other papers. The described methodology is especially suitable for process control applications. The samples analysed showed total contents of FAMEs higher than 96.5%, which verifies the European regulations. PMID:25666201

  7. 76 FR 32332 - BASF Corp.; Filing of Food Additive Petition (Animal Use); Methyl Esters of Conjugated Linoleic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-06

    ... (Animal Use); Methyl Esters of Conjugated Linoleic Acid; Silicon Dioxide AGENCY: Food and Drug... for the safe use of methyl esters of conjugated linoleic acid (CLA) as a source of fatty acids in... part 573) to provide for the safe use of methyl esters of conjugated linoleic acid (cis-9, trans-11...

  8. 40 CFR 721.4097 - 7-Oxabicyclo[4.1.0]heptane-3-carboxylic acid, methyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., methyl ester. 721.4097 Section 721.4097 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4097 7-Oxabicyclo heptane-3-carboxylic acid, methyl ester. (a) Chemical...-oxabicyclo heptane-3-carboxylic acid, methyl ester (PMN P-98-101) is subject to reporting under this...

  9. 40 CFR 721.4097 - 7-Oxabicyclo[4.1.0]heptane-3-carboxylic acid, methyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., methyl ester. 721.4097 Section 721.4097 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4097 7-Oxabicyclo heptane-3-carboxylic acid, methyl ester. (a) Chemical...-oxabicyclo heptane-3-carboxylic acid, methyl ester (PMN P-98-101) is subject to reporting under this...

  10. Rapid enzymatic method for pectin methyl esters determination.

    PubMed

    Lękawska-Andrinopoulou, Lucyna; Vasiliou, Efstathios G; Georgakopoulos, Dimitrios G; Yialouris, Constantinos P; Georgiou, Constantinos A

    2013-01-01

    Pectin is a natural polysaccharide used in food and pharma industries. Pectin degree of methylation is an important parameter having significant influence on pectin applications. A rapid, fully automated, kinetic flow method for determination of pectin methyl esters has been developed. The method is based on a lab-made analyzer using the reverse flow-injection/stopped flow principle. Methanol is released from pectin by pectin methylesterase in the first mixing coil. Enzyme working solution is injected further downstream and it is mixed with pectin/pectin methylesterase stream in the second mixing coil. Methanol is oxidized by alcohol oxidase releasing formaldehyde and hydrogen peroxide. This reaction is coupled to horse radish peroxidase catalyzed reaction, which gives the colored product 4-N-(p-benzoquinoneimine)-antipyrine. Reaction rate is proportional to methanol concentration and it is followed using Ocean Optics USB 2000+ spectrophotometer. The analyzer is fully regulated by a lab written LabVIEW program. The detection limit was 1.47 mM with an analysis rate of 7 samples h(-1). A paired t-test with results from manual method showed that the automated method results are equivalent to the manual method at the 95% confidence interval. The developed method is rapid and sustainable and it is the first application of flow analysis in pectin analysis. PMID:24455426

  11. Rapid Enzymatic Method for Pectin Methyl Esters Determination

    PubMed Central

    Łękawska-Andrinopoulou, Lucyna; Vasiliou, Efstathios G.; Georgakopoulos, Dimitrios G.; Yialouris, Constantinos P.; Georgiou, Constantinos A.

    2013-01-01

    Pectin is a natural polysaccharide used in food and pharma industries. Pectin degree of methylation is an important parameter having significant influence on pectin applications. A rapid, fully automated, kinetic flow method for determination of pectin methyl esters has been developed. The method is based on a lab-made analyzer using the reverse flow-injection/stopped flow principle. Methanol is released from pectin by pectin methylesterase in the first mixing coil. Enzyme working solution is injected further downstream and it is mixed with pectin/pectin methylesterase stream in the second mixing coil. Methanol is oxidized by alcohol oxidase releasing formaldehyde and hydrogen peroxide. This reaction is coupled to horse radish peroxidase catalyzed reaction, which gives the colored product 4-N-(p-benzoquinoneimine)-antipyrine. Reaction rate is proportional to methanol concentration and it is followed using Ocean Optics USB 2000+ spectrophotometer. The analyzer is fully regulated by a lab written LabVIEW program. The detection limit was 1.47 mM with an analysis rate of 7 samples h−1. A paired t-test with results from manual method showed that the automated method results are equivalent to the manual method at the 95% confidence interval. The developed method is rapid and sustainable and it is the first application of flow analysis in pectin analysis. PMID:24455426

  12. Thermal Decomposition of Methyl Esters in Biodiesel Fuel: Kinetics, Mechanisms and Products

    NASA Astrophysics Data System (ADS)

    Chai, Ming

    Biodiesel continues to enjoy increasing popularity. However, recent studies on carbonyl compounds emissions from biodiesel fuel are inconclusive. Emissions of carbonyl compounds from petroleum diesel fuels were compared to emissions from pure biodiesel fuels and petroleum-biodiesel blends used in a non-road diesel generator. The concentration of total carbonyl compounds was the highest when the engine was idling. The carbonyl emissions, as well as ozone formation potential, from biodiesel fuel blends were higher than those emitted from petroleum diesel fuel. The sulfur content of diesel fuel and the source of biodiesel fuel were not found to have a significant impact on emissions of carbonyl compounds. Mechanism parameters of the thermal decomposition of biodiesel-range methyl esters were obtained from the results of thermal gravimetric analysis (TGA). The overall reaction orders are between 0.49 and 0.71 and the energies of activation are between 59.9 and 101.3 kJ/mole. Methyl esters in air have lower activation energies than those in nitrogen. Methyl linoleate has the lowest activation energy, followed by methyl oleate, and methyl stearate. The pyrolysis and oxidation of the three methyl esters were investigated using a semi-isothermal tubular flow reactor. The profiles of major products versus reaction temperature are presented. In the pyrolysis of methyl stearate, the primary reaction pathway is the decarboxylic reaction at the methyl ester functional group. Methyl oleate's products indicate more reactions on its carbon-carbon double bond. Methyl linoleate shows highest reactivity among the three methyl esters, and 87 products were detected. The oxidation of three methyl esters resulted in more products in all compound classes, and 55, 114, and 127 products were detected, respectively. The oxidation of methyl esters includes decarboxylation on ester group. The methyl ester's carbon chain could be oxidized as a hydrocarbon compound and form oxidized esters and

  13. Modeling of the oxidation of methyl esters - Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor

    SciTech Connect

    Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valerie; Battin-Leclerc, Frederique

    2010-11-15

    The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes. (author)

  14. Demethylation kinetics of aspartame and L-phenylalanine methyl ester in aqueous solution.

    PubMed

    Skwierczynski, R D; Connors, K A

    1993-08-01

    The kinetics of demethylation of aspartame and L-phenylalanine methyl ester were studied in aqueous solution at 25 degrees C over the pH range 0.27-11.5. The pseudo-first-order rate constant for aspartame was resolved into individual contributions from methyl ester hydrolysis and diketopiperazine formation. pH-rate profiles were quantitatively described by chemically reasonable kinetic schemes. Aspartame is maximally stable at pH 4 (t90 = 53 days at 25 degrees C); phenylalanine methyl ester, at pH 3. The potentiometrically measured pKa values were pKa1 3.19 and pKa2 7.87 for aspartame and pKa 7.11 for phenylalanine methyl ester. PMID:8415404

  15. 40 CFR 721.10448 - Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ester, reaction products with substituted alkylamine (generic). 721.10448 Section 721.10448 Protection... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10448 Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine (generic)....

  16. 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

    2014-07-01

    ... ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2...-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2′-(1,2-diazenediyl)bis - and 2,2... butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2),...

  17. 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

    2013-07-01

    ... ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2...-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2′-(1,2-diazenediyl)bis - and 2,2... butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2),...

  18. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to...

  19. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to...

  20. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to...

  1. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to...

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

    SciTech Connect

    Osmont, Antoine; Yahyaoui, Mohammed; Catoire, Laurent; Goekalp, Iskender; Swihart, Mark T.

    2008-10-15

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

  3. Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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 (μ) and first hyper polarizability (β) 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.

  4. Synthesis of Branched Methyl Hydroxy Stearates Including an Ester from Bio-Based Levulinic Acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the synthesis of 5 useful branched methyl alpha-hydroxy oleate esters from commercially available methyl oleate and common organic acids. Of special interest is the synthesis utilizing the natural byproduct, levulinic acid. The other common organic acids used herein were propionic acid, ...

  5. 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...

  6. Synthesis and characteristics of an aspartame analogue, L-asparaginyl L-3-phenyllactic acid methyl ester.

    PubMed

    Tao, Hu; Cui, Da-Fu; Zhang, You-Shang

    2004-06-01

    An aspartame analogue, L-asparaginyl L-3-phenyllactic acid methyl ester was synthesized with aspartic acid replaced by asparagine and peptide bond replaced by ester bond. The aspartic acid of aspartame could be replaced by asparagine as reported in the literature. In this analogue, the hydrogen of amide group could still form a hydrogen bond with the oxygen of ester bond and the ester bond was isosteric with peptide bond. However, the product was not sweet, showing that the peptide bond could not be replaced by ester bond. The peptide C-N bond behaves as a double bond that is not free to rotate and the C, O, N and H atoms are in the same plane. The replacement of peptide bond by ester bond destroyed the unique conformation of peptide bond, resulting in the loss of sweet taste. PMID:15188052

  7. A simple and sensitive fluorescent sensor for methyl parathion based on L-tyrosine methyl ester functionalized carbon dots.

    PubMed

    Hou, Juying; Dong, Jing; Zhu, Haishuang; Teng, Xue; Ai, Shiyun; Mang, Minglin

    2015-06-15

    In this paper, a simple and sensitive fluorescent sensor for methyl parathion is developed based on L-tyrosine methyl ester functionalized carbon dots (Tyr-CDs) and tyrosinase system. The carbon dots are obtained by simple hydrothermal reaction using citric acid as carbon resource and L-tyrosine methyl ester as modification reagent. The carbon dots are characterized by transmission electron microscope, high resolution transmission electron microscopy, X-ray diffraction spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The carbon dots show strong and stable photoluminescence with a quantum yield of 3.8%. Tyrosinase can catalyze the oxidation of tyrosine methyl ester on the surface of carbon dots to corresponding quinone products, which can quench the fluorescence of carbon dots. When organophosphorus pesticides (OPs) are introduced in system, they can decrease the enzyme activity, thus decrease the fluorescence quenching rate. Methyl parathion, as a model of OPs, was detected. Experimental results show that the enzyme inhibition rate is proportional to the logarithm of the methyl parathion concentration in the range 1.0×10(-10)-1.0×10(-4) M with the detection limit (S/N=3) of 4.8×10(-11) M. This determination method shows a low detection limit, wide linear range, good selectivity and high reproducibility. This sensing system has been successfully used for the analysis of cabbage, milk and fruit juice samples. PMID:25558870

  8. A Comparison Study: The New Extended Shelf Life Isopropyl Ester PMR Technology versus The Traditional Methyl Ester PMR Approach

    NASA Technical Reports Server (NTRS)

    Alston, William B.; Scheiman, Daniel A.; Sivko, Gloria S.

    2005-01-01

    Polymerization of Monomeric Reactants (PMR) monomer solutions and carbon cloth prepregs of PMR II-50 and VCAP-75 were prepared using both the traditional limited shelf life methanol based PMR approach and a novel extended shelf life isopropanol based PMR approach. The methyl ester and isopropyl ester based PMR monomer solutions and PMR prepregs were aged for up to four years at freezer and room temperatures. The aging products formed were monitored using high pressure liquid chromatography (HPLC). The composite processing flow characteristics and volatile contents of the aged prepregs were also correlated versus room temperature storage time. Composite processing cycles were developed and six ply cloth laminates were fabricated with prepregs after various extended room temperature storage times. The composites were then evaluated for glass transition temperature (Tg), thermal decomposition temperature (Td), initial flexural strength (FS) and modulus (FM), long term (1000 hours at 316 C) thermal oxidative stability (TOS), and retention of FS and FM after 1000 hours aging at 316 C. The results for each ester system were comparable. Freezer storage was found to prevent the formation of aging products for both ester systems. Room temperature storage of the novel isopropyl ester system increased PMR monomer solution and PMR prepreg shelf life by at least an order of magnitude while maintaining composite properties.

  9. Density of Jatropha curcas Seed Oil and its Methyl Esters: Measurement and Estimations

    NASA Astrophysics Data System (ADS)

    Veny, Harumi; Baroutian, Saeid; Aroua, Mohamed Kheireddine; Hasan, Masitah; Raman, Abdul Aziz; Sulaiman, Nik Meriam Nik

    2009-04-01

    Density data as a function of temperature have been measured for Jatropha curcas seed oil, as well as biodiesel jatropha methyl esters at temperatures from above their melting points to 90 ° C. The data obtained were used to validate the method proposed by Spencer and Danner using a modified Rackett equation. The experimental and estimated density values using the modified Rackett equation gave almost identical values with average absolute percent deviations less than 0.03% for the jatropha oil and 0.04% for the jatropha methyl esters. The Janarthanan empirical equation was also employed to predict jatropha biodiesel densities. This equation performed equally well with average absolute percent deviations within 0.05%. Two simple linear equations for densities of jatropha oil and its methyl esters are also proposed in this study.

  10. Oxidative stability and ignition quality of algae derived methyl esters containing varying levels of methyl eicosapentaenoate and methyl docosahexaenoate

    NASA Astrophysics Data System (ADS)

    Bucy, Harrison

    Microalgae is currently receiving strong consideration as a potential biofuel feedstock to help meet the advanced biofuels mandate of the 2007 Energy Independence and Security Act because of its theoretically high yield (gallons/acre/year) in comparison to current terrestrial feedstocks. Additionally, microalgae also do not compete with food and can be cultivated with wastewater on non-arable land. Microalgae lipids can be converted into a variety of biofuels including fatty acid methyl esters (e.g. FAME biodiesel), renewable diesel, renewable gasoline, or jet fuel. For microalgae derived FAME, the fuel properties will be directly related to the fatty acid composition of the lipids produced by the given microalgae strain. Several microalgae species under consideration for wide scale cultivation, such as Nannochloropsis, produce lipids with fatty acid compositions containing substantially higher quantities of long chainpolyunsaturated fatty acids (LC-PUFA) in comparison to terrestrial feedstocks. It is expected that increased levels of LC-PUFA will be problematic in terms of meeting all of the current ASTM specifications for biodiesel. For example, it is known that oxidative stability and cetane number decrease with increasing levels of LC-PUFA. However, these same LC-PUFA fatty acids, such as eicosapentaenoic acid (EPA: C20:5) and docosahexaenoic acid (DHA: C22:6) are known to have high nutritional value thereby making separation of these compounds economically attractive. Given the uncertainty in the future value of these LC-PUFA compounds and the economic viability of the separation process, the goal of this study was to examine the oxidative stability and ignition quality of algae-based FAME with varying levels of EPA and DHA removal. Oxidative stability tests were conducted at a temperature of 110°C and airflow of 10 L/h using a Metrohm 743 Rancimat with automatic induction period determination following the EN 14112 Method from the ASTM D6751 and EN 14214

  11. Theoretical study of cocaine and ecgonine methyl ester in gas phase and in aqueous solution

    NASA Astrophysics Data System (ADS)

    Rincón, David A.; Cordeiro, M. Natália D. S.; Mosquera, Ricardo A.; Borges, Fernanda

    2009-01-01

    The conformational preferences of cocaine and ecgonine methyl ester were determined through ab initio and density functional theory calculations. They share the same preferred orientation of the acetate group with a hydrogen bond between the amine and carbonyl groups, and s- cis conformation for the methoxyl group. The benzoyloxy group of cocaine defines a specific accessible conformational region. In solution the most stable conformers are stabilized by internal hydrogen bonds in contrast to the lesser stables, which are stabilized by solute/solvent interactions. Overall, these conformational features explain why ecgonine methyl ester is the principal metabolite of cocaine in a human environment.

  12. 40 CFR 721.4792 - 2-propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-isoalkyl esters, C13-rich. 721.4792 Section 721.4792 Protection of Environment ENVIRONMENTAL PROTECTION... esters, C13-rich. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich (PMN P-99-1189; CAS...

  13. 40 CFR 721.4792 - 2-propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-isoalkyl esters, C13-rich. 721.4792 Section 721.4792 Protection of Environment ENVIRONMENTAL PROTECTION... esters, C13-rich. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, C11-14-isoalkyl esters, C13-rich (PMN P-99-1189; CAS...

  14. Vapor movement of the synthetic auxin herbicides, aminocyclopyrachlor and its methyl ester under laboratory and enclosed chamber environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aminocyclopyrachlor (DPX MAT28) a newly discovered synthetic auxin herbicide and its methyl ester (DPX KJM44) appear to control a number of perennial broadleaf weeds. The potential volatility of this new herbicide and its methyl ester were determined under laboratory conditions and were also compar...

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

    PubMed

    Son, Hyeong-U; Lee, Sang-Han

    2013-10-01

    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

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

    PubMed Central

    SON, HYEONG-U; LEE, SANG-HAN

    2013-01-01

    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

  17. Determination of the specific radioactivity of fatty acids separated as their methyl esters by gas-liquid chromatography.

    PubMed

    Bishop, C; Glascock, R F; Newell, E M; Welch, V A

    1971-11-01

    Free or combined (3)H-labeled fatty acids are converted to their methyl-(14)C esters or, if labeled with (14)C, to their methyl-(3)H esters. For a given specific radioactivity of the methyl group, the nuclide ratio in the esters separated by GLC is a direct measure of the specific radioactivity of the fatty acids, and quantitative collection is unnecessary. Methods of methylation with minimum quantities of labeled methanol, and of deriving nuclide ratios from channel ratios in a scintillation spectrometer, are given. PMID:5124543

  18. 40 CFR 721.2078 - 1-Piperidinecarboxylic acid, 2-[(dichloro-hydroxy-carbomonocycle)hydrazono]-, methyl ester...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... generically identified as 1-piperidinecarboxylic acid, 2- -, methyl ester (PMN P-96-756) is subject to....125 (a), (b), (c), (d), (f), (g), (h), and (i) are applicable to manufacturers, importers, and... AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES...

  19. 40 CFR 721.2078 - 1-Piperidinecarboxylic acid, 2-[(dichloro-hydroxy-carbomonocycle)hydrazono]-, methyl ester...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... generically identified as 1-piperidinecarboxylic acid, 2- -, methyl ester (PMN P-96-756) is subject to....125 (a), (b), (c), (d), (f), (g), (h), and (i) are applicable to manufacturers, importers, and... AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES...

  20. 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...

  1. 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...

  2. 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...

  3. Improvement of fuel properties of cottonseed oil methyl esters with commercial additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The low temperature operability and oxidative stability of cottonseed (Gossypium hirsutum L.) oil methyl esters (CSME) were improved with addition of commercial additives. Four commercial anti-gel additives: Technol® B100 Biodiesel Cold Flow Improver, Gunk® Premium Diesel Fuel Anti-Gel, Heet® Dies...

  4. Coriander Seed Oil Methyl Esters as Biodiesel Fuel: Unique Fatty Acid Composition and Excellent Oxidative Stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid (FA) hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt %) acid. Most of the remaining FA...

  5. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  6. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  7. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  8. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  9. 21 CFR 573.640 - Methyl esters of higher fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methyl esters of higher fatty acids. 573.640 Section 573.640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  10. 40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzoic acid,...

  11. 40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Benzoic acid,...

  12. 40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Benzoic acid,...

  13. 40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Benzoic acid,...

  14. 40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzoic acid,...

  15. 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...

  16. Effects of Blending Alcohols with Poultry Fat Methyl Esters on Cold Flow Properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The low temperature operability, kinematic viscosity, and acid value of poultry fat methyl esters were improved with addition of ethanol, isopropanol, and butanol in a linear fashion with increasing alcohol content. The flash point decreased and moisture content increased upon addition of alcohols t...

  17. Prediction of preweaning ADG in beef calves from milk fatty acid methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research has shown milk yield (MWT) has an important influence on calf preweaning ADG (PRWADG), but MWT accounts for only a moderate amount of variation in PRWADG. The objective of this study was to determine if milk fatty acid methyl esters (FAME), alone and in combination with MWT, could improve a...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Methyl esters (biodiesel) from and fatty acid profile of Gliricidia sepium seed oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing the supply of biodiesel by defining and developing additional feedstocks is important to overcome the still limited amounts available of this alternative fuel. In this connection, the methyl esters of the seed oil of Gliricidia sepium were synthesized and the significant fuel-related prop...

  20. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methyl glucoside-coconut oil ester. 178.3600 Section 178.3600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and...

  1. 21 CFR 172.816 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methyl glucoside-coconut oil ester. 172.816 Section 172.816 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives...

  2. 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...

  3. 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...

  4. Low-temperature phase behavior of fatty acid methyl esters by differential scanning calorimetry (DSC)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid methyl ester (FAME) mixtures have many uses including biodiesel, lubricants, metal-working fluids, surfactants, polymers, coatings, green solvents and phase-change materials. The physical properties of a FAME mixture depends on the fatty acid concentration (FAC) profile. Some products hav...

  5. Influence of Blending Canola, Palm, Soybean, and Sunflower Oil Methyl Esters on Fuel Properties of Bioiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single, binary, ternary, and quaternary mixtures of canola (low erucic acid rapeseed), palm, soybean, and sunflower (high oleic acid) oil methyl esters (CME, PME, SME, and SFME, respectively) were prepared and important fuel properties measured, such as oil stability index (OSI), cold filter pluggin...

  6. Efficacy of Myricetin as an Antioxidant in Methyl Esters of Soybean Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antioxidant activity of myricetin, a natural flavonol found in fruits and vegetables, was determined in soybean oil methyl esters (SME) and compared with alpha-tocopherol and tert-butylhydroquinone (TBHQ) over a 90 day period employing EN 14112, acid value, and kinematic viscosity methods. Myri...

  7. The kinetics of hydrolysis of some extended N-aminoacyl-l-lysine methyl esters.

    PubMed

    Green, G D; Tomalin, G

    1976-09-01

    1. The action of two active forms of bovine trypsin (alpha and beta-trypsin) on a series of specific methyl ester substrates of general formula: N-acetyl-(glycyl)n-L-lysine methyl ester (n = 0, 1, 2) and N2-benzoyl-L-arginine ethyl ester have been investigated. With the L-lysine methyl esters the catalytic rate constant for hydrolysis (kcat) was found to be significantly lower for alpha-trypsin than for beta-trypsin, whereas with N2-benzoyl-L-arginine ethyl ester there was no significant difference for the two enzymes. 2. By measurement of the kinetic constants (kcat and Km) in the presence of a nucleophile, which competes with water in the deacylation process, it has been shown that, in common with the specific ester substrates of trypsin, the rate-determining step for the extended L-lysine methyl esters is decaylation of the enzyme. 3. It has been found that by extending the aminoacyl group of N-acetyl-L-lysine methyl ester by one glycine residue (n = 1), a greatly enhanced deacylation rate constant is observed for both alpha and beta-trypsin. The higher rate constants were maintained at the higher levels by the addition of a further glycine residue (n = 2). These results have been interpreted in terms of the 'induced fit' hypothesis the substrates binding to an enzyme subsite adjacent to the active site. 4. The beta-trypsin-catalysed hydrolysis of the L-lysine substrates was investigated over a range of temperature (15--35 degrees C). The Arrhenius law was obeyed, within experimental error, by all three substrates allowing the estimation of the thermodynamic function of activation (delta S not equal to and deltaH note equal to) for the deacylation reactions. The significantly higher values of deltaS not equal to and deltaH not equal to obtained for the two extended substrates are interpreted in terms of additional hydrogen bonding between the longer aminoacyl chains and the enzyme molecule. The results are compared with those for non-extended specific substrates

  8. Emissions from diesel engines using fatty acid methyl esters from different vegetable oils as blends and pure fuel

    NASA Astrophysics Data System (ADS)

    Schröder, O.; Munack, A.; Schaak, J.; Pabst, C.; Schmidt, L.; Bünger, J.; Krahl, J.

    2012-05-01

    Biodiesel is used as a neat fuel as well as in blends with mineral diesel fuel. Because of the limited availability of fossil resources, an increase of biogenic compounds in fuels is desired. To achieve this goal, next to rapeseed oil, other sustainably produced vegetable oils can be used as raw materials. These raw materials influence the fuel properties as well as the emissions. To investigate the environmental impact of the exhaust gas, it is necessary to determine regulated and non-regulated exhaust gas components. In detail, emissions of aldehydes and polycyclic aromatic hydrocarbons (PAH), as well as mutagenicity in the Ames test are of special interest. In this paper emission measurements on a Euro III engine OM 906 of Mercedes-Benz are presented. As fuel vegetable oil methyl esters from various sources and reference diesel fuel were used as well as blends of the vegetable oil methyl esters with diesel fuel. PAH were sampled according to VDI Guideline 3872. The sampling procedure of carbonyls was accomplished using DNPH cartridges coupled with potassium iodide cartridges. The carbon monoxide and hydrocarbon emissions of the tested methyl esters show advantages over DF. The particle mass emissions of methyl esters were likewise lower than those of DF, only linseed oil methyl ester showed higher particle mass emissions. A disadvantage is the use of biodiesel with respect to emissions of nitrogen oxides. They increased depending on the type of methyl ester by 10% to 30%. Emissions of polycyclic aromatic hydrocarbons (PAHs) and the results of mutagenicity tests correlate with those of the PM measurements, at which for palm oil methyl ester next to coconut oil methyl ester the lowest emissions were detected. From these results one can formulate a clear link between the iodine number of the ester and the emission behaviour. For blends of biodiesel and diesel fuel, emissions changed linearly with the proportion of biodiesel. However, especially in the non

  9. Efficient production of the Nylon 12 monomer ω-aminododecanoic acid methyl ester from renewable dodecanoic acid methyl ester with engineered Escherichia coli.

    PubMed

    Ladkau, Nadine; Assmann, Miriam; Schrewe, Manfred; Julsing, Mattijs K; Schmid, Andreas; Bühler, Bruno

    2016-07-01

    The expansion of microbial substrate and product scopes will be an important brick promoting future bioeconomy. In this study, an orthogonal pathway running in parallel to native metabolism and converting renewable dodecanoic acid methyl ester (DAME) via terminal alcohol and aldehyde to 12-aminododecanoic acid methyl ester (ADAME), a building block for the high-performance polymer Nylon 12, was engineered in Escherichia coli and optimized regarding substrate uptake, substrate requirements, host strain choice, flux, and product yield. Efficient DAME uptake was achieved by means of the hydrophobic outer membrane porin AlkL increasing maximum oxygenation and transamination activities 8.3 and 7.6-fold, respectively. An optimized coupling to the pyruvate node via a heterologous alanine dehydrogenase enabled efficient intracellular L-alanine supply, a prerequisite for self-sufficient whole-cell transaminase catalysis. Finally, the introduction of a respiratory chain-linked alcohol dehydrogenase enabled an increase in pathway flux, the minimization of undesired overoxidation to the respective carboxylic acid, and thus the efficient formation of ADAME as main product. The completely synthetic orthogonal pathway presented in this study sets the stage for Nylon 12 production from renewables. Its effective operation achieved via fine tuning the connectivity to native cell functionalities emphasizes the potential of this concept to expand microbial substrate and product scopes. PMID:26969251

  10. Thermally reversible gels based on acryloyl- L-proline methyl ester as drug delivery systems

    NASA Astrophysics Data System (ADS)

    Martellini, Flavia; Higa, Olga Z.; Takacs, Erzsebet; Safranj, Agneza; Yoshida, Masaru; Katakai, Ryoichi; Carenza, Mario

    1999-06-01

    Thermally reversible hydrogels were synthesized by radiation-induced copolymerization of acryloyl- L-proline methyl ester with hydrophilic or hydrophobic monomers. The swelling behaviour was found to be affected by a proper balance of the latter. In particular, the transition temperature of the different hydrogels shifted to higher or lower values depending on the presence of hydrophilic or hydrophobic moieties in the polymer chain, respectively. Acetaminophen, an analgesic and antipyretic drug, was entrapped into some hydrogels and a wide range of release rates was obtained according to the nature of the comonomers. A novel thermoresponsive hydrogel was also prepared by radiation polymerization of acryloyl- L-proline methyl ester in the presence of 4-acryloyloxy acetanilide, an acrylic derivative of acetaminophen. Again, the swelling curves showed an inverse function of temperature. It was shown that with this hydrogel bearing the drug covalently attached to the polymer backbone, the hydrolysis process was the rate-determining process of the drug release.

  11. Adsorption and wettability study of methyl ester sulphonate on precipitated asphaltene

    NASA Astrophysics Data System (ADS)

    Okafor, H. E.; Sukirman, Y.; Gholami, R.

    2016-03-01

    Asphaltene precipitation from crude oil and its subsequent aggregation forms solid, which preferentially deposit on rock surfaces causing formation damage and wettability changes leading to loss of crude oil production. To resolve this problem, asphaltene inhibitor has been injected into the formation to prevent the precipitation of asphaltene. Asphaltene inhibitors that are usually employed are generally toxic and non-biodegradable. This paper presents a new environmentally friendly asphaltene inhibitor (methyl ester sulphonate), an anionic surfactant, which has excellent sorption on formation rock surfaces. Result from adsorption study validated by Langmuir and Freundlich models indicate a favourable adsorption. At low volumes injected, methyl ester sulphonate is capable of reverting oil-wet sandstone surface to water-wet surface. Biodegradability test profile shows that for concentrations of 100-5000ppm it is biodegradable by 65-80%.

  12. Functional group analysis during ozonation of sunflower oil methyl esters by FT-IR and NMR.

    PubMed

    Soriano, Nestor U; Migo, Veronica P; Matsumura, Masatoshi

    2003-12-01

    Ozonation of neat sunflower oil (SFO) methyl esters was monitored by FT-IR and 1H and 13C NMR spectroscopy. During the early stage of ozonation, ozone absorption was essentially quantitative. This was accompanied by the formation of 1,2,4-trioxolane. IR and NMR spectra of ozonated samples showed that scission of ozonide to give aldehyde were minimal. 1H NMR analysis revealed that the amount of ozonide relative to aldehyde was more than 90% regardless of the extent of ozonation. Complete ozonation was attained after supplying around 0.20 g O3/ml methyl ester after which ozone absorption suddenly dropped to around 25%. At the latter part of ozonation, ozonide and aldehyde reacted with excess ozone to give carboxylic acid. Reaction products were identified according to Criegee mechanism. PMID:14623448

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  14. Pseudo catalytic transformation of volatile fatty acids into fatty acid methyl esters.

    PubMed

    Jung, Jong-Min; Cho, Jinwoo; Kim, Ki-Hyun; Kwon, Eilhann E

    2016-03-01

    Instead of anaerobic digestion of biodegradable wastes for producing methane, this work introduced the transformation of acidogenesis products (VFAs) into fatty acid methyl esters (FAMEs) to validate the feasible production of short-chained fatty alcohols via hydrogenation of FAMEs. In particular, among VFAs, this work mainly described the mechanistic explanations for transforming butyric acid into butyric acid methyl ester as a case study. Unlike the conventional esterification process (conversion efficiency of ∼94%), the newly introduced esterification under the presence of porous materials via the thermo-chemical process reached up to ∼99.5%. Furthermore, the newly introduced esterification via the thermo-chemical pathway in this work showed extremely high tolerance of impurities: the conversion efficiency under the presence of impurities reached up to ∼99±0.3%; thus, the inhibition behaviors attributed from the impurities used for the experimental work were negligible. PMID:26720136

  15. Synthesis of methyl esters from waste cooking oil using construction waste material as solid base catalyst.

    PubMed

    Balakrishnan, K; Olutoye, M A; Hameed, B H

    2013-01-01

    The current research investigates synthesis of methyl esters by transesterification of waste cooking oil in a heterogeneous system, using barium meliorated construction site waste marble as solid base catalyst. The pretreated catalyst was calcined at 830 °C for 4h prior to its activity test to obtained solid oxide characterized by scanning electron microscopy/energy dispersive spectroscopy, BET surface area and pore size measurement. It was found that the as prepared catalyst has large pores which contributed to its high activity in transesterification reaction. The methyl ester yield of 88% was obtained when the methanol/oil molar ratio was 9:1, reaction temperature at 65 °C, reaction time 3h and catalyst/oil mass ratio of 3.0 wt.%. The catalyst can be reused over three cycles, offer low operating conditions, reduce energy consumption and waste generation in the production of biodiesel. PMID:23186664

  16. Determination of enthalpy of formation of methyl and ethyl esters of fatty acids.

    PubMed

    Lapuerta, Magín; Rodríguez-Fernández, José; Oliva, Fermín

    2010-02-01

    Biofuels composed by fatty acid methyl esters are widely used as partly substituting fuels for diesel fossil fuels. Additionally, it is expected that the diesel biofuel norms will be extended to ethyl esters produced from bioethanol in the upcoming years. A precise knowledge of the standard enthalpy of formation is necessary for the calculation of some parameters useful for the analysis of the combustion process and emissions of a diesel engine operating with different fuels, such as the heating value, the adiabatic flame temperature or the kinetic mechanisms. However, experimental data for this property are scarce, and only available for short-chain, saturated methyl esters. In this work, four estimation methods for the calculation of the enthalpy of formation are examined and compared. Three of them are simple methods based on groups or bonds contribution, and another one is a computational method (with Gaussian 03 software). After presenting the implementation rules for each of them, conclusions are stated based on the results attained. Gaussian and Benson-Groups methods seem to be more accurate in predicting the actual values of the enthalpy of formation, both methods considering the separation between double bonds and the edge effects in the molecule. However, only the Gaussian method considers the effect of the position of the double bond in the molecule for all the unsaturated esters. PMID:19917272

  17. Effect of L-aspartyl-L-phenylalanine methyl ester on leukotriene biosynthesis in macrophage cells.

    PubMed

    Hardcastle, J E; Bruch, R J

    1997-09-01

    Macrophage cells treated with L-aspartyl-L-phenylalanine methyl ester (aspartame) produced leukotrienes and other arachidonic acid metabolites. Leukotriene C4, leukotriene B4, and 15-hydroxyeicosatetraenoic acid were the major metabolites detected. The aspartame-treated macrophage cell cultures produced three times as much arachidonic acid metabolites as did the untreated control cell cultures. Leukotriene C4 was produced in the largest amount by the aspartame-treated cells. PMID:9384524

  18. Gas chromatography-vacuum ultraviolet spectroscopy for analysis of fatty acid methyl esters.

    PubMed

    Fan, Hui; Smuts, Jonathan; Bai, Ling; Walsh, Phillip; Armstrong, Daniel W; Schug, Kevin A

    2016-03-01

    A new vacuum ultraviolet (VUV) detector for gas chromatography was recently developed and applied to fatty acid methyl ester (FAME) analysis. VUV detection features full spectral acquisition in a wavelength range of 115-240nm, where virtually all chemical species absorb. VUV absorption spectra of 37 FAMEs, including saturated, monounsaturated, and polyunsaturated types were recorded. Unsaturated FAMEs show significantly different gas phase absorption profiles than saturated ones, and these classes can be easily distinguished with the VUV detector. Another advantage includes differentiating cis/trans-isomeric FAMEs (e.g. oleic acid methyl ester and linoleic acid methyl ester isomers) and the ability to use VUV data analysis software for deconvolution of co-eluting signals. As a universal detector, VUV also provides high specificity, sensitivity, and a fast data acquisition rate, making it a powerful tool for fatty acid screening when combined with gas chromatography. The fatty acid profile of several food oil samples (olive, canola, vegetable, corn, sunflower and peanut oils) were analyzed in this study to demonstrate applicability to real world samples. PMID:26471553

  19. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the following prescribed conditions: (a)...

  20. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... amino-, di-2-propenyl ester. 721.1725 Section 721.1725 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1)...

  1. Preparation and Evaluation of Jojoba Oil Methyl Ester as Biodiesel and as Blend Components in Ultra Low Sulfur Diesel Fuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The jojoba plant (Simmondsia chinensis L.) produces seeds that contain around 50 to 60 weight percent of inedible long-chain wax esters that are suitable as a potential feedstock for biodiesel production. A Jojoba oil methyl ester (JME) was prepared in effort to evaluate an important fuel propertie...

  2. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... amino-, di-2-propenyl ester. 721.1725 Section 721.1725 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1)...

  3. 40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.304 Acetic acid, , 1-methyl hexyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as acetic acid, -, 1-methylhexyl ester (PMN...

  4. 40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.304 Acetic acid, , 1-methyl hexyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as acetic acid, -, 1-methylhexyl ester (PMN...

  5. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10136 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with...

  6. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10136 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with...

  7. 40 CFR 721.10363 - Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with 4,4′ -methylenebis...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-oxiranylmethyl ester, reaction products with 4,4â² -methylenebis (cyclohexanamine) (generic). 721.10363 Section... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10363 Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with...

  8. 40 CFR 721.10363 - Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with 4,4′ -methylenebis...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-oxiranylmethyl ester, reaction products with 4,4â² -methylenebis (cyclohexanamine) (generic). 721.10363 Section... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10363 Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with...

  9. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10136 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with...

  10. 40 CFR 721.10363 - Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with 4,4′ -methylenebis...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-oxiranylmethyl ester, reaction products with 4,4â² -methylenebis (cyclohexanamine) (generic). 721.10363 Section... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10363 Alkenoic acid, 2-methyl-, 2-oxiranylmethyl ester, reaction products with...

  11. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10136 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with...

  12. 40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10136 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with...

  13. 40 CFR 721.8450 - 2-Propenoic acid, 2-methyl-, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ester. 721.8450 Section 721.8450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.8450 2-Propenoic acid, 2-methyl-, 2- ethyl ester. (a) Chemical substance... acid, 2-methyl-, 2- ethyl ester, (PMN P-90-333) is subject to reporting under this section for...

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  15. Novel Strategy of Using Methyl Esters as Slow Release Methanol Source during Lipase Expression by mut+ Pichia pastoris X33

    PubMed Central

    Kumari, Arti; Gupta, Rani

    2014-01-01

    One of the major issues with heterologous production of proteins in Pichia pastoris X33 under AOX1 promoter is repeated methanol induction. To obviate repeated methanol induction, methyl esters were used as a slow release source of methanol in lipase expressing mut+ recombinant. Experimental design was based on the strategy that in presence of lipase, methyl esters can be hydrolysed to release their products as methanol and fatty acid. Hence, upon break down of methyl esters by lipase, first methanol will be used as a carbon source and inducer. Then P. pastoris can switch over to fatty acid as a carbon source for multiplication and biomass maintenance till further induction by methyl esters. We validated this strategy using recombinant P. pastoris expressing Lip A, Lip C from Trichosporon asahii and Lip11 from Yarrowia lipolytica. We found that the optimum lipase yield under repeated methanol induction after 120 h was 32866 U/L, 28271 U/L and 21978 U/L for Lip C, Lip A and Lip 11 respectively. In addition, we found that a single dose of methyl ester supported higher production than repeated methanol induction. Among various methyl esters tested, methyl oleate (0.5%) caused 1.2 fold higher yield for LipA and LipC and 1.4 fold for Lip11 after 120 h of induction. Sequential utilization of methanol and oleic acid by P. pastoris was observed and was supported by differential peroxisome proliferation studies by transmission electron microscopy. Our study identifies a novel strategy of using methyl esters as slow release methanol source during lipase expression. PMID:25170843

  16. Novel strategy of using methyl esters as slow release methanol source during lipase expression by mut+ Pichia pastoris X33.

    PubMed

    Kumari, Arti; Gupta, Rani

    2014-01-01

    One of the major issues with heterologous production of proteins in Pichia pastoris X33 under AOX1 promoter is repeated methanol induction. To obviate repeated methanol induction, methyl esters were used as a slow release source of methanol in lipase expressing mut+ recombinant. Experimental design was based on the strategy that in presence of lipase, methyl esters can be hydrolysed to release their products as methanol and fatty acid. Hence, upon break down of methyl esters by lipase, first methanol will be used as a carbon source and inducer. Then P. pastoris can switch over to fatty acid as a carbon source for multiplication and biomass maintenance till further induction by methyl esters. We validated this strategy using recombinant P. pastoris expressing Lip A, Lip C from Trichosporon asahii and Lip11 from Yarrowia lipolytica. We found that the optimum lipase yield under repeated methanol induction after 120 h was 32866 U/L, 28271 U/L and 21978 U/L for Lip C, Lip A and Lip 11 respectively. In addition, we found that a single dose of methyl ester supported higher production than repeated methanol induction. Among various methyl esters tested, methyl oleate (0.5%) caused 1.2 fold higher yield for LipA and LipC and 1.4 fold for Lip11 after 120 h of induction. Sequential utilization of methanol and oleic acid by P. pastoris was observed and was supported by differential peroxisome proliferation studies by transmission electron microscopy. Our study identifies a novel strategy of using methyl esters as slow release methanol source during lipase expression. PMID:25170843

  17. Lewis acid catalysed methylation of N-(9H-fluoren-9-yl)methanesulfonyl (Fms) protected lipophilic α-amino acid methyl esters.

    PubMed

    Leggio, Antonella; Alò, Danila; Belsito, Emilia Lucia; Di Gioia, Maria Luisa; Romio, Emanuela; Siciliano, Carlo; Liguori, Angelo

    2015-08-01

    This work reports an efficient Lewis acid catalysed N-methylation procedure of lipophilic α-amino acid methyl esters in solution phase. The developed methodology involves the use of the reagent system AlCl3/diazomethane as methylating agent and α-amino acid methyl esters protected on the amino function with the (9H-fluoren-9-yl)methanesulfonyl (Fms) group. The removal of Fms protecting group is achieved under the same conditions to those used for Fmoc removal. Thus the Fms group can be interchangeable with the Fmoc group in the synthesis of N-methylated peptides using standard Fmoc-based strategies. Finally, the absence of racemization during the methylation reaction and the removal of Fms group were demonstrated by synthesising a pair of diastereomeric dipeptides. PMID:25921656

  18. Benchmark Calculations for Bond Dissociation Enthalpies of Unsaturated Methyl Esters and the Bond Dissociation Enthalpies of Methyl Linolenate.

    PubMed

    Li, Xiaoyu; Xu, Xuefei; You, Xiaoqing; Truhlar, Donald G

    2016-06-16

    It is important to determine an appropriate computational method for obtaining accurate thermochemical properties of large biodiesel molecules such as methyl linolenate. In this study, we use Kohn-Sham density functional theory (DFT) and coupled cluster theory to calculate bond dissociation enthalpies (BDEs) of seven fragment molecules of methyl linolenate, in particular, propene, methyl formate, cis-3-hexene, 1,4-pentadiene, 1-pentene, butane, and methyl butanoate. The results are compared to BDEs obtained from experiments and to Oyeyemi et al.'s multireference averaged coupled pair functional (MRACPF2) calculations. We found that with extrapolation to the complete basis set (CBS) limit, the BDEs derived from coupled cluster calculations with single, double, and triple excitations (CCSDT) and from CCSDT with a perturbative treatment of connected quadruple excitations, CCSDT(2)Q/CBS, are closer to the available experimental values than those obtained by MRACPF2 for propene and methyl formate. The CCSDT/CBS calculations were chosen as the reference for validating the DFT methods. Among the density functionals, we found that M08-HX has the best performance with a mean unsigned deviation (MUD) from CCSDT/CBS of only 1.0 kcal/mol, whereas the much more expensive MRACPF2 has an MUD of 1.1 kcal/mol. We then used the most successfully validated density functionals to calculate the BDEs of methyl linolenate and compared the results with the MRACPF2 BDEs. The present study identifies several Kohn-Sham exchange-correlation functionals that should be useful for modeling ester combustion, especially the M08-HX, M06-2X, M05-2X, M08-SO, and MPWB1K global-hybrid meta functionals, the M11 and MN12-SX range-separated-hybrid meta functionals, the ωB97 range-separated hybrid gradient approximation functional, and the SOGGA11-X global-hybrid gradient approximation functional. PMID:27191950

  19. Preparation of sphingolipid fatty acid methyl esters for determination by gas-liquid chromatography.

    PubMed

    MacGee, J; Williams, M G

    1981-01-30

    Sphingolipid fatty acids are first converted to a mixture of free acids and their n-butyl esters by heating the specimen at 85 degree C in aqueous butanolic hydrogen chloride; the butyl esters are then saponified with methanolic potassium hydroxide. After acidification and extraction into hexane, the fatty acids are extracted into a very small volume of aqueous trimethyl(m-trifluorotolyl)ammonium hydroxide (TMTFTH), injection of an aliquot of the TMTFTH extract into the gas chromatograph yields the fatty acid methyl esters by pyrolytic methylation of the quaternary ammonium salts of the fatty acids. The preparation of a specimen ready for the gas--liquid chromatographic (GLC) analysis with quantitative recovery of the sphingolipid fatty acids can be accomplished in less than 2 h. By comparison, none of a number of well-accepted techniques for the release of sphingomyelin fatty acids by hydrolysis or methanolysis released the fatty acids quantitatively in less than 3 h, and all required additional manipulations before GLC analysis. PMID:7217267

  20. Methyl ester of [Maclura pomifera (Rafin.) Schneider] seed oil: biodiesel production and characterization.

    PubMed

    Saloua, Fatnassi; Saber, Chatti; Hedi, Zarrouk

    2010-05-01

    Oil extracted from seeds of Maclura pomifera fruits grown in Tunisia was investigated as an alternative feedstock for the production of biodiesel fuel. Biodiesel was prepared by transesterification of the crude oil with methanol in the presence of NaOH as catalyst. Maximum oil to ester conversion was 90%. The viscosity of the biodiesel oil (4.66 cSt) is similar to that of petroleum diesel (2.5-3.5 cSt). The density (0.889 g/cm(3)), kinematic viscosity (4.66 cSt), flash point (180 degrees Celsius), iodine number (125 degrees Celsius), neutralization number (0.4), pour point (-9 degrees Celsius), cloud point (-5 degrees Celsius), cetane number (48) are very similar to the values set forth by the ASTM and EN biodiesel standards for petroleum diesel (No. 2). The comparison shows that the methyl esters of M. pomifera oil could be possible diesel fuel replacements. PMID:20060293

  1. Synthesis of Thienamycin methyl ester from 2-deoxy-D-ribose via Kinugasa reaction.

    PubMed

    Soluch, Magdalena; Grzeszczyk, Barbara; Staszewska-Krajewska, Olga; Chmielewski, Marek; Furman, Bartłomiej

    2016-03-01

    A novel synthesis of thienamycin is described. The crucial step of the synthesis is based on Cu(I)-mediated Kinugasa cycloaddition/rearrangement cascade reaction between terminal acetylene derived from D-lactic acid and suitable, partially protected, five-membered cyclic nitrone obtained from 2-deoxy-D-ribose. The reaction was performed in the presence of tetramethylguanidine as a base to provide 5,6-trans substituted carbapenam as the main product. Thus obtained carbapenam 11 with (5R,6S) configuration at the azetidinone ring was subsequently subjected to oxidation/deprotection/oxidation reaction sequence to afford the β-keto ester 20, which was directly transformed into N,O-protected methyl ester of thienamycin. PMID:26506859

  2. Preparation of fatty acid methyl esters for gas-liquid chromatography[S

    PubMed Central

    Ichihara, Ken'ichi; Fukubayashi, Yumeto

    2010-01-01

    A convenient method using commercial aqueous concentrated HCl (conc. HCl; 35%, w/w) as an acid catalyst was developed for preparation of fatty acid methyl esters (FAMEs) from sterol esters, triacylglycerols, phospholipids, and FFAs for gas-liquid chromatography (GC). An 8% (w/v) solution of HCl in methanol/water (85:15, v/v) was prepared by diluting 9.7 ml of conc. HCl with 41.5 ml of methanol. Toluene (0.2 ml), methanol (1.5 ml), and the 8% HCl solution (0.3 ml) were added sequentially to the lipid sample. The final HCl concentration was 1.2% (w/v). This solution (2 ml) was incubated at 45°C overnight or heated at 100°C for 1–1.5 h. The amount of FFA formed in the presence of water derived from conc. HCl was estimated to be <1.4%. The yields of FAMEs were >96% for the above lipid classes and were the same as or better than those obtained by saponification/methylation or by acid-catalyzed methanolysis/methylation using commercial anhydrous HCl/methanol. The method developed here could be successfully applied to fatty acid analysis of various lipid samples, including fish oils, vegetable oils, and blood lipids by GC. PMID:19759389

  3. Sterically controlled azomethine ylide cycloaddition polymerization of phenyl-C61-butyric acid methyl ester.

    PubMed

    Stephen, Meera; Ramanitra, Hasina H; Santos Silva, Hugo; Dowland, Simon; Bégué, Didier; Genevičius, Kristijonas; Arlauskas, Kęstutis; Juška, Gytis; Morse, Graham E; Distler, Andreas; Hiorns, Roger C

    2016-05-01

    Phenyl-C61-butyric acid methyl ester (PCBM) is polymerized simply using a one-pot reaction to yield soluble, high molecular weight polymers. The sterically controlled azomethine ylide cycloaddition polymerization (SACAP) is demonstrated to be highly adaptable and yields polymers with probable Mn≈ 24 600 g mol(-1) and Mw≈ 73 800 g mol(-1). Products are metal-free and of possible benefit to organic and hybrid photovoltaics and electronics as they form thin films from solution and have raised LUMOs. The promising electronic properties of this new polymer are discussed. PMID:27066898

  4. Isolation and characterization of fatty acid methyl ester (FAME)-producing Streptomyces sp. S161 from sheep (Ovis aries) faeces.

    PubMed

    Lu, Y; Wang, J; Deng, Z; Wu, H; Deng, Q; Tan, H; Cao, L

    2013-09-01

    An actinomycete producing oil-like mixtures was isolated and characterized. The strain was isolated from sheep faeces and identified as Streptomyces sp. S161 based on 16S rRNA gene sequence analysis. The strain showed cellulase and xylanase activities. The (1) H nuclear magnetic resonance (NMR) spectra of the mixtures showed that the mixtures were composed of fatty acid methyl esters (52·5), triglycerides (13·7) and monoglycerides (9·1) (mol.%). Based on the gas chromatography-mass spectrometry (GC-MS) analysis, the fatty acid methyl esters were mainly composed of C14-C16 long-chain fatty acids. The results indicated that Streptomyces sp. S161 could produce fatty acid methyl esters (FAME) directly from starch. To our knowledge, this is the first isolated strain that can produce biodiesel (FAME) directly from starch. PMID:23692633

  5. Enzymatic Acylation of Anthocyanin Isolated from Black Rice with Methyl Aromatic Acid Ester as Donor: Stability of the Acylated Derivatives.

    PubMed

    Yan, Zheng; Li, Chunyang; Zhang, Lixia; Liu, Qin; Ou, Shiyi; Zeng, Xiaoxiong

    2016-02-10

    The enzymatic acylation of anthocyanin from black rice with aromatic acid methyl esters as acyl donors and Candida antarctica lipase B was carried out under reduced pressure. The highest conversion of 91% was obtained with benzoic acid methyl ester as acyl donor; cyanidin 3-(6″-benzoyl)-glucoside, cyanidin 3-(6″-salicyloyl)-glucoside, and cyanidin 3-(6″-cinnamoyl)-glucoside were successfully synthesized. This is the first report on the enzymatic acylation of anthocyanin from black rice with methyl aromatic esters as acyl donors and lipase as biocatalyst. Furthermore, the acylation with aromatic carboxylic acids enhanced both the thermostability and light resistivity of anthocyanin. In particular, cyanidin 3-(6″-cinnamoyl)-glucoside was the most stable among the three acylated anthocyanins synthesized. PMID:26766135

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

    PubMed Central

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

    2011-01-01

    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

  7. Theoretical and kinetic study of the hydrogen atom abstraction reactions of unsaturated C6 methyl esters with hydroxyl radical

    NASA Astrophysics Data System (ADS)

    Wang, Quan-De; Ni, Zhong-Hai

    2016-04-01

    This work reports a systematic ab initio and chemical kinetic study of the rate constants for hydrogen atom abstraction reactions by hydroxyl radical (OH) on typical isomers of unsaturated C6 methyl esters at the CBS/QB3 level of theory. The high-pressure limit rate constants at different reaction sites for all the methyl esters in the temperature range from 500 to 2000 K are calculated via transition-state theory with the Wigner method for quantum tunneling effect and fitted to the modified three parameters Arrhenius expression using least-squares regression. Further, a branching ratio analysis for each reaction site has been performed.

  8. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

  9. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

  10. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

  12. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

  13. Complementary blending of meadowfoam seed oil methyl esters with biodiesel prepared from soybean and waste cooking oils to enhance fuel properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complementary blending of meadowfoam seed oil methyl esters (MFME) with soybean and waste cooking oil methyl esters (SME and WCME) was investigated. MFME prepared from cold-pressed meadowfoam oil exhibited an exceptionally high induction period (IP) of 66.2 h whereas SME and WCME yielded conside...

  14. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i) Any... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Benzoic acid, 3,3â²-methyl-enebis...

  15. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i) Any... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Benzoic acid, 3,3â²-methyl-enebis...

  16. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i) Any... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Benzoic acid, 3,3â²-methyl-enebis...

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

    SciTech Connect

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

    2013-12-01

    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.

  18. Influence of extended storage on fuel properties of methyl esters prepared from canola, palm, soybean, and sunflower oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid methyl esters prepared from canola, palm, soybean, and sunflower oils by homogenous base-catalyzed methanolysis were stored for 12 months at three constant temperatures (-15, 22, and 40 deg C) and properties such as oxidative stability, acid value, kinematic viscosity, low temperature ope...

  19. Exhaust Emissions and Fuel Properties of Partially Hydrogenated Soybean Oil Methyl Esters Blended with Ultra Low Sulfur Diesel Fuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Important fuel properties and emissions characteristics of blends (20 vol%) of soybean oil methyl esters (SME) and partially hydrogenated SME (PHSME) in ultra low sulfur diesel fuel (ULSD) were determined and compared with neat ULSD. The following changes in physical properties were noticed for B20...

  20. 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...

  1. 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...

  2. Novel post-translational oligomerization of peptidyl dehydrodopa model compound, 1,2-dehydro-N-acetyldopa methyl ester.

    PubMed

    Abebe, Adal; Zheng, Dong; Evans, Jason; Sugumaran, Manickam

    2016-06-01

    Post-translational modification of peptidyl tyrosine to peptidyl dopa is widely observed in different marine organisms. While peptidyl dopas are oxidatively converted to dehydrodopa derivatives, nothing is known about the further fate of dehydrodopyl compounds. To fill this void, we studied the oxidation chemistry of a peptidyl dehydrodopa mimic, 1,2-dehydro-N-acetyldopa methyl ester with mushroom tyrosinase. We employed both routine biochemical studies and reversed phase liquid chromatography mass spectrometry to investigate the course of the reaction. Tyrosinase catalyzed the oxidation of 1,2-dehydro-N-acetyldopa methyl ester readily generating its typical o-quinone as the transient two-electron oxidation product. This quinone was extremely unstable and rapidly reacted with the parent compound forming benzodioxan type oligomeric products. Reaction mixture containing chemically made o-benzoquinone and 1,2-dehydro-N-acetyldopa methyl ester generated a mixed adduct of benzoquinone and 1,2-dehydro-N-acetyldopa methyl ester. Based on this finding, we propose that peptidyl dehydrodopa also exhibits a similar transformation accounting partially for the adhesive and cementing properties of dopyl proteins in nature. PMID:27010908

  3. Amonia gas: an improved reagent for chemical ionization mass spectrometry of bile acid methyl ester acetates

    SciTech Connect

    DeMark, B.R.; Klein, P.D.

    1981-01-01

    The ammonia chemical ionization mass spectra of 28 methyl ester acetate derivatives of bile acids and related compounds have been determined by gas-liquid chromatography-mass spectrometry. Advantages of ammonia ionization over the previously studied isobutane ionization include a 130 to 270% enhancement in the sensitivity of base peak monitoring, and direct determination of molecular weight from the base peak (M + NH/sub 4//sup +/) in the mass spectrum of any of the derivatives. Minor ions in the ammonia spectra also allow selective detection of 3-keto compounds and can indicate unsaturation or double bond conjugation in the molecule. The significance of these studies for the detection and quantitation of bile acids is discussed. 2 tables.

  4. Intraparticle diffusion limitations in the hydrogenation of monounsaturated edible oils and their fatty acid methyl esters

    SciTech Connect

    Jonker, G.H.; Veldsink, J.W.; Beenackers, A.A.C.M.

    1998-12-01

    Intraparticle diffusion limitation in the hydrogenation and isomerization of fatty acid methyl esters (FAMEs) and edible oils (triacylglycerol, TAG) in porous nickel catalyst was investigated both under reactive and under inert conditions. Under reactive conditions, the diffusion coefficients were determined from the best fits of the model simulations applying the intrinsic reacting kinetics of monounsaturated FAME hydrogenation to experiments under diffusion limited conditions. Due to the absence of reaction (hydrogenation of double bonds), the obtained effective H{sub z} diffusion coefficient (D{sub e}) with the HPLC technique is volume averaged and thereby determined by the larger intercrystalline pores (<30% of the total pore volume) only. Moreover, D{sub e} measured under reaction conditions reflected the influence of the micropores, resulting in a 10-fold lower value.

  5. Antifungal Activity of Narceine Methyl Ester and Narceine Isolated from Corydalis longipes Against Some Phytopathogenic Fungi

    PubMed Central

    Chowdhury, Dibyendu; Maurya, S.; Pandey, M. B.; Pandey, V. B.; Sarma, B. K.

    2005-01-01

    Narceine methyl ester and narceine are potent alkaloids which were isolated from Corydalis longipes were found effective in vitro at very low concentration, i.e., 100~500 ppm against spore germination of some test plant pathogenic fungi (Alternaria solani, A. tagetica, Cercospora abelmoschi, Curvularia maculans, Erysiphe cichoracearum, E. pisi, Fusarium udum, Helminthosporium oryzae, H. penniseti, Ustilago cynodontis). Among the test, phytopathogens the spores of F. udum, C. maculans and H. penniseti were highly sensitive at 200 ppm. However, spores of E. pisi, A. solani and A. tagetica were less sensitive at low concentration followed by other test fungi. Most of the fungi showed zero or nearly zero percent spore germination at 400 and 500 ppm. PMID:24049502

  6. (Nitrooxyacyloxy)methyl esters of aspirin as novel nitric oxide releasing aspirins.

    PubMed

    Lazzarato, Loretta; Donnola, Monica; Rolando, Barbara; Chegaev, Konstantin; Marini, Elisabetta; Cena, Clara; Di Stilo, Antonella; Fruttero, Roberta; Biondi, Stefano; Ongini, Ennio; Gasco, Alberto

    2009-08-27

    A series of (nitrooxyacyloxy)methyl esters of aspirin were synthesized and evaluated as new NO-donor aspirins. Different amounts of aspirin were released in serum from these products according to the nature of nitrooxyacyloxy moiety present. In the aromatic series, there is a rather good linear correlation between the amount of aspirin released and the potencies of the products in inhibiting platelet aggregation induced by collagen. Both the native compounds and the related nitrooxy-substituted acid metabolites were able to relax rat aorta strips precontracted with phenylephrine, in keeping with a NO-induced activation of the sGC as a mechanism that underlies the vasodilator effect. The products here described are new improved examples of NO-donor aspirins containing nitrooxy groups. They could represent an alternative to the use of aspirin in a variety of clinical applications. PMID:20560642

  7. Structural characterization and antimicrobial evaluation of atractyloside, atractyligenin, and 15-didehydroatractyligenin methyl ester.

    PubMed

    Brucoli, Federico; Borrello, Maria T; Stapleton, Paul; Parkinson, Gary N; Gibbons, Simon

    2012-06-22

    We report the first complete structure elucidation of the ent-kaurane diterpenoid glycoside atractyloside (1) by means of NMR and X-ray diffractometry techniques. Extensive one- and two-dimensional NMR experiments were employed to assign the proton and carbon signals of 1, and crystallography experiments established the configurations of all stereogenic centers. Furthermore, we present a novel semisynthetic route for the preparation of the highly cytotoxic aglycone derivative of 1, 15-didehydroatractyligenin methyl ester (3). All compounds were tested for their antibiotic activity against Enterococcus faecalis, Escherichia coli, and several strains of Staphylococcus aureus, including fluoroquinolone-resistant (SA1199B) and two epidemic MRSA (EMRSA-15 and -16) strains. Compound 3 exhibited moderate activity against all of the Staph. aureus strains with an MIC value of 128 mg/L. PMID:22594797

  8. Influence of fatty acid methyl esters from hydroxylated vegetable oils on diesel fuel lubricity.

    PubMed

    Goodrum, John W; Geller, Daniel P

    2005-05-01

    Current and future regulations on the sulfur content of diesel fuel have led to a decrease in lubricity of these fuels. This decreased lubricity poses a significant problem as it may lead to wear and damage of diesel engines, primarily fuel injection systems. Vegetable oil based diesel fuel substitutes (biodiesel) have been shown to be clean and effective and may increase overall lubricity when added to diesel fuel at nominally low levels. Previous studies on castor oil suggest that its uniquely high level of the hydroxy fatty acid ricinoleic acid may impart increased lubricity to the oil and its derivatives as compared to other vegetable oils. Likewise, the developing oilseed Lesquerella may also increase diesel lubricity through its unique hydroxy fatty acid composition. This study examines the effect of castor and Lesquerella oil esters on the lubricity of diesel fuel using the High-Frequency Reciprocating Rig (HFRR) test and compares these results to those for the commercial vegetable oil derivatives soybean and rapeseed methyl esters. PMID:15607199

  9. Comparative Studies on Performance Characteristics of CI Engine Fuelled with Neem Methyl Ester and Mahua Methyl Ester and Its Respective Blends with Diesel Fuel.

    PubMed

    Ragit, S S; Mohapatra, S K; Kundu, K

    2014-01-01

    In the present investigation, neem and mahua methyl ester were prepared by transesterification using potassium hydroxide as a catalyst and tested in 4-stroke single cylinder water cooled diesel engine. Tests were carried out at constant speed of 1500 rev/min at different brake mean effective pressures. A series of tests were conducted which worked at different brake mean effective pressures, OkPa, 1kPa, 2kPa, 3kPa, 4kPa, 5kPa, 6kPa and 6.5kPa. The performance and exhaust emission characteristics of the diesel engine were analyzed and compared with diesel fuel. Results showed that BTE of NME was comparable with diesel and it was noted that the BTE of N0100 is 63.11% higher than that of diesel at part load whereas it reduces 11.2% with diesel fuel at full load. In case of full load, NME showed decreasing trend with diesel fuel. BTE of diesel was 15.37% and 36.89% at part load and full load respectively. The observation indicated that BTE for MME 100 was slightly higher than diesel at part loads. The specific fuel consumption (SFC) was more for almost all blends at all loads, compared to diesel. At part load, the EGT of MME and its blends were showing similar trend to diesel fuel and at full load, the exhaust gas temperature of MME and blends were higher than diesel. Based on this study, NME could be a substitute for diesel fuel in diesel engine. PMID:26445759

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    A solid-phase extraction (SPE) pretreatment procedure allowing organic acids to be separated from methyl esters in fine aerosol has been developed. The procedure first separates the organic acids from fatty acid methyl esters (FAMEs) and other nonacid organic compounds by aminopropyl-based SPE cartridge and then quantifies them by gas chromatography/mass spectrometry. The procedure prevents the fatty acids and dimethyl phthalate from being overestimated, and so allows us to accurately quantify the C4-C11 dicarboxylic acids (DCAs) and the C8-C30 monocarboxylic acids (MCAs). Results for the extraction of DCAs, MCAs, and AMAs in eluate and FAMEs in effluate by SAX and NH2 SPE cartridges exhibited that the NH2 SPE cartridge gave higher extraction efficiency than the SAX cartridge. The recoveries of analytes ranged from 67.5 to 111.3 %, and the RSD ranged from 0.7 to 10.9 %. The resulting correlations between the aliphatic acids and FAMEs suggest that the 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. Through extraction and cleanup using this procedure, 17 aromatic acids in eluate were identified and quantified by gas chromatography/tandem mass spectrometry, including 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 suggested that the first three acids and 1,8-naphthalic anhydride were secondary atmospheric photochemistry products and the last two mainly primary.

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

    NASA Astrophysics Data System (ADS)

    Britton, Stephanie Lynne

    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

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

    PubMed Central

    Bobbie, Ronald J.; White, David C.

    1980-01-01

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

  13. A study of the autoxidation of some unsaturated fatty acid methyl esters using Fourier transform Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Agbenyega, J. K.; Claybourn, M.; Ellis, G.

    Near-infrared Fourier transform Raman and Fourier transform infrared spectroscopy have been used to investigate the chemical changes taking place during the curing reaction of several fatty acid methyl esters, which are used for modelling processes in the autoxidation of alkyd resin coatings. We have studied methyl oleate, methyl linoleate, and methyl linolenate in an attempt to monitor the degree of unsaturation within the fatty acid methyl esters (FAMES) during the complex autoxidation/polymerisation reaction that takes place once the paint system is coated onto a substrate and exposed to the atmosphere. The peaks around 1655 cm -1 have been assigned as follows: to the trans isomer at 1670 cm -1, the cis isomer at 1655 cm -1 and the conjugated structure at 1640 cm -1 [B. Schrader, Raman/Infrared Atlas of Organic Compounds (2nd Edn), VCH, Weinheim (1989); J. K. Abenyega, M. Claybourn and G. Ellis, in preparations]. Raman spectra for the cure of methyl linoleate after 24 h show several interesting features, suggesting the formation of a highly conjugated cyclic structure. Current theories about the mechanism for the autoxidation of methyl linoleate make no mention of this aromatic product.

  14. Preparation of fatty acid methyl esters for gas-chromatographic analysis of marine lipids: insight studies.

    PubMed

    Carvalho, Ana P; Malcata, F Xavier

    2005-06-29

    Assays for fatty acid composition in biological materials are commonly carried out by gas chromatography, after conversion of the lipid material into the corresponding methyl esters (FAME) via suitable derivatization reactions. Quantitative derivatization depends on the type of catalyst and processing conditions employed, as well as the solubility of said sample in the reaction medium. Most literature pertinent to derivatization has focused on differential comparison between alternative methods; although useful to find out the best method for a particular sample, additional studies on factors that may affect each step of FAME preparation are urged. In this work, the influence of various parameters in each step of derivatization reactions was studied, using both cod liver oil and microalgal biomass as model systems. The accuracies of said methodologies were tested via comparison with the AOCS standard method, whereas their reproducibility was assessed by analysis of variance of (replicated) data. Alkaline catalysts generated lower levels of long-chain unsaturated FAME than acidic ones. Among these, acetyl chloride and BF(3) were statistically equivalent to each other. The standard method, which involves alkaline treatment of samples before acidic methylation with BF(3), provided equivalent results when compared with acidic methylation with BF(3) alone. Polarity of the reaction medium was found to be of the utmost importance in the process: intermediate values of polarity [e.g., obtained by a 1:1 (v/v) mixture of methanol with diethyl ether or toluene] provided amounts of extracted polyunsaturated fatty acids statistically higher than those obtained via the standard method. PMID:15969474

  15. Biocatalytic potential of lipase from Staphylococcus sp. MS1 for transesterification of jatropha oil into fatty acid methyl esters.

    PubMed

    Sharma, Monika; Singh, Shelley Sardul; Maan, Pratibha; Sharma, Rohit

    2014-11-01

    An extracellular lipase producing isolate Staphylococcus sp. MS1 was optimized for lipase production and its biocatalytic potential was assessed. Medium with tributyrin (0.25 %) and without any exogenous inorganic nitrogen source was found to be optimum for lipase production from Staphylococcus sp. MS1. The optimum pH and temperature for lipase production were found to be pH 7 and 37 °C respectively, showing lipase activity of 37.91 U. It showed good lipase production at pH 6-8. The lipase was found to be stable in organic solvents like hexane and petroleum ether, showing 98 and 88 % residual activity respectively. The biotransformation using the concentrated enzyme in petroleum ether resulted in the synthesis of fatty acid methyl esters like methyl oleate, methyl palmitate and methyl stearate. Thus, the lipase under study has got the potential to bring about transesterification of oils into methyl esters which can be exploited for various biotechnological applications. PMID:25115850

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ...This regulation establishes an exemption from the requirement of a tolerance for residues of 2-propenoic acid, 2-methyl-, C12-16- alkyl esters, telomers with 1-dodecanethiol, polyethylene-polypropylene glycol ether with propylene glycol monomethacrylate (1:1), and styrene 2,2'-(1,2-diazenediyl)bis[2-methylbutanenitrile]-initiated, number average molecular weight (in AMU) 4000; when used as an......

  17. Inhibition of irritation and contact hypersensitivity by phenoxyacetic acid methyl ester in mice.

    PubMed

    Wille, J J; Kydonieus, A; Kalish, R S

    2000-01-01

    New anti-irritant treatments are required to prevent irritation and sensitization reactions to consumer medicines and dermatological drugs. We report here that phenoxyacetic acid methyl ester (PAME) is an effective agent to prevent and treat irritant and allergic contact dermatitis. Balb/c mice skin-treated with 1% PAME do not lose weight relative to vehicle-treated mice, nor is it irritating to mouse skin. Topical PAME prevents skin irritation to a wide variety of irritants including: arachidonic acid, capsaicin, sodium lauryl sulfate (SLS), disodium laureth sulfosuccinate and tetradecanoylphorbol-13-acetate. Histological studies showed that 1% PAME greatly diminished dermal neutrophilic infiltration and dermal capillary vessel dilation, and prevented epidermal hyperproliferation and hyperkeratosis that accompanies detergent (SLS)-induced skin irritation. Topical PAME inhibited ear swelling following ear challenge during the elicitation phase of contact hypersensitivity in mice sensitized with 1-chloro-2, 4-dinitrochlorobenzene (DNCB), oxazolone and the hair coloring dye rho-phenylenediamine (PPD). Finally, topical administration of 1% PAME prior to PPD or DNCB sensitization prevented the induction phase of contact hypersensitivity. These results indicate that PAME represents a potential new category of potent topical anti-inflammatory agents. PMID:10754454

  18. Polycyclic aromatic hydrocarbon removal from contaminated soils using fatty acid methyl esters.

    PubMed

    Gong, Zongqiang; Wang, Xiaoguang; Tu, Ying; Wu, Jinbao; Sun, Yifei; Li, Peng

    2010-03-01

    In this study, solubilization of PAHs from a manufactured gas plant (MGP) soil and two artificially spiked soils using fatty acid methyl esters (FAME) was investigated. PAH removals from both the MGP and the spiked soils by FAME, methanol, soybean oil, hydroxypropyl-beta-cyclodextrin, Triton X-100, and Tween 80 were compared. The effect of FAME:MGP soil ratios on PAH removals was also investigated. Results showed that the FAME mixture synthesized by our lab was more efficient than the cyclodextrin and the two surfactants used for PAH removal from the spiked soils with individual PAH concentrations of 200 and 400 mg kg(-1). However, the difference among three PAH removals by the FAME, soybean oil and methanol was not quite pronounced. The FAME synthesized and market biodiesel exhibited better performance for PAH removals (46% and 35% of total PAH) from the weathered contaminated MGP soil when compared with the other agents (0-31%). Individual PAH removals from the weathered MGP soil were much lower than those from the spiked soils. The percentages of total PAH removals from the MGP soil were 59%, 46%, and 51% for the FAME:MGP soil ratios of 1:2, 1:1, and 2:1, respectively. These results showed that the FAME could be a more attractive alternative to conventional surfactants in ex situ washing of PAH-contaminated soils. PMID:20149410

  19. Retention behaviour of unsaturated fatty acid methyl esters on porous graphitic carbon.

    PubMed

    Gaudin, Karen; Chaminade, Pierre; Baillet, Arlette

    2004-01-01

    The eluotropic strength of binary mobile phases was calculated for three homologous series of cis, trans, and cis-cis unsaturated fatty acid methyl esters (FAMEs). Binary mobile phases with chloroform, dichloromethane, or tetrahydrofuran as strong solvent and methanol or acetonitrile as weak solvent were tested. The volume fraction of strong solvent in the binary phases was between 0.3 and 0.8. Curves of eluotropic strength versus volume fraction of strong solvents showed similar trends to previously published results for saturated homologues. Correlation coefficients of the plots of eluotropic strength values for saturated versus unsaturated FAMEs were close to 1.0. Therefore these similarities validate the model of eluotropic strength previously established with saturated FAMEs as relevant for unsaturated FAMEs. The separation factors between cis and trans homologues always showed elution of the cis before the trans homologue. The difference in retention is due primarily to the geometry of the molecule. The retention is lowered more by the addition of a first carbon double bond than by the addition of a second one, independently of the mobile phase composition. PMID:15335056

  20. Adverse effects induced by ecgonine methyl ester to the zebra mussel: a comparison with the benzoylecgonine.

    PubMed

    Parolini, Marco; Binelli, Andrea

    2013-11-01

    Cocaine and its metabolites are the prevalent psychotropic substances in aquatic environment. However, to date the knowledge on their adverse effects to non-target organisms is inadequate. The aims of this study were to investigate sub-lethal effects induced by the ecgonine methyl ester (EME) to the freshwater bivalve Dreissena polymorpha and to compare its toxicity to that by benzoylecgonine (BE), the other main cocaine metabolite. EME sub-lethal effects were investigated by 14 days in-vivo exposures and a multi-biomarker approach. Slight variations in biomarker responses were found at 0.15 μg/L treatment. 0.5 μg/L EME treatment induced destabilization of lysosome membranes, an overall inactivation of defense enzymes, increases in lipid peroxidation, protein carbonylation and DNA fragmentation, but no variations in fixed genetic damage. The use of a biomarker response index (BRI) showed that at 0.5 μg/L both cocaine metabolites had the same toxicity to zebra mussels specimens. PMID:23974167

  1. Electron Affinity of Phenyl-C61-Butyric Acid Methyl Ester (PCBM)

    SciTech Connect

    Larson, Bryon W.; Whitaker, James B.; Wang, Xue B.; Popov, Alexey A.; Rumbles, Garry; Kopidakis, Nikos; Strauss, Steven H.; Boltalina, Olga V.

    2013-07-25

    The gas-phase electron affinity (EA) of phenyl-C61-butyric acid methyl ester (PCBM), one of the best-performing electron acceptors in organic photovoltaic devices, is measured by lowtemperature photoelectron spectroscopy for the first time. The obtained value of 2.63(1) eV is only ca. 0.05 eV lower than that of C60 (2.68(1) eV), compared to a 0.09 V difference in their E1/2 values measured in this work by cyclic voltammetry. Literature E(LUMO) values for PCBM that are typically estimated from cyclic voltammetry, and commonly used as a quantitative measure of acceptor properties, are dispersed over a wide range between -4.3 and -3.62 eV; the reasons for such a huge discrepancy are analyzed here, and the protocol for reliable and consistent estimations of relative fullerene-based acceptor strength in solution is proposed.

  2. Simultaneous production of fatty acid methyl esters and diglycerides by four recombinant Candida rugosa lipase's isozymes.

    PubMed

    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

    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 μL), 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

  3. Negative polarity of phenyl-C61 butyric acid methyl ester adjacent to donor macromolecule domains

    NASA Astrophysics Data System (ADS)

    Alley, Olivia J.; Wu, Meng-Yin; Johns, Gary L.; Dawidczyk, Thomas J.; Hardigree, Josué F. Martínez; Markovic, Nina; Arnold, Michael S.; Katz, Howard E.

    2015-01-01

    Interfacial fields within organic photovoltaics influence the movement of free charge carriers, including exciton dissociation and recombination. Open circuit voltage (Voc) can also be dependent on the interfacial fields, in the event that they modulate the energy gap between donor HOMO and acceptor LUMO. A rise in the vacuum level of the acceptor will increase the gap and the Voc, which can be beneficial for device efficiency. Here, we measure the interfacial potential differences at donor-acceptor junctions using Scanning Kelvin Probe Microscopy, and quantify how much of the potential difference originates from physical contact between the donor and acceptor. We see a statistically significant and pervasive negative polarity on the phenyl-C61 butyric acid methyl ester (PCBM) side of PCBM/donor junctions, which should also be present at the complex interfaces in bulk heterojunctions. This potential difference may originate from molecular dipoles, interfacial interactions with donor materials, and/or equilibrium charge transfer due to the higher work function and electron affinity of PCBM. We show that the contact between PCBM and poly(3-hexylthiophene) doubles the interfacial potential difference, a statistically significant difference. Control experiments determined that this potential difference was not due to charges trapped in the underlying substrate. The direction of the observed potential difference would lead to increased Voc, but would also pose a barrier to electrons being injected into the PCBM and make recombination more favorable. Our method may allow unique information to be obtained in new donor-acceptor junctions.

  4. New eudesmenoic acid methyl esters from the seed oil of Jatropha curcas.

    PubMed

    Yang, Yuan-Feng; Liu, Jie-Qing; Li, Zhong-Rong; Li, Yan; Qiu, Ming-Hua

    2013-09-01

    Three new eudesmenoic acid methyl esters (1-3), as well as five known compounds, including three germacranolides (4-6) and two eudesmanolides (7 and 8), were isolated from the seed oil of Jatropha curcas. The new compounds were elucidated by means of spectroscopic methods, including extensive NMR spectra. In addition, the structure of 8 was confirmed by a single-crystal X-ray diffraction analysis. Among the isolates, compounds 4-6 were the first reported from the genus Jatropha. Using MTS viability assay, the cytotoxicity of compounds 2-8 were evaluated against HL-60, SMMC-7721, A-549, MCF-7, and SW480 human tumor cell lines. Compounds 4 and 5 showed remarkable cytotoxicity against all the tested cell lines with IC50 values from 0.5 to 3.5 μM, and the new compound 3 displayed selective cytotoxic activity against A-549 cell with an IC50 value of 7.24 μM, but slight cytotoxicity against HL-60 and MCF-7 with IC50 values of 23.77 and 22.37 μM, respectively. PMID:23811432

  5. Utilization of rapeseed pellet from fatty acid methyl esters production as an energy source.

    PubMed

    Ciunel, Krzysztof; Klugmann-Radziemska, Ewa

    2014-01-01

    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

  6. 40 CFR 721.8485 - 2-Propenoic acid, 2-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. 721.8485 Section 721.8485 Protection of...-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. (a) Chemical substance and...-, (octahydro-4,7-methano- 1H- indene-5-diyl)bis(methylene) ester (PMN P-99-1075; CAS No. 43048-08-4) is...

  7. 40 CFR 721.8485 - 2-Propenoic acid, 2-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. 721.8485 Section 721.8485 Protection of...-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. (a) Chemical substance and...-, (octahydro-4,7-methano- 1H- indene-5-diyl)bis(methylene) ester (PMN P-99-1075; CAS No. 43048-08-4) is...

  8. Evaluation of the retention pattern on ionic liquid columns for gas chromatographic analyses of fatty acid methyl esters.

    PubMed

    Lin, Chen-Chen; Wasta, Ziar; Mjøs, Svein A

    2014-07-11

    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

  9. Relative kinetic measurements of rate coefficients for the gas-phase reactions of Cl atoms and OH radicals with a series of methyl alkyl esters

    NASA Astrophysics Data System (ADS)

    Schütze, Nicole; Zhong, Xiaoyin; Kirschbaum, Stefan; Bejan, Iustinian; Barnes, Ian; Benter, Thorsten

    2010-12-01

    Relative kinetic studies have been performed on the reactions of Cl atoms with a series of methyl alkyl esters in a 405-liter borosilicate glass chamber at (298 ± 3) K and one atmosphere of synthetic air using in situ FTIR spectroscopy to monitor the reactants. Rate coefficients (in units of cm 3 molecule -1 s -1) were determined for the following compounds: methyl acetate (2.48 ± 0.58) × 10 -12; methyl propanoate (1.68 ± 0.36) × 10 -11; methyl butanoate (4.77 ± 0.87) × 10 -11; methyl pentanoate (7.84 ± 1.15) × 10 -11; methyl hexanoate (1.09 ± 0.31) × 10 -10; methyl heptanoate (1.56 ± 0.37) × 10 -10; methyl cyclohexane carboxylate (3.32 ± 0.76) × 10 -10; methyl-2-methyl butanoate (9.41 ± 1.39) × 10 -11. In addition rate coefficients (in units of 10 -11 cm 3 molecule -1 s -1) have been obtained for the reactions of OH radicals with the following compounds: methyl butanoate (3.55 ± 0.71), methyl pentanoate (5.41 ± 1.08), and methyl-2-methyl butanoate (4.08 ± 0.82). Using the kinetic rate data tropospheric lifetimes for the methyl alkyl esters with respect to their reactions with OH, and Cl have been estimated for typical ambient air concentrations of these oxidants.

  10. Low Temperature Chlorine-Initiated Oxidation of Small-Chain Methyl Esters: Quantification of Chain-Terminating HO2-Elimination Channels.

    PubMed

    Muller, Giel; Scheer, Adam; Osborn, David L; Taatjes, Craig A; Meloni, Giovanni

    2016-03-17

    Cl-initiated oxidation reactions of three small-chain methyl esters, methyl propanoate (CH3CH2COOCH3; MP), methyl butanoate (CH3CH2CH2COOCH3; MB), and methyl valerate (CH3CH2CH2CH2COOCH3; MV), are studied at 1 or 8 Torr and 550 and 650 K. Products are monitored as a function of mass, time, and photoionization energy using multiplexed photoionization mass spectrometry coupled to tunable synchrotron photoionization radiation. Pulsed photolysis of molecular chlorine is the source of Cl radicals, which remove an H atom from the ester, forming a free radical. In each case, after addition of O2 to the initial radicals, chain-terminating HO2-elimination reactions are observed to be important. Branching ratios among competing HO2-elimination channels are determined via absolute photoionization spectra of the unsaturated methyl ester coproducts. At 550 K, HO2-elimination is observed to be selective, resulting in nearly exclusive production of the conjugated methyl ester coproducts, methyl propenoate, methyl-2-butenoate, and methyl-2-pentenoate, respectively. However, in MV, upon raising the temperature to 650 K, other HO2-elimination pathways are observed that yield methyl-3-pentenoate and methyl-4-pentenoate. In each methyl ester oxidation reaction, a peak is observed at a mass consistent with cyclic ether formation, indicating chain-propagating OH loss/ring formation pathways via QOOH intermediates. Evidence is observed for the participation of resonance-stabilized QOOH in the most prominent cyclic ether pathways. Stationary point energies for HO2-elimination pathways and select cyclic ether formation channels are calculated at the CBS-QB3 level of theory and assist in the assignment of reaction pathways and final products. PMID:26910881

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

    USGS Publications Warehouse

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

    1994-01-01

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

  12. Retention behaviour of polyunsaturated fatty acid methyl esters on porous graphitic carbon.

    PubMed

    Gaudin, Karen; Hanai, Toshihiko; Chaminade, Pierre; Baillet, Arlette

    2007-07-20

    Retention with porous graphitic carbon was investigated with 25 structures of fatty acid methyl esters (FAMEs) with two different mobile phases: CH(3)CN:CHCl(3) 60:40 (v/v) and CH(3)OH:CHCl(3) 60:40 (v/v) with both 0.1% triethylamine (TEA) and an equimolar amount of HCOOH. Preliminary results showed that the use of TEA/HCOOH led to the response increase of saturated FAMEs with evaporative light scattering detection. No increase was observed for unsaturated one. These modifiers may slightly reduce the retention of FAMEs but did not significantly modify the separation factor with porous graphitic carbon. Thermodynamic parameters were calculated for each structure using Van't Hoff plot measured over the temperature range from 10 to 50 degrees C, with the both mobile phase conditions. All the studied compounds were found linked by the same retention mechanism on porous graphitic carbon. Quantitative in silico analysis of the retention using a molecular mechanics calculation demonstrated a good correlation between the retention factors and the molecular interaction energy values (r>0.93). Especially the Van der Waals energy was predominant, and the contribution of electrostatic energy was negligible for the quantitative analysis of the retention. The results indicate that Van der Waals force, hydrophobic interaction, is predominant for the retention of FAMEs on this packing material. The relative retention for highly unsaturated homologues can be changed by the selection of the weak solvent CH(3)CN or CH(3)OH. Then isomers differing only in the position of the carbon double bond on the alkyl chain can be separated and their behaviour is summarised as the closer the carbon double bonds to the FAME polar head, the more the retention decreases. Finally, the more important the number of carbon double bonds in the alkyl chain is, the smaller the retention is. PMID:17543313

  13. Fatty Acid Methyl Ester Profiles for Characterization of Glomalean Fungi and Their Endomycorrhizae

    PubMed Central

    Graham, J. H.; Hodge, N. C.; Morton, J. B.

    1995-01-01

    Arbuscule-forming fungi in the order Glomales form obligate endomycorrhizal associations with plants that make them difficult to quantify, and taxonomy of the group is only beginning to be objectively understood. Fatty acid methyl ester (FAME) profiles were analyzed to assess the diversity and quantity of fatty acids in 53 isolates of 24 glomalean species. Spores and endomycorrhizal roots of sudan grass (Sorghum sudanense) and the citrus rootstock Carrizo citrange (Poncirus trifoliata x Citrus sinensis) were examined. Spores yielded reproducible FAME profiles from replicate spore collections extracted from soil pot cultures despite being grown in association with a host plant and with contaminating microorganisms present. Unweighted pair group analysis revealed relatively tight clusters of groups at the intraspecific, specific, and generic levels; however, lipid profiles at the family level were convergent. Thus, FAME profile comparisons provided a robust measure of similarity below the family level. FAME profiles in sudan grass roots containing vesicles and/or spores of Glomus intraradices were more similar to spore profiles than to profiles from nonmycorrhizal roots. The FAME profiles for Gigaspora species, which do not form vesicles or spores in roots, were less distinct from nonmycorrhizal roots. G. intraradices and G. rosea produced fatty acids in roots that were distinguishable from each other as well as from the host root. Production in citrus roots of the fatty acid 16:1(inf(omega)5) cis by two Glomus species was correlated with the development of mycorrhizal colonization as measured by clearing and staining procedures and by estimates of total incidence and vesicle intensity. FAME analysis of roots not only provided a measure of colonization development but also served as an index of carbon allocated to intraradical fungal growth and lipid storage. PMID:16534923

  14. Labdanolic acid methyl ester (LAME) exerts anti-inflammatory effects through inhibition of TAK-1 activation.

    PubMed

    Cuadrado, Irene; Cidre, Florencia; Herranz, Sandra; Estevez-Braun, Ana; de las Heras, Beatriz; Hortelano, Sonsoles

    2012-01-01

    Labdane derivatives obtained from the diterpenoid labdanediol suppressed NO and PGE(2) production in LPS-stimulated RAW 264.7 macrophages. However, mechanisms involved in these inhibitory effects are not elucidated. In this study, we investigated the signaling pathways involved in the anti-inflammatory effects of labdanolic acid methyl ester (LAME) in peritoneal macrophages and examined its therapeutic effect in a mouse endotoxic shock model. LAME reduced the production of NO and PGE(2) in LPS-activated macrophages. This effect involved the inhibition of NOS-2 and COX-2 gene expression, acting at the transcription level. Examination of the effects of the diterpene on NF-κB signaling showed that LAME inhibits the phosphorylation of IκBα and IκBβ, preventing their degradation and the nuclear translocation of the NF-κB p65 subunit. Moreover, inhibition of MAPK signaling was also observed. A further experiment revealed that LAME inhibited the phosphorylation of transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1), an upstream signaling molecule required for IKK and mitogen-activated protein kinases (MAPKs) activation. Inflammatory cytokines such as IL-6, TNF-α and IP-10 were downregulated in the presence of this compound after stimulation with LPS. Additionally, LAME also improved survival in a mouse model of endotoxemia and reduced the circulatory levels of cytokines (IL-6, TNF-α). In conclusion, these results indicate that labdane diterpene LAME significantly attenuates the pro-inflammatory response induced by LPS both in vivo and in vitro. PMID:22036724

  15. Structural characterization of saturated branched chain fatty acid methyl esters by collisional dissociation of molecular ions generated by electron ionization.

    PubMed

    Ran-Ressler, Rinat R; Lawrence, Peter; Brenna, J Thomas

    2012-01-01

    Saturated branched chain fatty acids (BCFA) are present as complex mixtures in numerous biological samples. The traditional method for structure elucidation, electron ionization (EI) mass spectrometry, sometimes does not unambiguously enable assignment of branching in isomeric BCFA. Zirrolli and Murphy (Zirrolli , J. A. , and R. A. Murphy. 1993. Low-energy tandem mass spectrometry of the molecular ion derived from fatty acid methyl esters: a novel method for analysis of branched-chain fatty acids. J. Am. Soc. Mass Spectrom. 4: 223-229.) showed that the molecular ions of four BCFA methyl ester (BCFAME) yield highly characteristic fragments upon collisional dissociation using a triple quadrupole instrument. Here, we confirm and extend these results by analysis using a tabletop 3-D ion trap for activated molecular ion EI-MS/MS to 30 BCFAME. iso-BCFAME produces a prominent ion (30-100% of base peak) for [M-43] (M-C₃H₇), corresponding to the terminal isopropyl moiety in the original iso-BCFAME. Anteiso-FAME yield prominent ions (20-100% of base peak) corresponding to losses on both side of the methyl branch, [M-29] and [M-57], and tend to produce more prominent m/z 115 peaks corresponding to a cyclization product around the ester. Dimethyl and tetramethyl FAME, with branches separated by at least one methylene group, yield fragment on both sides of the sites of methyl branches that are more than 6 C away from the carboxyl carbon. EI-MS/MS yields uniquely specific ions that enable highly confident structural identification and quantification of BCFAME. PMID:22021637

  16. 40 CFR 721.10526 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  17. 40 CFR 721.10526 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  18. Effects of 2,3-Dehydrosilybin and Its Galloyl Ester and Methyl Ether Derivatives on Human Umbilical Vein Endothelial Cells.

    PubMed

    Karas, Daniel; Gažák, Radek; Valentová, Kateřina; Chambers, Christopher S; Pivodová, Veronika; Biedermann, David; Křenková, Alena; Oborná, Ivana; Kuzma, Marek; Cvačka, Josef; Ulrichová, Jitka; Křen, Vladimír

    2016-04-22

    The effects in vitro of 2,3-dehydrosilybin and several galloyl esters and methyl ethers on the viability, proliferation, and migration of human umbilical vein endothelial cells (HUVECs) were evaluated. The monogalloyl esters were synthesized by a chemoselective esterification method or by Steglich esterification of suitably protected 2,3-dehydrosilybin (1) with protected gallic acid. 2,3-Dehydrosilybin (1) displayed more potent cytotoxic, antiproliferative, and antimigratory activities (IC50 12.0, 5.4, and 12.2 μM, respectively) than silybin. The methylated derivatives were less active, with the least potent being 3,7-di-O-methyl-2,3-dehydrosilybin (6). On the other hand, galloylation at C-7 OH and C-23 OH markedly increased the cytotoxicity and the effects on the proliferation and migration of HUVECs. The most active derivative was 7-O-galloyl-2,3-dehydrosilybin (13; IC50 value of 3.4, 1.6, and 4.7 μM in the cytotoxicity, inhibition of proliferation, and antimigratory assays, respectively). Overall, this preliminary structure-activity relationship study demonstrated the importance of a 2,3-double bond, a C-7 OH group, and a galloyl moiety in enhancing the activity of flavonolignans toward HUVECs. PMID:27015547

  19. 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)

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

    1971-01-01

    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.

  20. Construction of combustion models for rapeseed methyl ester bio-diesel fuel for internal combustion engine applications.

    PubMed

    Golovitchev, Valeri I; Yang, Junfeng

    2009-01-01

    Bio-diesel fuels are non-petroleum-based diesel fuels consisting of long chain alkyl esters produced by the transesterification of vegetable oils, that are intended for use (neat or blended with conventional fuels) in unmodified diesel engines. There have been few reports of studies proposing theoretical models for bio-diesel combustion simulations. In this study, we developed combustion models based on ones developed previously. We compiled the liquid fuel properties, and the existing detailed mechanism of methyl butanoate ester (MB, C(5)H(10)O(2)) oxidation was supplemented by sub-mechanisms for two proposed fuel constituent components, C(7)H(16) and C(7)H(8)O (and then, by mp2d, C(4)H(6)O(2) and propyne, C(3)H(4)) to represent the combustion model for rapeseed methyl ester described by the chemical formula, C(19)H(34)O(2) (or C(19)H(36)O(2)). The main fuel vapor thermal properties were taken as those of methyl palmitate C(19)H(36)O(2) in the NASA polynomial form of the Burcat database. The special global reaction was introduced to "crack" the main fuel into its constituent components. This general reaction included 309 species and 1472 reactions, including soot and NO(x) formation processes. The detailed combustion mechanism was validated using shock-tube ignition-delay data under diesel engine conditions. For constant volume and diesel engine (Volvo D12C) combustion modeling, this mechanism could be reduced to 88 species participating in 363 reactions. PMID:19409477

  1. Unequivocal NMR assignments: O-methoxy-methyl esters derivatives of acid chromanones from Calophyllum brasiliense CAMB. (Guanandi).

    PubMed

    Caneppele, D; Vieira, P C; Dall'Oglio, E L; da Silva, L E; Sousa, P T

    2008-01-01

    The present work describes the fractionation of the crude hexane extract (EBHEX) from Calophyllum brasiliense (Clusiaceae) stem bark. Derivatization of DCM(2-9) fraction with diazomethane afforded the chromanones inophylloidic acid, isobrasiliensic acid, as well as, a mixture containing isobrasiliensic and brasiliensic acids, in the form of their more stable O-methoxy-methyl esters derivatives 1, 2, and 3, respectively. The isolation of 1 from C. brasiliense is described for the first time herein. The use of two-dimensional NMR methods ((1)H-COSY, HMQC, and HMBC) allowed the precise determination of (13)C and (1)H chemical shifts of compounds 1, 2, and 3. PMID:18626818

  2. High-performance liquid chromatographic determination of L-aspartyl-L-phenylalanine methyl ester in various food products and formulations.

    PubMed

    Fox, L; Anthony, G D; Lau, E P

    1976-09-01

    A simple, rapid, and specific high-performance liquid chromatographic (HPLC) procedure is described for the analysis of the chemical sweetener L-aspartyl-L-phenylalanine methyl ester (aspartame). Using a strong cation exchange column and pressures less than 1000 psig, an analysis can be performed in less than 15 min. The technique has been applied to a wide range of food products and formulations. No interferences were found in the samples studied. Recoveries are quantitative, and the coefficients of variation for replicate analyses are less than or equal to 2.5%. PMID:965327

  3. Labdanolic acid methyl ester (LAME) exerts anti-inflammatory effects through inhibition of TAK-1 activation

    SciTech Connect

    Cuadrado, Irene; Estevez-Braun, Ana; Heras, Beatriz de las

    2012-01-01

    Labdane derivatives obtained from the diterpenoid labdanediol suppressed NO and PGE{sub 2} production in LPS-stimulated RAW 264.7 macrophages. However, mechanisms involved in these inhibitory effects are not elucidated. In this study, we investigated the signaling pathways involved in the anti-inflammatory effects of labdanolic acid methyl ester (LAME) in peritoneal macrophages and examined its therapeutic effect in a mouse endotoxic shock model. LAME reduced the production of NO and PGE{sub 2} in LPS-activated macrophages. This effect involved the inhibition of NOS-2 and COX-2 gene expression, acting at the transcription level. Examination of the effects of the diterpene on NF-κB signaling showed that LAME inhibits the phosphorylation of IκBα and IκBβ, preventing their degradation and the nuclear translocation of the NF-κB p65 subunit. Moreover, inhibition of MAPK signaling was also observed. A further experiment revealed that LAME inhibited the phosphorylation of transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1), an upstream signaling molecule required for IKK and mitogen-activated protein kinases (MAPKs) activation. Inflammatory cytokines such as IL-6, TNF-α and IP-10 were downregulated in the presence of this compound after stimulation with LPS. Additionally, LAME also improved survival in a mouse model of endotoxemia and reduced the circulatory levels of cytokines (IL-6, TNF-α). In conclusion, these results indicate that labdane diterpene LAME significantly attenuates the pro-inflammatory response induced by LPS both in vivo and in vitro. Highlights: ► LAME reduced the production of NO and PGE{sub 2} in LPS-activated macrophages. ► IL-6, TNF-α and IP-10 were also inhibited by LAME. ► Inhibition of TAK-1 activation is the mechanism involved in this process. ► LAME improved survival in a mouse model of endotoxemia. ► LAME reduced the circulatory levels of cytokines (IL-6, TNF-α).

  4. Systematic evaluation of methyl ester bioisosteres in the context of developing alkenyldiarylmethanes (ADAMs) as non-nucleoside reverse transcriptase inhibitors (NNRTIs) for anti-HIV-1 chemotherapy.

    PubMed

    Hoshi, Ayako; Sakamoto, Takeshi; Takayama, Jun; Xuan, Meiyan; Okazaki, Mari; Hartman, Tracy L; Buckheit, Robert W; Pannecouque, Christophe; Cushman, Mark

    2016-07-01

    The alkenyldiarylmethanes (ADAMs) are a class of non-nucleoside reverse transcriptase inhibitors (NNRTIs) targeting HIV-1. Four chemically and metabolically stabilized ADAMs incorporating N-methoxyimidoyl halide replacements of the methyl esters of the lead compound were previously reported. In this study, twenty-five new ADAMs were synthesized in order to investigate the biological consequences of installing nine different methyl ester bioisosteres at three different locations. Attempts to define a universal rank order of methyl ester bioisosteres and discover the 'best' one in terms of inhibitory activity versus HIV-1 reverse transcriptase (RT) led to the realization that the potencies are critically dependent on the surrounding structure at each location, and therefore the definition of universal rank order is impossible. This investigation produced several new non-nucleoside reverse transcriptase inhibitors in which all three of the three methyl esters of the lead compound were replaced by methyl ester bioisosteres, resulting in compounds that are more potent as HIV-1 RT inhibitors and antiviral agents than the lead compound itself and are expected to also be more metabolically stable than the lead compound. PMID:27234889

  5. Solvent free hydroxylation of the methyl esters of Blighia unijugata seed oil in the presence of cetyltrimethylammonium permanganate

    PubMed Central

    2011-01-01

    Extraction of oil from the seed of Blighia unijugata gave a yield of 50.82 ± 1.20% using hexane in a soxhlet extractor. The iodine and saponification values were 67.60 ± 0.80 g iodine/100 g and 239.20 ± 1.00 mg KOH/g respectively with C18:1 being the dominant fatty acid. Unsaturated methyl esters of Blighia unijugata which had been previously subjected to urea adduct complexation was used to synthesize methyl 9, 10-dihydroxyoctadecanoate via hydroxylation in the presence of cetyltrimethylammonium permanganate (CTAP). The reaction was monitored and confirmed using FTIR and GC-MS. This study has revealed that oxidation reaction of mono unsaturated bonds using CTAP could be achieved under solvent free condition. PMID:22145711

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

    PubMed

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

    2005-01-01

    This paper describes the synthesis and gas chromatography/electron ionization mass spectrometric (GC/EI-MS) analysis of methyl esters of N,N-dialkylaminoethane-2-sulfonic acids (DAESAs). These sulfonic acids are important environmental signatures of nerve agent VX and its toxic analogues, hence GC/EI-MS analysis of their methyl esters is of paramount importance for verification of the Chemical Weapons Convention. DAESAs were prepared by condensation of 2-bromoethane sulfonic acid with dialkylamines, and by condensation of dialkylaminoethyl chloride with sodium bisulfite. GC/EI-MS analysis of methyl esters of DAESAs yielded mass spectra; based on these spectra, generalized fragmentation routes are proposed that rationalize most of the characteristic ions. PMID:16196000

  7. Purification and characterization of solvent tolerant lipase from Bacillus sp. for methyl ester production from algal oil.

    PubMed

    Sivaramakrishnan, Ramachandran; Incharoensakdi, Aran

    2016-05-01

    Lipase from Bacillus sp. isolated from the oil contaminated soil was purified by ammonium sulphate precipitation and ion-exchange chromatography with a 5.1-fold purification and 10.5% yield. SDS-PAGE analysis of the enzyme revealed the molecular mass of 24 kDa. The optimum pH and temperature for lipase activity were 6.5 and 37°C, respectively. The isolated lipase was stimulated by pretreatment with methanol and ethanol as well as by divalent metal ions Ca(2+), Mg(2+) and Mn(2+). The enzyme showed high activity towards oleic rich oils. The enzyme immobilized on celite could retain 90% lipase activity after eight cycles. Transesterification of Botryococcus sp. oil using the immobilized enzyme for 40 h resulted in 80% yield of fatty acid methyl esters which had good properties for use as biodiesel. Overall results suggested that the solvent tolerant Bacillus lipase can be a potential biocatalyst for methyl ester production. PMID:26467697

  8. A database of chromatographic properties and mass spectra of fatty acid methyl esters from omega-3 products.

    PubMed

    Wasta, Ziar; Mjøs, Svein A

    2013-07-19

    Fatty acids in products claimed to contain oils with the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were analyzed as fatty acid methyl esters by gas chromatography-mass spectrometry using electron impact ionization. To cover the variation in products on the market, the 20 products that were studied in detail were selected from a larger sample set by statistical methodology. The samples were analyzed on two different stationary phases (polyethylene glycol and cyanopropyl) and the fatty acid methyl esters were identified by methodology that combines the mass spectra and retention indices into a single score value. More that 100 fatty acids had a chromatographic area above 0.1% of the total, in at least one product. Retention indices are reported as equivalent chain lengths, and overlap patterns on the two columns are discussed. Both columns were found suitable for analysis of major and nutritionally important fatty acids, but the large number of minor compounds that may act as interferents will be problematic if low limits of quantification are required in analyses of similar sample types. A database of mass spectral libraries and equivalent chain lengths of the detected compounds has been compiled and is available online. PMID:23773584

  9. Quantification of trace fatty acid methyl esters in diesel fuel by using multidimensional gas chromatography with electron and chemical ionization mass spectrometry.

    PubMed

    Webster, R L; Rawson, P M; Evans, D J; Marriott, P J

    2016-07-01

    Measurement of contamination of marine and naval diesel fuels (arising from product mixing or adulteration) with biodiesel or fatty acid methyl esters can be problematic, especially at very low levels. A suitable solution for this task for trace amounts of individual fatty acid methyl esters with resolution and quantification can be achieved by using a multidimensional gas chromatographic approach with electron and chemical ionization mass spectrometric detection. A unique column set comprising a 100 m methyl-siloxane nonpolar first dimension column and high-temperature ionic liquid column in the second dimension enabled identification of individual fatty acid methyl esters at below the lowest concentrations required to be reported in a diesel fuel matrix. Detection limits for individual fatty acid methyl esters compounds ranged from 0.5 to 5.0 mg/L, with excellent linearity up to 5000 mg/L and repeatability of the method from 1.3 to 3.2%. The method was applied to the analysis of diesel fuel samples with suspected biodiesel contamination. Contamination at 568 mg/L was calculated for an unknown sample and interpretation of the results permitted the determination of a likely source of the contamination. PMID:27159197

  10. A comprehensive evaluation of the cetane numbers of fatty acid methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cetane number (CN) is a prime indicator of the quality of diesel fuels, including those derived from renewable resources such as biodiesel. While many effects of compound structure are known or have been postulated, experimental data have not always been available for the various ester component...

  11. Fuel properties of highly polyunsaturated fatty acid methyl esters: Prediction of fuel properties of algal biodiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats, can be derived from other triacylglycerol-containing feedstocks. Especially algae are being considered for this purpose due to their claimed high production potential. However, there are no comprehensive reports regarding...

  12. Synthesis of fatty acid methyl ester from crude jatropha (Jatropha curcas Linnaeus) oil using aluminium oxide modified Mg-Zn heterogeneous catalyst.

    PubMed

    Olutoye, M A; Hameed, B H

    2011-06-01

    The synthesis of fatty acid methyl esters (FAME) as a substitute to petroleum diesel was investigated in this study from crude jatropha oil (CJO), a non-edible, low-cost alternative feedstock, using aluminium modified heterogeneous basic oxide (Mg-Zn) catalyst. The transesterification reaction with methanol to methyl esters yielded 94% in 6h with methanol-oil ratio of 11:1, catalyst loading of 8.68 wt.% at 182°C and the properties of CJO fuel produced were determine and found to be comparable to the standards according to ASTM. In the range of experimental parameters investigated, it showed that the catalyst is selective to production of methyl esters from oil with high free fatty acid (FFA) and water content of 7.23% and 3.28%, respectively in a single stage process. Thus, jatropha oil is a promising feedstock for methyl ester production and large scale cultivation will help to reduce the product cost. PMID:21486692

  13. 40 CFR 721.8450 - 2-Propenoic acid, 2-methyl-, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, 2- ethyl ester. 721.8450 Section 721.8450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses...

  14. 40 CFR 721.8450 - 2-Propenoic acid, 2-methyl-, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, 2- ethyl ester. 721.8450 Section 721.8450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses...

  15. 40 CFR 721.8450 - 2-Propenoic acid, 2-methyl-, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 2-Propenoic acid, 2-methyl-, 2- ethyl ester. 721.8450 Section 721.8450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses...

  16. 40 CFR 721.8450 - 2-Propenoic acid, 2-methyl-, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, 2- ethyl ester. 721.8450 Section 721.8450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses...

  17. 21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol...

  18. 21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol...

  19. Enzymatic synthesis of theanine from glutamic acid γ-methyl ester and ethylamine by immobilized Escherichia coli cells with γ-glutamyltranspeptidase activity.

    PubMed

    Zhang, Fei; Zheng, Qing-Zhong; Jiao, Qing-Cai; Liu, Jun-Zhong; Zhao, Gen-Hai

    2010-11-01

    Theanine (γ-glutamylethylamide) is the main amino acid component in green tea. The demand for theanine in the food and pharmaceutical industries continues to increase because of its special flavour and multiple physiological effects. In this research, an improved method for enzymatic theanine synthesis is reported. An economical substrate, glutamic acid γ-methyl ester, was used in the synthesis catalyzed by immobilized Escherichia coli cells with γ-glutamyltranspeptidase (GGT) activity. The results show that GGT activity with glutamic acid γ-methyl ester as substrate was about 1.2-folds higher than that with glutamine as substrate. Reaction conditions were optimized by using 300 mmol/l glutamic acid γ-methyl ester, 3,000 mmol/l ethylamine, and 0.1 g/ml of immobilized GGT cells at pH 10 and 50°C. Under these conditions, the immobilized cells were continuously used ten times, yielding an average glutamic acid γ-methyl ester to theanine conversion rate of 69.3%. Bead activity did not change significantly the first six times they were used, and the average conversion rate during the first six instances was 87.2%. The immobilized cells exhibited favourable operational stability. PMID:20238131

  20. Configurational and conformational analysis of chiral molecules using IR and VCD spectroscopies: spiropentylcarboxylic acid methyl ester and spiropentyl acetate.

    PubMed

    Devlin, F J; Stephens, P J; Osterle, C; Wiberg, K B; Cheeseman, J R; Frisch, M J

    2002-11-15

    The chiral monosubstituted derivatives of spiropentane, spiropentylcarboxylic acid methyl ester, 1, and spiropentyl acetate, 2, have been synthesized in optically active form. Configurational and conformational analysis of 1 and 2 has been carried out using infrared (IR) and vibrational circular dichroism (VCD) spectroscopies. Analysis of the experimental IR and VCD spectra has been carried out using ab initio density functional theory (DFT). For both 1 and 2, DFT predicts two populated conformations. Comparison to experiment of the conformationally averaged IR and VCD spectra of 1 and 2, predicted using DFT, provides unequivocal evidence of the predicted conformations and yields the absolute configurations R(-)/S(+) for 1 and R(+)/S(-) for 2. These absolute configurations are consistent with the R(-)/S(+) absolute configuration of spiropentylcarboxylic acid, assigned previously via X-ray crystallography of its alpha-phenylethylammonium salt. PMID:12423137

  1. Environmental effect of antioxidant additives on exhaust emission reduction in compression ignition engine fuelled with Annona methyl ester.

    PubMed

    Senthil, R; Silambarasan, R

    2015-01-01

    The aim of the present study is to analyse the effect of antioxidant l-ascorbic acid on engine performance and emissions of a diesel engine fuelled with methyl ester of Annona oil (MEAO). The antioxidant is mixed in various concentrations (100-400 mg) with MEAO. Result shows that the antioxidant additive mixture (MEAO+LA200) is effective in control of nitrogen oxides (NOx) and hydrocarbon (HC) emission of MEAO-fuelled engine without doing any engine modification. In this study by using MEAO, the NOx emission is reduced by about 23.38% at full load while compared with neat diesel fuel. Likewise there is a reduction in carbon monoxide, smoke, and HC by about 48%, 28.57% and 29.71% at full load condition compared with neat diesel fuel. PMID:25704338

  2. Benzoyl-L-arginine methyl ester (BAME)-esterase activity in human plasma during the gravidic-puerperal cycle.

    PubMed

    Salles Meirelles, R

    1977-01-01

    Benzoyl-L-arginine methyl ester (BAME)-esterase activity of plasma was measured in women going through the gravidic-puerperal cycle and compared with plasma of non-pregnant women. Plasma from women in the 36th to 40th week of pregnancy hydrolyzes BAME two times more rapidly than that from non-pregnant women. During pregnancy, BAME-esterase activity in plasma increases progressively up to the 40th week, decreases during labor, and after delivery reaches the same level as in non-pregnant women. The BAME-esterase activity of plasma was affected by the storage temperature, with differences demonstrable between -20 and -4 C and between pregnant and non-pregnant women. PMID:754510

  3. Combustion and heat transfer in a high speed diesel engine operating with rape seed oil methyl ester fuel

    NASA Astrophysics Data System (ADS)

    Turunen, R.

    The properties of RME (rape seed oil methyl ester) as a fuel for a diesel engine have been investigated theoretically and experimentally. The experiments were made with a turbocharged high-speed DI engine. During experiments the specific fuel consumption, exhaust gas emissions, heat release rate, flame temperature and the temperatures of the combustion chamber walls were measured. A test was also made using the measured flame temperature as an initial value for a two-zone combustion model. The theoretical investigations show that it is possible to achieve with RME approximately the same power as with ordinary diesel fuel from the same cylinder volume. The fuels give very similar theoretical (ideal) working cycles and also the efficiencies of the cycles are very near to each other.

  4. N-3-Methylbutanoyl-O-methylpropanoyl-L-serine Methyl Ester - Pheromone Component of Western Black Widow Females.

    PubMed

    Scott, Catherine; McCann, Sean; Gries, Regine; Khaskin, Grigori; Gries, Gerhard

    2015-05-01

    Chemical communication is common in spiders but few pheromones have been identified. Female widow spiders in the genus Latrodectus spin webs that disseminate an attractive sex pheromone, and a contact pheromone on the silk elicits courtship behavior by males. The methyl ester of N-3-methylbutanoyl-O-(S)-2-methylbutanoyl-L-serine is a contact pheromone of the Australian redback spider Latrodectus hasselti. We hypothesized that the contact pheromone of congeneric L. hesperus resembles that of L. hasselti. The silk of virgin L. hesperus females was extracted with methanol, and analyses by gas chromatography-mass spectrometry (GC/MS) provided evidence for the presence of N-3-methylbutanoyl-O-methylpropanoyl-L-serine methyl ester (MB-MP-S), a lower homologue of the L. hasselti contact pheromone. Behavioral responses of L. hesperus males to test stimuli were assayed on T-shaped rods with the end sections of the horizontal arm enveloped in filter paper. Males spent 40 % longer in contact with paper bearing female silk than with blank paper, and 39 % longer in contact with paper treated with silk extract than with solvent controls. Contact with silk and silk extract induced courtship behavior by 96 % and 80 % of males, respectively, indicating that there was a methanol-soluble courtship-eliciting contact pheromone on the silk. Males responded less strongly to synthetic MB-MP-S than to silk or silk extract. Paper impregnated with synthetic MB-MP-S (10 or 100 μg) induced courtship behavior in 3-16 % of males, and prompted males to stay 10-16 % longer than on control paper. Our data support the conclusion that MB-MP-S is part of a multi-component contact pheromone of L. hesperus. PMID:25940849

  5. Determination of Chlorophenoxy Acid Methyl Esters and Other Chlorinated Herbicides by GC High-resolution QTOFMS and Soft lonization

    PubMed Central

    Lopez-Avila, Viorica; Roach, Patrick; Urdahl, Randall

    2015-01-01

    Gas chromatography with quadrupole time-of-flight mass spectrometry (GC-QTOFMS) and soft ionization generated by a rare-gas plasma is described here for the determination of various chlorophenoxy acid methyl esters and a few chlorinated herbicides. This plasma-based, wavelength-selectable ionization source, which can use Xe, Kr, Ar, Ne, or He as the plasma gas, enables ionization of GC-amenable compounds with ionization energies below 8.4, 10, 11.6, 16.5, or 22.4 eV, respectively. The advantages of soft ionization include enhanced molecular ions, reduced fragmentation, and reduced background noise as compared to electron ionization. In the study presented here for two plasma gases, we demonstrate that Kr plasma, which is softer than Ar plasma, yields molecular ions with a relative intensity >60% for 11 of the 16 test compounds. When using this “tunable” plasma to ionize the analytes, there is the possibility for selective ionization and less fragmentation, which may lead to increased sensitivity and may help structure elucidation, especially when using high-resolution mass spectrometry that generates accurate masses within a few parts per million (ppm) mass errors. Data generated with the Ar plasma and real matrices such as a peppermint extract, a plum extract, and an orange peel extract, spiked with 16 test compounds, indicate that the test compounds can be detected at 1–10 pg/μL of extract, and compounds such as menthone, limonene, eucalyptol, pinene, caryophylene, and other C15H24 isomers, which are present in the peppermint and the orange peel extracts at ppm to percent levels, do not appear to interfere with the determination of the chlorophenoxy acid methyl esters or the chlorinated herbicides, although there were matrix effects when the test compounds were spiked at 1–10 pg/μL of extract. PMID:25698878

  6. Electron-transfer reaction of cinnamic acids and their methyl esters with the DPPH(*) radical in alcoholic solutions.

    PubMed

    Foti, Mario C; Daquino, Carmelo; Geraci, Corrada

    2004-04-01

    The kinetic behavior of cinnamic acids, their methyl esters, and two catechols 1-10 (ArOH) in the reaction with DPPH(*) in methanol and ethanol is not compatible with a reaction mechanism that involves hydrogen atom abstraction from the hydroxyl group of 1-10 by DPPH(*). The rate of this reaction at 25 degrees C is, in fact, comparatively fast despite that the phenolic OH group of ArOH is hydrogen bonded to solvent molecules. The observed rate constants (k(1)) relative to DPPH(*) + ArOH are 3-5 times larger for the methyl esters than for the corresponding free acids and, for the latter, decrease as their concentration is increased according to the relation k(1) = B/[ArOH](0)(m), where k(1) is given in units of M(-1) s(-1), m is ca. 0.5, and B ranges from 0.02 (p-coumaric acid) to ca. 3.48 (caffeic acid) in methanol and from 0.04 (p-coumaric acid) to ca. 13 (sinapic acid) in ethanol. Apparently, the reaction mechanism of DPPH(*) + ArOH involves a fast electron-transfer process from the phenoxide anion of 1-10 to DPPH(*). Kinetic analysis of the reaction sequence for the free acids leads to an expression for the observed rate constant, k(1), proportional to [ArOH](0)(-1/2) in excellent agreement with the experimental behavior of these phenols. The experimental results are also interpreted in terms of the influence that adventitious acids or bases present in the solvent may have. These impurities dramatically influence the ionization equilibrium of phenols and cause a reduction or an enhancement, respectively, of the measured rate constants. PMID:15049623

  7. Ubiquitin vinyl methyl ester binding orients the misaligned active site of the ubiquitin hydrolase UCHL1 into productive conformation

    SciTech Connect

    Boudreaux, David A.; Maiti, Tushar K.; Davies, Christopher W.; Das, Chittaranjan

    2010-07-06

    Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a Parkinson disease-associated, putative cysteine protease found abundantly and selectively expressed in neurons. The crystal structure of apo UCHL1 showed that the active-site residues are not aligned in a canonical form, with the nucleophilic cysteine being 7.7 {angstrom} from the general base histidine, an arrangement consistent with an inactive form of the enzyme. Here we report the crystal structures of the wild type and two Parkinson disease-associated variants of the enzyme, S18Y and I93M, bound to a ubiquitin-based suicide substrate, ubiquitin vinyl methyl ester. These structures reveal that ubiquitin vinyl methyl ester binds primarily at two sites on the enzyme, with its carboxy terminus at the active site and with its amino-terminal {beta}-hairpin at the distal site - a surface-exposed hydrophobic crevice 17 {angstrom} away from the active site. Binding at the distal site initiates a cascade of side-chain movements in the enzyme that starts at a highly conserved, surface-exposed phenylalanine and is relayed to the active site resulting in the reorientation and proximal placement of the general base within 4 {angstrom} of the catalytic cysteine, an arrangement found in productive cysteine proteases. Mutation of the distal-site, surface-exposed phenylalanine to alanine reduces ubiquitin binding and severely impairs the catalytic activity of the enzyme. These results suggest that the activity of UCHL1 may be regulated by its own substrate.

  8. Experimental study of the autoignition of C{sub 8}H{sub 16}O{sub 2} ethyl and methyl esters in a motored engine

    SciTech Connect

    Zhang, Yu.; Boehman, Andre L.

    2010-03-15

    Autoignition of two biodiesel surrogates, methyl heptanoate and ethyl hexanoate, was studied in a motored CFR engine at an equivalence ratio of 0.25 and an intake temperature of 155 C. The engine compression ratio was gradually increased from the lowest point (4.43) to the point where significant high temperature heat release (HTHR) occurred. Within the test range of this work, both of the two esters exhibited evident cool flame behavior. At the same compression ratio, methyl heptanoate was observed to have both an earlier onset and a higher magnitude of low temperature heat release (LTHR) than ethyl hexanoate, indicating that methyl heptanoate is more reactive in the low temperature region than ethyl hexanoate. GC-MS analyses of the reaction intermediates from the oxidation of the two esters showed that the alkyl chain of fatty acid esters experiences the typical paraffin-like low temperature oxidation sequence. Based on the observations from GC-MS analyses, major low temperature oxidation pathways of ethyl hexanoate are proposed in this work. Also, it is observed that the abstraction of H-atoms on the {alpha}-carbon of the ester carbonyl group plays an important role in the oxidation of fatty acid esters. In addition, the identification of hexanoic acid among the reaction intermediates from low temperature oxidation of ethyl hexanaoate together with the observation of more fuel carbon being converted to C{sub 2}H{sub 4} during ethyl hexanoate oxidation than during methyl heptanoate oxidation provide evidence for the existence of the six-centered unimolecular elimination reaction during low temperature oxidation of ethyl esters. (author)

  9. Synthesis of fatty acid methyl ester from used vegetable cooking oil by solid reusable Mg 1-x Zn 1+x O2 catalyst.

    PubMed

    Olutoye, M A; Hameed, B H

    2011-02-01

    Fatty acid methyl ester was produced from used vegetable cooking oil using Mg(1-)(x) Zn(1+)(x)O(2) solid catalyst and the performance monitored in terms of ester content obtained. Used vegetable cooking oil was employed to reduce operation cost of biodiesel. The significant operating parameters which affect the overall yield of the process were studied. The highest ester content, 80%, was achieved with the catalyst during 4h 15 min reaction at 188°C with methanol to oil ratio of 9:1 and catalyst loading of 2.55 wt% oil. Also, transesterification of virgin oil gave higher yield with the heterogeneous catalyst and showed high selectivity towards ester production. The used vegetable cooking oil did not require any rigorous pretreatment. Catalyst stability was examined and there was no leaching of the active components, and its performance was as good at the fourth as at the first cycle. PMID:21183335

  10. Pyrogenic transformation of Nannochloropsis oceanica into fatty acid methyl esters without oil extraction for estimating total lipid content.

    PubMed

    Kim, Jieun; Jung, Jong-Min; Lee, Jechan; Kim, Ki-Hyun; Choi, Tae O; Kim, Jae-Kon; Jeon, Young Jae; Kwon, Eilhann E

    2016-07-01

    This study fundamentally investigated the pseudo-catalytic transesterification of dried Nannochloropsis oceanica into fatty acid methyl esters (FAMEs) without oil extraction, which was achieved in less than 5min via a thermo-chemical pathway. This study presented that the pseudo-catalytic transesterification reaction was achieved in the presence of silica and that its main driving force was identified as temperature: pores in silica provided the numerous reaction space like a micro-reactor, where the heterogeneous reaction was developed. The introduced FAME derivatization showed an extraordinarily high tolerance of impurities (i.e., pyrolytic products and various extractives). This study also explored the thermal cracking of FAMEs derived from N. oceanica: the thermal cracking of saturated FAMEs was invulnerable at temperatures lower than 400°C. Lastly, this study reported that N. oceanica contained 14.4wt.% of dried N. oceanica and that the introduced methylation technique could be applicable to many research fields sharing the transesterification platform. PMID:27082269

  11. 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 ...

  12. Fatty Acid Methyl Ester (FAME) Succession in Different Substrates as Affected by the Co-Application of Three Pesticides

    PubMed Central

    Cardinali, Alessandra; Pizzeghello, Diego; Zanin, Giuseppe

    2015-01-01

    Introduction In intensive agriculture areas the use of pesticides can alter soil properties and microbial community structure with the risk of reducing soil quality. Materials and Methods In this study the fatty acid methyl esters (FAMEs) evolution has been studied in a factorial lab experiment combining five substrates (a soil, two aged composts and their mixtures) treated with a co-application of three pesticides (azoxystrobin, chlorotoluron and epoxiconazole), with two extraction methods, and two incubation times (0 and 58 days). FAMEs extraction followed the microbial identification system (MIDI) and ester-linked method (EL). Results and Discussion The pesticides showed high persistence, as revealed by half-life (t1/2) values ranging from 168 to 298 days, which confirms their recalcitrance to degradation. However, t1/2 values were affected by substrate and compost age down to 8 days for chlorotoluron in S and up to 453 days for epoxiconazole in 12M. Fifty-six FAMEs were detected. Analysis of variance (ANOVA) showed that the EL method detected a higher number of FAMEs and unique FAMEs than the MIDI one, whereas principal component analysis (PCA) highlighted that the monosaturated 18:1ω9c and cyclopropane 19:0ω10c/19ω6 were the most significant FAMEs grouping by extraction method. The cyclopropyl to monoenoic acids ratio evidenced higher stress conditions when pesticides were applied to compost and compost+soil than solely soil, as well as with final time. Conclusion Overall, FAMEs profiles showed the importance of the extraction method for both substrate and incubation time, the t1/2 values highlighted the effectiveness of solely soil and the less mature compost in reducing the persistence of pesticides. PMID:26694029

  13. Gas chromatography with tandem differential mobility spectrometry of fatty acid alkyl esters and the selective detection of methyl linolenate in biodiesels by dual-stage ion filtering.

    PubMed

    Pasupuleti, D; Pierce, K; Eiceman, G A

    2015-11-20

    Alkyl esters of fatty acids (FAAEs) with carbon numbers from 8 to 20 formed protonated monomers and proton bound dimers through atmospheric pressure chemical ionization reactions and these gas ions were characterized for their field dependent mobility coefficients using differential mobility spectrometry (DMS). Separation of ion peaks with a vapor modifier was achieved for ions with masses of 317-1033 Da though the differences in these coefficients and the resolution of ion peaks decreased proportionally with increased ion mass. Differences in dispersion curves were sufficient to isolate ions from specific FAAEs in the effluent of a gas chromatograph by dual stage ion filtering using a tandem DMS detector. Methyl linolenate was isolated from nearby eluting methyl oleate, methyl stearate and methyl linoleate within analysis times of 10s without measureable complications from charge suppression in the ion source or leakage in filtering of ions with close proximity of dispersion behavior. PMID:26427321

  14. Thermo-Mechanical Properties of Semi-Degradable Poly(β-amino ester)-co-Methyl Methacrylate Networks under Simulated Physiological Conditions

    PubMed Central

    Safranski, David L.; Crabtree, Jacob C.; Huq, Yameen R.; Gall, Ken

    2011-01-01

    Poly(β-amino ester) networks are being explored for biomedical applications, but they may lack the mechanical properties necessary for long term implantation. The objective of this study is to evaluate the effect of adding methyl methacrylate on networks' mechanical properties under simulated physiological conditions. The networks were synthesized in two parts: (1) a biodegradable crosslinker was formed from a diacrylate and amine, (2) and then varying concentrations of methyl methacrylate were added prior to photopolymerizing the network. Degradation rate, mechanical properties, and glass transition temperature were studied as a function of methyl methacrylate composition. The crosslinking density played a limited role on mechanical properties for these networks, but increasing methyl methacrylate concentration improved the toughness by several orders of magnitude. Under simulated physiological conditions, networks showed increasing toughness or sustained toughness as degradation occurred. This work establishes a method of creating degradable networks with tailorable toughness while undergoing partial degradation. PMID:21966028

  15. C18:1 Methyl Ester Metathesis in [bmim][X] Type Ionic Liquids

    PubMed Central

    Thomas, Priya A.; Marvey, Bassie B.

    2009-01-01

    The efficacy of [bmim][X] ionic liquids (ILs) (X = PF6−, BF4− and NTf2−) as reaction media for methyl oleate metathesis was compared with that of conventional organic solvents (PhCl, PhMe, DCM and DCE) using the well-defined first and second generation Grubbs precatalysts, RuCl2(PCy3)(L)(=CHPh) (L = PCy3 or H2IMes). Best catalytic performance, with excellent selectivity (>98%) at moderate reaction temperatures, was achieved in [bmim][X] ILs compared to conventional solvents. The effects of anion, reaction temperature, solvent polarity, solvent viscosity, and ligand-anion interaction on the reaction are also addressed. PMID:20087475

  16. Identification of jasmonic acid and its methyl ester as gum-inducing factors in tulips.

    PubMed

    Skrzypek, Edyta; Miyamoto, Kensuke; Saniewski, Marian; Ueda, Junichi

    2005-02-01

    The purpose of this study was to identify endogenous factors that induce gummosis and to show their role in gummosis in tulip (Tulipa gesneriana L. cv. Apeldoorn) stems. Using procedures to detect endogenous factors that induce gum in the stem of tulips, jasmonic acid (JA) and methyl jasmonate (JA-Me) were successfully identified using gas-liquid chromatography-mass spectrometry. Total amounts of JA and JA-Me designated as jasmonates in tulip stems were also estimated at about 70-80 ng/g fresh weight, using deuterium-labeled jasmonates as internal standards. The application of JA and JA-Me as lanolin pastes substantially induced gums in tulip stems with ethylene production. The application of ethephon, an ethylene-generating compound, however, induced no gummosis although it slightly affected jasmonate content in tulip stems. These results strongly suggest that JA and JA-Me are endogenous factors that induce gummosis in tulip stems. PMID:15654503

  17. Synthesis of theanine from glutamic acid gamma-methyl ester and ethylamine catalyzed by Escherichia coli having gamma-glutamyltranspeptidase activity.

    PubMed

    Zhang, Fei; Zheng, Qing-Zhong; Jiao, Qing-Cai; Liu, Jun-Zhong; Zhao, Gen-Hai

    2010-08-01

    Glutamic acid gamma-methyl ester (GAME) was used as substrate for theanine synthesis catalyzed by Escherichia coli cells possessing gamma-glutamyltranspeptidase activity. The yield was about 1.2-fold higher than with glutamine as substrate. The reaction was optimal at pH 10 and 45 degrees C, and the optimal substrate ratio of GAME to ethylamine was 1:10 (mol/mol). With GAME at 100 mmol, 95 mmol theanine was obtained after 8 h. PMID:20383735

  18. Anti-Diabetic and Hepato-Renal Protective Effects of Ziyuglycoside II Methyl Ester in Type 2 Diabetic Mice

    PubMed Central

    Son, Dong Ju; Hwang, Seock Yeon; Kim, Myung-Hyun; Park, Un Kyu; Kim, Byoung Soo

    2015-01-01

    Type 2 diabetes is a metabolic disorder caused by abnormal carbohydrate metabolism, and closely associated with abnormal lipid metabolism and hepato-renal dysfunction. This study investigated the anti-diabetic and hepato-renal protective properties of ziyuglycoside I (ZG01) derivative on type 2 diabetes. ZG01 was isolated from roots of Sanguisorba officinalis and chemically modified by deglycosylation and esterification to obtained ziyuglycoside II methyl ester (ZG02-ME). Here, we showed that ZG02-ME has stronger anti-diabetic activity than the original compound (ZG01) through decreasing blood glucose, glycated hemoglobin (HbA1c), and insulin levels in a mouse model of type 2 diabetes (db/db mice). We further found that ZG02-ME treatment effectively ameliorated serum insulin, leptin and C-peptide levels, which are key metabolic hormones, in db/db mice. In addition, we showed that elevated basal blood lipid levels were decreased by ZG02-ME treatment in db/db mice. Furthermore, treatment of ZG02-ME significantly decreased serum AST, ALT, BUN, creatinine, and liver lipid peroxidation in db/db mice. These results demonstrated that compared to ZG01, chemically modified ZG02-ME possess improved anti-diabetic properties, and has hepato-renal protective activities in type 2 diabetes. PMID:26198246

  19. Clearance of protoporphyrin IX from mouse skin after topical application of 5-aminolevulinic acid and its methyl ester

    NASA Astrophysics Data System (ADS)

    Juzenas, Petras; Sorensen, Roar; Iani, Vladimir; Moan, Johan

    1999-02-01

    The clearance of protoporphyrin IX (PpIX) from the skin of hairless BALB/c mice after topical application of 5- aminolevulinic acid (ALA) and its methyl ester (ALA-Me) was investigated. Creams containing 2 or 20% of ALA or ALA-Me were topically applied on spots of approximately 1 cm2 for 12 hours. The PpIX fluorescence was detected by the means of a Perkin Elmer LS50B luminescence spectrometer equipped with a fiber-optic probe. The emission spectrum was identical with that of cell-bound PpIX. After 12 hours application of ALA and ALA-Me similar amounts of PpIX were found. After creme removal the ALA-induced PpIX fluorescence decayed with a half-life of about 20 hours (20% ALA cream). The ALA-Me-induced PpIX was faster cleared from the skin than ALA-induced PpIX, and had a half-life of about 7 hours (20% ALA-Me cream).

  20. Surface-directed spinodal decomposition in poly[3-hexylthiophene] and C₆₁-butyric acid methyl ester blends.

    PubMed

    Vaynzof, Yana; Kabra, Dinesh; Zhao, Lihong; Chua, Lay Lay; Steiner, Ullrich; Friend, Richard H

    2011-01-25

    Demixed blends of poly[3-hexylthiophene] (P3HT) and C₆₁-butyric acid methyl ester (PCBM) are widely used in photovoltaic diodes (PV) and show excellent quantum efficiency and charge collection properties. We find the empirically optimized literature process conditions give rise to demixing during solvent (chlorobenzene) evaporation by spinodal decomposition. Ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS) results are consistent with the formation of 1-2 nm thick surface layers on both interfaces, which trigger the formation of surface-directed waves emanating from both film surfaces. This observation is evidence that spinodal demixing (leading to a bicontinuous phase morphology) precedes the crystallization of the two components. We propose a model for the interplay of demixing and crystallization which explains the broadly similar PV performance for devices made with the bottom electrodes either as hole or electron collector. The process regime of temporal separation of demixing and crystallization is attractive because it provides a way to control the morphology and thereby the efficiency of PV devices. PMID:21189029

  1. Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

    PubMed

    Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

    2016-06-01

    Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells. PMID:27108344

  2. S-(−)-10,11-Dihydroxyfarnesoic Acid Methyl Ester Inhibits Melanin Synthesis in Murine Melanocyte Cells

    PubMed Central

    Baek, Seung-Hwa; Ahn, Jun-Won; Nam, Sung-Hee; Yoon, Cheol-Sik; Shin, Jae-Cheon; Lee, Sang-Han

    2014-01-01

    The development of antimelanogenic agents is important for the prevention of serious aesthetic problems such as melasmas, freckles, age spots, and chloasmas. In the course of screening for melanin synthesis inhibitors, we found that the culture broth from an insect morphopathogenic fungus, Beauveria bassiana CS1029, exhibits potent antimelanogenic activity. We isolated and purified an active metabolite and identified it as S-(−)-10,11-dihydroxyfarnesoic acid methyl ester (dhFAME), an insect juvenile hormone. To address whether dhFAME inhibits melanin synthesis, we first measured the size of the melanin biosynthesis inhibition zone caused by dhFAME. dhFAME also showed inhibitory activity against mushroom tyrosinase in Melan-a cells. Intracellular, dose-dependent tyrosinase inhibition activity was also confirmed by zymography. In addition, we showed that dhFAME strongly inhibits melanin synthesis in Melan-a cells. Furthermore, we compared levels of TYR, TRP-1, TRP-2, MITF, and MC1R mRNA expression by reverse-transcription polymerase chain reaction and showed that treatment of Melan-a cells with 35 μM 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

  3. Photodynamic inactivation of Klebsiella pneumoniae biofilms and planktonic cells by 5-aminolevulinic acid and 5-aminolevulinic acid methyl ester.

    PubMed

    Liu, Chengcheng; Zhou, Yingli; Wang, Li; Han, Lei; Lei, Jin'e; Ishaq, Hafiz Muhammad; Nair, Sean P; Xu, Jiru

    2016-04-01

    The treatment of Klebsiella pneumoniae, particularly extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae, is currently a great challenge. Photodynamic antimicrobial chemotherapy is a promising approach for killing antibiotic-resistant bacteria. The aim of this study was to evaluate the capacity of 5-aminolevulinic acid (5-ALA) and its derivative 5-ALA methyl ester (MAL) in the presence of white light to cause photodynamic inactivation (PDI) of K. pneumoniae planktonic and biofilm cells. In the presence of white light, 5-ALA and MAL inactivated planktonic cells in a concentration-dependent manner. Biofilms were also sensitive to 5-ALA and MAL-mediated PDI. The mechanisms by which 5-ALA and MAL caused PDI of ESBL-producing K. pneumonia were also investigated. Exposure of K. pneumonia to light in the presence of either 5-ALA or MAL induced cleavage of genomic DNA and the rapid release of intracellular biopolymers. Intensely denatured cytoplasmic contents and aggregated ribosomes were also detected by transmission electron microscopy. Scanning electron microscopy showed that PDI of biofilms caused aggregated bacteria to detach and that the bacterial cell envelope was damaged. This study provides insights into 5-ALA and MAL-mediated PDI of ESBL-producing K. pneumoniae. PMID:26886586

  4. Cavitation assisted synthesis of fatty acid methyl esters from sustainable feedstock in presence of heterogeneous catalyst using two step process.

    PubMed

    Dubey, Sumit M; Gole, Vitthal L; Gogate, Parag R

    2015-03-01

    The present work reports the intensification aspects for the synthesis of fatty acid methyl esters (FAME) from a non-edible high acid value Nagchampa oil (31 mg of KOH/g of oil) using two stage acid esterification (catalyzed by H₂SO₄) followed by transesterification in the presence of heterogeneous catalyst (CaO). Intensification aspects of both stages have been investigated using sonochemical reactors and the obtained degree of intensification has been established by comparison with the conventional approach based on mechanical agitation. It has been observed that reaction temperature for esterification reduced from 65 to 40 °C for the ultrasonic approach whereas there was a significant reduction in the optimum reaction time for transesterification from 4h for the conventional approach to 2.5h for the ultrasound assisted approach. Also the reaction temperature reduced marginally from 65 to 60 °C and yield increased from 76% to 79% for the ultrasound assisted approach. Energy requirement and activation energy for both esterification and transesterification was lower for the ultrasound based approach as compared to the conventional approach. The present work has clearly established the intensification obtained due to the use of ultrasound and also illustrated the two step approach for the synthesis of FAME from high acid value feedstock based on the use of heterogeneous catalyst for the transesterification step. PMID:25224854

  5. Fast and accurate preparation fatty acid methyl esters by microwave-assisted derivatization in the yeast Saccharomyces cerevisiae.

    PubMed

    Khoomrung, Sakda; Chumnanpuen, Pramote; Jansa-ard, Suwanee; Nookaew, Intawat; Nielsen, Jens

    2012-06-01

    We present a fast and accurate method for preparation of fatty acid methyl esters (FAMEs) using microwave-assisted derivatization of fatty acids present in yeast samples. The esterification of free/bound fatty acids to FAMEs was completed within 5 min, which is 24 times faster than with conventional heating methods. The developed method was validated in two ways: (1) through comparison with a conventional method (hot plate) and (2) through validation with the standard reference material (SRM) 3275-2 omega-3 and omega-6 fatty acids in fish oil (from the Nation Institute of Standards and Technology, USA). There were no significant differences (P>0.05) in yields of FAMEs with both validations. By performing a simple modification of closed-vessel microwave heating, it was possible to carry out the esterification in Pyrex glass tubes kept inside the closed vessel. Hereby, we are able to increase the number of sample preparations to several hundred samples per day as the time for preparation of reused vessels was eliminated. Pretreated cell disruption steps are not required, since the direct FAME preparation provides equally quantitative results. The new microwave-assisted derivatization method facilitates the preparation of FAMEs directly from yeast cells, but the method is likely to also be applicable for other biological samples. PMID:22569641

  6. Effects of Turbulence on the Combustion Properties of Partially Premixed Flames of Canola Methyl Ester and Diesel Blends

    DOE PAGESBeta

    Dhamale, N.; Parthasarathy, R. N.; Gollahalli, S. R.

    2011-01-01

    Canola methyl ester (CME) is a biofuel that is a renewable alternative energy resource and is produced by the transesterification of canola oil. The objective of this study was to document the effects of turbulence on the combustion characteristics of blends of CME and No 2 diesel fuel in a partially-premixed flame environment. The experiments were conducted with mixtures of pre-vaporized fuel and air at an initial equivalence ratio of 7 and three burner exit Reynolds numbers, 2700, 3600, and 4500. Three blends with 25, 50, and 75% volume concentration of CME were studied. The soot volume fraction was highestmore » for the pure diesel flames and did not change significantly with Reynolds number due to the mutually compensating effects of increased carbon input rate and increased air entrainment as the Reynolds number was increased. The global NOx emission index was highest and the CO emission index was the lowest for the pure CME flame, and varied non-monotonically with biofuel content in the blend The mean temperature and the NOx concentration at three-quarter flame height were generally correlated, indicating that the thermal mechanism of NOx formation was dominant in the turbulent biofuel flames also.« less

  7. Biocatalytic Resolution of Rac-α-Ethyl-2-Oxo-Pyrrolidineacetic Acid Methyl Ester by Immobilized Recombinant Bacillus cereus Esterase.

    PubMed

    Zheng, Jian-Yong; Liu, Yin-Yan; Luo, Wei-Feng; Zheng, Ren-Chao; Ying, Xiang-Xian; Wang, Zhao

    2016-04-01

    A new esterase-producing strain (Bacillus cereus WZZ001) which exhibiting high hydrolytic activity and excellent enantioselectivity on rac-α-ethyl-2-oxo-pyrrolidineacetic acid methyl ester (R, S-1) has been isolated from soil sample by our laboratory. In this study, the stereoselective hydrolysis of (R, S-1) was performed using the recombinant Bacillus cereus esterase which expressed in Escherichia coli BL21 (DE3). Under the optimized conditions of pH 8.0, 35 °C, and concentration of substrate 400 mM, a successful enzymatic resolution was achieved with an e.e. s of 99.5 % and conversion of 49 %. Immobilization considerably increased the reusability of the recombinant esterase; the immobilized enzyme showed excellent reusability during 6 cycles of repeated 2 h reactions at 35 °C. Thereby, it makes the recombinant B. cereus esterase a usable biocatalyst for industrial application. PMID:26695776

  8. Evaluation of the separation characteristics of application-specific (fatty acid methyl esters) open-tubular columns for gas chromatography.

    PubMed

    Kiridena, Waruna; Qian, Jing; Koziol, Wladyslaw W; Poole, Colin F

    2007-03-01

    The solvation parameter model is used to characterize the separation properties of the polar stationary phases EC-Wax and PAG with a poly(ethylene oxide) backbone (substituted with propylene oxide in the case of PAG) and the cyanopropyl-substituted polysilphenylene-siloxane stationary phase BPX90 at five equally spaced temperatures between 60 and 140 degrees C. The separation characteristics of these stationary phases are compared to four PEG and two poly(cyanopropylsiloxane) stationary phases (HP-20M, HP-Innowax, SolGel-Wax, DB-WAXetr, HP-88, and SP-2340) characterized in the same way. The database of system constants for these polar stationary phases is used to provide insight into the separation mechanism for fatty acid methyl esters and to determine selectivity differences that can be expected for generically similar stationary phase types. The discussion is not structured to indicate which stationary phase should be used for a particular separation but to provide a general framework to demonstrate the relationship between the retention mechanism and stationary phase chemistry. PMID:17461115

  9. An experimental study of gaseous exhaust emissions of diesel engine using blend of natural fatty acid methyl ester

    NASA Astrophysics Data System (ADS)

    Sudrajad, Agung; Ali, Ismail; Samo, Khalid; Faturachman, Danny

    2012-09-01

    Vegetable oil form in Natural Fatty Acid Methyl Ester (FAME) has their own advantages: first of all they are available everywhere in the world. Secondly, they are renewable as the vegetables which produce oil seeds can be planted year after year. Thirdly, they are friendly with our environment, as they seldom contain sulphur element in them. This makes vegetable fuel studies become current among the various popular investigations. This study is attempt to optimization of using blend FAME on diesel engine by experimental laboratory. The investigation experimental project is comparison between using blend FAME and base diesel fuel. The engine experiment is conducted with YANMAR TF120M single cylinder four stroke diesel engine set-up at variable engine speed with constant load. The data have been taken at each point of engine speed during the stabilized engine-operating regime. Measurement of emissions parameters at difference engine speed conditions have generally indicated lower in emission NOx, but slightly higher on CO2 emission. The result also shown that the blends FAME are good in fuel consumption and potentially good substitute fuels for diesel engine

  10. Anti-Diabetic and Hepato-Renal Protective Effects of Ziyuglycoside II Methyl Ester in Type 2 Diabetic Mice.

    PubMed

    Son, Dong Ju; Hwang, Seock Yeon; Kim, Myung-Hyun; Park, Un Kyu; Kim, Byoung Soo

    2015-07-01

    Type 2 diabetes is a metabolic disorder caused by abnormal carbohydrate metabolism, and closely associated with abnormal lipid metabolism and hepato-renal dysfunction. This study investigated the anti-diabetic and hepato-renal protective properties of ziyuglycoside I (ZG01) derivative on type 2 diabetes. ZG01 was isolated from roots of Sanguisorba officinalis and chemically modified by deglycosylation and esterification to obtained ziyuglycoside II methyl ester (ZG02-ME). Here, we showed that ZG02-ME has stronger anti-diabetic activity than the original compound (ZG01) through decreasing blood glucose, glycated hemoglobin (HbA1c), and insulin levels in a mouse model of type 2 diabetes (db/db mice). We further found that ZG02-ME treatment effectively ameliorated serum insulin, leptin and C-peptide levels, which are key metabolic hormones, in db/db mice. In addition, we showed that elevated basal blood lipid levels were decreased by ZG02-ME treatment in db/db mice. Furthermore, treatment of ZG02-ME significantly decreased serum AST, ALT, BUN, creatinine, and liver lipid peroxidation in db/db mice. These results demonstrated that compared to ZG01, chemically modified ZG02-ME possess improved anti-diabetic properties, and has hepato-renal protective activities in type 2 diabetes. PMID:26198246

  11. Characterization of mycosporine-serine-glycine methyl ester, a major mycosporine-like amino acid from dinoflagellates: a mass spectrometry study.

    PubMed

    Carignan, Mario O; Carreto, José I

    2013-08-01

    Several unknown mycosporine-like amino acids (MAAs) have been previously isolated from some cultured species of toxic dinoflagellates of the Alexandrium genus (Dinophyceae). One of them, originally called M-333, was tentatively identified as a shinorine methyl ester, but the precise nature of this compound is still unknown. Using a high-resolution reversed-phase liquid chromatography mass spectrometry analyses (HPLC/MS), we found that natural populations of the red tide dinoflagellate Prorocentrum micans Ehrenberg showed a net dominance of M-333 together with lesser amounts of other MAAs. We also documented the isolation and characterization of this MAA from natural dinoflagellate populations and from Alexandrium tamarense (Lebour) Balech cultures. Using a comparative fragmentation study in electrospray mass spectrometry between deuterated and non-deuterated M-333 compounds and synthesized mono and dimethyl esters of shinorine, this novel compound was characterized as mycosporine-serine-glycine methyl ester, a structure confirmed by nuclear magnetic resonance. These isobaric compounds can be differentiated by their fragmentation patterns in MS(3) experiments because the extension and the specific site of the methylation changed the fragmentation pathway. PMID:27007200

  12. Nitric Oxide Synthase Inhibition by NG-Nitro-l-Arginine Methyl Ester Inhibits Tumor-Induced Angiogenesis in Mammary Tumors

    PubMed Central

    Jadeski, Lorraine C.; Lala, Peeyush K.

    1999-01-01

    Using a murine breast cancer model, we earlier found a positive correlation between the expression of nitric oxide synthase (NOS) and tumor progression; treatment with inhibitors of NOS, NG-methyl-l-arginine (NMMA) and NG-nitro-l-arginine methyl ester (L-NAME), had antitumor and antimetastatic effects that were partly attributed to reduced tumor cell invasiveness. In the present study, we used a novel in vivo model of tumor angiogenesis using subcutaneous implants of tumor cells suspended in growth factor-reduced Matrigel to examine the angiogenic role of NO in a highly metastatic murine mammary adenocarcinoma cell line. This cell line, C3L5, expresses endothelial (e) NOS in vitro and in vivo, and inducible (i) NOS in vitro on stimulation with lipopolysaccharide and interferon-γ. Female C3H/HeJ mice received subcutaneous implants of growth factor-reduced Matrigel inclusive of C3L5 cells on one side, and on the contralateral side, Matrigel alone; L-NAME and D-NAME (inactive enantiomer) were subsequently administered for 14 days using osmotic minipumps. Immediately after sacrifice, implants were removed and processed for immunolocalization of eNOS and iNOS proteins, and measurement of angiogenesis. Neovascularization was quantified in sections stained with Masson’s trichrome or immunostained for the endothelial cell specific CD31 antigen. While most tumor cells and endothelial cells expressed immunoreactive eNOS protein, iNOS was localized in endothelial cells and some macrophages within the tumor-inclusive implants. Measurable angiogenesis occurred only in implants containing tumor cells. Irrespective of the method of quantification used, tumor-induced neovascularization was significantly reduced in L-NAME-treated mice relative to those treated with D-NAME. The quantity of stromal tissue was lower, but the quantity of necrotic tissue higher in L-NAME relative to D-NAME-treated animals. The total mass of viable tissue (ie, stroma and tumor cells) was lower in L

  13. Negative polarity of phenyl-C{sub 61} butyric acid methyl ester adjacent to donor macromolecule domains

    SciTech Connect

    Alley, Olivia J.; Dawidczyk, Thomas J.; Hardigree, Josué F. Martínez; Katz, Howard E.; Wu, Meng-Yin; Johns, Gary L.; Markovic, Nina; Arnold, Michael S.

    2015-01-19

    Interfacial fields within organic photovoltaics influence the movement of free charge carriers, including exciton dissociation and recombination. Open circuit voltage (V{sub oc}) 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 V{sub oc}, 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-C{sub 61} 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 V{sub oc}, 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.

  14. L-dopa methyl ester attenuates amblyopia-induced neuronal injury in visual cortex of amblyopic cat.

    PubMed

    Li, Rong; Liang, Tao; Chen, Zhaoni; Zhang, Shijun; Lin, Xing; Huang, Renbin

    2013-09-15

    In the present study, we aimed to assess the potential anti-amblyopic effects of L-dopa methyl ester (LDME) on visual cortex area 17 in an amblyopic feline model induced by monocular vision deprivation. After LDME administration, pathophysiologic and ultrastructural observations were utilized to examine the morphological changes of nerve cells in visual cortex area 17. Dopamine (DA) and its metabolite contents in visual cortex area 17 were investigated through HPLC analysis. Apoptotic cells in visual cortex area 17 were evaluated by TUNEL assay. Additionally, the c-fos expression both at gene and protein levels was assessed using RT-PCR and immunohistochemistry analyses, respectively. The contents of DA and its metabolites were elevated in visual cortex area 17. Neuronal rejuvenation which occurred in visual cortex area 17 was observed through anatomical and physiological assessments. Similarly, TUNEL results showed that neuronal apoptosis was inhibited in the visual cortex of amblyopic cats by both L-dopa and LDME therapies. Meanwhile, the c-fos expression was notably up-regulated at both the mRNA and protein levels by the treatments. These findings suggested that LDME treatment could effectively increase DA and its metabolite contents, and restrain the apoptotic process, as well as elevate the c-fos expression in nerve cells of visual cortex area 17. Taken together, LDME might ameliorate the functional cytoarchitecture in visual cortex area 17 through mechanisms that elevate DA content and increase endogenous c-fos expression, as well as inhibit neuronal lesion in visual cortex tissue. PMID:23774688

  15. Use of fatty acid methyl ester profiles for discrimination of Bacillus cereus T-strain spores grown on different media.

    PubMed

    Ehrhardt, Christopher J; Chu, Vivian; Brown, TeeCie; Simmons, Terrie L; Swan, Brandon K; Bannan, Jason; Robertson, James M

    2010-03-01

    The goal of this study was to determine if cellular fatty acid methyl ester (FAME) profiling could be used to distinguish among spore samples from a single species (Bacillus cereus T strain) that were prepared on 10 different medium formulations. To analyze profile differences and identify FAME biomarkers diagnostic for the chemical constituents in each sporulation medium, a variety of statistical techniques were used, including nonmetric multidimensional scaling (nMDS), analysis of similarities (ANOSIM), and discriminant function analysis (DFA). The results showed that one FAME biomarker, oleic acid (18:1 omega9c), was exclusively associated with spores grown on Columbia agar supplemented with sheep blood and was indicative of blood supplements that were present in the sporulation medium. For spores grown in other formulations, multivariate comparisons across several FAME biomarkers were required to discern profile differences. Clustering patterns in nMDS plots and R values from ANOSIM revealed that dissimilarities among FAME profiles were most pronounced when spores grown with disparate sources of complex additives or protein supplements were compared (R > 0.8), although other factors also contributed to FAME differences. DFA indicated that differentiation could be maximized with a targeted subset of FAME variables, and the relative contributions of branched FAME biomarkers to group dissimilarities changed when different media were compared. When taken together, these analyses indicate that B. cereus spore samples grown in different media can be resolved with FAME profiling and that this may be a useful technique for providing intelligence about the production methods of Bacillus organisms in a forensic investigation. PMID:20097814

  16. Use of Fatty Acid Methyl Ester Profiles for Discrimination of Bacillus cereus T-Strain Spores Grown on Different Media▿

    PubMed Central

    Ehrhardt, Christopher J.; Chu, Vivian; Brown, TeeCie; Simmons, Terrie L.; Swan, Brandon K.; Bannan, Jason; Robertson, James M.

    2010-01-01

    The goal of this study was to determine if cellular fatty acid methyl ester (FAME) profiling could be used to distinguish among spore samples from a single species (Bacillus cereus T strain) that were prepared on 10 different medium formulations. To analyze profile differences and identify FAME biomarkers diagnostic for the chemical constituents in each sporulation medium, a variety of statistical techniques were used, including nonmetric multidimensional scaling (nMDS), analysis of similarities (ANOSIM), and discriminant function analysis (DFA). The results showed that one FAME biomarker, oleic acid (18:1 ω9c), was exclusively associated with spores grown on Columbia agar supplemented with sheep blood and was indicative of blood supplements that were present in the sporulation medium. For spores grown in other formulations, multivariate comparisons across several FAME biomarkers were required to discern profile differences. Clustering patterns in nMDS plots and R values from ANOSIM revealed that dissimilarities among FAME profiles were most pronounced when spores grown with disparate sources of complex additives or protein supplements were compared (R > 0.8), although other factors also contributed to FAME differences. DFA indicated that differentiation could be maximized with a targeted subset of FAME variables, and the relative contributions of branched FAME biomarkers to group dissimilarities changed when different media were compared. When taken together, these analyses indicate that B. cereus spore samples grown in different media can be resolved with FAME profiling and that this may be a useful technique for providing intelligence about the production methods of Bacillus organisms in a forensic investigation. PMID:20097814

  17. Accurate and reliable quantification of total microalgal fuel potential as fatty acid methyl esters by in situ transesterification.

    PubMed

    Laurens, Lieve M L; Quinn, Matthew; Van Wychen, Stefanie; Templeton, David W; Wolfrum, Edward J

    2012-04-01

    In the context of algal biofuels, lipids, or better aliphatic chains of the fatty acids, are perhaps the most important constituents of algal biomass. Accurate quantification of lipids and their respective fuel yield is crucial for comparison of algal strains and growth conditions and for process monitoring. As an alternative to traditional solvent-based lipid extraction procedures, we have developed a robust whole-biomass in situ transesterification procedure for quantification of algal lipids (as fatty acid methyl esters, FAMEs) that (a) can be carried out on a small scale (using 4-7 mg of biomass), (b) is applicable to a range of different species, (c) consists of a single-step reaction, (d) is robust over a range of different temperature and time combinations, and (e) tolerant to at least 50% water in the biomass. Unlike gravimetric lipid quantification, which can over- or underestimate the lipid content, whole biomass transesterification reflects the true potential fuel yield of algal biomass. We report here on the comparison of the yield of FAMEs by using different catalysts and catalyst combinations, with the acid catalyst HCl providing a consistently high level of conversion of fatty acids with a precision of 1.9% relative standard deviation. We investigate the influence of reaction time, temperature, and biomass water content on the measured FAME content and profile for 4 different samples of algae (replete and deplete Chlorella vulgaris, replete Phaeodactylum tricornutum, and replete Nannochloropsis sp.). We conclude by demonstrating a full mass balance closure of all fatty acids around a traditional lipid extraction process. PMID:22349344

  18. Isosorbide 5-mononitrate reverses high blood pressure in NG-nitro-L-arginine methyl ester treated rats.

    PubMed

    Albino-Teixeira, A; Soares-da-Silva, P

    1994-11-01

    1. The present study has evaluated the effect of iosorbide 5-mononitrate (IS-5-MN) and L-arginine on blood pressure profile during chronic administration of the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). 2. After a 7 day period of stabilization, normotensive male Wistar rats (n = 10) were selected and given L-NAME (50 micrograms/ml) in drinking water. Control rats (n = 10) were studied simultaneously for direct comparison of cardiovascular parameters. Blood pressure (systolic, SBP; diastolic, DBP) and heart rate were measured using a photoelectric tail cuff pulse detector; SBP and DBP were, in normotensive rats 106 +/- 2 and 78 +/- 2 mmHg (n = 10), respectively. The average water consumption per animal was about 35 ml/day resulting in a mean intake of L-NAME of about 10 mg/kg/day. 3. Twenty four hours after exposure to L-NAME, both SBP and DBP were found to be increased by 20 mm Hg; heart rate slightly decreased. During the next 13 days both SBP and DBP increased progressively reaching 170 +/- 3 and 116 +/- 3 mm Hg, respectively. 4. On day 14, six animals of either group were sacrificed and the heart, kidneys, liver, spleen, mesenteric and caudal arteries, brain stem, hypothalamus and parietal cortex were taken from determination of noradrenaline and dopamine content; blood from the renal vein was also collected and plasma concentrations of noradrenaline, adrenaline and 3,4-dihydroxyphenylethylglycol (DOPEG) determined.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7896042

  19. Accurate and Reliable Quantification of Total Microalgal Fuel Potential as Fatty Acid Methyl Esters by in situ Transesterfication

    SciTech Connect

    Laurens, L. M. L.; Quinn, M.; Van Wychen, S.; Templeton, D. W.; Wolfrum, E. J.

    2012-04-01

    In the context of algal biofuels, lipids, or better aliphatic chains of the fatty acids, are perhaps the most important constituents of algal biomass. Accurate quantification of lipids and their respective fuel yield is crucial for comparison of algal strains and growth conditions and for process monitoring. As an alternative to traditional solvent-based lipid extraction procedures, we have developed a robust whole-biomass in situ transesterification procedure for quantification of algal lipids (as fatty acid methyl esters, FAMEs) that (a) can be carried out on a small scale (using 4-7 mg of biomass), (b) is applicable to a range of different species, (c) consists of a single-step reaction, (d) is robust over a range of different temperature and time combinations, and (e) tolerant to at least 50% water in the biomass. Unlike gravimetric lipid quantification, which can over- or underestimate the lipid content, whole biomass transesterification reflects the true potential fuel yield of algal biomass. We report here on the comparison of the yield of FAMEs by using different catalysts and catalyst combinations, with the acid catalyst HCl providing a consistently high level of conversion of fatty acids with a precision of 1.9% relative standard deviation. We investigate the influence of reaction time, temperature, and biomass water content on the measured FAME content and profile for 4 different samples of algae (replete and deplete Chlorella vulgaris, replete Phaeodactylum tricornutum, and replete Nannochloropsis sp.). We conclude by demonstrating a full mass balance closure of all fatty acids around a traditional lipid extraction process.

  20. Photophysics and morphology of poly (3-dodecylthienylenevinylene)-[6,6]-phenyl-C{sub 61}-butyric acid methyl ester composite

    SciTech Connect

    Lafalce, E.; Toglia, P.; Jiang, X.; Zhang, C.

    2012-05-21

    A series of low band gap poly(3-dodecylthienylenevinylene) (PTV) with controlled morphological order have been synthesized and blended with the electron acceptor [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) for organic photovoltaic devices. Two polymers with the most and least side chain regioregularity were chosen in this work, namely the PTV010 and PTV55, respectively. Using photoluminescence, photo-induced absorption spectroscopy, and atomic force microscopy, we find no direct evidence of photoinduced charge transfer between the two constituents, independent of the bulk-heterojunction morphology of the film, although the possibility of formation of P{sup +}/C{sub 60}{sup -} charge transfer complex was not completely ruled out. The large exciton binding energy (E{sub b} = 0.6 eV) in PTV inhibits the photoinduced electron transfer from PTV to PCBM. In addition, excitons formed on polymer chains suffer ultrafast (

  1. Regional and cardiac haemodynamic effects of NG-nitro-L-arginine methyl ester in conscious, Long Evans rats.

    PubMed Central

    Gardiner, S. M.; Compton, A. M.; Kemp, P. A.; Bennett, T.

    1990-01-01

    1. Regional haemodynamic responses to i.v. bolus doses (0.1-10.0 mg kg-1) of NG-nitro-L-arginine methyl ester (L-NAME) were measured in conscious, Long Evans rats (n = 8) chronically instrumented with renal, mesenteric and hindquarters pulsed Doppler flow probes and intravascular catheters. 2. L-NAME caused dose-dependent pressor effects associated with renal, mesenteric and hindquarters vasoconstrictions. The mesenteric vascular bed showed earlier onset with more rapid, and greater, maximum vasoconstrictions than the renal or hindquarters vascular beds; however, the hindquarters vasoconstriction was more persistent. D-NAME was without significant effects (n = 2). 3. Primed infusion of L-arginine (100 mg kg-1 bolus followed by 100 mg kg-1 h-1 infusion), starting 10 min after an i.v. bolus injection of L-NAME (10 mg kg-1), caused significant reversal of the pressor responses, and renal and mesenteric vasoconstrictions, but not of the hindquarters vasoconstriction. Primed infusions of L-arginine (100 mg kg-1, 100 mg kg-1 h-1) starting 5 min after L-NAME (1 mg kg-1) additionally caused some reversal of the hindquarters vasoconstriction, but this effect was transient. 4. Primed infusion of L-arginine (100 mg kg-1, 100 mg kg-1 h-1) starting 30 min before i.v. bolus injection of L-NAME (10 mg kg-1) caused significant attenuation of the pressor effects and the renal and mesenteric vasoconstrictions but not of the hindquarters vasoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2076481

  2. Synthesis, structural and conformational study of some esters derived from 3-methyl-3-azabicyclo[3.2.1]octan-8(α and β)-ols

    NASA Astrophysics Data System (ADS)

    Iriepa, I.; Bellanato, J.

    2014-09-01

    A series of α and β-esters bearing a 3-methyl-3-azabicyclo[3.2.1]octane moiety as well as methyl and aryl substituents were synthesized and studied by 1H and 13C NMR spectroscopies. In CDCl3 solution, at room temperature, a chair-envelope conformation for the bicycle moiety with the N-CH3 group in equatorial position with respect to the chair ring is proposed for both, α and β-esters. The chair conformation of the piperidine ring is puckered at C8 in the α-epimers and it is flattened at N3, in the β-epimers. Free rotation of the acyloxy group around the C8sbnd O bond has also been deduced. Analgesic activity of four of these substances was studied. 8β-Benzoyloxy-3-methyl-3-azabicyclo[3.2.1]octane demonstrated significant analgesic activity in the hot plate test compared to morphine. By measuring the rectal temperature in mice, results also showed a significant antipyretic activity of this compound.

  3. Molecularly imprinted polymer for the selective extraction of cocaine and its metabolites, benzoylecgonine and ecgonine methyl ester, from biological fluids before LC-MS analysis.

    PubMed

    Thibert, Valérie; Legeay, Patrice; Chapuis-Hugon, Florence; Pichon, Valérie

    2014-02-15

    Considering the important complexity of biological samples, a molecularly imprinted polymer (MIP) was applied to the selective extraction of cocaine and its two main metabolites, benzoylecgonine and ecgonine methyl ester from biological samples. The MIP was imprinted with cocaine and it was synthesized in acetonitrile with methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a crosslinker. The selectivity of the MIP was first assessed for the three target analytes in acetonitrile with recoveries higher than 80% on the MIP and lower than 30% on the non-imprinted polymer (NIP). The MIP was then evaluated for the selective extraction of these targets from real aqueous media, i.e. serum and urine samples. The pH adjustment of the sample as well as the optimization of the washing step led to a very selective extraction of cocaine from these media. A LOQ of 0.5ng/mL was obtained for cocaine in urine. Concerning cocaine metabolites, benzoylecgonine and ecgonine methyl ester, they were first extracted from urine by liquid-liquid extraction and the resulting extract was purified on the MIP. The results obtained with the MIP as compared to the LLE alone showed the great potential of the MIP extraction for the clean-up of the biological matrix. This procedure was tested for the extraction of the analytes from urine samples, leading to a very selective protocol with LOQs of 0.09ng/mL, 0.4ng/mL and 1.1ng/mL for cocaine, benzolecgonine and ecgonine methyl ester respectively in urine samples. PMID:24444871

  4. Molecular mechanics (MM3) study of the conformations of methyl esters and N, N-dimethylamides of diastereoisomeric 4-cyano-3,4-diphenyl-butanoic acids

    NASA Astrophysics Data System (ADS)

    Ivanov, P. M.

    2000-10-01

    Molecular mechanics (MM3 force field) was used to examine an unexpected observation by NMR for a preference of conformations with synclinal protons around the C(3)-C(4) bond in methyl esters and dimethylamides of diastereoisomeric 4-cyano-3,4-diphenyl-butanoic acids. After the reoptimization of three torsional parameters, related to structural units containing a cyano group, we obtained a good correlation between the MM3 computed populations of the conformations and the estimates from vicinal coupling constants. The electrostatic interactions have the decisive contribution for lowering the energies of the preferred conformations.

  5. Fast and simple method for determination of fatty acid methyl esters (FAME) in biodiesel blends using X-ray spectrometry.

    PubMed

    Sitko, Rafal; Zawisza, Beata; Kowalewska, Zofia; Kocot, Karina; Polowniak, Marzena

    2011-09-30

    The determination of fatty acid methyl esters (FAME) in diesel fuel blends is an important aspect of production and blending process as well as quality control of distribution operations. In this study, energy-dispersive X-ray fluorescence spectrometer (EDXRF) is used for the first time for determination of FAME in biodiesel blends. The principle of the method is based on intensity difference of X-ray radiation scattered from hydrocarbons and from FAME. The experiment shows that coherent and incoherent radiation, commonly applied for evaluation of the average atomic number of the sample with light matrix, cannot be applied for FAME determination. However, the application of scattered continuous radiation gives excellent correlation between FAME concentration and intensity of scattered radiation. The best results are obtained if continuum is collected in the range of energy between 10.5 and 15.0 keV for rhodium X-ray tube, operated at 35 kV. Linear relationship between the FAME concentration and the inverse of scattered continuous radiation is obtained with the correlation coefficients of 0.999. Standard deviation of measurement is ca. 0.46% (v/v) of FAME and detection limit is 1.2% (v/v) for 600 s counting time and 50% dead-time loss using Si-PIN detector. The investigation shows that crucial issue in determination of FAME in biodiesel blends using EDXRF spectrometer is the precision of measurements resulting from the counting statistics. Therefore, much better results (0.20% (v/v) standard deviation and 0.52% (v/v) detection limit) can be expected if higher intensity of primary radiation is applied and X-ray spectrum is collected by silicon drift detector of high input count rate. For concentration of FAME from 10 to 100% (v/v), the differences between reference method (Fourier transform infrared spectrometry) and the proposed method usually do not exceed 1% (v/v) of FAME. The proposed method is fast, simple and enables FAME determination in wide range of

  6. Use of Fatty Acid Methyl Ester Profiles to Compare Copper-Tolerant and Copper-Sensitive Strains of Pantoea ananatis.

    PubMed

    Nischwitz, C; Gitaitis, R; Sanders, H; Langston, D; Mullinix, B; Torrance, R; Boyhan, G; Zolobowska, L

    2007-10-01

    ABSTRACT A survey was conducted to evaluate differences in fatty acid methyl ester (FAME) profiles among strains of Pantoea ananatis, causal agent of center rot of onion (Allium cepa), isolated from 15 different onion cultivars in three different sites in Georgia. Differences in FAME composition were determined by plotting principal components (PCs) in two-dimensional plots. Euclidean distance squared (ED(2)) values indicated a high degree of similarity among strains. Plotting of PCs calculated from P. ananatis strains capable of growing on media amended with copper sulfate pentahydrate (200 mug/ml) indicated that copper-tolerant strains grouped into tight clusters separate from clusters formed by wild-type strains. However, unlike copper-sensitive strains, the copper-tolerant strains tended to cluster by location. A total of 80, 60, and 73% of the strains from Tift1, Tift2, and Tattnall, respectively, exhibited either confluent growth or partial growth on copper-amended medium. However, all strains were sensitive to a mixture of copper sulfate pentahydrate (200 mug/ml) and maneb (40 mug/ml). When copper-tolerant clones were analyzed and compared with their wild-type parents, in all cases the plotting of PCs developed from copper-tolerant clones formed tight clusters separate from clusters formed by the parents. Eigenvalues generated from these tests indicated that two components provided a good summary of the data, accounting for 98, 98, and 96% of the standardized variance for strains Pna 1-15B, Pna 1-12B, and Pna 2-5A, respectively. Furthermore, feature 4 (cis-9-hexadecenoic acid/2-hydroxy-13-methyltetradecanoic acid) and feature 7 (cis-9/trans-12/cis-7-octadecenoic acid) were the highest or second highest absolute values for PC1 in all three strains of the parents versus copper-tolerant clones, and hexadecanoic acid was the highest absolute value for PC2 in all three strains. Along with those fatty acids, dodecanoic acid and feature 3 (3-hydroxytetradecanoic

  7. Synthesis of 3beta-(4-[18F]fluoromethylphenyl)- and 3beta-(2-[18F] fluoromethylphenyl)tropane-2beta-carboxylic acid methyl esters: new ligands for mapping brain dopamine transporter with positron emission tomography.

    PubMed

    Petric, A; Barrio, J R; Namavari, M; Huang, S C; Satyamurthy, N

    1999-07-01

    The synthesis of two new dopamine transporter ligands, 3beta-(4-fluoromethylphenyl)tropane-2beta-carboxylic acid methyl ester and 3beta-(2-fluoromethylphenyl)tropane-2beta-carboxylic acid methyl ester, and their spectral characterization are described. The precursors for these ligands were prepared by TiCl4 catalyzed chloromethylation of 3beta-phenyltropane-2beta-carboxylic acid methyl ester followed by separation of the isomeric product mixture of 2- and 4-chloromethylphenyltropane derivatives. Reaction of the chloromethyl analogs with no-carrier-added [18F]fluoride ion followed by high performance liquid chromatography purification provided the corresponding [18F]fluoromethyltropanes, in good radiochemical yields, useful for imaging the brain dopamine transporter system in vivo with positron emission tomography. PMID:10473191

  8. Synthesis of comb type and semi-interpenetrating networks of acryloyl- L-proline methyl ester and poly (acrylic acid) for Cu (II) immobilization

    NASA Astrophysics Data System (ADS)

    González, Giovanni; Burillo, Guillermina

    2010-08-01

    Graft copolymer hydrogels and semi-interpenetrating networks (s-IPN) of acryloyl- L-proline methyl ester (A-ProOMe) and poly (acrylic acid) (PAAc) were synthesized in methanol solutions, by ionizing radiation (γ rays from a Co 60 source at room temperature). These systems are thermo and pH-sensitive and the pH sensitivity increases from acidic to basic solutions. The Lower Critical Solution Temperature (LCST), due to presence of poly (acryloyl- L-proline methyl ester) (PA-ProOMe) has been found between 18 and 20 °C and an unexpected Upper Critical Solution Temperature (UCST) due to poly acrylic acid (PAAc) has been found between 21 and 22 °C. Preliminary studies on the immobilization of Cu 2+ for both hydrogels were done at several pH values at room temperature. Other techniques employed to characterize the comb type hydrogels and sIPN included scanning electronic microscopy (SEM) and infrared (FTIR-ATR).

  9. Rhodotorula glutinis Phenylalanine/Tyrosine Ammonia Lyase Enzyme Catalyzed Synthesis of the Methyl Ester of para-Hydroxycinnamic Acid and its Potential Antibacterial Activity.

    PubMed

    MacDonald, Marybeth C; Arivalagan, Pugazhendhi; Barre, Douglas E; MacInnis, Judith A; D'Cunha, Godwin B

    2016-01-01

    Biotransformation of L-tyrosine methyl ester (L-TM) to the methyl ester of para- hydroxycinnamic acid (p-HCAM) using Rhodotorula glutinis yeast phenylalanine/tyrosine ammonia lyase (PTAL; EC 4.3.1.26) enzyme was successfully demonstrated for the first time; progress of the reaction was followed by spectrophotometric determination at 315 nm. The following conditions were optimized for maximal formation of p-HCAM: pH (8.5), temperature (37°C), speed of agitation (50 rpm), enzyme concentration (0.080 μM), and substrate concentration (0.50 mM). Under these conditions, the yield of the reaction was ∼15% in 1 h incubation period and ∼63% after an overnight (∼18 h) incubation period. The product (p-HCAM) of the reaction of PTAL with L-TM was confirmed using Nuclear Magnetic Resonance spectroscopy (NMR). Fourier Transform Infra-Red spectroscopy (FTIR) was carried out to rule out potential hydrolysis of p-HCAM during overnight incubation. Potential antibacterial activity of p-HCAM was tested against several strains of Gram-positive and Gram-negative bacteria. This study describes a synthetically useful transformation, and could have future clinical and industrial applications. PMID:27014206

  10. Rhodotorula glutinis Phenylalanine/Tyrosine Ammonia Lyase Enzyme Catalyzed Synthesis of the Methyl Ester of para-Hydroxycinnamic Acid and its Potential Antibacterial Activity

    PubMed Central

    MacDonald, Marybeth C.; Arivalagan, Pugazhendhi; Barre, Douglas E.; MacInnis, Judith A.; D’Cunha, Godwin B.

    2016-01-01

    Biotransformation of L-tyrosine methyl ester (L-TM) to the methyl ester of para- hydroxycinnamic acid (p-HCAM) using Rhodotorula glutinis yeast phenylalanine/tyrosine ammonia lyase (PTAL; EC 4.3.1.26) enzyme was successfully demonstrated for the first time; progress of the reaction was followed by spectrophotometric determination at 315 nm. The following conditions were optimized for maximal formation of p-HCAM: pH (8.5), temperature (37°C), speed of agitation (50 rpm), enzyme concentration (0.080 μM), and substrate concentration (0.50 mM). Under these conditions, the yield of the reaction was ∼15% in 1 h incubation period and ∼63% after an overnight (∼18 h) incubation period. The product (p-HCAM) of the reaction of PTAL with L-TM was confirmed using Nuclear Magnetic Resonance spectroscopy (NMR). Fourier Transform Infra-Red spectroscopy (FTIR) was carried out to rule out potential hydrolysis of p-HCAM during overnight incubation. Potential antibacterial activity of p-HCAM was tested against several strains of Gram-positive and Gram-negative bacteria. This study describes a synthetically useful transformation, and could have future clinical and industrial applications. PMID:27014206

  11. 40 CFR 721.8500 - 2-Propenoic acid, 2-methyl-, 7-oxabicyclo [4.1.0]hept-3-ylmethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 721.63 (a)(1), (a)(3), (a)(4), (a)(5)(viii), (a)(5)(xv), (a)(6)(i), (a)(6)(ii), (a)(6)(iv), (b) (concentration set at 0.1 percent), and (c). (ii) Hazard communication program. Requirements as specified in... hept-3-ylmethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1)...

  12. 40 CFR 721.8500 - 2-Propenoic acid, 2-methyl-, 7-oxabicyclo [4.1.0]hept-3-ylmethyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 721.63 (a)(1), (a)(3), (a)(4), (a)(5)(viii), (a)(5)(xv), (a)(6)(i), (a)(6)(ii), (a)(6)(iv), (b) (concentration set at 0.1 percent), and (c). (ii) Hazard communication program. Requirements as specified in... hept-3-ylmethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1)...

  13. Broadband gain in poly(3-hexylthiophene):phenyl-C{sub 61}-butyric-acid-methyl-ester photodetectors enabled by a semicontinuous gold interlayer

    SciTech Connect

    Melancon, Justin M.; Živanović, Sandra R.

    2014-10-20

    Substantial broadband photoconductive gain has been realized for organic, thin-film photodetectors with a poly(3-hexylthiophene):phenyl-C{sub 61}-butyric-acid-methyl-ester (P3HT:PCBM) active layer at low bias voltages. External quantum efficiencies upwards of 1500% were achieved when a semicontinuous gold layer was introduced at the anode interface. Significant gain was also observed in the sub-band gap, near infrared region where the external quantum efficiency approached 100% despite the lack of a sensitizer. The gain response was highly dependent on the thickness of the active layer of the photodetector with the best results achieved with the thinnest devices. The gain is the result of the injection of secondary electrons due to hole charge trapping at the semicontinuous gold layer.

  14. Modeling of Open-Circuit Voltage of Phenyl-C61-Butyric Acid Methyl Ester-Like Based Bulk-Heterojunction Solar Cells.

    PubMed

    Ferreira, Rodrigo M; Batagin-Neto, Augusto; Lavarda, Francisco C

    2015-12-01

    New materials are currently being sought for use in active layers of bulk-heterojunction organic solar cells, and computational modeling plays an important role in this search. Although open circuit voltage (V(oc)) is one of the fundamental quantities that determine the efficiency of a solar cell, there is no consensus on the best way to estimate this magnitude for new materials from calculations of the electronic structure. In this paper, we compare ways of predicting V(oc) values employing a diverse group of blends and conclude that it is possible to have a good prediction tool for organic solar cells based on phenyl-C61-butyric acid methyl ester (PCBM) acceptor molecules. PMID:26682440

  15. Noncatalytic transformation of the crude lipid of ChlorellaI vulgaris into fatty acid methyl ester (FAME) with charcoal via a thermo-chemical process.

    PubMed

    Kwon, Eilhann E; Jeon, Young Jae; Yi, Haakrho

    2013-02-01

    The noncatalytic transformation of the crude lipid of Chlorella vulgaris (C. vulgaris) into fatty acid methyl ester (FAME) via a thermo-chemical process was mainly investigated in this work. The crude lipid of C. vulgaris was recovered by means of solvent extraction from C. vulgaris cultivated in a raceway pond. The conventional catalyzed transesterification of crude lipid of C. vulgaris is notably inhibited by the impurities contained in the crude lipid of C. vulgaris. These impurities are inevitably derived from the solvent extraction process for C. vulgaris. However, this work presents the noncatalytic transesterification of microalgal lipid into FAME, which could be an alternative option. For example, the noncatalytic transformation of microalgal lipid into FAME provides evidence that the esterification of free fatty acids (FFAs) and the transesterification of triglycerides can be combined into a single step less susceptible to the impurities and with a high conversion efficiency (∼97%). PMID:23294646

  16. The use of fatty acid methyl ester analysis (FAME) for the identification of heterotrophic bacteria present on three mural paintings showing severe damage by microorganisms.

    PubMed

    Heyrman, J; Mergaert, J; Denys, R; Swings, J

    1999-12-01

    Mural paintings in Carmona (Spain), Herberstein (Austria) and Greene (Germany), showing visible deterioration by microorganisms, were sampled to investigate the biodiversity of the heterotrophic bacteria present. Four hundred twenty-eight bacterial strains were isolated from which 385 were characterized by fatty acid methyl ester analysis (FAME). The isolates were grouped into 41 clusters on the basis of their FAME profiles, 20 isolates remained ungrouped. The majority (94%) of the isolates comprised the gram-positive bacteria and the main clusters were identified as Bacillus sp., Paenibacillus sp., Micrococcus sp., Arthrobacter sp. and Staphylococcus sp. Other clusters contain nocardioform actinomycetes and gram-negative bacteria, respectively. A cluster of the latter contained extreme halotolerant bacteria isolated in Herberstein. The FAME profiles of this cluster showed a high similarity with Halomonas. PMID:10564789

  17. FTIR measurements of mid-IR absorption spectra of gaseous fatty acid methyl esters at T=25-500 °C

    NASA Astrophysics Data System (ADS)

    Campbell, M. F.; Freeman, K. G.; Davidson, D. F.; Hanson, R. K.

    2014-09-01

    Gas-phase mid-infrared (IR) absorption spectra (2500-3400 cm-1) for eleven fatty acid methyl esters (FAMEs) have been quantitatively measured at temperatures between 25 and 500 °C using an FTIR spectrometer with a resolution of 1 cm-1. Using these spectra, the absorption cross section at 3.39 μm, corresponding to the monochromatic output of a helium-neon laser, is reported for each of these fuels as a function of temperature. The data indicate that the 3.39 μm cross section values of saturated FAMEs vary linearly with the logarithm of the number of Csbnd H bonds in the molecule.

  18. Molecular structure, vibrational spectra, first order hyper polarizability, NBO and HOMO-LUMO analysis of 2-amino-5-bromo-benzoic acid methyl ester

    NASA Astrophysics Data System (ADS)

    Balamurugan, N.; Charanya, C.; SampathKrishnan, S.; Muthu, S.

    2015-02-01

    An organic crystal of 2-amino-5-bromobenzoic acid methyl ester [abbreviated at 2A5BrBAMe], single crystal, belongs to the amino acid group, were grown by the slow evaporation solution growth technique at room temperature. The grown crystal had been subjected to single-crystal X-ray diffraction technique and cell parameters of the crystal were determined. The quantitative analysis on the crystal had been carried out using Fourier transform infrared (FTIR) and Fourier transform Raman (FT-Raman) spectral measurements. The molecular structures, vibrational wave numbers were calculated using DFT (B3LYP) method with 6-311++G(d,p) basis set. The formation of the hydrogen bond was investigated using NBO calculations. The calculated HOMO and LUMO energies show that charge transfer occur within the molecule. The dipole moment (μ) and polarizability (α0), anisotropy polarizability (Δα) and first order hyperpolarizability (β0) of the molecule have been reported.

  19. Palladium(II) Complexes Containing Mixed Nitrogen-Sulphur Donor Ligands: Interaction of [Pd(Methionine Methyl Ester)(H2O)2]2+ with Biorelevant Ligands

    PubMed Central

    Shoukry, Mohamed M.; Ezzat, Sameya M. T.

    2014-01-01

    Pd(MME)Cl2 complex (MME = methionine methyl ester) was synthesised and characterized by physicochemical measurements. The reaction of [Pd(MME)(H2O)2]2+ with amino acids, peptides, or dicarboxylic acids was investigated at 25°C and 0.1 M ionic strength. Amino acids and dicarboxylic acids form 1 : 1 complexes. Peptides form both 1 : 1 complexes and the corresponding deprotonated amide species. The stability of the complexes formed was determined and the binding centres of the ligands were assigned. Effect of solvent on the stability constant of Pd(MME)-CBDCA complex, taken as a representative example, shows that the complex is more favoured in a medium of low dielectric constant. The concentration distribution diagrams of the complexes were evaluated. PMID:25214826

  20. 2-[(1H-Benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester: Crystal structure, DFT calculations and biological activity evaluation

    NASA Astrophysics Data System (ADS)

    Ghani, Nour T. Abdel; Mansour, Ahmed M.

    2011-10-01

    In the present study, structural properties of 2-[(1H-benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester have been studied extensively by spectral methods and X-ray crystallography. Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, NMR and electronic transitions were carried out by DFT using B3LYP functional combined with 6-31G(d) basis set. Natural bond orbitals (NBO) analysis and frontier molecular orbitals were performed at the same level of theory. DFT calculations showed good agreement between the theoretical and experimental values of optimized and X-ray structure as well as between the vibrational and NMR spectroscopy. The title compound was screened for its antibacterial activity referring to Tetracycline as standard antibacterial agent.

  1. Synthesis of fatty acid methyl ester from palm oil (Elaeis guineensis) with Ky(MgCa)2xO3 as heterogeneous catalyst.

    PubMed

    Olutoye, M A; Lee, S C; Hameed, B H

    2011-12-01

    Fatty acid methyl esters (FAME) were produced from palm oil using eggshell modified with magnesium and potassium nitrates to form a composite, low-cost heterogeneous catalyst for transesterification. The catalyst, prepared by the combination of impregnation/co-precipitation was calcined at 830 °C for 4 h. Transesterification was conducted at a constant temperature of 65 °C in a batch reactor. Design of experiment (DOE) was used to optimize the reaction parameters, and the conditions that gave highest yield of FAME (85.8%) was 5.35 wt.% catalyst loading at 4.5 h with 16:1 methanol/oil molar ratio. The results revealed that eggshell, a solid waste, can be utilized as low-cost catalyst after modification with magnesium and potassium nitrates for biodiesel production. PMID:21983406

  2. On the Inapplicability of Electron-Hopping Models for the Organic Semiconductor Phenyl-C61-butyric Acid Methyl Ester (PCBM).

    PubMed

    Gajdos, Fruzsina; Oberhofer, Harald; Dupuis, Michel; Blumberger, Jochen

    2013-03-21

    Phenyl-C61-butyric acid methyl ester (PCBM) is one of the most popular semiconductors in organic photovoltaic cells, but the electron-transport mechanism in the microcrystalline domains of this material as well as its preferred packing structure remain unclear. Here we use density functional theory to calculate electronic-coupling matrix elements, reorganization energies, and activation energies for available experimental and model crystal structures. We find that the picture of an excess electron hopping from one fullerene to another does not apply for any of the crystalline phases, rendering traditional rate equations inappropriate. We also find that the cohesive energy increases in the order body-centered-cubic < hexagonal < simple cubic < monoclinic < triclinic, independently of the type of dispersion correction used. Our results indicate that the coupled electron-ion dynamics needs to be solved explicitly to obtain a realistic description of charge transfer in this material. PMID:26291369

  3. Synthesis and structure activity relationship studies of 3-biaryl-8-oxa-bicyclo[3.2.1]octane-2-carboxylic acid methyl esters

    PubMed Central

    Torun, Lokman; Madras, Bertha K.; Meltzer, Peter C.

    2012-01-01

    Stille cross coupling protocols were utilized for the synthesis of 3-(biaryl)-8-oxabicyclo[3.2.1]oct-2-ene-2-carboxylic acid methyl esters, which furnished products in high yields where in some cases Suzuki coupling under the conditions utilized provided complex reaction mixture. Samarium iodide reduction of the resulting coupling products produced both of the 2β-carbomethoxy-3-biaryl-8-oxabicyclo[3.2.1]octane diastereomers and the 2α-carbomethoxy-3-biaryl-8-oxabicyclo[3.2.1]octane diastereomers. Among the series synthesized, the benzothiophene substituted compounds demonstrated significant binding profiles of inhibition of WIN 35,438 with 177 fold selectivity for DAT vs. SERT. PMID:22398259

  4. Towards Solvation of a Chiral Alpha-Hydroxy Ester: Broadband Chirp and Narrow Band Cavity Fouirier Transform Microwave Spectroscopy of Methyl Lactate-Water Clusters

    NASA Astrophysics Data System (ADS)

    Thomas, Javix; Sukhorukov, Oleksandr; Jaeger, Wolfgang; Xu, Yunjie

    2013-06-01

    Methyl lactate (ML), a chiral alpha-hydroxy ester, has attracted much attention as a prototype system in studies of chirality transfer,[1] solvation effects on chiroptical signatures,[2] and chirality recognition.[3] It has multiple functional groups which can serve both as a hydrogen donor and acceptor. By applying rotational spectroscopy and high level ab initio calculations, we examine the delicate competition between inter- and intramolecular hydrogen-bonding in the ML-water clusters. Broadband rotational spectra obtained with a chirp Fourier transform microwave (FTMW) spectrometer, reveal that the insertion conformations are the most favourable ones in the binary and ternary solvated complexes. In the insertion conformations, the water molecule(s) inserts itself (themselves) into the existing intramolecular hydrogen-bonded ring formed between the alcoholic hydroxyl group and the oxygen of the carbonyl group of ML. The final frequency measurements have been carried out using a cavity based FTMW instrument where internal rotation splittings due to the ester methyl group have also been detected. A number of insertion conformers with subtle structural differences for both the binary and ternary complexes have been identified theoretically. The interconversion dynamics of these conformers and the identification of the most favorable conformers will be discussed. 1. C. Merten, Y. Xu, Angew. Chem. Int. Ed., 2013, 52, 2073 -2076. 2. M. Losada, Y. Xu, Phys. Chem. Chem. Phys., 2007, 9, 3127-3135; Y. Liu, G. Yang, M. Losada, Y. Xu, J. Chem. Phys., 2010, 132, 234513/1-11. 3. A. Zehnacker, M. Suhm, Angew. Chem. Int. Ed. 2008, 47, 6970 - 6992.

  5. Improving the performance and emission characteristics of a single cylinder diesel engine having reentrant combustion chamber using diesel and Jatropha methyl esters.

    PubMed

    Premnath, S; Devaradjane, G

    2015-11-01

    The emissions from the Compression ignition (CI) engines introduce toxicity to the atmosphere. The undesirable carbon deposits from these engines are realized in the nearby static or dynamic systems such as vehicles, inhabitants, etc. The objective of this research work is to improve the performance and emission characteristics of a diesel engine in the modified re-entrant combustion chamber using a diesel and Jatropha methyl ester blend (J20) at three different injection pressures. From the literature, it is revealed that the shape of the combustion chamber and the fuel injection pressure have an impact on the performance and emission parameters of the CI engine. In this work, a re-entrant combustion chamber with three different fuel injection pressures (200, 220 and 240bars) has been used in the place of the conventional hemispherical combustion chamber for diesel and J20. From the experimental results, it is found that the re-entrant chamber improves the brake thermal efficiency of diesel and J20 in all the tested conditions. It is also found that the 20% blend of Jatropha methyl ester showed 4% improvement in the brake thermal efficiency in the re-entrant chamber at the maximum injection pressure. Environmental safety directly relates to the reduction in the undesirable effects on both living and non-living things. Currently environmental pollution is of major concern. Even with the stringent emission norms new methods are required to reduce the harmful effects from automobiles. The toxicity of carbon monoxide (CO) is well known. In the re-entrant combustion chamber, the amount of CO emission is reduced by 26% when compared with the conventional fuel operation of the engine. Moreover, the amount of smoke is reduced by 24% and hydrocarbons (HC) emission by 24%. Thus, the modified re-entrant combustion chamber reduces harmful pollutants such as unburned HC and CO as well as toxic smoke emissions. PMID:26256249

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  7. (7-Diethylaminocoumarin-4-yl)methyl ester of suberoylanilide hydroxamic acid as a caged inhibitor for photocontrol of histone deacetylase activity.

    PubMed

    Ieda, Naoya; Yamada, Sota; Kawaguchi, Mitsuyasu; Miyata, Naoki; Nakagawa, Hidehiko

    2016-06-15

    Histone deacetylases (HDACs) are involved in epigenetic control of the expression of various genes by catalyzing deacetylation of ε-acetylated lysine residues. Here, we report the design, synthesis and evaluation of the (7-diethylaminocoumarin-4-yl)methyl ester of suberoylanilide hydroxamic acid (AC-SAHA) as a caged HDAC inhibitor, which releases the known pan-HDAC inhibitor SAHA upon cleavage of the photolabile (7-diethylaminocoumarin-4-yl)methyl protecting group in response to photoirradiation. A key advantage of AC-SAHA is that the caged derivative itself shows essentially no HDAC-inhibitory activity. Upon photoirradiation, AC-SAHA decomposes to SAHA and a 7-diethylaminocoumarin derivative, together with some minor products. We confirmed that AC-SAHA inhibits HDAC in response to photoirradiation in vitro by means of chemiluminescence assay. AC-SAHA also showed photoinduced inhibition of proliferation of human colon cancer cell line HCT116, as determined by MTT assay. Thus, AC-SAHA should be a useful tool for spatiotemporally controlled inhibition of HDAC activity, as well as a candidate chemotherapeutic reagent for human colon cancer. PMID:27143132

  8. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) The acrylate ester copolymer is a fully polymerized copolymer of ethyl acrylate, methyl methacrylate... emulsion defoamer. Disodium hydrogen phosphate Do. Formaldehyde Glyceryl monostearate Methyl...

  9. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) The acrylate ester copolymer is a fully polymerized copolymer of ethyl acrylate, methyl methacrylate... emulsion defoamer. Disodium hydrogen phosphate Do. Formaldehyde Glyceryl monostearate Methyl...

  10. Carlactone is converted to carlactonoic acid by MAX1 in Arabidopsis and its methyl ester can directly interact with AtD14 in vitro

    PubMed Central

    Abe, Satoko; Sado, Aika; Tanaka, Kai; Kisugi, Takaya; Asami, Kei; Ota, Saeko; Kim, Hyun Il; Yoneyama, Kaori; Xie, Xiaonan; Ohnishi, Toshiyuki; Seto, Yoshiya; Yamaguchi, Shinjiro; Akiyama, Kohki; Yoneyama, Koichi; Nomura, Takahito

    2014-01-01

    Strigolactones (SLs) stimulate seed germination of root parasitic plants and induce hyphal branching of arbuscular mycorrhizal fungi in the rhizosphere. In addition, they have been classified as a new group of plant hormones essential for shoot branching inhibition. It has been demonstrated thus far that SLs are derived from carotenoid via a biosynthetic precursor carlactone (CL), which is produced by sequential reactions of DWARF27 (D27) enzyme and two carotenoid cleavage dioxygenases CCD7 and CCD8. We previously found an extreme accumulation of CL in the more axillary growth1 (max1) mutant of Arabidopsis, which exhibits increased lateral inflorescences due to SL deficiency, indicating that CL is a probable substrate for MAX1 (CYP711A1), a cytochrome P450 monooxygenase. To elucidate the enzymatic function of MAX1 in SL biosynthesis, we incubated CL with a recombinant MAX1 protein expressed in yeast microsomes. MAX1 catalyzed consecutive oxidations at C-19 of CL to convert the C-19 methyl group into carboxylic acid, 9-desmethyl-9-carboxy-CL [designated as carlactonoic acid (CLA)]. We also identified endogenous CLA and its methyl ester [methyl carlactonoate (MeCLA)] in Arabidopsis plants using LC-MS/MS. Although an exogenous application of either CLA or MeCLA suppressed the growth of lateral inflorescences of the max1 mutant, MeCLA, but not CLA, interacted with Arabidopsis thaliana DWARF14 (AtD14) protein, a putative SL receptor, as shown by differential scanning fluorimetry and hydrolysis activity tests. These results indicate that not only known SLs but also MeCLA are biologically active in inhibiting shoot branching in Arabidopsis. PMID:25425668

  11. Probing the Active Center of Benzaldehyde Lyase with Substitutions and the Pseudosubstrate Analogue Benzoylphosphonic Acid Methyl Ester

    SciTech Connect

    Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit; McLeish, Michael J.; Yep, Alejandra; Kenyon, George L.; Petsko, Gregory A.; Jordan, Frank; Ringe, Dagmar

    2008-07-28

    Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg{sup 2+} as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these types of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analogue of benzoylformic acid, is used to probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 {angstrom} (Protein Data Bank entry 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase.

  12. Rosmarinic Acid and Its Methyl Ester as Antimicrobial Components of the Hydromethanolic Extract of Hyptis atrorubens Poit. (Lamiaceae).

    PubMed

    Abedini, Amin; Roumy, Vincent; Mahieux, Séverine; Biabiany, Murielle; Standaert-Vitse, Annie; Rivière, Céline; Sahpaz, Sevser; Bailleul, François; Neut, Christel; Hennebelle, Thierry

    2013-01-01

    Primary biological examination of four extracts of the leaves and stems of Hyptis atrorubens Poit. (Lamiaceae), a plant species used as an antimicrobial agent in Guadeloupe, allowed us to select the hydromethanolic extract of the stems for further studies. It was tested against 46 microorganisms in vitro. It was active against 29 microorganisms. The best antibacterial activity was found against bacteria, mostly Gram-positive ones. Bioautography enabled the isolation and identification of four antibacterial compounds from this plant: rosmarinic acid, methyl rosmarinate, isoquercetin, and hyperoside. The MIC and MBC values of these compounds and their combinations were determined against eight pathogenic bacteria. The best inhibitory and bactericidal activity was found for methyl rosmarinate (0.3 mg/mL). Nevertheless, the bactericidal power of rosmarinic acid was much faster in the time kill study. Synergistic effects were found when combining the active compounds. Finally, the inhibitory effects of the compounds were evaluated on the bacterial growth phases at two different temperatures. Our study demonstrated for the first time antimicrobial activity of Hyptis atrorubens with identification of the active compounds. It supports its traditional use in French West Indies. Although its active compounds need to be further evaluated in vivo, this work emphasizes plants as potent sources of new antimicrobial agents when resistance to antibiotics increases dramatically. PMID:24348709

  13. Rosmarinic Acid and Its Methyl Ester as Antimicrobial Components of the Hydromethanolic Extract of Hyptis atrorubens Poit. (Lamiaceae)

    PubMed Central

    Abedini, Amin; Roumy, Vincent; Mahieux, Séverine; Biabiany, Murielle; Standaert-Vitse, Annie; Rivière, Céline; Sahpaz, Sevser; Bailleul, François

    2013-01-01

    Primary biological examination of four extracts of the leaves and stems of Hyptis atrorubens Poit. (Lamiaceae), a plant species used as an antimicrobial agent in Guadeloupe, allowed us to select the hydromethanolic extract of the stems for further studies. It was tested against 46 microorganisms in vitro. It was active against 29 microorganisms. The best antibacterial activity was found against bacteria, mostly Gram-positive ones. Bioautography enabled the isolation and identification of four antibacterial compounds from this plant: rosmarinic acid, methyl rosmarinate, isoquercetin, and hyperoside. The MIC and MBC values of these compounds and their combinations were determined against eight pathogenic bacteria. The best inhibitory and bactericidal activity was found for methyl rosmarinate (0.3 mg/mL). Nevertheless, the bactericidal power of rosmarinic acid was much faster in the time kill study. Synergistic effects were found when combining the active compounds. Finally, the inhibitory effects of the compounds were evaluated on the bacterial growth phases at two different temperatures. Our study demonstrated for the first time antimicrobial activity of Hyptis atrorubens with identification of the active compounds. It supports its traditional use in French West Indies. Although its active compounds need to be further evaluated in vivo, this work emphasizes plants as potent sources of new antimicrobial agents when resistance to antibiotics increases dramatically. PMID:24348709

  14. Probing the active center of benzaldehyde lyase with substitutions and the pseudo-substrate analog benzoylphosphonic acid methyl ester

    PubMed Central

    Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit; McLeish, Michael J.; Yep, Alejandra; Kenyon, George L.; Petsko, Gregory A.; Jordan, Frank; Ringe, Dagmar

    2009-01-01

    Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg2+ as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these type of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analog of benzoylformic acid, is used to probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 Å (PDB ID: 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase. PMID:18570438

  15. Amidation inhibitors 4-phenyl-3-butenoic acid and 5-(acetylamino)-4-oxo-6-phenyl-2-hexenoic acid methyl ester are novel HDAC inhibitors with anti-tumorigenic properties.

    PubMed

    Ali, Amna; Burns, Timothy J; Lucrezi, Jacob D; May, Sheldon W; Green, George R; Matesic, Diane F

    2015-08-01

    4-Phenyl-3-butenoic acid (PBA) is an inhibitor of peptidylglycine alpha-amidating monooxygenase with anti-inflammatory properties that has been shown to inhibit the growth of ras-mutated epithelial and human lung carcinoma cells. In this report, we show that PBA also increases the acetylation levels of selected histone subtypes in a dose and time dependent manner, an effect that is attributable to the inhibition of histone deacetylase (HDAC) enzymes. Comparison studies with the known HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) using high resolution two-dimensional polyacrylamide gels and Western analysis provide evidence that PBA acts as an HDAC inhibitor within cells. PBA and a more potent amidation inhibitor, 5-(acetylamino)-4-oxo-6-phenyl-2-hexenoic acid methyl ester (AOPHA-Me), inhibit HDAC enzymes in vitro at micromolar concentrations, with IC50 values approximately 30 fold lower for AOPHA-Me than PBA for selected HDAC isoforms. Overall, these results indicate that PBA and AOPHA-Me are novel anti-tumorigenic HDAC inhibitors. PMID:26065689

  16. Ultraviolet photoelectron spectroscopy and inverse photoemission spectroscopy of [6,6]-phenyl-C{sub 61}-butyric acid methyl ester in gas and solid phases

    SciTech Connect

    Akaike, Kouki; Nishi, Toshio; Ouchi, Yukio; Seki, Kazuhiko; Kanai, Kaname; Yoshida, Hiroyuki; Tsutsumi, Jun'ya; Sato, Naoki

    2008-07-15

    The electronic structure of [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) was studied using ultraviolet photoelectron spectroscopy of vapor and thin film and inverse photoemission spectroscopy of thin film. The threshold ionization energy of PCBM was found to be 7.17{+-}0.04 eV in gas phase and 5.96{+-}0.02 eV in solid phase. The threshold electron affinity was 3.9{+-}0.1 eV in solid phase. These values are 0.4-0.6 eV smaller than C{sub 60}. The density functional theory calculations gave consistent results with these trends and suggested that the electron donation from the side chain to C{sub 60} backbone raised the C{sub 60}-backbone-derived {pi} orbitals of PCBM. The polarization energy of PCBM is 1.21 eV, which is almost the same as C{sub 60} but is about 0.5 eV smaller than the value of typical aromatic hydrocarbons.

  17. Isolation and screening of heterocystous cyanobacterial strains for biodiesel production by evaluating the fuel properties from fatty acid methyl ester (FAME) profiles.

    PubMed

    Anahas, Antonyraj Matharasi Perianaika; Muralitharan, Gangatharan

    2015-05-01

    This study reports on the biodiesel quality parameters of eleven heterocystous cyanobacterial strains based on fatty acid methyl esters (FAME) profiles. The biomass productivity of the tested cyanobacterial strains ranged from 9.33 to 20.67 mg L(-1) d(-1) while the lipid productivity varied between 0.65 and 2.358 mg L(-1) d(-1). The highest biomass and lipid productivity was observed for Calothrix sp. MBDU 013 but its lipid content is only 11.221 in terms of percent dry weight, next to the Anabaena sphaerica MBDU 105, whose lipid content is high. To identify the most competent isolate, a multi-criteria decision analyses (MCDA) was performed by including the key chemical and physical parameters of biodiesel calculated from FAME profiles. The isolate A.sphaerica MBDU 105 is the most promising biodiesel feed stock based on decision vector through Preference Ranking Organisation Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA) analysis. PMID:25435067

  18. Effects of nitric oxide synthase inhibitor ω-Nitro-L-Arginine Methyl Ester, on silica-induced inflammatory reaction and apoptosis

    PubMed Central

    Wang, He; Leigh, James

    2006-01-01

    Background Although nitric oxide is overproduced by macrophages and neutrophils after exposure to silica, its role in silica-induced inflammatory reaction and apoptosis needs further clarification. In this study, rats were intratracheally instilled with either silica suspension or saline to examine inflammatory reactions and intraperitoneally injected with ω-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthases, or saline to examine the possible role of nitric oxide production in the reaction. Results Results showed that silica instillation induced a strong inflammatory reaction indicated by increased total cell number, number of neutrophils, protein concentration and lactate dehydrogenase (LDH) activity in bronchoalveolar lavage fluid (BALF). There were no significant differences in these indices between silica-instilled groups with and without L-NAME injection (p > 0.05) except LDH level. The results also showed that apoptotic leucocytes were identified in BALF cells of silica-instilled groups whereas no significant difference was found between silica-instilled groups with and without L-NAME injection in the apoptotic reaction (p > 0.05). Silica instillation significantly increased the level of BALF nitrite/nitrate and L-NAME injection reduced this increase. Conclusion Intratracheal instillation of silica caused an obvious inflammatory reaction and leucocyte apoptosis, but these reactions were not influenced by intraperitoneal injection of L-NAME and reduced production of NO. This supports the possibility that silica-induced lung inflammation and BALF cell apoptosis are via NO-independent mechanisms. PMID:17090306

  19. Evaluation of antifungal activity of free fatty acids methyl esters fraction isolated from Algerian Linum usitatissimum L. seeds against toxigenic Aspergillus

    PubMed Central

    Abdelillah, Amrouche; Houcine, Benmehdi; Halima, Dalile; Meriem, Chabane sari; Imane, Zaaboub; Eddine, Smahi Djamal; Abdallah, Moussaoui; Daoudi, Chabane sari

    2013-01-01

    Objective The aim of this study was to evaluate the antifungal activity of the major fraction of fatty acids methyl esters (FAMEs) isolated from Linum usitatissimum L. seeds oil collected from Bechar department (Algeria). Methods The assessment of antifungal activity was carried out in terms of percentage of radial growth on solid medium (potatoes dextrose agar PDA) and biomass growth inhibition on liquid medium (potatoes dextrose broth PDB) against two fungi. Results The FAMEs was found to be effective in inhibiting the radial mycelial growth of Aspergillus flavus more than Aspergillus ochraceus on all tested concentrations. The highest antifungal index was found to be (54.19%) compared to Aspergillus ochraceus (40.48%). The results of the antifungal activity of the FAMEs inhibition of biomass on liquid medium gave no discounted results, but this does not exclude the antifungal activity. Conclusions We can assume that the observed antifungal potency may be due to the abundance of linoleic and α-linolenic acids in linseed oil which appears to be promising to treat fungal infections, storage fungi and food spoilage in food industry field. PMID:23730556

  20. Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

    SciTech Connect

    Lee, Kyung-Mi; Yun, Ji Ho; Lee, Dong Hwa; Park, Young Gyun; Son, Kun Ho; Nho, Chu Won; Kim, Yeong Shik

    2015-04-17

    We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus.

  1. Structural characterization of gas-phase cysteine and cysteine methyl ester complexes with zinc and cadmium dications by infrared multiple photon dissociation spectroscopy.

    PubMed

    Coates, Rebecca A; McNary, Christopher P; Boles, Georgia C; Berden, Giel; Oomens, Jos; Armentrout, P B

    2015-10-21

    Structural characterization of gas-phase ions of cysteine (Cys) and cysteine methyl ester (CysOMe) complexed to zinc and cadmium is investigated by infrared multiple photon dissociation (IRMPD) action spectroscopy using a free electron laser in combination with density functional theory calculations. IRMPD spectra are measured for [Zn(Cys-H)](+), [Cd(Cys-H)](+), [Zn(CysOMe-H)](+), [Cd(CysOMe-H)](+) and CdCl(+)(CysOMe) and are accompanied by quantum mechanical calculations of the predicted linear absorption spectra at the B3LYP/6-311+G(d,p) (Zn(2+) complexes) and B3LYP/def2TZVP levels (Cd(2+) complexes). On the basis of these experiments and calculations, the conformation that best reproduces the IRMPD spectra for the complexes of the deprotonated amino acids, [M(Cys-H)](+) and [M(CysOMe-H)](+), is a charge-solvated (CS) tridentate structure where the metal dication binds to the amine and carbonyl groups of the amino acid backbone and the deprotonated sulfur atom of the side chain, [N,CO,S(-)]. The intact amino acid complex, CdCl(+)(CysOMe) binds in the equivalent motif [N,CO,S]. These binding motifs are in agreement with the predicted ground structures of these complexes at the B3LYP, B3LYP-GD3BJ (with empirical dispersion corrections), B3P86, and MP2(full) levels. PMID:25880327

  2. On the inapplicability of electron-hopping models for the organic semiconductor Phenyl-C61-butyric Acid Methyl Ester (PCBM)

    SciTech Connect

    Gajdos, Fruzsina; Oberhofer, Harald; Dupuis, Michel; Blumberger, Jochen

    2013-03-21

    Phenyl-C61-butyric Acid Methyl Ester (PCBM) is one of the most popular semiconductors in organic photovoltaic cells, but the electron transport mechanism in the microcrystalline domains of this material as well as its preferred packing structure remains unclear. Here we use density functional theory to calculate electronic coupling matrix elements, reorganization energies and activation energies for available experimental and model crystal structures. We find that the picture of an excess electron hopping from one fullerene to another does not apply for any of the crystalline phases, rendering traditional rate equations inappropriate. We also find that the cohesive energy increases in the order body-centred-cubic < hexagonal < simple cubic < monoclinic < triclinic, independently on the type of dispersion correction used. Our results indicate that the electron-ion dynamics needs to be solved explicitly in order to obtain a realistic description of charge transfer in this material. M.D. was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences and Biosciences. PNNL is a multiprogram national laboratory operated for DOE by Battelle.

  3. Determination of NG-nitro-L-arginine and NG-nitro-L-arginine methyl ester in plasma by high-performance liquid chromatography.

    PubMed

    Whiting, M J; Rutten, A J; Williams, P; Bersten, A D

    1994-10-01

    An HPLC method has been developed for the measurement of the nitric oxide synthase inhibitors, NG-nitro-L-arginine (L-NOLA) and NG-nitro-L-arginine methyl ester (L-NAME), in sheep plasma. Using an ion-exchange HPLC column (JWAS 150, 100 x 3.9 mm I.D., Millipore-Waters, Australia) and post-column ninhydrin detection, L-NOLA was separated from valine and other plasma amino acids. When added to sheep plasma, good recovery (mean 102%) and precision (mean coefficient of variation 2.7%) in the measurement of L-NOLA was obtained over the range 2-50 mg/l. L-NAME was unstable in sheep plasma at 37 degrees C, and was converted to L-NOLA with a half-life of 250 min. This method will permit pharmacokinetic parameters to be determined for these potential drugs, and will allow plasma drug concentrations to be correlated with the pharmacodynamic effects of these compounds. PMID:7858710

  4. Structural, vibrational spectroscopic studies and quantum chemical calculations of n-(2,4-dinitrophenyl)-L-alanine methyl ester by density functional theory

    NASA Astrophysics Data System (ADS)

    Govindarasu, K.; Kavitha, E.

    2015-05-01

    In this paper, the vibrational wavenumbers of N-(2,4-dinitrophenyl)-L-alanine methyl ester (abbreviated as Dnp-ala-ome) were obtained from ab initio studies based on the density functional theory approach with B3LYP and M06-2X/6-31G(d,p) level of theories. The optimized geometry and structural features of the most potential nonlinear optical crystal Dnp-ala-ome and the vibrational spectral investigations have been thoroughly described with the FT-Raman and FT-IR spectra supported by the DFT computations. FT-IR (4000-400 cm-1) and FT-Raman spectra (3500-50 cm-1) in the solid phase and the UV-Vis spectra that dissolved in ethanol were recorded in the range of 200-800 nm. The Natural population analysis and natural bond orbital (NBO) analysis have also been carried out to analyze the effects of intramolecular charge transfer, intramolecular and hyperconjugative interactions on the geometries. The effects of frontier orbitals, HOMO and LUMO, transition of electron density transfer have also been discussed. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of Dnp-ala-ome were calculated. In addition, molecular electrostatic potential (MEP) was investigated using theoretical calculations. The chemical reactivity and thermodynamic properties (heat capacity, entropy and enthalpy) of at different temperature are calculated.

  5. Experimental designs for modeling retention patterns and separation efficiency in analysis of fatty acid methyl esters by gas chromatography-mass spectrometry.

    PubMed

    Skartland, Liv Kjersti; Mjøs, Svein A; Grung, Bjørn

    2011-09-23

    The retention behavior of components analyzed by chromatography varies with instrumental settings. Being able to predict how changes in these settings alter the elution pattern is useful, both with regards to component identification, as well as with regards to optimization of the chromatographic system. In this work, it is shown how experimental designs can be used for this purpose. Different experimental designs for response surface modeling of the separation of fatty acid methyl esters (FAME) as function of chromatographic conditions in GC have been evaluated. Full factorial, central composite, Doehlert and Box-Behnken designs were applied. A mixture of 38 FAMEs was separated on a polar cyanopropyl substituted polysilphenylene-siloxane phase capillary column. The temperature gradient, the start temperature of the gradient, and the carrier gas velocity were varied in the experiments. The modeled responses, as functions of chromatographic conditions, were retention time, retention indices, peak widths, separation efficiency and resolution between selected peak pairs. The designs that allowed inclusion of quadratic terms among the predictors performed significantly better than factorial design. Box-Behnken design provided the best results for prediction of retention, but the differences between the central composite, Doehlert and Box-Behnken designs were small. Retention indices could be modeled with much better accuracy than retention times. However, because the errors of predicted tR of closely eluting peaks were highly correlated, models of resolution (Rs) that were based on retention time had errors in the same range as corresponding models based on ECL. PMID:21851946

  6. FT-IR, FT-Raman, ab initio and DFT structural, vibrational frequency and HOMO-LUMO analysis of 1-naphthaleneacetic acid methyl ester.

    PubMed

    Nagabalasubramanian, P B; Karabacak, Mehmet; Periandy, S

    2011-11-01

    In this work, the FT-IR and FT-Raman spectra of 1-naphthaleneacetic acid methyl ester (abbreviated as 1-NAAME, C(10)H(7)CH(2)CO(2)CH(3)) have been recorded in the region 3600-10 cm(-1). The optimum molecular geometry, normal mode wavenumbers, infrared and Raman intensities, Raman scattering activities, corresponding vibrational assignments, Mullikan atomic charges and other thermo-dynamical parameters were investigated with the help of HF and B3LYP (DFT) method using 6-31G(d,p), 6-311G(d,p) basis sets. Reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated with scaled quantum mechanical (SQM) method. From the calculations, the molecules are predicted to exist predominantly as the C1 conformer. The correlation equations between heat capacity, entropy, enthalpy changes and temperatures were fitted by quadratic formulae. Lower value in the HOMO and LUMO energy gap explains the eventual charge transfer interactions taking place within the molecule. UV-VIS spectral analyses of 1NAAME have been researched by theoretical calculations. In order to understand electronic transitions of the compound, TD-DFT calculations on electronic absorption spectra in gas phase and solvent (DMSO and chloroform) were performed. The calculated frontier orbital energies, absorption wavelengths (λ), oscillator strengths (f) and excitation energies (E) for gas phase and solvent (DMSO and chloroform) are also illustrated. PMID:21820351

  7. FT-IR, FT-Raman, ab initio and DFT structural, vibrational frequency and HOMO-LUMO analysis of 1-naphthaleneacetic acid methyl ester

    NASA Astrophysics Data System (ADS)

    Nagabalasubramanian, P. B.; Karabacak, Mehmet; Periandy, S.

    2011-11-01

    In this work, the FT-IR and FT-Raman spectra of 1-naphthaleneacetic acid methyl ester (abbreviated as 1-NAAME, C 10H 7CH 2CO 2CH 3) have been recorded in the region 3600-10 cm -1. The optimum molecular geometry, normal mode wavenumbers, infrared and Raman intensities, Raman scattering activities, corresponding vibrational assignments, Mullikan atomic charges and other thermo-dynamical parameters were investigated with the help of HF and B3LYP (DFT) method using 6-31G(d,p), 6-311G(d,p) basis sets. Reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated with scaled quantum mechanical (SQM) method. From the calculations, the molecules are predicted to exist predominantly as the C1 conformer. The correlation equations between heat capacity, entropy, enthalpy changes and temperatures were fitted by quadratic formulae. Lower value in the HOMO and LUMO energy gap explains the eventual charge transfer interactions taking place within the molecule. UV-VIS spectral analyses of 1NAAME have been researched by theoretical calculations. In order to understand electronic transitions of the compound, TD-DFT calculations on electronic absorption spectra in gas phase and solvent (DMSO and chloroform) were performed. The calculated frontier orbital energies, absorption wavelengths ( λ), oscillator strengths ( f) and excitation energies ( E) for gas phase and solvent (DMSO and chloroform) are also illustrated.

  8. Mechanisms of some hydrogen-transfer reactions: temperature dependence of the kinetic isotope effect and intramolecular C-H insertion: synthesis of (+/-)-pentalenolactone E methyl ester

    SciTech Connect

    Schuchardt, J.L.

    1985-01-01

    The mechanisms of three familiar organic hydrogen transfer reactions have been investigated by a study of the temperature dependence of the kinetic isotope effect. The Oppenauer oxidation of benzhydrol to benzophenone resulted in relatively small isotope effects (k/sub H//k/sub D/ = 2.3 10/sup 0/C), which are consistent with either a linear, unsymmetrical or a nonlinear H-transfer. The temperature dependence of k/sub H//k/sub D/ is in doubt due to an unanticipated isotopic scrambling effect. The Grignard reduction of benzophenone by isobutylmagnesium bromide shows significant temperature dependence of the kinetic isotope effect. The less-than-maximum isotope effects and activation energy difference suggest an unsymmetrical linear H-transfer mechanism. There is no evidence of tunneling in either the Oppenauer oxidation of the Grignard reduction with the system investigated. The reduction of benzyl bromide by tri-n-butyltin hydride gives temperature-dependent isotope effects and activation parameters consistent with an unsymmetrical linear H-transfer. The results for cyclohexyl bromide were less illuminating. (+/-)-Pentalenolactone E methyl ester was synthesized in 12 steps from 4,4-dimethylcyclohexanone. Disconnection of the target molecule at a unveils substantial molecular symmetry. The key to the analysis is the synthetic step which allows bond formation to an unfunctionalized carbon atom. The key step, rhodium-mediated intramolecular C-H insertion successfully generated the tricyclic skeleton of pentalenolactone via a sterically congested transition state.

  9. Nitro-arginine methyl ester, a non-selective inhibitor of nitric oxide synthase reduces ibuprofen-induced gastric mucosal injury in the rat.

    PubMed

    Abraham, Premila; K, Indirani; K, Desigamani

    2005-09-01

    Ibuprofen is a commonly used non-steroidal anti-inflammatory drug. Gastrointestinal adverse drug reactions from ibuprofen usage include gastric mucosal ulcers and bleeding. The mechanism by which ibuprofen induces gastric mucosal damage is not clear. The present study is an attempt to examine the role of nitric oxide in the pathogenesis of ibuprofen-induced gastric mucosal damage. Ibuprofen administered orally at the dose of 100 mg/kg body weight for 6 days to the rats resulted in gastric mucosal injury. Serum nitrite and nitrosothiol were increased significantly as compared with the controls, which were treated with the vehicle alone. In the gastric mucosa, lipid peroxidation and protein thiols were increased, and the activity of glyceraldehyde 3-phosphate dehydrogenase, a nitric oxide sensitive enzyme was decreased significantly. Pretreatment of the rats daily with nitric oxide synthase inhibitor, nitro-arginine methyl ester (30 mg/kg body weight) 1 hr before treatment with ibuprofen reduced the gastric mucosal injury. Biochemically, it prevented the rise in serum nitrite levels and the increase in lipid peroxidation and protein thiol levels and the loss of glyceraldehyde 3-phosphate dehydrogenase activity in the gastric mucosa. The results of the present study suggest that increased nitric oxide production may be one of the mechanisms by which ibuprofen produces gastric mucosal injury and that inhibition of nitric oxide synthase reduces gastric mucosal injury. PMID:16133962

  10. Prediction of capillary gas chromatographic retention times of fatty acid methyl esters in human blood using MLR, PLS and back-propagation artificial neural networks.

    PubMed

    Gupta, Vinod Kumar; Khani, Hadi; Ahmadi-Roudi, Behzad; Mirakhorli, Shima; Fereyduni, Ehsan; Agarwal, Shilpi

    2011-01-15

    Quantitative structure-retention relationship (QSRR) models correlating the retention times of fatty acid methyl esters in high resolution capillary gas chromatography and their structures were developed based on non-linear and linear modeling methods. Genetic algorithm (GA) was used for the selection of the variables that resulted in the best-fitted models. Gravitational index (G2), number of cis double bond (NcDB) and number of trans double bond (NtDB) were selected among a large number of descriptors. The selected descriptors were considered as inputs for artificial neural networks (ANNs) with three different weights update functions including Levenberg-Marquardt backpropagation network (LM-ANN), BFGS (Broyden, Fletcher, Goldfarb, and Shanno) quasi-Newton backpropagation (BFG-ANN) and conjugate gradient backpropagation with Polak-Ribiére updates (CGP-ANN). Computational result indicates that the LM-ANN method has better predictive power than the other methods. The model was also tested successfully for external validation criteria. Standard error for the training set using LM-ANN was SE=0.932 with correlation coefficient R=0.996. For the prediction and validation sets, standard error was SE=0.645 and SE=0.445 and correlation coefficient was R=0.999 and R=0.999, respectively. The accuracy of 3-2-1 LM-ANN model was illustrated using leave multiple out-cross validations (LMO-CVs) and Y-randomization. PMID:21147352

  11. Synthesis of structured lipids by lipase-catalyzed interesterification of triacetin with camellia oil methyl esters and preliminary evaluation of their plasma lipid-lowering effect in mice.

    PubMed

    Cao, Yu; Qi, Suijian; Zhang, Yang; Wang, Xiaoning; Yang, Bo; Wang, Yonghua

    2013-01-01

    Structured lipids (SLCTs triacylglycerols with short- and long-chain acyl residues) were synthesized by interesterification of triacetin and fatty acid methyl esters (FAMEs) from camellia oil, followed by molecular distillation for purification. Different commercial immobilized lipases (Lipozyme RM IM and Novozyme 435), the substrate molar ratios of FAMEs to triacetin, the reaction temperatures and the lipase amounts were studied for their efficiency in producing SLCTs. Results showed that Novozyme 435 was more suitable for this reaction system. Moreover, the optimal reaction conditions for the highest conversion of FAMEs and the highest LLS-TAGs (triacylglycerols with one short- and two long-chain acyl residues) yields were achieved at a molar ratio of FAMEs to triacetin of 3:1, 50 °C of reaction temperature and a lipase amount of 4% (w/v). Scale-up was conducted based on the optimized reaction conditions. Results showed that after 24 h of reaction , the conversion rate of FAMEs was 82.4% and the rate of disubstituted triacetin was 52.4 mol%. The final product yield rate was 94.6%. The effects of the synthesized SLCTs on the plasma lipid level of fasting mice were also studied. The SLCTs could effectively lessen the total triacylglycerol levels in plasma compared to the triacylglycerol group in fasting NIH mice. It suggested that this type of structured lipid might be beneficial for human health, especially for the prevention of obesity. PMID:23529033

  12. L-leucyl-l-leucine methyl ester treatment of canine marrow and peripheral blood cells: Inhibition of proliferative responses with maintenance of the capacity for autologous marrow engraftment

    SciTech Connect

    Raff, R.F.; Severns, E.; Storb, R.; Martin, P.; Graham, T.

    1988-11-01

    The success of allogeneic marrow transplantation as treatment for malignant and nonmalignant hematopoietic diseases has been restricted by the serious complications of graft-versus-host disease. Experiments in a variety of mammalian marrow transplant models have shown that removal of mature T cells from donor marrow permits engraftment without the development of GVHD. Incubation of canine marrow and peripheral blood mononuclear cells with L-leucyl-L-leucine methyl ester resulted in the inhibition of mitogen-and alloantigen induced blastogenesis, the elimination of allosensitized Cytotoxic T Lymphocyte and Natural Killer activity, and prevented the development of CTL from pCTL. The effects of these incubations were similar to those described in mice and humans. Additionally, in vitro CFU-GM growth from treated canine marrow was reduced, but could be regained when the Leu-Leu-OMe-treated marrow was cocultured with either untreated autologous peripheral blood mononuclear cells or monocyte-enriched PBMC but not with untreated monocyte-depleted PBMC. Six of seven dogs conditioned with 920 cGy total-body irradiation engrafted successfully after receiving autologous marrow that was incubated with Leu-Leu-OMe prior to infusion. These cumulative results indicate that incubation with Leu-Leu-OMe is a feasible method to deplete canine marrows of alloreactive and cytotoxic T cells prior to transplantation.

  13. Ultrasound assisted production of fatty acid methyl esters from transesterification of triglycerides with methanol in the presence of KOH catalyst: optimization, mechanism and kinetics.

    PubMed

    Thanh, Le Tu; Okitsu, Kenji; Maeda, Yasuaki; Bandow, Hiroshi

    2014-03-01

    Ultrasound assisted transesterification of triglycerides (TG) with methanol in the presence of KOH catalyst was investigated, where the changes in the reactants and products (diglycerides (DG), monoglycerides (MG), fatty acid methyl esters (FAME) and glycerin (GL)) concentrations were discussed to understand the reaction mechanism and kinetics under ultrasound irradiation. The optimum reaction condition for the FAME production was the concentration of KOH 1.0 wt.%, molar ratio of TG to methanol of 1:6, and irradiation time of 25 min. The rate constants during the TG transesterification with methanol into GL and FAME were estimated by a curve fitting method with simulated curves to the obtained experimental results. The rate constants of [Formula: see text] were estimated to be 0.21, 0.008, 0.23, 0.005, 0.14 and 0.001 L mol(-1)min(-1), respectively. The rate determining step for the TG transesterification with methanol into GL and FAME was the reaction of MG with methanol into GL and FAME. PMID:24161255

  14. Pharmacokinetics evaluation of 132-hydroxy-bacteriopheophorbid-a methyl ester and octa-alpha-butyloxy-zinc phthalocyanine for future application in PDT

    NASA Astrophysics Data System (ADS)

    Ismail, M. Samy; Dressler, Cathrin; Roeder, Beate; Weitzel, H.; Berlien, Hans-Peter

    1997-12-01

    The pharmacokinetics of 132-hydroxy-bacteriopheophorbid-a methyl ester (132-OH-BPME) and octa-(alpha) -butyloxy-zinc phthalocyanine (8-(alpha) -bo-Zn-Pc) were studied in mice bearing Lewis lung carcinoma. Absorption spectroscopy was used to measure the photosensitizers concentrations. High 132- OH-BPME and 8-(alpha) -bo-Zn-Pc uptakes were recorded in the parenchymatous organs (liver, lung), with 8-(alpha) -bo-Zn-Pc long retention. The malignant tissues accumulated 132-OH- BPME of more than 20 folds than 8-(alpha) -bo-Zn-Pc at all incubation times. 8-(alpha) -bo-Zn-Pc concentrations in the skin and the muscle were lower than 132-OH-BPME concentrations at any interval period, but also, the 8- (alpha) -bo-Zn-Pc retained longer until 168 h. PDT with 132-OH-BPME will be more effective than with 8-(alpha) -bo- Zn-Pc where it has more concentrations in the malignant tissues.

  15. A case study on quantitative in vitro to in vivo extrapolation for environmental esters: Methyl-, propyl- and butylparaben.

    PubMed

    Campbell, Jerry L; Yoon, Miyoung; Clewell, Harvey J

    2015-06-01

    Parabens have been reported as potential endocrine disrupters and are widely used in consumer projects including cosmetics, foods and pharmaceuticals. We report on the development of a PBPK model for methyl-, propyl-, and butylparaben. The model was parameterized through a combination of QSAR for tissue solubility and quantitative in vitro to in vivo extrapolation (IVIVE) for hydrolysis in portals of entry including intestine and skin as well as in the primary site of metabolism, the liver. Overall, the model provided very good agreement with published time-course data in blood and urine from controlled dosing studies in rat and human, and demonstrates the potential value of quantitative IVIVE in expanding the use of human biomonitoring data in safety assessment. An in vitro based cumulative margin of safety (MOS) was calculated by comparing the effective concentrations from an in vitro assay of estrogenicity to the free paraben concentrations predicted by the model to be associated with the 95th percentile urine concentrations reported in NHANES (2009-2010 collection period). The calculated MOS for adult females was 108, whereas the MOS for males was 444. PMID:25839974

  16. An analytical method for trifluoroacetic Acid in water and air samples using headspace gas chromatographic determination of the methyl ester.

    PubMed

    Zehavi, D; Seiber, J N

    1996-10-01

    An analytical method has been developed for the determination of trace levels of trifluoroacetic acid (TFA), an atmospheric breakdown product of several of the hydrofluorocarbon (HFC) and hydrochlorofluorocarbon (HCFC) replacements for the chlorofluorocarbon (CFC) refrigerants, in water and air. TFA is derivatized to the volatile methyl trifluoroacetate (MTFA) and determined by automated headspace gas chromatography (HSGC) with electron-capture detection or manual HSGC using GC/MS in the selected ion monitoring (SIM) mode. The method is based on the reaction of an aqueous sample containing TFA with dimethyl sulfate (DMS) in concentrated sulfuric acid in a sealed headspace vial under conditions favoring distribution of MTFA to the vapor phase. Water samples are prepared by evaporative concentration, during which TFA is retained as the anion, followed by extraction with diethyl ether of the acidified sample and then back-extraction of TFA (as the anion) in aqueous bicarbonate solution. The extraction step is required for samples with a relatively high background of other salts and organic materials. Air samples are collected in sodium bicarbonate-glycerin-coated glass denuder tubes and prepared by rinsing the denuder contents with water to form an aqueous sample for derivatization and analysis. Recoveries of TFA from spiked water, with and without evaporative concentration, and from spiked air were quantitative, with estimated detection limits of 10 ng/mL (unconcentrated) and 25 pg/mL (concentrated 250 mL:1 mL) for water and 1 ng/m(3) (72 h at 5 L/min) for air. Several environmental air, fogwater, rainwater, and surface water samples were successfully analyzed; many showed the presence of TFA. PMID:21619278

  17. Therapeutic effects of C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO-Me; bardoxolone methyl) on radiation-induced lung inflammation and fibrosis in mice

    PubMed Central

    Wang, Yan-Yang; Zhang, Cui-Ying; Ma, Ya-Qiong; He, Zhi-Xu; Zhe, Hong; Zhou, Shu-Feng

    2015-01-01

    The C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO-Me), one of the synthetic triterpenoids, has been found to have potent anti-inflammatory and anticancer properties in vitro and in vivo. However, its usefulness in mitigating radiation-induced lung injury (RILI), including radiation-induced lung inflammation and fibrosis, has not been tested. The aim of this study was to explore the therapeutic effect of CDDO-Me on RILI in mice and the underlying mechanisms. Herein, we found that administration of CDDO-Me improved the histopathological score, reduced the number of inflammatory cells and concentrations of total protein in bronchoalveolar lavage fluid, suppressed secretion and expression of proinflammatory cytokines, including transforming growth factor-β and interleukin-6, elevated expression of the anti-inflammatory cytokine interleukin-10, and downregulated the mRNA level of profibrotic genes, including for fibronectin, α-smooth muscle actin, and collagen I. CDDO-Me attenuated radiation-induced lung inflammation. CDDO-Me also decreased the Masson’s trichrome stain score, hydroxyproline content, and mRNA level of profibrotic genes, and blocked radiation-induced collagen accumulation and fibrosis. Collectively, these findings suggest that CDDO-Me ameliorates radiation-induced lung inflammation and fibrosis, and this synthetic triterpenoid is a promising novel therapeutic agent for RILI. Further mechanistic, efficacy, and safety studies are warranted to elucidate the role of CDDO-Me in the management of RILI. PMID:26124639

  18. Biodiesel With Optimized Fatty Ester Composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is largely composed of the mono-alkyl esters, usually methyl esters, of vegetable oils or animal fats with its fatty acid profile corresponding to that of the parent oil or fat. The different fatty esters have varying properties of relevance to biodiesel. The feedstock-dependent variatio...

  19. Comparison of effects of chronic and acute administration of NG-nitro-L-arginine methyl ester to the rat on inhibition of nitric oxide-mediated responses.

    PubMed Central

    Bryant, C E; Allcock, G H; Warner, T D

    1995-01-01

    1. Vascular responses to acetylcholine and sodium nitroprusside in vivo and in vitro, in the isolated perfused kidney and in rings of rat thoracic aorta, were measured in rats treated chronically with NG-nitro-L-arginine methyl ester (L-NAME; approx, 70 mg kg-1) and compared to responses in age-matched control animals, and age-matched animals after the acute administration of L-NAME (3-100 mumol kg-1). Parallel experiments examined alterations in responsiveness in rings of trachea and anococcygeus muscles taken from the same animals. 2. Chronic oral administration of L-NAME elevated the blood pressure in anaesthetized animals from 114 +/- 5 mmHg to 153 +/- 11 mmHg (n = 5). The hypotensive responses to both acetylcholine (1 nmol kg-1) and sodium nitroprusside (10 nmol kg-1) were enhanced by chronic L-NAME treatment (n = 5-7) whereas acute L-NAME administration enhanced only the response to sodium nitroprusside (n = 5). 3. After chronic treatment with L-NAME, the basal perfusion pressure in the isolated perfused kidney was elevated. However, vasodilator responses to either acetylcholine (1 nmol) or sodium nitroprusside (3 nmol) were unaltered (n = 5-7). The vasodilatation induced by acetylcholine was inhibited in a concentration-dependent manner by the administration of acute L-NAME (0.1 - 100 microM; n = 5), such that significant inhibition was seen at 10 microM L-NAME. The response to sodium nitroprusside was unaffected by L-NAME.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 Figure 3 PMID:7541283

  20. Chronic N(G)-nitro-L-arginine methyl ester-induced hypertension : novel molecular adaptation to systolic load in absence of hypertrophy

    NASA Technical Reports Server (NTRS)

    Bartunek, J.; Weinberg, E. O.; Tajima, M.; Rohrbach, S.; Katz, S. E.; Douglas, P. S.; Lorell, B. H.; Schneider, M. (Principal Investigator)

    2000-01-01

    BACKGROUND: Chronic N(G)-nitro-L-arginine methyl ester (L-NAME), which inhibits nitric oxide synthesis, causes hypertension and would therefore be expected to induce robust cardiac hypertrophy. However, L-NAME has negative metabolic effects on protein synthesis that suppress the increase in left ventricular (LV) mass in response to sustained pressure overload. In the present study, we used L-NAME-induced hypertension to test the hypothesis that adaptation to pressure overload occurs even when hypertrophy is suppressed. METHODS AND RESULTS: Male rats received L-NAME (50 mg. kg(-1). d(-1)) or no drug for 6 weeks. Rats with L-NAME-induced hypertension had levels of systolic wall stress similar to those of rats with aortic stenosis (85+/-19 versus 92+/-16 kdyne/cm). Rats with aortic stenosis developed a nearly 2-fold increase in LV mass compared with controls. In contrast, in the L-NAME rats, no increase in LV mass (1. 00+/-0.03 versus 1.04+/-0.04 g) or hypertrophy of isolated myocytes occurred (3586+/-129 versus 3756+/-135 microm(2)) compared with controls. Nevertheless, chronic pressure overload was not accompanied by the development of heart failure. LV systolic performance was maintained by mechanisms of concentric remodeling (decrease of in vivo LV chamber dimension relative to wall thickness) and augmented myocardial calcium-dependent contractile reserve associated with preserved expression of alpha- and beta-myosin heavy chain isoforms and sarcoplasmic reticulum Ca(2+) ATPase (SERCA-2). CONCLUSIONS: When the expected compensatory hypertrophic response is suppressed during L-NAME-induced hypertension, severe chronic pressure overload is associated with a successful adaptation to maintain systolic performance; this adaptation depends on both LV remodeling and enhanced contractility in response to calcium.

  1. Quantum confinement-tunable ultrafast charge transfer at the PbS quantum dot and phenyl-C₆₁-butyric acid methyl ester interface.

    PubMed

    El-Ballouli, Ala'a O; Alarousu, Erkki; Bernardi, Marco; Aly, Shawkat M; Lagrow, Alec P; Bakr, Osman M; Mohammed, Omar F

    2014-05-14

    Quantum dot (QD) solar cells have emerged as promising low-cost alternatives to existing photovoltaic technologies. Here, we investigate charge transfer and separation at PbS QDs and phenyl-C61-butyric acid methyl ester (PCBM) interfaces using a combination of femtosecond broadband transient absorption (TA) spectroscopy and steady-state photoluminescence quenching measurements. We analyzed ultrafast electron injection and charge separation at PbS QD/PCBM interfaces for four different QD sizes and as a function of PCBM concentration. The results reveal that the energy band alignment, tuned by the quantum size effect, is the key element for efficient electron injection and charge separation processes. More specifically, the steady-state and time-resolved data demonstrate that only small-sized PbS QDs with a bandgap larger than 1 eV can transfer electrons to PCBM upon light absorption. We show that these trends result from the formation of a type-II interface band alignment, as a consequence of the size distribution of the QDs. Transient absorption data indicate that electron injection from photoexcited PbS QDs to PCBM occurs within our temporal resolution of 120 fs for QDs with bandgaps that achieve type-II alignment, while virtually all signals observed in smaller bandgap QD samples result from large bandgap outliers in the size distribution. Taken together, our results clearly demonstrate that charge transfer rates at QD interfaces can be tuned by several orders of magnitude by engineering the QD size distribution. The work presented here will advance both the design and the understanding of QD interfaces for solar energy conversion. PMID:24521255

  2. The effects of perfusion rate and NG-nitro-L-arginine methyl ester on cirazoline- and KCl-induced responses in the perfused mesenteric arterial bed of rats.

    PubMed Central

    Adeagbo, A. S.; Tabrizchi, R.; Triggle, C. R.

    1994-01-01

    1. The purpose of this study was to characterize the effect of NG-nitro-L-arginine methyl ester (L-NAME) on the perfusion rate/pressure relations, and on the pressor responses induced to cirazoline and KCl in isolated, perfused mesenteric arterial beds from normotensive and spontaneously hypertensive rats. 2. The basal perfusion pressure of arterial beds perfused with either physiological salt solution (PSS) or PSS containing 1% polyvinylpyrrolidone increased as the perfusion rate increased. L-NAME, in concentrations up to 100 microM, failed to alter the basal pressure regardless of the perfusion rate and viscosity; however, at 5 microM, it potentiated cirazoline-induced vasoconstriction at each of the perfusion rates. 3. L-NAME but not D-NAME caused a leftward shift of cirazoline concentration-response curves with a marked increase in the maximal response. The potentiating action of L-NAME was abolished in arterial beds perfused with a Ca(2+)-free physiological salt solution and also in beds denuded of endothelium by an infusion of distilled water for 5 min. 4. In endothelium-intact and -denuded preparations, L-NAME potentiated KCl pressor responses; the endothelium-independent potentiation of KCl pressor activity was stereospecific, time-independent and was not prevented by the presence of dexamethasone (0.5 microM) in the perfusion medium. However, L-NAME failed to potentiate vasoconstriction obtained to KCl in arterial beds denervated by cold storage (4-5 degrees C) for 2 days. 5. The absence of K+ in the perfusate did not inhibit the ability of L-NAME to potentiate alpha-adrenoceptor-mediated pressor responses, and nor did L-NAME inhibit KCl-induced vasodilatation in preconstricted arteries. It was thus concluded that L-NAME does not affect Na+/K(+)-ATPase activity.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7912152

  3. Neuroprotective Role of L-NG-Nitroarginine Methyl Ester (L-NAME) against Chronic Hypobaric Hypoxia with Crowding Stress (CHC) Induced Depression-Like Behaviour

    PubMed Central

    Deep, Satya Narayan; Baitharu, Iswar; Sharma, Apurva; Gurjar, Anoop Kishor Singh; Prasad, Dipti; Singh, Shashi Bala

    2016-01-01

    Improper neuroimmune responses following chronic stress exposure have been reported to cause neuronal dysfunctions leading to memory impairment, anxiety and depression like behaviours. Though several factors affecting microglial activation and consequent alteration in neuro-inflammatory responses have been well studied, role of NO and its association with microglia in stress induced depression model is yet to be explored. In the present study, we validated combination of chronic hypobaric hypoxia and crowding (CHC) as a stress model for depression and investigated the role of chronic stress induced elevated nitric oxide (NO) level in microglia activation and its effect on neuro-inflammatory responses in brain. Further, we evaluated the ameliorative effect of L-NG-Nitroarginine Methyl Ester (L-NAME) to reverse the stress induced depressive mood state. Four groups of male Sprague Dawley rat were taken and divided into control and CHC stress exposed group with and without treatment of L-NAME. Depression like behaviour and anhedonia in rats were assessed by Forced Swim Test (FST) and Sucrose Preference Test (SPT). Microglial activation was evaluated using Iba-1 immunohistochemistry and proinflammatory cytokines were assessed in the hippocampal region. Our result showed that exposure to CHC stress increased the number of active microglia with corresponding increase in inflammatory cytokines and altered behavioural responses. The inhibition of NO synthesis by L-NAME during CHC exposure decreased the number of active microglia in hippocampus as evident from decreased Iba-1 positive cells. Further, L-NAME administration decreased pro-inflammatory cytokines in hippocampus and improved behaviour of rats. Our study demonstrate that stress induced elevation of NO plays pivotal role in altered microglial activation and consequent neurodegenerative processes leading to depression like behaviour in rat. PMID:27082990

  4. The Nitric Oxide Synthase Inhibitor NG-Nitro-L-Arginine Methyl Ester Diminishes the Immunomodulatory Effects of Parental Arginine in Rats with Subacute Peritonitis.

    PubMed

    Lo, Hui-Chen; Hung, Ching-Yi; Huang, Fu-Huan; Su, Tzu-Cheng; Lee, Chien-Hsing

    2016-01-01

    The combined treatment of parenteral arginine and the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) have been shown to improve liver function and systemic inflammation in subacute peritonitic rats. Here, we investigated the effects of single and combined parenteral arginine and L-NAME treatments on leukocyte and splenocyte immunity. Male Wistar rats were subjected to cecal punctures and were intravenously given total parenteral nutrition solutions with or without arginine and/or L-NAME supplementations for 7 days. Non-surgical and sham-operated rats with no cecal puncture were given a chow diet and parenteral nutrition, respectively. Parenteral feeding elevated the white blood cell numbers and subacute peritonitis augmented the parenteral nutrition-induced alterations in the loss of body weight gain, splenomegaly, and splenocyte decreases. Parenteral arginine significantly increased the B-leukocyte level, decreased the natural killer T (NKT)-leukocyte and splenocyte levels, alleviated the loss in body weight gain and total and cytotoxic T-splenocyte levels, and attenuated the increases in plasma nitrate/nitrite and interferon-gamma production by T-splenocytes. L-NAME infusion significantly decreased NKT-leukocyte level, tumor-necrosis factor (TNF)-alpha production by T-splenocytes and macrophages, and interferon-gamma production by T-leukocytes, monocytes, and T-splenocytes, as well as increased interleukin-6 production by T-leukocytes and monocytes and nitrate/nitrite production by T-leukocytes. Combined treatment significantly decreased plasma nitrate/nitrite, the NKT-leukocyte level, and TNF-alpha production by T-splenocytes. Parenteral arginine may attenuate immune impairment and L-NAME infusion may augment leukocyte proinflammatory response, eliminate splenocyte proinflammatory and T-helper 1 responses, and diminish arginine-induced immunomodulation in combined treatment in subacute peritonitic rats. PMID:27007815

  5. The Nitric Oxide Synthase Inhibitor NG-Nitro-L-Arginine Methyl Ester Diminishes the Immunomodulatory Effects of Parental Arginine in Rats with Subacute Peritonitis

    PubMed Central

    Lo, Hui-Chen; Hung, Ching-Yi; Huang, Fu-Huan; Su, Tzu-Cheng; Lee, Chien-Hsing

    2016-01-01

    The combined treatment of parenteral arginine and the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) have been shown to improve liver function and systemic inflammation in subacute peritonitic rats. Here, we investigated the effects of single and combined parenteral arginine and L-NAME treatments on leukocyte and splenocyte immunity. Male Wistar rats were subjected to cecal punctures and were intravenously given total parenteral nutrition solutions with or without arginine and/or L-NAME supplementations for 7 days. Non-surgical and sham-operated rats with no cecal puncture were given a chow diet and parenteral nutrition, respectively. Parenteral feeding elevated the white blood cell numbers and subacute peritonitis augmented the parenteral nutrition-induced alterations in the loss of body weight gain, splenomegaly, and splenocyte decreases. Parenteral arginine significantly increased the B-leukocyte level, decreased the natural killer T (NKT)-leukocyte and splenocyte levels, alleviated the loss in body weight gain and total and cytotoxic T-splenocyte levels, and attenuated the increases in plasma nitrate/nitrite and interferon-gamma production by T-splenocytes. L-NAME infusion significantly decreased NKT-leukocyte level, tumor-necrosis factor (TNF)-alpha production by T-splenocytes and macrophages, and interferon-gamma production by T-leukocytes, monocytes, and T-splenocytes, as well as increased interleukin-6 production by T-leukocytes and monocytes and nitrate/nitrite production by T-leukocytes. Combined treatment significantly decreased plasma nitrate/nitrite, the NKT-leukocyte level, and TNF-alpha production by T-splenocytes. Parenteral arginine may attenuate immune impairment and L-NAME infusion may augment leukocyte proinflammatory response, eliminate splenocyte proinflammatory and T-helper 1 responses, and diminish arginine-induced immunomodulation in combined treatment in subacute peritonitic rats. PMID:27007815

  6. The Influence of Fatty Acid Methyl Esters (FAMEs) in the Biochemistry and the Na(+)/K(+)-ATPase Activity of Culex quinquefasciatus Larvae.

    PubMed

    Silva, Lilian N D; Ribeiro-Neto, José A; Valadares, Jéssica M M; Costa, Mariana M; Lima, Luciana A R S; Grillo, Luciano A M; Cortes, Vanessa F; Santos, Herica L; Alves, Stênio N; Barbosa, Leandro A

    2016-08-01

    Culex quinquefasciatus is the main vector of lymphatic filariasis and combating this insect is of great importance to public health. There are reports of insects that are resistant to the products currently used to control this vector, and therefore, the search for new products has increased. In the present study, we have evaluated the effects of fatty acid methyl esters (FAMEs) that showed larvicidal activity against C. quinquefasciatus, on glucose, total protein, and triacylglycerol contents and Na(+)/K(+)-ATPase activity in mosquito larvae. The exposure of the fourth instar larvae to the compounds caused a decrease in the total protein content and an increase in the activity of the Na(+)/K(+)-ATPase. Furthermore, the direct effect of FAMEs on cell membrane was assessed on purified pig kidney Na(+)/K(+)-ATPase membranes, erythrocyte ghost membranes, and larvae membrane preparation. No modifications on total phospholipids and cholesterol content were found after FAMEs 20 min treatment on larvae membrane preparation, but only 360 µg/mL FAME 2 was able to decrease total phospholipid of erythrocyte ghost membrane. Moreover, only 60 and 360 µg/mL FAME 3 caused an activation of purified Na(+)/K(+)-ATPase, that was an opposite effect of FAMEs treatment in larvae membrane preparation, and caused an inhibition of the pump activity. These data together suggest that maybe FAMEs can modulate the Na(+)/K(+)-ATPase on intact larvae for such mechanisms and not for a direct effect, one time that the direct effect of FAMEs in membrane preparation decreased the activity of Na(+)/K(+)-ATPase. The biochemical changes caused by the compounds were significant and may negatively influence the development and survival of C. quinquefasciatus larvae. PMID:26993642

  7. Unique honey bee (Apis mellifera) hive component-based communities as detected by a hybrid of phospholipid fatty-acid and fatty-acid methyl ester analyses.

    PubMed

    Grubbs, Kirk J; Scott, Jarrod J; Budsberg, Kevin J; Read, Harry; Balser, Teri C; Currie, Cameron R

    2015-01-01

    Microbial communities (microbiomes) are associated with almost all metazoans, including the honey bee Apis mellifera. Honey bees are social insects, maintaining complex hive systems composed of a variety of integral components including bees, comb, propolis, honey, and stored pollen. Given that the different components within hives can be physically separated and are nutritionally variable, we hypothesize that unique microbial communities may occur within the different microenvironments of honey bee colonies. To explore this hypothesis and to provide further insights into the microbiome of honey bees, we use a hybrid of fatty acid methyl ester (FAME) and phospholipid-derived fatty acid (PLFA) analysis to produce broad, lipid-based microbial community profiles of stored pollen, adults, pupae, honey, empty comb, and propolis for 11 honey bee hives. Averaging component lipid profiles by hive, we show that, in decreasing order, lipid markers representing fungi, Gram-negative bacteria, and Gram-positive bacteria have the highest relative abundances within honey bee colonies. Our lipid profiles reveal the presence of viable microbial communities in each of the six hive components sampled, with overall microbial community richness varying from lowest to highest in honey, comb, pupae, pollen, adults and propolis, respectively. Finally, microbial community lipid profiles were more similar when compared by component than by hive, location, or sampling year. Specifically, we found that individual hive components typically exhibited several dominant lipids and that these dominant lipids differ between components. Principal component and two-way clustering analyses both support significant grouping of lipids by hive component. Our findings indicate that in addition to the microbial communities present in individual workers, honey bee hives have resident microbial communities associated with different colony components. PMID:25849080

  8. Enhanced catalysis and enantioselective resolution of racemic naproxen methyl ester by lipase encapsulated within iron oxide nanoparticles coated with calix[8]arene valeric acid complexes.

    PubMed

    Sayin, Serkan; Akoz, Enise; Yilmaz, Mustafa

    2014-09-14

    In this study, two types of nanoparticles have been used as additives for the encapsulation of Candida rugosa lipase via the sol-gel method. In one case, the nanoparticles were covalently linked with a new synthesized calix[8]arene octa valeric acid derivative (C[8]-C4-COOH) to produce new calix[8]arene-adorned magnetite nanoparticles (NP-C[8]-C4-COOH), and then NP-C[8]-C4-COOH was used as an additive in the sol-gel encapsulation process. In the other case, iron oxide nanoparticles were directly added into the sol-gel encapsulation process in order to interact electrostatically with both C[8]-C4-COOH and Candida rugosa lipase. The catalytic activities and enantioselectivities of two novel encapsulated lipases (Enc-NP-C[8]-C4-COOH and Enc-C[8]-C4-COOH@Fe3O4) in the hydrolysis reaction of racemic naproxen methyl ester were evaluated. The results showed that the activity and enantioselectivity of the lipase were improved when the lipase was encapsulated in the presence of calixarene-based additives. Indeed, the encapsulated lipases have an excellent rate of enantioselectivity, with E = 371 and 265, respectively, as compared to the free enzyme (E = 137). The lipases encapsulated with C[8]-C4-COOH and iron oxide nanoparticles (Enc-C[8]-C4-COOH@Fe3O4) retained more than 86% of their initial activities after 5 repeated uses and 92% with NP-C[8]-C4-COOH. PMID:25012138

  9. Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils.

    PubMed

    Schimmelmann, Arndt; Qi, Haiping; Coplen, Tyler B; Brand, Willi A; Fong, Jon; Meier-Augenstein, Wolfram; Kemp, Helen F; Toman, Blaza; Ackermann, Annika; Assonov, Sergey; Aerts-Bijma, Anita T; Brejcha, Ramona; Chikaraishi, Yoshito; Darwish, Tamim; Elsner, Martin; Gehre, Matthias; Geilmann, Heike; Gröning, Manfred; Hélie, Jean-François; Herrero-Martín, Sara; Meijer, Harro A J; Sauer, Peter E; Sessions, Alex L; Werner, Roland A

    2016-04-19

    An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.8 to +397.0 mUr or ‰, for δ(13)C(VPDB-LSVEC) from -40.81 to +0.49 mUr and for δ(15)N(Air) from -5.21 to +61.53 mUr. Many of the new RMs are amenable to gas and liquid chromatography. The RMs include triads of isotopically contrasting caffeines, C16 n-alkanes, n-C20-fatty acid methyl esters (FAMEs), glycines, and l-valines, together with polyethylene powder and string, one n-C17-FAME, a vacuum oil (NBS 22a) to replace NBS 22 oil, and a (2)H-enriched vacuum oil. A total of 11 laboratories from 7 countries used multiple analytical approaches and instrumentation for 2-point isotopic normalization against international primary measurement standards. The use of reference waters in silver tubes allowed direct normalization of δ(2)H values of organic materials against isotopic reference waters following the principle of identical treatment. Bayesian statistical analysis yielded the mean values reported here. New RMs are numbered from USGS61 through USGS78, in addition to NBS 22a. Because of exchangeable hydrogen, amino acid RMs currently are recommended only for carbon- and nitrogen-isotope measurements. Some amino acids contain (13)C and carbon-bound organic (2)H-enrichments at different molecular sites to provide RMs for potential site-specific isotopic analysis in future studies. PMID:26974360

  10. Effect of aliskiren, telmisartan and torsemide on cardiac dysfunction in l-nitro arginine methyl ester (l-NAME) induced hypertension in rats.

    PubMed

    Sadek, Sawsan A; Rashed, Laila A; Bassam, Amira M; Said, Eman S

    2015-11-01

    Comparative study of cardio protective effect of aliskiren, telmisartan, and torsemide was carried out on l-nitro arginine methyl ester (l-NAME) induced hypertension in rats. The three drugs were given daily for 8 weeks simultaneously with l-NAME, with a control group for each drug and l-NAME. The degree of protection was assessed by measurement of systolic blood pressure and heart rate of animals every two weeks. At the end of the experimental period blood sampling was carried out for estimation of the level of NO2 (-)/NO3 (-). After which animals were sacrificed for heart dissection to detect collagen types I and III gene expression. Histopathological study was done to evaluate the extension of collagen deposits. The study revealed that the three drugs decreased blood pressure significantly compared to l-NAME. There was no significant difference between aliskiren and telmisartan in all measurements, but there was significant decrease in measurements of both aliskiren and telmisartan treated groups compared to torsemide starting from 4th week. There were insignificant changes in pulse rate values between the three l-NAME treated groups through the experiment. The three drugs significantly increased NO compared to l-NAME. Collagen I and III gene expression was significantly decreased by the three drugs but the highest percentage of inhibition was with telmisartan compared to l-NAME. Comparing the percentage inhibition of cardiac fibrosis, there was insignificant difference between telmisartan and torsemide treated groups while both were superior to aliskiren. In conclusion, further experimental studies are required to elucidate the potential cardioprotective mechanisms of aliskiren, telmisartan and torsemide, and assess their efficacy in treatment of heart failure. PMID:26644935

  11. Unique Honey Bee (Apis mellifera) Hive Component-Based Communities as Detected by a Hybrid of Phospholipid Fatty-Acid and Fatty-Acid Methyl Ester Analyses

    PubMed Central

    2015-01-01

    Microbial communities (microbiomes) are associated with almost all metazoans, including the honey bee Apis mellifera. Honey bees are social insects, maintaining complex hive systems composed of a variety of integral components including bees, comb, propolis, honey, and stored pollen. Given that the different components within hives can be physically separated and are nutritionally variable, we hypothesize that unique microbial communities may occur within the different microenvironments of honey bee colonies. To explore this hypothesis and to provide further insights into the microbiome of honey bees, we use a hybrid of fatty acid methyl ester (FAME) and phospholipid-derived fatty acid (PLFA) analysis to produce broad, lipid-based microbial community profiles of stored pollen, adults, pupae, honey, empty comb, and propolis for 11 honey bee hives. Averaging component lipid profiles by hive, we show that, in decreasing order, lipid markers representing fungi, Gram-negative bacteria, and Gram-positive bacteria have the highest relative abundances within honey bee colonies. Our lipid profiles reveal the presence of viable microbial communities in each of the six hive components sampled, with overall microbial community richness varying from lowest to highest in honey, comb, pupae, pollen, adults and propolis, respectively. Finally, microbial community lipid profiles were more similar when compared by component than by hive, location, or sampling year. Specifically, we found that individual hive components typically exhibited several dominant lipids and that these dominant lipids differ between components. Principal component and two-way clustering analyses both support significant grouping of lipids by hive component. Our findings indicate that in addition to the microbial communities present in individual workers, honey bee hives have resident microbial communities associated with different colony components. PMID:25849080

  12. Liquid chromatography/tandem mass spectrometry method for simultaneous determination of cocaine and its metabolite (-)ecgonine methyl ester in human acidified stabilized plasma samples.

    PubMed

    Liu, Yongzhen; Zheng, Bo; Strafford, Stephanie; Orugunty, Ravi; Sullivan, Michael; Gus, Jeffrey; Heidbreder, Christian; Fudala, Paul J; Nasser, Azmi

    2014-06-15

    Two simple, sensitive and rapid liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods (low range and high range) were developed and validated for the quantification of cocaine and its metabolite (-)ecgonine methyl ester (EME) in human acidified stabilized plasma samples. In the low range assay, cocaine and the internal standard, cocaine-D3, were extracted using a single step liquid-liquid extraction from human acidified stabilized plasma. For the high range assay, human acidified stabilized plasma containing cocaine, EME, and the internal standards, cocaine-D3 and EME-D3, was mixed with acetonitrile, and the protein precipitate was separated by centrifugation. Both cocaine and EME extracted from both assays were separated on a HILIC column and detected in positive ion mode using multiple reaction monitoring (MRM). Both methods were validated and the specificity, linearity, lower limit of quantitation (LLOQ), precision, accuracy, recoveries and stability were determined. The linear range for the low range assay was 0.01-5ng/mL for cocaine; in the high range assay values were 5-1000ng/mL for cocaine and 1-200ng/mL for EME. The correlation coefficient (R(2)) values for both assays were 0.993 or greater. The precision and accuracy for intra-day and inter-day were better than 13.0%. The recovery was above 85% and matrix effects were low with the matrix factor ranging from 0.817 to 1.10 for both analytes in both assays. The validated methods were successfully used to quantify the plasma concentrations of cocaine and EME in clinical pharmacokinetic and pharmacodynamic studies. PMID:24861875

  13. Neuroprotective Role of L-NG-Nitroarginine Methyl Ester (L-NAME) against Chronic Hypobaric Hypoxia with Crowding Stress (CHC) Induced Depression-Like Behaviour.

    PubMed

    Deep, Satya Narayan; Baitharu, Iswar; Sharma, Apurva; Gurjar, Anoop Kishor Singh; Prasad, Dipti; Singh, Shashi Bala

    2016-01-01

    Improper neuroimmune responses following chronic stress exposure have been reported to cause neuronal dysfunctions leading to memory impairment, anxiety and depression like behaviours. Though several factors affecting microglial activation and consequent alteration in neuro-inflammatory responses have been well studied, role of NO and its association with microglia in stress induced depression model is yet to be explored. In the present study, we validated combination of chronic hypobaric hypoxia and crowding (CHC) as a stress model for depression and investigated the role of chronic stress induced elevated nitric oxide (NO) level in microglia activation and its effect on neuro-inflammatory responses in brain. Further, we evaluated the ameliorative effect of L-NG-Nitroarginine Methyl Ester (L-NAME) to reverse the stress induced depressive mood state. Four groups of male Sprague Dawley rat were taken and divided into control and CHC stress exposed group with and without treatment of L-NAME. Depression like behaviour and anhedonia in rats were assessed by Forced Swim Test (FST) and Sucrose Preference Test (SPT). Microglial activation was evaluated using Iba-1 immunohistochemistry and proinflammatory cytokines were assessed in the hippocampal region. Our result showed that exposure to CHC stress increased the number of active microglia with corresponding increase in inflammatory cytokines and altered behavioural responses. The inhibition of NO synthesis by L-NAME during CHC exposure decreased the number of active microglia in hippocampus as evident from decreased Iba-1 positive cells. Further, L-NAME administration decreased pro-inflammatory cytokines in hippocampus and improved behaviour of rats. Our study demonstrate that stress induced elevation of NO plays pivotal role in altered microglial activation and consequent neurodegenerative processes leading to depression like behaviour in rat. PMID:27082990

  14. Simultaneous determination of 4-methyl-piperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride and its major metabolite in rats by HPLC.

    PubMed

    Jiang, Xiaomei; Bai, Yihao; Ling, Xiaomei; Han, Fangbin; Li, Runtao; Cui, Jingrong

    2010-02-01

    A method for the simultaneous determination of TM208 and its major metabolite (sulfine 4-methyl-piperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester, TM208-SO) was developed and validated for the first time. The analytes were extracted from plasma samples by liquid-liquid extraction and analyzed using high-performance liquid chromatography. Flunarizine hydrochloride was used as the internal standard. Chromatographic separations were performed on a Diamonsil C(18) analytical column. The mobile phases consisted of 20 mM ammonium acetate adjusted to pH 4.20 with acetic acid (solvent A) and acetonitrile (solvent B). The analytes were detected at 254 nm after linear gradient elution. The flow rate was 0.8 mL/min. Linearity was obtained over the concentration range of 0.104-5.20 microg/mL for TM208 and 0.145-5.80 microg/mL for TM208-SO in rat plasma. The limit of quantification was 0.104 microg/mL for TM208 and 0.145 microg/mL for TM208-SO, respectively. The inter- and intra-day precision was less than 12.8% for TM208 and 14.1% for TM208-SO. And the accuracy was 96.2-111.1% for TM208 and 95.5-108.6% for TM208-SO. This analytic procedure was applied to a pharmacokinetic study of TM208 and TM208-SO in rats, and the pharmacokinetic parameters were calculated. PMID:20109290

  15. Thermo- and pH-sensitive gel membranes based on poly-(acryloyl- L-proline methyl ester)- graft-poly(acrylic acid) for selective permeation of metal ions

    NASA Astrophysics Data System (ADS)

    Hasegawa, Shin; Ohashi, Hitoshi; Maekawa, Yasunari; Katakai, Ryoichi; Yoshida, Masaru

    2005-04-01

    Thermo- and pH-responsive gel membranes were synthesized by γ-ray grafting of pH-responsive poly(acrylic acid) (AAc) onto thermo-responsive polymer gel of acryloyl- L-proline methyl ester (A-ProOMe). The gel membranes of poly(A-ProOMe) with 15 mol% graft chains of AAc exhibited both thermo- and pH-responses. Under the condition (pH 6.0, 30°C) in which the thermo-sensitive unit shrinks and the pH-sensitive unit swells, the selective permeation of Li ion over Co and Ni ions can be achieved.

  16. NG-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis, ameliorates interleukin 2-induced capillary leakage and reduces tumour growth in adenocarcinoma-bearing mice.

    PubMed Central

    Orucevic, A.; Lala, P. K.

    1996-01-01

    We tested whether NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, can prevent interleukin 2 (IL-2)-induced capillary leakage in tumour-bearing mice without compromising the therapeutic benefits of IL-2. C3H/HeJ female mice transplanted s.c. with 2.5 x 10(5) C3-L5 mammary carcinoma cells were treated with: nothing, IL-2 (ten injections of 15,000 Cetus units i.p. every 8 h), L-NAME (0.1, 0.5, or 1 mg ml-1 drinking water), IL-2 + L-NAME (0.1 or 0.5 or 1 mg ml-1 drinking water). Therapies were given in one round (IL-2, days 10-13; L-NAME, days 9-13) or in two rounds (IL-2, days 10-13 and 20-23; L-NAME, days 9-13 and days 19-23) after tumour transplantation. Capillary leakage was measured from the water contents of the pleural cavities, lungs, spleen and kidneys. Effects of the therapies on the primary tumour size and the number of spontaneous lung metastases were also recorded. NO production was measured as the nitrite + nitrate levels in the serum and in the pleural effusion. After the first round of therapies, addition of L-NAME significantly reduced IL-2-induced pulmonary oedema and water retention in the spleen in a dose-dependent manner. It also significantly reduced the IL-2-induced rise in NO levels in the serum and pleural fluid, but did not affect IL-2-induced pleural effusion or water retention in the kidney. At later stages of tumour growth (day 23), tumours themselves induced significant fluid retention in the lungs and the kidney, which was not aggravated further with the second round of IL-2 therapy. At this time, L-NAME therapy alone ameliorated tumour-induced pulmonary oedema. During both rounds of therapy different doses of L-NAME alone caused a reduction of primary tumour growth as well as spontaneous lung metastases, which improved further with the addition of IL-2. The combination therapy was at least as effective as IL-2 therapy. In summary, L-NAME had anti-tumour effects in vivo, reduced the severity of IL-2

  17. The effect of L-arginine methyl ester on indices of free radical involvement in a rat model of experimental nephrocalcinosis.

    PubMed

    Ozturk, Hayrettin; Ozturk, Hulya; Yagmur, Yusuf; Buyukbayram, Huseyin

    2006-10-01

    The aim of this study was to test the effect of L: -arginine methyl ester (L-Arg) on indices of free radical involvement in a rat model of experimental nephrocalcinosis. Twenty-eight Sprague-Dawley rats were randomized into four groups of seven. The first group (G1), the sham-control group received pure distilled drinking water. The second group (G2) received drinking water containing 0.7% ethylene glycol (EG) in distilled water for 3 weeks. The third group (G3) received drinking water containing 0.7% EG in distilled water for 3 weeks and L-Arg was administered for 3 weeks. The fourth group (G4) received drinking water containing 0.7% EG in distilled water for 3 weeks and L-NAME was administered for 3 weeks. Urine and aortic blood was collected to determine some parameters. The kidneys were also removed for histological examination. The increase in blood urea nitrogen, serum creatinine, K(+), Mg(2+ )and uric acid were mild in group 3 compared with the groups 2 and 4. The urinary concentrations of Na(+), K(+), Mg(2+) and uric acid were noticed to be similar among the groups. However, Ca(2+ )and oxalate excretion were significantly higher in groups 2, 3 and 4 than in group 1. The mean values of SOD, CAT and GSH-Px values were significantly increased in group 3 when compared to groups 2 and 4. Presence of aggregated urinary crystals was clearer in experimental groups compared to group 1. The tubular dilatation, epithelial degeneration and lymphocytic infiltration were significantly found in groups 2 and 4. Mild tissue damage was observed in L-Arg-pretreated rats. Under polarized light microscope intense crystals in the cortex and medulla were observed in the kidney of group 2 and 4 and moderate crystals were noticed in group 3. In conclusion, L-Arg supplementation may decrease free radicals and tubulary membrane injury in nephrocalcinosis due to infiltrating leukocytes and decreased antioxidant enzyme activities in rats fed with EG diet. PMID:16823549

  18. Scattering and Spectroscopic Study on the Hydration and Phase Behavior of Aqueous Alcohol Ethoxylate and Methyl Ester Ethoxylate: Effects of Terminal Groups in Hydrophilic Chains.

    PubMed

    Sato, Takaaki; Akahane, Takesi; Amano, Kenshi; Hyodo, Ryo; Yanase, Keiichi; Ogura, Taku

    2016-06-23

    Using dielectric relaxation spectroscopy (DRS), small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and viscometry, we have investigated the hydration behavior, static structures, Brownian dynamics, and mechanical properties of aqueous solutions of alcohol ethoxylate (C12E15) and methyl ester ethoxylate (C12MEE), hereafter abbreviated as AE and MEE, respectively, in which we especially focus on the effects of the endcaps of these nonionic surfactants. We find that AE and MEE exhibit fairly different phase behaviors in water: AE produces liquid crystalline phases at w (surfactant weight fraction) > 0.35, whereas MEE retains a liquid phase in an extremely wide concentration range (w < 0.7) at ambient temperature. The structure factor deduced from SAXS intensities using a generalized indirect Fourier transformation technique and the effective hydration number evaluated from the negative excess bulk water relaxation amplitude revealed by DRS unambiguously demonstrate that hydration water molecules, exhibiting about 4-times-slower collective reorientational dynamics than that of bulk water, contribute to the excluded volume of the micelles. The blocked terminal hydrogen-bond donor/acceptor site of MEE leads to smaller hydration number of MEE than compared to that of AE, and consequently the lower excluded volume of the MEE micelles. The effective micellar volume fraction, ϕ(eff), should be defined by incorporating such different hydration effects. Importantly, voluminosity, defined as the micellar volume fraction per unit mass, is clearly a decreasing function of w, demonstrating progressive dehydration at a higher w. The collective diffusion constants determined by DLS for the AE and MEE micelles show a monotonous increase up to ϕ(eff) ≈ 0.5, as expected for the hard spheres. Low-shear-rate viscosities follow a Krieger-Dougherty model in the identical micellar packing fraction range. All static, dynamic, and mechanical properties of these micellar

  19. Synthesis, crystal structure, computational study of 1-(6-chloro-pyridin-2-yl)-5-hydroxy-1H-pyrazole-3-carboxylic acid methyl ester and its 5-acetoxy analogs

    NASA Astrophysics Data System (ADS)

    Shen, Li-Qun; Huang, Su-Yu; Diao, Kai-Sheng; Lei, Fu-Hou

    2012-08-01

    Two new pyrazole derivatives of 1-(6-chloro-pyridin-2-yl)-5-hydroxy-1H-pyrazole-3-carboxylic acid methyl ester 1a and 5-acetoxy-1-(6-chloro-pyridin-2-yl)-1H-pyrazole-3-carboxylic acid methyl ester 2 were synthesized and characterized by 1H, 13C NMR, IR spectroscopies and HRMS analyses. The molecular structure of 1a and 2 were studied by X-ray diffraction and compared to density-functional-theory (DFT) calculations. The gauge-including atomic orbital (GIAO) method for calculating 1H and 13C NMR nuclear magnetic shielding tensors at the DFT method with 6-31+G* basis set were applied to the compounds 1a and 2. Additionally, thermodynamic properties of the cyclization of the compound 3 to these compounds (1a, 1b, 1c, 4) were investigated by theoretical calculations. These theoretical calculations was shown that the compound 1a was readily formed and was the most stable one. Tautomeric forms of the compound 1a were optimized at the same methods and basis set. The calculated relative Gibbs free energies of the tautomeric forms of 1a were used to estimate the equilibrium constants. It was shown that the 1a was the most stable than tautomer of 1b and 1c in the gas phase.

  20. 40 CFR 721.9530 - Bis(2,2,6,6-tetra-methyl-piper-idinyl) ester of cycloalkyl spir-o-ke-tal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) ester of cycloalkyl spir-o-ke-tal. 721.9530 Section 721.9530 Protection of Environment ENVIRONMENTAL... of cycloalkyl spir-o-ke-tal. (a) Chemical substance and significant new uses subject to reporting. (1...-clo-alkyl spir-o-ke-tal (PMN P-88-0083) is subject to reporting under this section for the...

  1. 40 CFR 721.9530 - Bis(2,2,6,6-tetra-methyl-piper-idinyl) ester of cycloalkyl spir-o-ke-tal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) ester of cycloalkyl spir-o-ke-tal. 721.9530 Section 721.9530 Protection of Environment ENVIRONMENTAL... of cycloalkyl spir-o-ke-tal. (a) Chemical substance and significant new uses subject to reporting. (1...-clo-alkyl spir-o-ke-tal (PMN P-88-0083) is subject to reporting under this section for the...

  2. 40 CFR 721.9530 - Bis(2,2,6,6-tetra-methyl-piper-idinyl) ester of cycloalkyl spir-o-ke-tal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) ester of cycloalkyl spir-o-ke-tal. 721.9530 Section 721.9530 Protection of Environment ENVIRONMENTAL... of cycloalkyl spir-o-ke-tal. (a) Chemical substance and significant new uses subject to reporting. (1...-clo-alkyl spir-o-ke-tal (PMN P-88-0083) is subject to reporting under this section for the...

  3. 40 CFR 721.9530 - Bis(2,2,6,6-tetra-methyl-piper-idinyl) ester of cycloalkyl spir-o-ke-tal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) ester of cycloalkyl spir-o-ke-tal. 721.9530 Section 721.9530 Protection of Environment ENVIRONMENTAL... of cycloalkyl spir-o-ke-tal. (a) Chemical substance and significant new uses subject to reporting. (1...-clo-alkyl spir-o-ke-tal (PMN P-88-0083) is subject to reporting under this section for the...

  4. 40 CFR 721.9530 - Bis(2,2,6,6-tetra-methyl-piper-idinyl) ester of cycloalkyl spir-o-ke-tal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) ester of cycloalkyl spir-o-ke-tal. 721.9530 Section 721.9530 Protection of Environment ENVIRONMENTAL... of cycloalkyl spir-o-ke-tal. (a) Chemical substance and significant new uses subject to reporting. (1...-clo-alkyl spir-o-ke-tal (PMN P-88-0083) is subject to reporting under this section for the...

  5. Graphene composite for improvement in the conversion efficiency of flexible poly 3-hexyl-thiophene:[6,6]-phenyl C{sub 71} butyric acid methyl ester polymer solar cells

    SciTech Connect

    Chauhan, A. K. E-mail: akc.barc@gmail.com; Gusain, Abhay; Jha, P.; Koiry, S. P.; Saxena, Vibha; Veerender, P.; Aswal, D. K.; Gupta, S. K.

    2014-03-31

    The solution of thin graphene-sheets obtained from a simple ultrasonic exfoliation process was found to chemically interact with [6,6]-phenyl C{sub 71} butyric acid methyl ester (PCBM) molecules. The thinner graphene-sheets have significantly altered the positions of highest occupied molecular orbital and lowest unoccupied molecular orbital of PCBM, which is beneficial for the enhancement of the open circuit voltage of the solar cells. Flexible bulk heterojunction solar cells fabricated using poly 3-hexylthiophene (P3HT):PCBM-graphene exhibited a power conversion efficiency of 2.51%, which is a ∼2-fold increase as compared to those fabricated using P3HT:PCBM. Inclusion of graphene-sheets not only improved the open-circuit voltage but also enhanced the short-circuit current density owing to an improved electron transport.

  6. Constrained photophysics of partially and fully encapsulated charge transfer probe (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester inside cyclodextrin nano-cavities: Evidence of cyclodextrins cavity dependent complex stoichiometry

    NASA Astrophysics Data System (ADS)

    Ghosh, Shalini; Jana, Sankar; Guchhait, Nikhil

    2011-12-01

    The polarity sensitive intra-molecular charge transfer (ICT) emission from (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester (MAPAME) is found to show distinct changes once introduced into the nano-cavities of cyclodextrins in aqueous environment. Movement of the molecule from the more polar aqueous environment to the less polar, hydrophobic cyclodextrin interior is marked by the blue shift of the CT emission band with simultaneous fluorescence intensity enhancement. The emission spectral changes on complexation with the α- and β-CD show different stoichiometries as observed from the Benesi-Hildebrand plots. Fluorescence anisotropy and lifetime measurements were performed to probe the different behaviors of MAPAME in aqueous α- and β-CD solutions.

  7. Constrained photophysics of partially and fully encapsulated charge transfer probe (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester inside cyclodextrin nano-cavities: evidence of cyclodextrins cavity dependent complex stoichiometry.

    PubMed

    Ghosh, Shalini; Jana, Sankar; Guchhait, Nikhil

    2011-12-15

    The polarity sensitive intra-molecular charge transfer (ICT) emission from (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester (MAPAME) is found to show distinct changes once introduced into the nano-cavities of cyclodextrins in aqueous environment. Movement of the molecule from the more polar aqueous environment to the less polar, hydrophobic cyclodextrin interior is marked by the blue shift of the CT emission band with simultaneous fluorescence intensity enhancement. The emission spectral changes on complexation with the α- and β-CD show different stoichiometries as observed from the Benesi-Hildebrand plots. Fluorescence anisotropy and lifetime measurements were performed to probe the different behaviors of MAPAME in aqueous α- and β-CD solutions. PMID:21996591

  8. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2..., polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2-propenoate. (a) Chemical...-propenoic acid, 2-methyl-, 1,1′- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene,...

  9. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2..., polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2-propenoate. (a) Chemical...-propenoic acid, 2-methyl-, 1,1′- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene,...

  10. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2..., polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2-propenoate. (a) Chemical...-propenoic acid, 2-methyl-, 1,1′- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene,...

  11. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2..., polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2-propenoate. (a) Chemical...-propenoic acid, 2-methyl-, 1,1′- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene,...

  12. Plant-mediated stereoselective biotransformation of phenylglyoxylic acid esters.

    PubMed

    Maczka, Wanda Krystyna; Grabarczyk, Małgorzata; Wińska, Katarzyna; Anioł, Mirosław

    2014-01-01

    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

  13. A region of the rat N-methyl-D-aspartate receptor 2A subunit that is sufficient for potentiation by phorbol esters.

    PubMed

    Grant, E R; Guttmann, R P; Seifert, K M; Lynch, D R

    2001-09-01

    N-methyl-D-aspartate (NMDA) receptors are modulated by protein kinase C (PKC) in vivo and in heterologous expression systems. In heterologous expression systems, PKC-mediated modulation is subunit specific with NR2A-containing receptors being potentiated by phorbol 12-myristate 13-acetate (PMA), while NR2C-containing receptors are inhibited or unaffected. In the present study we have produced chimeric receptors containing NR2A and NR2C to define the components of NR2A which are sufficient for potentiation by PMA. Amino acids 1105-1400 of NR2A placed onto the C-terminus of NR2C at amino acid 1102 was the minimum region sufficient for producing a PMA-stimulated receptor. This suggests that this region contains structural determinants for PKC-mediated potentiation of NR2A receptors. PMID:11524145

  14. 40 CFR 721.4486 - Propanoic acid, 2-methyl-, (1R,2R,4R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl ester, rel-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...,4R)-1,7,7-trimethylbicyclo hept-2-yl ester, rel-. (a) Chemical substance and significant new uses...)-1,7,7-trimethylbicyclo hept-2-yl ester, rel-. 721.4486 Section 721.4486 Protection of Environment...,7-trimethylbicyclo hept-2-yl ester, rel- (PMNs P-98-0497 and P-98-0509; CAS No. 85586-67-0)...

  15. Dimethyl carbonate-mediated lipid extraction and lipase-catalyzed in situ transesterification for simultaneous preparation of fatty acid methyl esters and glycerol carbonate from Chlorella sp. KR-1 biomass.

    PubMed

    Jo, Yoon Ju; Lee, Ok Kyung; Lee, Eun Yeol

    2014-04-01

    Fatty acid methyl esters (FAMEs) and glycerol carbonate were simultaneously prepared from Chlorella sp. KR-1 containing 40.9% (w/w) lipid using a reactive extraction method with dimethyl carbonate (DMC). DMC was used as lipid extraction agent, acyl acceptor for transesterification of the extracted triglycerides, substrate for glycerol carbonate synthesis from glycerol, and reaction medium for the solvent-free reaction system. For 1g of biomass, 367.31 mg of FAMEs and 16.73 mg of glycerol carbonate were obtained under the optimized conditions: DMC to biomass ratio of 10:1 (v/w), water content of 0.5% (v/v), and Novozyme 435 to biomass ratio of 20% (w/w) at 70°C for 24h. The amount of residual glycerol was only in the range of 1-2.5mg. Compared to conventional method, the cost of FAME production with the proposed technique could be reduced by combining lipid extraction with transesterification and omitting the extraction solvent recovery process. PMID:24583221

  16. Synthesis of fatty acid methyl ester from the transesterification of high- and low-acid-content crude palm oil (Elaeis guineensis) and karanj oil (Pongamia pinnata) over a calcium-lanthanum-aluminum mixed-oxides catalyst.

    PubMed

    Syamsuddin, Y; Murat, M N; Hameed, B H

    2016-08-01

    The synthesis of fatty acid methyl ester (FAME) from the high- and low-acid-content feedstock of crude palm oil (CPO) and karanj oil (KO) was conducted over CaO-La2O3-Al2O3 mixed-oxide catalyst. Various reaction parameters were investigated using a batch reactor to identify the best reaction condition that results in the highest FAME yield for each type of oil. The transesterification of CPO resulted in a 97.81% FAME yield with the process conditions of 170°C reaction temperature, 15:1 DMC-to-CPO molar ratio, 180min reaction time, and 10wt.% catalyst loading. The transesterification of KO resulted in a 96.77% FAME yield with the conditions of 150°C reaction temperature, 9:1 DMC-to-KO molar ratio, 180min reaction time, and 5wt.% catalyst loading. The properties of both products met the ASTM D6751 and EN 14214 standard requirements. The above results showed that the CaO-La2O3-Al2O3 mixed-oxide catalyst was suitable for high- and low-acid-content vegetable oil. PMID:27136612

  17. Rosmarinic Acid Methyl Ester Inhibits LPS-Induced NO Production via Suppression of MyD88- Dependent and -Independent Pathways and Induction of HO-1 in RAW 264.7 Cells.

    PubMed

    So, Yangkang; Lee, Seung Young; Han, Ah-Reum; Kim, Jin-Baek; Jeong, Hye Gwang; Jin, Chang Hyun

    2016-01-01

    In this study, we investigated the anti-inflammatory effect of rosmarinic acid methyl ester (RAME) isolated from a mutant cultivar of Perilla frutescens (L.) Britton. We found that RAME inhibits lipopolysaccharide (LPS)-induced nitric oxide (NO) production, with an IC50 of 14.25 µM, in RAW 264.7 cells. RAME inhibited the LPS-induced expression of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, monocyte chemoattractant protein-1, interferon-β, and inducible nitric oxide synthase (iNOS). Moreover, RAME suppressed the activation of nuclear factor kappa B. These results suggest that the downregulation of iNOS expression by RAME was due to myeloid differentiation primary response gene 88 (MyD88)-dependent and -independent pathways. Furthermore, RAME induced the expression of heme oxygenase-1 (HO-1) through activation of nuclear factor-erythroid 2-related factor 2. Treatment with tin protoporphyrin, an inhibitor of HO-1, reversed the RAME-induced suppression of NO production. Taken together, RAME isolated from P. frutescens inhibited NO production in LPS-treated RAW 264.7 cells through simultaneous induction of HO-1 and inhibition of MyD88-dependent and -independent pathways. PMID:27548124

  18. The Dependence of Donor:Acceptor Ratio on the Photovoltaic Performances of Blended poly (3-octylthiophene-2,5-diyl) and (6,6)-phenyl C{sub 71} butyric acid methyl ester Bulk Heterojunction Organic Solar Cells

    SciTech Connect

    Fauzia, Vivi; Umar, Akrajas Ali; Salleh, Muhamad Mat; Yahya, Muhammad

    2010-10-24

    Bulk heterojunction organic solar cells using blended poly (3-octylthiophene-2,5-diyl)(P3OT) and (6,6)-phenyl C{sub 71} butyric acid methyl ester (PC{sub 71}BM) have been fabricated. P3OT and PC{sub 71}BM were used as the electron donor (D) and acceptor (A), respectively. Both materials were mixed and dissolved in dichlorobenzene with three different D:A ratios i.e. 1:3, 1:1 and 3:1 (weight) while maintained at the concentration of 2 wt%(26 mg/ml). The blended thin films were sandwiched between the indium tin oxide (ITO) coated glass and the aluminum film. This paper reports the influence of donor:acceptor ratio on the performance of solar cell devices measured by current-voltage measurement both in the dark and under 1.5 AM solar illumination. It was found that all devices showed the photovoltaic effect with poor diode behavior and the donor:acceptor ratio significantly influenced on the performance of bulk heterojunction organic solar cells.

  19. The Dependence of Donor:Acceptor Ratio on the Photovoltaic Performances of Blended poly (3-octylthiophene-2,5-diyl) and (6,6)-phenyl C71 butyric acid methyl ester Bulk Heterojunction Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Fauzia, Vivi; Umar, Akrajas Ali; Salleh, Muhamad Mat; Yahya, Muhammad

    2010-10-01

    Bulk heterojunction organic solar cells using blended poly (3-octylthiophene-2,5-diyl)(P3OT) and (6,6)-phenyl C71 butyric acid methyl ester (PC71BM) have been fabricated. P3OT and PC71BM were used as the electron donor (D) and acceptor (A), respectively. Both materials were mixed and dissolved in dichlorobenzene with three different D:A ratios i.e. 1:3, 1:1 and 3:1 (weight) while maintained at the concentration of 2 wt% (26 mg/ml). The blended thin films were sandwiched between the indium tin oxide (ITO) coated glass and the aluminum film. This paper reports the influence of donor:acceptor ratio on the performance of solar cell devices measured by current-voltage measurement both in the dark and under 1.5 AM solar illumination. It was found that all devices showed the photovoltaic effect with poor diode behavior and the donor:acceptor ratio significantly influenced on the performance of bulk heterojunction organic solar cells.

  20. Density functional study of electronic, charge density, and chemical bonding properties of 9-methyl-3-Thiophen-2-YI-Thieno [3,2-e] [1, 2, 4] Thriazolo [4,3-c] pyrimidine-8-Carboxylic acid ethyl ester crystals

    NASA Astrophysics Data System (ADS)

    Reshak, A. H.; Kamarudin, H.; Alahmed, Z. A.; Auluck, S.; Chyský, Jan

    2014-06-01

    A comprehensive theoretical density functional investigation of the electronic crystal structure, chemical bonding, and the electron charge densities of 9-Methyl-3-Thiophen-2-YI-Thieno [3, 2-e] [1, 2, 4] Thriazolo [4,3-c] Pyrimidine-8-Carboxylic Acid Ethyl Ester (C15H12N4O2S2) is performed. The density of states at Fermi level equal to 5.50 (3.45) states/Ry cell, and the calculated bare electronic specific heat coefficient is found to be 0.95 (0.59) mJ/mole-K2 for the local density approximation (Engel-Vosko generalized gradient approximation). The electronic charge density space distribution contours in (1 0 0) and (1 1 0) planes were calculated. We find that there are two independent molecules (A and B) in the asymmetric unit exhibit intramolecular C-H…O, C-H…N interactions. This intramolecular interaction is different in molecules A and B, where A molecule show C-H…O interaction while B molecule exhibit C-H…N interaction. We should emphasis that there is π-π interaction between the pyrimidine rings of the two neighbors B molecules gives extra strengths and stabilizations to the superamolecular structure. The calculated distance between the two neighbors pyrimidine rings found to be 3.345 Å, in good agreement with the measured one (3.424(1) Å).

  1. (6E,10E) Isopolycerasoidol and (6E,10E) Isopolycerasoidol Methyl Ester, Prenylated Benzopyran Derivatives from Pseuduvaria monticola Induce Mitochondrial-Mediated Apoptosis in Human Breast Adenocarcinoma Cells

    PubMed Central

    Taha, Hairin; Looi, Chung Yeng; Arya, Aditya; Wong, Won Fen; Yap, Lee Fah; Hasanpourghadi, Mohadeseh; Mohd, Mustafa A.; Paterson, Ian C; Mohd Ali, Hapipah

    2015-01-01

    Phytochemicals from Pseuduvaria species have been reported to display a wide range of biological activities. In the present study, a known benzopyran derivative, (6E,10E) isopolycerasoidol (1), and a new benzopyran derivative, (6E,10E) isopolycerasoidol methyl ester (2), were isolated from a methanol extract of Pseuduvaria monticola leaves. The structures of the isolated compounds were elucidated by spectroscopic methods including 1D and 2D NMR, IR, UV, and LCMS-QTOF, and by comparison with previously published data. The anti-proliferative and cytotoxic effects of these compounds on human breast cancer cell-lines (MCF-7 and MDA-MB-231) and a human normal breast epithelial cell line (MCF-10A) were investigated. MTT results revealed both (1) and (2) were efficient in reducing cell viability of breast cancer cells. Flow cytometry analysis demonstrated that (1) and (2) induced cell death via apoptosis, as demonstrated by an increase in phosphotidylserine exposure. Both compounds elevated ROS production, leading to reduced mitochondrial membrane potential and increased plasma membrane permeability in breast cancer cells. These effects occurred concomitantly with a dose-dependent activation of caspase 3/7 and 9, a down-regulation of the anti-apoptotic gene BCL2 and the accumulation of p38 MAPK in the nucleus. Taken together, our data demonstrate that (1) and (2) induce intrinsic mitochondrial-mediated apoptosis in human breast cancer cells, which provides the first pharmacological evidence for their future development as anticancer agents. PMID:25946039

  2. (6E,10E) Isopolycerasoidol and (6E,10E) Isopolycerasoidol Methyl Ester, Prenylated Benzopyran Derivatives from Pseuduvaria monticola Induce Mitochondrial-Mediated Apoptosis in Human Breast Adenocarcinoma Cells.

    PubMed

    Taha, Hairin; Looi, Chung Yeng; Arya, Aditya; Wong, Won Fen; Yap, Lee Fah; Hasanpourghadi, Mohadeseh; Mohd, Mustafa A; Paterson, Ian C; Mohd Ali, Hapipah

    2015-01-01

    Phytochemicals from Pseuduvaria species have been reported to display a wide range of biological activities. In the present study, a known benzopyran derivative, (6E,10E) isopolycerasoidol (1), and a new benzopyran derivative, (6E,10E) isopolycerasoidol methyl ester (2), were isolated from a methanol extract of Pseuduvaria monticola leaves. The structures of the isolated compounds were elucidated by spectroscopic methods including 1D and 2D NMR, IR, UV, and LCMS-QTOF, and by comparison with previously published data. The anti-proliferative and cytotoxic effects of these compounds on human breast cancer cell-lines (MCF-7 and MDA-MB-231) and a human normal breast epithelial cell line (MCF-10A) were investigated. MTT results revealed both (1) and (2) were efficient in reducing cell viability of breast cancer cells. Flow cytometry analysis demonstrated that (1) and (2) induced cell death via apoptosis, as demonstrated by an increase in phosphotidylserine exposure. Both compounds elevated ROS production, leading to reduced mitochondrial membrane potential and increased plasma membrane permeability in breast cancer cells. These effects occurred concomitantly with a dose-dependent activation of caspase 3/7 and 9, a down-regulation of the anti-apoptotic gene BCL2 and the accumulation of p38 MAPK in the nucleus. Taken together, our data demonstrate that (1) and (2) induce intrinsic mitochondrial-mediated apoptosis in human breast cancer cells, which provides the first pharmacological evidence for their future development as anticancer agents. PMID:25946039

  3. Creation and evaluation of a two-dimensional contour plot of fatty acid methyl esters after off-line coupling of reversed-phase HPLC and GC/EI-MS.

    PubMed

    Hauff, Simone; Vetter, Walter

    2010-04-01

    Fatty acid methyl esters obtained from a fish oil sample were fractionated by non-aqueous reversed-phase high-performance liquid chromatography (RP-HPLC) using three serially connected C(18)-columns and pure methanol as the eluent. The HPLC fractions were analyzed by gas chromatography-electron ionization mass spectrometry in the selected ion monitoring mode. Data analysis and visualization was performed by the creation of a two-dimensional (2D) contour plot, in which GC retention times were plotted against the HPLC fractions. The 2D contour plot resulted in a full resolution of more than 120 fatty acids. The fatty acids were arranged on predictable lines and curves in dependence of the number of carbons and double bonds. The 2D contour plot enabled both the recognition of unknown fatty acids (which were found off the lines and curves) and the prediction of the coordinates of known fatty acids. Finally, selected HPLC fractions were subjected to further experiments (hydrogenation, silver ion fractionation, specific GC/MS measurements) in order to verify the structural assignments predicted from the 2D contour plot. All in all, the structures of over 100 FAs could be assigned to the peaks detected in the 2D contour plots. PMID:20155411

  4. Rapid molecular assessment of the bioturbation extent in sandy soil horizons under pine using ester-bound lipids by on-line thermally assisted hydrolysis and methylation-gas chromatography/mass spectrometry.

    PubMed

    Nierop, Klaas G J; Verstraten, Jacobus M

    2004-01-01

    Each plant species has a unique chemical composition, and also within a given plant the various tissues differ from one another in their chemistry. These different compositions can be traced back after decay of the plant parts when they are transformed into soil organic matter (SOM). As a result, the composition of SOM reflects not only the plant origin, but also the various tissues, and the composition consequently provides an estimate of the contribution of above-ground vs. below-ground litter. From the latter distribution the extent of bioturbation (mixing of above-ground litter with the mineral soil) can be assessed. Application of thermally assisted hydrolysis and methylation (THM) using tetramethylammonium hydroxide (TMAH) and subsequent analysis by gas chromatography/mass spectrometry (GC/MS) releases all typical cutin- and suberin-derived aliphatic monomers (mono-, di- and trihydroxyalkanoic acids, alpha,omega-alkanedioic acids) as their methyl esters and/or ethers in a rapid manner. Using the distribution of omega-hydroxyalkanoic acids that are present in pine needle cutin (C(12) and C(14)) and not in root suberin, and those that are present in roots but not in needles (C(20) and C(22)), the extent of bioturbation (mixing of above-ground plant litter with the mineral soil) can be assessed. Similarly, the (9,16-dihydroxyhexadecanoic acid+9,10,18-trihydroxyoctadecanoic acid)/(C(20) + C(22) alpha,omega-alkanedioic acids) ratio reflects the degree of bioturbation. Three mineral soil profiles under Corsican pine with an A horizon that exhibited extensive bioturbation phenomena, and underlying C horizons with hardly any or no bioturbation, were investigated in order to examine the applicability of such an approach. It appeared that the A horizons contained all four mentioned omega-hydroxyalkanoic acids, while the C horizons contained virtually only the C(20) and C(22) members. The results not only suggest that bioturbation occurs in the A horizons, but also that

  5. Anti-nociceptive and anti-inflammatory activities of 4-[(1-phenyl-1H-pyrazol-4-yl) methyl] 1-piperazine carboxylic acid ethyl ester: A new piperazine derivative.

    PubMed

    Silva, Daiany P B; Florentino, Iziara F; Oliveira, Lanussy P; Lino, Roberta C; Galdino, Pablinny M; Menegatti, Ricardo; Costa, Elson A

    2015-10-01

    Piperazine compounds possess anti-infective, anti-carcinogenic, anxiolytic, hypotensive, anti-hypertensive and vasorelaxant properties and are attractive candidates for the development of new analgesic and anti-inflammatory drugs. This study investigates the anti-nociceptive and anti-inflammatory effects of piperazine derivative 4-[(1-phenyl-1H-pyrazol-4-yl) methyl]1-piperazine carboxylic acid ethyl ester (LQFM-008) and the involvement of the serotonergic pathway. In the formalin test, treatments with LQFM-008 (15 and 30mg/kg p.o.) reduced the licking time in both neurogenic and inflammatory phases of this test. In the tail flick and hot plate tests, LQFM008 treatment (15 and 30mg/kg p.o.) increased latency to thermal stimulus, suggesting the involvement of central mechanisms in the anti-nociceptive effect of LQFM-008. In the carrageenan-induced paw edema test, LQFM-008 (p.o.) at the doses of 15 and 30mg/kg reduced the edema at all tested time points, while the dose of 7.5mg/kg reduced the edema only for the first hour. LQFM-008 (30mg/kg p.o.) reduced both cell migration and protein exudation in the carrageenan-induced pleurisy test. Furthermore, pre-treatment with NAN-190 (0.6mg/kgi.p.) and PCPA (100mg/kgi.p.) antagonized the anti-nociceptive effect of LQFM-008 in both phases of the formalin test. Our data suggest that LQFM-008 possesses anti-inflammatory and anti-nociceptive effects mediated through the serotonergic pathway. PMID:26276732

  6. Comparative mutagenicity and genotoxicity of particles and aerosols emitted by the combustion of standard vs. rapeseed methyl ester supplemented bio-diesel fuels: impact of after treatment devices: oxidation catalyst and particulate filter.

    PubMed

    André, V; Barraud, C; Capron, D; Preterre, D; Keravec, V; Vendeville, C; Cazier, F; Pottier, D; Morin, J P; Sichel, F

    2015-01-01

    Diesel exhausts are partly responsible for the deleterious effects on human health associated with urban pollution, including cardiovascular diseases, asthma, COPD, and possibly lung cancer. Particulate fraction has been incriminated and thus largely investigated for its genotoxic properties, based on exposure conditions that are, however, not relevant for human risk assessment. In this paper, original and more realistic protocols were used to investigate the hazards induced by exhausts emitted by the combustion of standard (DF0) vs. bio-diesel fuels (DF7 and DF30) and to assess the impact of exhaust treatment devices (DOC and DPF). Mutagenicity and genotoxicity were evaluated for (1) resuspended particles ("off line" exposure that takes into account the bioavailability of adsorbed chemicals) and for (2) the whole aerosols (particles+gas phase components) under continuous flow exposure ("on line" exposure). Native particles displayed mutagenic properties associated with nitroaromatic profiles (YG1041), whereas PAHs did not seem to be involved. After DOC treatment, the mutagenicity of particles was fully abolished. In contrast, the level of particle deposition was low under continuous flow exposure, and the observed mutagenicity in TA98 and TA102 was thus attributable to the gas phase. A bactericidal effect was also observed in TA102 after DOC treatment, and a weak but significant mutagenicity persisted after DPF treatment for bio-diesel fuels. No formation of bulky DNA-adducts was observed on A549 cells exposed to diesel exhaust, even in very drastic conditions (organic extracts corresponding to 500 μg equivalent particule/mL, 48 h exposure). Taken together, these data indicate that the exhausts issued from the bio-diesel fuels supplemented with rapseed methyl ester (RME), and generated by current diesel engines equipped with after treatment devices are less mutagenic than older ones. The residual mutagenicity is linked to the gas phase and could be due to pro

  7. A novel approach for the characterization of a bilayer of phenyl-c71-butyric-acid-methyl ester and pentacene using ultraviolet photoemission spectroscopy and argon gas cluster ion beam sputtering process

    SciTech Connect

    Yun, Dong-Jin; Chung, JaeGwan; Jung, Changhoon; Chung, Yeonji; Kim, SeongHeon; Lee, Seunghyup; Kim, Ki-Hong; Han, Hyouksoo; Park, Gyeong-Su; Park, SungHoon

    2013-09-07

    The material arrangement and energy level alignment of an organic bilayer comprising of phenyl-c71-butyric-acid-methyl ester (PCBM-71) and pentacene were studied using ultraviolet photoelectron spectroscopy (UPS) and the argon gas cluster ion beam (GCIB) sputtering process. Although there is a small difference in the full width at half maximum of the carbon C 1s core level peaks and differences in the oxygen O 1s core levels of an X-ray photoemission spectroscopy spectra, these differences are insufficient to clearly distinguish between PCBM-71 and pentacene layers and to classify the interface and bulk regions. On the other hand, the valence band structures in the UPS spectra contain completely distinct configurations for the PCBM-71 and pentacene layers, even when they have similar atomic compositions. According to the valence band structures of the PCBM-71/pentacene/electrodes, the highest unoccupied molecular orbital (HOMO) region of pentacene is at least 0.8 eV closer to the Fermi level than that of PCBM-71 and it does not overlap with any of the chemical states in the valence band structure of PCBM-71. Therefore, by just following the variations in the area of the HOMO region of pentacene, the interface/bulk regions of the PCBM/pentacene layers were distinctly categorized. Besides, the variation of valence band structures as a function of the Ar GCIB sputtering time fully corroborated with the surface morphologies observed in the atomic force microscope images. In summary, we believe that the novel approach, which involves UPS analysis in conjunction with Ar GCIB sputtering, can be one of the best methods to characterize the material distribution and energy level alignments of stacks of organic layers.

  8. Purification and Characterization of a New Antifungal Compound 10-(2,2-dimethyl-cyclohexyl)-6,9-dihydroxy-4,9-dimethyl-dec-2-enoic Acid Methyl Ester from Streptomyces hydrogenans Strain DH16.

    PubMed

    Kaur, Talwinder; Kaur, Amarjeet; Sharma, Vishal; Manhas, Rajesh K

    2016-01-01

    In agriculture, biocontrol agents have been emerged as safe alternative to chemical pesticides where Streptomyces spp. and their metabolites constitute a great potential for their exploration as potent agents for controlling various fungal phytopathogens. The present study reports an antifungal compound purified from Streptomyces hydrogenans strain DH16, a soil isolate, using silica gel chromatography and semi preparative HPLC. The compound was characterized using various spectroscopic techniques (IR, (1)H and (13)C NMR) and named 10-(2,2-dimethyl-cyclohexyl)-6,9-dihydroxy-4,9-dimethyl-dec-2-enoic acid methyl ester (SH2). Compound (SH2) showed significant inhibitory activity against fungal phytopathogens and resulted in severe morphological aberrations in their structure. Minimal inhibitory and minimal fungicidal concentrations of the compound ranged from 6.25 to 25 μg/ml and 25 to 50 μg/ml, respectively. In vivo evaluation of the compound showed strong control efficacy against Alternaria brassicicola, a seed borne pathogen, on radish seeds. In comparison to mancozeb and carbendazim, the compound was more effective in controlling damping off disease. Additionally, it promoted plant growth with increased rate of seed germination, and displayed no phytotoxicity. The compound retained its antifungal activity after its exposure to temperature of 100°C and sunlight for 1 h. Furthermore, the compound (SH2) when tested for its biosafety was found to be non-cytotoxic, and non-mutagenic against Salmonella typhimurium TA98 and TA100 strains. This compound from S. hydrogenans strain DH16 has not been reported earlier, so this new compound can be developed as an ideal safe and superior biofungicide for the control of various fungal plant diseases. PMID:27446043

  9. Identifying dominant conformations of N-acetyl-L-cysteine methyl ester and N-acetyl-L-cysteine in water: VCD signatures of the amide I and the Cdbnd O stretching bands

    NASA Astrophysics Data System (ADS)

    Poopari, Mohammad Reza; Dezhahang, Zahra; Xu, Yunjie

    2015-02-01

    Infrared (IR) and vibrational circular dichroism (VCD) spectra of N-Acetyl-L-Cysteine Methyl Ester (NALCME) and N-Acetyl-L-Cysteine (NALC) in D2O under different pHs were measured. We focus on the VCD signatures of the amide I and the Cdbnd O stretching spectral signatures of the neutral NALCME and NALC species and the related ones of the deprotonated NALC species in the region of 1800-1500 cm-1. A sign inversion is observed for the amide I VCD band going from the neutral NALCME and NALC to the deprotonated NALC species. Density functional theory (DFT) calculations were carried out to search for the possible conformations of these three species and to simulate their IR and VCD spectra at the B3LYP/aug-cc-pVTZ level in the gas phase and with the polarization continuum model of water solvent. The most stable conformations found for neutral NALCME and NALC exhibit drastically difference VCD patterns, whereas those of deprotonated NALC show similar patterns. We establish an empirical structural-spectral relationship where the aforementioned VCD signatures can be used as spectral markers to identify dominant conformations of these two amino acid derivatives under different pHs. It is recognized that the dominant conformers identified using the VCD spectral markers differ from those based on the relative DFT energies for neutral NALCME and NALC. The influence of solvent on both the conformational geometries and their relative stabilities is discussed. The aforementioned discrepancy can be attributed to the explicit solute-solvent hydrogen-bonding interactions which are not accounted for in the calculations. The empirical structural-spectral relationship identified can potentially be applied to large, related amino acids and polypeptides in water.

  10. Purification and Characterization of a New Antifungal Compound 10-(2,2-dimethyl-cyclohexyl)-6,9-dihydroxy-4,9-dimethyl-dec-2-enoic Acid Methyl Ester from Streptomyces hydrogenans Strain DH16

    PubMed Central

    Kaur, Talwinder; Kaur, Amarjeet; Sharma, Vishal; Manhas, Rajesh K.

    2016-01-01

    In agriculture, biocontrol agents have been emerged as safe alternative to chemical pesticides where Streptomyces spp. and their metabolites constitute a great potential for their exploration as potent agents for controlling various fungal phytopathogens. The present study reports an antifungal compound purified from Streptomyces hydrogenans strain DH16, a soil isolate, using silica gel chromatography and semi preparative HPLC. The compound was characterized using various spectroscopic techniques (IR, 1H and 13C NMR) and named 10-(2,2-dimethyl-cyclohexyl)-6,9-dihydroxy-4,9-dimethyl-dec-2-enoic acid methyl ester (SH2). Compound (SH2) showed significant inhibitory activity against fungal phytopathogens and resulted in severe morphological aberrations in their structure. Minimal inhibitory and minimal fungicidal concentrations of the compound ranged from 6.25 to 25 μg/ml and 25 to 50 μg/ml, respectively. In vivo evaluation of the compound showed strong control efficacy against Alternaria brassicicola, a seed borne pathogen, on radish seeds. In comparison to mancozeb and carbendazim, the compound was more effective in controlling damping off disease. Additionally, it promoted plant growth with increased rate of seed germination, and displayed no phytotoxicity. The compound retained its antifungal activity after its exposure to temperature of 100°C and sunlight for 1 h. Furthermore, the compound (SH2) when tested for its biosafety was found to be non-cytotoxic, and non-mutagenic against Salmonella typhimurium TA98 and TA100 strains. This compound from S. hydrogenans strain DH16 has not been reported earlier, so this new compound can be developed as an ideal safe and superior biofungicide for the control of various fungal plant diseases. PMID:27446043

  11. Delineation of Stenotrophomonas maltophilia isolates from cystic fibrosis patients by fatty acid methyl ester profiles and matrix-assisted laser desorption/ionization time-of-flight mass spectra using hierarchical cluster analysis and principal component analysis.

    PubMed

    Vidigal, Pedrina Gonçalves; Mosel, Frank; Koehling, Hedda Luise; Mueller, Karl Dieter; Buer, Jan; Rath, Peter Michael; Steinmann, Joerg

    2014-12-01

    Stenotrophomonas maltophilia is an opportunist multidrug-resistant pathogen that causes a wide range of nosocomial infections. Various cystic fibrosis (CF) centres have reported an increasing prevalence of S. maltophilia colonization/infection among patients with this disease. The purpose of this study was to assess specific fingerprints of S. maltophilia isolates from CF patients (n = 71) by investigating fatty acid methyl esters (FAMEs) through gas chromatography (GC) and highly abundant proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and to compare them with isolates obtained from intensive care unit (ICU) patients (n = 20) and the environment (n = 11). Principal component analysis (PCA) of GC-FAME patterns did not reveal a clustering corresponding to distinct CF, ICU or environmental types. Based on the peak area index, it was observed that S. maltophilia isolates from CF patients produced significantly higher amounts of fatty acids in comparison with ICU patients and the environmental isolates. Hierarchical cluster analysis (HCA) based on the MALDI-TOF MS peak profiles of S. maltophilia revealed the presence of five large clusters, suggesting a high phenotypic diversity. Although HCA of MALDI-TOF mass spectra did not result in distinct clusters predominantly composed of CF isolates, PCA revealed the presence of a distinct cluster composed of S. maltophilia isolates from CF patients. Our data suggest that S. maltophilia colonizing CF patients tend to modify not only their fatty acid patterns but also their protein patterns as a response to adaptation in the unfavourable environment of the CF lung. PMID:25266870

  12. Role of nitric oxide in kidney and liver (as distance organ) function in bilateral renal ischemia-reperfusion: Effect of L-Arginine and NG-nitro-L-Arginine methyl ester

    PubMed Central

    Ghasemi, Mahmood; Nematbakhsh, Mehdi; Daneshmand, Fatemeh; Moeini, Maryam; Talebi, Ardeshir

    2015-01-01

    Background: Renal ischemia-reperfusion (RIR) is a major cause of renal dysfunction that acts through different mechanisms. We investigated the role of L-Arginine as an endogenous nitric oxide (NO) precursor and NG-nitro-L-Arginine methyl ester (L-NAME) as an NO inhibitor on kidney and liver function in RIR model. Materials and Methods: Fifty-eight Wistar rats were randomly assigned to four groups. Groups 1 (sham-operated, n = 13) received a single dose of saline (4 ml/kg, i.p.) and 2 (Ischemia [Isch], n = 14) received a single dose of saline (4 ml/kg, i.p.). Groups 3 (Isch + L-NAME, n = 15) received a single dose of L-NAME (20 mg/kg, i.p.) and 4 (Isch + L-Arginine n = 16) received a single dose of L-Arginine (300 mg/kg, i.p.), After 2 h, renal failure was induced by clamping both renal pedicles for 45 min, followed by 24-h reperfusion in Groups 2–4. Finally, blood samples were obtained, and kidney tissue samples were subjected for pathology investigations. Results: The body weight decreased, and the serum levels of blood urea nitrogen (BUN) and creatinine (Cr), and kidney tissue damage score (KTDS) increased significantly in the Isch and Isch + L-NAME groups compared with the sham group while L-Arginine improved weight reduction (P < 0.05), and it reduced the serum levels of BUN and Cr, and KTDS when compared with the Isch and Isch + L-NAME groups. Kidney weight increased significantly in all groups compared with the sham group. L-Arginine reduced the liver tissue level of malondialdehyde and increased alkaline phosphatase. Conclusion: L-Arginine as an NO precursor can improve kidney function against RIR. It also improves oxidative stress in liver tissue. PMID:26645018

  13. {2-[1-(3-Methoxycarbonylmethyl-1H-indol-2-yl)-1-methyl-ethyl]-1H-indol-3-yl}-acetic Acid Methyl Ester Inhibited Hepatocellular Carcinoma Growth in Bel-7402 Cells and Its Resistant Variants by Activation of NOX4 and SIRT3.

    PubMed

    Li, Ye; Wang, Wenjing; Xu, Xiaoxue; Sun, Shiyue; Xu, Xiaoyu; Qu, Xian-jun

    2015-01-01

    {2-[1-(3-Methoxycarbonylmethyl-1H-indol-2-yl)-1-methyl-ethyl]-1H-indol-3-yl}-acetic acid methyl ester (MIAM) is a novel indole compound, which possessed high efficacy against many cancers xenografted in mice without obvious toxicity. In this study, we aimed to investigate the effects of MIAM on human hepatocellular carcinoma (HCC) Bel-7402 cells and its resistant variants Bel-7402/5FU. MIAM inhibited the growth of HCC more potent in Bel-7402/5FU cells than its parent cells. MIAM increased cellular reactive oxygen species (ROS) levels, induced cell apoptosis, and arrested cell cycle in G0/G1 phase. MIAM might exert its action on Bel-7402/5FU cells through activation of NADPH oxidase 4 (NOX4)/p22(phox), Sirtuin3 (SIRT3)/SOD2, and SIRT3/p53/p21(Waf1/Cip) pathways. MIAM might inhibit HCC growth through the modulation of SIRT3. When SIRT3 was silenced, the inhibitory effect of MIAM on Bel-7402/5FU was lowered, showing the characteristic of resistance against MIAM, whereas Bel-7402/5FU cells with high expression of SIRT3 by SIRT3 adenovirus infection demonstrated the high sensitivity to MIAM. These results suggested that MIAM might exert its action against Bel-7402/5FU growth through upregulation of SIRT3. We suggested that MIAM might be a promising candidate compound which could develop as a potent anticancer agent targeting NOX4 and SIRT3 activation. PMID:25961022

  14. {2-[1-(3-Methoxycarbonylmethyl-1H-indol-2-yl)-1-methyl-ethyl]-1H-indol-3-yl}-acetic Acid Methyl Ester Inhibited Hepatocellular Carcinoma Growth in Bel-7402 Cells and Its Resistant Variants by Activation of NOX4 and SIRT3

    PubMed Central

    Li, Ye; Wang, Wenjing; Xu, Xiaoxue; Sun, Shiyue; Xu, Xiaoyu; Qu, Xian-jun

    2015-01-01

    {2-[1-(3-Methoxycarbonylmethyl-1H-indol-2-yl)-1-methyl-ethyl]-1H-indol-3-yl}-acetic acid methyl ester (MIAM) is a novel indole compound, which possessed high efficacy against many cancers xenografted in mice without obvious toxicity. In this study, we aimed to investigate the effects of MIAM on human hepatocellular carcinoma (HCC) Bel-7402 cells and its resistant variants Bel-7402/5FU. MIAM inhibited the growth of HCC more potent in Bel-7402/5FU cells than its parent cells. MIAM increased cellular reactive oxygen species (ROS) levels, induced cell apoptosis, and arrested cell cycle in G0/G1 phase. MIAM might exert its action on Bel-7402/5FU cells through activation of NADPH oxidase 4 (NOX4)/p22phox, Sirtuin3 (SIRT3)/SOD2, and SIRT3/p53/p21Waf1/Cip pathways. MIAM might inhibit HCC growth through the modulation of SIRT3. When SIRT3 was silenced, the inhibitory effect of MIAM on Bel-7402/5FU was lowered, showing the characteristic of resistance against MIAM, whereas Bel-7402/5FU cells with high expression of SIRT3 by SIRT3 adenovirus infection demonstrated the high sensitivity to MIAM. These results suggested that MIAM might exert its action against Bel-7402/5FU growth through upregulation of SIRT3. We suggested that MIAM might be a promising candidate compound which could develop as a potent anticancer agent targeting NOX4 and SIRT3 activation. PMID:25961022

  15. Changes in Esters of Fatty Acids of Rhizopus arrhizus During Germination and Growth

    PubMed Central

    Hess, S. L.; Weber, D. J.; Gunasekaran, M.

    1972-01-01

    Natural esters of fatty acids of Rhizopus arrhizus Fischer increased during the first 48 hr of growth. During the 48- to 72-hr period, there was a shift in concentration from the methyl esters to the ethyl esters of fatty acids. PMID:5079078

  16. Derivatives of iminomalonic ester

    SciTech Connect

    Prosyanik, A.V.; Fedoseenko, D.V.; Markov, V.I.

    1986-01-10

    The synthesis of (alkylimino)malonic esters was realized by the reaction of alkylamines with mesoxalic or dibromomalonic ester. (Halogenoimino)malonic esters were obtained for the first time by the reaction of aminomalonic ester with tert-butyl hypochlorite or sodium hypobromite. A new method was developed for the synthesis of (acylimino)malonic esters by the successive bromination and dehydrobromination of (acylamino)malonic esters. The addition of various nucleophiles (water, amines, formamide) at the C=N bond of (acylimino)malonic esters was studied.

  17. An Experimental and Kinetic Modeling Study of Methyl Decanoate Combustion

    SciTech Connect

    Sarathy, S M; Thomson, M J; Pitz, W J; Lu, T

    2009-12-04

    Biodiesel is a mixture of long chain fatty acid methyl esters derived from fats and oils. This research study presents opposed-flow diffusion flame data for one large fatty acid methyl ester, methyl decanoate, and uses the experiments to validate an improved skeletal mechanism consisting of 648 species and 2998 reactions. The results indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular weight oxygenated compounds such as carbon monoxide, formaldehyde, and ketene.

  18. Dimethyl fumarate and the oleanane triterpenoids, CDDO-imidazolide and CDDO-methyl ester, both activate the Nrf2 pathway but have opposite effects in the A/J model of lung carcinogenesis.

    PubMed

    To, Ciric; Ringelberg, Carol S; Royce, Darlene B; Williams, Charlotte R; Risingsong, Renee; Sporn, Michael B; Liby, Karen T

    2015-07-01

    Lung cancer accounts for the highest number of cancer-related deaths in the USA, highlighting the need for better prevention and therapy. Activation of the Nrf2 pathway detoxifies harmful insults and reduces oxidative stress, thus preventing carcinogenesis in various preclinical models. However, constitutive activation of the Nrf2 pathway has been detected in numerous cancers, which confers a survival advantage to tumor cells and a poor prognosis. In our study, we compared the effects of two clinically relevant classes of Nrf2 activators, dimethyl fumarate (DMF) and the synthetic oleanane triterpenoids, CDDO-imidazolide (CDDO-Im) and CDDO-methyl ester (CDDO-Me) in RAW 264.7 mouse macrophage-like cells, in VC1 lung cancer cells and in the A/J model of lung cancer. Although the triterpenoids and DMF both activated the Nrf2 pathway, CDDO-Im and CDDO-Me were markedly more potent than DMF. All of these drugs reduced the production of reactive oxygen species and inhibited nitric oxide production in RAW264.7 cells, but the triterpenoids were 100 times more potent than DMF in these assays. Microarray analysis revealed that only 52 of 99 Nrf2-target genes were induced by all three compounds, and each drug regulated a unique subset of Nrf2 genes. These drugs also altered the expression of other genes important in lung cancer independent of Nrf2. Although all three compounds enhanced the phosphorylation of CREB, only DMF increased the phosphorylation of Akt. CDDO-Me, at either 12.5 or 50mg/kg of diet, was the most effective drug in our lung cancer mouse model. Specifically, CDDO-Me significantly reduced the average tumor number, size and burden compared with the control group (P < 0.05). Additionally, 52% of the tumors in the control group were high-grade tumors compared with only 14% in the CDDO-Me group. Though less potent, CDDO-Im had similar activity as CDDO-Me. In contrast, 61-63% of the tumors in the DMF groups (400-1200mg/kg diet) were high-grade tumors compared with

  19. Duodenocutaneous fistula in rats as a model for "wound healing-therapy" in ulcer healing: the effect of pentadecapeptide BPC 157, L-nitro-arginine methyl ester and L-arginine.

    PubMed

    Skorjanec, S; Kokot, A; Drmic, D; Radic, B; Sever, M; Klicek, R; Kolenc, D; Zenko, A; Lovric Bencic, M; Belosic Halle, Z; Situm, A; Zivanovic Posilovic, G; Masnec, S; Suran, J; Aralica, G; Seiwerth, S; Sikiric, P

    2015-08-01

    While very rarely reported, duodenocutanenous fistula research might alter the duodenal ulcer disease background and therapy. Our research focused on rat duodenocutaneous fistulas, therapy, stable gastric pentadecapeptide BPC 157, an anti-ulcer peptide that healed other fistulas, nitric oxide synthase-substrate L-arginine, and nitric oxide synthase-inhibitor L-nitro-arginine methyl ester (L-NAME). The hypothesis was, duodenal ulcer-healing, like the skin ulcer, using the successful BPC 157, with nitric oxide-system involvement, the "wound healing-therapy", to heal the duodenal ulcer, the fistula-model that recently highlighted gastric and skin ulcer healing. Pressure in the lower esophageal and pyloric sphincters was simultaneously assessed. Duodenocutaneous fistula-rats received BPC 157 (10 μg/kg or 10 ng/kg, intraperitoneally or perorally (in drinking water)), L-NAME (5 mg/kg intraperitoneally), L-arginine (100 mg/kg intraperitoneally) alone and/or together, throughout 21 days. Duodenocutaneous fistula-rats maintained persistent defects, continuous fistula leakage, sphincter failure, mortality rate at 40% until the 4(th) day, all fully counteracted in all BPC 157-rats. The BPC 157-rats experienced rapidly improved complete presentation (maximal volume instilled already at 7(th) day). L-NAME further aggravated the duodenocutaneous fistula-course (mortality at 70% until the 4(th) day); L-arginine was beneficial (no mortality; however, maximal volume instilled not before 21(st) day). L-NAME-worsening was counteracted to the control level with the L-arginine effect, and vice versa, while BPC 157 annulled the L-NAME effects (L-NAME + L-arginine; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157 brought below the level of the control). It is likely that duodenocutaneous fistulas, duodenal/skin defect simultaneous healing, reinstated sphincter function, are a new nitric oxide-system related phenomenon. In conclusion, resolving the duodenocutanenous fistulashealing

  20. Crystallization behavior of fatty acid methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel made from vegetable oils or animal fats has many attractive characteristics as an alternative fuel for compression-ignition (diesel) engines. However, biodiesel from the most common agricultural sources has flow properties that are susceptible to start up and operability problems during c...

  1. Combustion analysis of esters of soybean oil in a diesel engine

    SciTech Connect

    Zhang, Y.; Van Gerpen, J.H.

    1996-09-01

    The alkyl esters of plant oils and animal fats are receiving increasing attention as renewable fuels for diesel engines. These esters have come to be known as biodiesel. One objection to the use of the methyl and ethyl esters of soybean oil as a fuel in diesel engines is their high crystallization temperature. One solution to this problem is to use the isopropyl esters of soybean oil which have significantly lower crystallization temperatures. Another method to improve the cold flow properties of esters is to winterize them to subambient temperature. This is accomplished by cooling the esters and filtering out the components that crystallize most readily. Previous work has shown that when methyl, isopropyl and winterized ester blends were compared with No. 2 diesel fuel, the isopropyl and winterized methyl esters had at least the same emission reduction potential as the methyl esters, with similar engine performance. This paper discusses those results using heat release analysis that shows all of the blends have shorter ignition delays, and lower premixed burn fractions than No. 2 diesel fuel. All tested fuels except the isopropyl ester blends had similar combustion behavior. However, blends with isopropyl ester showed some abnormal combustion behavior, possibly due to high levels of monoglycerides.

  2. Surface Tension Studies of Alkyl Esters and Epoxidized Alkyl Esters Relevant to Oleochemically Based Fuel Additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the surface tension of several epoxidized oleochemicals and their comparable fatty esters at temperatures between 25 and 60 deg C. Surface tensions of the olefins measured at 40 deg C range from 25.9 mN m-1, for isobutyl oleate, to 28.4 mN m-1 for methyl linoleate. The epoxy versions of ...

  3. Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate

    SciTech Connect

    Naik, C; Westbrook, C K; Herbinet, O; Pitz, W J; Mehl, M

    2010-01-22

    New chemical kinetic reaction mechanisms are developed for two of the five major components of biodiesel fuel, methyl stearate and methyl oleate. The mechanisms are produced using existing reaction classes and rules for reaction rates, with additional reaction classes to describe other reactions unique to methyl ester species. Mechanism capabilities were examined by computing fuel/air autoignition delay times and comparing the results with more conventional hydrocarbon fuels for which experimental results are available. Additional comparisons were carried out with measured results taken from jet-stirred reactor experiments for rapeseed methyl ester fuels. In both sets of computational tests, methyl oleate was found to be slightly less reactive than methyl stearate, and an explanation of this observation is made showing that the double bond in methyl oleate inhibits certain low temperature chain branching reaction pathways important in methyl stearate. The resulting detailed chemical kinetic reaction mechanism includes more approximately 3500 chemical species and more than 17,000 chemical reactions.

  4. (Accumulation of methyl-deficient rat liver messenger ribonucleic acid on ethionine administration). Progress report. [Methyltransferase activity in Ehrlich ascites tumor cells and effects of phorbol ester on methyltransferase activity

    SciTech Connect

    Borek, E.

    1980-01-01

    Enzyme fractions were isolated from Ehrlich ascites cells which introduced methyl groups into methyl deficient rat liver mRNA and unmethylated vaccinia mRNA. The methyl groups were incorporated at the 5' end into cap 1 structures by the viral enzyme, whereas both cap 0 and cap 1 structures were formed by the Ehrlich ascites cell enzymes. Preliminary results indicate the presence of adenine N/sup 6/-methyltransferase activity in Ehrlich ascites cells. These results indicate that mRNA deficient in 5'-cap methylation and in internal methylation of adenine accumulated in rats on exposure to ethionine. The methyl-deficient mRNA isolated from the liver of ethionine-fed rats differed in its translational properties from mRNA isolated from control animals. Preliminary experiments indicate that single topical application of 17n moles of TPA to mouse skin altered tRNA methyltransferases. The extent of methylation was increased over 2-fold in mouse skin treated with TPA for 48 hours. These changes have been observed as early as 12 hours following TPA treatment. In contrast, the application of initiating dose of DMBA had no effect on these enzymes. It should be emphasized that the changes in tRNA methyltransferases produced by TPA are not merely an increase of the concentration of the enzyme, rather that they represent alterations of specificity of a battery of enzymes. In turn the change in enzyme specificity can produce alterations in the structure of tRNA. (ERB)

  5. Choline Chloride Catalyzed Amidation of Fatty Acid Ester to Monoethanolamide: A Green Approach.

    PubMed

    Patil, Pramod; Pratap, Amit

    2016-01-01

    Choline chloride catalyzed efficient method for amidation of fatty acid methyl ester to monoethanolamide respectively. This is a solvent free, ecofriendly, 100% chemo selective and economically viable path for alkanolamide synthesis. The Kinetics of amidation of methyl ester were studied and found to be first order with respect to the concentration of ethanolamine. The activation energy (Ea) for the amidation of lauric acid methyl ester catalyzed by choline chloride was found to be 50.20 KJ mol(-1). The 98% conversion of lauric acid monoethanolamide was obtained at 110°C in 1 h with 6% weight of catalyst and 1:1.5 molar ratio of methyl ester to ethanolamine under nitrogen atmosphere. PMID:26666271

  6. PTR-MS study of esters in water and water/ethanol solutions

    NASA Astrophysics Data System (ADS)

    Aprea, Eugenio; Biasioli, Franco; Märk, Tilmann D.; Gasperi, Flavia

    2007-04-01

    Esters strongly influence the perceived aroma of alcoholic beverages and their rapid monitoring can play an important role in the quality control of these products. Proton transfer reaction mass spectrometry (PTR-MS) allows the rapid and non invasive monitoring of foodstuff but there is still a lack of information about the proton transfer induced fragmentation and on the effect of high ethanol concentration. PTR-MS fragmentation patterns of 21 esters are reported, most of them for the first time. For linear methyl and ethyl esters the fragmentation dependence on E/N was also evaluated. Acetate esters, with exception of methyl acetate, show as main peaks the characteristic fragment ions at m/z 61 and m/z 43, whereas propanoate esters, but methyl propanoate, exhibit as main peaks the typical signals at m/z 75 and m/z 57. For all the other esters, here reported, the spectra are dominated by the protonated molecular ion. For methyl and ethyl esters we also report, in many cases for the first time, the water-solution/air partition coefficients (Henry's law constant) and the ethanol-solution/air partition coefficients at different ethanol concentrations. The information provided in this work may be useful as a basis for further studies for the identification and quantification of esters in the headspace of alcoholic beverages extending the application field of PTR-MS.

  7. A Lactobacillus plantarum Esterase Active on a Broad Range of Phenolic Esters

    PubMed Central

    Esteban-Torres, María; Landete, José María; Reverón, Inés; Santamaría, Laura; de las Rivas, Blanca

    2015-01-01

    Lactobacillus plantarum is the lactic acid bacterial species most frequently found in the fermentation of food products of plant origin on which phenolic compounds are abundant. L. plantarum strains showed great flexibility in their ability to adapt to different environments and growth substrates. Of 28 L. plantarum strains analyzed, only cultures from 7 strains were able to hydrolyze hydroxycinnamic esters, such as methyl ferulate or methyl caffeate. As revealed by PCR, only these seven strains possessed the est_1092 gene. When the est_1092 gene was introduced into L. plantarum WCFS1 or L. lactis MG1363, their cultures acquired the ability to degrade hydroxycinnamic esters. These results support the suggestion that Est_1092 is the enzyme responsible for the degradation of hydroxycinnamic esters on the L. plantarum strains analyzed. The Est_1092 protein was recombinantly produced and biochemically characterized. Surprisingly, Est_1092 was able to hydrolyze not only hydroxycinnamic esters, since all the phenolic esters assayed were hydrolyzed. Quantitative PCR experiments revealed that the expression of est_1092 was induced in the presence of methyl ferulate, an hydroxycinnamic ester, but was inhibited on methyl gallate, an hydroxybenzoic ester. As Est_1092 is an enzyme active on a broad range of phenolic esters, simultaneously possessing feruloyl esterase and tannase activities, its presence on some L. plantarum strains provides them with additional advantages to survive and grow on plant environments. PMID:25746986

  8. A Lactobacillus plantarum esterase active on a broad range of phenolic esters.

    PubMed

    Esteban-Torres, María; Landete, José María; Reverón, Inés; Santamaría, Laura; de las Rivas, Blanca; Muñoz, Rosario

    2015-05-01

    Lactobacillus plantarum is the lactic acid bacterial species most frequently found in the fermentation of food products of plant origin on which phenolic compounds are abundant. L. plantarum strains showed great flexibility in their ability to adapt to different environments and growth substrates. Of 28 L. plantarum strains analyzed, only cultures from 7 strains were able to hydrolyze hydroxycinnamic esters, such as methyl ferulate or methyl caffeate. As revealed by PCR, only these seven strains possessed the est_1092 gene. When the est_1092 gene was introduced into L. plantarum WCFS1 or L. lactis MG1363, their cultures acquired the ability to degrade hydroxycinnamic esters. These results support the suggestion that Est_1092 is the enzyme responsible for the degradation of hydroxycinnamic esters on the L. plantarum strains analyzed. The Est_1092 protein was recombinantly produced and biochemically characterized. Surprisingly, Est_1092 was able to hydrolyze not only hydroxycinnamic esters, since all the phenolic esters assayed were hydrolyzed. Quantitative PCR experiments revealed that the expression of est_1092 was induced in the presence of methyl ferulate, an hydroxycinnamic ester, but was inhibited on methyl gallate, an hydroxybenzoic ester. As Est_1092 is an enzyme active on a broad range of phenolic esters, simultaneously possessing feruloyl esterase and tannase activities, its presence on some L. plantarum strains provides them with additional advantages to survive and grow on plant environments. PMID:25746986

  9. Synthesis and characterization of vegetable oil derived esters: evaluation for their diesel additive properties.

    PubMed

    Dmytryshyn, S L; Dalai, A K; Chaudhari, S T; Mishra, H K; Reaney, M J

    2004-03-01

    Trans-esterification of four vegetable oils; canola oil, greenseed canola oil from heat-damaged seeds, processed waste fryer grease and unprocessed waste fryer grease, was carried out using methanol, and KOH as catalyst. The methyl esters of the corresponding oils were separated from the crude glycerol, purified, and characterized by various methods to evaluate their densities, viscosities, iodine values, acid numbers, cloud points, pour points and gross heat of combustion, fatty acid and lipid compositions, lubricity properties, and thermal properties. The fatty acid composition suggests that 80-85% of the ester was from unsaturated acids. Substantial decrease in density and viscosity of the methyl esters compared to their corresponding oils suggested that the oils were in their mono or di glyceride form. The lubricity of the methyl esters, when blended at 1 vol% treat rate with ISOPAR M reference fuel, showed that the canola methyl ester enhanced the fuel's lubricity number. From the analyses performed, it was determined that the ester with the most potential for being an additive or a substitute for diesel fuel is the canola methyl ester, whose physical and chemical characteristics are similar to diesel fuel. PMID:14643986

  10. 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), ...

  11. 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...

  12. Comparative combustion studies on various plant oil esters and the long term effects of an ethyl ester on a compression ignition engine

    SciTech Connect

    Hawkins, C.S.; Fuls, J.

    1982-01-01

    Combustion studies on both ethyl and methyl esters of various plant oils were carried out using the same engine for all the tests so that comparative studies could be achieved. Twelve esters were tested and the pertinent data was recorded. Some of the more important results are published in this paper to serve as a comparative guide to the study of plant oil esters as fuel. Bruwer et. al. (1980) suggested the use of plant oil esters to prevent injector coking in modern compression ignition engines. Very little information is available on the long term effects of such ester use. Cyclic endurance tests have been carried out on Perkins engines running on ethyl esters of sunflower oil. The exciting results of this work are reported, with specific reference to one tractor engine which has recorded more than 1 300 trouble free hours. 3 tables.

  13. Synthesis and evaluation of oleic acid esters as dielectric liquids

    SciTech Connect

    Thomas, P.; Sridhar, S.; Krishnaswamy, K.R.

    1996-12-31

    The worldwide depletion of petroleum crude and the search for technologically and ecologically alternative to PCB`s has led to the development of synthetic liquid dielectric which are non-flammable, non-toxic and bio-degradable. Esters like Methyl oleate and Pentaerthritol tetra oleate were synthesized in the laboratory. These esters were evaluated for its Physical, Chemical, Electrical and Aging properties and the values obtained compare well with those of commercially available liquids like Midel 7131 and RTemp fluid. Further accelerated aging studies were performed on these esters and the data obtained reveal that the esters prepared in the laboratory has very good chemical stability towards oxidation without inhibitor when compared to Midel 7131 and RTemp fluid which have phenolic inhibitors.

  14. Ammonolysis of esters of hydroxybenzoic acids on a boron phosphate catalyst

    SciTech Connect

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

    1987-09-10

    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.

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

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.; Hsu, Victor

    1990-01-01

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

  16. Modeling of the oxidation of methyl esters—Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor

    PubMed Central

    Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

    2013-01-01

    The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes. PMID:23710076

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

    SciTech Connect

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

    1990-11-01

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

  18. Destruction of Leishmania mexicana amazonensis amastigotes within macrophages by lysosomotropic amino acid esters

    PubMed Central

    1986-01-01

    Leishmania amastigotes parasitize almost exclusively the mononuclear phagocytes of mammals. The organisms survive and multiply within acidified vacuoles (parasitophorous vacuoles; p.v.) akin to phagolysosomes. Certain amino acid esters are known to accumulate in and disrupt lysosomes. We postulated that, since Leishmania possess lysosome-like organelles, they may be susceptible to the potentially high ester concentrations attained in the p.v. We report here that L- amino acid esters can rapidly destroy intracellular Leishmania at concentrations that do not appear to damage the host cells. L-leu-OMe, which cured greater than or equal to 90% of infected macrophages at 0.8 mM concentrations, was used in most of the experiments. L-leu-OMe was only active after infection, implying inefficient transfer from secondary lysosomes to the p.v. Parasite destruction had several features in common with lysosomal and leukocyte damage induced by the esters, i.e., inactivity of D-amino acid esters, a marked pH dependence and increased killing after ester pulses at lower temperatures. Killing depended on the amino acid and on the ester substitution. The most active of the methyl esters assayed was that of leucine, followed by those of tryptophan, glutamic acid, methionine, phenylalanine, and tyrosine. Methyl esters of seven other amino acids were inactive when tested at up to 10 mM concentrations. Among leucine esters studied, benzyl ester was sixfold more active than the methyl homolog. The dipeptide L-leu-leu-OMe produced 90% cure at 0.08 mM concentrations. Leishmanicidal activity could be related to penetration of the parasites by the esters or to toxic ester hydrolysis products released in the p.v. The first hypothesis is supported by the pH-dependent destruction of isolated amastigotes by the esters. Furthermore, relatively high concentrations of L-leucine, methanol, or benzyl alcohol were not demonstrably toxic to the amastigotes. We postulate that ester concentrations

  19. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²- methyl]- 1,3-propanediyl] ester, polymer with 1,3-butadiene, ethenylbenzene and 2-hydroxyethyl 2-methyl-2-propenoate. 721.10122 Section 721.10122 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL...

  20. Identification of 9(E),11(E)-18:2 fatty acid methyl ester at trace level in thermal stressed olive oils by GC coupled to acetonitrile CI-MS and CI-MS/MS, a possible marker for adulteration by addition of deodorized olive oil.

    PubMed

    Saba, Alessandro; Mazzini, Francesco; Raffaelli, Andrea; Mattei, Alissa; Salvadori, Piero

    2005-06-15

    The olive oil market is suffering from sophisticated illegal treatments. One common adulteration process consists of the addition to virgin olive oil of lower quality oils, such as "lampante" oil, an inexpensive oil and with some organoleptic defects, which is then submitted to thermal deodorization under vacuum processes for removal of the undesired flavor components. Such a blending may not have a huge influence on the chemical composition and may not significantly affect the parameters usually checked as quality indicators, although the organoleptic properties may change. As a consequence, a major effort is being devoted to find reliable markers able to unmask such adulterations. We report here the complete characterization of a compound, detected at trace levels exclusively in thermal stressed oils, which could be a candidate marker for adulteration. The investigation, carried out by GC-MS and GC-MS/MS, provided its complete structure, including the stereochemistry, shown to be a 9(E),11(E)-18:2 fatty acid methyl ester. Experimental data also confirmed the influence of both temperature and heating time on formation and concentration of this compound. PMID:15941328

  1. meso-Ester Corroles.

    PubMed

    Canard, Gabriel; Gao, Di; D'Aléo, Anthony; Giorgi, Michel; Dang, Florian-Xuan; Balaban, Teodor Silviu

    2015-05-18

    The introduction of ester groups on the 5- and 15-meso positions of corroles stabilizes them against oxidation and induces a redshift of their absorption and emission spectra. These effects are studied through the photophysical and electrochemical characterization of up to 16 different 5,15-diester corroles, in which the third meso position is free or occupied by an aryl group, a long alkyl chain, or an ester moiety. Single-crystal X-ray structure analysis of five 5,15-diestercorroles and DFT and time-dependent DFT calculations show that the strong electron-withdrawing character of the 5,15 ester substituents is reinforced by their π overlap with the macrocyclic aromatic system. The crystal packing of corroles 2, 4, 6, 9, and 15 features short distances between chromophores that are stacked into columns thanks to the low steric hindrance of meso-ester groups. This close packing is partially due to intermolecular interactions that involve inner hydrogen and nitrogen atoms, and thereby, stabilize a single, identical corrole tautomeric form. PMID:25786789

  2. Bacteriopheophorbide esters: photosensitizers without "threshold dose"?

    NASA Astrophysics Data System (ADS)

    Moser, Joerg G.; Ostrowsky, Andreas; Guemuesdagli, Maria; Kleiber, Beate

    1994-03-01

    Uptake and phototoxicity of the methyl-, ethyl-, n-propyl, and 2-propyl esters of 132- hydroxy bacteriopheophorbide a were studied in OAT 75 SCLC cells and 3 different amelanotic melanoma cell lines. (A 375, Melur SP 18, SkAMel 25). Specific phototoxicity did not substantially differ for the different esters. Most surprisingly, these photosensitizers did not show any significant threshold behavior: even at 25 (mu) W/cm2 (775 nm, diode laser) cancer cell suspensions were killed in a time-dependent logarithmic fashion. Furthermore, phototoxicity is enhanced at low power densities if compared with the effects at 1 - 10 mW/cm2. This can be related only in part to a lack of oxygen at higher power densities. Complementary experiments confirmed that threshold is power but not dose dependent. Thus, threshold power density should be included into a prospective list of criteria characterizing photosensitizers suitable for photodynamic cancer therapy. The obvious lack of a limiting power density in bacteriopheophobide a esters make these sensitizers a prospective tool for tumor therapy in considerable tissue depth.

  3. Carbonation of epoxy methyl soyate at atmospheric pressure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbonated methyl soyates were prepared from epoxy methyl soyate by the introduction of carbon dioxide at the oxirane position. Carbonation was performed with carbon dioxide gas by sparging carbon dioxide through the epoxy esters at atmospheric pressure in the presence of tetrabutylammonium bromide...

  4. Attraction of the Parasitic Mite Varroa to the Drone Larvae of Honey Bees by Simple Aliphatic Esters

    NASA Astrophysics Data System (ADS)

    Le Conte, Yves; Arnold, Gerard; Trouiller, Jerome; Masson, Claudine; Chappe, Bertrand; Ourisson, Guy

    1989-08-01

    An important parasitic threat to honey bees, the mite Varroa jacobsoni, is attracted to its major prey, drone larvae, by methyl and ethyl esters of straight-chain fatty acids, in particular methyl palmitate. These esters were extracted from drone larvae with n-hexane and were identified by gas chromatography-mass spectrometry. Their behavioral effect was evaluated with the use of a four-arm airflow olfactometer.

  5. Behavioral and electrophysiological responses of Culex quinquefasciatus to certain fatty acid esters.

    PubMed

    Seenivasagan, Thangaraj; Guha, Lopamudra; Iqbal, S Thanvir

    2013-12-01

    Oviposition response of gravid Culex quinquefasciatus females to a series of synthetic fatty acid esters was evaluated at 10ppm under laboratory conditions. Octyl tridecanoate and propyl octadecanoate elicited 85% and 73% increased ovipositional responses respectively, compared to control, among the 16 esters tested. Other 14 esters showed highly significant repellency (67-96%) to gravid females. Standard 3-methyl indole received 69% increased egg deposition compared to control. In the Y-tube olfactometer, gravid C. quinquefasciatus females exhibited 78, 64% and 58% orientation respectively to octyl tridecanoate, propyl octadecanoate and 3-methyl indole. Gravid females exhibited 19-41% reduced orientation toward treatment odors of other esters significantly different from respective control. Electroantennogram studies revealed 4-18-fold increased antennal response, in which 3-methyl indole, octyl tridecanoate and propyl octadecanoate elicited 8-, 18- and 15-fold EAG response respectively, compared to control. Relative EAG response of octyl tridecanoate compared to standard 3-methyl indole was significantly different. Reduced EAG responses were elicited by FAE-06, -08, -13, -14 and -15, while the relative EAG responses of other esters were at par with the standard stimulus. These, esters could be utilized potentially as oviposition attractants and repellents against C. quinquefasciatus females to reduce the breeding in polluted water along with existing integrated vector control methods. PMID:24055543

  6. An Experimental and Kinetic Modeling Study of Methyl Decanoate Combustion

    SciTech Connect

    Sarathy, S M; Thomson, M J; Pitz, W J; Lu, T

    2010-02-19

    Biodiesel is typically a mixture of long chain fatty acid methyl esters for use in compression ignition engines. Improving biofuel engine performance requires understanding its fundamental combustion properties and the pathways of combustion. This research study presents new combustion data for methyl decanoate in an opposed-flow diffusion flame. An improved detailed chemical kinetic model for methyl decanoate combustion is developed, which serves as the basis for deriving a skeletal mechanism via the direct relation graph method. The novel skeletal mechanism consists of 648 species and 2998 reactions. This mechanism well predicts the methyl decanoate opposed-flow diffusion flame data. The results from the flame simulations indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular weight oxygenated compounds such as carbon monoxide, formaldehyde, and ketene.

  7. The ESTER project

    NASA Astrophysics Data System (ADS)

    Rieutord, M.; Dintrans, B.; Lignières, F.; Corbard, T.; Pichon, B.

    2005-12-01

    The ESTER project aims at building a stellar evolution code in two dimensions of space for the study of effects of rotation. The numerical scheme is based on spectral methods with a spherical harmonic decomposition in the horizontal direction and a Chebyshev polynomial expansion in the vertical direction. Coordinates adapted to the centrifugally distorted shape are mapped to spherical coordinates. First tests on rotating polytropes are presented.

  8. Composition of the wax fraction of bitumen from methylated brown coals

    SciTech Connect

    S.I. Zherebtsov; A.I. Moiseev

    2009-04-15

    Changes in the group and individual compositions of the wax fractions of bitumen in the course of brown coal methylation were studied. With the use of IR and NMR spectroscopy and chromatography-mass spectrometry, it was found that the esters of methylated coal waxes consisted of the native esters of fatty acids and the methyl esters of these acids formed as a result of an alkylation treatment. Esterification and transesterification were predominant among the reactions of aliphatic fraction components. A positive effect of methanol alkylation on an increase in the yield of the aliphatic fractions was found.

  9. Intermolecular reductive coupling of esters with benzophenones by low-valent titanium: synthesis of diarylmethyl ketones revisited.

    PubMed

    Kise, Naoki; Sakurai, Toshihiko

    2015-04-01

    The reductive coupling of aliphatic esters with benzophenones by Zn-TiCl4 in THF gave two- and four-electron reduced products, diaryl(hydroxy)methyl ketones, and diarylmethyl ketones selectively by controlling the reaction conditions. In the reaction of aromatic esters with benzophenones, diarylmethyl ketones were obtained as the sole products. N-(Alkoxycarbonyl)-(S)-α-amino acid methyl esters gave optically active diphenylmethyl ketones by reduction with benzophenone. The obtained diphenylmethyl ketones were transformed to 4,5-cis-disubstituted oxazolidin-2-ones stereoselectively. PMID:25748528

  10. Solvation of Esters and Ketones in Supercritical CO2.

    PubMed

    Kajiya, Daisuke; Imanishi, Masayoshi; Saitow, Ken-ichi

    2016-02-01

    Vibrational Raman spectra for the C═O stretching modes of three esters with different functional groups (methyl, a single phenyl, and two phenyl groups) were measured in supercritical carbon dioxide (scCO2). The results were compared with Raman spectra for three ketones involving the same functional groups, measured at the same thermodynamic states in scCO2. The peak frequencies of the Raman spectra of these six solute molecules were analyzed by decomposition into the attractive and repulsive energy components, based on the perturbed hard-sphere theory. For all solute molecules, the attractive energy is greater than the repulsive energy. In particular, a significant difference in the attractive energies of the ester-CO2 and ketone-CO2 systems was observed when the methyl group is attached to the ester or ketone. This difference was significantly reduced in the solute systems with a single phenyl group and was completely absent in those with two phenyl groups. The optimized structures among the solutes and CO2 molecules based on quantum chemical calculations indicate that greater attractive energy is obtained for a system where the oxygen atom of the ester is solvated by CO2 molecules. PMID:26741296

  11. Unexpected ring-closure products derived from 3-(2-allylanilino)-3-phenylacrylate esters: crystal and molecular structures of 3-acetyl-8-allyl-6-methyl-2-phenylquinolin-4-yl acetate and (2RS)-2,8-dimethyl-4-phenyl-1,2-dihydro-6H-pyrrolo[3,2,1-ij]quinolin-6-one.

    PubMed

    Luque, Adriana L; Sanabria, Carlos M; Palma, Alirio; Cobo, Justo; Glidewell, Christopher

    2016-08-01

    The reactions of two 3-(2-allylanilino)-3-phenylacrylate esters with acetic anhydride and with strong acids has revealed a richly diverse reactivity providing a number of unexpected products. Thus, acetylation of ethyl 3-(2-allylanilino)-3-phenylacrylate, (Ia), or ethyl 3-(2-allyl-4-methylanilino)-3-phenylacrylate, (Ib), with acetic anhydride yields not only the expected acetylated esters, (II), as the major products but also the unexpected polysubstituted quinolines 3-acetyl-8-allyl-2-phenylquinolin-4-yl acetate, (IIIa), and 3-acetyl-8-allyl-6-methyl-2-phenylquinolin-4-yl acetate, (IIIb), as minor products. Subsequent reaction of the major product ethyl 2-[(2-allyl-4-methylanilino)(phenyl)methylidene]-3-oxobutanoate, (IIb), with concentrated sulfuric acid did not provide the expected 3-acetylquinoline derivative, but instead two unexpected products, namely ethyl 4-ethyl-2-phenyl-1,4-dihydroquinoline-3-carboxylate, (IV), and ethyl 3-acetyl-4-ethyl-2-phenyl-3,4-dihydroquinoline-3-carboxylate, (V), in yields of 39 and 22%, respectively. The reaction of (Ib) with Eaton's reagent gave both the quinoline (Z)-6-methyl-2-phenyl-8-(prop-1-en-1-yl)quinolin-4(1H)-one, (VI), and the unexpected tricyclic product (2RS)-2,8-dimethyl-4-phenyl-1,2-dihydro-6H-pyrrolo[3,2,1-ij]quinolin-6-one, (VII), in yields of 71 and 12%, respectively. The products (II)-(VII) have all been fully characterized spectroscopically and the crystal structures of two of the unexpected products, i.e. (IIIb) (C23H21NO3) and (VII) (C19H17NO), are reported here. The formation of compounds (IV), (V) and (VII) all require an isomerization of the initial allyl substituent, with migration of the C=C double bond from the terminal site to the internal site. In (IIIb), the two acetyl substituents are oriented such that the intramolecular distance between the two carbonyl O atoms is only 3.243 (2) Å, and in (VII), the five-membered ring adopts a twisted half-chair conformation. The molecules of compound (IIIb

  12. Synthesis and characterization of novel dipeptide ester prodrugs of acyclovir

    NASA Astrophysics Data System (ADS)

    Nashed, Yasser E.; Mitra, Ashim K.

    2003-07-01

    Four dipeptide (Gly-Gly, Gly-Val, Val-Val, Val-Gly) ester prodrugs of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir, ACV) were synthesized. LC/MS was used to characterize the new prodrugs. Both 1H NMR and 13C NMR spectra of the four prodrugs of ACV were measured and assigned based on spectral comparison with compounds of similar structures.

  13. Role of the pks15/1 gene in the biosynthesis of phenolglycolipids in the Mycobacterium tuberculosis complex. Evidence that all strains synthesize glycosylated p-hydroxybenzoic methyl esters and that strains devoid of phenolglycolipids harbor a frameshift mutation in the pks15/1 gene.

    PubMed

    Constant, Patricia; Perez, Esther; Malaga, Wladimir; Lanéelle, Marie-Antoinette; Saurel, Olivier; Daffé, Mamadou; Guilhot, Christophe

    2002-10-11

    Diesters of phthiocerol and phenolphthiocerol are important virulence factors of Mycobacterium tuberculosis and Mycobacterium leprae, the two main mycobacterial pathogens in humans. They are both long-chain beta-diols, and their biosynthetic pathway is beginning to be elucidated. Although the two classes of molecules share a common lipid core, phthiocerol diesters have been found in all the strains of the M. tuberculosis complex examined although phenolphthiocerol diesters are produced by only a few groups of strains. To address the question of the origin of this diversity 8 reference strains and 10 clinical isolates of M. tuberculosis were analyzed. We report the presence of glycosylated p-hydroxybenzoic acid methyl esters, structurally related to the type-specific phenolphthiocerol glycolipids, in the culture media of all reference strains of M. tuberculosis, suggesting that the strains devoid of phenolphthiocerol derivatives are unable to elongate the putative p-hydroxybenzoic acid precursor. We also show that all the strains of M. tuberculosis examined and deficient in the production of phenolphthiocerol derivatives are natural mutants with a frameshift mutation in pks15/1 whereas a single open reading frame for pks15/1 is found in Mycobacterium bovis BCG, M. leprae, and strains of M. tuberculosis that produce phenolphthiocerol derivatives. Complementation of the H37Rv strain of M. tuberculosis, which is devoid of phenolphthiocerol derivatives, with the fused pks15/1 gene from M. bovis BCG restored phenolphthiocerol glycolipids production. Conversely, disruption of the pks15/1 gene in M. bovis BCG led to the abolition of the synthesis of type-specific phenolphthiocerol glycolipid. These data indicate that Pks15/1 is involved in the elongation of p-hydroxybenzoic acid to give p-hydroxyphenylalkanoates, which in turn are converted, presumably by the PpsA-E synthase, to phenolphthiocerol derivatives. PMID:12138124

  14. The preferential nNOS inhibitor 7-nitroindazole and the non-selective one N(G)-nitro-L-arginine methyl ester administered alone or jointly with L-DOPA differentially affect motor behavior and monoamine metabolism in sham-operated and 6-OHDA-lesioned rats.

    PubMed

    Czarnecka, Anna; Konieczny, Jolanta; Lenda, Tomasz; Lorenc-Koci, Elżbieta

    2015-11-01

    Reciprocal interactions between nitrergic and dopaminergic systems play a key role in the control of motor behavior. In the present study, we performed a comparative analysis of motor behavior (locomotor activity, catalepsy, rotational behavior) and monoamine metabolism in the striatum and substantia nigra of unilaterally sham-operated and 6-OHDA-lesioned rats treated with the preferential neuronal nitric oxide synthase (nNOS) inhibitor 7-nitroindazole (7-NI) or the non-selective one N(G)-nitro-L-arginine methyl ester (L-NAME), alone or in combination with L-DOPA. Each NOS inhibitor given alone (50mg/kg) induced a distinct catalepsy 30 min after injection but only 7-NI impaired spontaneous locomotion after 10 min. In 6-OHDA-lesioned rats, chronic L-DOPA (25mg/kg) induced 2.5-h long contralateral rotations. 7-NI (30 and 50mg/kg) markedly reduced the intensity of L-DOPA-induced contralateral rotations while extending their duration until 4.5h whereas L-NAME (50 and 100mg/kg) only tended to attenuate their intensity without affecting the duration. 7-NI but not L-NAME significantly increased endogenous tissue DA levels in the nigrostriatal system of both sham-operated and 6-OHDA-lesioned rats. In L-DOPA-treated group, 7-NI significantly enhanced the L-DOPA-derived tissue DA content in this system and decreased the level of the intracellular DA metabolite DOPAC produced by monoamine oxidase (MAO). In contrast to 7-NI, L-NAME decreased markedly DA content and did not affect DOPAC level in the ipsilateral striatum. It means that the differences in 7-NI and L-NAME-mediated modulation of L-DOPA-induced behavioral and biochemical effects resulted not only from the inhibition of NOS activity but also from differences in their ability to inhibit MAO. PMID:26319690

  15. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

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

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

    SciTech Connect

    Zhang, Yu.; Yang, Yi; Boehman, Andre L.

    2009-06-15

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

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

    NASA Astrophysics Data System (ADS)

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

    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.

  18. Development of a Method for the N-Arylation of Amino Acid Esters with Aryl Triflates.

    PubMed

    King, Sandra M; Buchwald, Stephen L

    2016-08-19

    A general method for the N-arylation of amino acid esters with aryl triflates is described. Both α- and β-amino acid esters, including methyl, tert-butyl, and benzyl esters, are viable substrates. Reaction optimization was carried out by design of experiment (DOE) analysis using JMP software. The mild reaction conditions, which use t-BuBrettPhos Pd G3 or G4 precatalyst, result in minimal racemization of the amino acid ester. This method is the first synthetic application of the t-BuBrettPhos Pd G4 precatalyst. Mechanistic studies show that the observed erosion in enantiomeric excess is due to racemization of the amino acid ester starting material and not of the product. PMID:27498618

  19. Lewis acid catalysis of photochemical reactions. 5. Selective isomerization of conjugated butenoic and dienoic esters

    SciTech Connect

    Lewis, F.D.; Howard, D.K.; Barancyk, S.V.; Oxman, J.D.

    1986-05-28

    The effects of Lewis and Broensted acids upon the photoisomerization reactions of several conjugated butenoic and dienoic esters have been investigated. Lewis acids inhibit the photochemical deconjugation of ..cap alpha..,..beta..- to ..beta..,..gamma..-unsaturated butenoic esters and shift the photoequilibrium between E and Z isomers toward the Z isomer. As such, irradiation of E ..cap alpha..,..beta..-unsaturated esters in the presence of EtAlCl/sub 2/ provides a convenient method for the preparation of the thermodynamically less stable Z isomer. Irradiation of methyl (E,E)-2,4-hexadienoate and methyl (E,E)-5-phenyl-2,4-pentadienoate in the absence of added catalysts results in nonselective E,Z isomerization to give mixtures of all four stereoisomers in roughly comparable yields. In the presence of the Broensted acid trifluoroacetic acid, quantitative conversion of methyl 2,4-hexadienoates to methyl 3,4-hexadienoate is observed. The acid serves as a catalyst for the thermal 1,3-hydrogen shift of an allenic enol ester formed via a photochemical 1,5-hydrogen shift of the conjugated esters. Irradiation of the ground-state complexes of the conjugated esters with the Lewis acids EtAlCl/sub 2/ or BF/sub 3/ results in selective E,Z isomerization about the ..cap alpha..,..beta..-double bond in methyl 2,4-hexadienoate and the ..gamma..,delta-double bond in methyl 5-phenyl-24-pentadienoate. The mechanistic bases for the observed effects of Lewis acids are selective excitation of the more strongly absorbing E complex and more efficient isomerization of the excited E vs. Z complex.

  20. Synthesis and preliminary characterisation of new esters of the bacterial polysaccharide gellan.

    PubMed

    Crescenzi, V; Dentini, M; Segatori, M; Tiblandi, C; Callegaro, L; Benedetti, L

    1992-07-01

    Under the appropriate experimental conditions, ethyl, propyl, and methylprednisolon-21-yl esters of gellan can be obtained without significant degradation. At low degrees of esterification (de), depending on the ester moiety, the products are water-soluble, which allows the influence of hydrophilicity and charge density on their ability to assume an ordered conformation in dilute aqueous solution to be studied. With high de, the products were soluble only in organic solvents (e.g., methyl sulphoxide) with good film-forming capacity. The methylprednisolon-21-yl esters have been characterised in a preliminary manner in terms of drug-release kinetics. PMID:1394330

  1. Antiallergic activity of rosmarinic acid esters is modulated by hydrophobicity, and bulkiness of alkyl side chain.

    PubMed

    Zhu, Fengxian; Xu, Zhongming; Yonekura, Lina; Yang, Ronghua; Tamura, Hirotoshi

    2015-01-01

    Methyl, propyl and hexyl esters of rosmarinic, caffeic and p-coumaric acids were tested for antiallergic activity, and rosmarinic acid propyl ester exhibited the greatest β-hexosaminidase release suppression (IC50, 23.7 μM). Quadratic correlations between pIC50 and cLogP (r(2) = 0.94, 0.98, and 1.00, respectively) were observed in each acid ester series. The antiallergic activity is modulated by hydrophobicity, and alkyl chain bulkiness. PMID:25686361

  2. Methyl Iodide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl iodide (MeI, iodomethane, CH3I) was reported as a potential alternative to the stratospheric ozone-depleting fumigant methyl bromide (MeBr) in the mid-1990s (Sims et al., 1995; Ohr et al., 1996). It has since received significant research attention to determine its environmental fate and tran...

  3. Methyl chloroform

    SciTech Connect

    Wray, T.K.

    1994-04-01

    Methyl chloroform is identified as a Class 1 ozone-depleting substance under Title VI of the CAA Amendments. On Nov. 30, 1993, EPA ordered the phaseout of Class 1 ozone-depleting substances -- chlorofluorocarbons (CFCs), halons, carbon tetrachloride and methyl chloroform -- by Jan. 1, 1996. Methyl chloroform and other Class 1 substances may be used after the dead-line if sources can be found through recycling or existing inventories. Methyl chloroform is listed as a hazardous air pollutant under CAA. It also is a SARA Title III, Sec. 313 compound with a reportable quantity of 1,000 pounds. OSHA and the American Conference of Government Industrial Hygienists have set 350 ppm as the time-weighted average airborne exposure level for methyl chloroform. NIOSH lists its immediately dangerous to life or health'' concentration as 1,000 parts per million. DOT identifies the substance as a hazardous material, Class 6.1 (poison).

  4. VvMJE1 of the grapevine (Vitis vinifera) VvMES Methylesterase family encodes for Methyl Jasmonate Esterase and has a role in stress response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The known members of the plant methyl esterase (MES) family catalyze hydrolysis of a C-O ester linkage of methyl esters of several phytohormones including indole-3-acetic acid, salicylic acid, and jasmonic acid. The genome of grapevine (Vitis vinifera) was found to contain 15 MES genes, designated V...

  5. VvMJE1 of the grapevine (Vitis vinifera) VvMES methylesterase family encodes for methyl jasmonate esterase and has a role in stress response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The known members of the plant methyl esterase (MES) family catalyze hydrolysis of a C-O ester linkage of methyl esters of several phytohormones including indole-3-acetic acid, salicylic acid, and jasmonic acid. The genome of grapevine (Vitis vinifera) was found to contain 15 MES genes, designated V...

  6. AVOIDING PITFALLS IN THE DETERMINATION OF HALOCARBOXYLIC ACIDS: THE PHOTOCHEMISTRY OF METHYLATION

    EPA Science Inventory

    Haloethanoic (haloacetic) acids are formed during chlorination of drinking water and are regulated by the Environmental Protection Agency (EPA). These compounds are normally quantified by gas chromatography with electron capture detection (GC-ECD) ad the methyl esters. EPA Meth...

  7. Lipoate ester multifunctional lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven lipoate esters were synthesized by esterification of lipoic acid with different structures of alcohols in the presence of a solid acid catalyst and without solvent. The esters were obtained in good yield, characterized using 1H NMR and GPC; and their physical properties investigated. Four of t...

  8. Synthesis of pyromellitic acid esters

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  9. [Enantioseparation of 2-phenylcarboxylic acid esters by capillary gas chromatography].

    PubMed

    Shi, Xueyan; Liu, Feipeng; Bian, Qinghua

    2016-01-01

    Chiral 2-arylcarboxylic acid derivatives are important intermediates for preparing 2-arylcarboxylic acids, which are non-steroidal anti-inflammatory drugs (NSAIDs). In order to separate 2-phenylcarboxylic acid ester enantiomers by capillary gas chromatography (CGC), 2, 6-di-O-pentyl-3-O-butyryl-β-cyclodextrin and 2,6-di-O-benzyl-3-O-heptanoyl-β-cyclodextrin were used as CGC chiral stationary phases, separately, and their enantioseparation abilities to enantiomers of methyl 2-phenylbutanoate, ethyl 2-phenylbutanoate, isopropyl 2-phenylbutanoate, methyl 2-phenylpropionate and cyclopentyl 2-phenylpropionate were examined. It was found that methyl 2-phenylbutanoate, methyl 2-phenylpropionate and cyclopentyl 2-phenylpropionate were successfully separated by using 2,6-di-O-pentyl-3-O-butyryl-β-cyclodextrin and 2,6-di-O-benzyl-3-O-heptanoyl-β-cyclodextrin as CGC chiral stationary phases, respectively. The enantiomer separation abilities of 2, 6-di-O-pentyl-3-O-butyryl-β-cyclodextrin to the three pairs of 2-phenylcarboxylic acid esters tested are superior to those of 2, 6-di-O-benzyl-3-O-heptanoyl-β-cyclodextrin. PMID:27319170

  10. Conversion of methyl oleate to branched-chain hydroxy fatty acid derivatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a project to develop new and expanded uses of oilseed products and by-products (such as biodiesel, fuel additives, and lubricants), studies were conducted on the synthetic conversion of oleic acid (in ester form) to branched-chain fatty acid ester derivatives. In these studies, methyl ol...

  11. New lipophilic tyrosyl esters. Comparative antioxidant evaluation with hydroxytyrosyl esters.

    PubMed

    Mateos, Raquel; Trujillo, Mariana; Pereira-Caro, Gema; Madrona, Andrés; Cert, Arturo; Espartero, José Luis

    2008-11-26

    New lipophilic esters of tyrosol, a naturally occurring phenol with interesting biological properties, have been synthesized in good yields by a chemoselective procedure, using lipase from Candida antarctica or p-toluenesulfonic acid as catalysts. Their antioxidant activities have been evaluated by the Rancimat test in lipophilic food matrices, as well as by FRAP and ABTS assays in methanolic solutions, and compared with those of previously synthesized hydroxytyrosyl esters. Free tyrosol, hydroxytyrosol, butylhydroxytoluene, and alpha-tocopherol were used as standards. All methods used for the antioxidant activity evaluation emphasized the high influence of the ortho-diphenolic structure on the antioxidant capacity, tyrosol and its derivatives being less active than hydroxytyrosol and its analogues and even less than BHT and alpha-tocopherol. In addition, the Rancimat test revealed a lower activity for ester derivatives than for their respective reference compounds (HTy or Ty), in agreement with the polar paradox. On the other hand, FRAP and ABTS methods reported an opposite behavior between the synthetic esters and their respective references. Thus, hydroxytyrosyl esters were more active than HTy, whereas tyrosyl esters were less active than Ty. The length and nature of the acyl side chain did not seem to play an important role in the antioxidant activity of either the hydroxytyrosyl or tyrosyl ester series, since no significant differences were observed among them. PMID:18983160

  12. Potential grape-derived contributions to volatile ester concentrations in wine.

    PubMed

    Boss, Paul K; Pearce, Anthony D; Zhao, Yanjia; Nicholson, Emily L; Dennis, Eric G; Jeffery, David W

    2015-01-01

    Grape composition affects wine flavour and aroma not only through varietal compounds, but also by influencing the production of volatile compounds by yeast. C9 and C12 compounds that potentially influence ethyl ester synthesis during fermentation were studied using a model grape juice medium. It was shown that the addition of free fatty acids, their methyl esters or acyl-carnitine and acyl-amino acid conjugates can increase ethyl ester production in fermentations. The stimulation of ethyl ester production above that of the control was apparent when lower concentrations of the C9 compounds were added to the model musts compared to the C12 compounds. Four amino acids, which are involved in CoA biosynthesis, were also added to model grape juice medium in the absence of pantothenate to test their ability to influence ethyl and acetate ester production. β-Alanine was the only one shown to increase the production of ethyl esters, free fatty acids and acetate esters. The addition of 1 mg∙L(-1) β-alanine was enough to stimulate production of these compounds and addition of up to 100 mg∙L(-1) β-alanine had no greater effect. The endogenous concentrations of β-alanine in fifty Cabernet Sauvignon grape samples exceeded the 1 mg∙L(-1) required for the stimulatory effect on ethyl and acetate ester production observed in this study. PMID:25939071

  13. Fatty acid alkyl esters as solvents: An evaluation of the kauri-butanol value. Comparison to hydrocarbons, dimethyl diesters and other oxygenates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Esters, most commonly methyl esters, of vegetable oils or animal fats or other lipid feedstocks have found increasing use as an alternative diesel fuel known as biodiesel. However, biodiesel also has good solvent properties, a feature rendered additionally attractive by its biodegradability, low tox...

  14. Lubricant properties of ester hydroxy derivatives of methyl oleate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The advantages of vegetable oil based products are their eco-friendly and non-toxic nature. The disadvantages of vegetable oils, such as poor oxidation and low temperature properties, can be improved by attaching functional groups at the sites of unsaturation through chemical modifications. In thi...

  15. Phenolic analogues of diastereoisomeric 2-methyl reversed esters of pethidine.

    PubMed

    Casy, A F; Dewar, G H; Pascoe, R A

    1989-03-01

    The preparation and stereochemical characterization of alpha- and beta-isomers of 1,2-dimethyl-4-m-hydroxyphenyl-4-propionyloxypiperidine are described. Both the alpha (axial 4-aryl/chair) and beta (equatorial 4-aryl/chair) isomers were of low potency or inactive in mice antinociceptive tests. Shortcomings of the alpha-isomer as a model for the 4-arylpiperidine moiety of morphine are discussed. PMID:2568454

  16. Evaluation of Partially Hydrogenated Methyl Esters of Soybean Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Specifications mandating biodiesel quality, most notably in the EU (EN 14214) and the USA (ASTM D 6751), have emerged that influence feedstock choice in the production of biodiesel fuel. For instance, EN 14214 contains a specification for iodine value (IV, 120) that eliminates soybean oil (SBO) as ...

  17. Nitrogen Derivatives of Soybean Oil and Fatty Acid Methyl Esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable oil based products are eco-friendly and non-toxic in nature, which is increasing their utilization in lot of applications. The presence of double bonds in some of the fatty acids, are attractive sites for functionalization. In this study we have used these sites for functionalization usi...

  18. Lubrication fluids from branched fatty acid methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have invented a new method for the synthesis of lubrication fluids using natural vegetable oils. Ordinary vegetable oils are good lubricants, but in their native form, they lack the stability necessary for many applications. Materials made using this new technology display significantly increas...

  19. Application of Ester based Drilling Fluid for Shale Gas Drilling

    NASA Astrophysics Data System (ADS)

    Sauki, Arina; Safwan Zazarli Shah, Mohamad; Bakar, Wan Zairani Wan

    2015-05-01

    Water based mud is the most commonly used mud in drilling operation. However, it is ineffective when dealing with water-sensitive shale that can lead to shale hydration, consequently wellbore instability is compromised. The alternative way to deal with this kind of shale is using synthetic-based mud (SBM) or oil-based mud (OBM). OBM is the best option in terms of technical requirement. Nevertheless, it is toxic and will create environmental problems when it is discharged to onshore or offshore environment. SBM is safer than the OBM. The aim of this research is to formulate a drilling mud system that can carry out its essential functions for shale gas drilling to avoid borehole instability. Ester based SBM has been chosen for the mud formulation. The ester used is methyl-ester C12-C14 derived from palm oil. The best formulation of ester-based drilling fluid was selected by manipulating the oil-water ratio content in the mud which are 70/30, 80/20 and 90/10 respectively. The feasibility of using this mud for shale gas drilling was investigated by measuring the rheological properties, shale reactivity and toxicity of the mud and the results were compared with a few types of OBM and WBM. The best rheological performance can be seen at 80/20 oil-water ratio of ester based mud. The findings revealed that the rheological performance of ester based mud is comparable with the excellent performance of sarapar based OBM and about 80% better than the WBM in terms of fluid loss. Apart from that, it is less toxic than other types of OBM which can maintain 60% prawn's survival even after 96 hours exposure in 100,000 ppm of mud concentration in artificial seawater.

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

    EPA Science Inventory

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

  1. Studies of a pyridino-crown ether-based chiral stationary phase on the enantioseparation of biogenic chiral aralkylamines and α-amino acid esters by high-performance liquid chromatography.

    PubMed

    Lévai, Sándor; Németh, Tamás; Fődi, Tamás; Kupai, József; Tóth, Tünde; Huszthy, Péter; Balogh, György Tibor

    2015-11-10

    This paper reports the enantioseparation ability of a pyridino-18-crown-6 ether-based chiral stationary phase [(S,S)-CSP-1]. The enantiomeric discrimination of chiral stationary phase (S,S)-CSP-1 was evaluated by HPLC using the mixtures of enantiomers of various protonated primary aralkylamines [1-phenylethylamine hydrogen perchlorate (PEA), 2,3-dihydro-1H-inden-1-amine (1-aminoindan), 2,2'-(1,2-diaminoethane-1,2-diyl) diphenol (HPEN)] and perchlorate salts of α-amino acid esters [alanine benzyl ester (Ala-OBn), phenylalanine benzyl ester (Phe-OBn), phenylalanine methyl ester (Phe-OMe), phenylglycine methyl ester (PhGly-OMe), glutamic acid dibenzyl ester (Glu-diOBn), and valine benzyl ester (Val-OBn)]. The best enantioseparation was achieved in the case of PEA. The high enantioselectivity was rationalized by the strong π-π interaction of the extended π system of the aryl-substituted pyridine unit. PMID:26218505

  2. DNA Methylation

    PubMed Central

    Marinus, M.G.; Løbner-Olesen, A.

    2014-01-01

    The DNA of E. coli contains 19,120 6-methyladenines and 12,045 5-methylcytosines in addition to the four regular bases and these are formed by the postreplicative action of three DNA methyltransferases. The majority of the methylated bases are formed by the Dam and Dcm methyltransferases encoded by the dam (DNA adenine methyltransferase) and dcm (DNA cytosine methyltransferase) genes. Although not essential, Dam methylation is important for strand discrimination during repair of replication errors, controlling the frequency of initiation of chromosome replication at oriC, and regulation of transcription initiation at promoters containing GATC sequences. In contrast, there is no known function for Dcm methylation although Dcm recognition sites constitute sequence motifs for Very Short Patch repair of T/G base mismatches. In certain bacteria (e.g., Vibrio cholerae, Caulobacter crescentus) adenine methylation is essential and in C. crescentus, it is important for temporal gene expression which, in turn, is required for coordinating chromosome initiation, replication and division. In practical terms, Dam and Dcm methylation can inhibit restriction enzyme cleavage; decrease transformation frequency in certain bacteria; decrease the stability of short direct repeats; are necessary for site-directed mutagenesis; and to probe eukaryotic structure and function. PMID:26442938

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Impact of fatty ester composition on low temperature properties of biodiesel-petroleum diesel blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several biodiesel fuels along with neat fatty acid methyl esters (FAMEs) commonly encountered in biodiesel were blended with ultra-low sulfur diesel (ULSD) fuel at low blend levels permitted by ASTM D975 (B1-B5) and cold flow properties such as cloud point (CP), cold filter plugging point (CFPP), an...

  5. Acrylic esters in radiation polymerization

    SciTech Connect

    Fomina, N.V.; Khoromskaya, V.A.; Shiryaeva, G.V.

    1988-03-01

    The radiation behavior of (meth)acrylic esters of varying structure was studied. It was shown that in radiation polymerization, in contrast to thermal polymerization, the structure of the ester part can significantly affect the reaction rate and capacity for polymerization in the presence of oxygen. The experimental data are explained from the point of view of consideration of nonvalence effects of the substitutent on the reactivity of the double bond.

  6. Integrated reactive absorption process for synthesis of fatty esters.

    PubMed

    Kiss, Anton Alexandru; Bildea, Costin Sorin

    2011-01-01

    Reactive separations using green catalysts offer great opportunities for manufacturing fatty esters, involved in specialty chemicals and biodiesel production. Integrating reaction and separation into one unit provides key benefits such as: simplified operation, no waste, reduced capital investment and low operating costs. This work presents a novel heat-integrated reactive absorption process that eliminates all conventional catalyst related operations, efficiently uses the raw materials and equipment, and considerably reduces the energy requirements for biodiesel production--85% lower as compared to the base case. Rigorous simulations based on experimental results were carried out using Aspen Plus and Dynamics. Despite the high degree of integration, the process is well controllable using an efficient control structure proposed in this work. The main results are provided for a plant producing 10 ktpy fatty acid methyl esters from methanol and waste vegetable oil with high free fatty acids content, using sulfated zirconia as solid acid catalyst. PMID:20855198

  7. Fatty esters from vegetable oils for use as a diesel fuel

    SciTech Connect

    Freedman, B.; Pryde, E.H.

    1982-01-01

    Transesterification of sunflower and soybean oils to fatty esters has been carried out to study reaction variables such as: (1) molar ratio of alcohol to vegetable oil, (2) alcohol type (methanol, ethanol, and 1-butanol), (3) catalyst type (alkaline and acidic), and (4) reaction temperature (60/sup 0/, 45/sup 0/, and 32/sup 0/C). These studies showed that ester formation was 90 to 98% complete at the respective molar ratios of methanol/sunflower oil of 4:1 and 6:1. All three alcohols produced high yields of esters. Alkaline catalysts were much more effective than acid catalysts. At both 45/sup 0/ and 60/sup 0/, 97% of methyl esters were produced in 1 hr. 5 figures.

  8. Optimized Carbonate and Ester-Based Li-Ion Electrolytes

    NASA Technical Reports Server (NTRS)

    Smart, Marshall; Bugga, Ratnakumar

    2008-01-01

    To maintain high conductivity in low temperatures, electrolyte co-solvents have been designed to have a high dielectric constant, low viscosity, adequate coordination behavior, and appropriate liquid ranges and salt solubilities. Electrolytes that contain ester-based co-solvents in large proportion (greater than 50 percent) and ethylene carbonate (EC) in small proportion (less than 20 percent) improve low-temperature performance in MCMB carbon-LiNiCoO2 lithium-ion cells. These co-solvents have been demonstrated to enhance performance, especially at temperatures down to 70 C. Low-viscosity, ester-based co-solvents were incorporated into multi-component electrolytes of the following composition: 1.0 M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (1:1:8 volume percent) [where X = methyl butyrate (MB), ethyl butyrate EB, methyl propionate (MP), or ethyl valerate (EV)]. These electrolyte formulations result in improved low-temperature performance of lithium-ion cells, with dramatic results at temperatures below 40 C.

  9. Methyl chloride

    Integrated Risk Information System (IRIS)

    Methyl chloride ; CASRN 74 - 87 - 3 ( 07 / 17 / 2001 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  10. Methyl acrylate

    Integrated Risk Information System (IRIS)

    Methyl acrylate ; CASRN 96 - 33 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  11. Methyl isocyanate

    Integrated Risk Information System (IRIS)

    Methyl isocyanate ; CASRN 624 - 83 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  12. Methyl iodide

    Integrated Risk Information System (IRIS)

    Methyl iodide ; CASRN 74 - 88 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effe

  13. Methyl parathion

    Integrated Risk Information System (IRIS)

    Methyl parathion ; CASRN 298 - 00 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  14. Methyl chlorocarbonate

    Integrated Risk Information System (IRIS)

    Methyl chlorocarbonate ; CASRN 79 - 22 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  15. Methyl methacrylate

    Integrated Risk Information System (IRIS)

    Methyl methacrylate ; CASRN 80 - 62 - 6 ( 03 / 02 / 98 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments f

  16. FTIR studies of hydrogen bonding between α,β-unsaturated esters and alcohols

    NASA Astrophysics Data System (ADS)

    Tonge, P. J.; Fausto, R.; Carey, P. R.

    1996-06-01

    The enthalpy (and entropy) of hydrogen bond formation has been measured between the ester carbonyl groups of the two α,β-unsaturated esters thienylacryloyl (TAOMe) and 5-methylthienylacryloyl (5MeTAOMe) methyl ester and the hydrogen bond donors ethanol, phenol and 3,5-dichlorophenol in CCl 4. For the esters, the hydrogen bonding strengths were measured by quantitating the amount of bound and unbound donor, using the OH stretching region, as a function of temperature and applying the van't Hoff equation. The decrease in νCO of the ester carbonyl group upon hydrogen bond formation ΔνCO has also been measured and correlated with the enthalpy of hydrogen bond formation. A linear correlation is observed between the enthalpy of hydrogen bond formation - ΔH and ΔνCO, with - ΔH = 1.36 ΔνCO - 16.1, where ΔH is measured in kJ mol -1 and Δν in cm -1. Comparison with data for other carbonyl acceptor compounds indicates that the carbonyl group of the above α,β-unsaturated esters is more readily polarized than the carbonyl group of saturated esters or ketones. The quantitative relationship between - ΔH and ΔνCO derived here has been used to determine the change in the enthalpy of hydrogen bond formation between substrate and enzyme groups in a series of acylserine proteases.

  17. Analysis of alcohols, as dimethylglycine esters, by electrospray ionization tandem mass spectrometry.

    PubMed

    Johnson, D W

    2001-03-01

    Dimethylglycine (DMG) esters are new derivatives for the rapid, sensitive and selective analysis of primary and secondary alcohols, in complex mixtures, by electrospray ionization tandem mass spectrometry (ESI-MS/MS). Their development was inspired by the use of the complementary dimethylaminoethyl esters for the trace, rapid analysis of fatty acids. DMG esters are simply prepared by heating a dichloromethane solution of the imidazolide of dimethylglycine, containing triethylamine, and an alcohol. DMG esters of long-chain fatty alcohols, isoprenoidal alcohols and hydroxy-acids are analysed by electrospray ionization tandem mass spectrometry with a precursor ion of m/z 104 scan. Diols, glyceryl esters, glyceryl ethers and some sterols are analysed by a neutral loss of 103 Da scan. Trimethylglycine (TMG) ester iodides, prepared by alkylation of DMG esters with methyl iodide, are more sensitive derivatives for molecules containing secondary alcohol groups, such as cholesterol and gibberellic acid. They are analysed by a precursor ion of m/z 118 scan. DMG or TMG derivatives were shown to be at least comparable and sometimes an order of magnitude more sensitive than N-methylpyridyl ether derivatives for ESI-MS/MS analysis of the different classes of alcohols. Applications of these derivatives for the diagnosis of inherited disorders and the analysis of natural products are presented. PMID:11312519

  18. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    PubMed

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. PMID:23313636

  19. 40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide, fluthiacet-methyl, acetic acid thiadiazolo pyridazin-1-ylidene)amino]phenyl]thio...-methyland its acid metabolite: acetic acid, thiadiazolo pyridazin-1-ylidene)amino]phenyl]thio]-methyl ester, and its acid metabolite, acetic acid, thiadiazolo pyridazin-1-ylidene)amino]phenyl]thio]- , in or...

  20. 40 CFR 180.551 - Fluthiacet-methyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide, fluthiacet-methyl, acetic acid thiadiazolo pyridazin-1-ylidene)amino]phenyl]thio...-methyland its acid metabolite: acetic acid, thiadiazolo pyridazin-1-ylidene)amino]phenyl]thio]-methyl ester, and its acid metabolite, acetic acid, thiadiazolo pyridazin-1-ylidene)amino]phenyl]thio]- , in or...

  1. EFFECT OF METHYL PARATHION ON FOOD DISCRIMINATION IN NORTHERN BOBWHITE (COLINUS VIRGINIANUS)

    EPA Science Inventory

    The effect of methyl parathion on dietary discrimination ability was assessed in two-week-old northern bobwhite (Colinus virginianus). n initial oral dose of methyl parathion(O, 3 or 6 mg/kg: 0, 0-dimethyl 0-(4-nitrophenyl-ester) was given to two subgroups of bobwhite before a 6-...

  2. Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

    PubMed

    Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

    2015-12-01

    Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future. PMID:26138876

  3. Fiberite 954: cyanate ester systems

    NASA Astrophysics Data System (ADS)

    Almen, G. R.; Mackenzie, P. D.; Malhotra, Vinay; Maskell, R. K.

    1992-09-01

    Cost and weight savings achieved by the use of composites have allowed these materials to displace their metal counterparts in space applications. Epoxy matrix based carbon fiber reinforced composites, such as Fiberite 934, have been used for a number of years. Relative to these systems, cyanate esters offer a number of unique attributes such as excellent hydrophobicity and electrical properties, reduced residual stress and better microcrack resistance, and improved radiation resistance. The significant reduction in water sorption and the low response to uptake make it possible to achieve much improved dimensional stability and reduced outgassing. These features may be used to advantage in electro-optical applications in space. ICI Fiberite has developed cyanate ester based prepreg systems that are penetrating the satellite, military radome and structural aerospace markets. Features of these systems will be presented and the properties of the cyanate ester based prepreg, Fiberite 954- 3, will be compared to those of Fiberite 934.

  4. Nematicidal activity of natural ester compounds and their analogues against pine wood nematode, Bursaphelenchus xylophilus.

    PubMed

    Seo, Seon-Mi; Kim, Junheon; Koh, Sang-Hyun; Ahn, Young-Joon; Park, Il-Kwon

    2014-09-17

    In this study, we evaluated the nematicidal activity of natural ester compounds against the pine wood nematode, Bursaphelenchus xylophilus, to identify candidates for the development of novel, safe nematicides. We also tested the nematicidal activity of synthesized analogues of these ester compounds to determine the structure-activity relationship. Among 28 ester compounds tested, isobutyl 2-methylbutanoate, 3-methylbutyl 2-methylbutanoate, 3-methylbutyl tiglate, 3-methyl-2-butenyl 2-methylbutanoate, and pentyl 2-methylbutanoate showed strong nematicidal activity against the pine wood nematode at a 1 mg/mL concentration. The other ester compounds showed weak nematicidal activity. The LC50 values of 3-methylbutyl tiglate, isobutyl 2-methylbutanoate, 3-methylbutyl 2-methylbutanoate, 3-methyl-2-butenyl 2-methylbutanoate, and pentyl 2-methylbutanoate were 0.0218, 0.0284, 0.0326, 0.0402, and 0.0480 mg/mL, respectively. The ester compounds described herein merit further study as potential nematicides for pine wood nematode control. PMID:25153339

  5. Measurement of pectin methylation in plant cell walls

    SciTech Connect

    McFeeters, R.F.; Armstrong, S.A.

    1984-01-01

    A procedure was developed to measure the degree of pectin methylation in small samples of isolated cell walls from nonlignified plant tissues or pectin solutions. Galacturonic acid was determined colorimetrically with the 3,5-dimethylphenol reagent. Methylation was measured by base hydrolysis of galacturonic acid methyl esters, followed by gas chromatographic determination of released methanol. Estimates of the precision of analysis of pectin and cell wall samples were made. The coefficient of variation for estimates of the pectin esterification in cell walls isolated from 10-g samples of cucumber tissue ranged from 7.7 to 13.2%.

  6. Synthesis and Utility of Dihydropyridine Boronic Esters.

    PubMed

    Panda, Santanu; Coffin, Aaron; Nguyen, Q Nhu; Tantillo, Dean J; Ready, Joseph M

    2016-02-01

    When activated by an acylating agent, pyridine boronic esters react with organometallic reagents to form a dihydropyridine boronic ester. This intermediate allows access to a number of valuable substituted pyridine, dihydropyridine, and piperidine products. PMID:26694785

  7. Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

    2009-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.

  8. Synthesis of Chiral, Enantiopure Allylic Amines by the Julia Olefination of α-Amino Esters.

    PubMed

    Benedetti, Fabio; Berti, Federico; Fanfoni, Lidia; Garbo, Michele; Regini, Giorgia; Felluga, Fulvia

    2016-01-01

    The four-step conversion of a series of N-Boc-protected l-amino acid methyl esters into enantiopure N-Boc allylamines by a modified Julia olefination is described. Key steps include the reaction of a lithiated phenylalkylsulfone with amino esters, giving chiral β-ketosulfones, and the reductive elimination of related α-acetoxysulfones. The overall transformation takes place under mild conditions, with good yields, and without loss of stereochemical integrity, being in this respect superior to the conventional Julia reaction of α-amino aldehydes. PMID:27338326

  9. Reductive Etherification of Fatty Acids or Esters with Alcohols using Molecular Hydrogen.

    PubMed

    Erb, Benjamin; Risto, Eugen; Wendling, Timo; Gooßen, Lukas J

    2016-06-22

    In the presence of a catalyst system consisting of a ruthenium/triphos complex and the Brønsted acid trifluoromethanesulfonimide, mixtures of fatty acids and aliphatic alcohols are converted into the corresponding ethers at 70 bar H2 . The protocol allows the sustainable one-step synthesis of valuable long-chain ether fragrances, lubricants, and surfactants from renewable sources. The reaction protocol is extended to various fatty acids and esters both in pure form and as mixtures, for example, tall oil acids or rapeseed methyl ester (RME). Even the mixed triglyceride rapeseed oil was converted in one step. PMID:27214823

  10. Origin of Kinetic Resolution of Hydroxy Esters through Catalytic Enantioselective Lactonization by Chiral Phosphoric Acids.

    PubMed

    Changotra, Avtar; Sunoj, Raghavan B

    2016-08-01

    Kinetic resolution is a widely used strategy for separation and enrichment of enantiomers. Using density functional theory computations, the origin of how a chiral BINOL-phosphoric acid catalyzes the selective lactonization of one of the enantiomers of α-methyl γ-hydroxy ester is identified. In a stepwise mechanism, the stereocontrolling transition state for the addition of the hydroxyl group to the si face of the ester carbonyl in the case of the S isomer exhibits a network of more effective noncovalent interactions between the substrate and the chiral catalyst. PMID:27463593

  11. REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

    EPA Science Inventory

    Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

  12. Trimerization of Phenyl Cyanate Ester

    NASA Astrophysics Data System (ADS)

    Pallaka, Madhusudhan Reddy; Simon, Sindee L.

    2015-03-01

    The kinetics of phenyl cyanate ester trimerization is studied in the bulk using differential scanning calorimetry. Dynamic experiments for different heating rates are analyzed for the activation energy using the model-free Kissinger-Akahira-Sunose(KAS) isoconversion method. The activation energy and other kinetic parameters are also obtained by fitting the dynamic data to a first order autocatalytic reaction model, which well describes the experimental data. The activation energy obtained from the KAS isoconversion method (70.1 kJ/mol) is in good agreement with that obtained from the kinetic model (73.2 kJ/mol) and is much lower than the more bulky cyanate esters studied in our laboratory, which have activation energies of approximately 95 kJ/mol. In addition, the rate constant for the phenyl cyanate ester is one to two orders higher than the bulkier cyanate esters in the temperature range of 200 to 300°C. Further elucidation of the dynamic experiments revealed a strong dependence of the reaction kinetics on the sample weight. Future work aims to understand this finding.

  13. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  14. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Methylamine esters. 721.3034 Section... Substances § 721.3034 Methylamine esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as methylamine esters (PMN P-94-982) is...

  15. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methylamine esters. 721.3034 Section... Substances § 721.3034 Methylamine esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as methylamine esters (PMN P-94-982) is...

  16. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  17. Methyl gallate.

    PubMed

    Bebout, Deborah; Pagola, Silvina

    2009-01-01

    THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: methyl 3,4,5-trihydroxy-benzoate), C(8)H(8)O(5), is composed of essentially planar mol-ecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10) Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intra-molecular hydrogen bonds, each mol-ecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network. PMID:21581923

  18. Methyl gallate

    PubMed Central

    Bebout, Deborah; Pagola, Silvina

    2009-01-01

    The crystal structure of the title compound (systematic name: methyl 3,4,5-trihydroxy­benzoate), C8H8O5, is composed of essentially planar mol­ecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10) Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intra­molecular hydrogen bonds, each mol­ecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network. PMID:21581923

  19. Lipase-catalyzed (trans)esterification of 5-hydroxy- methylfurfural and separation from HMF esters using deep-eutectic solvents.

    PubMed

    Krystof, Monika; Pérez-Sánchez, María; Domínguez de María, Pablo

    2013-04-01

    5-Hydroxymethylfurfural (HMF) is a valuable biomass-derived building block. Among possible HMF valorization products, a broad range of HMF esters can be synthesized. These HMF esters have found some promising applications, such as monomers, fuels, additives, surfactants, and fungicides, and thus several catalytic approaches for HMF (trans)esterifications have been reported. The intrinsic reactivity of HMF is challenging, forcing the use of mild reaction conditions to avoid by-product formation. This paper explores the lipase-catalyzed (trans)esterification of HMF with different acyl donors (carboxylic acids and methyl- and ethyl esters) mostly in solvent-free conditions. The results demonstrate that lipases may be promising alternatives for the synthesis of HMF esters-with high productivities and reactions at high substrate loadings-provided that robust systems for lipase immobilization are applied to assure an adequate reusability of the enzymes. Once (trans)esterifications have been conducted, the separation of unreacted HMF and HMF esters is performed by using deep-eutectic solvents (DES) as separation agents. DES are able to dissolve hydrogen-bond donors (e.g., HMF), whereas non-hydrogen-bond donors (in this case HMF esters) form a second phase. By using this approach, high ester purities (>99 %) and efficiencies (up to >90 % HMF ester recovery) in separations were obtained by using choline chloride-based DES. PMID:23456887

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

    PubMed

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

    2012-01-01

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

  1. The Rotational Spectrum and Conformational Structures of Methyl Valerate

    NASA Astrophysics Data System (ADS)

    Nguyen, Ha Vinh Lam; Stahl, Wolfgang

    2015-06-01

    Methyl valerate, C4H9COOCH3, belongs to the class of fruit esters, which play an important role in nature as odorants of different fruits, flowers, and wines. A sufficient explanation for the structure-odor relation of is not available. It is known that predicting the odor of a substance is not possible by knowing only its chemical formula. A typical example is the blueberry- or pine apple-like odor of ethyl isovalerate while its isomers ethyl valerate and isoamyl acetate smell like green apple and banana, respectively. Obviously, not only the composition but also the molecular structures are not negligible by determining the odor of a substance. Gas phase structures of fruit esters are thus important for a first step towards the determination of structure-odor relation since the sense of smell starts from gas phase molecules. For this purpose, a combination of microwave spectroscopy and quantum chemical calculations (QCCs) is an excellent tool. Small esters often have sufficient vapor pressure to be transferred easily in the gas phase for a rotational study but already contain a large number of atoms which makes them too big for classical structure determination by isotopic substitution and requires nowadays a comparison with the structures optimized by QCCs. On the other hand, the results from QCCs have to be validated by the experimental values. About the internal dynamics, the methoxy methyl group -COOCH3 of methyl acetate shows internal rotation with a barrier of 424.581(56) wn. A similar barrier height of 429.324(23) wn was found in methyl propionate, where the acetyl group is extended to the propionyl group. The investigation on methyl valerate fits well in this series of methyl alkynoates. In this talk, the structure of the most energetic favorable conformer as well as the internal rotation shown by the methoxy methyl group will be reported. It could be confirmed that the internal rotation barrier of the methoxy methyl group remains by longer alkyl chain.

  2. Fuel properties of methyl esters of borage and black currant oils containing methyl-gamma-linolenate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Additional or alternative feedstocks are one of the major areas of interest regarding biodiesel. In this work, two oils enriched in gamma-linolenic acid (6Z,9Z,12Z-octadecatrienoic acid) were investigated as biodiesel feedstocks. One oil is black currant in which gamma-linolenic and alpha-linolenic ...

  3. Apple volatiles synergize the response of codling moth to pear ester.

    PubMed

    El-Sayed, Ashraf M; Cole, Lyn; Revell, John; Manning, Lee-Anne; Twidle, Andrew; Knight, Alan L; Bus, Vincent G M; Suckling, David M

    2013-05-01

    Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), is a major cosmopolitan pest of apple and other pome fruits. Ethyl (E,Z)-2,4-decadienoate (pear ester) has been identified as a host-derived kairomone for female and male codling moths. However, pear ester has not performed similarly in different fruit production areas in terms of the relative magnitude of moth catch, especially the proportion of females caught. Our work was undertaken to identify host volatiles from apples, and to investigate whether these volatiles can be used to enhance the efficacy of host kairomone pear ester for monitoring female and male codling moths. Volatiles from immature apple trees were collected in the field using dynamic headspace sampling during the active period of codling moth flight. Using gas chromatography-electroantennogram detector (GC/EAD) analysis, six compounds elicited responses from antennae of females. These compounds were identified by GC/mass spectrometry (MS) and comparisons to authentic standards as nonanal, (E)-4,8-dimethyl-1,3,7-nonatriene, methyl salicylate, decanal, (Z,E)-α-farnesene, and (E,E)-α-farnesene. When the EAD-active compounds were tested individually in the field, no codling moths were caught except for a single male with decanal. However, addition of (E)-4,8-dimethyl-1,3,7-nonatriene, methyl salicylate, decanal, or (E,E)-α-farnesene to pear ester in a binary mixture enhanced the efficacy of pear ester for attracting female codling moths compared to pear ester alone. Addition of the 6-component blend to the pear ester resulted in a significant increase in the number of males attracted, and enhanced the females captured compared to pear ester alone; the number of males and females caught was similar to that with the pear ester plus acetic acid combination lure. Our results demonstrate that it is possible to synergize the response of codling moth to host kairomone by using other host volatiles. The new apple-pear ester host kairomone blend

  4. Gamma-aminobutyric acid esters. 1. Synthesis, brain uptake, and pharmacological studies of aliphatic and steroid esters of gamma-aminobutyric acid

    SciTech Connect

    Shashoua, V.E.; Jacob, J.N.; Ridge, R.; Campbell, A.; Baldessarini, R.J.

    1984-05-01

    Labeled and unlabeled aliphatic and steroid esters of gamma-amino(U-/sup 14/C)butyric acid (GABA) were synthesized and tested for their capacity to penetrate the blood-brain barrier and for evidence of central neuropharmacological activity in rodents. The uptake of the labeled 9,12,15-octadecatrienyl (linolenyl), 3-cholesteryl, 1-butyl, and the 9-fluoro-11 beta,17-dihydroxy-16 alpha-methyl-3,20-dioxopregna -1,4-dien-21-yl (dexamethasone) esters of GABA into mouse brain increased 2-, 25-, 74-, and 81-fold over GABA, respectively. The cholesteryl ester of GABA depressed the general motor activity of mice and rats in a dose-dependent manner, whereas the 1-butyl, linolenyl, and dexamethasone esters were inactive by this test. Studies of the rates of hydrolysis, GABA receptor binding capacity, and octanol/water partition coefficients indicated that pharmacological activity of the esters after entry into the central nervous system (CNS) was dependent on their capacity to release GABA by enzymatic hydrolysis and their lipid solubility.

  5. Structure, function and carcinogenicity of metabolites of methylated and non-methylated polycyclic aromatic hydrocarbons: a comprehensive review.

    PubMed

    Flesher, James W; Lehner, Andreas F

    2016-01-01

    The Unified Theory of PAH Carcinogenicity accommodates the activities of methylated and non-methylated polycyclic aromatic hydrocarbons (PAHs) and states that substitution of methyl groups on meso-methyl substituted PAHs with hydroxy, acetoxy, chloride, bromide or sulfuric acid ester groups imparts potent cancer producing properties. It incorporates specific predictions from past researchers on the mechanism of carcinogenesis by methyl-substituted hydrocarbons, including (1) requirement for metabolism to an ArCH2X type structure where X is a good leaving group and (2) biological substitution of a meso-methyl group at the most reactive center in non-methylated hydrocarbons. The Theory incorporates strong inferences of Fieser: (1) The mechanism of carcinogenesis involves a specific metabolic substitution of a hydrocarbon at its most reactive center and (2) Metabolic elimination of a carcinogen is a detoxifying process competitive with that of carcinogenesis and occurring by a different mechanism. According to this outlook, chemical or biochemical substitution of a methyl group at the reactive meso-position of non-methylated hydrocarbons is the first step in the mechanism of carcinogenesis for most, if not all, PAHs and the most potent metabolites of PAHs are to be found among the meso methyl-substituted hydrocarbons. Some PAHs and their known or potential metabolites and closely related compounds have been tested in rats for production of sarcomas at the site of subcutaneous injection and the results strongly support the specific predictions of the Unified Theory. PMID:26894797

  6. Evaluation of Alkyl Esters from Camelina Sativa Oil as Biodiesel and as Blend Components in Ultra Low Sulfur Diesel Fuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl and ethyl esters were prepared from camelina [Camelina sativa (L.) Crantz] oil by homogenous base-catalyzed transesterification for evaluation as a potential alternative source of biodiesel fuel. Camelina oil contained a high percentage of linolenic (32.6 wt %), linoleic (19.6 wt %), and ole...

  7. Synthesis of ethers by GaBr3 -catalyzed reduction of carboxylic acid esters and lactones by siloxanes.

    PubMed

    Biermann, Ursula; Metzger, Jürgen O

    2014-02-01

    Ethers were synthesized by reduction of the respective esters catalyzed by gallium bromide (GaBr3 ) and using siloxanes, preferentially 1,1,3,3-tetramethyldisiloxane, as reductant. Methyl oleate, triglycerides, that is, tributyrine and glyceryl triundec-10-enoate as well as γ- and δ-lactones were converted into the respective ethers in high to moderate yields. γ-Lactones were reduced with high selectivity in the presence of a methyl ester functionality. The reduction has been carried out at room temperature or moderately elevated temperature of up to 60 °C using stoichiometric amounts of the reductant and 0.005-0.01 equiv of GaBr3 as catalyst per ester functionality without any solvent added. After a reaction time of 1-4 h the conversion of the substrate was 100 %. The product was separated from polymeric siloxanes formed as coupled product by simple distillation. PMID:24488681

  8. Enantiospecific Alkynylation of Alkylboronic Esters

    PubMed Central

    Wang, Yahui; Noble, Adam; Myers, Eddie L.

    2016-01-01

    Abstract Enantioenriched secondary and tertiary alkyl pinacolboronic esters undergo enantiospecific deborylative alkynylation through a Zweifel‐type alkenylation followed by a 1,2‐elimination reaction. The process involves use of α‐lithio vinyl bromide or vinyl carbamate species, for which application to Zweifel‐type reactions has not previously been explored. The resulting functionalized 1,1‐disubstituted alkenes undergo facile base‐mediated elimination to generate terminal alkyne products in high yield and excellent levels of enantiospecificity over a wide range of pinacolboronic ester substrates. Furthermore, along with terminal alkynes, internal and silyl‐protected alkynes can be formed by simply introducing a suitable carbon‐ or silicon‐based electrophile after the base‐mediated 1,2‐elimination reaction. PMID:26934427

  9. ESTER: Evolution STEllaire en Rotation

    NASA Astrophysics Data System (ADS)

    Rieutord, Michel

    2013-05-01

    The ESTER code computes the steady state of an isolated star of mass larger than two solar masses. The only convective region computed as such is the core where isentropy is assumed. ESTER provides solutions of the partial differential equations, for the pressure, density, temperature, angular velocity and meridional velocity for the whole volume. The angular velocity (differential rotation) and meridional circulation are computed consistently with the structure and are driven by the baroclinic torque. The code uses spectral methods, both radially and horizontally, with spherical harmonics and Chebyshev polynomials. The iterations follow Newton's algorithm. The code is object-oriented and is written in C++; a python suite allows an easy visualization of the results. While running, PGPLOT graphs are displayed to show evolution of the iterations.

  10. Segmented polyether-ester copolymers

    SciTech Connect

    Souffie, R.D.

    1982-08-01

    This article touches on the chemistry of manufacture and structure of thermoplastic elastomers. The physical properties and environmental resistance characteristics of these copolymers are related to their molecular makeup. Results indicate that segmented polyether esters, because of their basic chemical structure, are resistant to a wide range of oils, solvents and chemicals. They are also highly elastic, resilient polymers which can be both cost and performance effective when used in a number of industrial applications.

  11. Methods of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-08-03

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

  12. Variables affecting the yields of fatty esters from transesterified vegetable oils

    SciTech Connect

    Freedman, B.; Pryde, E.H.; Mounts, T.L.

    1984-10-01

    Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of 60 degrees C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters was essentially complete in 1 hr. At moderate temperatures (32 degrees C), vegetable oils were 99% transesterified in ca. 4 hr with an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils. 30 references.

  13. Batch Production of Trimetylolpropane Ester from Palm Oil as Lubricant Base Stock

    NASA Astrophysics Data System (ADS)

    Zubaidah Sulaiman, Siti; Luqman Chuah, A.; Fakhru`L-Razi, A.

    A batch process for the ransesterification of Palm Oil Methyl Ester (POME) with trimethylolpropane (TMP) to TMP ester was investigated in a mini pilot reactor. The process was equipped with a high vacuum pump. The experimental studies explored effects of vacuum pressure, temperature, molar ratio, catalyst amount and agitator speed on the overall conversion. Five liters of TMP esters containing 83 to 87 w/w % triesterss (TE) were successfully synthesized after 2 h of reaction time Application of vacuum pump enhanced conversion of TE (w/w %) for the process. High catalyst amount resulted in higher conversion of TE (w/w %) but increased in solid content of the product. This has reduced the product yield due to inefficient separation by gravity settling.

  14. Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide Oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodornus J. (Inventor); Weiser, Erik S. (Inventor); SaintClair, Terry L. (Inventor)

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  15. Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodorous J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  16. The CGC enantiomer separation of 2-arylcarboxylic acid esters by using β-cyclodextrin derivatives as chiral stationary phases.

    PubMed

    Shi, Xueyan; Liu, Feipeng; Mao, Jianyou

    2016-03-17

    Chiral 2-arylcarboxylic acid esters are important intermediates in preparation of enantioenriched 2-arylpropionic acids type Non-steroidal anti-inflammatory drugs (NSAIDs). Enantiomer separation of 2-arylcarboxylic acid esters is crucial for evaluation of the asymmetric synthesis efficiency and the enantiomer excess of chiral 2-arylcarboxylic acid derivatives. The capillary gas chromatography (CGC) enantiomer separation of 17 pairs of 2-arylcarboxylic acid esters enantiomers was conducted by using seven different β-cyclodextrin derivatives (CDs) as chiral stationary phases. It was found that for the 7 pairs of 2-phenylpropionates enantiomers, CDs with both alkyl and acyl substituents especially 2,6-di-O-pentyl-3-O-butyryl-β-cyclodextrin exhibited better enantiomer separation abilities than the other CDs examined. For the 7 pairs of 2-(4-substituted phenyl)propionates enantiomers, 2,3,6-tri-O-methyl-β-cyclodextrin possessed better enantiomer separation abilities than the other CDs. Among the 3 pairs of 2-phenylbutyrates enantiomers examined, only methyl 2-phenylbutyrate enantiomers could be separated by three CDs among the 7 CDs tested, while enantiomers of ethyl 2-phenylbutyrate and isopropyl 2-phenylbutyrate couldn't be separated by any of the 7 CDs tested. Besides the structures of CDs, the structures of 2-arylcarboxylic acid esters including different ester moieties, substituents of phenyl, and different carboxylic acids moieties in 2-arylcarboxylic acid esters also affected the enantiomer separation results greatly. The CGC enantiomer separation results of 2-arylcarboxylic acid esters on different CDs are useful for solving the enantiomer separation problem of 2-arylcarboxylic acid esters. PMID:26920785

  17. Umpolung Reactions of α-Imino Esters: Useful Methods for the Preparation of α-Amino Acid Frameworks.

    PubMed

    Mizota, Isao; Shimizu, Makoto

    2016-04-01

    This paper summarizes our recent efforts toward the development of tandem reactions utilizing umpolung reactions of α-imino esters. A highly diastereoselective tandem N-alkylation-Mannich reaction of α-imino esters was developed. A tandem N-alkylation-addition reaction of α-imino esters derived from ethyl glyoxylate with various aldehydes proceeded to give 1,2-amino alcohols. The same reaction also proceeded efficiently using a novel flow system comprising two connected microreactors. Novel syntheses of α-quaternary alkynyl amino esters and allenoates were developed through the use of umpolung N-addition to β,γ-alkynyl α-imino esters, followed by regioselective acylation. In addition, a highly regioselective tandem N-alkylation-vinylogous aldol reaction of β,γ-alkenyl α-imino esters was discovered. N-Alkylation of α-iminophosphonates followed by a Horner-Wadsworth-Emmons reaction with aldehydes occurred to afford enamines, which can be used in a four-component coupling reaction with methyl vinyl ketone. α-N-Acyloxyimino esters served as highly efficient substrates for the N,N,C-trialkylation reaction to introduce various nucleophiles at the imino nitrogen and carbon atoms. PMID:26833635

  18. The Benzyl Ester Group of Amino Acid Monomers Enhances Substrate Affinity and Broadens the Substrate Specificity of the Enzyme Catalyst in Chemoenzymatic Copolymerization.

    PubMed

    Ageitos, Jose Manuel; Yazawa, Kenjiro; Tateishi, Ayaka; Tsuchiya, Kousuke; Numata, Keiji

    2016-01-11

    The chemoenzymatic polymerization of amino acid monomers by proteases involves a two-step reaction: the formation of a covalent acyl-intermediate complex between the protease and the carboxyl ester group of the monomer and the subsequent deacylation of the complex by aminolysis to form a peptide bond. Although the initiation with the ester group of the monomer is an important step, the influence of the ester group on the polymerization has not been studied in detail. Herein, we studied the effect of the ester groups (methyl, ethyl, benzyl, and tert-butyl esters) of alanine and glycine on the synthesis of peptides using papain as the catalyst. Alanine and glycine were selected as monomers because of their substantially different affinities toward papain. The efficiency of the polymerization of alanine and glycine benzyl esters was much greater than that of the other esters. The benzyl ester group therefore allowed papain to equally polymerize alanine and glycine, even though the affinity of alanine toward papain is substantially higher. The characterization of the copolymers of alanine and glycine in terms of the secondary structure and thermal properties revealed that the thermal stability of the peptides depends on the amino acid composition and resultant secondary structure. The current results indicate that the nature of the ester group drastically affects the polymerization efficiency and broadens the substrate specificity of the protease. PMID:26620763

  19. Tropane ethyl esters in illicit cocaine: isolation, detection, and determination of new manufacturing by-products from the clandestine purification of crude cocaine base with ethanol.

    PubMed

    Casale, John F; Boudreau, Danielle K; Jones, Laura M

    2008-05-01

    Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology. Seven ethyl ester homologues were formed in illicit cocaine from the transesterification of known tropane methyl esters or possibly ethyl esterification of their respective tropane C-2 carboxylic acids in the presence of ethanol. Exhibits containing these compounds were subjected to gas chromatographic-mass spectrometric analyses to determine their identity and were subsequently synthesized to verify their structures. Quantitative determinations were obtained from ion-pair chromatography isolation followed by gas chromatography with flame ionization detection. Specifically, hexanoylecgonine ethyl ester, cocaethylene, cis-cinnamoylecgonine ethyl ester, trans-cinnamoylecgonine ethyl ester, 3',4',5'-trimethoxybenzoylecgonine ethyl ester, cis-3',4',5'-trimethoxycinnamoylecgonine ethyl ester, and trans-3',4',5'-trimethoxycinnamoylecgonine ethyl ester were detected and characterized. When present, these compounds were detected at levels ranging from 8.6 x 10(-4) to 9.3 x 10(-1)% relative to cocaine. PMID:18471211

  20. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...