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Sample records for adipate ester contents

  1. Analysis of Adipate Ester Contents in PVC Plastics

    Berg, Rolf W.

    2006-01-01

    Plasticizers are needed in flexible PVC (PolyVinylChloride) products. There is serious concern that commonly used phthalate esters may harm life reproduction systems. To avoid the problems, instead adipate di-esters (AEs) of C8 to C10 alcohols are used as higher prized alternatives; e.g. di-2...

  2. ANALYSIS OF ADIPATE ESTER CONTENTS IN POLY(VINYL CHLORIDE) PLASTICS

    Berg, Rolf W.; Otero, Amalia Dopazo

    2006-01-01

    Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser can be used to determine the content of plasticizers in commercial flexible poly vinyl chloride (PVC) products. Our previous study [T. Nørbygaard, R.W. Berg, Analysis of phthalate ester content in PVC plastics by means of FT-...

  3. Poly(lactic acid/thermoplastic starch sheets: effect of adipate esters on the morphological, mechanical and barrier properties

    Marianne Ayumi Shirai

    2016-02-01

    Full Text Available Abstract Blends of poly(lactic acid (PLA and thermoplastic starch (TPS plasticized with adipate esters (diisodecyl adipate and diethyl adipate having different molecular weight were used to produce sheets. The calendering-extrusion process at a pilot scale was used, and the mechanical, barrier, and morphological characterization of the obtained materials were performed. The increase in the TPS content affected the mechanical properties of the sheets by increasing the elongation and decreasing the rigidity. TPS conferred a more hydrophilic character to the sheets, as observed from the water vapor permeability results. The sheets plasticized with diisodecyl adipate (DIA, having a higher molecular weight, had better mechanical and barrier properties than diethyl adipate (DEA plasticized sheets, indicating that DIA was more effective as plasticizer. Micrographs obtained by confocal laser microscopy and scanning electron microscopy showed different morphologies when different proportions of PLA and TPS were used (dispersed or co-continuous structures, which were strongly associated with the mechanical and barrier properties.

  4. Poly(glycerol adipate)-fatty acid esters as versatile nanocarriers

    Weiss, Verena M; Naolou, Toufik; Hause, Gerd;

    2012-01-01

    Poly(glycerol adipate) (PGA) is a biodegradable polymer with promising features for nanoparticulate drug carrier systems. By acylation of PGA with fatty acids, composite systems with amphiphilic properties can be obtained. Variation of the fatty acid (laurate, stearate and behenate) and their sub...... nanoparticles. With their diverse particle shapes and internal structures as well as their different thermal behavior, aggregate states and polarities, the systems offer promising possibilities as delivery systems for lipophilic, amphiphilic and water soluble drugs....

  5. Analysis of Polyadipate Ester Content in PVC Plastics by Means of FT-Raman Spectroscopy

    Berg, Rolf W.

    2006-01-01

    Plasticizers are needed in flexible PVC (PolyVinylChloride) products. There is serious concern that commonly used phthalate esters may harm life reproduction systems. To avoid the problems, instead adipate di-esters (AEs) of C8 to C10 alcohols are used as higher prized alternatives; e.g. di-2...

  6. Electrospun Scaffolds from Low Molecular Weight Poly(ester amides Based on Glycolic Acid, Adipic Acid and Odd or Even Diamines

    Sara Keiko Murase

    2015-05-01

    Full Text Available Electrospinning of regular poly(ester amides (PEAs constituted by glycolic acid, adipic acid and diamines with five and six carbon atoms has been carried out. Selected PEAs were constituted by natural origin products and could be easily prepared by a polycondensation method that avoids tedious protection and deprotection steps usually required for obtaining polymers with a regular sequence. Nevertheless, the synthesis had some limitations that mainly concerned the final low/moderate molecular weight that could be attained. Therefore, it was considered interesting to evaluate if electrospun scaffolds could still be prepared taking also advantage of the capability of PEAs to establish intermolecular hydrogen bonds. Results indicated that the crucial factor was the control of polymer concentration in the electrospun solution, being necessary that this concentration was higher than 40% (w/v. The PEA with the lowest molecular weight (Mw close to 8000 g/mol was the most appropriate to obtain electrospun samples with a circular cross-section since higher molecular sized polymers show solvent retention problems derived from the high viscosity of the electrospun solution that rendered ribbon-like morphologies after the impact of fibers into the collector. The studied PEAs were semicrystalline and biodegradable, as demonstrated by calorimetric and degradation studies. Furthermore, the new scaffolds were able to encapsulate drugs with anti-inflammatory and bacteriostatic activities like ketoprofen. The corresponding release and bactericide activity was evaluated in different media and against different bacteria. Finally, biocompatibility was demonstrated using both fibroblast and epithelial cell lines.

  7. NF EN 14103. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the ester and methylic ester content of linoleic acid; NF EN 14103. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en ester et en ester methylique de l'acide linolenique

    NONE

    2003-07-01

    This European standard aims at determining the ester and methylic ester content of fatty acids methylic esters (FAME) used as pure bio-fuels or as constituent of a heating or diesel fuel. This method allows also to determine the methylic ester content of linoleic acid. It allows to verify that the ester content of FAMEs is greater than 90% (m/m) and that the linoleic acid content is comprised between 1% (m/m) and 15% (m/m). The method is applicable to FAMEs with methylic ester contents comprised between C14 and C24. (J.S.)

  8. Comparison of hepatic peroxisome proliferative effect and its implication for hepatocarcinogenicity of phthalate esters, di(2-ethylhexyl) phthalate, and di(2-ethylhexyl) adipate with a hypolipidemic drug.

    Reddy, J K; Reddy, M K; Usman, M. I.; Lalwani, N D; M.S. Rao

    1986-01-01

    Peroxisome proliferation is inducible in hepatocytes of rodent and nonrodent species by structurally dissimilar hypolipidemic drugs and certain phthalate ester plasticizers. The induction of peroxisome proliferation appears to be a tissue specific response limited largely to the hepatocyte. Peroxisome proliferation is associated with increases in the activity of the H2O2-generating peroxisomal fatty acid beta-oxidation system and in the amount of peroxisome proliferation-associated 80,000 MW ...

  9. Influence of low contents of superhydrophilic MWCNT on the properties and cell viability of electrospun poly (butylene adipate-co-terephthalate) fibers.

    Rodrigues, Bruno V M; Silva, Aline S; Melo, Gabriela F S; Vasconscellos, Luana M R; Marciano, Fernanda R; Lobo, Anderson O

    2016-02-01

    The use of poly (butylene adipate-co-terephthalate) (PBAT) in tissue engineering, more specifically in bone regeneration, has been underexplored to date due to its poor mechanical resistance. In order to overcome this drawback, this investigation presents an approach into the preparation of electrospun nanocomposite fibers from PBAT and low contents of superhydrophilic multi-walled carbon nanotubes (sMWCNT) (0.1-0.5wt.%) as reinforcing agent. We employed a wide range of characterization techniques to evaluate the properties of the resulting electrospun nanocomposites, including Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM), tensile tests, contact angle measurements (CA) and biological assays. FE-SEM micrographs showed that while the addition of sMWCNT increased the presence of beads on the electrospun fibers' surfaces, the increase of the neat charge density due to their presence reduced the fibers' average diameter. The tensile test results pointed that sMWCNT acted as reinforcement in the PBAT electrospun matrix, enhancing its tensile strength (from 1.3 to 3.6MPa with addition of 0.5wt.% of sMWCNT) and leading to stiffer materials (lower elongation at break). An evaluation using MG63 cells revealed cell attachment into the biomaterials and that all samples were viable for biomedical applications, once no cytotoxic effect was observed. MG-63 cells osteogenic differentiation, measured by ALP activity, showed that mineralized nodules formation was increased in PBAT/0.5%CNTs when compared to control group (cells). This investigation demonstrated a feasible novel approach for producing electrospun nanocomposites from PBAT and sMWCNT with enhanced mechanical properties and adequate cell viability levels, which allows for a wide range of biomedical applications for these materials. PMID:26652433

  10. Analysis of phthalate ester content in poly(vinyl chloride) plastics by means of Fourier transform Raman spectroscopy

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    Fourier transform (FT) Raman spectroscopy is applied to a range of phthalate ester plasticizers in pure form as well as in poly(vinyl chloride) (PVC) samples. It is found that phthalate esters as a group can be identified by a set of six characteristic Raman bands. FT-Raman spectra of 22 phthalat...... esters are given. It is demonstrated that the presence of phthalate esters in PVC products is readily detectable by FT-Raman spectroscopy. By use of proper ref. samples quant. detn. of the phthalate ester content becomes possible as well....

  11. The effect of frying on glycidyl esters content in palm oil.

    Aniołowska, Magda; Kita, Agnieszka

    2016-07-15

    The changes in palm oil, as affected by frying temperature, and content of the glycidyl esters (GEs) were studied. Potato chips were fried intermittently in palm oil, which was heated for 8 h daily over five consecutive days. Frying was conducted at three frying temperatures: 150, 165 and 180 °C. Thermo-oxidative alterations of the oil were measured by acid and anisidine values, changes in fatty acid composition, total polar components, polar fraction composition and colour components formation. Content of GE was measured by liquid chromatography-mass spectrometry. Results showed that amount of products of hydrolysis, oxidation and polymerization (excluding decrease of degree of unsaturation) increased significantly as a function of frying temperature and time. Between GEs of fatty acids the most abundant were esters of palmitic and oleic acids. With increasing temperature and frying time, the content of GE decreased. The extent of GE decrease was correlated with degree of oil degradation. PMID:26948594

  12. RENEWABLE ENERGY CONTENT OF FATTY ACID METHYL ESTERS (FAME AND GLYCEROL

    Giuseppe Toscano

    2009-12-01

    Full Text Available Fatty acid methyl esters (FAME and glycerol produced by transesterification reaction contain atoms that in the reagents belong to methanol and, therefore, are not renewable. A method to evaluate the content of the renewable and non-renewable energetic fraction, released during their combustion, was 52 Fig. 2 - Correlation between EFNR and NCM of FAME. Fig. 3 - Correlation between NCM and NS. Fig. 4 - Correlations between EFNR and NS. 07_Toscano(541_47 26-01-2010 9:35 Pagina 52 developed using a thermochemical criteria, based on bond dissociation energies and the knowledge of the molecular structure of the reagents and the products. Results show that the fraction of non-renewable energy in the most diffused FAME is lower than 1% depending on the lengths of the carbonaceous methyl esters. Meanwhile, the energetic supply for the GL of this fraction is about 1.6%. The data reported in this document can be used to develop a criteria that corrects the fiscal mechanism aspects of some renewable energy products.

  13. High biobased content epoxy-anhydride thermosets from epoxidized sucrose esters of Fatty acids.

    Pan, Xiao; Sengupta, Partha; Webster, Dean C

    2011-06-13

    Novel highly functional biobased epoxy compounds, epoxidized sucrose esters of fatty acids (ESEFAs), were cross-linked with a liquid cycloaliphatic anhydride to prepare polyester thermosets. The degree of cure or conversion was studied using differential scanning calorimetry (DSC), and the sol content of the thermosets was determined using solvent extraction. The mechanical properties were studied using tensile testing to determine Young's modulus, tensile stress, and elongation at break. Dynamic mechanical analysis (DMA) was used to determine glass-transition temperature, storage modulus, and cross-link density. The nanomechanical properties of the surfaces were studied using nanoindentation to determine reduced modulus and indentation hardness. The properties of coatings on steel substrates were studied to determine coating hardness, adhesion, solvent resistance, and mechanical durability. Compared with the control, epoxidized soybean oil, the anhydride-cured ESEFAs have high modulus and are hard and ductile, high-performance thermoset materials while maintaining a high biobased content (71-77% in theory). The exceptional performance of the ESEFAs is attributed to the unique structure of these macromolecules: well-defined compact structures with high epoxide functionality. These biobased thermosets have potential uses in applications such as composites, adhesives, and coatings. PMID:21561167

  14. Analysis of Phthalate Ester Content in PVC Plastics by means of FT-Raman Spectroscopy

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    -phenyl group, and as the relative intensities of the six bands vary only slightly from one phthalate ester to the next one we have obtained an identifiable, characteristic fingerprint of the phthalate ester group as a whole. By use of the set of six bands, which are common to all the measured Raman spectra, we...

  15. Kapok oil methyl esters

    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 specifications in biodiesel standards and some prior results. The kinematic viscosity of kapok oil methyl esters was greater than expected, an observation traced to the elevated amounts of methyl esters with cyclic moieties. Overall, kapok oil is a potential biodiesel feedstock. The 1H and 13C NMR spectra of kapok methyl esters are reported. - Highlights: • Methyl esters of kapok oil generally acceptable as a biodiesel fuel. • Kapok oil methyl esters a fuel with elevated content of fatty acid methyl esters containing cyclic moieties. • Kinematic viscosity of kapok oil methyl esters elevated likely due to fatty ester methyl esters with cyclic moieties. • Discusses and compares present results with prior literature

  16. Influence of adipic acid on tensile and morphology properties of linear low density polyethylene/rambutan peels flour blends

    Nadhirah, A. A.; Sam, S. T.; Noriman, N. Z.; Ragunathan, S.; Ismail, H.

    2015-07-01

    This study investigate about the tensile and morphological properties of degradable polymer produced from linear low density polyethylene/rambutan peel flour (LLDPE/RPF) blends and adipic acid (AA) was used as a compatibilizer by varying the rambutan peel flour (RPF) amount from 0-25wt%. The samples were subjected to tensile and morphological tests. AA compatibilized showed higher strength compared to uncompatibilized blends. The Young's modulus for LLDPE/RPF blends increased with increasing flour content. However, the addition of adipic acid had reduced the Young's Modulus.

  17. Toward biotechnological production of adipic acid and precursors from biorenewables.

    Polen, Tino; Spelberg, Markus; Bott, Michael

    2013-08-20

    Adipic acid is the most important commercial aliphatic dicarboxylic acid in the chemical industry and is primarily used for the production of nylon-6,6 polyamide. The current adipic acid market volume is about 2.6 million tons/y and the average annual demand growth rate forecast to stay at 3-3.5% worldwide. Hitherto, the industrial production of adipic acid is carried out by petroleum-based chemo-catalytic processes from non-renewable fossil fuels. However, in the past years, efforts were made to find alternative routes for adipic acid production from renewable carbon sources by biotechnological processes. Here we review the approaches and the progress made toward bio-based production of adipic acid. PMID:22824738

  18. CCN activation experiments with adipic acid: effect of particle phase and adipic acid coatings on soluble and insoluble particles

    S. S. Hings

    2008-07-01

    Full Text Available Slightly soluble atmospherically relevant organic compounds may influence particle CCN activity and therefore cloud formation. Adipic acid is a frequently employed surrogate for such slightly soluble organic materials. The 11 published experimental studies on the CCN activity of adipic acid particles are not consistent with each other nor do they, in most cases, agree with the Köhler theory. The CCN activity of adipic acid aerosol particles was studied over a significantly wider range of conditions than in any previous single study. The work spans the conditions of the previous studies and also provides alternate methods for producing "wet" (deliquesced solution droplets and dry adipic acid particles without the need to produce them by atomization of aqueous solutions. The experiments suggest that the scatter in the previously published CCN measurements is most likely due to the difficulty of producing uncontaminated adipic acid particles by atomization of solutions and possibly also due to uncertainties in the calibration of the instruments. The CCN activation of the small (dm<150 nm initially dry particles is subject to a deliquescence barrier, while for the larger particles the activation follows the Köhler curve. Wet adipic acid particles follow the Köhler curve over the full range of particle diameters studied. In addition, the effect of adipic acid coatings on the CCN activity of both soluble and insoluble particles has also been studied. When a water-soluble core is coated by adipic acid, the CCN-hindering effect of particle phase is eliminated. An adipic acid coating on hydrophobic soot yields a CCN active particle. If the soot particle is relatively small (dcore≤102 nm, the CCN activity of the coated particles approaches the deliquescence line of adipic acid, suggesting that the total size of the particle determines CCN activation and the soot core acts as a scaffold.

  19. Biodegradable Poly(ester urethane)urea Elastomers with Variable Amino Content for Subsequent Functionalization with Phosphorylcholine

    Fang, Jun; Ye, Sang-Ho; Shankarraman, Venkat; Huang, Yixian; Mo, Xiumei; Wagner, William R.

    2015-01-01

    While surface modification is well suited for imparting biomaterials with specific functionality for favorable cell interactions, the modification of degradable polymers would be expected to provide only temporary benefit. Bulk modification by incorporating pendant reactive groups for subsequent functionalization of biodegradable polymers would provide a more enduring approach. Towards this end, a series of biodegradable poly(ester urethane)urea elastomers with variable amino content (PEUU-NH2 polymers) were developed. Carboxylated phosphorycholine was synthesized and conjugated to the PEUU-NH2 polymers for subsequent bulk functionalization to generate PEUU-PC polymers. Synthesis was verified by 1H NMR, X-ray photoelectron spectroscopy and ATR-FTIR. The impact of amine incorporation and phosphorylcholine conjugation was shown on mechanical, thermal and degradation properties. Water absorption increased with increasing amine content, and further with PC conjugation. In wet conditions, tensile strength and initial modulus generally decreased with increasing hydrophilicity, but remained in the range of 5–30 MPa and 10–20 MPa respectively. PC conjugation was associated with significantly reduced platelet adhesion in blood contact testing and the inhibition of rat vascular smooth muscle cell proliferation. These biodegradable PEUU-PC elastomers offer attractive properties for applications as non-thrombogenic, biodegradable coatings and for blood-contacting scaffold applications. Further, the PEUU-NH2 base polymers offer the potential to have multiple types of biofunctional groups conjugated onto the backbone to address a variety of design objectives. PMID:25132273

  20. [Effect of municipal sludge and chemical fertilizers on phthalic acid esters (PAEs) contents in Ipomoea aquatica grown on paddy soils].

    Cai, Quanying; Mo, Cehui; Zhu, Xizhen; Wu, Qitang; Wang, Boguang; Jiang, Chengai; Li, Haiqin

    2003-11-01

    GC/MS determinations on six phthalic acid esters (PAEs) in Ipomoea aquatic grown on potted paddy soil fertilized with municipal sludge and chemical fertilizers showed that the total contents of PAEs (sigma PAEs) in Ipomoea aquatic aboveground parts ranged from 2.129 mg.kg-1 to 7.111 mg.kg-1, decreasing in order of Guangzhou sludge + fertilizers (7.111 mg.kg-1) > Guangzhou sludge (4.767 mg.kg-1) > Foshan sludge (3.569 mg.kg-1) > Foshan sludge + fertilizers (3.305 mg.kg-1) > fertilizers (2.638 mg.kg-1) > control (2.129 mg.kg-1), indicating that compared with control, fertilization increased sigma PAEs in Ipomoea aquatica to a different extent. Only certain compounds of PAEs in different treatments of Ipomoea aquatica were dominant, e.g., butylbenzyl phthalate (BBP) in control, chemical fertilizers, Foshan sludge, and Guangzhou sludge accounted for 40% to 80% of sigma PAEs, di-n-butyl phthalate(DnBP) in foshan sludge + chemical fertilizers accounted for 56%, while di-n-octyl phthalate(DnOP), di(2-ethylhexyl)phthalate(DEHP) and BBP in Guangzhou sludge + chemical fertilizers accounted for approximately 30%. sigma PAEs and the contents of its most compounds were higher in the plants of Ipomoea aquatica than in its roots to a different extent. PMID:14997666

  1. Polymerization of Pyrrole and Thiophene on Polyethylene Adipate Electrodes

    ERTURAN, Seyfettin; TORAMAN, Burcu YALVAÇ and Sena

    1998-01-01

    Polymerizations of pyrrole and thiophene on a platinum foil coated by polyethylene adipate (PEA) were carried out in acetonitrile by electrochemical methods. Different compositions of semi-conducting composite films of PEA/Polypyrrole(PPy), PEA/Polythiophene(PT) were prepared by the electrochemical polymerization of pyrrole and thiophene on PEA electrode. The polymerization was possible only for a certain thickness of the polyethylene adipate(PEA) on the platinum. Conductivities of PEA/PPy, P...

  2. Emerging catalytic processes for the production of adipic acid

    Van de Vyver, Stijn; Roman, Yuriy

    2012-01-01

    Research efforts to find more sustainable pathways for the synthesis of adipic acid have led to the introduction of new catalytic processes for producing this commodity chemical from alternative resources. With a focus on the performance of oxygen and hydrogen peroxide as preferred oxidants, this minireview summarizes recent advances made in the selective oxidation of cyclohexene, cyclohexane, cyclohexanone and n-hexane to adipic acid. Special attention is paid to the exploration of catalytic...

  3. Analysis of phthalate ester content in poly(vinyl chloride) plastics by means of Fourier transform Raman spectroscopy

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    Fourier transform (FT) Raman spectroscopy is applied to a range of phthalate ester plasticizers in pure form as well as in poly(vinyl chloride) (PVC) samples. It is found that phthalate esters as a group can be identified by a set of six characteristic Raman bands. FT-Raman spectra of 22 phthalate...

  4. 21 CFR 184.1009 - Adipic acid.

    2010-04-01

    ... also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid oxidation... ethanol. The melting range of the ester is 153° to 154 °C. (c) The ingredient is used as a flavoring agent as defined in § 170.3(o)(12) of this chapter; leavening agent as defined in § 170.3(o)(17) of...

  5. Aufwachverhalten von adipösen Patienten nach Narkosen mit Desfluran oder Isofluran

    Salz, Svenja

    2003-01-01

    Aufgrund der physikochemischen Eigenschaften (niedriger Fett- und Blutlöslichkeitskoeffizient) von Desfluran kann man bei adipösen Patienten eine kürzere postoperative Erholungsphase erwarten. Die vorliegende Studie untersuchte, ob adipöse Patienten nach einer Desflurannarkose schneller aus dem Aufwachraum (AWR) zu verlegen sind als Patienten, die mit Isofluran narkotisiert wurden. 40 adipöse Patienten erhielten eine mindestens 2-stündige standardisierte Narkose mit Desfluran bzw....

  6. Avocado and olive oil methyl esters

    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, including commodity oils, however, the methyl esters of avocado and olive oil would likely be suitable as biodiesel fuel. In order to expand the database and comprehensive evaluation of the properties of vegetable oil esters, in this work the fuel-related properties of avocado and olive oil methyl esters, which exhibit similar fatty acid profiles including high oleic acid content, are determined. The cetane numbers of avocado oil methyl esters and olive oil methyl esters are relatively high, determined as 59.2 and 62.5, respectively, due to their elevated content of methyl oleate. Other properties are well within the ranges specified in biodiesel standards. The cloud points of both esters are slightly above 0 °C due to their content of saturated esters, especially methyl palmitate. Overall, avocado and olive oil yield methyl esters with fuel properties comparable to methyl esters from other commodity vegetable oils. The 1H and 13C NMR spectra of avocado and olive oil methyl esters are reported. -- Highlights: • Methyl esters of avocado and olive oil meet biodiesel fuel standards. • Provides comparison for methyl esters of other vegetable oils with high oleic content. • Discusses and compares present results with prior literature

  7. Tunneling recombination luminescence of glassy polyethylene adipate γ-irradiated at low temperature and effect of electron scavengers

    The isothermal luminescence (ITL) from glassy polyethylene adipate (PEA) γ-irradiated at 77 K was observed over a long period of time, together with effect of the electron scavengers on it. The decay behavior of ITL is similar to that of polyethylene terephthalate or polycrystalline PEA obtained previously, so that the decay obeys the decay function I(t) = I0/(1 + αt)sup(m). The detailed discussion on the parameters included in the decay function is given. Differences in the parameters between different materials or different physical states are found not to be very large, except the parameter I0. Addition of biphenyl into PEA enhances considerably the intensity of ITL and causes the luminescence center to exchange from the ester cation into the biphenyl cation. In the biphenyl doped PEA, the possibility of the triplet-triplet energy transfer from the excited ester group to the biphenyl and the positive charge transfer from the ester cation to the biphenyl are shown. (author)

  8. 隔夜皂化法测定白酒中总酯含量%Determination of Total Ester Content in Liquor by Overnight Saponification

    李华萍; 李春江; 李燕

    2015-01-01

    对隔夜皂化法检验白酒总酯含量进行了实验研究,结果表明,在20℃下,静置16 h,得到的实验结果与回流皂化法测得的结果有很好的一致性,相对标准偏差为1.5%~2.1%,加标回收率为98.4~102.9%。%The total ester content in liquor with overnight saponification was experimentally studied, the results showed that at 20 ℃,standing 16h,the experimental results obtained with the results of reflux saponification are in good agreement with the relative standard deviation 1.5% to 2.1% and the recovery rate was 98.4 ~102.9%.

  9. Effects of pH and citric acid contents on characteristics of ester-derived BaFe12O19 powder

    The single domain size of BaFe12O19 powder with crystallite sizes less than 200 nm was produced using a citric acid precursor method. Fe3+ and Ba2+, in a molar ratio of 12, were chelated by COOH- in an aqueous solution. After ethylene glycol additions, esterification, dehydration, and calcination led to the formation of ester-derived BaFe12O19 powder. High pH and/or high citric acid contents in the starting solution are required to complete chelate metallic ions in the solution and to form pure barium ferrite powder at 1073 K. Pure single magnetic domain BaFe12O19 particles of M(30 kOe)∼54 emu/g, Mr∼28 emu/g, and Hc∼3.7 kOe were produced using [citric acid]/[metallic ions]=1.5 and pH≥7

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

    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. NF EN 14109. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the potassium content by atomic absorption spectroscopy; NF EN 14109. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en potassium par spectrometrie d'absorption atomique

    NONE

    2003-07-01

    This European standard specifies a method of determination of sodium contents for concentrations equal or greater than 0.5 mg/kg. This method is applicable to fatty acids methylic esters (FAME) intended to be incorporated to mineral oils. This method involves dangerous compounds, operations and equipments which are not considered in the text of the standard. (J.S.)

  12. NF EN 14108. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the sodium content by atomic absorption spectroscopy; NF EN 14108. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en sodium par spectrometrie d'obsorption atomique

    NONE

    2003-07-01

    This European standard specifies a method of determination of sodium contents for concentrations equal or greater than 1 mg/kg. This method is applicable to fatty acids methylic esters (FAME) intended to be incorporated to mineral oils. This method involves dangerous compounds, operations and equipments which are not considered in the text of the standard. (J.S.)

  13. Synthesis and NMR characterization of aliphatic-aromatic copolyesters by reaction of poly(ethylene terephthalate post-consumer and poly(ethylene adipate

    Alessandra F. Baldissera

    2005-03-01

    Full Text Available An aliphatic-aromatic copolyester of poly(ethylene terephthalate, PET, and poly(ethylene adipate, PEA, PET-co-PEA, was synthesized by the high temperature melt reaction of post-consumer PET and PEA. As observed by NMR spectroscopy, the reaction yielded random copolyesters in a few minutes through ester-interchange reactions, even without added catalyst. The copolyesters obtained in the presence of a catalyst presented higher intrinsic viscosity than that obtained without the addition of catalyst, due to simultaneous polycondensation and ester-interchange reactions. The structure of the aliphatic-aromatic copolyesters obtained in different PET/PEA ratio is random as observed by NMR analysis.

  14. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    2010-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  15. Die respiratorische Katastrophe des adipösen Patienten

    Staudinger T

    2012-01-01

    Full Text Available Beim morbid adipösen Patienten besteht neben der Neigung zu Atelektasen einerseits eine restriktive Lungenerkrankung mit herabgesetzten Lungenvolumina und damit einer deutlich reduzierten Reservekapazität, andererseits das Bild einer chronischen Obstruktion. Der Sauerstoffpartialdruck ist erniedrigt und es liegt häufig eine chronische Hyperkapnie vor. Diese Veränderungen bewirken eine Atmung unter submaximaler Heranziehung kompensatorischer Mechanismen, sodass ein zusätzlicher Trigger, wie z. B. eine Infektion, Bettlägerigkeit oder ein anderer akut krankhafter Prozess, rasch zu einer völligen und lebensbedrohlichen Dekompensation des respiratorischen Systems führen kann. Obwohl adipöse Patienten bei kritischer Erkrankung eine bessere Prognose als Normal- und Untergewichtige haben (so genanntes „Obesity Paradoxon“, leiden morbid Adipöse (BMI 40 an zahlreichen Komorbiditäten, die diesen Effekt wieder zunichtemachen. Spezielle therapeutische Maßnahmen bei respiratorischen Krisen sind eine adäquate Lagerung (Vermeidung von Flachund Kopftieflage, durchgehende Oberkörperhochlagerung bei beatmungspflichtigem Lungenversagen Bauchlagerung, die Verwendung von auf das erhöhte Körpergewicht abgestimmten Materialien wie Spezialbetten, Stühlen und Instrumenten, sowie eine Beatmungstherapie mit adäquat hohem „Positive End-Expiratory Pressure“ (PEEP nach entsprechend gut vorbereiteter endotrachealer Intubation (Aspirationsprophylaxe, Positionierung unter Einbeziehung von Spontanatmungsanteilen und unter Berücksichtigung des idealen (nicht absoluten! Körpergewichts für die Berechnung der Atemzugsvolumina. Dem Wissen um pathophysiologische Veränderungen und spezifische Therapiemaßnahmen bei respiratorischer Insuffizienz kommt im Rahmen des Managements eines Patienten mit Adipositas permagna eine entscheidende Rolle zu und es trägt mit Sicherheit dazu bei, das akute Problem erfolgreich und komplikationsarm zu beherrschen.

  16. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate) Biocomposites

    Mohamad Zaki AB Rahman; Wan Md Zin Wan Yunus; Nor Azowa Ibrahim; Sanaz Abdolmohammadi; Samira Siyamak

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fib...

  17. Contents

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  18. Structure-property relationship of aliphatic segmented poly(ester amide)s

    Garg, Priya

    2010-01-01

    This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characteri...

  19. Determination of the antioxidant activity based on the content changes in fatty acid methyl esters in vegetable oils

    Housam Haj Hamdo; Zaid Al-Assaf; Warid Khayata

    2014-01-01

    Free radicals,which are generated in several biochemical reactions in the body,have been implicated as mediators of many diseases,including cancer,atherosclerosis and heart diseases.Although the endogenous antioxidants can scavenge these free radicals,they are often insufficient to maintain the in vivo redox balance.The antioxidant activity (AOA) was examined by addition of each tested antioxidants [alpha-tocopherol (a-T),beta-tocopherol (β-T),gamma-tocopherol (γ-T),delta-tocopherol (δ-T),butylated hydroxyanisole (BHA),2,6-di-tert-butyl-4-methylphenol (BHT),and ascorbyle palmitate (AP)] to four types of different vegetable oils (sunflower oil,soybean oil,corn oil and olive oil).Moreover,content changes in fatty acids were then investigated every 3 months during the storage period.The results showed that the AOA was different among the tested antioxidants.The AOA for BHA was the most for different types of oil compared with other antioxidants,whereas the δ-T possessed the lowest AOA.

  20. in situ ring-opening polymerization of hydroxyapatite/poly(ethylene adipate)--(ethylene terephthalate) biomimetic composites

    Punnama Siriphannon; Pathavuth Monvisade

    2013-02-01

    Hydroxyapatite/poly(ethylene adipate)--poly(ethylene terephthalate) biomaterials (HAp/PEA--PET) have been prepared by ring opening polymerization (ROP) of cyclic oligo(ethylene adipate)--oligo(ethylene terephthalate) (C-OEA--C-OET) in the porous hydroxyapatite (HAp) scaffolds at 250 °C for 24 h under vacuum. The content of ROP-PEA--PET in the HAp/PEA--PET composite was about 20 wt% with the values of number average molecular weight ($\\bar{M}$n) and weight average molecular weight ($\\bar{M}$W) of 3380 and 7160 g/mol, respectively. Compressive strength and modulus of the HAp/PEA--PET composites were about 29 and 246 MPa, respectively. These mechanical properties were higher than those of the porous HAp templates and natural cancellous bone. In vitro bioactivity of the HAp/PEA--PET composites was studied by soaking in simulated body fluid (SBF) under the flowing system at the rate of 130 mL/day for 7, 14, 21 and 28 days. The formation of hydroxyapatite nanocrystals was observed on the composite surfaces through the consumption of calcium and phosphorus from the SBF solution, indicating the bioactivity of these HAp/PEA--PET composites. These results indicated the competency of HAp/PEA--PET composites for biomedical applications.

  1. 78 FR 33748 - Diisopropyl Adipate; Exemption From the Requirement of a Tolerance

    2013-06-05

    ... discussed in this unit. The acute oral toxicity of diisopropyl adipate in rodents, as expressed as an LD 50... adipate is about 6,600 mg/kg and in the rabbit, 5,000 mg/kg. In the dog, the acute oral LD 50 of... In the Federal Register of August 22, 2012 (77 FR 50661) (FRL-9358- 9), EPA issued a notice...

  2. NF EN 14106. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the free glycerol content; NF EN 14106. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en glycerol libre

    NONE

    2003-07-01

    This European standard specifies a gas chromatography method of determination of the free glycerol content of fatty acids methylic esters (FAME) for concentrations comprised between 0.005% and 0.070%. The objective of this method is to evaluate the quality of the FAMEs in terms of trans-esterification of their by-products content, such as glycerol, which can change the fuel combustion properties. This method involves dangerous compounds, operations and equipments which are not considered in the text of the standard. (J.S.)

  3. Relationship between adipic acid concentration and the core symptoms of autism spectrum disorders.

    Puig-Alcaraz, Carmen; Fuentes-Albero, Milagros; Cauli, Omar

    2016-08-30

    Dicarboxylic acids are an important source of information about metabolism and potential physiopathological alterations in children with autism spectrum disorders (ASDs). We measured the concentration between dicarboxylic adipic and suberic acids in children with an ASD and typically-developing (TD) children and analyzed any relationships between the severity of the core symptoms of ASDs and other clinical features (drugs, supplements, drugs, or diet). The core symptoms of autism were evaluated using the DSM-IV criteria, and adipic acid and suberic acid were measured in urine samples. Overall, no increase in the concentration of adipic acid in children with ASDs compared to TD children, however when considering vitamin B supplementation in ASD there were significantly increased level of urinary adipic acid in children with an ASD not taking vitamin B supplementation compared to supplemented children or to TD children. No significant difference were observed in suberic acid. Interestingly, the increase in adipic acid concentration was significantly and indirectly correlated with the severity of the deficit in socialization and communication skills in children with an ASD. Therefore, therapeutic treatments aimed at decreasing adipic acid concentration might not be beneficial for treating the core symptoms of ASDs. PMID:27259135

  4. Biodegradação de alcoóis, ftalatos e adipatos em um solo tropical contaminado Biodegradation of alcohol, phthalates and adipates in a tropical soil

    Ieda Domingues Ferreira

    2010-01-01

    Full Text Available The adipic and phthalic acid esters are plasticizers, have low water solubility, high partition octanol/water coefficients (Kow and accumulate in soil and sediments. These compounds are considered teratogenic, carcinogenic and endocrine disruptors chemicals. This study evaluated the bioremediation of tropical soil contaminated with plasticizers process wastes, in aerobic conditions, with and without introduction of acclimated bacteria. It was selected 200 kg of contaminated tropical soil for the biodegradation study. The plasticizers concentrations in soil ranged between 153 mgDOA/kg up to 15552 mgDIDP/kg and after 90 days of biodegradation, the lower removal efficiencies were 72% with a 1-2 log simultaneous bacterial growth.

  5. A study on reactive blending of (poly lactic acid) and poly (butylene succinate co adipate)

    Bureepukdee, C.; Suttiruengwong, S.; Seadan, M.

    2015-07-01

    This research aims to study the blending of Polylactic acid (PLA) and Polybutylene succinate co adipate (PBSA) in order to understand the role of peroxide in free radical reaction on the compatibilization between these two biodegradable polyesters. Various ratios of PLA/PBSA blends with and without reactive agents were prepared in the twin screw extruder. Two types of peroxides, Di (tert-butylperoxyisopropyl) benzene (DTBP) and 2, 5-Dimethyl-2, 5-(t-butylperoxy) hexane (DTBH), were used with various concentrations to compare. From the torques measurement, DTBP was more reactive with PLA and PBSA than DTBH. PLA and PBSA 80:20, 60:40, 50:50, 40:60, and 20:80% by weight were melt-blended in a twin screw extruder. The reactive polymer blends were also prepared for the same ratios of the blends with addition of 0.08 and 0.1 phr of DTBP. The mechanical, thermal, rheological, and morphological properties were investigated. The impact strengths of the non-reactive blend increased with the increasing in PBSA content. The optimal impact strength was obtained at 40%wt of PBSA with 0.1 phr of DTBP. Adding 0.08 and 0.1 phr of DTBP led to the co continuous phase morphology of PLA/PBSA blends. The per cent crystallinity of PLA increased when blended with PBSA. PBSA might induce the crystallization of PLA.

  6. Properties of alkali-solubilized collagen solution crosslinked by N-hydroxysuccinimide activated adipic acid

    Chen, Yihui; Zhang, Min; Liu, Wentao; Li, Guoying

    2011-03-01

    The effect of N-hydroxysuccinimide activated adipic acid (NHS-AA) on the properties of alkali-solubilized collagen solutions was examined. The residual amino group content in crosslinked collagen, determined by trinitrobenzensulfonic acid (TNBS) assay, was decreased with increasing NHS-AA concentration. The results from differential scanning calorimeter (DSC) indicated that the maximum denaturation temperature ( T d) of crosslinked collagen solution was about 4.2°C higher than that of un-crosslinked collagen solution (36.6°C). Moreover, the values of storage modulus ( G'), loss modulus ( G″) and complex viscosity ( η*), obtained by means of dynamic frequency sweeps, were increased as NHS-AA concentration added up to 1.5 mM, and then decreased slightly when further increased NHS-AA concentration. Besides, for collagen solution crosslinked with 1.5 mM NHS-AA, dynamic denaturation temperature ( T dd) was about 1.1°C lower than T d (40.8°C), and the Arrhenius-type time-temperature superposition (TTS) principle was applied to yield the activation energy to be 474.4 kJmol-1.

  7. NF EN 14105. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the free- and total-glycerol content and of the mono-, di-, and triglycerides content. Reference method; NF EN 14105. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en glycerols libre et total et en mono-, di- et triglycerides. Methode de reference

    NONE

    2003-07-01

    This European standard specifies a method of determination of the free glycerol and of the residual mono-, di-, and triglycerides content in fatty acids methylic esters (FAME) which will be incorporated in mineral oils. The total glycerol content is then determined from the obtained results. This method is adapted to colza, sunflower and soja oil FAMEs but not to copra or palm oil-based FAMEs because of the risk of peak superimposition. This method involves dangerous compounds, operations and equipments which are not considered in the text of the standard. (J.S.)

  8. One-pot room-temperature conversion of cyclohexane to adipic acid by ozone and UV light.

    Hwang, Kuo Chu; Sagadevan, Arunachalam

    2014-12-19

    Nitric acid oxidation of cyclohexane accounts for ~95% of the worldwide adipic acid production and is also responsible for ~5 to 8% of the annual worldwide anthropogenic emission of the ozone-depleting greenhouse gas nitrous oxide (N2O). Here we report a N2O-free process for adipic acid synthesis. Treatment of neat cyclohexane, cyclohexanol, or cyclohexanone with ozone at room temperature and 1 atmosphere of pressure affords adipic acid as a solid precipitate. Addition of acidic water or exposure to ultraviolet (UV) light irradiation (or a combination of both) dramatically enhances the oxidative conversion of cyclohexane to adipic acid. PMID:25525242

  9. Metabolic network analysis of an adipoyl-7-ADCA-producing strain of Penicillium chrysogenum: Elucidation of adipate degradation

    Thykær, Jette; Christensen, Bjarke; Nielsen, Jens

    2002-01-01

    An adipoyl-7-ADCA-producing, recombinant strain of Penicillium chrysogenum was characterized by metabolic network analysis, with special focus on the degradation of adipate and determination of the metabolic fluxes. Degradation of the side-chain precursor, adipate, causes an undesired consumption...

  10. Development of silver/titanium dioxide/chitosan adipate nanocomposite as an antibacterial coating for fruit storage

    A novel nanocomposite of silver/titanium dioxide/chitosan adipate (Ag/TiO2/CS) was developed through photochemical reduction using a chitosan adipate template. Chitosan served as a reducing agent for the metal ions, and anchored metal ions by forming Ag–N coordination bonds and electrostatic attract...

  11. 电位滴定法测定白酒总酯的不确定度分析%Evaluation of the Uncertainty in the Determination of Total Esters Content in Liquor by Automatic Potentiometric Titration

    刘妙芬; 邱佩丽; 丁怡; 黄秋婷; 彭程

    2012-01-01

    The uncertainty components in the determination of total esters content in liquor by potentiometric titration were analyzed and quantified according to the evaluation principles of uncertainty.The effects of measurement repeatability,sampling,preparation process of standard solution,burette and molar weight etc on the uncertainty were also investigated to establish the mathematical model of uncertainty.The combined standard measurement uncertainty of total ester content was calculated to be 0.00836 g / L and the expanded uncertainty was 0.0167g / L(k = 2).%根据测量不确定度的评定原理和方法,对电位滴定法测定白酒中总酯含量过程的不确定度分量进行分析和定量,分析了测量重复性、取样、标准滴定液的标定过程、滴定管和摩尔质量等因素对测量不确定度的影响,建立了不确定度的数学模型。计算得到总酯的合成标准不确定度为uc=0.00836 g/L,扩展不确定度为U=0.0167 g/L;k=2。

  12. PROCEEDINGS: EPA'S INDUSTRY BRIEFING ON THE ADIPIC ACID ENHANCED LIMESTONE FGD PROCESS (JULY 1981)

    The proceedings document presentations made during an EPA-sponsored industry briefing, July 15, 1981, in Springfield, MO. The briefing dealt with the status of EPA's research activities on the adipic-acid-enhanced limestone flue gas desulfurization (FGD) process. Subjects covered...

  13. Preliminary study of the influence of CO2 extraction conditions on the ester, aldehyde, ketone and hydrocarbon content of grape bagasses from jam production

    J. Santos

    2007-12-01

    Full Text Available The main objective of this work was to assess the influence of temperature and pressure on the chemical characteristics of the essential oil obtained from CO2 extraction of grape bagasses in the production of jam. The experiments were performed in a laboratory-scale unit, where the effect of temperature (290 and 303 K and pressure (15 and 25 Mpa was investigated in terms of liquid yield and chemical composition of the extracts. The CO2 mass flow rate was kept within a range of 2.5 to 3.0 g/min. The instrumental analysis was performed by gas chromatography with a mass spectrometer detector (GC-MS. The extraction conditions investigated in this work had no significant influence on the mass of essencial oil extracted. The main compounds identified in the extracts by the GC-MS spectra library (match quality higher tan 90% were octadecane, dihydroxy ergostene-dione and phenylethyl n-decanoate when the temperature was increased from 290 to 303 K. Heptanal, ethyl ester of decosonoic acid and hexatriacontane were the individual compounds with the greatest increase in the chromatographic peak area when the pressure was increased from 15 to 25 Mpa. The most important class of compounds were hydrocarbons at 303 K and 15 MPa and were ketones and aldehydes at 25 Mpa and 290 K.

  14. Synthesis and structural characterization of zirconium phosphate adipate dimethyl sulphoxide: A new lambda-type organic-inorganic layered material

    Hussein Alhendawi

    2014-07-01

    −Zirconium phosphate adipate dimethyl sulphoxide, -ZrPO4(OOC-(CH2)4-COOH)(CH3)2SO, is prepared by means of topotactic anion exchange of the chloride ligand of -Zirconium phosphate, -ZrPO4Cl(CH3)2SO, with adipate. The samples are characterized by thermal analyses, X-ray diffractometry and FT-IR spectrophotometry. The used analysis approaches provide strong evidence that the chloride monovalent anions of -Zirconium phosphate are completely exchanged with the carboxylate groups of the adipate monoanionic ligands. Moreover, the adipate ligands replace the chloride anions in a 1:1 stoichiometry. In this case the formula of the derivative should contain the monoanionic adipate fragment: (OOC-(CH2)4-COOH). This formula is in agreement with TGA and elemental analysis. With respect to intercalation properties, the synthesized adipate-solid phase has a higher acidic character and a larger gallery height in comparison to the pristine -Zirconium phosphate (1.47, 1.02 nm, respectively). Therefore, this material is expected to be a suitable host for intercalation of huge basic guests.

  15. NF EN 14107. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the phosphorus content by high frequency induced plasma emission spectroscopy (ICP method); NF EN 14107. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en phosphore par spectrometrie d'emission de plasma induit par haute frequence (methode ICP)

    NONE

    2003-07-01

    This European standard specifies a method of phosphorus content dosimetry in fatty acids methylic esters (FAME) using high frequency induced plasma emission spectroscopy and for concentrations comprised between 4 mg/kg and 20 mg/kg. The objective of this method is to evaluate the quality of the FAMEs in terms of trans-esterification of their by-products content, such as phosphorus, which can change the fuel combustion properties. This method involves dangerous compounds, operations and equipments which are not considered in the text of the standard. (J.S.)

  16. Catalytic routes towards acrylic acid, adipic acid and epsilon-caprolactam starting from biorenewables

    Beerthuis, R.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    The majority of bulk chemicals are derived from crude oil, but the move to biorenewable resources is gaining both societal and commercial interest. Reviewing this transition, we first summarise the types of today's biomass sources and their economical relevance. Then, we assess the biobased productions of three important bulk chemicals: acrylic acid, adipic acid and epsilon-caprolactam. These are the key monomers for high-end polymers (polyacrylates, nylon 6.6 and nylon 6, respectively) and a...

  17. 76 FR 7703 - 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4-Butanediol, Adipic Acid, and...

    2011-02-11

    ...), minimum number average molecular weight (in amu) 30,000, when used as an inert ingredient (component of... average molecular weight (MW) greater than or equal to 10,000 daltons. Additionally, in order to meet the... nontoxic to earthworms. Due to its large size (minimum number average molecular weight 30,000 amu) and...

  18. Preparation and characterization of crosslinked poly(butylene adipate-co-terephthalate)/polyhedral oligomeric silsesquioxane nanocomposite by electron beam irradiation

    The electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate) (PBAT)/polyhedral oligomeric silsesquioxane (POSS) nanocomposites was investigated in this study. PBAT/POSS nanocomposites prepared by a solution blending with various compositions were crosslinked by electron beam irradiation at various absorbed doses ranging from 20 to 200 kGy and their properties were characterized in terms of their degree of crosslinking, morphology, thermal and mechanical properties, and biodegradability. The results of the degree of crosslinking measurements revealed that PBAT/POSS nanocomposites were more effectively crosslinked than the pure PBAT and that the degree of crosslinking was dependent on the absorbed dose and POSS content. From the results of the FE-SEM and EDX analyses, the POSS was found to be uniformly dispersed in the PBAT matrix. Based on the results of the UTM, DMA, and TMA, the crosslinked PBAT/POSS nanocomposites exhibited much higher thermal and mechanical properties compared to those of the pure PBAT. - Highlights: ► Crosslinked PBAT/POSS nanocomposites were prepared by electron beam irradiation. ► The POSS as a nanofillers was homogeneously dispersed in the PBAT matrix. ► The crosslinked nanocomposites exhibited improved thermal and mechanical properties.

  19. Content

    Keiding, Tina Bering

    Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007; R...... strategy is theoretically based on systems theory as formulated by Niklas Luhmann (Luhmann, 1995; 2002) and on own work, where. Luhmann’s general ideas and concepts of the educational system are transposed into a didactical framework (Keiding, 2005,2007,2008).......Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007......, is subordinating content to methods as seen in modern didactics, hereby transforming content to a medium for achievement of learning-to-learn skills rather than something valuable in its own right. At the level of general didactics quite few attempts have been made to formulate criteria and...

  20. 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.

    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

  1. Pepper protein phosphatase type 2C, CaADIP1 and its interacting partner CaRLP1 antagonistically regulate ABA signalling and drought response.

    Lim, Chae Woo; Lee, Sung Chul

    2016-07-01

    Abscisic acid (ABA) is a key phytohormone that regulates plant growth and developmental processes, including seed germination and stomatal closing. Here, we report the identification and functional characterization of a novel type 2C protein phosphatase, CaADIP1 (Capsicum annuum ABA and Drought-Induced Protein phosphatase 1). The expression of CaADIP1 was induced in pepper leaves by ABA, drought and NaCl treatments. Arabidopsis plants overexpressing CaADIP1 (CaADIP1-OX) exhibited an ABA-hyposensitive and drought-susceptible phenotype. We used a yeast two-hybrid screening assay to identify CaRLP1 (Capsicum annuum RCAR-Like Protein 1), which interacts with CaADIP1 in the cytoplasm and nucleus. In contrast to CaADIP1-OX plants, CaRLP1-OX plants displayed an ABA-hypersensitive and drought-tolerant phenotype, which was characterized by low levels of transpirational water loss and increased expression of stress-responsive genes relative to those of wild-type plants. In CaADIP1-OX/CaRLP1-OX double transgenic plants, ectopic expression of the CaRLP1 gene led to strong suppression of CaADIP1-induced ABA hyposensitivity during the germinative and post-germinative stages, indicating that CaADIP1 and CaRLP1 act in the same signalling pathway and CaADIP1 functions downstream of CaRLP1. Our results indicate that CaADIP1 and its interacting partner CaRLP1 antagonistically regulate the ABA-dependent defense signalling response to drought stress. PMID:26825039

  2. CONTENTS

    2012-01-01

    The Development and Evolution of the Idea of the Mandate of Heaven in the Zhou Dynasty The changes in the idea of Mandate of Heaven during the Shang and Zhou dynasties are of great significance in the course of the development of traditional Chinese culture. The quickening and awakening of the humanistic spirit was not the entire content of the Zhou idea of Mandate of Heaven. In the process of annihilating the Shang dynasty and setting up their state, the Zhou propagated the idea of the Mandate of Heaven out of practical needs. Their idea of the Mandate of Heaven was not very different from that of the Shang. From the Western Zhou on, the Zhou idea of Mandate of Heaven by no means developed in a linear way along a rational track. The intermingling of rationality and irrationality and of awakening and non-awakening remained the overall state of the Zhou intellectual superstructure after their "spiritual awakening".

  3. The liquid–liquid coexistence curves of {x dimethyl adipate + (1 − x) n-hexane} and {x dimethyl adipate + (1 − x) n-heptane} in the critical region

    Highlights: ► Coexistence curves of (dimethyl adipate + n-hexane) (+n-heptane) were measured. ► The critical exponent β are consistent with the 3D-Ising value. ► The asymmetry of the coexistence curves were discussed by complete scaling theory. - Abstract: The liquid–liquid coexistence curves for (dimethyl adipate + n-hexane), (dimethyl adipate + n-heptane) have been measured, from which the critical amplitudes and the critical exponents are deduced. The critical exponent β corresponding to the coexistence curves are consistent with the 3D-Ising value. The experimental results have also been analyzed to determine the critical amplitudes of Wegner-correction terms when β and Δ are fixed at their theoretical values, and to examine the asymmetry of the diameters for the coexistence curves.

  4. Synthesis and characterization of aliphatic polyesters from glycerol, by-product of biodiesel production, and adipic acid

    Michel de Meireles Brioude

    2007-12-01

    Full Text Available In the present work, polyesters were prepared from the polycondensation between glycerol and adipic acid using dibutyltin dilaurate as catalyst. Three glycerol: adipic acid molar ratio were used for the bulk polymerization namely: 2:2; 2:3 and 2:4. FTIR confirmed the esterification of glycerol by the acid for all the polymers. DSC and XRD indicated no crystallinity for all the polymers. The morphology of the materials are characterized by globular structure, which may suggest compositional fluctuations throughout the samples.

  5. Determination of Mass Spectrometric Sensitivity of Different Metalloporphyrin Esters Relative to Porphyrin Ester

    Larsen, Elfinn; Egsgaard, Helge; Møller, J.;

    1977-01-01

    Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal...... complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro......-prophyrin permethylester were all found to have the same molecular ion sensitivities as their metal-free porphyrin ester. The relative metalloporphyrin ester content in a sample of porphyrin ester was thus obtained directly as the integrated ion current ratios of the normalized molecular ions. The preparation of...

  6. Engineering a Polyketide Synthase for In Vitro Production of Adipic Acid.

    Hagen, Andrew; Poust, Sean; Rond, Tristan de; Fortman, Jeffrey L; Katz, Leonard; Petzold, Christopher J; Keasling, Jay D

    2016-01-15

    Polyketides have enormous structural diversity, yet polyketide synthases (PKSs) have thus far been engineered to produce only drug candidates or derivatives thereof. Thousands of other molecules, including commodity and specialty chemicals, could be synthesized using PKSs if composing hybrid PKSs from well-characterized parts derived from natural PKSs was more efficient. Here, using modern mass spectrometry techniques as an essential part of the design-build-test cycle, we engineered a chimeric PKS to enable production one of the most widely used commodity chemicals, adipic acid. To accomplish this, we introduced heterologous reductive domains from various PKS clusters into the borrelidin PKS' first extension module, which we previously showed produces a 3-hydroxy-adipoyl intermediate when coincubated with the loading module and a succinyl-CoA starter unit. Acyl-ACP intermediate analysis revealed an unexpected bottleneck at the dehydration step, which was overcome by introduction of a carboxyacyl-processing dehydratase domain. Appending a thioesterase to the hybrid PKS enabled the production of free adipic acid. Using acyl-intermediate based techniques to "debug" PKSs as described here, it should one day be possible to engineer chimeric PKSs to produce a variety of existing commodity and specialty chemicals, as well as thousands of chemicals that are difficult to produce from petroleum feedstocks using traditional synthetic chemistry. PMID:26501439

  7. The influence of pressure on the photoluminescence properties of a terbium-adipate framework

    The influence of pressure (over the 0–4.7 GPa range) on the photoluminescence emissions and crystal structure of the known 3D terbium-adipate metal-organic framework material Tb-GWMOF6 has been evaluated by high-pressure single-crystal X-ray diffraction and spectroscopic techniques. The results from this study show that this complex lanthanide framework structure undergoes three phase transitions within the 0–4 GPa pressure range that involve alterations in the number of symmetry independent Tb3+ ion sites within the crystal lattice. These pressure induced modifications to the structure of Tb-GWMOF6 lead to pronounced changes in the profiles of the 5D4→7F5 emission spectra of this complex. - Graphical abstract: The influence of pressure on the structure and photoluminescence emissions of a 3D terbium-adipate framework. - Highlights: • High-pressure luminescence spectra for a Tb framework were collected. • High-pressure single-crystal XRD experiments were conducted with the Tb Framework. • The framework undergoes two pressure-induced phase transitions. • The three phases of the material show different photoluminescence behaviour

  8. Electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate)

    Hwang, In-Tae; Jung, Chan-Hee; Kuk, In-Seol; Choi, Jae-Hak; Nho, Young-Chang

    2010-11-01

    Biodegradable poly(butylene adipate-co-terephthalate) (PBAT) was crosslinked by electron beam irradiation and their properties were investigated in this research. PBAT films prepared by a solution casting method were crosslinked by electron beam under various absorbed doses ranging 20-200 kGy and their properties were characterized by using a crosslinking degree measurement, a thermogravimetric analyzer (TGA), universal testing machine (UTM), dynamic mechanical analyzer (DMA), and thermal mechanical analyzer (TMA). The results of the crosslinking degree measurement revealed that the PBAT could be crosslinked by electron beam irradiation and its crosslinking degree was dependant on the absorbed dose. In addition, the results of the UTM, DMA, TMA, and TGA analyses revealed that the thermal and mechanical properties of the crosslinked PBS was much improved in comparison to those of the control PBAT.

  9. Influence of Teflon substrate on crystallization and enzymatic degradation of polymorphic poly(butylene adipate)

    Ning, Zhenbo; Nielsen, Ronnie Bo Højstrup; Zhao, Lifen;

    2014-01-01

    Oriented and non-oriented Teflon films, which were found to have the same crystalline structure, but different surface morphologies, were used to sandwich poly(butylene adipate) (PBA) films during isothermal crystallization. It was found that both the Teflon surface structure and the PBA...... polymorphic structure are the determining factors to induce epitaxial crystallization. The oriented Teflon film was able to induce epitaxial crystallization of PBA alpha crystal, while the non-oriented Teflon did not induce any epitaxial crystallization of PBA. Epitaxial crystallization did not occurred for...... PBA beta crystals between neither the oriented nor the non-oriented Teflon films. The enzymatic degradation rate of PBA films was not determined by the epitaxial crystallization, in fact it was still dependent on the polymorphic crystal structure of PBA. The morphological changes of PBA films after...

  10. Electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate)

    Biodegradable poly(butylene adipate-co-terephthalate) (PBAT) was crosslinked by electron beam irradiation and their properties were investigated in this research. PBAT films prepared by a solution casting method were crosslinked by electron beam under various absorbed doses ranging 20-200 kGy and their properties were characterized by using a crosslinking degree measurement, a thermogravimetric analyzer (TGA), universal testing machine (UTM), dynamic mechanical analyzer (DMA), and thermal mechanical analyzer (TMA). The results of the crosslinking degree measurement revealed that the PBAT could be crosslinked by electron beam irradiation and its crosslinking degree was dependant on the absorbed dose. In addition, the results of the UTM, DMA, TMA, and TGA analyses revealed that the thermal and mechanical properties of the crosslinked PBS was much improved in comparison to those of the control PBAT.

  11. Construction of two Cd(II) complexes by flexible adipic acid plus 2-((benzoimidazol-yl)methyl)-1H-tetrazole ligand

    Duan, Wanlu; Zhang, Yuhong; Wang, Xiuxiu; Meng, Xiangru

    2015-10-01

    Two new complexes with the formulas [Cd(bimt)(adi)]n (1) and {[Cd(bimt)(adi)0.5Br]·H2O}n (2) were synthesized through reactions of 2-((benzoimidazol-yl)methyl)-1H-tetrazole (bimt) with Cd(II) salts in the presence of adipic acid (H2adi). Single crystal X-ray analysis reveals that complex 1 shows a 1D chain structure in which adipate ligand coordinates to Cd(II) ions with μ3-bridging mode. Complex 2 displays a 2D layer structure with 4-connected (44·62) topology in which adipate ligand coordinates to Cd(II) ions with μ2-bridging mode. These results reveal that the versatile coordination modes of adipate ligands play an important role in controlling the structures of the complexes. In addition, their IR spectra, element analyses, PXRD patterns and luminescent properties are investigated.

  12. Apomorphine and its esters

    Borkar, Nrupa; Chen, Zhizhong; Saaby, Lasse;

    2016-01-01

    Oral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson's disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine...

  13. cis,cis-Muconic Acid: Separation and Catalysis to Bio-Adipic Acid for Nylon-6,6 Polymerization

    Vardon, Derek R.; Rorrer, Nicholas A.; Salvachua, Davinia; Settle, Amy E.; Johnson, Christopher W.; Menart, Martin J.; Cleveland, Nicholas S.; Ciesielski, Peter N.; Steirer, K. Xerxes; Dorgan, John R.; Beckham, Gregg T.

    2016-06-07

    cis,cis-Muconic acid is a polyunsaturated dicarboxylic acid that can be produced renewably via the biological conversion of sugars and lignin-derived aromatic compounds. Subsequently, muconic acid can be catalytically converted to adipic acid -- the most commercially significant dicarboxylic acid manufactured from petroleum. Nylon-6,6 is the major industrial application for adipic acid, consuming 85% of market demand; however, high purity adipic acid (99.8%) is required for polymer synthesis. As such, process technologies are needed to effectively separate and catalytically transform biologically derived muconic acid to adipic acid in high purity over stable catalytic materials. To that end, this study: (1) demonstrates bioreactor production of muconate at 34.5 g L-1 in an engineered strain of Pseudomonas putida KT2440, (2) examines the staged recovery of muconic acid from culture media, (3) screens platinum group metals (e.g., Pd, Pt, Rh, Ru) for activity and leaching stability on activated carbon (AC) and silica supports, (4) evaluates the time-on-stream performance of Rh/AC in a trickle bed reactor, and (5) demonstrates the polymerization of bio-adipic acid to nylon-6,6. Separation experiments confirmed AC effectively removed broth color compounds, but subsequent pH/temperature shift crystallization resulted in significant levels of Na, P, K, S and N in the crystallized product. Ethanol dissolution of muconic acid precipitated bulk salts, achieving a purity of 99.8%. Batch catalysis screening reactions determined that Rh and Pd were both highly active compared to Pt and Ru, but Pd leached significantly (1-9%) from both AC and silica supports. Testing of Rh/AC in a continuous trickle bed reactor for 100 h confirmed stable performance after 24 h, although organic adsorption resulted in reduced steady-state activity. Lastly, polymerization of bio-adipic acid with hexamethyldiamine produced nylon-6,6 with comparable properties to its petrochemical counterpart

  14. Lubricants based on synthetic esters; Schmierstoffe auf Basis synthetischer Ester

    Fahl, J. [Forschung und Entwicklung Kaeltemaschinenoele, Fuchs DEA Schmierstoffe GmbH, Hamburg (Germany)

    2000-07-01

    This article describes the synthetic esters that are being used in refrigeration applications that use chlorine-free working fluids. The chemical basics involved in these high-performance lubricants, their manufacture and their lubricating properties are looked at in detail. The history of their development from their use as machining oils, lubricants for weapons and two-stroke engines through to turbine lubricants and as hydraulic oil in aeronautics is reviewed. Modern neopentyl-polyol esters used in refrigeration applications are described. Further, the chemical structures and applications of complex esters, carbonate esters, aromatic and silicate esters are looked at.

  15. Short-chain aliphatic ester synthesis using Thermobifida fusca cutinase.

    Su, Lingqia; Hong, Ruoyu; Guo, Xiaojie; Wu, Jing; Xia, Yongmei

    2016-09-01

    Short-chain aliphatic esters are commonly used as fruit flavorings in the food industry. In this study, Thermobifida fusca (T. fusca) cutinase was used for the synthesis of aliphatic esters, and the maximum yield of ethyl caproate reached 99.2% at a cutinase concentration of 50U/ml, 40°C, and water content of 0.5%, representing the highest ester yield to date. The cutinase-catalyzed esterification displayed strong tolerance for water content (up to 8%) and acid concentration (up to 0.8M). At substrate concentrations ⩽0.8M, the ester yield remained above 80%. Moreover, ester yields of more than 98% and 95% were achieved for acids of C3-C8 and alcohols of C1-C6, respectively, indicating extensive chain length selectivity of the cutinase. These results demonstrate the superior ability of T. fusca cutinase to catalyze the synthesis of short-chain esters. This study provides the basis for industrial production of short-chain esters using T. fusca cutinase. PMID:27041308

  16. Green process for adipic acid synthesis: oxidation by hydrogen peroxide in water micromelusions using Benzalkonium Chloride C12-14 surfactant

    Lesage, Geoffroy; Quesada-Peñate, Isariebel; Cognet, Patrick; Poux, Martine

    2012-01-01

    Adipic acid was synthesized by the oxidation of cyclohexene using 30% hydrogen peroxide in a microemulsion in the presence of sodium tungstate as catalyst. The proposed green process is environmentally friendly since catalyst and surfactant are recycled and pure adipic acid is produced in high yield (70% to 79%). Microemulsions are used as a “green solvent” and give a better contact between the phases. Alkyldimethylbenzylammonium chloride (C12-C14) was used as a surfactant for the generation ...

  17. Synthesis and in vitro bio degradation of poly(ethylene adipate- co-D,L-lactic acid copolymers (PLEA

    Bakouri Hichem

    2014-09-01

    Full Text Available The present research mainly focused on the synthesis and study of bio degradation of poly (ethylene adipate-co-D,L-lactic acid. PLEA were prepared via ring opening polymerization from D,L-lactide and poly(ethylene adipate. PLEA was characterized by 1H NMR spectra and DSC; results showed that those properties showed high dependence on its composition.In vitro degradation behaviors of PLEA have been systematically investigated up to 12 weeks in phosphate buffer saline solution at 37 °C. The weight and polymer molecular weight were measured as a function of degradation time. Bacterial degradation was completed by investigating the physico-chemical properties using spectroscopy FTIR and DSC.

  18. NF EN 14110. July 2003. Fatty compounds derived products. Fatty acids methylic esters (FAME). Determination of the methanol content; NF EN 14110. Juillet 2003. Produits derives des corps gras. Esters methyliques d'acides gras (EMAG). Determination de la teneur en methanol

    NONE

    2003-07-01

    This European standard describes a method of methanol dosimetry in fatty acids methylic esters (FAME) which can be applied to gas-oil and domestic fuel oil. This method is applicable over a large spectrum of methanol concentrations comprised between 0.01% (m/m) and 0.5% (m/m). It is not applicable to FAME mixtures containing low boiling point compounds. (J.S.)

  19. Influence of end groups in hyperbranched polyesters used as modifiers in the characteristics of epoxy thermosets cured by adipic dihydrazide

    Serra, A; A. M. Tomuta; X. Ramis; S. De la Flor

    2013-01-01

    Mixtures of diglycidylether of bisphenol A (DGEBA) resin and different ratios of aliphatic-aromatic hyperbranched polyester (HBP) were cured by a latent curing agent, adipic dihydrazide (AH). The HBPs prepared have hydroxyl groups or 10-undecenoyl or allyl groups as chain ends. The curing mixtures were investigated by differential scanning calorimetry (DSC) to study the curing process and to evaluate the kinetic parameters of the different formulations. These studies suggest that HBPs decreas...

  20. Langzeitevaluation eines psychologischen Trainings für adipöse Kinder und ihre Eltern (TAKE)

    Roth, Binia; Munsch, Simone; Meyer, Andrea H.

    2011-01-01

    Verhaltenstherapeutische Eltern-Kind-Programme haben bisher die besten Effekte bei der Behandlung kindlicher Adipositas gezeigt. Mit TAKE (Training adipöser Kinder und ihrer Eltern) stellen wir eine psychologiebasierte Behandlung vor, die nicht nur Bewegung, Ernährung und Essverhalten als Elemente einschließt, sondern auch psychische Faktoren wie Selbstwertgefühl, Körperbild, soziale Kompetenzen und Hänseleien sowohl mit den Eltern als auch mit den Kindern behandelt. Aktuell liegen die Langze...

  1. Crystal engineering of analogous and homologous organic compounds: hydrogen bonding patterns in trimethoprim hydrogen phthalate and trimethoprim hydrogen adipate

    Rychlewska Urszula; Francis Savarimuthu; Muthiah Packianathan; Warżajtis Beata

    2006-01-01

    Abstract Background Trimethoprim [2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidine] is an antifolate drug. It selectively inhibits the bacterial dihydrofolate reductase (DHFR) enzyme. Results In the crystal structures of trimethoprim (TMP)-hydrogen phthalate (1) and trimethoprim-hydrogen adipate (2), one of the N atoms of the pyrimidine ring is protonated and it interacts with the deprotonated carboxylate oxygens through a pair of nearly parallel N-H...O hydrogen bonds to form a fork-like ...

  2. Poly(lactide)-g-poly(butylene succinate-co-adipate) with High Crystallization Capacity and Migration Resistance

    Xi Yang; Huan Xu; Karin Odelius; Minna Hakkarainen

    2016-01-01

    Plasticized polylactide (PLA) with increased crystallization ability and prolonged life-span in practical applications due to the minimal plasticizer migration was prepared. Branched plasticized PLA was successfully obtained by coupling poly(butylene succinate-co-adipate) (PBSA) to crotonic acid (CA) functionalized PLA. The plasticization behavior of PBSA coupled PLA (PLA-CA-PBSA) and its counterpart PBSA blended PLA (PLA/PBSA) were fully elucidated. For both PLA-CA-PBSA and PLA/PBSA, a decre...

  3. Valyl benzyl ester chloride

    Grzegorz Dutkiewicz

    2010-02-01

    Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

  4. Dispersion study of nanofibrillated cellulose based poly(butylene adipate-co-terephthalate) composites.

    Mukherjee, Tapasi; Czaka, Michael; Kao, Nhol; Gupta, Rahul K; Choi, Hyoung Jin; Bhattacharya, Sati

    2014-02-15

    The production of lower cost bionanocomposites based on nanofibrillated cellulose (NFC) is a promising source to develop the next generation of light weight and high performance materials for a variety of defense, infrastructure and energy applications. In this study, a series of bio-nanocomposites were developed by reinforcing NFC from regenerated wood fiber into poly(butylene adipate-co-terephthalate) (PBAT) by injection molding. The incorporation of NFC in PBAT matrix (0.2-1 wt%) increased the storage modulus (G') and dynamic viscosity (η') as revealed by shear rheology, indicating a percolation threshold around 0.2-0.5 wt% region. DSC analysis showed similar trends with slight improvement of glass transition (Tg) and crystallization temperature (Tc). Percentage crystallinity, as calculated from heat of fusion equation and taking into account 100% crystallized PBAT data improved in overall. This is a fundamental study aimed at understanding the morphological, rheological and thermal evaluation of such nanocomposites for an improved dispersion of NFC as filler in the matrix. PMID:24507316

  5. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay.

    Chen, Jung-Hung; Yang, Ming-Chien

    2015-01-01

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. PMID:25491991

  6. Method of making alkyl esters

    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.

  7. Occurrence of fatty acid esters of 3-MCPD, 2-MCPD and glycidol in infant formula.

    Wöhrlin, Friederike; Fry, Hildburg; Lahrssen-Wiederholt, Monika; Preiß-Weigert, Angelika

    2015-01-01

    The discovery of fatty acid esters of monochloropropanediol (MCPD) and glycidol generated during the refinement process in vegetable fats and oils caused concerns about possible adverse health effects. As these fats are components of infant formula, the current investigation of the MCPD and glycidyl ester contents in infant formula was necessary to update the data for risk assessment purposes. For the analysis of 3-MCPD, 2-MCPD and glycidyl esters in infant formula, an existing method for fats and oils had to be modified and validated. The fat fraction containing MCPD and glycidyl esters was extracted from infant formula by accelerated solvent extraction (ASE). The extracted fat was then analysed according to an established method for fats and oils. Glycidyl esters are converted to monobrompropanediol (3-MBPD) esters, MCPD and 3-MBPD esters hydrolysed subsequently and after derivatisation detected by GC-MS. Seven different products of infant formula, covering two types and five lots each, altogether 70 samples, were bought in retail markets and analysed. In all samples, 3-MCPD and glycidyl esters could be detected. Both 3-MCPD and glycidyl esters' concentration levels were found to be lower in comparison with earlier investigations described in the literature. The occurrence of 2-MCPD esters in infant formula was investigated for the first time and revealed concentrations about half of 3-MCPD ester concentrations. PMID:26179516

  8. Data on synthesis of oligomeric and polymeric poly(butylene adipate-co-butylene terephthalate model substrates for the investigation of enzymatic hydrolysis

    Veronika Perz

    2016-06-01

    Full Text Available The aliphatic-aromatic copolyester poly(butylene adipate-co-butylene terephthalate (PBAT, also known as ecoflex, contains adipic acid, 1,4-butanediol and terephthalic acid and is proven to be compostable [1–3]. We describe here data for the synthesis and analysis of poly(butylene adipate-co-butylene terephthalate variants with different adipic acid:terephatalic acid ratios and 6 oligomeric PBAT model substrates. Data for the synthesis of the following oligomeric model substrates are described: mono(4-hydroxybutyl terephthalate (BTa, bis(4-(hexanoyloxybutyl terephthalate (HaBTaBHa, bis(4-(decanoyloxybutyl terephthalate (DaBTaBDa, bis(4-(tetradecanoyloxybutyl terephthalate (TdaBTaBTda, bis(4-hydroxyhexyl terephthalate (HTaH and bis(4-(benzoyloxybutyl terephthalate (BaBTaBBa. Polymeric PBAT variants were synthesized with adipic acid:terephatalic acid ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. These polymeric and oligomeric substances were used as ecoflex model substrates in enzymatic hydrolysis experiments in the article “Substrate specificities of cutinases on aliphatic-aromatic polyesters and on their model substrates” [4].

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

    Chisnell, J. R.

    1984-01-01

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

  10. Effect of fiber esterification on fundamental properties of oil palm empty fruit bunch fiber/poly(butylene adipate-co-terephthalate) biocomposites.

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites' thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens. PMID:22408394

  11. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate Biocomposites

    Mohamad Zaki AB Rahman

    2012-01-01

    Full Text Available A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate (PBAT, which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB fiber was successfully done by grafting succinic anhydride (SAH onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24% compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA/differential thermogravimetric (DTG thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.

  12. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate) Biocomposites

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki AB

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens. PMID:22408394

  13. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. - Highlights: • Nanocomposites of PBAT and clay nanoparticles were prepared via melting blending. • Maleated PBAT/organoclays exhibited higher Young's moduli than neat PBAT/neat MMT. • The enzymatic degradation of PBAT composites was improved by maleation. • Maleation caused little effect on the photodegradation of PBAT. • Organoclays retarded the permeation of water vapor through PBAT composites

  14. Effect of Anodic Alumina Oxide Pore Diameter on the Crystallization of Poly(butylene adipate).

    Sun, Xiaoli; Fang, Qunqun; Li, Huihui; Ren, Zhongjie; Yan, Shouke

    2016-04-01

    Poly(butylene adipate) (PBA) was infiltrated into the anodic alumina oxide (AAO) templates with the pore diameter of around 30, 70, and 100 nm and PBA nanotubes with different diameters were prepared. The crystallization and phase transition behavior of the obtained PBA nanotubes capped in the nanopores have been explored by using X-ray diffraction and differential scanning calorimetry. Only α-PBA crystals form in the bulk sample during nonisothermal crystallization. By contrast, predominant β-PBA crystals form in the AAO templates. The β-PBA crystals formed in the nanopores with pore diameter less than 70 nm prefer to adopt an orientation with their b-axis parallel to the long axis of the pore. During the melt recrystallization, it was found that the critical temperature (Tβ), below which pure β-crystals form, is 20 °C for bulk PBA. It drops down significantly with the pore diameter for the PBA in the AAO template. Moreover, the β-crystals in the porous template exhibit larger lattice parameters compared with the bulk crystals. By monitoring the change of β-crystals in the heating process, it was found that β-crystals in the AAO template with the pore diameter of 30 nm (D30) melt directly while the β-crystals transform to α-crystals in the template with the pore diameter of 100 nm (D100). The intensity of (020) Bragg peak of β-crystals decreases at a similar rate in both D30 and D100 but disappears at a relatively lower temperature in D30. On the other hand, the β(110) peak intensity of β-PBA crystals formed in the D100 template decreases first at slower rate before α crystals appear, and then at a faster rate once the β to α phase transition takes place. PMID:27008378

  15. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay

    Chen, Jung-Hung [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Yang, Ming-Chien, E-mail: myang@mail.ntust.edu.tw [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2015-01-01

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. - Highlights: • Nanocomposites of PBAT and clay nanoparticles were prepared via melting blending. • Maleated PBAT/organoclays exhibited higher Young's moduli than neat PBAT/neat MMT. • The enzymatic degradation of PBAT composites was improved by maleation. • Maleation caused little effect on the photodegradation of PBAT. • Organoclays retarded the permeation of water vapor through PBAT composites.

  16. Design, Synthesis and Characterisation of Novel Biodegradable Aliphatic Copolyesters- Poly(ethylene sebacate-co-butylene succinate and Poly(ethylene sebacate-co-butylene adipate

    L. SOWBAGYALAKSHMI PRABHA

    2012-12-01

    Full Text Available Synthesis of novel aliphatic biodegradable copolyesters namely Poly (ethylene sebacate-co-butylene succinate and Poly (ethylene sebacate-co-butylene adipate were carried out using Poly (butylene Succinate, Poly (Butylene Adipate and Poly (Ethylene Sebacate in presence of Poly Phosphoric acid. Synthesis of Poly (Butylene Succinate, Poly (Butylene Adipate and Poly (Ethylene Sebacate were carried out using respective diols and diacids in presence of titanium tetrabutoxide as catalyst. Newly synthesized copolyesters were characterized by solubility studies, viscosity measurements, thermal analysis, IR Spectroscopy and Nuclear Magnetic Resonance Spectroscopy (1H-NMR and 13C-NMR. The characteristic peaks present in the homopolyesters were recorded in the copolymers as well. DSC analysis of the copolyesters showed multiple melting peaks, while increase of methylene units in the di-acid decreased the Tg.

  17. Densities, refractive indices and viscosities of the binary mixtures of dimethyl phthalate or dimethyl adipate with tetrahydrofuran

    Knežević-Stevanović Anđela B.

    2014-01-01

    Full Text Available Densities, refractive indices and viscosities of the binary mixtures of dimethyl phthalate (or dimethyl adipate + tetrahydrofuran have been measured at eight temperatures (288.15 to 323.15 K and atmospheric pressure. All measurements were performed using an Anton Paar DMA 5000 digital vibrating-tube densimeter, Anton Paar RXA 156 refractometer and Anton Paar SVM 3000/G2 digital Stabinger viscometer, respectively. From the experimental densities, refractive indices and viscosities, the excess molar volumes, VE, deviations of refractive indices, DnD, and viscosity deviations, Dh, were calculated. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  18. Crystal engineering of analogous and homologous organic compounds: hydrogen bonding patterns in trimethoprim hydrogen phthalate and trimethoprim hydrogen adipate

    Rychlewska Urszula

    2006-04-01

    Full Text Available Abstract Background Trimethoprim [2,4-diamino-5-(3',4',5'-trimethoxybenzylpyrimidine] is an antifolate drug. It selectively inhibits the bacterial dihydrofolate reductase (DHFR enzyme. Results In the crystal structures of trimethoprim (TMP-hydrogen phthalate (1 and trimethoprim-hydrogen adipate (2, one of the N atoms of the pyrimidine ring is protonated and it interacts with the deprotonated carboxylate oxygens through a pair of nearly parallel N-H...O hydrogen bonds to form a fork-like interaction. In the compound 1, the pyrimidine moieties of the TMP cations are centrosymmetrically paired through a pair of N-H...N hydrogen bonds involving 4-amino group and the N (N3 atom of the pyrimidine rings to form a 8-membered hydrogen bonded ring [R22(8]. The 4-amino group of one TMP moiety and 2-amino group of another TMP moiety (both moieties are members of a base pair are bridged by the carbonyl oxygen of the phthalate moiety through N-H...O hydrogen bonds forming 8-membered hydrogen-bonded ring [R22(8]. The characteristic hydrogen-bonded rings observed in the structure aggregate into a supramolecular ladder consisting of a pair of chains, each of which is built up of alternate TMP and hydrogen phthalate ions. In the compound 2, two TMP cations and two hydrogen adipate anions are arranged about an inversion center so that the complementary DDAA (D = donor, A = acceptor arrays of quadruple hydrogen-bonding patterns are formed. The head-to-tail arrangement of the hydrogen adipate ions leads to a hydrogen-bonded supramolecular chain. From crystal engineering point of view, it is interesting to note that the compound 1 has a hydrogen-bonded network remarkably identical with its aliphatic analogue, trimethoprim hydrogen maleate. Similarly the compound 2, resembles its homolog trimethoprim hydrogen glutarate. Conclusion In the crystal structure of trimethoprim hydrogen phthalate, the hydrogen-bonded network is remarkably identical with its aliphatic

  19. The micromethod for determination of cholesterol, cholesteryl esters and phospholipids

    Okabe,Akinobu

    1974-12-01

    Full Text Available We examined the method for determining microquantities of lipids, including cholesterol, cholesteryl esters and phospholipids. A standard colorimetric procedure of cholesteryl esters was modified to accommodate a quantitative thin-layer chromatography. This method involved the following steps. (1 Separation of lipids by a thin-layer chromatography: Lipids were applied to Silica gel G plates. Plates were developed with petroleum ether-diethyl etheracetic acid (82: 18: 2, vIvIv. (2 Elution of cholesterol and its esters from scraped silica gel: After scraping the silica gel with adhered cholesterol and its esters, they were eluted with chloroform-methanol (4: 1, v,tv. In the case of phspholipids, the silica gel was calcified. (3 Colorimetric determination of the lipids: Cholesterol and its esters eluted from the silica gel were determined by the method of ZAK with ROSENTHAL'S color reagent directly and after saponification, respectively. Phospholipids were calculated from the phosphorous content determined by the method of KATES. On the basis of examination of recovery and analyses of lipids extracted from tissue, it was concluded that this method permitted a reliable estimation of microquantities of cholesterol, its esters and phospholipids from small amounts of biological materials.

  20. Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties

    Vavříková, Eva; Langschwager, Fanny; Jezova-Kalachova, Lubica; Křenková, Alena; Mikulová, Barbora; Kuzma, Marek; Křen, Vladimír; Valentová, Kateřina

    2016-01-01

    A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which accepted C5- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C2), malonic (C3), succinic (C4) and maleic (C4) acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin–Ciocalteau reagent (FCR) and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) than isoquercitrin; ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies. PMID:27338349

  1. Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties

    Eva Vavříková

    2016-06-01

    Full Text Available A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica, which accepted C5- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C2, malonic (C3, succinic (C4 and maleic (C4 acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin–Ciocalteau reagent (FCR and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl than isoquercitrin; ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies.

  2. Clean synthesis of adipic acid from cyclohexene in microemulsions with stearyl dimethyl benzyl ammonium chloride as surfactant: From the laboratory to bench scale

    Quesada-Peñate, Isariebel; Lesage, Geoffroy; Cognet, Patrick; Poux, Martine

    2012-01-01

    International audience Adipic acid, HOOC(CH2)4COOH, is a white crystalline solid used primarily in the manufacture of nylon-6,6 polyamide. In industry, adipic acid is mainly produced by oxidation of cyclohexane with air and nitric acidfollowing a homogeneous two-step route. However, this process leads to the formation of nitrous oxide, a greenhouse gas that has to be decomposed. The aim of this study was the development of a clean technology at pilot scale in order to obtain and recover pu...

  3. Sintesis Metil Ester Sulfonat Dari Asam Stearat Dan Metil Ester Sulfonat Dari Asam Oleat

    Samosir, Yustina

    2011-01-01

    The Synthesis of Methyl Ester Sulfonate (MES) from stearic acid and from oleic acid through the stages of esterification reaction, that are esterification from stearic acid and oleic acid that forms methyl ester stearic acid and methyl ester oleic acid next stage was sulfonating the two of methyl esters to form a methyl ester sulfonate stearic acid and methyl ester oleic acid sulfonate. Furthermore, both fatty acid methyl ester sulfonate is neutralized with NaOH to obtain sulfonate salt. ...

  4. Cholesteryl ester transfer activity. Localization and role in distribution of cholesteryl ester among lipoproteins in man.

    Groener, J E; Van Rozen, A J; Erkelens, D W

    1984-03-01

    The cholesteryl ester exchange/transfer protein is involved in the transport of cholesteryl ester from high density lipoproteins (HDL) to very low density lipoproteins (VLDL) and low density lipoproteins (LDL). Localization of cholesteryl ester transfer activity (CETA) in plasma was studied by measuring CETA in various delipidated fractions from a single step density ultracentrifugation gradient of plasma. CETA was measured in an in vitro system by calculating the exchange of cholesteryl ester in a standard mixture of [3H]CE-HDL and LDL. The method used for the delipidation of plasmas and fractions to be tested was critical. Optimal results were obtained by delipidation with diisopropylether-butanol (60: 40, v/v) at O degrees C. The bulk of CETA was detected in HDL3 (1.125 less than d less than 1.210 g/ml) when the lipoproteins were separated by single-step density gradient ultracentrifugation and in the 'lipoprotein-free' fraction (d greater than 1.250 g/ml) when the lipoproteins were separated by flotation ultracentrifugation including two washes. To determine whether CETA plays a role in the distribution of cholesteryl ester among the various lipoproteins, it was measured in whole plasma from normal and hyperlipidemic subjects. Plasma was delipidated before the assay in order to prevent bias due to variation of cholesterol content. CETA was higher in delipidated plasma of hyperlipidemic subjects (117.3 +/- 36.5 nmol CE/ml/h) than in delipidated plasma of normolipidemic controls (68.7 +/- 17.6 nmol CE/ml/h) (P less than 0.005). A positive correlation (r = 0.80, P less than 0.005) was found between CETA and (VLDL + LDL) cholesterol levels. A negative correlation (r = 0.57, P less than 0.05) existed between CETA and HDL cholesterol. This correlation was found both in the group as a whole and within the normal and the hyperlipidemic groups separately. The activity of the cholesteryl ester transfer appears to be a regulatory factor in the distribution of cholesteryl

  5. A green two-step process for adipic acid production from cyclohexene. A study on parameters affecting selectivity

    Cavani, F.; Macchia, F.; Pino, R.; Raabova, K.; Rozhko, E. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; Alini, S.; Accorinti, P.; Babini, G. [Radici Chimica SpA, Novara (Italy)

    2011-07-01

    In this paper, we report about the effect of reaction parameters on catalytic behavior in a twostep process aimed at the synthesis of adipic acid from cyclohexene. In the first step, cyclohexene reacts with an aqueous solution of hydrogen peroxide, under conditions leading to the formation of trans-1,2-cyclohexandiol as the prevailing product; the reaction is catalysed by tungstic acid, in the presence of phosphoric acid and of a PT agent. In the second step, 1,2-cyclohexandiol is oxidized with air, in the presence of an heterogeneous catalyst made of alumina-supported Ru(OH){sub 3}. This process is aimed at using the minimal amount of the costly hydrogen peroxide, since only one mole is theoretically needed per mole of cyclohexene. The first step afforded very high yield to the glycol, using only a slight excess of hydrogen peroxide. However, the second step turned out to be the more critical one, since the selectivity to adipic acid was very low because of the concomitant occurrence of several undesired side reactions. The latter were in part due to the reaction conditions used, which were necessary for the activation of cyclohexandiol. (orig.)

  6. Enhancement of mechanical and thermal properties of oil palm empty fruit bunch fiber poly(butylene adipate-co-terephtalate) biocomposites by matrix esterification using succinic anhydride.

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Bin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex™), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite. PMID:22343368

  7. Enhancement of Mechanical and Thermal Properties of Oil Palm Empty Fruit Bunch Fiber Poly(butylene adipate-co-terephtalate Biocomposites by Matrix Esterification Using Succinic Anhydride

    Samira Siyamak

    2012-02-01

    Full Text Available In this work, the oil palm empty fruit bunch (EFB fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate PBAT (EcoflexTM, as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites’ performance by chemical modification using succinic anhydride (SAH as a coupling agent in the presence and absence of dicumyl peroxide (DCP and benzoyl peroxide (BPO as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt % and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA. Scanning Electron Microscopy (SEM was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt % of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt % succinic anhydride (SAH and 1 (wt % dicumyl peroxide (DCP improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites’ spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite.

  8. Novel electrospun nanofibrous matrices prepared from poly(lactic acid)/poly(butylene adipate) blends for controlled release formulations of an anti-rheumatoid agent.

    Siafaka, Panoraia I; Barmbalexis, Panagiotis; Bikiaris, Dimitrios N

    2016-06-10

    In the present work, a series of novel formulations consisting of poly(lactic acid)/poly(butylene adipate) (PLA/PBAd) electrospun blends was examined as controlled release matrices for Leflunomide's active metabolite, Teriflunomide (TFL). The mixtures were prepared using different ratios of PLA and PBAd in order to produce nanofibrous matrices with different characteristics. Miscibility studies of the blended polymeric fibers were performed through differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). Hydrolytic degradation in the prepared fibers was evaluated at 37°C using a phosphate buffered saline solution. Different concentrations of (TFL) (5, 10, 15wt.%) were incorporated into nanofibers for examining the drug release behavior in simulated body fluids (SBF), at 37°C. The drug-loaded nanofibrous formulations were further characterized by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, DSC and XRD. Gel permeation chromatography (GPC) analysis was used to evaluate the mechanism of TFL release. Artificial neural networks (ANN) and multi-linear-regression (MLR) models were used to evaluate the effect of % content of PBAd (X1) and TFL (X2) on an initial burst effect and a dissolution behavior. It was found that PLA/PBAd nanofibers have different diameters depending on the ratio of used polyesters and added drug. TFL was incorporated in an amorphous form inside the polymeric nanofibers. In vitro release studies reveal that a drug release behavior is correlated with the size of the nanofibers, drug loading and matrix degradation after a specific time. ANN dissolution modeling showed increased correlation efficacy compared to MLR. PMID:27039136

  9. Effect of Naphthalene, Butylated Hydroxytoluene, Dioctyl Phthalate, and Adipic Dioctyl Ester, Chemicals Found in the Nests of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae) on a Saprophytic Mucor sp.

    Fungi are commonly found associated with termites and their nests. Four chemicals that have been isolated from the nests of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were evaluated to determine their effect on a common nest fungus, a saprophytic Mucor sp. Butylated hydroxyto...

  10. Effects of Low-Ester Pectin on Wheat Dough's Physical Properties Detected by Rheological Method

    Peilong Xu; Na Na; Qing Lin

    2013-01-01

    The study examined the influence of low-ester pectin on the rheological property of wheat dough through capillary rheological method. The experimental results showed that the more the content of low-ester pectin in wheat dough, the less viscosity of the dough, meanwhile, the higher of the dough strength, the weaker the maximum drawing force endured by the dough. Therefore, the content of low-ester pectin had a direct impact on gluten index of the dough, namely, the stability and stirring resi...

  11. Synthesis of biocompatible poly(ε-caprolactone-block-poly(propylene adipate copolymers appropriate for drug nanoencapsulation in the form of core-shell nanoparticles

    Nanaki SG

    2011-11-01

    Full Text Available Stavroula G Nanaki1, Kostas Pantopoulos2, Dimitrios N Bikiaris11Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece; 2Lady Davis Institute for Medical Research and Department of Medicine, McGill University, Montreal, Quebec, CanadaAbstract: Poly(propylene adipate-block-poly(ε-caprolactone copolymers were synthesized using a combination of polycondensation and ring-opening polymerization of ε-caprolactone in the presence of poly(propylene adipate. Gel permeation chromatography was used for molecular weight determination, whereas hydrogen-1 nuclear magnetic resonance and carbon-13 nuclear magnetic resonance spectroscopy were employed for copolymer characterization and composition evaluation. The copolymers were found to be block while their composition was similar to the feeding ratio. They formed semicrystalline structures, while only poly(ε-caprolactone formed crystals, as shown by wide angle X-ray diffraction. Differential scanning calorimetry data suggest that the melting point and heat of fusion of copolymers decreased by increasing the poly(propylene adipate amount. The synthesized polymers exhibited low cytotoxicity and were used to encapsulate desferrioxamine, an iron-chelating drug. The desferrioxamine nanoparticles were self-assembled into core shell structures, had mean particle size <250 nm, and the drug remained in crystalline form. Further studies revealed that the dissolution rate was mainly related to the melting temperature, as well as to the degree of crystallinity of copolymers.Keywords: biocompatible polyesters, poly(ε-caprolactone, poly(propylene adipate, drug encapsulation, desferrioxamine

  12. Phosphorylation of Kraft fibers with phosphate esters.

    Shi, Ying; Belosinschi, Dan; Brouillette, François; Belfkira, Ahmed; Chabot, Bruno

    2014-06-15

    Phosphate esters, derived from two different long-chain aliphatic alcohols, were used as phosphorylating reagents for Kraft pulp fibers. High phosphorus contents and almost non-degraded fibers were obtained by following this pathway. The phosphorylation efficiency was influenced by the alkyl chain length of PEs since the phosphorus content in modified fibers was higher for the shorter chain reagent. Due to the heterogeneous reaction environment, the amount of grafted phosphorus was found to be almost three times higher at the surface than in the bulk of the fibers. Analyses also indicated that the phosphorus was bonded to fibers as a phosphate-like structure. Furthermore, the situation seemed to be different for the fiber surface where significant amounts of phosphorus were present in more complex structures like pyrophosphate or even oligo-phosphate. PMID:24721058

  13. Preferential enrichment of large-sized very low density lipoprotein populations with transferred cholesteryl esters

    The effect of lipid transfer proteins on the exchange and transfer of cholesteryl esters from rat plasma HDL2 to human very low (VLDL) and low density (LDL) lipoprotein populations was studied. The use of a combination of radiochemical and chemical methods allowed separate assessment of [3H]cholesteryl ester exchange and of cholesteryl ester transfer. VLDL-I was the preferred acceptor for transferred cholesteryl esters, followed by VLDL-II and VLDL-III. LDL did not acquire cholesteryl esters. The contribution of exchange of [3H]cholesteryl esters to total transfer was highest for LDL and decreased in reverse order along the VLDL density range. Inactivation of lecithin: cholesterol acyltransferase (LCAT) and heating the HDL2 for 60 min at 56 degrees C accelerated transfer and exchange of [3H]cholesteryl esters. Addition of lipid transfer proteins increased cholesterol esterification in all systems. The data demonstrate that large-sized, triglyceride-rich VLDL particles are preferred acceptors for transferred cholesteryl esters. It is suggested that enrichment of very low density lipoproteins with cholesteryl esters reflects the triglyceride content of the particles

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

    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.

  15. Effect of Anorganic Substance on Physical Properties of Poly (Butylene Succinate -co- Adipate) Irradiated by Electron Beam

    Poly(butylene succinate-co-adipate), PBSA were electron beam irradiated in the presence of inorganic materials. The samples gave high gel fraction by irradiation in the presence of 2% silicon dioxide and 2% carbon black. It was found that addition of carbon black (CB) was effective for improving the heat stability of the sample. This is because of three-dimensional carbon black- polymer networks. Irradiated PBSA sheets broke immediately at 110 oC with load 6.67 kgf/cm2, while irradiated the same sample mixed with 2% carbon black did not break at the same condition. Biodegradability of crosslinked PBSA by soil burial tests was accelerated by addition of carbon black. (author)

  16. Influence of end groups in hyperbranched polyesters used as modifiers in the characteristics of epoxy thermosets cured by adipic dihydrazide

    A. Serra

    2013-07-01

    Full Text Available Mixtures of diglycidylether of bisphenol A (DGEBA resin and different ratios of aliphatic-aromatic hyperbranched polyester (HBP were cured by a latent curing agent, adipic dihydrazide (AH. The HBPs prepared have hydroxyl groups or 10-undecenoyl or allyl groups as chain ends. The curing mixtures were investigated by differential scanning calorimetry (DSC to study the curing process and to evaluate the kinetic parameters of the different formulations. These studies suggest that HBPs decrease the curing rate of epoxy/AH in the case of vinyl terminated HPB, whereas OH terminated HBP accelerates the first stages and delays the lasts. The thermosets obtained showed an improvement in microhardness and impact strength without any reduction of the Tg and thermal parameters. Microparticle phase separation was observed with the undecenoyl HBP derivatives or when a 10% of allyl HBP derivative was in the formulation.

  17. Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign

    Petersen, Jens Højslev; Breindahl, T.

    1998-01-01

    , olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA...... could be determined by CC-MS without further clean-zip. A good consistency between results from the two different methods was obtained During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control...... Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil...

  18. Dissociative Ionization Mechanism and Appearance Energies in Adipic Acid Revealed by Imaging Photoelectron Photoion Coincidence, Selective Deuteration, and Calculations.

    Heringa, Maarten F; Slowik, Jay G; Prévôt, André S H; Baltensperger, Urs; Hemberger, Patrick; Bodi, Andras

    2016-05-26

    Adipic acid, a model compound for oxygenated organic aerosol, has been studied at the VUV beamline of the Swiss Light Source. Internal energy selected cations were prepared by threshold photoionization using vacuum ultraviolet synchrotron radiation and imaging photoelectron photoion coincidence spectroscopy (iPEPICO). The threshold photoelectron spectrum yields a vertical ionization energy (IE) of 10.5 eV, significantly above the calculated adiabatic IE of 8.6 eV. The cationic minimum is accessible after vertical ionization by H-transfer from one of the γ-carbons to a carbonyl oxygen and is sufficiently energetic to decay by water loss at the ionization onset. The slope of the breakdown curves, quantum chemical calculations, and selective deuteration of the carboxylic hydrogens establish the dissociative photoionization mechanism. After ionization, one γ-methylene hydrogen and the two carboxylic hydrogens are randomized prior to H2O loss. On the basis of the deuteration degree in the H2O + CO-loss product at higher energies, a direct water-loss channel without complete randomization also exists. The breakdown diagram and center of gravity of the H2O + CO-loss peak were modeled to obtain 0 K appearance energies of 10.77, 10.32, and 11.53 eV for H2O + CO loss, CH2COOH loss, and H2O + CH2COOH loss from adipic acid. These agree well with the CBS-QB3 calculated values of 10.68, 10.45, and 11.57 eV, respectively, which shows that threshold photoionization can yield energetics data as long as the dissociation is statistical, even when the parent ion cannot be observed. The results can be used as a starting point for a deeper understanding of the ionization and low-energy fragmentation of organic aerosol components. PMID:27100102

  19. A preliminary study on anti-radiation effects of two cinnamic paeonol ester compounds

    Objective: To study the anti-radiation effect of two cinnamic paeonol ester compounds. Method: The index like white blood cell count, platelet count,bone marrow nucleated cells count, DNA and other organ index on ICR mice were observed to investigate the anti-radiation effect of the two compounds in high, medial and low dosages. Results: Compared to the control group, the increase of DNA content in marrow,the number of splenic nodules, splenic index and thymus index have been observed in group of 4-methyl cinnamic acid paeonol ester and 4-fluoro cinnamic acid paeonol ester. Conclusion: 4-methyl cinnamic acid paeonol ester and 4-fluoro cinnamic acid paeonol ester both have the protection effect against radiation damage. (authors)

  20. Technical performance of vegetable oil methyl esters with a high iodine number

    Prankl, H.; Woergetter, M.; Rathbauer, J. [Federal Institute of Agricultural Engineering, Wieselburg (Austria)

    1999-07-01

    The Federal Institute of Agricultural Engineering in Austria has been gaining more experience about the technical performance of biodiesel with a high iodine number. Long-term bench tests evaluated rape seed oil methyl ester, sunflower oil methyl ester and camelina oil methyl ester with an iodine number of 107 to 150. The oil viscosity was observed and the engine parts were inspected after each run. To demonstrate the suitability of a methyl ester with a high iodine number, a fleet of nine vehicles and one stationary engine was tested for one to three engine oil drain intervals. Camelina oil methyl ester, with a content of 37% linolenic acid (C18:3), was used. No unusual deposits were observed after dismantling the engines. (author)

  1. Environmental effect of rapeseed oil ethyl ester

    Exhaust emission tests were conducted on rapeseed oil methyl ester (RME), rapeseed oil ethyl ester (REE) and fossil diesel fuel as well as on their mixtures. Results showed that when considering emissions of nitrogen oxides (NOx), carbon monoxide (CO) and smoke density, rapeseed oil ethyl ester had less negative effect on the environment in comparison with that of rapeseed oil methyl ester. When fuelled with rapeseed oil ethyl ester, the emissions of NOx showed an increase of 8.3% over those of fossil diesel fuel. When operated on 25-50% bio-ester mixed with fossil diesel fuel, NOx emissions marginally decreased. When fuelled with pure rapeseed oil ethyl ester, HC emissions decreased by 53%, CO emissions by 7.2% and smoke density 72.6% when compared with emissions when fossil diesel fuel was used. Carbon dioxide (CO2) emissions, which cause greenhouse effect, decreased by 782.87 g/kWh when rapeseed oil ethyl ester was used and by 782.26 g/kWh when rapeseed oil methyl ester was used instead of fossil diesel fuel. Rapeseed oil ethyl ester was more rapidly biodegradable in aqua environment when compared with rapeseed oil methyl ester and especially with fossil diesel fuel. During a standard 21 day period, 97.7% of rapeseed oil methyl ester, 98% of rapeseed oil ethyl ester and only 61.3% of fossil diesel fuel were biologically decomposed. (author)

  2. Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

    Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

    2016-01-01

    Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line. PMID:25912558

  3. Synthesis of substituted 2-cyanoarylboronic esters

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael; Kristensen, Jesper L

    2006-01-01

    The synthesis of substituted 2-cyanoarylboronic esters is described via lithiation/in situ trapping of the corresponding methoxy-, trifluoromethyl-, fluoro-, chloro-, and bromobenzonitriles. The crude arylboronic esters were obtained in high yields and purities and with good regioselectivities....

  4. Biodiesel With Optimized Fatty Ester Composition

    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...

  5. Electrochemistry of polyamidoamine dendrimers ester gel electrolytes

    CHEN Hong; MO Zunli

    2004-01-01

    This paper described the first example of polyamidoamine dendrimers ester (PAMAM) used as a gel electrolyte with a short-chain polyethylene glycol (MPEG-400) as a plasticizer. The polymer films are solid and sticky. Background cyclic voltammetry (CV) shows a potential window between +0.7 and -0.7 V vs. Ag/AgCl. The voltammetry of ferrocene and 7,7,8,8-tetracyanoquinodimethane (TCNQ) indicates that diffusion coefficients are in the range of 10-a-10-9 cm2/s.Ionic conductivities are approximately 10-6 S/cm. Similar films using dimethyl sulfoxide (DMSO) as a plasticizer instead of MPEG-400 have demonstrated ionic conductivities of 10-4 S/cra and reversible voltammetry. However, UV spectrophotometry shows that 70% of the DMSO is lost under vacuum, indicating the difficulty in quantifying the DMSO content when exposed to vacuum.

  6. Lutein and lutein esters in marigold flowers by high performance chromatography

    JIANG Xin-yu; CHEN Long-sheng; ZHOU Chun-shan

    2005-01-01

    Lutein and lutein esters in marigold flowers was quantitatively determined by high performance chromatography (HPLC) with ODS-C18 column. A mixture of CH3CN - CH3OH - CH3COOCH2CH3 with volume ratio of 55: 1: 44 was used as mobile phase at a flow rate of 1.0 mL/min and detection was carried out at 460 nm. The column temperature was about 20 ℃. The contents of lutein and lutein esters were determined by analytical curve of lutein since lutein and lutein esters have the same spectral characteristics. Determination results of hexane extracts and saponified samples of lutein show that the saponification transforms the esters into free lutein. The increase of the content of dipalmitate and palmitate stearate reveals that the reaction includes transesterifications.

  7. Synthesis of biocompatible poly(ε-caprolactone)-block-poly(propylene adipate) copolymers appropriate for drug nanoencapsulation in the form of core-shell nanoparticles

    Nanaki SG; Pantopoulos K; Bikiaris DN

    2011-01-01

    Stavroula G Nanaki1, Kostas Pantopoulos2, Dimitrios N Bikiaris11Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece; 2Lady Davis Institute for Medical Research and Department of Medicine, McGill University, Montreal, Quebec, CanadaAbstract: Poly(propylene adipate)-block-poly(ε-caprolactone) copolymers were synthesized using a combination of polycondensation and ring-opening polymerization of...

  8. Synthesis of biocompatible poly(ɛ-caprolactone)- block-poly(propylene adipate) copolymers appropriate for drug nanoencapsulation in the form of core-shell nanoparticles

    Bikiaris, Dimitrios; Nanaki,; Pantopoulos,

    2011-01-01

    Stavroula G Nanaki1, Kostas Pantopoulos2, Dimitrios N Bikiaris11Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Macedonia, Greece; 2Lady Davis Institute for Medical Research and Department of Medicine, McGill University, Montreal, Quebec, CanadaAbstract: Poly(propylene adipate)-block-poly(ε-caprolactone) copolymers were synthesized using a combination of polycondensation and ring-opening polymerization of...

  9. Enhancement of Mechanical and Thermal Properties of Oil Palm Empty Fruit Bunch Fiber Poly(butylene adipate-co-terephtalate) Biocomposites by Matrix Esterification Using Succinic Anhydride

    Samira Siyamak; Nor Azowa Ibrahim; Sanaz Abdolmohammadi; Wan Md Zin Bin Wan Yunus; Mohamad Zaki AB Rahman

    2012-01-01

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (EcoflexTM), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites’ performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence ...

  10. KARAKTERISTIK EMULSI SANTAN DAN MINYAK KEDELAI YANG DITAMBAH GUM ARAB DAN SUKROSA ESTER [Emulsion Characteristics of Coconut Milk and Soybean Oil Added with Gum Arabic and Sucrose Ester

    Laksmi Hartayanie

    2015-07-01

    Full Text Available High saturated fatty acid content in coconut milk can be reduced by adding unsaturated fat. Pretreatment such as pasteurisation, homogenization or stabilizer and emulsifier addition are essential to prevent emulsion deterioration that could happen in few hours. This study aimed to determine the most appropriate combination of gum arabic and sucrose ester to produce good emulsion stability based on its physical and chemical characteristics. Furthermore this study also aimed to determine correlation between creaming index and other characteristics of coconut milk emulsion. Emulsion stability of mixed coconut milk in sterile glass bottles was observed for 7 days under 23-24°C. Stabilizer and emulsifier added were gum arabic and sucrose ester in five combinations, i.e. 6% gum arabic, 0.3% sucrose ester, 6% gum arabic + 0.3% sucrose ester, 3% gum arabic + 0.15% sucrose ester and 4.5% gum arabic + 0.225% sucrose ester. The physical characteristics evaluated were creaming index, total color change, viscosity and droplet distribution, while the chemical characteristics observed included pH, TBA value, and protein content. Data were analyzed by One Way Anova at 95% significant level to determine the differences among treatments. Bivariate Pearson Correlation was used in order to determine the interaction among sample characteristics. The data showed that, gum arabic and sucrose ester can maintain the emulsion stability. A combination of 4.5% gum arabic and 0.225% sucrose ester provided the best physicochemical characteristics with the lowest creaming index and decreased viscosit, and uniform droplet distribution.

  11. Characteristics of polyglycerol ester and its different fractions.

    Curschellas, Corina; Nagy, Kornél; Windhab, Erich; Limbach, Hans Jörg

    2013-03-01

    Polyglycerol esters obtained from edible oils are commonly used surfactants in the food industry. Despite their widespread application, the composition and properties of these surfactants are still not well characterized. This study reveals the presence of so far unknown tetra-, penta-antennary constituents in polyglycerol esters, which exhibit very strong sodium affinity. The implications of these new insights on surfactant activity were investigated. Liquid-liquid extraction was used to fractionate a polyglycerol ester ingredient in order to link physicochemical behavior to the polarity of the fractions. The most polar fraction showed faster adsorption kinetics and higher elastic moduli than the full mixture, whereas the least polar fraction showed slower adsorption kinetics and lower elastic moduli as compared to the complex mixture. The addition of Na(+) was shown to accelerate the agglomeration of surfactant self-assemblies in bulk solutions and also to increase the elastic modulus at the air-water interface. These observations suggest that the composition of natural polyglycerol esters is more diverse than so far assumed and the overall behavior of these mixtures is determined not only by the amphyphilic interactions between mono- and penta-antennary forms, but also by the endogenous salt content of the ingredient. PMID:23207050

  12. Production and characterization of novel starch and poly(butylene adipate-co-terephthalate)-based materials and their applications

    Stagner, Jacqueline Ann

    This work focuses on the production and characterization of blends of maleated thermoplastic starch (MTPS) and poly(butylenes adipate-co-terephthalate) and their application for use as thermoformed objects, films, and foams. First, by the production and characterization of maleated thermoplastic starch (MTPS) synthesized by reactive extrusion in a twin-screw extruder, a better understanding of MTPS was gained. This reactive thermoplastic starch was prepared with glycerol as the plasticizer, maleic anhydride (MA), and free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox 101). Dynamic light scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), soxhlet extraction in acetone, and environmental scanning electron microscopy (ESEM) were performed to determine the effect of maleation, extrusion temperature, initiator concentration, and maleic anhydride concentration on the resulting MTPS. Next, maleated thermoplastic starch (MTPS) and thermoplastic starch (TPS) were reactively blended in a twin-screw extruder with a biodegradable polyester, poly(butylene adipate-co-terephthalate) (PBAT). The blends were extruded to produce thermoformable sheets. The mechanical properties of the sheets were characterized by tensile and puncture tests. Proof of grafting was determined by soxhlet extraction in dichloromethane and FTIR analysis. Observations of the thermal properties were made using DSC, while the surface of the sheets was imaged using ESEM. Blends of MTPS and PBAT were also extruded to produce films. Mechanical testing (tensile and puncture tests) and barrier performance testing (carbon dioxide, oxygen, and water vapor permeability) were performed on the films. Transmission electron microscopy (TEM) was used to image the blends and to view the dispersion of the various phases. Finally, blends of MTPS and PBAT were extruded with an endothermic chemical blowing agent to produce foams. The foams were

  13. Mechanism of formation of 3-chloropropan-1,2-diol (3-MCPD) esters under conditions of the vegetable oil refining.

    Šmidrkal, Jan; Tesařová, Markéta; Hrádková, Iveta; Berčíková, Markéta; Adamčíková, Aneta; Filip, Vladimír

    2016-11-15

    3-MCPD esters are contaminants that can form during refining of vegetable oils in the deodorization step. It was experimentally shown that their content in the vegetable oil depends on the acid value of the vegetable oil and the chloride content. 3-MCPD esters form approximately 2-5 times faster from diacylglycerols than from monoacylglycerols. It has been proved that the higher fatty acids content in the oil caused higher 3-MCPD esters content in the deodorization step. Neutralization of free fatty acids in the vegetable oil before the deodorization step by alkaline carbonates or hydrogen carbonates can completely suppress the formation of 3-MCPD esters. Potassium salts are more effective than sodium salts. PMID:27283615

  14. Enantiospecific Alkynylation of Alkylboronic Esters

    Wang, Yahui; Noble, Adam; Myers, Eddie L.; Aggarwal, Varinder K.

    2016-01-01

    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 the use of α-lithio vinyl bromide or vinyl carbamate, species whose application to Zweifel-type reactions has not previously been explored. The resulting functionalized 1,1-disubstituted alkenes undergo facile base-mediated elimination to generate the terminal alkyne products in hig...

  15. Methods of making alkyl esters

    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.

  16. Sesquiterpene Esters from Salvia roborowskii

    Ya LI; Ning LOU; Yan Qi WU; Xian Feng LIN; Yu LI

    2003-01-01

    Two new sesquiterpene esters, 3β, 6β, 8α-triacetyl-4β, 5α-epoxy -1- oxogermacr-10(14)-ene (1) and 3β, 6β, 8α-triacetyl-4β, 5α-epoxygermacr-1(10)-ene (2) were isolated from the whole plant of Salvia roborowskii Maxim. Their structures were elucidated by means of spectral data (2DNMR and HRMS).

  17. Effect of organo-modified montmorillonite on poly(butylene succinate/poly(butylene adipate-co-terephthalate nanocomposites

    2010-07-01

    Full Text Available The composite material based on poly(butylene succinate (PBS, poly(butylene adipate-co-terephthalate (PBAT and organo-modified montmorillonite (OMMT were prepared by melt blending technique and characterized. Sodium montmorillonite (Na-MMT was successfully modified by octadecylammonium (ODA and dimethyldioctadecylammonium (DDOA salts to become OMMT through cation exchange technique which is shown by the increase of basal spacing of clay by XRD. The addition of the OMMT to the PBS/PBAT blends produced nanocomposites which is proved by XRD and TEM. Tensile tests showed increase in tensile strength and modulus which is attributed to the existence of strong interactions between PBS/PBAT and clay, particularly with OMMT. Highest tensile strength of nanocomposite was observed at 1 wt% of OMMT incorporated. TGA study showed that the thermal stability of the blend increased after the addition of clays. SEM micrographs of the fracture surfaces show that the morphology of the blend becomes homogeneous and smoother with presence of OMMT.

  18. Poly(lactide-g-poly(butylene succinate-co-adipate with High Crystallization Capacity and Migration Resistance

    Xi Yang

    2016-04-01

    Full Text Available Plasticized polylactide (PLA with increased crystallization ability and prolonged life-span in practical applications due to the minimal plasticizer migration was prepared. Branched plasticized PLA was successfully obtained by coupling poly(butylene succinate-co-adipate (PBSA to crotonic acid (CA functionalized PLA. The plasticization behavior of PBSA coupled PLA (PLA-CA-PBSA and its counterpart PBSA blended PLA (PLA/PBSA were fully elucidated. For both PLA-CA-PBSA and PLA/PBSA, a decrease of Tg to around room temperature and an increase in the elongation at break of PLA from 14% to 165% and 460%, respectively, were determined. The crystallinity was increased from 2.1% to 8.4% for PLA/PBSA and even more, to 10.6%, for PLA-CA-PBSA. Due to the inherent poor miscibility between the PBSA and PLA, phase separation occurred in the blend, while PLA-CA-PBSA showed no phase separation which, together with the higher crystallinity, led to better oxygen barrier properties compared to neat PLA and PLA/PBSA. A higher resistance to migration during hydrolytic degradation for the PLA-CA-PBSA compared to the PLA/PBSA indicated that the plasticization effect of PBSA in the coupled material would be retained for a longer time period.

  19. Synthesis and properties of chemiluminescent acridinium ester labels with fluorous tags.

    Natrajan, Anand; Wen, David; Sharpe, David

    2014-06-21

    Acridinium dimethylphenyl esters are highly sensitive chemiluminescent labels that are used in clinical diagnostics. Light emission from these labels is triggered with alkaline peroxide in the presence of the cationic surfactant cetyltrimethylammonium chloride (CTAC). CTAC compresses emission times of these labels to fluorous tags of varying fluorine content and their chemiluminescence in the presence of cationic micelles of CTAC, anionic micelles of sodium perfluorooctanoate (SPFO) as well as mixed micelles of CTAC and SPFO. These studies indicate that in the presence of the mixed micelle system of CTAC and SPFO and at low mole fractions of SPFO, polarity of the mixed micelle interface is lower than that of CTAC leading to a greater enhancement of chemiluminescence for both fluorinated acridinium esters as well as a structurally analogous but non-fluorinated acridinium ester. Chemiluminescence stability of the fluorinated acridinium esters was either comparable to or better than the stability of the non-fluorinated acridinium ester. Non-specific binding to paramagnetic microparticles was higher for fluorinated acridinium esters requiring a surfactant wash to reduce their non-specific binding to the same extent as that observed for the non-fluorinated acridinium ester. PMID:24788381

  20. Identification and dosage by HRGC of minor alcohol and esters in Brazilian sugar-cane spirit

    Boscolo, Mauricio; Bezerra, Cicero W.B.; Cardoso, Daniel R.; Lima Neto, Benedito S.; Franco, Douglas W. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica

    2000-02-01

    The presence of 51 volatile compounds, among alcohols and esters in Brazilian sugar-cane spirit (cachaca), were investigated by high-resolution gas chromatography (HRGC). The following alcohols and esters were identified and quantified: methanol, 1,4-butanodiol, 2-phenylethyl alcohol, amyl alcohol, cetyl alcohol, cynamic alcohol, n-decanol, geraniol, isoamyl alcohol, isobutanol, menthol, n-butanol, n-dodecanol, n-propanol, n-tetradecanol, amyl propionate, ethyl acetate, ethyl benzoate, ethyl heptanoate, isoamyl valerate, methyl propionate, propyl butyrate. The average higher alcohols content (262 mg/100 mL in anhydrous alcohol a.a) and total esters content (24 mg/100 mL a.a) in cachacas, are smaller than in other spirits. The average methanol content in cachacas (6 mg/100 mL a.a) is the same as in rum, but smaller than in wine spirit. No qualitative differences of chemical profile among cachacas have been observed. (author)

  1. Identification and dosage by HRGC of minor alcohol and esters in Brazilian sugar-cane spirit

    The presence of 51 volatile compounds, among alcohols and esters in Brazilian sugar-cane spirit (cachaca), were investigated by high-resolution gas chromatography (HRGC). The following alcohols and esters were identified and quantified: methanol, 1,4-butanodiol, 2-phenylethyl alcohol, amyl alcohol, cetyl alcohol, cynamic alcohol, n-decanol, geraniol, isoamyl alcohol, isobutanol, menthol, n-butanol, n-dodecanol, n-propanol, n-tetradecanol, amyl propionate, ethyl acetate, ethyl benzoate, ethyl heptanoate, isoamyl valerate, methyl propionate, propyl butyrate. The average higher alcohols content (262 mg/100 mL in anhydrous alcohol a.a) and total esters content (24 mg/100 mL a.a) in cachacas, are smaller than in other spirits. The average methanol content in cachacas (6 mg/100 mL a.a) is the same as in rum, but smaller than in wine spirit. No qualitative differences of chemical profile among cachacas have been observed. (author)

  2. Ester Tuiksoo. Proua Suhkru kibedad päevad / Ester Tuiksoo ; interv. Piret Tali

    Tuiksoo, Ester, 1965-

    2005-01-01

    Põllumajandusminister Ester Tuiksoo, kellel peagi täitub ministri ametis aasta Euroopa Liidu suhkrutrahvist, maaettevõtlusest, põllumajandusest, Euroopa Liidu toetustest, ministri elu- ja teenistuskäigust. Lisa: Ester Tuiksoo

  3. Identification of rapeseed oil fatty acid esters in transesterification reactions by gas chromatography - mass spectrometry method

    Rapeseed oil transesterification with different alcohols - methyl, ethyl, n-propyl and isopropyl alcohol - has been carried out. Yields of fatty acid alkyl esters obtained from rapeseed oil were determined using the internal standard method. Results of interpretation of the obtained ester mass spectra are reported. The specimen of Latvian rape oil contains: 57.6% of oleic acid, 18.2% of linoleic acid, 8.2% linolenic acid, 3.3% palmitic acid, 2% of stearic acid and less than 1% of arachidic acid. Values of Kovats retention indices of the rapeseed oil fatty acid esters on the capillary columns DB-5 MS and DB-17 MS have been compared. More selective separation of fatty acid alkyl esters has been achieved on the stationary phase with higher content of phenyl groups (DB-17 MS). (authors)

  4. Carboxylic Acid Esters as Substrates of Cholinesterases

    Brestkin, A. P.; Rozengart, E. V.; Abduvakhabov, A. A.; Sadykov, A. A.

    1983-10-01

    Data on the kinetics of the hydrolysis of various carboxylic acid esters by two main types of cholinesterases — acetylcholinesterase from human erythrocytes and butyrylcholinesterase from horse blood serum — are surveyed. It is shown that the rate of enzyme hydrolysis depends significantly on the structure of the acyl part of the ester molecule, the nature of the ester heteroatom, the structure of the alcohol component, and particularly the structure of the onium group. Esters based on natural products are of special interest as specific substrates of these enzymes. The role of the productive and non-productive sorption of the substrates in enzyme catalysis is demonstrated. The bibliography includes 81 references.

  5. Polymeric chains, hydrogen bonds and magnetism in Nd(III) adipates

    An AC susceptibility study of [Nd2(O2C(CH2)4CO2)3(H2O)2] (1) obtained from a solution at ambient conditions was performed in the range 14-320K. An ordering transition, TC=280(2)K, not related to a structural phase transition, a ferromagnetic like Curie-Weiss behavior above TC, an antiferromagnetic like dependence of χ'-1 at the lowest temperatures and a non-linear thermal dependence of χ'-1 in the in-between region have been observed. Samples prepared by hydration of 1 during different periods showed enhancement of the observed features. Links between water content, crystal structure and magnetic response are discussed

  6. γ-Glutamyl semialdehyde and 2-amino-adipic semialdehyde: biomarkers of oxidative damage to proteins

    Daneshvar, B.; Frandsen, H.; Autrup, Herman

    1997-01-01

    Reactive oxygen species are formed in the body by several natural processes and by induced oxidative stress. The reactive oxygen species may react with the various biomolecules of the body, including proteins. In order to assess the impact of oxidative damage to proteins, we have tried to identify...... oxidized amino acids in blood proteins which might serve as biomarkers of oxidative damage. When oxidative damage is induced into bovine serum albumin by metal-catalysed oxidation systems, the aldehyde groups formed can be derivatized by fluoresceinamine (FINH2). Following acid hydrolysis of FINH2...... or Pro, while AAS is an oxidation product of Lys. When oxidative stress was induced in rats by treatments with t-butyl hydroperoxide or acrolein, rat plasma protein levels of GGS and AAS were found to be significantly higher compared with control rats. The AAS-content in serum albumin or in total...

  7. Synthesis of insecticidal sucrose esters

    Song Zi-juan; Li Shu-jun; Chen Xi; Liu Li-mei; Song Zhan-qian

    2006-01-01

    Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg·mL-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg·mL-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.

  8. Mesoporous core–shell Fenton nanocatalyst: a mild, operationally simple approach to the synthesis of adipic acid.

    Patra, Astam K; Dutta, Arghya; Bhaumik, Asim

    2013-09-01

    Mesoporous nanoparticles composed of γ-Al2O3 cores and α-Fe2O3 shells were synthesized in aqueous medium. The surface charge of γ-Al2O3 helps to form the core–shell nanocrystals. The core–shell structure and formation mechanism have been investigated by wide-angle XRD, energy-dispersive X-ray spectroscopy, and elemental mapping by ultrahigh-resolution (UHR) TEM and X-ray photoelectron spectroscopy. The N2 adsorption–desorption isotherm of this core–shell materials, which is of type IV, is characteristic of a mesoporous material having a BET surface area of 385 m2 g(−1) and an average pore size of about 3.2 nm. The SEM images revealed that the mesoporosity in this core–shell material is due to self-aggregation of tiny spherical nanocrystals with sizes of about 15–20 nm. Diffuse-reflectance UV/Vis spectra, elemental mapping by UHRTEM, and wide-angle XRD patterns indicate that the materials are composed of aluminum oxide cores and iron oxide shells. These Al2O3@Fe2O3 core–shell nanoparticles act as a heterogeneous Fenton nanocatalyst in the presence of hydrogen peroxide, and show high catalytic efficiency for the one-pot conversion of cyclohexanone to adipic acid in water. The heterogeneous nature of the catalyst was confirmed by a hot filtration test and analysis of the reaction mixture by atomic absorption spectroscopy. The kinetics of the reaction was monitored by gas chromatography and 1H NMR spectroscopy. The new core–shell catalyst remained in a separate solid phase, which could easily be removed from the reaction mixture by simple filtration and the catalyst reused efficiently. PMID:24167824

  9. Production and Treatment of Three Waste in Adipic Acid Prodution%己二酸生产中“三废”的产生与处理

    董菲菲; 许小军

    2015-01-01

    From green prodution ,the causes of three waste prodution in mainstream adipic acid production at home are summarized ,the treatment method for waste gas ,waste liquid,waste solid are introduced .%从绿色生产的角度总结了目前国内主流的己二酸生产工艺中工业三废产生的原因,从废气、废液、废固三方面介绍了其相对应的处理方法。

  10. THERMAL PROPERTY, MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF POLY(3-HYDROXYBUTYRATE-co 3-YDROXYHEXANOATE) AND POLY(BUTYLENE SUCCINATE-ADIPATE) (PHBHHX/PBSA) BLENDS

    2005-01-01

    Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.

  11. Effekte der L-Carnitinsupplementierung auf das metabolische Profil adipöser und insulinresistenter Ponys im Verlaufe einer mehrwöchigen Körpergewichtsreduktion

    Schmengler, Uta

    2013-01-01

    Zusammenfassung: Effekte der L-Carnitinsupplementierung auf das metabolische Profil adipöser und insulinre- sistenter Ponys im Verlaufe einer mehrwöchigen Körpergewichtsreduktion Author: Uta Schmengler Institut für Tierernährung, Ernährungsschäden und Diätetik, Veterinärmedizinische Fakultät, Universität Leipzig Eingereicht im September 2012 76 S., 16 Abb., 23 Tab., 169 Lit., Anhang Einleitung: Das ”Equine Metabolische Syndrom” ist gekennzeichnet durch eine region...

  12. Experimental improvement of preparation for adipic acid through oxidation of potassium permanganate%高锰酸钾氧化制备己二酸的实验改进

    徐翔宇

    2011-01-01

    通过改变高锰酸钾氧化环己醇制备己二酸的方法,使制备己二酸的实验变得简便、过程简单、反应时间缩短、产率提高、实验效果理想.%Through changing the method of the preparation for adipic acid of the potassium permanganate oxidizing cyclohexanol, the experiment of preparation for adipic acid becomes more simple and convenient. The whole process is simple, the reaction time is shortened, the yield is increased and the experimental results are very ideal.

  13. Glutathione isopropyl ester reduces UVB-induced skin damage in hairless mice

    The protective effect of administration of glutathione (GSH) isopropyl ester on photodamage, such as lipid peroxidation, inflammation and tumorigenesis induced by UV exposure (290-400 nm, max. 312 nm), was investigated using hairless mice. Pretreatment with 20 mg/kg GSH isopropyl ester prevented the increases of thiobarbituric acid-reactive substance (TBARS) formation in skin and serum sialic acid, indices of lipid peroxidation and inflammatory reaction, respectively, which were caused by a single dose (15kJ/m2) of UV irradiation. The level of epidermal GSH in skins of the GSH ester-treated mice was maintained within normal limits. When mice were exposed to UV at a dose of 2 kJ/m2, three times weekly, skin tumors developed in all of them after 25 weeks. The formation of skin tumors was significantly inhibited by administration of 10 mg/kg GSH ester prior to each UV irradiation for 25 weeks. Moreover, the increases of cutaneous TBARS and serum sialic acid in the tumor-bearing mice were also prevented by continuous pretreatment with GSH ester. Even after 24 weeks, the epidermal GSH content of the pretreated mice was mostly retained compared to nonirradiated mice. However, administration of GSH prior to acute or chronic UV irradiation had no effect on the UV-induced damage. The present results suggest that the protection from photodamage afforded by pretreatment with GSH ester is due to maintenance of a normal GSH level. (Author)

  14. Enzymatic synthesis and application of fatty acid ascorbyl esters

    Stojanović Marija M.

    2013-01-01

    Full Text Available Fatty acid ascorbyl esters are liposoluble substances that possess good antioxidative properties. These compounds could be synthesized by using various acyl donors for acylation of vitamin C in reaction catalyzed by chemical means or lipases. Enzymatic process is preferred since it is regioselective, performed under mild reaction conditions, with the obtained product being environmentally friendly. Polar organic solvents, ionic liquids, and supercritical fluids has been successfully used as a reaction medium, since commonly used solvents with high Log P values are inapplicable due to ascorbic acid high polarity. Acylation of vitamin C using fatty acids, their methyl-, ethyl-, and vinyl esters, as well as triglycerides has been performed, whereas application of the activated acyl donors enabled higher molar conversions. In each case, majority of authors reported that using excessive amount of the acyl donor had positive effect on yield of product. Furthermore, several strategies have been employed for shifting the equilibrium towards the product by water content control. These include adjusting the initial water activity by pre-equilibration of reaction mixture, enzyme preparation with water vapor of saturated salt solutions, and the removal of formed water by the addition of molecular sieves or salt hydrate pairs. The aim of this article is to provide a brief overview of the procedures described so far for the lipase-catalyzed synthesis of fatty acid ascorbyl esters with emphasis on the potential application in food, cosmetics, and pharmaceutics. Furthermore, it has been pointed out that the main obstacles for process commercialization are long reaction times, lack of adequate purification methods, and high costs of lipases. Thus, future challenges in this area are testing new catalysts, developing continuous processes for esters production, finding cheaper acyl donors and reaction mediums, as well as identifying standard procedures for

  15. Polymer blends of polylactic acid (PLA) and polybutylene succinate-adipate

    Ma, Wenguang

    A series of blends consisting of polylactic acid (PLA) and aliphatic succinate polyester (BionolleRTM #3000) had been prepared and investigated. The results of mechanical property investigations showed that using 20 wt% Bionolle#3000 can significantly increase the toughness of PLA. BionolleRTM #3000 also reduces the physical aging rate of PLA so blends remain tough longer. Conversely, the stiffness of BionolleRTM #3000 can be significantly increased by blending in PLA. DMA and DSC results show that PLA/BionolleRTM 3000 blends are not thermodynamically miscible, but are compatible blends. Studies have also been performed to determine the amount and rate of aerobic biodegradation of PLA/aliphatic succinate polyester blends in biologically active composting, enzymatic, and soil environments. The changes in molecular weight, molecular structure and thermal properties in the composting environment were also studied by GPC, NMR and DSC analyses. The research results showed BionolleRTM #3000 had a high degradation rate, while PLA had a low degradation rate. PLA/BionolleRTM #3000 blends had moderate degradation rates that increased with BionolleRTM #3000 content. The melt flow behavior of PLA/BionolleRTM #3000 blends has been studied by capillary rheometry. The relationship of the blends' viscosity with their composition, shear stress, shear rate, and temperature has been investigated. Power law index and activation energy of PLA, BionolleRTM #3000 and their blends have been calculated. The experimental and theoretical data can let us understand the processability of PLA/BionolleRTM #3000 blends. A scanning electron microscope (SEM) was used to investigate the morphological structure of the PLA/BionolleRTM #3000 blends. Micrographs of the samples made from different methods (blown film, extrudate and compression molding sheet) were taken; their differences in morphology were compared. For comparison, the micrographs of blend PLA/BionolleRTM #6000 was also studied. The

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

    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...

  17. Cold Flow Properties of Fatty Esters

    Andrea Kleinová

    2007-09-01

    Full Text Available The article is devoted to the study of cold fl ow properties of neat esters of branched chain alcohols with fatty acids and blends of these esters with fossil diesel fuel. According to the determined CFPP values, the influence of alcohol branching on the fuel filterability is negligible and was detected only in the case of 2-ethyl hexanol. Fossil fuel blending with fatty esters up to 10 % vol. does not substantially change the cold flow properties of fossil fuel. DSC cooling scan parameters should be employed to predict CFPP of blended diesel fuel.

  18. Space-Qualifiable Cyanate Ester Elastomer Project

    National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG) proposes to design and develop a space-qualifiable cyanate ester elastomer for application in self-deployable space...

  19. Space-Qualifiable Cyanate Ester Elastomer Project

    National Aeronautics and Space Administration — In Phase 1, CRG demonstrated the feasibility of a novel approach to prepare cyanate ester based elastomers. This approach polymerizes in-situ siloxane within a...

  20. Rapid Output Growth of Special Acrylic Esters

    Wang Lianzhi

    2007-01-01

    @@ Acrylic esters are usually classified into general-purpose varieties and special varieties. The production and application of general-purpose varieties is already quite matured in the world and their output growth tends to be flat. Owing to the development of coatings, electronics, automobiles,textiles, printing and construction sectors, especially the application of radiation curing technology in various sectors, special acrylic esters have developed rapidly.

  1. Synthesis of a new energetic nitrate ester

    Chavez, David E [Los Alamos National Laboratory

    2008-01-01

    Nitrate esters have been known as useful energetic materials since the discovery of nitroglycerin by Ascanio Sobrero in 1846. The development of methods to increase the safety and utility of nitroglycerin by Alfred Nobel led to the revolutionary improvement in the utility of nitroglycerin in explosive applications in the form of dynamite. Since then, many nitrate esters have been prepared and incorporated into military applications such as double-based propellants, detonators and as energetic plasticizers. Nitrate esters have also been shown to have vasodilatory effects in humans and thus have been studied and used for treatments of ailments such as angina. The mechanism of the biological response towards nitrate esters has been elucidated recently. Interestingly, many of the nitrate esters used for military purposes are liquids (ethylene glycol dinitrate, propylene glycol dinitrate, etc). Pentaerythritol tetranitrate (PETN) is one of the only solid nitrate esters, besides nitrocellulose, that is used in any application. Unfortunately, PETN melting point is above 100 {sup o}C, and thus must be pressed as a solid for detonator applications. A more practical material would be a melt-castable explosive, for potential simplification of manufacturing processes. Herein we describe the synthesis of a new energetic nitrate ester (1) that is a solid at ambient temperatures, has a melting point of 85-86 {sup o}C and has the highest density of any known nitrate ester composed only of carbon, hydrogen, nitrogen and oxygen. We also describe the chemical, thermal and sensitivity properties of 1 as well as some preliminary explosive performance data.

  2. Allied, MGC link on cyanate esters

    In the latest of a line of joint ventures in its plastics business, Allied Signal has reached agreement with Mitsubishi Gas Chemical (MGC) to jointly develop thermoset cyanate ester resins and blends. The deal will involve further development of Allied Signal's Primaset phenol-formaldehyde cyanate ester resins, a new entrant in the thermoset arena. Although the Primaset resins were discovered in the 1960s, this would be the first time they are available commercially. The deal will marry Primaset technology with MGC's Skylex bisphenol A cyanate ester resins, says Fred DiAntonis, director/advanced materials at Allied Signal. The two firms are looking at marketing blends of the two materials. The potential market for these resins, used commercially by the electronics industry in printed circuit boards and by the aerospace industry in composites, is significant, says Robert P. Viarengo, Allied Signal president/performance materials. By aligning ourselves with MGC, the world leader in cyanate ester resin, we anticipate moving forward aggressively. The main competitor is Ciba, which acquired bisphenol A cyanate ester resins with its purchase of Rhone-Poulenc's high temperature resins business. DiAntonis estimates the market for cyanate ester resins could be worth $150 million by the end of the decade, although development costs have been in the tens of millions of dollars range

  3. Use of calcium oxide in palm oil methyl ester production

    Kulchanat Prasertsit

    2014-04-01

    Full Text Available Introducing an untreated calcium oxide (CaO as a solid heterogeneous catalyst for biodiesel production from palm oil by transesterification was studied in this work. The four studied parameters were methanol to oil molar ratio, CaO catalyst concentration, reaction time, and water content. The results for palm oil show that when the water content is higher than 3%wt and the amount of CaO greater than 7%wt soap formation from saponification occurs. A higher methanol to oil molar ratio requires a higher amount of CaO catalyst to provide the higher product purity. The appropriate methanol to CaO catalyst ratio is about 1.56. Commercial grade CaO gives almost the same results as AR grade CaO. In addition, reusing commercial grade CaO for about 5 to 10 repetitions without catalyst regeneration drops the percentage of methyl ester purity approximately 5 to 10%, respectively.

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

    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

  5. Toxicokinetics, recovery, and metabolism of triclopyr butotyl (ACTP) ester in goats.

    Sar, Tapas K; Bagchi, Biplab; Das, Shyamal K; Mandal, Tapan K; Chakraborty, Animesh K; Bhattacharyya, Anjan; Choudhury, Ashim

    2002-07-17

    Toxicokinetic behavior, recovery, and metabolism studies of ACTP ester and its effect on cytochrome P(450) content of liver microsomal pellet were carried out in black Bengal goat after a single intravenous administration of 11.88 mg kg(-1) and consecutive oral administration of 79.22 mg kg(-1) for 7 days. ACTP ester achieved a maximum blood concentration of 42.64 +/- 4.26 microg mL(-1) at 0.08 h after intravenous administration followed by a sharp decline until 0.5 h, and the minimum blood concentration was recorded at 36 h (1.93 +/- 0.14 microg mL(-1)) postdosing. The kinetic behavior of ACTP ester followed a "two-compartment open model". Comparatively shorter alpha (0.81 +/- 0.02 h(-1)) and greater t1/2 (alpha) (0.86 +/- 0.03 h) indicated a slower rate of distribution of ACTP ester in goat. The t1/2(beta)()) (14.83 +/- 1.49 h) and V(d(area)) (0.91 +/- 0.19 L kg(-1)) suggested a longer elimination phase with general distribution in all compartments of the body. The higher T/B and K12/K21 values associated with a lower f(c) value suggested longer persistence in the tissue compartment at higher concentration. The higher Cl(R) compared to Cl(H) indicated the major amount was eliminated by the kidney. Maximum concentration of ACTP ester including its metabolites, triclopyr acid and trichloropyridinol, was excreted through urine at 48 h. The recovery of ACTP ester including metabolites after repeated nontoxic oral dose administration was 70.09%, of which recovery from feces was 4.45%, suggesting the major portion of administered ACTP ester was absorbed through the gastrointestinal tract of the goat. All of the tissues contained ACTP ester and its metabolites. ACTP ester did not alter the cytochrome P(450) content of the liver tissue following repeated nontoxic oral dose administration for 7 days. PMID:12105946

  6. Batch Production of Trimetylolpropane Ester from Palm Oil as Lubricant Base Stock

    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.

  7. Investigation of the morphology and surface properties of crosslinked poly(urethane-ester-siloxanes

    Jovanović Slobodan

    2012-01-01

    Full Text Available Two series of crosslinked poly(urethane-ester-siloxanes were synthesized from α,ω-dihydroxy-(ethylene oxide-poly(dimethylsiloxane-ethylene oxide (EO-PDMS-EO, 4,4’-methylenediphenyl diisocyanate and Boltorn® hyperbranched polyesters of the second and third pseudo generation, by a two-step polymerization in solution. The effect of the EO-PDMS-EO content and functionality of the applied crosslinking agent on the morphology and surface properties of the prepared poly(urethane-ester-siloxanes was investigated by FTIR spectroscopy, small-angle X-ray scattering (SAXS, atomic force microscopy (AFM, scanning electron microscopy (SEM and water absorption measurement. Different techniques (FTIR peak deconvolution, SAXS and AFM revealed that decrease of the crosslinking agent functionality and EO-PDMS-EO content promotes microphase separation in the synthesized poly(urethane-ester-siloxanes. SEM analysis and water absorption experiments showed that due to the hydrophobic character of EO-PDMS-EO and its ability to migrate to the surface of poly(urethane-ester-siloxanes, samples synthesized with higher EO-PDMS-EO content and crosslinking agent of lower functionality have more hydrophobic surface and better waterproof performances. The obtained results indicate that the synthesis of poly(urethane-ester-siloxanes based on EO-PDMS-EO and Boltorn® hyperbranched polyesters leads to the creation of networks with interesting morphological and surface properties, which can be easily tailored by changing the content of EO-PDMS-EO segment or functionality of hyperbranched polyester.

  8. Detection of testosterone esters in blood.

    Forsdahl, Guro; Erceg, Damir; Geisendorfer, Thomas; Turkalj, Mirjana; Plavec, Davor; Thevis, Mario; Tretzel, Laura; Gmeiner, Günter

    2015-01-01

    Injections of synthetic esters of testosterone are among the most common forms of testosterone application. In doping control, the detection of an intact ester of testosterone in blood gives unequivocal proof of the administration of exogenous testosterone. The aim of the current project was to investigate the detection window for injected testosterone esters as a mixed substance preparation and as a single substance preparation in serum and plasma. Furthermore, the suitability of different types of blood collection devices was evaluated. Collection tubes with stabilizing additives, as well as non-stabilized serum separation tubes, were tested. A clinical study with six participants was carried out, comprising a single intramuscular injection of either 1000 mg testosterone undecanoate (Nebido(®)) or a mixture of 30 mg testosterone propionate, 60 mg testosterone phenylpropionate, 60 mg testosterone isocaproate, and 100 mg testosterone decanoate (Sustanon(®)). Blood was collected throughout a testing period of 60 days. The applied analytical method for blood analysis included liquid-liquid extraction and preparation of oxime derivatives, prior to TLX-sample clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) detection. All investigated testosterone esters could be detected in post-administration blood samples. The detection time depended on the type of ester administered. Furthermore, results from the study show that measured blood concentrations of especially short-chained testosterone esters are influenced by the type of blood collection device applied. The testosterone ester detection window, however, was comparable. PMID:26695486

  9. Recovery of sterols as fatty acid steryl esters from waste material after purification of tocopherols.

    Nagao, Toshihiro; Hirota, Yoshinori; Watanabe, Yomi; Kobayashi, Takashi; Kishimoto, Noriaki; Fujita, Tokio; Kitano, Motohiro; Shimada, Yuji

    2004-08-01

    Tocopherols are purified industrially from soybean oil deodorizer distillate by a process comprising distillation and ethanol fractionation. The waste material after ethanol fractionation (TC waste) contains 75% sterols, but a purification process has not yet been developed. We thus attempted to purify sterols by a process including a lipase-catalyzed reaction. Candida rugosa lipase efficiently esterified sterols in TC waste with oleic acid (OA). After studying several factors affecting esterification, the reaction conditions were determined as follows: ratio of TC waste/OA, 1:2 (wt/wt); water content, 30%; amount of lipase, 120 U/g-reaction mixture; temperature, 40 degrees C. Under these conditions, the degree of esterification reached 82.7% after 24 h. FA steryl esters (steryl esters) in the oil layer were purified successfully by short-path distillation (purity, 94.9%; recovery, 73.1%). When sterols in TC waste were esterified with FFA originating from olive, soybean, rapeseed, safflower, sunflower, and linseed oils, the FA compositions of the steryl esters differed somewhat from those of the original oils: The content of saturated FA was lower and that of unsaturated FA was higher. The m.p. of the steryl esters synthesized (21.7-36.5 degrees C) were remarkably low compared with those of the steryl esters purified from high-b.p. soybean oil deodorizer distillate substances (56.5 degrees C; JAOCS 80, 341-346, 2003). The low-m.p. steryl esters were soluble in rapeseed oil even at a final concentration of 10%. PMID:15638248

  10. Degradation of Jatropha curcas phorbol esters derived from Jatropha oil cake and their tumor-promoting activity.

    Nakao, Motoyuki; Hasegawa, Go; Yasuhara, Tadashi; Ishihara, Yoko

    2015-04-01

    Large amount of oil cake is generated during biodiesel production from Jatropha seeds. Although Jatropha oil cake is rich in plant nutrients, presence of toxic phorbol esters restricts the usage of oil cake as a fertilizer. The objective of this study is to evaluate the components and tumor promoting activity of phorbol esters in Jatropha oil cake-supplemented soil and plants grown in the treated soil. Contents and their biological activity of Jatropha phorbol esters in soil and plants were sequentially analyzed by high-performance liquid chromatography (HPLC) and in vitro cell transformation assay, respectively. Disappearance of Jatropha phorbol-ester-specific peaks were followed with HPLC during incubation of Jatropha oil cake with soil for five weeks. Along with the degradation of Jatropha phorbol ester in soil, tumor-promoting activity in the sample was also attenuated and ultimately disappeared. Jatropha phorbol esters and tumor promoting activity were not detected from mustard spinach grown in the Jatropha oil cake-supplemented soil. In addition, the esterase KM109 degrades DHPB (see definition below; Jatropha phorbol ester) and reduced its tumor-promoting activity. From these data, we conclude: (1) components and tumor promoting activity of Jatropha phorbol esters in the oil cake disappeared completely by incubation with soil for five-week, (2) Jatropha phorbol esters did not transfer into plants grown in the Jatropha oil cake-supplemented soil, and (3) DHPB can be degraded by esterase from soil bacterium. These observations are useful for utilization of Jatropha oil cake as a fertilizer. PMID:25066610

  11. ESTER - a European source term evaluation system

    The Commission of the European Communities (CEC) sponsors considerable model development and validation in the area of Light Water Reactor (LWR) source term, and naturally wishes to see the results used as widely as possible. It also has a role in fostering collaboration between European teams involved in source term analysis, for which purpose Phebus-Fission Product (FP) is acting as a focal point. To further both aims the Joint Research Centre (JRC) decided in 1989 to sponsor the development of the best-estimate code ESTER, which is both a software environment and a set of coupled source term modules which when completed should offer potentialities not currently available within Europe. This paper describes first the overall architecture of ESTER, then the component parts: the tools and services, the user interface, and the modules which perform the physics and chemistry calculations, emphasizing the design choices which have been made. The quality assurance system for the whole system is also reviewed. Contributions from the model developers, both underway, and expected, are then surveyed in the context of the overall development of ESTER, and the planning of the creation and extension of ESTER is given. The paper closes with some proposals for sharing ESTER within Europe and for ensuring its maintenance and continued rational development. (Author)

  12. Anaerobic degradation kinetics of a cholesteryl ester.

    Gutiérrez, S; Viñas, M

    2003-01-01

    The most important components of wool scouring effluent grease are esters of sterols. Cholesteryl palmitate (CP) is the main ester in this grease. In this paper, the influence of the ester concentration in the anaerobic digestion and the relative rate of the different degradation steps, are studied. The experiment was carried out to measure methane production in the anaerobic degradation of acetate, palmitic acid (PA) and CP. A first-order kinetic model was assumed for hydrolysis and Monod models were assumed for both the methanogenic and acetogenic steps. Maximum hydrolysis rate was found to be around 20 times faster than the maximum methanogenic reaction rate during the experience. The lanolin emulsion drop size effect was also evaluated employing fine and coarse stock lanolin emulsions and no adapted sludge. Concentrations of 13.7 to 4.6 gCOD x l(-1) were employed. In a previous study, the effect of palmitic acid emulsion size was found important when similar sludge was tested. When esters are degraded, a significant effect of drop size on the degradation rate was not found. The difference between CP and PA emulsions behavior could be due to the fact that cholesterol produced during the ester degradation has a protective effect on the sludge. PMID:14640211

  13. Synthesis of bioreductive esters from fungal compounds.

    Weerapreeyakul, Natthida; Anorach, Rutchayaporn; Khuansawad, Thidarut; Yenjai, Chavi; Isaka, Masahiko

    2007-06-01

    Four new bioreductive esters (7-10) have been synthesized. Their structures composed of trimethyl lock containing quinone propionic acid with an ester linkage to the fungal cytotoxic compounds; preussomerin G (1), preussomerin I (2), phaseolinone (3) and phomenone (4). The synthesized esters are aimed to act via reductive activation specifically at the cancer cells, resulting from hypoxia and overexpression of reductases. Hence, the toxicity will be lessened during distribution across the normal cells. The anticancer activity was determined in cancer cell lines with reported reductase i.e., BC-1 cells and NCI-H187 as well as in non-reductase containing cancer cells; KB cells. When considering each cell lines, result showed that structure modification giving to 7-10 led to less cytotoxicity than their parent compounds (1-4). Both 7 and 8 were strongly cytotoxic (IC50 < or = 5 microg/ml) to NCI-H187, whereas 9 and 10 were moderately cytotoxic (IC50 = 6-10 microg/ml) to BC-1 cells. Additional study of stability of represented phenolic ester (8) and an alcoholic ester (9) were performed. Result illustrated that both 8 and 9 were stable in the presence of esterase. Therefore, the cytotoxicity of the synthesized compounds (8-10) might be due to partial bioreductive activation in the cancer cells. PMID:17541198

  14. Adsorption and desorption of herbicide monosulfuron-ester in Chinese soils

    Chunxian Wu; Suzhi Zhang; Guo Nie; Zhongming Zhang; Jinjun Wang

    2011-01-01

    Monosulfuron-ester is a new,low rate,sulfonylurea herbicide that is being promoted for annual broadleaf and gramineal weed control; however,there is a lack of published information on its behavior in soils.The adsorption and desorption of monosulfuronester by seven type soils were measured using a batch equilibrium technique.The results showed that the Freundlich equation fitted its adsorption and desorption well,and the Freundlich constant values (Kf-~) ranged from 0.88 to 5.66.Adsorption isotherms were nonlinear with l/nf-ads values < 1.Soil pH,organic matter (OM),and clay content were the main factors influencing its adsorption and desorption.Adsorption and desorption were negatively correlated with pH 4.0-8.0 while positively correlated with OM and clay content.The adsorption of monosulfuron-ester was mainly a physical process,because its free energy (ΔG) in seven soils was less than 40 kJ/mol.Monosulfuron-ester adsorption by three soils increased with increasing CaCl2 concentration using CaCl2 as a background electrolyte.Monosulfuron-ester desorption was hysteretic in all tested soils.

  15. Determination of 16 Phthalate Esters Migrants Content in Infant Milk Powder by GC-MS%气相色谱-质谱法测定婴幼儿乳粉中16种邻苯二甲酸酯类迁移物

    王守法; 周耀斌; 宁啸骏; 刘畅; 葛宇

    2013-01-01

    A suitable GC-MS method was established for the determination of 16 phthalate estersmigrants in infant milk powder.With ultrapure water to redissolve the phthalate esters in infant milk powder,with n-hex-ane to extract and purify them,then used GC-MS to quantitative analyze them with SIMmode.16 phthalate es-ters showed good linear relationships in concentration range of 0.2 to 5.0mg/kg,the recoveries of phthalate es-ters added in infant milk powder ranged from 75.0% to 107.6%,the correlation coefficientswere larger than 0.996,relative standard deviations (RSD)were 0.68% to 6.10%.This method is simple,short time spend-ing and with good reproducibility,it is suitable for the determination of 16 phthalate esters in infant milk pow-der.%建立了一种同时测定婴幼儿乳粉中16种邻苯二甲酸酯类迁移物的气相色谱-质谱(GC-MS)检测方法。采用超纯水将婴幼儿乳粉中的邻苯二甲酸酯类物质复溶,通过正己烷提取净化后采用气相色谱-质谱选择离子检测模式(SIM)进行定量分析。当加标水平在0.2~5.0mg/kg 时,16种邻苯二甲酸酯类物质均呈现良好的线性关系,相关性系数均大于0.995。回收率为75.0%~107.6%,相对标准偏差(RSD)为0.68%~6.10%。该方法操作简便、检测时间短、重现性好,适用于同时检测婴幼儿乳粉中16种邻苯二甲酸酯类物质。

  16. Affinity labelling enzymes with esters of aromatic sulfonic acids

    Wong, Show-Chu; Shaw, Elliott

    1977-01-01

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

  17. Long-lived testosterone esters in the rat.

    Borg, W; Shackleton, C. H.; Pahuja, S L; Hochberg, R B

    1995-01-01

    Over the past decade it has become increasingly clear that steroid hormones are enzymatically esterified with fatty acids. These steroidal esters are the natural analogs of synthetic esters that are used therapeutically. One such family of pharmacological steroids is the synthetic alkyl esters of testosterone, androgens with great hormonal potency. We have investigated whether testosterone esters exist naturally by using the rat as a model. Most tissues of male rats, including blood, have ver...

  18. Acrylic Acid and Esters Will Be Oversupply

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  19. Correlation and prediction of mixing thermodynamic properties of ester-containing systems: Ester + alkane and ester + ester binary systems and the ternary dodecane + ethyl pentanoate + ethyl ethanoate

    Highlights: ► Excess enthalpies and volumes were measured for ester–ester–alkane. ► Mixing behaviour for ester–ester, ester–alkane and ester–ester–alkane are analyzed. ► Correlations with a new polynomial model reproduce well the mixing properties. ► UNIFAC predictions for hE result acceptable excluding the ester–ester mixtures. - Abstract: Excess thermodynamic properties VmE and HmE, have been measured for the ternary mixture dodecane + ethyl pentanoate + ethyl ethanoate and for the corresponding binaries dodecane + ethyl pentanoate, dodecane + ethyl ethanoate, ethyl pentanoate + ethyl ethanoate at 298.15 K. All mixtures show endothermic and expansive effects. Experimental results are correlated with a suitable equation whose final form for the excess ternary quantity ME contains the particular contributions of the three binaries (i–j) and a last term corresponding to the ternary, all of them obtained considering fourth-order interactions. The fit goodness for all mixtures is good and comparable to others equations taken from the literature. In this work the dissolution model for the binaries and ternary is analyzed with a special attention to ester–ester binaries whose behaviour is discussed. The application of the UNIFAC group contribution model to estimate the HmE yields acceptable results for the binaries (with the exception of ester–ester) and for the ternary mixture.

  20. Technetium and rhenium tracers with metabolizable ester functions

    Re-DMSA (dimercaptosuccinic acid) ester complexes were prepored by ligand exchange reactions. To determine whether the ester band in Re-DMSA ester complexes is susceptible to cleavage by esterases, incubation experiments with tissue homogenates and plasma were carried out. (BBR)

  1. 40 CFR 721.3085 - Brominated phthalate ester.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated phthalate ester. 721.3085... Substances § 721.3085 Brominated phthalate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated phthalate ester (PMN P-90-581)...

  2. 21 CFR 175.210 - Acrylate ester copolymer coating.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  3. Ester Tuiksoo - Eesti esimene naissoost põllumajandusminister / Ester Tuiksoo ; interv. Toomas Verrev

    Tuiksoo, Ester, 1965-

    2007-01-01

    Ametist lahkuv põllumajandusminister Ester Tuiksoo räägib saadud juhtimiskogemusest, Euroopa Liidu ühise põllumajanduspoliitika juurutamisest, rahvuskala valimisest, Rahvaliidu käekäigust parlamendivalimistel

  4. Acceleration effect of ionic liquids on polycyclotrimerization of dicyanate esters

    A. Fainleib

    2016-09-01

    Full Text Available The polycyclotrimerization reaction of dicyanate ester of bisphenol E (DCBE in the presence of varying amounts (from 0.5 to 5 wt% of 1-octyl-3-methylimidazolium tetrafluoroborate ([OMIm][BF4] ionic liquid has been investigated using differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR techniques, after a curing stage at 150 °C for 6 h. It is noteworthy that an amount of [OMIm][BF4] as low as 0.5 wt% accelerates dramatically the thermal curing process leading to the formation of a polycyanurate network. The conversion of DCBE increased with increasing [OMIm][BF4] content in the temperature range studied. A reaction mechanism associated with the ionic liquid-catalyzed DCBE polycyclotrimerization is newly proposed via the involvement of a [CN]δ+–[OMIm]δ– complex as a key intermediate.

  5. Half esters and coating compositions comprising reactions products of half esters and polyepoxides

    Blaauw, R; Mulder, W J; Koelewijn, R.; Boswinkel, G.

    2006-01-01

    The present invention relates to half esters based on dicarboxylic acid derivatives and dimer fatty diols, wherein the dimer fatty dio ls are based on dimerised and/or trimerised and/or oligomerised unsaturated fatty acids. The present invention further relates to resin compositions based on the half ester and an polyepoxide. The resin composition can be used in high solids coatings, inks, adhesives, wall covering products, flooring products and plastic products

  6. Expanding the modular ester fermentative pathways for combinatorial biosynthesis of esters from volatile organic acids.

    Layton, Donovan S; Trinh, Cong T

    2016-08-01

    Volatile organic acids are byproducts of fermentative metabolism, for example, anaerobic digestion of lignocellulosic biomass or organic wastes, and are often times undesired inhibiting cell growth and reducing directed formation of the desired products. Here, we devised a general framework for upgrading these volatile organic acids to high-value esters that can be used as flavors, fragrances, solvents, and biofuels. This framework employs the acid-to-ester modules, consisting of an AAT (alcohol acyltransferase) plus ACT (acyl CoA transferase) submodule and an alcohol submodule, for co-fermentation of sugars and organic acids to acyl CoAs and alcohols to form a combinatorial library of esters. By assembling these modules with the engineered Escherichia coli modular chassis cell, we developed microbial manufacturing platforms to perform the following functions: (i) rapid in vivo screening of novel AATs for their catalytic activities; (ii) expanding combinatorial biosynthesis of unique fermentative esters; and (iii) upgrading volatile organic acids to esters using single or mixed cell cultures. To demonstrate this framework, we screened for a set of five unique and divergent AATs from multiple species, and were able to determine their novel activities as well as produce a library of 12 out of the 13 expected esters from co-fermentation of sugars and (C2-C6) volatile organic acids. We envision the developed framework to be valuable for in vivo characterization of a repertoire of not-well-characterized natural AATs, expanding the combinatorial biosynthesis of fermentative esters, and upgrading volatile organic acids to high-value esters. Biotechnol. Bioeng. 2016;113: 1764-1776. © 2016 Wiley Periodicals, Inc. PMID:26853081

  7. Synthesis of 11C labelled methyl esters: transesterification of enol esters versus BF3 catalysed esterification-a comparative study

    C-11 labelled methyl esters have been synthesized via the transesterification of enol esters in the presence of C-11 methanol and 1,3 dichlorodibutylstannoxane as catalyst. This method leaves functional groups intact and allows access to a wider variety of C-11 labelled methyl esters compared to the BF3 catalysed ester formation, which uses carboxylic acids and C-11 methanol as starting materials

  8. Influence of the adipate and dissolved oxygen concentrations on the beta-lactam production during continuous cultivations of a Penicillium chrysogenum strain expressing the expandase gene from Streptomyces clavuligerus

    Robin, Jarno Jacky Christian; Bonneau, S.; Schipper, D.;

    2003-01-01

    The influence of adipate concentration and dissolved oxygen on production of adipoyl-7-aminodeacetoxycephalosporanic acid (ad-7-ADCA) by a recombinant strain of Penicillium chrysogenum expressing the expandase gene from Streptomyces clavuligerus was studied in glucose-limited continuous cultures....... decreased from 15 to 7%AS, r(p) (total) increased to 25 mumol g DW-1 h(-1), mainly due to a two-fold increase in the adipoyl-6-aminopenicillanic acid (ad-6-APA) specific productivity....

  9. Anthropometrische und psychosoziale Prädiktoren für den langfristigen Erfolg einer ambulanten Lifestyleintervention bei übergewichtigen und adipösen Kindern und Jugendlichen

    Fröhlich, Georg

    2010-01-01

    Einleitung: Der Effektivitätsnachweis einer ambulanten Therapie von übergewichtigen und adipösen Kindern und Jugendlichen ist in der Vergangenheit mehrfach erbracht worden und weist zufriedenstellende Ergebnisse auf. Dennoch ist die Behandlung kontinuierlich zu verbessern. Diesbezüglich sind Teilnehmermerkmale, sog. Prädiktoren, zu eruieren, die den langfristigen Erfolg und die postinterventionelle BMI-SDS Entwicklung beschreiben. Methode: An der einjährigen ambulanten multimodalen Therapi...

  10. Biodegradation of poly(lactic acid), poly(hydroxybutyrate-co-hydroxyvalerate), poly(butylene succinate) and poly(butylene adipate-co-terephthalate) under anaerobic and oxygen limited thermophilic conditions

    Jutakan Boonmee; Charnwit Kositanont; Thanawadee Leejarkpai

    2016-01-01

    In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid) (PLA), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), poly(butylene succinate) (PBS), and poly(butylene adipate-co-terephthalate) (PBAT) were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of b...

  11. Experimental investigation on a diesel engine using neem oil and its methyl ester

    Sivalakshmi S.; Balusamyb T.

    2011-01-01

    Fuel crisis and environmental concerns have led to look for alternative fuels of bio-origin sources such as vegetable oils, which can be produced from forests, vegetable oil crops and oil bearing biomass materials. Vegetable oils have energy content comparable to diesel fuel. The effect of neem oil (NeO) and its methyl ester (NOME) on a direct injected four stroke, single cylinder diesel engine combustion, performance and emission is investigated in this paper. The results show that at ...

  12. Thermally cured coil-coatings utilizing novel resins and fatty acid methyl esters as reactive diluents

    Johansson, Katarina

    2008-01-01

    Solvent-borne thermally cured coil-coating resins contain large amounts of volatile organic solvents in order to obtain suitable flow for film application. This work describes how the expensive and environmental hazardous volatile organic solvent content of a solvent-borne thermally cured polyester/melamine coil-coating system can be reduced by introduction of fatty acid methyl esters (FAMEs) as reactive diluents and modification of the polyester binder resin. The evaluated reactive diluents,...

  13. GC-MS ANALYSIS OF THE FATTY ACID METHYL ESTER IN JAPANESE QUAIL FAT

    Ion Dragalin; Olga Morarescu; Maria Sedcenco; Radu Marin Rosca

    2015-01-01

    The accumulated as production waste fat from Faraon quail breeds has been investigated for the first time by using GC-MS technique, preventively converting it via methanolysis to fatty acid methyl esters. The test results, regarding the content of unsaturated fatty acids having a favorable to human body cis-configuration (77.8%), confirm their nutritional value and the possibility of using this fat in cosmetic, pharmaceutical and food industries.

  14. GC-MS ANALYSIS OF THE FATTY ACID METHYL ESTER IN JAPANESE QUAIL FAT

    Ion Dragalin

    2015-12-01

    Full Text Available The accumulated as production waste fat from Faraon quail breeds has been investigated for the first time by using GC-MS technique, preventively converting it via methanolysis to fatty acid methyl esters. The test results, regarding the content of unsaturated fatty acids having a favorable to human body cis-configuration (77.8%, confirm their nutritional value and the possibility of using this fat in cosmetic, pharmaceutical and food industries.

  15. Astaxanthin, canthaxanthin and astaxanthin esters in the copepod Acartia bifilosa (Copepoda, Calanoida) during ontogenetic development

    Maria £otocka; Ewa Styczynska-Jurewicz

    2001-01-01

    The contents of astaxanthin, canthaxanthin and astaxanthin esters were studied in natural populations of the copepod Acartia bifilosa from the Pomeranian Bay and Gulf of Gdansk in the southern Baltic Sea. Samples dominated by any one of three developmental groups: (1) nauplii, (2) copepodids I-III and (3) copepodids IV-V and adults of Acartia bifilosa were analysed by means of high performance liquid chromatography (HPLC). As ontogenetic development progressed, significant changes occurre...

  16. Production of ethyl ester from esterified crude palm oil by microwave with dry washing by bleaching earth

    Suppalakpanya, K.; Ratanawilai, S.B.; Tongurai, C. [Department of Chemical Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand)

    2010-07-15

    The production of ethyl ester from a feed material of esterified crude palm oil with 1.7 wt% of free fatty acid (FFA) content using microwave heating was investigated. Parametric studies were carried out to investigate the optimum conditions for the transesterification process (amount of ethanol, amount of catalyst and reaction time). As a result, optimum reaction parameters for the transesterification process aided by microwave heating have been identified: a molar ratio of oil to ethanol of 1:8.5, 1.5 wt% of KOH/oil, a reaction time of 5 min and a microwave power of 70 W. Glycerin from the ester phase was separated by adding 10 wt% of pure glycerin. The ethyl ester was purified with 1.2 wt% of bleaching earth to remove the residual catalyst and residual glycerin. This transesterification process provided a yield of 85 wt% with an ester content of 98.1 wt%. The final ethyl ester product met the specifications stipulated by ASTM D6751-02. (author)

  17. Stability and changes in astaxanthin ester composition from Haematococcus pluvialis during storage

    Miao, Fengping; Geng, Yahong; Lu, Dayan; Zuo, Jincheng; Li, Yeguang

    2013-11-01

    In this paper, we investigated the effects of temperature, oxygen, antioxidants, and corn germ oil on the stability of astaxanthin from Haematococcus pluvialis under different storage conditions, and changes in the composition of astaxanthin esters during storage using high performance liquid chromatography and spectrophotometry. Oxygen and high temperatures (22-25°C) significantly reduced the stability of astaxanthin esters. Corn germ oil and antioxidants (ascorbic acid and vitamin E) failed to protect astaxanthin from oxidation, and actually significantly increased the instability of astaxanthin. A change in the relative composition of astaxanthin esters was observed after 96 weeks of long-term storage. During storage, the relative amounts of free astaxanthin and astaxanthin monoesters declined, while the relative amount of astaxanthin diesters increased. Thus, the ratio of astaxanthin diester to monoester increased, and this ratio could be used to indicate if astaxanthin esters have been properly preserved. If the ratio is greater than 0.2, it suggests that the decrease in astaxanthin content could be higher than 20%. Our results show that storing algal powder from H. pluvialis or other natural astaxanthin products under vacuum and in the dark below 4°C is the most economical and applicable storage method for the large-scale production of astaxanthin from H. pluvialis. This storage method can produce an astaxanthin preservation rate of at least 80% after 96 weeks of storage.

  18. Evaluation of iodination on the ethyl ester of poppy seed oil fatty acid by NAA method

    Evaluation of iodination on the ethyl ester of poppy seed oil fatty acid by NAA method. Poppy seed oil has been known for having unsaturated bonds. Therefore, the addition of iodine is expected to give a poly-iodo organic compound which can be used for roentgenography diagnosis. However, since the oil has a high viscosity which is not suitable for the mentioned purpose it must be changed into its simple ester prior to the iodination. It was observed that there was no significant change in the double bonds of the alkyl chain, and the reaction yield was also satisfactory. A preliminary experiment showed that direct iodination using I2 on the ethyl ester did not proceed well. Therefore a iodobromination of the ethyl ester was carried out followed by exchange reaction with I2 in chloroform. The evaluation using NAA method appeared to show that exchange reaction between Br in the iodobrominated compound and I in the I2 could proceed well. However, determination of the iodine content did not agree with that of the bromine. It might be caused by the instability of the compounds. It was also observed that I2 liberated from compounds diffused and penetrated the polyethylene material used for sample purse in the neutron activation. (author). 16 refs.; 4 figs

  19. Effect of emulsion properties on release of esters under static headspace, in vivo, and artificial throat conditions in relation to sensory intensity

    Weel, K.G.C.; Boelrijk, A.E.M.; Burger, J.J.; Jacobs, M.A.; Gruppen, H.; Voragen, A.G.J.; Smit, G.

    2004-01-01

    The effects of oil content and droplet size distributions of dilute oil-in-water emulsions on release of four esters with different hydrophobicities were studied under in vivo, static headspace, and artificial throat conditions. The effect of oil content on orthonasal and retronasal perceived intens

  20. Atmospheric oxidation of selected alcohols and esters

    Becker, K.H.; Cavalli, F.

    2001-03-01

    The decision whether it is appropriate and beneficial for the environment to deploy specific oxygenated organic compounds as replacements for traditional solvent types requires a quantitative assessment of their potential atmospheric impacts including tropospheric ozone and other photooxidant formation. This involves developing chemical mechanisms for the gasphase atmospheric oxidation of the compounds which can be reliably used in models to predict their atmospheric reactivity under a variety of environmental conditions. Until this study, there was very little information available concerning the atmospheric fate of alcohols and esters. The objectives of this study were to measure the atmospheric reaction rates and to define atmospheric reaction mechanisms for the following selected oxygenated volatile organic compounds: the alcohols, 1-butanol and 1-pentanol, and the esters, methyl propionate and dimethyl succinate. The study has successfully addressed these objectives. (orig.)

  1. Photoenolization of o-Methylvalerophenone Ester Derivative.

    Das, Anushree; Lao, Emily A; Gudmundsdottir, Anna D

    2016-05-01

    Photolysis of ester 1 in argon-saturated methanol and acetonitrile does not produce any product, whereas irradiation of 1 in oxygen-saturated methanol yields peroxide 2. Laser flash photolysis studies demonstrate that 1 undergoes intramolecular H atom abstraction to form biradical 3 (λmax ~340 nm), which intersystem crosses to form photoenols Z-4 and E-4 (λmax ~380 nm). Photoenols 4 decay by regenerating ester 1. With the aid of density functional theory calculations, it was concluded the photoenol E-4 does not undergo spontaneous lactonization or electrocyclic ring closure because the transition state barriers for these reactions are too large to compete with reketonization of E-4 to form 1. PMID:27061950

  2. Naturally occurring antifungal aromatic esters and amides

    During the search of antifungal natural products from terrestrial plants, a new long chained aromatic ester named grandiflorate along with spatazoate from Portulaca grandiflora and N-[2-methoxy-2-(4-methoxyphenyl) ethyl]-trans-cinnamide and aegeline from Solanum erianthum of Nigeria were isolated and tested against six fungal species. The known constituents have not been reported so far from mentioned investigated plants. Structures of the isolated compounds were elucidated with the aid of spectroscopic techniques including two dimensional NMR experiments. Among the compounds, the esters found more potent than amides against Candida albicans and Aspergillus flavus. The new compound grandiflorate gave response against all tested fungal species while aegeline was found to give lowest inhibition during this study. (author)

  3. Gas chromatographic retention data of wax esters

    Stránský, Karel; Zarevúcka, Marie; Valterová, Irena; Wimmer, Zdeněk

    2006-01-01

    Roč. 1128, č. 1/2 (2006), s. 208-219. ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA203/04/0120; GA AV ČR(CZ) IAA4055403 Institutional research plan: CEZ:AV0Z40550506 Keywords : Wax esters * gas chromatography * Kováts index * Reduced Kováts index Subject RIV: CC - Organic Chemistry Impact factor: 3.554, year: 2006

  4. Synthesis of ester-siloxane multiblock copolymers

    Antić Vesna V.; Vučković Marija V.; Govedarica Milutin N.

    2004-01-01

    It was shown that the two-stage transesterification/polycondensation reaction in the melt, can successfully be applied for the preparation of poly(butylene terephtalate-dimethylsiloxane) multiblock copolymers. Three series of co-polymers were synthesized, using poly(dimethylsiloxanes) bearing ester (two series) and hydroxy -end groups as reactants. The structure and composition of the obtained copolymers were determined by 1H NMR spectroscopy A mechanism, i.e. an order of reaction steps, invo...

  5. Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

    Hua, Lei; Liu, Jian-hua; Li, Song-mei; Yu, Mei; Wang, Lei; Cui, Yong-xin

    2015-03-01

    The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25°C and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10-20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.

  6. Active biodegradable films produced with blends of rice flour and poly(butylene adipate co-terephthalate): effect of potassium sorbate on film characteristics.

    Sousa, G M; Soares Júnior, M S; Yamashita, F

    2013-08-01

    The objective of work was to produce and characterize biodegradable films from rice flour, poly(butylene adipate co-terephthalate) (PBAT), glycerol and potassium sorbate, for application as active packaging for fresh lasagna pasta. The films were evaluated with respect to their optical, water vapor barrier, mechanical and microstructural properties. The mechanical properties and microstructure were evaluated after use as packaging material for fresh pasta for 45 days at 7°C. The blends of rice flour, PBAT, glycerol and potassium sorbate showed good processability and allowed for the pilot scale production of films by blow extrusion process. The addition of 1 to 5% potassium sorbate as plasticizer agent of films in place of glycerol did not alter the film mechanical properties and a sorbate concentration greater or equal than 3% reduced the opacity, although increasing the water vapor permeability. The films could be used as active packaging for fresh food pasta, since they remained integral and easy to handle after application. The rice flour was shown to be an excellent material for the formulation of biodegradable films, since it is a low-cost raw material from a renewable source. The addition of potassium sorbate did not affect the extrusion process, and could be used in the production of packaging for use with foods. PMID:23706195

  7. Effect of Chain-Extenders on the Properties and Hydrolytic Degradation Behavior of the Poly(lactide/ Poly(butylene adipate-co-terephthalate Blends

    Mingqing Chen

    2013-10-01

    Full Text Available Biodegradable poly(lactide/poly(butylene adipate-co-terephthalate (PLA/PBAT blends were prepared by reactive blending in the presence of chain-extenders. Two chain-extenders with multi-epoxy groups were studied. The effect of chain-extenders on the morphology, mechanical properties, thermal behavior, and hydrolytic degradation of the blends was investigated. The compatibility between the PLA and PBAT was significantly improved by in situ formation of PLA-co-PBAT copolymers in the presence of the chain-extenders, results in an enhanced ductility of the blends, e.g., the elongation at break was increased to 500% without any decrease in the tensile strength. The differential scanning calorimeter (DSC results reveal that cold crystallization of PLA was enhanced due to heterogeneous nucleation effect of the in situ compatibilized PBAT domains. As known before, PLA is sensitive to hydrolysis and in the presence of PBAT and the chain-extenders, the hydrolytic degradation of the blend was evident. A three-stage hydrolysis mechanism for the system is proposed based on a study of weight loss and molecular weight reduction of the samples and the pH variation of the degradation medium.

  8. Investigation on Polylactide (PLA/Poly(butylene adipate-co-terephthalate (PBAT/Bark Flour of Plane Tree (PF Eco-Composites

    Qiang Dou

    2016-05-01

    Full Text Available Polylactide (PLA/poly(butylene adipate-co-terephthalate (PBAT/bark flour of plane tree (PF eco-composites were prepared via melt blending. The morphologies, mechanical properties, crystal structures and melting and crystallization behaviors of the eco-composites were investigated by means of scanning electron microscopy (SEM, mechanical tests, polarized light microscopy (PLM, wide angle X-ray diffraction (WAXD and differential scanning calorimetry (DSC, respectively. It is shown that the interfacial adhesion between PLA matrix and PF is weak and the mechanical properties of PLA/PF eco-composites are poor. The titanate treatment improves the adhesion between the matrix and the filler and enhances the stiffness of the eco-composites. The toughness is improved by PBAT and ductile fractured surfaces can be found. The spherulitic size of PLA is decreased by the addition of PF. The α crystalline form of PLA remains in the composites. Compared with PF, T-PF (PF treated by a titanate coupling agent and PBAT have negative effects on the crystallization of PLA.

  9. Mechanical properties and morphology of biodegradable poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends compatibilized by transesterification

    Highlights: ► Compatibility between PLA and PBAT is improved through transesterification. ► Elongation at break of PLA was up to almost 300%. ► Both toughness and stiffness of PLA/PBAT blends are improved significantly after the incorporation of TBT. -- Abstract: Biodegradable poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends with various tetrabutyl titanate (TBT) concentration were prepared through melt-extrusion. Mechanical properties and morphology were characterized in terms of tensile and impact testing, dynamical mechanical analysis and scanning electron micrograph (SEM). The results indicated that the overall mechanical properties (including tensile strength, elongation at break, toughness and stiffness) of PLA/PBAT blends can be improved significantly after the incorporation of TBT. The SEM micrographs demonstrated that the compatibility and strong interaction between PLA and PBAT was improved via transesterification during melt-extrusion. The interfacial debonding, pullout of PBAT, yielding deformation were the most important mechanisms to improve toughness.

  10. Ethyl ester production from (RBD palm oil

    Oscar Mauricio Martínez Ávila

    2010-07-01

    Full Text Available This work develops a methodology for obtaining ethyl esters from RBD (refined, bleached and deodorised palm oil by evaluating the oil’s transesterification and separation. Two catalysts were first tested (KOH and NaOH by studying the effect of water presence on the reaction. The separation process was then evaluated by using water and water-salt and water-acid mixtures, establishing the agent offering the best results and carrying out the purification stage. Raw materials and products were characterised for comparing the latter with those obtained by traditional means and verifying the quality of the esters so produced; minimum differences were found bet-ween both. The proposed methodology thus allows esters to be used as raw material in petrochemical industry applications. A more profitable process can be obtained compared to those used today, given the amounts of separation agent so established (1% H3PO4 solution, in water. The overall process achieved 74.4% yield, based on the oil being used.

  11. Lipase-Catalyzed Synthesis and Characterization of 6-O-(11-Dodecenoic)-Glucose Ester in Ionic Liquids

    Yuan-An Wei; Qunliang Li; Xin Zhang; Guang-Jun Huang; Wei Yan; Ping-Jia Yao

    2012-01-01

    Novozym-435 Lipase-catalyzed transesterification of glucose with 11-dodecenoic ethyl ester in ionic liquids was investigated. The effect of substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in 1-buty-3-methyl imidazolium tetrafluoroborate [Bmim][BF4] under such conditions as the reaction temperature of 55℃, the enzyme concentration of 20 mg/mL, the mole ratio of glucose/11-dodecenoic ethyl e...

  12. Pengaruh Katalis H2SO4 pada Reaksi Epoksidasi Metil Ester PFAD (Palm Fatty Acid Distillate)

    Sinaga, Mersi Suriani

    2010-01-01

    Ester epoksi selain sebagai pelunak juga dapat memperbaiki ketahanan komponen polivinil klorida (PVC) terhadap panas dan cahaya. Penelitian ini dilakukan untuk merumuskan kondisi katalis yang sesuai bagi pembuatan senyawa epoksi metil ester PFAD dari senyawa metil ester PFAD. Metil ester PFAD terdiri dari ester lemak jenuh dan tidak jenuh., metode pemisahan kristalisasi dengan pelarut metanol untuk memisahkan ester lemak jenuh dari ester lemak tak jenuh, yang bertujuan meningkatkan kemamp...

  13. Possibilities of the use of camelina and mustard methyl esters and their mixtures with diesel as a fuel for compression ignition engines

    Marta Ambrosewicz-Walacik

    2015-03-01

    Full Text Available The aim of the study was to evaluate the use of camelina and mustard methyl esters and their mixtures with diesel (in 95:5 and 80:20 proportion as fuels for compression ignition engines. Esters prepared with acid-base transesterification process methyl were characterized in terms of the lipid composition, kinematic viscosity at 40°C, density at 15°C, acid value, particulate matter content, sulphur content, flash point, cold filter plugging point and oxidative stability at 110°C. It has been shown that the majority of the analysed methyl esters discriminates, with the exception of the particulate matter content, meet the requirements of PN-EN 14214 (2012. In case of methyl ester and ON mixtures it has been found that the 5% addition of esters slightly contributed to the changes in physic-chemical properties, compared to diesel fuel, while 20% addition resulted in an increase of value of the tested discriminates. In general, it has been also found that the only discriminates disqualifying the usage of those samples as fuels for diesel engines was too high particulate matter content.

  14. Environmentally friendly properties of vegetable oil methyl esters

    Gateau Paul

    2005-07-01

    Full Text Available Measurements were carried out on Vegetable Oil Methyl Esters (VOME or FAME answering the most recent specifications. The products tested are RME (Rapeseed oil Methyl Ester, ERME (Erucic Rapeseed oil Methyl Esters, SME (Sunflower oil Methyl Esters, and HOSME (High Oleic Sunflower oil Methyl Esters. They contain more than 99.5% of fatty acid mono esters. The compositions are given. VOME are not volatile and they are not easily flammable. They are not soluble in water and they are biodegradable. According to the methods implemented for the determination of the German classification of substances hazardous to waters WGK, they are not toxic on mammals and unlike diesel fuel they are not toxic on fish, daphnia, algae and bacteria. The RME is not either toxic for shrimps. According to tests on rabbits, RME and SME are not irritating for the skin and the eyes. VOME display particularly attractive environmental properties.

  15. Synthesis, Characterization and Properties of Vinyl Ester Matrix Resins

    Li, Hui III

    1998-01-01

    Vinyl ester oligomers diluted with styrene are important matrix resins for thermosetting polymer composites. A major objective of this work has been to study the chemistry and kinetics of the cure reactions of vinyl ester resins at elevated curing temperatures, which are consistent with typical composite processing conditions. The crosslinking reaction of vinyl ester resins was studied by FTIR and the loss of the carbon-carbon double bonds of the methacrylate (943 cm-1) and styrene (910 cm-1...

  16. Stanol esters attenuate the aggravating effect of dietary cholesterol on atherosclerosis in homozygous Watanabe rabbits

    Schrøder, Malene; Husche, Constanze; Pilegaard, Kirsten;

    2009-01-01

    Plant stanols are marketed as natural means to lower blood cholesterol in humans; hence the effect on combined familial hyperlipidemia is not known. The objective was to investigate the effect of stanol esters on blood lipids and aortic atherosclerosis in homozygous WHHL rabbits challenged with...... dietary cholesterol. A total of 36 rabbits, 6 weeks of age, with initial plasma cholesterol of 22.5 mmol/L were assigned to two treatment groups fed a standard rabbit chow with 1 g/kg cholesterol or this diet added 34 g/kg stanol ester, respectively, for 16 weeks. Plasma cholesterol was measured initially...... and at termination, also in lipoproteins. Aortic atherosclerosis was evaluated as cholesterol content and area covered by plaque. Plasma cholesterol was not significantly different between the groups at termination (35.7 mmol/L vs. 35.5 mmol/L). A significant increase in LDL was seen (13.1 mmol/L vs...

  17. Transesterification of mustard (Brassica nigra) seed oil with ethanol: Purification of the crude ethyl ester with activated carbon produced from de-oiled cake

    Highlights: • Biodiesel ethyl ester has been developed from mustard seed oil. • Variables affect the transesterification were investigated. • Dry washing using the activated carbon produced from the extraction remaining was applied to purify the ethyl esters. • Properties of the produced fuels were measured. • Blending of the produced ethyl ester with petro diesel was also investigated. - Abstract: The present study reports the production of mustard seed oil ethyl esters (MSOEE) through alkali-catalyzed transesterification with ethanol using potassium hydroxide as a catalyst. The influence of the process parameters such as catalyst concentration, ethanol to oil molar ratio, reaction temperature, reaction duration and the catalyst type was investigated so as to find out the optimal conditions for the transesterification process. As a result, optimum conditions for production of MSOEE were found to be: 0.90% KOH wt/wt of oil, 8:1 ethanol to oil molar ratio, a reaction temperature of 60 °C, and a reaction time of 60 min. Dry washing method with (2.50% wt.) of the activated carbon that was produced from the de-oiled cake was used to purify the crude ethyl ester from the residual catalyst and glycerol. The transesterification process provided a yield of 94% w/w of ethyl esters with an ester content of 98.22% wt. under the optimum conditions. Properties of the produced ethyl esters satisfied the specifications prescribed by the ASTM standards. Blending MSOEE with petro diesel was also investigated. The results showed that the ethyl esters had a slight influence on the properties of petro diesel

  18. Tandem transformation of glycerol to esters.

    Sotenko, Maria V; Rebroš, Martin; Sans, Victor S; Loponov, Konstantin N; Davidson, Matthew G; Stephens, Gill; Lapkin, Alexei A

    2012-12-31

    Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g L⁻¹ h⁻¹ of 1,3-propanediol. Biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 75%. A hollow fibre membrane contactor with immobilized Rhizomucor miehei lipase was demonstrated for the continuous tandem fermentation-esterification process. PMID:22796408

  19. Structure-function relationships affecting the insecticidal and miticidal activity of sugar esters.

    Puterka, Gary J; Farone, William; Palmer, Tracy; Barrington, Anthony

    2003-06-01

    bioassays and dosage-mortality data found significant differences among sugar ester compounds' toxicity to the range of arthropod species. Sucrose octanoate high in monoester content had the highest activity against the range of arthropod pests at low concentrations of 1200-2400 ppm. No single chemical structure for the xylitol or sorbitol esters were optimally effective against the range of arthropods we tested and sorbitol octanoate and xylitol decanoate had the highest insecticidal activity of this group. All of the sugar ester materials produced high T. urticae mortalities on apple at very low concentrations of 400 ppm. Overall, most of the sugar esters that were examined had superior insecticidal activity compared with insecticidal soap. Sugar ester chemistry offers a unique opportunity to design an insecticide or miticide specific to certain arthropod pests which would be valuable in crop integrated pest management (IPM) programs. Sucrose esters are currently used as additives in the food industry which makes them especially attractive as safe and effective insecticides. PMID:12852599

  20. Stereoselective Formation of Trisubstituted Vinyl Boronate Esters by the Acid-Mediated Elimination of α-Hydroxyboronate Esters

    Guan, Weiye; Michael, Alicia K.; McIntosh, Melissa L.; Koren-Selfridge, Liza; Scott, John P.; Clark, Timothy B.

    2014-01-01

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

  1. Super-Robust Polylactide Barrier Films by Building Densely Oriented Lamellae Incorporated with Ductile in Situ Nanofibrils of Poly(butylene adipate-co-terephthalate).

    Zhou, Sheng-Yang; Huang, Hua-Dong; Ji, Xu; Yan, Ding-Xiang; Zhong, Gan-Ji; Hsiao, Benjamin S; Li, Zhong-Ming

    2016-03-01

    Remarkable combination of excellent gas barrier performance, high strength, and toughness was realized in polylactide (PLA) composite films by constructing the supernetworks of oriented and pyknotic crystals with the assistance of ductile in situ nanofibrils of poly(butylene adipate-co-terephthalate) (PBAT). On the basis that the permeation of gas molecules through polymer materials with anisotropic structure would be more frustrated, we believe that oriented crystalline textures cooperating with inerratic amorphism can be favorable for the enhancement of gas barrier property. By taking full advantage of intensively elongational flow field, the dispersed phase of PBAT in situ forms into nanofibrils, and simultaneously sufficient row-nuclei for PLA are induced. After appropriate thermal treatment with the acceleration effect of PBAT on PLA crystallization, oriented lamellae of PLA tend to be more perfect in a preferential direction and constitute into a kind of network interconnecting with each other. At the same time, the molecular chains between lamellae tend to be more extended. This unique structure manifests superior ability in ameliorating the performance of PLA film. The oxygen permeability coefficient can be achieved as low as 2 × 10(-15) cm(3) cm cm(-2) s(-1) Pa(-1), combining with the high strength, modulus, and ductility (104.5 MPa, 3484 MPa, and 110.6%, respectively). The methodology proposed in this work presents an industrially scalable processing method to fabricate super-robust PLA barrier films. It would indeed push the usability of biopolymers forward, and certainly prompt wider application of biodegradable polymers in the fields of environmental protection such as food packaging, medical packaging, and biodegradable mulch. PMID:26959220

  2. The mechanics of hyaluronic acid/adipic acid dihydrazide hydrogel: towards developing a vessel for delivery of preadipocytes to native tissues.

    Shoham, Naama; Sasson, Aviad Levi; Lin, Feng-Huei; Benayahu, Dafna; Haj-Ali, Rami; Gefen, Amit

    2013-12-01

    Promising treatment approaches in repairing tissue defects include implementation of regenerative medicine strategies, particularly delivery of preadipocytes to sites where adipose tissue damage needs to be repaired or where fat needs to be generated. In this study, we suggest that the injectable hyaluronic acid/adipic acid dihydrazide (HA/ADH) hydrogel may be an adipose-tissue-like material in terms of biological compatibility as well as mechanical behavior. First, we show that the hydrogel enables and supports growth, proliferation and differentiation of 3T3-L1 preadipocytes. Second, given that adipose tissue is a weight-bearing biological structure, we investigate the large deformation mechanical behavior of the hydrogel with and without embedded preadipocytes, by performing confined and unconfined compression tests and then calibrating a strain energy density (SED) function to the results. Four test groups were examined: (1) Hydrogel specimens right after the preparation without cells, (2) and (3) 3-days-cultured hydrogel specimens with and without cells, respectively, and (4) 6-days-cultured hydrogel specimens with cells. A one-term Ogden SED was found to adequately describe the hyperelastic behavior of the hydrogel specimens in all experimental groups. Importantly, we found that the mechanical properties of the hydrogel, when subjected to compression, are in good agreement with those of native adipose tissue, with the better fit occurring 3-6 days after preparation of the hydrogel. Third, computational finite element studies of the mechanical (stress-strain) behavior of the HA/ADH hydrogel when containing mature adipocytes indicated that the stiffnesses of the constructs were mildly affected by the presence of the adipocytes. Hence, we conclude that injectable HA/ADH hydrogel may serve as a vessel for protecting preadipocytes during, and at a short-term after delivery to native tissues, e.g. in research towards regenerative medicine in tissue reconstructions

  3. VALIDASI MODIFIKASI METODE WEIßHAAR UNTUK ANALISIS 3-MCPD ESTER DALAM MINYAK GORENG SAWIT [Validation of Modified Weißhaar’s Method for 3-MCPD Esters Analysis in Palm Oil

    Tanti Lanovia1,2*

    2014-12-01

    Full Text Available The 3-monochloropropane-1,2-diol (3-MCPD and 3-MCPD esters were found in any type of refined vegetable oil -mostly produced during the refining process- and recognized as emerging food contaminants. Several analytical methods have been developed and one of which was a Weißhaar's method. The study aims to validate the modified Weißhaar's method for analysis of 3-MCPD and 3-MCPD esters in refined palm oil. Ion fragments were used for identification and quantification of 3-MCPD and 3-MCPD-d5. 3-MCPD was determined by GC-MS after released from its ester by transesterification with sodium methoxide and derivatized with phenylboronic acid. The validation showed that liniarity response (r=0.994 was observed from a linear regression by using external standard and internal standard at a concentration range of 0.008 and 0.377 µg mL-1. The LOD of the validated method was 0.06 µg g-1 while its LOQ was 0.20 µg g-1, precision (relative standard deviation, RSD was 6.16%, and accuracy (as percentage of recovery was in the range of 95.83-113.27%. This results indicated that the modified method was valuable and sensitive for detection of 3-MCPD and 3-MCPD esters. Using the validated method, 3-MCPD esters content of a commercial palm oil sample was determined and calculated as the difference between total 3-MCPD and free 3-MCPD, which was 13.24 µg g-1. Total 3-MCPD content of several palm oils were at a concentration range of 13.94-34.52 µg g-1. These results also showed that there was a correlation between 3-MCPD with diacylglyceride (DAG. Samples with DAG content gave a high test results of 3-MCPD with a coefficient of correlation of r=0.752.

  4. List of Article Contents

    Editorial Section

    2014-12-01

    Full Text Available CONTENTS OF ARTICLES Premixed combustion of coconut oil in a hele-shaw cell DOI: 10.14710/ijred.3.3.155-160 155-160 Hadi Saroso, I.N.G. Wardana, Rudy Soenoko, Nurkholis Hamidi   Analysing the potential of retrofitting ultra-low heat loss triple vacuum glazed windows to an existing UK solid wall dwelling DOI: 10.14710/ijred.3.3.161-174 161-174 Saim Memon   Study of Gasohol as Alternative Fuel for Gasoline Substitution: Characteristics and Performances DOI: 10.14710/ijred.3.3.175-183 175-183 Bardi Murachman, Dicky Pranantyo, Eddie Sandjaya Putra   Thermal effects investigation on electrical properties of silicon solar cells treated by laser irradiation DOI: 10.14710/ijred.3.3.184-187 184-187 Ali Pourakbar Saffar, Bahman Deldadeh Barani   Synthesis of Trimethylolpropane Esters of Calophyllum Methyl Esters : Effect of Temperatur and Molar Ratio DOI: 10.14710/ijred.3.3.188-192 188-192 Yeti Widyawati, Ani Suryani, Muhammad Romli, Sukardi Sukardi   Incorporating Root Crops under Agro-Forestry as the Newly Potential Source of Food, Feed and Renewable Energy DOI: 10.14710/ijred.3.3.193-206 193-206 Yudi Widodo, St. A. Rahayuningsih, Nasir Saleh, Sri Wahyuningsih   Solmap: Project In India's Solar Resource Assessment DOI: 10.14710/ijred.3.3.207-216 207-216 Indradip Mitra, Kaushal Chhatbar, Ashvini Kumar, Godugunur Giridhar, Ramdhan Vashistha, Richard Meyer, Marko Schwandt   Thermo-economic Optimization of Solar Assisted Heating and Cooling (SAHC System DOI: 10.14710/ijred.3.3.217-227 217-227 A. Ghafoor, A. Munir   Combustion characteristics of diesel engine using producer gas and blends of Jatropha methyl ester with diesel in mixed fuel mode DOI: 10.14710/ijred.3.3.228-235 228-235 Hifjur Raheman, Debasish Padhee    

  5. Experimental assessment of toxic phorbol ester in oil, biodiesel and seed cake of Jatropha curcas and use of biodiesel in diesel engine

    Highlights: ► In the present study toxic phorbol esters were detected in oil and seed cake of Jatropha curcas but not detected in biodiesel using high performance liquid chromatography (HPLC). ► The quantity of phorbol esters in Jatropha curcas oil and cake were amounted to be 2.12 ± 0.02 mg/g and 0.6 ± 0.01 mg/g respectively. ► As jatropha oil is a potential source for biodiesel preparation, huge amount of oil and cake will be generated and hence need to be handled carefully. ► Upon engine study exhaust pollutant such as hydrocarbon, smoke opacity and carbon monoxide reduced substantially. - Abstract: The present study deals with estimation of toxic phorbol esters in Jatropha curcas oil, cake and biodiesel and performance emission of different blends of biodiesel in diesel engine. The jatropha seed was collected from Chattishgarh, India and oil content of the seed kernel was 56.5%, determined by soxhlet apparatus. The oil was subjected to biodiesel preparation by twin step method of acid esterification followed by alkali transesterification. The total conversion of jatropha oil methyl ester (JOME) after reaction was 96.05% from proton nuclear magnetic resonance (1H NMR) studies. The phorbol esters content of oil, cake and biodiesel was determined by high performance liquid chromatography (HPLC, Waters). The phorbol esters content of the oil was more (2.26 ± 0.01 mg/g) than the cake (0.6 ± 0.01 mg/g) but no phorbol esters peak was detected in biodiesel. The performance and emission study of the fuel blends (JB2, JB5 and JB10) with conventional diesel were tested for their use as substitute fuel for a single cylinder direct injection diesel engine at constant speed (1500 rpm). The emissions such as CO, HC and smoke opacity decreased whereas NOx and BSCF increased with biodiesel blends.

  6. Physical and monolayer film properties of potential fatty ester biolubricants

    Yao, Linxing [Iowa State University; Hammond, Earl G [Iowa State University; Wang, Tong [Iowa State University; Bu, Wei [Ames Laboratory; Vaknin, David [Ames Laboratory

    2014-04-03

    The desire to replace petroleum-based lubricants with alternatives that are environmentally friendly and made from sustainable sources has encouraged the development of biolubricants based on vegetable oils. To be good lubricants, the materials should have low melting points, appropriate viscosity and oxidative stability. In this paper, we report the melting point and viscosity of oleate esters of ethylene glycol, 1,2-propanediol, 2,3-butanediol, and pentaerythritol as well as the decanoate esters of 2,3-butanediol and the 12-methyltetradecanoate esters of 1,2-propanediol. Polyol esters that have a free hydroxy group had lower melting points than the completely esterified polyols, but the completely esterified polyol esters exhibited less change in viscosity with temperature than those having a free hydroxy group. 2, 3-Butanediol monooleate, which melted at -48.6°C shows promise as a biolubricant, but its viscosity index was estimated to be 100. Pentaerythritol oleate esters, with melting points below -10°C and viscosity indices in the range of 170–197, may be suitable candidates as biolubricants. The behavior of esters spread as a monomolecular film at air/water interface may provide insight into the way they behave when spread on metal or polar surfaces, so the pressure-area isotherms of 2,3-butanediol monoleate and selected esters are also reported.

  7. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Carboxylic acid glycidyl esters. 721... Substances § 721.2950 Carboxylic acid glycidyl esters. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as carboxylic acid glycidyl...

  8. The Preparation and Enzymatic Hydrolysis of a Library of Esters

    Sanford, Elizabeth M.; Smith, Traci L.

    2008-01-01

    An investigative case study involving the preparation of a library of esters using Fischer esterification and alcoholysis of acid chlorides and their subsequent enzymatic hydrolysis by pig liver esterase and orange peel esterase is described. Students work collaboratively to prepare and characterize the library of esters and complete and evaluate…

  9. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-06-14

    Methods and systems for making dibasic esters and/or dibasic acids using metathesis are generally disclosed. In some embodiments, the methods comprise reacting a terminal olefin ester with an internal olefin ester in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In some embodiments, the terminal olefin ester or the internal olefin ester are derived from a renewable feedstock, such as a natural oil feedstock. In some such embodiments, the natural oil feedstock, or a transesterified derivative thereof, is metathesized to make the terminal olefin ester or the internal olefin ester.

  10. Chromatographic analyses of fatty acid methyl esters by HPLC-UV and GC-FID

    Carvalho, Myller S.; Pinho, David M.M.; Suarez, Paulo A.Z., E-mail: psuarez@unb.br [Laboratorio de Materiais e Combustiveis, Instituto de Quimica, Universidade de Brasilia, DF (Brazil); Mendonca, Marcio A. [Faculdade de Agronomia e Medicina Veterinaria, Universidade de Brasilia, DF (Brazil); Resck, Ines S. [Laboratorio de Ressonancia Magnetica Nuclear, Universidade de Brasilia, DF (Brazil)

    2012-04-15

    An analytical method using high performance liquid chromatography with UV detection (HPLC-UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 deg C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4 (v/v) (PrHex): 100% of MeOH in 0 min, 50% of MeOH and 50% of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD < 3%), linearity (r{sup 2} > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples. (author)

  11. Study on the spray characteristics of methyl esters from waste cooking oil at elevated temperature

    Lin, Yung-Sung [Department of Mechanical and Automation Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591 (China); Department of Mechanical Engineering, Hsiuping Institute of Technology, No.11, Gongye Rd., Dali City, Taichung County 412-80 (China); Lin, Hai-Ping [Department of Mechanical and Automation Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591 (China)

    2010-09-15

    In Taiwan, millions of tons of waste cooking oil are produced each year, and less than 20% of it, about 150,000 ton/a, is reclaimed and reused. Most waste oil is flushed down the drain. Utilizing waste cooking oil to make biodiesel not only reduces engine exhaust gas pollution, but also replaces food-derived fuels, and reduces ecologic river pollution. This study employed two-stage transesterification to lower the high viscosity of waste oil, utilized emulsion to reduce the methyl ester NOx pollution, and used methanol to enhance the stability and viscosity of emulsified fuel. To further analyze spray characteristics of fuels, this experiment built a constant volume bomb under high temperature, used high speed photography to analyze spray tip penetration, spray angle, and the Sauter mean diameter (SMD) of fuel droplets, and compared the results with fossil diesel. The experimental results suggested that, two-stage transesterification can significantly lower waste oil viscosity to that which is close to fossil diesel viscosity. At a temperature above 300 C, waste cooking oil methyl esters had a water content of 20%, spray droplet characteristics were significantly improved, and NOx emission dropped significantly. The optimal fuel ratio suggested in this experiment was waste cooking oil methyl ester 74.5%, methanol 5%, water 20%, and composite surfactant Span-Tween 0.5%. (author)

  12. In vivo transfer of cholesteryl ester from high and low density plasma lipoproteins into human aortic tissue

    For the study of cholesteryl ester transfer from different plasma lipoproteins into human aortic tissue, patients scheduled for reconstructive aortic surgery were intravenously injected with autologous in vitro labeled lipoproteins 20 to 24 hours before aortic intima-media samples were obtained during the operation. The injectate contained high density lipoproteins (d greater than 1.063) labeled with 3H-cholesteryl ester and lipoproteins of lower density (d less than 1.063) labeled with 14C-cholesteryl ester or lipoproteins with the opposite labeling. In 16 aortic tissue samples (some with visible atherosclerosis) from 11 normocholesterolemic patients, the aortic influx of total cholesteryl ester was 1 to 50 nmol x cm-2 x day-1. Some 39% +/- 3% (mean +/- SEM) of the influx was derived from high density lipoproteins, which in plasma accounted for only 22% +/- 2% (mean +/- SEM) of the esterified cholesterol. The findings suggest that: 1) esterified cholesterol from the two lipoprotein fractions in plasma enter the aortic intima by the same mechanism, and 2) influx of cholesteryl ester from the smaller, high density lipoproteins is greater than influx from the larger, lower density lipoproteins considering their concentrations in plasma. In some patients, the cholesterol content in the intima-media tissue with no visible atherosclerosis corresponded to only a few months of continuous cholesteryl ester influx. This time is short considering the age of the patients and, therefore, indicates that removal of esterified cholesterol from the intima-media is of major importance in preventing cholesterol deposition in the arterial wall

  13. The plasma physics measurement unit ESTER

    The ESTER measurement station on board of the landing unit of the Phobos spacecraft has three distinct units for cosmic radiation measurements on the Martian moon Phobos. They are the LET, SLED and HARP. The Low Energy Telescope (LET) has been designed to measure solar cosmic radiation (flux, energy spectra, angular distribution and ion composition) in the interplanetary space. The Solar Low-Energy Detectors (SLED) are used to detect interplanetary flux of the low-energy cosmic rays, and the galactic background radiation. The Hyperbolic Analyzer in Retarding Potential (HARP) module is used for the studies of energy and directional distributions of very low energy ions and electrons. The DPU, a unit for control and data processing of the three plasma physics measurement units is also described. (R.P.) 3 refs.; 2 figs

  14. Spasmolytic Activity of Chiral Monoterpene Esters

    Damião P. de Sousa

    2011-01-01

    Full Text Available The present study aimed to investigate the correlation between structure and spasmolytic activity of racemate and enantiomers of linalyl and citronellyl acetates, chemical constituents of several bioactive essential oils, such as Thymus leptophyllus essential oil, which contains linalyl acetate as major constituent. The monoterpene esters showed significant spasmolytic activity in guinea-pig isolated ileum. Therefore, these result confirm that linalyl acetate should be involved at spasmolytic activity of the Thymus leptophyllus essential oil. The (+-, (--, and (±-linalyl acetates exhibited a relaxant effect equipotent. (+- and (--Citronellyl acetates also showed a similar effect, however, synergistic action was presented on constituents of citronellyl acetate racemate. The study showed that the racemate and enantiomers of linalyl and citronellyl acetates are bioactives and that the position of the functional group on the molecule structures influences the effect of relaxation of the ileum.

  15. Sintesis Surfaktan Metil Ester Sulfonat dari Sulfonasi Metil Ester Asam Lemak Minyak Kastor (Ricinus communis L)

    Aritonang, Rianti E J

    2011-01-01

    Methyl ester sulfonate (MES) surfactant is an anionic surfactant which could be synthesized from oil. Surfactant have a capability to reduce surface tension, interface tension and elevate the stability of emulsion system. The material sources to produce surfactant was derived from petroleum oil, vegetables oil and animals fats. One of vegetables oil is polar castor oil, because it contained of ricinoleic acid as the major compound which has –OH group. Castor oil could be synthesize became ...

  16. Fuel properties of biodiesel from vegetable oils and oil mixtures. Influence of methyl esters distribution

    In this work, the quality of biodiesel produced by basic transesterification from several vegetable oils (soybean, rapeseed, sunflower, high oleic sunflower, Cynara Cardunculus L., Brassica Carinata and Jatropha Curca) cultivated in Extremadura has been studied in detail. The influence of raw material composition on properties such as density, viscosity, cetane number, higher heating value, iodine and saponification values and cold filter plugging point has been verified. Other biodiesel properties such as acid value, water content and flash and combustion points were more dependent on characteristics of production process. Biodiesel produced by rapeseed, sunflower and high oleic sunflower oils transesterification have been biofuels with better properties according to Norm EN 14214. Finally, it has been tested that it is possible to use oils mixtures in biodiesel production in order to improve the biodiesel quality. In addition, with the same process conditions and knowing properties of biodiesel from pure oils; for biodiesel from oils mixtures, its methyl esters content, and therefore properties dependent this content can be predicted from a simple mathematical equation proposed in this work. - Highlights: • Biodiesel quality produced by basic transesterification from vegetable oils. • We examine influences of methyl esters distribution on biodiesel properties. • Biofuels from soybean, sunflower and rapeseed oils were with better properties. • Oils mixtures improve biodiesel quality to fulfill Norm EN 14214. • An equation to predict properties of biodiesel from oil mixtures is proposed

  17. Inhibition of cholesterol ester transfer protein CGS 25159 and changes in lipoproteins in hamsters.

    Kothari, H V; Poirier, K J; Lee, W H; Satoh, Y

    1997-01-01

    As a result of screening, several isoflavans were identified to be antagonists of cholesterol ester transfer protein (CETP) activity. The present study evaluates CGS 25159, a synthetic isoflavan, as a putative inhibitor of CETP activity of human and hamster plasma. Determined by [3]CE transfer from HDL to VLDL + LDL fraction or by fluorescent-CE transfer assay, CGS 25159 inhibited CETP in both human plasma bottom fraction (d = 1.21 g/ml) and in plasma from Golden Syrian Hamsters with an IC50 contention that pharmacological down regulation of CETP activity could result in favorable changes in lipoprotein profile. PMID:9051198

  18. Solvent-Free Lipase-Catalyzed Synthesis of Technical-Grade Sugar Esters and Evaluation of Their Physicochemical and Bioactive Properties

    Ran Ye

    2016-05-01

    Full Text Available Technical-grade oleic acid esters of sucrose and fructose were prepared using solvent-free biocatalysis at 65 °C, without any downstream purification applied, and their physicochemical and bioactivity-related properties were evaluated and compared to a commercially available sucrose laurate emulsifier. To increase the conversion of sucrose and fructose oleate, prepared previously using solvent-free lipase-catalyzed esterification catalyzed by Rhizomucor miehei lipase (81% and 83% ester, respectively, the enzymatic reaction conditions was continued using CaSO4 to control the reactor’s air headspace and a lipase (from Candida antarctica B with a hydrophobic immobilization matrix to provide an ultralow water activity, and high-pressure homogenation, to form metastable suspensions of 2.0–3.3 micron sized saccharide particles in liquid-phase reaction media. These measures led to increased ester content of 89% and 96% for reactions involving sucrose and fructose, respectively. The monoester content among the esters decreased from 90% to <70% due to differences in regioselectivity between the lipases. The resultant technical-grade sucrose and fructose lowered the surface tension to <30 mN/m, and possessed excellent emulsification capability and stability over 36 h using hexadecane and dodecane as oils, comparable to that of sucrose laurate and Tween® 80. The technical-grade sugar esters, particularly fructose oleate, more effectively inhibited gram-positive foodborne pathogens (Lactobacillus plantarum, Pediococcus pentosaceus and Bacillus subtilis. Furthermore, all three sugar esters displayed antitumor activity, particularly the two sucrose esters. This study demonstrates the importance of controlling the biocatalysts’ water activity to achieve high conversion, the impact of a lipase’s regioselectivity in dictating product distribution, and the use of solvent-free biocatalysis to important biobased surfactants useful in foods, cosmetics

  19. Role of HDL in cholesteryl ester metabolism of lipopolysaccharide-activated P388D1 macrophages[S

    Uda, Sabrina; Spolitu, Stefano; Angius, Fabrizio; Collu, Maria; Accossu, Simonetta; Banni, Sebastiano; Murru, Elisabetta; Sanna, Francesca; Batetta, Barbara

    2013-01-01

    Infections share with atherosclerosis similar lipid alterations, with accumulation of cholesteryl esters (CEs) in activated macrophages and concomitant decrease of cholesterol-HDL (C-HDL). Yet the precise role of HDL during microbial infection has not been fully elucidated. Activation of P388D1 by lipopolysaccharide (LPS) triggered an increase of CEs and neutral lipid contents, along with a remarkable enhancement in 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate-HDL uptake...

  20. Formation of Plant Sterol Oxidation Products in Foods during Baking and Cooking Using Margarine without and with Added Plant Sterol Esters

    Y. Lin; D. Knol; M. Menéndez-Carreño; W.A.M. Blom; J. Matthee; H.G. Janssen; E.A. Trautwein

    2016-01-01

    Plant sterols (PS) in foods are subject to thermal oxidation to form PS oxidation products (POP). This study measured POP contents of 19 foods prepared by typical household baking and cooking methods using margarines without (control) and with 7.5% added PS (as 12.5% PS-esters, PS-margarine). Median

  1. Effects of phorbol esters in carp (Cyprinus carpio L).

    Becker, K; Makkar, H P

    1998-04-01

    Carp (Cyprinus carpio L) were fed diets containing phorbol esters at concentrations of 0, 3.75, 7.5, 15, 31, 62.5, 125, 250, 500 and 1,000 micrograms/g feed. Phorbol esters were from Jatropha curcas nuts. Jatropha curcas toxicity has been reported in humans, rodents and livestock, and phorbol esters have been identified as the main toxic agent. The adverse effects observed in carp at phorbol esters concentrations of 31 micrograms/g or higher were lower average metabolic growth rate, fecal mucus production and rejection of feed. Average metabolic growth rates (g/kg 0.8/d) in a 7-d experimental period during which diets containing phorbol esters were fed to carp (values with different letters being significantly different) were 15.4a, 14.4a, 12.5ab, 12.4ab, 10.9b, 3.4c, 0.2c, -3.8d, -4.9d and -5.6d, respectively, at the above mentioned concentrations. The values for the recovery phase of 9-d during which phorbol esters were not included in the diet were 16.0a, 15.6a, 14.9a, 15.6a, 5.3b, 1.6b, 4.6bc, 6.3bc, 7.8c and 8.2c, respectively. The adverse effects of phorbol esters were reversible since withdrawal of the esters from the diets led to gain in body mass. None of the fish died at any of the concentrations studied. Incorporation of vitamin C, an antioxidant, at levels of 0.4 and 2% in the feed did not prevent occurrence of the adverse effects of the phorbol esters. The threshold level at which phorbol esters appeared to cause adverse effects in carp was 15 micrograms/g feed or 15 ppm in the diet. Carp were highly sensitive to phorbol esters, thus making them a useful species for bioassay of these compounds. This bioassay together with other analytic procedures could be of immense use in the development of detoxification processes for agro-industrial products containing phorbol esters, such as jatropha meal or jatropha oil, and as a quality control method to monitor successive stages in industrial detoxification processes. PMID:9554059

  2. Distillative self-sorting of dynamic ester libraries.

    Ji, Qing; Miljanić, Ognjen Š

    2013-12-20

    Metal alkoxides, such as NaOt-Bu or Ti(OBu)4, can initiate acyl exchange within complex ester libraries. Reactive distillation of such dynamic combinatorial libraries (DCLs) isolates the most volatile ester at the expense of the less volatile library members that share a constituent with it. This process can be iteratively repeated to yield up to four industrially relevant esters as pure products from a single reaction setup. An algorithm has been developed to predict reactive distillation products in DCLs of as many as 121 members. PMID:24245808

  3. Synthesis and Characterization of Fatty Acid Methyl Ester by In-Situ Transesterification in Capparis Deciduas Seed

    Prasad E FUNDE

    2008-12-01

    Full Text Available (FAME Fatty acid methyl ester is made virgin or used vegetable oils (both edible and non-edible and animal fats. Fatty acid methyl ester operates in compression ignition engines like petro-diesel. Fatty acid methyl ester can be blended in any ratio with petroleum diesel fuels. It can be stored just like the petroleum diesel fuel. Petrodiesel can be replaced by biodiesel due to its superiority. It has various advantages. The seeds of Capparis deciduas are found to contain non-edible oil in the range of about 63.75 %. The percentage of biodiesel yield increases with concentration of KOH as a catalyst. The aim of this article is to demonstrate the cost effective new source of energy by single step reaction i.e. production of oil by combining extraction and reaction of extract with the mixture of alcohols. In this article the effect of catalyst concentration, time, water content and temperature on in-situ transesterification is studied to obtain optimum yield and Fatty acid methyl ester (Biodiesel Fuel characterization tests show the striking similarity of various physical & chemical properties and campers to ASTM standards.

  4. Evaluation of iodination on the ethyl ester of poppy seed oil fatty acid by N.A.A. method

    Evaluation of iodination on the ethyl ester of poppy seed oil fatty acid by N.A.A. method. Poppy seed oil has been known for having unsaturated bonds. Therefore, the addition of iodine is expected to give a poly-iodoorganic compound which can be used for roentgenography diagnosis. However, since the oil has a high viscosity which is not suitable for the mentioned purpose, it must be changed into its simple ester prior to the iodination. It was observed that there was no significant change in the double bonds of the alkyl chain, and the reaction yield was also satisfactory. A preliminary experiment showed that direct iodination using I2 on the ethyl ester did not proceed well. Therefore, a iodobromination of the ethyl ester was carried out followed by exchange reaction with I2 in chloroform. The evaluation using N.A.A. method appeared to show that exchange reaction between Br in the iodobrominated compound and I in the I2 could proceed well. However, determination of the iodine content did not agree with that of the bromine. It might be caused by the instability of the compounds. It was also observed that I2 liberated from the compounds diffused and penetrated the polyethylene material used for sample purse in the neutron activation. (author). 4 figs.; 16 refs

  5. Stereoselective formation of trisubstituted vinyl boronate esters by the acid-mediated elimination of α-hydroxyboronate esters.

    Guan, Weiye; Michael, Alicia K; McIntosh, Melissa L; Koren-Selfridge, Liza; Scott, John P; Clark, Timothy B

    2014-08-01

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

  6. Coriander seed oil methyl esters as biodiesel fuel: Unique fatty acid composition and excellent oxidative stability

    Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt%) acid. Most of the remaining fatty acid profile consisted of common 18 carbon constituents such as linoleic (9Z,12Z-octadeca-dienoic; 13.0 wt%), oleic (9Z-octadecenoic; 7.6 wt%) and stearic (octadecanoic; 3.1 wt%) acids. A standard transesterification procedure with methanol and sodium methoxide catalyst was used to provide C. sativum oil methyl esters (CSME). Acid-catalyzed pretreatment was necessary beforehand to reduce the acid value of the oil from 2.66 to 0.47 mg g-1. The derived cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of CSME was 53.3, 4.21 mm2 s-1 (40 oC), and 14.6 h (110 oC). The cold filter plugging and pour points were -15 oC and -19 oC, respectively. Other properties such as acid value, free and total glycerol content, iodine value, as well as sulfur and phosphorous contents were acceptable according to the biodiesel standards ASTM D6751 and EN 14214. Also reported are lubricity, heat of combustion, and Gardner color, along with a comparison of CSME to soybean oil methyl esters (SME). CSME exhibited higher oxidative stability, superior low temperature properties, and lower iodine value than SME. In summary, CSME has excellent fuel properties as a result of its unique fatty acid composition.

  7. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-03-15

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  8. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    U. Akhmedov

    2012-09-01

    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.

  9. Alternating Poly(ester-anhydride) by Insertion Polycondensation.

    Haim-Zada, Moran; Basu, Arijit; Hagigit, Tal; Schlinger, Ron; Grishko, Michael; Kraminsky, Alexander; Hanuka, Ezra; Domb, Abraham J

    2016-06-13

    We report on a synthetic method where polyanhydride is used as starting material and the ester monomers are inserted through complete esterification, leading to an alternating ester-anhydride copolymer. The molar ratio of ricinoleic acid (RA) and sebacic acid (SA) was optimized until polysebacic acid is completely converted to carboxylic acid-terminated RA-SA and RA-SA-RA ester-dicarboxylic acids. These dimers and trimers were activated with acetic anhydride, polymerized under heat and vacuum to yield alternating RA-SA copolymer. The resulting alternating poly(ester-anhydride) have the RA at regular intervals. The regular occurrences of RA side chains prevent anhydride interchange, enhancing hydrolytic stability, which allows storage of the polymer at room temperature. PMID:27198864

  10. Syntheses of glucomannan esters and their thermal and mechanical properties.

    Enomoto-Rogers, Yukiko; Ohmomo, Yusuke; Takemura, Akio; Iwata, Tadahisa

    2014-01-30

    Fully substituted glucomannan (GM) acylates with acyl carbon numbers (n) of 2, 3, 4, 5, 6, 8, 10, and 12 were prepared from konjac GM (KGM) in carboxylic acid/trifluoroacetic anhydride (TFAA). GM acetate acylates (n=3, 4, 5, 8, 12, 16, and 18) were prepared from KGM in acetic acid/carboxylic acid/TFAA. Differential scanning calorimetry (DSC) and X-ray diffraction revealed that the GM esters did not exhibit melting peaks and reflections derived from crystal, indicating they were amorphous. The glass-transition temperatures (Tgs) of the GM esters tended to decrease with increasing acyl carbon number, ranging from 174°C for GM acetate (GMAc) to 64°C for GM laurate (GMLa). Colorless and transparent GM ester films were obtained by solvent casting and thermo-pressing. The mechanical properties of the GM ester films were controlled by the acyl group structure. PMID:24299815

  11. Decarbonylative organoboron cross-coupling of esters by nickel catalysis.

    Muto, Kei; Yamaguchi, Junichiro; Musaev, Djamaladdin G; Itami, Kenichiro

    2015-01-01

    The Suzuki-Miyaura cross-coupling is a metal-catalysed reaction in which boron-based nucleophiles and halide-based electrophiles are reacted to form a single molecule. This is one of the most reliable tools in synthetic chemistry, and is extensively used in the synthesis of pharmaceuticals, agrochemicals and organic materials. Herein, we report a significant advance in the choice of electrophilic coupling partner in this reaction. With a user-friendly and inexpensive nickel catalyst, a range of phenyl esters of aromatic, heteroaromatic and aliphatic carboxylic acids react with boronic acids in a decarbonylative manner. Overall, phenyl ester moieties function as leaving groups. Theoretical calculations uncovered key mechanistic features of this unusual decarbonylative coupling. Since extraordinary numbers of ester-containing molecules are available both commercially and synthetically, this new 'ester' cross-coupling should find significant use in synthetic chemistry as an alternative to the standard halide-based Suzuki-Miyaura coupling. PMID:26118733

  12. Methods of refining and producing isomerized fatty acid esters and fatty acids from natural oil feedstocks

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.; Beltran, Leslie V.; Kunz, Linda A.; Pals, Tessa M.; Quinn, Jordan R; Behrends, Jr., Raymond T.; Bernhardt, Randal J.

    2016-07-05

    Methods are provided for refining natural oil feedstocks and producing isomerized esters and acids. The methods comprise providing a C4-C18 unsaturated fatty ester or acid, and isomerizing the fatty acid ester or acid in the presence of heat or an isomerization catalyst to form an isomerized fatty ester or acid. In some embodiments, the methods comprise forming a dibasic ester or dibasic acid prior to the isomerizing step. In certain embodiments, the methods further comprise hydrolyzing the dibasic ester to form a dibasic acid. In certain embodiments, the olefin is formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having unsaturated esters.

  13. RAFT Polymerization of Vinyl Esters: Synthesis and Applications

    Simon Harrisson; Xuan Liu; Jean-Noël Ollagnier; Olivier Coutelier; Jean-Daniel Marty; Mathias Destarac

    2014-01-01

    This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT) polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester) building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of th...

  14. A newly discovered xenobiotic metabolic pathway: Ethyl ester formation

    Chou, R.C.; Wyss, R.; Huselton, C.A.; Wiegand, U.W. (F. Hoffmann-La Roche Ltd., Basel (Switzerland))

    1991-01-01

    Formation of etretinate, ethyl ester of acitretin, can be confirmed in vitro and in vivo using acitretin as the substrate. Etretinate was identified by LC/MS. The in vitro incubation was performed using rat and human liver 12000 g supernatant, and the in vivo experiment was conducted in rats after oral dosing of acitretin. The ethyl ester formation was greatly enhanced by addition of or dosing with ethanol.

  15. Rheology of silicon carbide/vinyl ester nanocomposites

    Yong, Virginia; Hahn, H. Thomas

    2006-01-01

    Silicon carbide (SiC) nanoparticles with no surface treatment raise the viscosity of a vinyl ester resin much more intensely than micrometer-size SiC particles. An effective dispersant generally causes a reduction in the resin viscosity attributed to its surface-active properties and thereby increases the maximum fraction of particles that can be introduced. This article assesses the rheological behavior of SiC-nanoparticle-filled vinyl ester resin systems with the Bingham, power-law, Hersche...

  16. The enantioselective b-keto ester reductions by Saccharomyces cerevisiae

    HASSAN TAJIK

    2006-09-01

    Full Text Available The enantioselective yeast reduction of aromatic b-keto esters, by use of potassium dihydrogen phosphate, calcium phosphate (monobasic, magnesium sulfate and ammonium tartrate (diammonium salt (10:1:1:50 in water at pH 7 as a buffer for 72–120 h with 45–90 % conversion to the corresponding aromatic -hydroxy esters was achieved by means of Saccharomyces cerevisiae.

  17. Transport of glutathione diethyl ester into human cells.

    Levy, E J; Anderson, M E; Meister, A.

    1993-01-01

    Glutathione monoesters in which the carboxyl group of the glycine residue is esterified were previously found, in contrast to glutathione itself, to be effectively transported into various types of cells and to be converted intracellularly into glutathione. Glutathione monoesters are thus useful for prevention of oxidative stress, certain toxicities, and for treatment of glutathione deficiency. Glutathione diethyl ester is rapidly split to the glutathione monoethyl ester by mouse plasma gluta...

  18. Mechanism of plasma cholesteryl ester transfer in hypertriglyceridemia.

    Mann, C J; Yen, F T; Grant, A M; Bihain, B E

    1991-01-01

    Plasma net cholesteryl ester (CE) transfer and optimum cholesteryl ester transfer protein (CETP) activity were determined in primary hypertriglyceridemic (n = 11) and normolipidemic (n = 15) individuals. The hypertriglyceridemic group demonstrated threefold greater net CE transfer leading to enhanced accumulation of CE in VLDL. This increased net transfer was not accompanied by a change in CETP activity. In normolipidemia, but not in hypertriglyceridemia, net CE transfer correlated with VLDL ...

  19. Bis(2-phenylbiguanidium) adipate tetrahydrate

    Matulková, Irena; Císařová, I.; Němec, A.

    2011-01-01

    Roč. 67, JAN 2011 (2011), O118-U2378. ISSN 1600-5368 Institutional research plan: CEZ:AV0Z40400503 Keywords : biguanide derivatives * hypoglycemic agents * complexes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.347, year: 2011

  20. Solid state crystallisation of oligosaccharide ester derivatives

    Wright, E A

    2002-01-01

    An investigation of the solid state properties of oligosaccharide ester derivatives (OEDs) with potential applications in drug delivery has been carried out. The amorphous form of two OEDs, trehalose octa-acetate (TOAC) and 6:6'-di-(beta-tetraacetyl glucuronyl)-hexaacetyl trehalose (TR153), was investigated as a matrix for the sustained release of active ingredients. The matrices showed a tendency to crystallise and so polymorph screens were performed to provide crystalline samples for structural analysis. The crystal structures of TOAC methanolate and TR153 acetonitrile solvate have been determined by single-crystal laboratory X-ray diffraction. TOAC methanolate crystallises in the orthorhombic space group P2 sub 1 2 sub 1 2 sub 1 with a = 15.429(18) A, b = 17.934(19) A and c = 13.518(4) A at 123 K. The structure is isomorphous with the previously reported structure of TOAC monohydrate form II. TR153 acetonitrile solvate crystallises in the monoclinic spacegroup C2 with a = 30:160(6) A, b = 11.878(3) A, c 20...

  1. Combustion characteristics of the mustard methyl esters

    Mustard Methyl Esters (further bio diesel) and regular diesel fuel were tested in direct injection diesel engine. Analysis of experimental data was supported by an analysis of fuel injection and combustion characteristics. Engine fuelled with bio diesel had increased brake specific fuel consumption, reduced nitrogen oxides emission and smoke opacity, moderate increase in carbon monoxide emission with essentially unchanged unburned hydrocarbons emission. Increase in fuel consumption was attributed to lesser heating value of bio diesel and partially to decreased fuel conversion efficiency. Analysis of combustion characteristics revealed earlier start of injection and shorter ignition delay period of bio diesel. Resulting decrease in maximum rate of heat release and cylinder pressure was the most probable reason for reduced emission of nitrogen oxides. Analysis of combustion characteristics also showed that cetane index determined by ASTM Method D976 is not a proper measure of ignition quality of bio diesel. Conclusion was made on applicability of mustard oil as a source for commercial production of bio diesel in Pakistan. Potentialities of on improving combustion and emissions characteristics of diesel engine by reformulating bio diesel were discussed. (author)

  2. How Well Does BODIPY-Cholesteryl Ester Mimic Unlabeled Cholesteryl Esters in High Density Lipoprotein Particles?

    Karilainen, Topi; Vuorela, Timo; Vattulainen, Ilpo

    2015-01-01

    the partitioning of CE between HDL and the water phase. However, BODIPY-CE was observed to diffuse more slowly and locate itself closer to the HDL-water interface than CE due to the BODIPY probe that is constrained to the surface region, and because the CE body in BODIPY-CE prefers to align itself......We compare the behavior of unlabeled and BODIPY-labeled cholesteryl ester (CE) in high density lipoprotein by atomistic molecular dynamics simulations. We find through replica exchange umbrella sampling and unbiased molecular dynamics simulations that BODIPY labeling has no significant effect on...

  3. Determination of Mass Spectrometric Sensitivity of Different Metalloporphyrin Esters Relative to Porphyrin Ester

    Larsen, Elfinn; Egsgaard, Helge; Møller, J.; With, T. K.

    1977-01-01

    Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal compl...... complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro...

  4. Strategies for the analysis of highly reactive pinacolboronate esters.

    Zhong, Qiqing; Ngim, Kenley K; Sun, Megan; Li, Jane; Deese, Alan; Chetwyn, Nik P

    2012-03-16

    Pinacolboronate esters (or boronic acid, pinacol esters) are widely used in the Suzuki coupling reaction to connect organic building blocks for the total synthesis of complex molecules. The 2-aminopyrimidine-5-pinacolboronate ester was used as a starting material in the synthesis of a development compound, necessitating a chromatographic purity method to assess its quality. This aryl pinacolboronate ester posed unique analytical challenges due to its facile hydrolysis to the corresponding boronic acid, which is nonvolatile and poorly soluble in organic solvents. This made GC and normal-phase HPLC analysis unsuitable. In reversed-phase mode, typical sample preparation and analysis conditions promoted rapid sample degradation to the boronic acid. To overcome these challenges, unconventional approaches were necessary in order to stabilize 2-aminopyrimidine-5-pinacolboronate ester, adequately solubilize its boronic acid, and produce acceptable separation and retention. The final method employed non-aqueous and aprotic diluent, and a reversed-phase separation using highly basic mobile phases (pH 12.4) with an ion pairing reagent. These strategies were successfully applied to several other reactive pinacolboronate esters for purity analysis, demonstrating broad applicability to this unique class of compounds. PMID:22321949

  5. 工业级己二酸无机杂质元素的光谱研究%Study on Determination of Inorganic Impurity Elements in Industrial Grade Adipic Acid by Inductively Coupled Plasma Optical Emission Spectrometry

    马宁; 谢华林; 欧竞; 符靓

    2014-01-01

    An analytical method for determination of Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Cu, Zn and Pb in industrial grade adipic acid by using inductively coupled plasma optical emission spectrometry (ICP-OES) was established. The adipic acid was dissolved with HNO3, then the above 12 inorganic impurity elements in the solution were analyzed directly by ICP-OES. The working parameters of the instrument were optimized. Appropriate analysis line of various elements was selected. Y as internal standard element was used to compensate matrix effect and signal drift. Under the optimal conditions, the detection limits was 0.56~18.20µg/L, the recoveries of standard addition was in the range of 92.96%~107.90%and the RSD was 0.8%~3.3%. This method was simple, sensitive and precise, and was suitable for the determination of inorganic impurity elements in industrial grade adipic acid.%建立工业级己二酸中多个无机杂质元素的快速光谱分析方法。己二酸样品经硝酸溶解后直接用电感耦合等离子体发射光谱(ICP-OES)法测定其中的Na、Mg、Al、K、Ca、V、Cr、Mn、Fe、Cu、Zn、Pb等12种无机杂质元素。通过优化仪器工作参数,选择最佳的分析波长,并以Y为内标元素消除了测定过程中的光谱干扰和基体效应。在优化的实验条件下,方法的检出限为0.56~18.20µg·L-1,各元素的加标回收率为92.96%~107.90%,RSD为0.8%~3.3%。方法可实现工业级己二酸中无机杂质元素的快速准确测定。

  6. Synthesis of poly(ester-carbonate) with a pendant acetylcholine analog for promoting neurite growth.

    Xing, Dongming; Ma, Lie; Gao, Changyou

    2014-10-01

    The modification of biodegradable polyesters with bioactive molecules has become an important strategy for controlling neuron adhesion and neurite outgrowth in nerve regeneration. In this study we report a biodegradable poly(ester-carbonate) with a pendant acetylcholine analog, which a neurotransmitter for the enhancement of neuron adhesion and outgrowth. The acetylcholine-functionalized poly(ester-carbonate) (Ach-P(LA-ClTMC)) was prepared by copolymerizing l-lactide (LA) and 5-methyl-5-chloroethoxycarbonyl trimethylene carbonate (ClTMC), followed by quaternization with trimethylamine. The acetylcholine analog content could be modulated by changing the molar feeding fraction of ClTMC. The incorporation of the acetylcholine analog improved the hydrophilicity of the films, but the acetylcholine analog content did not significantly influence the surface morphology of the acetylcholine-functionalized films. The results of PC12 cell culture showed that the acetylcholine analog promoted cell viability and neurite outgrowth in a concentration-dependent manner. The longest length of neurite and the percentage of cells bearing neurites were obtained on the Ach-P(LA-ClTMC)-10 film. All the results indicate that the integration of the acetylcholine analog at an appropriate fraction could be an effective strategy for optimizing the existing biodegradable polyesters for nerve regeneration applications. PMID:24998182

  7. Ester Tuiksoo võitleb viina puhtuse eest / Ester Tuiksoo ; interv. Silja Lättemäe

    Tuiksoo, Ester, 1965-

    2006-01-01

    Põllumajandusminister Ester Tuiksoo lubab Euroopa Liidu piiritusjookide määruse eelnõu arutusel kaitsta seisukohta, et viinaks tuleb pidada üksnes teraviljast või kartulist valmistatud piiritusjooki

  8. Content Marketing

    Le, Duc

    2013-01-01

    The purpose of this thesis was to introduce the new trend in today’s marketing world: content marketing. It has been employed by many companies and organizations in the world and has been proven success even when it is still a fairly new topic. Five carefully selected theories of content marketing proposed by experts in the field has been collected, compared and displayed as originally and scientifically as possible in this thesis. The chosen theories provide a diversified perspectives of...

  9. Lubricating and Waxy Esters. VI. Effect of Symmetry about Ester on Crystallization of Linear Monoester Isomers

    Laziz Bouzidi

    2014-08-01

    Full Text Available The crystal structure development of jojoba-like esters incorporating either 1-decenoic acid and/or 1-decenol, namely octadec-9-enyl dec-9-enoate (JLE-281, and its isomer dec-9-enyl oleate (JLE-282 was investigated to reveal the effect of symmetry about the ester group on crystallization of aliphatic fatty monoesters. The phase transformation path was investigated with temperature-time resolved X-ray diffraction during stepped isothermal crystallization, and while cooling from the melt at a fixed rate. Startling differences in phase behavior were uncovered between the isomers. When stepped isothermals were used, selective extinctions occurred at a transition temperature for JLE-281 but not for JLE-282. The extinctions, which are due to dramatic changes in the electronic density of certain families of planes, indicate a phase transition attributed to a brusque rearrangement of the oxygen atoms in the crystal subcell. The phase transition did not occur when the JLEs were cooled continuously. The crucial role played by the position of the alkyl chain and its orientation relative to the easy rotation site of the C–O bond in the phase trajectories of the JLEs was particularly highlighted.

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

    Hohl, G.H. [Military Technology Agency, Vienna (Austria)

    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.

  11. Studies on novel interpenetrating networks of urethane modified poly(ester-amide and vinyl ester of bisphenol-C

    Pragnesh N. Dave

    2016-05-01

    Full Text Available Bisphthalamic acids were prepared by reaction of maleic anhydride and aromatic diamines. Novel poly(ester-amides (PEAs were prepared by reaction of DGEBF with bisphthalamic acids. Acrylation of PEAs was carried out using acryloyl chloride; products are called acrylated poly(ester-amides (APEAs. Epoxy resin based unsaturated poly(ester-amide resins (UPEAs can be prepared by many methods but here these were prepared by reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interpenetrating networks of equal proportional urethane modified poly(ester-amide and acrylated poly(ester-amide and vinyl ester of biaphenol c (VE resin were prepared. Urethane modified APEAs and AUPEAs were characterized by elemental analysis, molecular weight was determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  12. Continuous production of fatty acid ethyl esters from soybean oil at supercritical conditions - doi: 10.4025/actascitechnol.v34i2.11255

    Camila da Silva

    2012-03-01

    Full Text Available This work reports the production of fatty acid ethyl esters (FAEE from the transesterification of soybean oil in supercritical ethanol in a continuous catalyst-free process using different reactor configurations. Experiments were performed in a tubular reactor in one-step reaction and experimentally simulating two reactors, one operated in series and the other a recycle reactor. The reaction products were analyzed for their content of residual triglycerides, glycerol, monoglycerides, diglycerides, ethyl esters and decomposition. Results show that the configurations studied with intermediate separation of glycerol afford higher conversions of vegetable oil to their fatty acid ethyl esters derivatives when compared to the one-step reaction, with relatively low decomposition of fatty acids (< 5.0 wt%.

  13. Chromium–tungsten–titanium mixed oxides solid catalyst for fatty acid methyl ester synthesis from palm fatty acid distillate

    Highlights: • Chromium–tungsten–titanium mixed oxides as solid catalyst. • Catalyst used for esterification of palm fatty acid distillate to methyl esters. • The maximum methyl ester content is 83%. • Catalyst has shown good activity and can be recycled for 4 times. - Abstract: Chromium–tungsten–titanium mixed oxides solid catalysts were prepared and evaluated in the esterification of palm fatty acid distillate (PFAD) to produce fatty acid methyl ester (FAME). Esterification was conducted in a batch reactor at 110–200 °C temperature ranges. The catalysts were characterized by several techniques such as BET, TEM, FTIR, TGA, XRD, EDX and SEM. The treatment conditions during catalyst preparation, effect of reaction parameters, leaching of the active species and the recycled use of the catalyst were investigated. The catalyst with formula CrWTiO2 was found to be the most active with maximum FAME content of 83% obtained at best reaction conditions of 170 °C for 3 h, 2:1 (methanol to oil molar ratio) and 2 wt.% catalyst dosage. The catalyst can be recycled for 4 times. The results revealed CrWTiO2 good potentials for use in esterification of high acid value oil

  14. Sorption of organophosphate esters by carbon nanotubes

    Yan, Wei; Yan, Li [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Duan, Jinming [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Jing, Chuanyong, E-mail: cyjing@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2014-05-01

    Graphical abstract: The interfacial interactions between the OPE molecules and CNTs. - Highlights: • Oxygen-containing groups on CNTs change the sorption property for OPEs. • Molecular configuration of OPEs has insignificant impact on their sorption. • Hydrophobic, π–π EDA and Brønsted acid–base interaction occurred between the CNTs and OPEs. - Abstract: Insights from the molecular-level mechanism of sorption of organophosphate esters (OPEs) on carbon nanotubes (CNTs) can further our understanding of the fate and transport of OPEs in the environment. The motivation for our study was to explore the sorption process of OPEs on multi-walled CNTs (MWCNTs), single-walled CNTs (SWCNTs) and their oxidized counterparts (O-MWCNTs and O-SWCNTs), and its molecular mechanism over a wide concentration range. The sorption isotherm results revealed that the hydrophobicity of OPEs dominated their affinities on a given CNT and the π–π electron donor–acceptor (EDA) interaction also played an important role in the sorption of aromatic OPEs. This π–π EDA interaction, verified with Raman and FT-IR spectroscopy, could restrict the radial vibration of SWCNTs and affect the deformation vibration γ(CH) bands of OPE molecules. The OPE surface coverage on CNTs, estimated using the nonlinear Dubinin–Ashtakhov model, indicated that the oxygen-containing functional groups on CNTs could interact with water molecules by H-bonding, resulting in a decrease in effective sorption sites. In addition, FTIR analysis also confirmed the occurrence of Brønsted acid–base interactions between OPEs and surface OH groups of SWCNTs. Our results should provide mechanistic insights into the sorption mechanism of OPE contaminants on CNTs.

  15. Influence of acids composition in the properties of poly(glycerol citrate-co-adipate); Influencia da composicao dos acidos nas propriedades do poli(glicerol citrato-co-adipato)

    Brioude, M.M.; Pereira, R.; Fiuza, R.P.; Jose, N.M., E-mail: mbrioude@gmail.co [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica

    2010-07-01

    Synthetic polymers are highly resistant to degradation, being one of the greatest responsible for environment pollution. Consequently, an increase in biodegradable polymers research and development is happening. In this work we propose the synthesis and characterization of polyesters potentially biodegradable using glycerol, citric acid (CA) and adipic acid (AD). The polyesters were prepared by adding the reactants in molar ratio between glycerol:acids (1:1,5), but changing the acids ratio. The system was heated to 150-160 deg C, under nitrogen atmosphere and magnetic stirring, without catalyst adding. The samples were characterized by TGA, DSC, FTIR, XRD e SEM. The results show that the polymers prepared are amorphous polyesters, with two thermal events in 250 deg C and 450 deg C and the surfaces presents smooth and rough regions refers to bonds between glycerol and CA or AD, respectively. (author)

  16. Teixit adipós epicàrdic i senyalització a través dels Receptors Toll like (TLR): Paper en la patofisiologia de l'aterosclerosi

    Benaiges Martinez, Consol

    2015-01-01

    El Teixit adipós epicàrdic (TAE) és un dipòsit de greix visceral inusual amb continuïtat anatòmica i funcional amb les artèries coronàries i amb el miocardi. S’ha vist que en condicions fisiològiques el TAE mostra propietats cardioprotectores però en condicions patològiques el TAE pot afectar localment a les artèries coronàries a través de la secreció de substancies proinflamatòries i pot estar implicat en la patogènesi de l'aterosclerosi. L’objectiu d’aquest estudi es determinar el paper ...

  17. Potentialities of two solventless extraction approaches--stir bar sorptive extraction and headspace solid-phase microextraction for determination of higher alcohol acetates, isoamyl esters and ethyl esters in wines.

    Perestrelo, R; Nogueira, J M F; Câmara, J S

    2009-12-15

    A stir bar sorptive extraction with liquid desorption followed by large volume injection coupled to gas chromatography-quadrupole mass spectrometry (SBSE-LD/LVI-GC-qMS) was evaluated for the simultaneous determination of higher alcohol acetates (HAA), isoamyl esters (IsoE) and ethyl esters (EE) of fatty acids. The method performance was assessed and compared with other solventless technique, the solid-phase microextraction (SPME) in headspace mode (HS). For both techniques, influential experimental parameters were optimised to provide sensitive and robust methods. The SBSE-LD/LVI methodology was previously optimised in terms of extraction time, influence of ethanol in the matrix, liquid desorption (LD) conditions and instrumental settings. Higher extraction efficiency was obtained using 60 min of extraction time, 10% ethanol content, n-pentane as desorption solvent, 15 min for the back-extraction period, 10 mL min(-1) for the solvent vent flow rate and 10 degrees C for the inlet temperature. For HS-SPME, the fibre coated with 50/30 microm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) afforded highest extraction efficiency, providing the best sensitivity for the target volatiles, particularly when the samples were extracted at 25 degrees C for 60 min under continuous stirring in the presence of sodium chloride (10% (w/v)). Both methodologies showed good linearity over the concentration range tested, with correlation coefficients higher than 0.984 for HS-SPME and 0.982 for SBES-LD approach, for all analytes. A good reproducibility was attained and low detection limits were achieved using both SBSE-LD (0.03-28.96 microg L(-1)) and HS-SPME (0.02-20.29 microg L(-1)) methodologies. The quantification limits for SBSE-LD approach ranging from 0.11 to 96.56 microg L(-)and from 0.06 to 67.63 microg L(-1) for HS-SPME. Using the HS-SPME approach an average recovery of about 70% was obtained whilst by using SBSE-LD obtained average recovery were close to 80%. The

  18. Synthesis and properties of differently charged chemiluminescent acridinium ester labels.

    Natrajan, Anand; Sharpe, David

    2013-02-14

    Chemiluminescent acridinium dimethylphenyl esters containing N-sulfopropyl groups in the acridinium ring are highly sensitive, hydrophilic labels that are used in automated immunoassays for clinical diagnostics. Light emission from these labels is triggered with alkaline peroxide in the presence of a cationic surfactant. At physiological pH, N-sulfopropyl acridinium esters exist as water adducts that are commonly referred to as pseudobases. Pseudobase formation, which results from addition of water to the zwitterionic N-sulfopropyl acridinium ring, neutralizes the positive charge on the acridinium nitrogen and imparts a net negative charge to the label due to the sulfonate moiety. As a consequence, N-sulfopropyl acridinium ester conjugates of small molecule haptens as well as large molecules such as proteins gain negative charges at neutral pH. In the current study, we describe the synthesis and properties of two new hydrophilic acridinium dimethylphenyl ester labels where the net charge in the labels was altered. In one label, the structure of the hydrophilic N-alkyl group attached to the acridinium ring was changed so that the pseudobase of the label contains no net charge. In the second acridinium ester, two additional negative charges in the form of sulfopropyl groups were added to the acridinium ring to make this label's pseudobase strongly anionic. Chemiluminescence measurements of these labels, as well as their conjugates of an antibody with a neutral pI, indicate that acridinium ester charge while having a modest effect on emission kinetics has little influence on light output. However, our results demonstrate that acridinium ester charge can affect protein pI, apparent chemiluminescence stability and non-specific binding of protein conjugates to microparticles. These results emphasize the need for careful consideration of acridinium ester charge in order to optimize reagent stability and performance in immunoassays. In the current study, we observed that

  19. Effect of temperature stress on protein methyl esters

    Protein methyl esters have been implicated in a number of physiological processes. They have measured the effect of temperature stress on the levels of protein methyl esters in the mesophilic fungus Penicillium chrysogenum (PCPS) and the thermophilic fungus P. duponti (PD). PD and PCPS were incubated with [methyl-3H]methionine. The mycelia were collected by filtration, frozen in liquid nitrogen and ground to a fine powder. The nitrogen powder was extracted with either phosphate buffer or with SDS, glycerol, phosphate, 2-mercaptoethanol. Insoluble material was removed by centrifugation. The supernatants were assayed for protein methyl esters. The released [3H]methanol was extracted into toluene:isoamyl alcohol (3:2) and quantitated by liquid scintillation. The production of volatile methanol was confirmed by use of Conway diffusion cells. Soluble proteins accounted for about one-fourth of the total protein methyl ester extracted by SDS. In PCPS, the SDS extracted proteins have about three times the level of esterification of the soluble proteins whereas in PD there is little difference between soluble and SDS extracted protein. The level of protein esterification in PD is about one-tenth that observed in PCPS. Temperature stress caused large changes in the level of protein esterification. The data suggest protein methyl esters may contribute to the adaptation to environmental stress

  20. RELEASE PAPER: CAN PHOSPHATE ESTERS BE AN ALTERNATIVE TO SILICONE?

    Dan Belosinschi,

    2012-01-01

    Full Text Available Release paper is a special paper grade with one or both sides coated with non-sticking materials. Silicone is currently the only material used to produce release paper at the industrial level. Its remarkable properties and availability ensure product quality and sustainability of the industrial production. Meanwhile, the stability of silicone polymers raises serious environmental problems in terms of paper substrate recyclability. Studies are currently under way to evaluate the ability of phosphate esters as a new class of compounds capable of developing non-adhesive surface properties. This paper presents initial attempts to coat the paper with phosphate esters and to assess phosphate ester / fibrous substrate and phosphate ester / adhesive interactions. The results show that this class of compounds exhibits non-adhesive properties and, when coated on paper under certain conditions, can lead to a non-sticking surface. Despite the fact that there is a long way to achieve ester anchoring to surface fibers and to control the peeling force from an adhesive tape, preliminary results are encouraging.

  1. Chemiluminescence from alkoxy-substituted acridinium dimethylphenyl ester labels.

    Natrajan, Anand; Sharpe, David; Wen, David

    2012-05-01

    Chemiluminescent acridinium dimethylphenyl ester labels are used in automated immunoassays for clinical diagnostics. Light emission from these labels is triggered by alkaline peroxide in the presence of the cationic surfactant cetyltrimethylammonium chloride (CTAC). The surfactant plays a critical role in the chemiluminescence process of these labels by both accelerating their emission kinetics and increasing total light output enabling high throughout and improved assay sensitivity in automated immunoassays. Despite the surfactant's crucial role in the chemiluminescent reaction, no study has investigated how structural perturbations in the acridinium ring could impact the influence of the surfactant. We describe herein the synthesis and properties of three new alkoxy-substituted, acridinium dimethylphenyl esters where the nature of the alkoxy group in the acridinium ring was varied (hydrophobic or hydrophilic). Chemiluminescence measurements of these alkoxy-substituted labels indicate that hydrophilic functional groups in the acridinium ring, in particular sulfobetaine zwitterions, disrupt surfactant-mediated compression of emission times but not enhancement of light yield. These results support the hypothesis that surfactant-mediated effects require the binding of two different reaction intermediates to surfactant aggregates and, that surfactants influence light emission from acridinium esters by two separate mechanisms. Our studies also indicate that preservation of both surfactant effects on acridinium ester chemiluminescence and low non-specific binding of the label can be achieved with a relatively hydrophobic acridinium ring coupled to a hydrophilic phenolic ester leaving group. PMID:22441905

  2. Astaxanthin, canthaxanthin and astaxanthin esters in the copepod Acartia bifilosa (Copepoda, Calanoida during ontogenetic development

    Maria £otocka

    2001-12-01

    Full Text Available The contents of astaxanthin, canthaxanthin and astaxanthin esters were studied in natural populations of the copepod Acartia bifilosa from the Pomeranian Bay and Gulf of Gdansk in the southern Baltic Sea. Samples dominated by any one of three developmental groups: (1 nauplii, (2 copepodids I-III and (3 copepodids IV-V and adults of Acartia bifilosa were analysed by means of high performance liquid chromatography (HPLC. As ontogenetic development progressed, significant changes occurred in the proportion of particular pigments in the total pigment pool of the various developmental groups. Astaxanthin and canthaxanthin occurred in all the groups, the former being clearly dominant. However, an increasing percentage of astaxanthin esters was recorded in the copepodids I-III, and even more in the copepodids IV-V and adults group. Most probably, astaxanthin is the main pigment active in copepod lipid metabolism. Carotenoid pigments in copepods very likely act as efficient free-electron quenchers and may be involved as antioxidants in rapid lipid metabolism. The exogenously feeding stages (late nauplii and copepodids transform plant carotenoids taken from food and are evidently capable of metabolising astaxanthin by esterification and further degradation. It is emphasised that, according to literature data, astaxanthin esters may have an even higher quenching ability. It is suggested that crustacean carotenoid pigments, with their electron donor-acceptor abilities, may replace oxygen in peroxidation processes connected with lipid metabolism. The consequences of such a physiological role of astaxanthin for present-day estimations of energy balances in zooplankton communities are mentioned.

  3. Solid state crystallisation of oligosaccharide ester derivatives

    Wright, Elaine Ann

    2002-07-01

    An investigation of the solid state properties of oligosaccharide ester derivatives (OEDs) with potential applications in drug delivery has been carried out. The amorphous form of two OEDs, trehalose octa-acetate (TOAC) and 6:6'-di-({beta}-tetraacetyl glucuronyl)-hexaacetyl trehalose (TR153), was investigated as a matrix for the sustained release of active ingredients. The matrices showed a tendency to crystallise and so polymorph screens were performed to provide crystalline samples for structural analysis. The crystal structures of TOAC methanolate and TR153 acetonitrile solvate have been determined by single-crystal laboratory X-ray diffraction. TOAC methanolate crystallises in the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} with a = 15.429(18) A, b = 17.934(19) A and c = 13.518(4) A at 123 K. The structure is isomorphous with the previously reported structure of TOAC monohydrate form II. TR153 acetonitrile solvate crystallises in the monoclinic spacegroup C2 with a = 30:160(6) A, b = 11.878(3) A, c 20.6645(5) A and {beta} = 115.027 (10) deg at 123 K. The crystal structures of both TOAC methanolate and TR153 acetonitrile solvate are stabilised by complex networks of intermolecular C--H...O contacts. Two model compounds were selected for dissolution studies: diltiazem hydrochloride, as a water- soluble organic salt, and ketoprofen as a poorly water-soluble organic compound. Dissolution of both compounds from amorphous TOAC and TR153 matrices was investigated. The release of both drugs was more rapid and complete from TOAC matrices than from TR153 matrices, with both matrices showing a tendency to crystallise (devitrify) during the course of the dissolution experiments. This tendency was greater for the TOAC matrix, which transformed to the extent of ca. 100% within 48 hours. The available evidence suggests that devitrification of the matrix in contact with water produces a polycrystalline, non-monolithic structure rich in microscopic cracks and pores

  4. Solid state crystallisation of oligosaccharide ester derivatives

    An investigation of the solid state properties of oligosaccharide ester derivatives (OEDs) with potential applications in drug delivery has been carried out. The amorphous form of two OEDs, trehalose octa-acetate (TOAC) and 6:6'-di-(β-tetraacetyl glucuronyl)-hexaacetyl trehalose (TR153), was investigated as a matrix for the sustained release of active ingredients. The matrices showed a tendency to crystallise and so polymorph screens were performed to provide crystalline samples for structural analysis. The crystal structures of TOAC methanolate and TR153 acetonitrile solvate have been determined by single-crystal laboratory X-ray diffraction. TOAC methanolate crystallises in the orthorhombic space group P212121 with a = 15.429(18) A, b = 17.934(19) A and c = 13.518(4) A at 123 K. The structure is isomorphous with the previously reported structure of TOAC monohydrate form II. TR153 acetonitrile solvate crystallises in the monoclinic spacegroup C2 with a = 30:160(6) A, b = 11.878(3) A, c 20.6645(5) A and β = 115.027 (10) deg at 123 K. The crystal structures of both TOAC methanolate and TR153 acetonitrile solvate are stabilised by complex networks of intermolecular C--H...O contacts. Two model compounds were selected for dissolution studies: diltiazem hydrochloride, as a water- soluble organic salt, and ketoprofen as a poorly water-soluble organic compound. Dissolution of both compounds from amorphous TOAC and TR153 matrices was investigated. The release of both drugs was more rapid and complete from TOAC matrices than from TR153 matrices, with both matrices showing a tendency to crystallise (devitrify) during the course of the dissolution experiments. This tendency was greater for the TOAC matrix, which transformed to the extent of ca. 100% within 48 hours. The available evidence suggests that devitrification of the matrix in contact with water produces a polycrystalline, non-monolithic structure rich in microscopic cracks and pores which allows diffusion of the

  5. Formulation development and optimization of palm kernel oil esters-based nanoemulsions containing sodium diclofenac

    Rezaee M

    2014-01-01

    Full Text Available Malahat Rezaee,1 Mahiran Basri,1,2 Raja Noor Zaliha Raja Abdul Rahman,3 Abu Bakar Salleh,3 Naz Chaibakhsh,4 Roghayeh Abedi Karjiban21Institute of Bioscience, 2Faculty of Science, 3Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 4Faculty of Science, University of Guilan, Rasht, IranAbstract: Response surface methodology was employed to study the effect of formulation composition variables, water content (60%–80%, w/w and oil and surfactant (O/S ratio (0.17–1.33, as well as high-shear emulsification conditions, mixing rate (300–3,000 rpm and mixing time (5–30 minutes on the properties of sodium diclofenac-loaded palm kernel oil esters-nanoemulsions. The two response variables were droplet size and viscosity. Optimization of the conditions according to the four variables was performed for preparation of the nanoemulsions with the minimum values of particle size and viscosity. The results showed that the experimental data could be sufficiently fitted into a third-order polynomial model with multiple regression coefficients (R2 of 0.938 and 0.994 for the particle size and viscosity, respectively. Water content, O/S ratio and mixing time, quadrics of all independent variables, interaction between O/S ratio and mixing rate and between mixing time and rate, as well as cubic term of water content had a significant effect (P<0.05 on the particle size of nanoemulsions. The linear effect of all independent variables, quadrics of water content and O/S ratio, interaction of water content and O/S ratio, as well as cubic term of water content and O/S ratio had significant effects (P<0.05 on the viscosity of all nanoemulsions. The optimum conditions for preparation of sodium diclofenac nanoemulsions were predicted to be: 71.36% water content; 0.69 O/S ratio; 950 rpm mixing rate, and 5 minute mixing time. The optimized formulation showed good storage stability in different temperatures

  6. Saliva-catalyzed hydrolysis of a ketobemidone ester prodrug

    Hansen, L.B.; Christrup, Lona Louring; Bundgaard, H.

    Saliva enzyme-catalysed hydrolysis of ester prodrugs or drugs containing sensitive ester groups may be a limiting factor for the buccal absorption of such compounds. Using the isopropyl carbonate ester of ketobemidone as a model substance of a hydrolysis-sensitive prodrug the esterase activity of...... human saliva has been characterized as a function of various factors. The esterase activity was found to decrease rapidly upon storage of the saliva at 37°C. The activity increased with increasing pH in the range 4.5-7.4 and with increasing salivation flow rate up to a rate of 0.9 ml min. Under resting...... conditions, the flow rate was about 0.2 ml min which implied a greatly decreased esterase activity. The activity was highest after fasting and decreased after intake of a meal. The intraindividual variation in the saliva esterase activity was small whereas a larger interindividual variation was found....

  7. Isolation and pharmacological activity of phenylpropanoid esters from Marrubium vulgare.

    Sahpaz, Sevser; Garbacki, Nancy; Tits, Monique; Bailleul, Francois

    2002-03-01

    The isolation and identification of major phenylpropanoid esters from Marrubium vulgare: (+) (E)-caffeoyl-L-malic acid 1, acteoside 2, forsythoside B 3, arenarioside 4, ballotetroside 5, as well as their anti-inflammatory activity are reported for the first time. We evaluated the inhibitory effects of these five compounds on cyclooxygenase (Cox) catalysed prostaglandin biosynthesis activity. Only the glycosidic phenylpropanoid esters showed an inhibitory activity towards the Cox-2 enzyme and three of them: acteoside 2, forsythoside B 3, arenarioside 4, exhibited higher inhibitory potencies on Cox-2 than on Cox-1. These results are of interest, as Cox-2 is mainly associated with inflammation and the Cox-1 inhibition with adverse side effects often observed with non-steroidal anti-inflammatory drugs. The occurrence of these phenylpropanoid esters could also explain some other pharmacological properties of M. vulgare. PMID:11849848

  8. Maximization of fructose esters synthesis by response surface methodology.

    Neta, Nair Sampaio; Peres, António M; Teixeira, José A; Rodrigues, Ligia R

    2011-07-01

    Enzymatic synthesis of fructose fatty acid ester was performed in organic solvent media, using a purified lipase from Candida antartica B immobilized in acrylic resin. Response surface methodology with a central composite rotatable design based on five levels was implemented to optimize three experimental operating conditions (temperature, agitation and reaction time). A statistical significant cubic model was established. Temperature and reaction time were found to be the most significant parameters. The optimum operational conditions for maximizing the synthesis of fructose esters were 57.1°C, 100 rpm and 37.8 h. The model was validated in the identified optimal conditions to check its adequacy and accuracy, and an experimental esterification percentage of 88.4% (±0.3%) was obtained. These results showed that an improvement of the enzymatic synthesis of fructose esters was obtained under the optimized conditions. PMID:21356336

  9. Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

    Noriyoshi Matsumi

    2014-11-01

    Full Text Available Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl imide (LiNTf2, the resulting 1-(2-hydroxyethyl-3-methylimidazolium NTf2 was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by 1H-, 13C-, 11B- and 19F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10−4–1.6 × 10−5 S cm−1 at 51 °C. This was higher than other organoboron molten salts ever reported.

  10. Oxidation stability of biofuel containing Camelina sativa oil methyl esters and its impact on energy and environmental indicators of diesel engine

    Highlights: ► We present the results of the engine tests when fueling with biodiesel containing Camelina sativa methyl esters. ► We examine dependence of the engine and environmental characteristics on storage of biodiesel fuel. ► Characteristics of fuel with C. sativa methyl esters after storage are presented. - Abstract: This report includes assessments of comparative studies on the physical, chemical, and motor properties of stored biofuels produced from Camelina sativa oil. The properties of biofuel containing C. sativa oil methyl esters (CMEs) were compared with the properties of fossil diesel fuel and standardized rapeseed oil methyl ester (RME) and fossil diesel fuel blends. To ensure compliance with the requirements for fatty acid methyl esters established by the EN 14214 standard, pure CMEs were blended with methyl esters of animal origin, the content of which accounted for 32% of the blend. Motor studies were carried out in the VALMET 320 DMG diesel engine while using fuel blends consisting of 30% of a mixture of C. sativa oil and pork lard methyl esters and 70% fossil diesel fuel. Environmental and energy indicators were compared with indicators related to RME and fossil diesel fuel. In the course of the experiments, it was established that when no anti-oxidant was used, the C. sativa oil and pork lard methyl ester mixtures met the requirements of the oxidation standard only during the first month of storage, whereas the physical properties did not change considerably during the whole storage period. Due to the properties of fuels containing C. sativa oil methyl esters, they can be used in cold climate areas in summertime. As a result of performing measurements of emissions of hazardous components, it was observed that throughout the storage period, the maximum reduction of CO reached 7–10%, whereas the decrease in HC was – 5–8% and that of NOx was approximately 4%. The most significant effect was detected in the case of smoke intensity

  11. Jojoba methyl ester as a diesel fuel substitute: Preparation and characterization

    Radwan, M.S.; Ismail, M.A.; Elfeky, S.M.S.; Abu-Elyazeed, O.S.M. [Mechanical Power Engineering Department, Faculty of Engineering at Mattaria, University of Helwan, Masakin Elhelmia, Mattaria, Cairo 11718 (Egypt)

    2007-02-15

    The aim of the present work is to prepare jojoba methyl ester (JME) as a diesel fuel substitute. This was carried out experimentally and its chemical and physical properties were determined. Esterification method is used to produce methyl ester from raw jojoba oil. This method is optimized to produce the highest amount of fuel using a minimum amount of methyl alcohol. To achieve the above aim, a test rig for fuel production was developed. To measure the JME burning velocity a constant volume bomb was developed. The bomb was fully instrumented with a piezoelectric pressure transducer, charge amplifier, digital storage oscilloscope, A/D converter and a personal computer. Several grades of fuel were produced but, two grades only were selected and tested as an economical alternative fuel. The chemical and physical properties of these grades of fuel are measured as well as the laminar burning velocity. It is found that JME liquid fuel exhibited lower burning velocities than iso-octane. The new fuel is found to be suitable for compression ignition engine particularly in the indirect-injection ones, while for direct-injection, and high-speed engines fuel modifications are required. The new fuel is safe, has no sulphur content and reduces the engine wear as well as lengthens the lifetime of lubricating oil. (author)

  12. Performance and emission analysis of cottonseed oil methyl ester in a diesel engine

    Aydin, Hueseyin [Department of Automotive, Faculty of Technical Education, Batman University, Batman 72060 (Turkey); Bayindir, Hasan [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Dicle University, Diyarbakir, 21280 (Turkey)

    2010-03-15

    In this study, performance and emissions of cottonseed oil methyl ester in a diesel engine was experimentally investigated. For the study, cottonseed oil methyl ester (CSOME) was added to diesel fuel, numbered D2, by volume of 5%(B5), 20%(B20), 50%(B50) and 75%(B75) as well as pure CSOME (B100). Fuels were tested in a single cylinder, direct injection, air cooled diesel engine. The effects of CSOME-diesel blends on engine performance and exhaust emissions were examined at various engine speeds and full loaded engine. The effect of B5, B20, B50, B75, B100 and D2 on the engine power, engine torque, bsfc's and exhaust gasses temperature were clarified by the performance tests. The influences of blends on CO, NO{sub x}, SO{sub 2} and smoke opacity were investigated by emission tests. The experimental results showed that the use of the lower blends (B5) slightly increases the engine torque at medium and higher speeds in compression ignition engines. However, there were no significant differences in performance values of B5, B20 and diesel fuel. Also with the increase of the biodiesel in blends, the exhaust emissions were reduced. The experimental results showed that the lower contents of CSOME in the blends can partially be substituted for the diesel fuel without any modifications in diesel engines. (author)

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

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

    2016-09-01

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

  14. Effects of Selected Polysorbate and Sucrose Ester Emulsifiers on the Physicochemical Properties of Astaxanthin Nanodispersions

    Navideh Anarjan

    2013-01-01

    Full Text Available The effects of selected nonionic emulsifiers on the physicochemical characteristics of astaxanthin nanodispersions produced by an emulsification/evaporation technique were studied. The emulsifiers used were polysorbates (Polysorbate 20, Polysorbate 40, Polysorbate 60 and Polysorbate 80 and sucrose esters of fatty acids (sucrose laurate, palmitate, stearate and oleate. The mean particle diameters of the nanodispersions ranged from 70 nm to 150 nm, depending on the emulsifier used. In the prepared nanodispersions, the astaxanthin particle diameter decreased with increasing emulsifier hydrophilicity and decreasing carbon number of the fatty acid in the emulsifier structure. Astaxanthin nanodispersions with the smallest particle diameters were produced with Polysorbate 20 and sucrose laurate among the polysorbates and the sucrose esters, respectively. We also found that the Polysorbate 80- and sucrose oleate-stabilized nanodispersions had the highest astaxanthin losses (i.e., the lowest astaxanthin contents in the final products among the nanodispersions. This work demonstrated the importance of emulsifier type in determining the physicochemical characteristics of astaxanthin nano-dispersions.

  15. Organophosphate ester flame retardants and plasticizers in human placenta in Eastern China.

    Ding, Jinjian; Xu, Zemin; Huang, Wei; Feng, Limin; Yang, Fangxing

    2016-06-01

    Organophosphate esters (OPEs) have been widely used in various products as alternatives to brominated flame retardants. Although widespread OPE exposure is expected in humans, the accumulation of OPEs has seldom been studied in the human body. In this study, 12 OPE analogs were analyzed in 50 human placentas collected in Eastern China. The concentrations of the 9 most frequently detected OPEs (Σ9OPEs) ranged from 34.4 to 862ng/g lipid weight (lw), with a median of 301ng/g lw. Tri(2-chloroethyl) phosphate (TCEP) was identified as the most abundant analog, with a median concentration of 142ng/g lw, followed by tributoxyethyl phosphate (TBEP) and triphenyl phosphate (TPhP). Statistical analysis showed no analog of OPEs or Σ9OPEs was positively correlated with the lipid content of the placentas. There were no correlations observed between the OPE concentrations and maternal characteristics. Food consumption habits exhibited weak effects on OPE levels in the placentas. Further investigation is required to determine the effects of OPEs on fetuses due to the expected increase in maternal exposure to these esters. PMID:26950635

  16. Enhanced ionic conductivity in borate ester plasticized Polyacrylonitrile electrolytes for lithium battery application

    The effect of low molecular weight borate ester on the ionic conductivity of polyacrylonitrile (PAN) was systematically investigated by means of measuring conductivity using the impedance technique. Gel polymer electrolyte (SPE) films consisting of PAN as host polymer, LiCF3SO3 and LiBF4 as ionic salts, and poly (ethylene glycol) borate ester (PEGB), ethylene carbonate/propylene carbonate (EC/PC) as plasticizers were prepared by physical blending method. All measurements were performed on electrolyte samples with various contents. Fourier transform infrared spectroscopy (FT-IR) gave evidence of the interactions among PAN, plasticizers and lithium salt. The surface morphology of the electrolytes was investigated by scanning electron microscopy (SEM). Thermal properties of these materials were searched with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Conductivity studies of these blend polymer electrolytes were carried out in the temperature range 20–100 °C. The maximum ionic conductivity values of 1.8 × 10−3 and 1.4 × 10−4 S cm−1 were measured for the film containing 4PAN-10EC/PC-4LiBF4 and 4PAN-10PEGB-4LiCF3SO3, respectively, at room temperature. These films have a good conductivity, better dimensional stability and wide electrochemical stability window. These unique properties make the composite gel membranes suitable for application as electrolyte in rechargeable Li-ion batteries

  17. Raman spectroscopic analysis of isomers of biliverdin dimethyl ester.

    Matysik, J; Hildebrandt, P; Smit, K; Mark, F; Gärtner, W; Braslavsky, S E; Schaffner, K; Schrader, B

    1997-06-01

    The constitutional isomers of biliverdin dimethyl ester, IX alpha and XIII alpha, were studied by resonance Raman spectroscopy. The far-reaching spectral similarities suggest that despite the different substitution patterns, the compositions of the normal modes are closely related. This conclusion does not hold only for the parent state (ZZZ, sss configuration) but also for the configurational isomers which were obtained upon double-bond photoisomerization. Based on a comparison of the resonance Raman spectra, a EZZ configuration is proposed for one of the two photoisomers of biliverdin dimethyl ester IX alpha, while a ZZE, ssa configuration has been assigned previously to the second isomer. PMID:9226559

  18. Sodium borohydride reduction of aromatic carboxylic acids via methyl esters

    Aamer Saeed; Zaman Ashraf

    2006-09-01

    A number of important aromatic carboxylic acids precursors, or intermediates in the syntheses of natural products, are converted into methyl esters and reduced to the corresponding primary alcohols using a sodium borohydride-THF-methanol system. The alcohols are obtained in 70-92% yields in 2-5 hours, in a pure state. This two-step procedure not only provides a better alternative to aluminum hydride reduction of acids but also allows the selective reduction of esters in presence of acids, amides, nitriles or nitro functions which are not affected under these conditions.

  19. Solvent effects on hydrogen bonding between primary alcohols and esters

    DHARMALINGAM K.; RAMACHANDRAN K.; SIVAGURUNATHAN P.

    2006-01-01

    The interaction by hydrogen bond formation of some primary alcohols (1-heptanol, 1-octanol and 1-decanol) with esters (methyl methacrylate, ethyl methacrylate and butyl methacrylate) was investigated in non-polar solvents viz., n-heptane,CCh and benzene by means of FTIR spectroscopy. Formation constants and free energy changes of complex formation were determined. The dependence of the equilibrium constants and free energy changes of complex formation on the alkyl chain length of both the alcohols and esters are discussed. The solvent effect on the hydrogen bond formation is discussed in terms of specific interaction between the solute and solvent.

  20. Pancreatic lipolytic enzymes in human duodenal contents

    The total pancreatic lipolytic capacity was determined in duodenal contents in healthy humans 10 to 120 min after a liquid test meal, by estimating the amount of pancreatic lipase, colipase, carboxyl ester lipase, and phospholipase A2 by means of radioimmunoassays and enzymatic assays. The molar concentrations of the different proteins were of the same order of magnitude. The relative specific activity amounted to 75 to 120% for lipase, 45 to 80% for colipase, 30 to 70% for carboxyl ester lipase, and 45 to 120% for phospholipase A2. These varied, and sometimes low values can be explained by the fact that the enzymes are inhibited or partly inactivated in the duodenal contents by surface denaturation, in which cases the products are still immunoreactive. Also, the proforms of colipase and phospholipase A2 may not always be completely activated. Furthermore, the specific activities of the pure enzymes are related to the methods used, which are not specific enough to distingush completely the three enzymes and the cofactor in duodenal contents. 24 refs., 4 figs., 1 tab

  1. Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

    Lawler, Katherine [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop a model based on fractal-type agglomeration. It is believed that the structure of the particle flocs in these suspensions changes with the addition of saccharides which leads to the resultant viscosity decrease. The viscosity of the BECy suspensions increased with solids content, and the viscosity increase was greater than predicted by the classical Einstein equation for dilute suspensions. Instead, the Mooney equation fits the viscosity behavior well from 0-20 vol% solids. The viscosity reduction achieved at high particle loadings by the addition of benzoic acid was also investigated by NMR. It appears that the benzoic acid interacts with the surface of the alumina particle which may

  2. IN SITU TRANSESTERIFIKASI MINYAK BIJI MAHONI MENJADI METIL ESTER DENGAN CO-SOLVENT THF (TETRAHYDROFURAN

    Elvianto Dwi Daryono

    2014-05-01

    Full Text Available Tujuan dari penelitian  adalah untuk mengkaji efektifitas penggunaan co-solvent THF pada reaksi transesterifikasi in situ minyak biji mahoni sebagai solusi proses pembuatan biodiesel yang efektif dan efisien. Variabel dan kondisi operasi  meliputi katalis NaOH, kecepatan pengadukan 450 rpm, suhu reaksi suhu kamar, rasio molar minyak:metanol = 1:101,39, rasio molar katalis:minyak = 0,5:1, % FFA minyak 1,42%, kadar air biji 0,8%, waktu reaksi 3, 8, 13, 18, dan 23 menit serta rasio molar minyak:THF 1:47,15, 1:57,85 dan 1:67,85. Biji mahoni yang telah dikeringkan dan dihaluskan ukuran +20/-30 mesh sebanyak 50 gram dimasukkan dalam labu leher tiga yang dilengkapi pendingin balik dan ditambahkan metanol, THF dan katalis NaOH serta dilakukan reaksi sesuai dengan variabel dan kondisi operasi penelitian. Setelah reaksi selesai dipisahkan antara ampas dan filtratnya. Filtrat didistilasi pada suhu ± 70oC dan residu hasil distilasi dimasukkan dalam corong pemisah dan didiamkan selama ± 12 jam agar terbentuk 2 lapisan. Lapisan atas sebagai metil ester kemudian dianalisis konsentrasi metil oleatnya dengan GC. Dari data hasil penelitian didapatkan hasil terbaik pada rasio molar minyak:THF = 1:67,85 dan waktu reaksi 23 menit dengan  konsentrasi metil oleat 59,10% dan yield metil ester 79,69%. Densitas metil ester 0,8791 g/cm3 memenuhi SNI 04-7182-2006 yaitu 0,85 – 0,89 g/cm3. Kata kunci : biodiesel, co-solvent, minyak biji mahoni, transesterifikasi in situ Abstract The purpose of this research was to assess the effectiveness of the use of co-solvent THF for in situ transesterification reaction mahogany seed oil as a biodiesel manufacturing process solutions that effectively and efficiently. Variables and operating conditions include catalyst NaOH, stirring speed of 450 rpm, room temperature the reaction temperature, molar ratio of oil: methanol = 1: 101.39, the molar ratio of catalyst: oil = 0.5: 1, % FFA oil is 1,42%,  moisture content seed of 0

  3. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, condensated... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  4. N-[11C]methylpiperidine esters as acetylcholinesterase substrates: an in vivo structure-reactivity study

    A series of simple esters incorporating the N-[11C]methylpiperidine structure were examined as in vivo substrates for acetylcholinesterase in mouse brain. 4-N-[11C]Methylpiperidinyl esters, including the acetate, propionate and isobutyrate esters, are good in vivo substrates for mammalian cholinesterases. Introduction of a methyl group at the 4-position of the 4-piperidinol esters, to form the ester of a teritary alcohol, effectively blocks enzymatic action. Methylation of 4- N-[11C]methylpiperidinyl propionate at the 3-position gives a derivative with increased in vivo reactivity toward acetylcholinesterase. Esters of piperidinecarboxylic acids (nipecotic, isonipecotic and pipecolinic acid ethyl esters) are not hydrolyzed by acetylcholinesterase in vivo, nor do they act as in vivo inhibitors of the enzyme. This study has identified simple methods to both increase and decrease the in vivo reactivity of piperidinyl esters toward acetylcholinesterase

  5. MAIN CONTENTS

    2011-01-01

    Discussion on the Modern Agriculture Management Mode and its Innovation in China Mode of agricultural management is organic unify between form of agriculture management and way of agriculture management. Changes of agricultural management form are the content of system innovation;Transformation of agricultural management way belongs to the category of technical progress. We found that, precision agriculture with the moderate scale by professional farmers is the dominant mode of agricultural management. Coexisting of multiple modes is the pattern and evolution trend of modern agriculture management mode. The precision agriculture based on household business of moderate scale mode, we needs of rural economd socialization of

  6. EXPERIMENTAL INVESTIGATION OF LINSEED AND NEEM METHYL ESTERS AS BIODIESEL ON CI ENGINE

    V.DHANA RAJU; P.RAVINDRA KUMAR

    2012-01-01

    An experimental investigations were carried out on C.I.engine with Bio Diesel blends of Linseed Methyl Esters and Neem Oil Methyl Esters .The engine used for the experiments was single cylinder Four Stroke water cooled, constant speed diesel engine . Linseed Methyl ester (LSOME) and Neem oil methyl ester (NOME) are derived through transesterification process and parameters of transesterification were optimized. The blends of various proportions of the LSOME & NOME with diesel were prepared, a...

  7. Lutein and lutein esters in whole grain flours made from 75 genotypes of 5 triticum species grown at multiple sites.

    Ziegler, Jochen U; Wahl, Sabine; Würschum, Tobias; Longin, C Friedrich H; Carle, Reinhold; Schweiggert, Ralf M

    2015-05-27

    Concentrations of lutein and lutein esters were determined in an ample collection of 75 wheat genotypes comprising bread wheat (Triticum aestivum L.), durum (Triticum durum Desf.), spelt (Triticum spelta L.), emmer (Triticum dicoccum Schrank), and einkorn (Triticum monococcum L.) grown in five different environments. Einkorn genotypes showed the highest total amounts of lutein (4.5-7.8 μg/g dry matter), followed by durum (2.0-4.6 μg/g), spelt (0.9-2.0 μg/g), emmer (0.8-1.9 μg/g), and bread wheat (0.7-2.0 μg/g). Due to the observed highly significant genetic variance and high heritability, lutein contents of wheat genotypes may be increased by future plant breeding. Detailed HPLC-DAD-APCI(±)-MS(n) data allowing the identification of six lutein monoesters and nine diesters are presented. Linoleic, palmitic, and oleic acids were the most abundant fatty acids in both the lutein esters and total free lipid fractions. Lutein esters were virtually absent in the tetraploid durum and emmer species, whereas their concentrations considerably differed among the genotypes belonging to the other species. PMID:25946219

  8. Preconcentration procedures for phthalate esters combined with chromatographic analysis.

    Lv, Xueju; Hao, Yi; Jia, Qiong

    2013-08-01

    Phthalate esters are endocrine disrupters or mutagens. They are widely used as plasticizers and can be usually found in environmental samples, such as food, soil and polluted air. However, it is difficult to directly determine phthalate esters owing to their relatively low concentration and complex matrices. Therefore, preconcentration and separation have become increasingly important. In recent years, many preconcentration methods have been successfully developed and widely used, such as liquid-liquid extraction, dispersive liquid-liquid microextraction and solid-phase extraction. These preconcentration methods for phthalate esters can be applied to various real samples, water, soil, air, food and cosmetics. The aim of this paper is to review recent literature studies (primarily from the last five years) about preconcentration techniques for phthalate esters coupled with chromatographic analysis. The following text describes several preconcentration approaches, including liquid-liquid extraction, dispersive liquid-liquid microextraction, cloud point extraction, solid-phase extraction, solid-phase microextraction and stir bar sorptive extraction. Their advantages and disadvantages are also summarized. PMID:23696389

  9. A New Jatrophane Diterpenoid Ester from Euphorbia turczaninowii

    Li Gen LIU; Ren Xiang TAN; You Ming GONG

    2006-01-01

    A new jatrophane diterpenoid ester (2S, 3S, 4R, 5R, 7S, 8R, 13R, 15R) - 3, 5, 7, 8, 15-pentaacetoxy-9, 14-dioxojatropha-6(17), 11E-diene was isolated from the whole plant of Euphorbia turczaninowii Kar. & Kir.. Its structure was characterized by spectral analysis and confirmed by X-ray crystallographic analysis.

  10. New triterpene esters from flowerheads of Arnica lonchophylla.

    Schmidt, Thomas J; von Raison, Jeanette; Willuhn, Günter

    2004-10-01

    From the flowerheads of Arnica lonchophylla Greene ssp. lonchophylla Maguire (Asteraceae), a variety of mono-, di- and trihydroxytriterpenes of the oleanane, ursane, lupane and dammarane types were isolated and their structures elucidated by EI and CI mass spectrometry and extensive NMR spectroscopic analysis. Most of the compounds are esterified at position 3 with lauric, myristic, palmitic and stearic acids. Several ester derivatives of known triterpenes represent new natural products. The triterpenetriols 20(30)-taraxasten-3beta,16beta,21alpha-triol (arnitriol A) and lupane-3beta,16beta,20-triol, both isolated in the form of their C3-fatty acid ester derivatives, possess hydroxylation patterns which have not been described previously. Besides small amounts of triterpenetriol esters, the lauric, myristic, palmitic and stearic acid esters of arnidiol, faradiol, maniladiol and calenduladiol were also identified in the flowerheads of A. montana (Arnicae flos Ph. Eur.), A. chamissonis ssp. foliosa and A. angustifolia ssp. attenuata. A search for sesquiterpene lactones in the flowers of A. lonchophylla resulted in the identification of small amounts of helenalin and 11alpha,13-dihydrohelenalin. PMID:15490326

  11. RAFT Polymerization of Vinyl Esters: Synthesis and Applications

    Simon Harrisson

    2014-05-01

    Full Text Available This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of the range, many vinyl esters have been considered in order to tune various polymer properties, in particular, solubility in supercritical carbon dioxide (scCO2. A special emphasis is given to novel poly(vinyl alkylates with enhanced solubilities in scCO2, with applications as reactive stabilizers for dispersion polymerization and macromolecular surfactants for CO2 media. Other miscellaneous uses of poly(vinyl esters synthesized by RAFT, for instance as a means to produce poly(vinyl alcohol with controlled characteristics for use in the biomedical area, are also covered.

  12. Polyfluorinated alkyl phosphate ester surfactants - current knowledge and knowledge gaps

    Taxvig, Camilla; Rosenmai, Anna Kjerstine; Vinggaard, Anne Marie

    2014-01-01

    information on fluorochemicals. Polyfluorinated alkyl phosphate ester surfactants (PAPs) belong to the group of polyfluorinated alkyl surfactants. They have been detected in indoor dust and are widely used in food-contact materials, from which they have the ability to migrate into food. Toxicological data on...

  13. Enzymatic synthesis of oligo- and polysaccharide fatty acid esters

    Broek, van den L.A.M.; Boeriu, C.G.

    2013-01-01

    Amphiphilic oligo- and polysaccharides (e.g. polysaccharide alkyl or alkyl-aryl esters) form a new class of polymers with exceptional properties. They function as polymeric surfactants, whilst maintaining most of the properties of the starting polymeric material such as emulsifying, gelling, and fil

  14. SYNTHESIS OF ACRYLIC ESTERS IN PTC: KINETICS AND ECOLOGICAL ASPECTS

    G.Torosyan

    2013-06-01

    Full Text Available The synthesis of esters of acrylic acids, which are applied for synthesis of polymeric materials by phase transfer catalysis were discussed (PTC, which is very useful for reduction of reaction consumption of materials and power.This method has substantial advantages including high speed of the process, soft condition of reaction and reduced pollution.

  15. Separation of isomeric xylenes by pervaporation through cellulose ester membranes

    Mulder, M.H.V.; Kruitz, F.; Smolders, C.A.

    1982-01-01

    The interaction between the isomeric xylenes and different cellulose esters was investigated using solubility parameter considerations and through measurements of swelling values. p]Hansen's three-dimensional solubility parameters δd, δp, δh of all the components have been calculated. These values h

  16. Radical Mechanism in the Elimination of 2-Arylsulfinyl Esters

    LaTorre, Antonio; López Martín, Irakusne; Ramírez, Victoria; Rodríguez Pastor, Santiago; Izquierdo Ferrer, Javier; González Adelantado, Florenci Vicent; Vicent Barrera, Cristian

    2012-01-01

    The mechanism of the dehydrosulfenylation of 2-arylsulfinyl esters was investigated. The reaction was found to follow a homolytic cleavage mechanism as verified by electrospray ionization tandem mass spectrometry and experimental work. Rearranged sulfoxides are obtained as byproduct during the elimination reaction.

  17. Comparative assay of antioxidant packages for dimer of estolide esters

    A series of 26 different antioxidants and commercial antioxidant packages, containing both natural and synthetic-based materials, were evaluated with dimeric coconut-oleic estolide 2-ethylhexyl ester. The different antioxidants were broken down into different classes of materials: phenolic, aminic, ...

  18. 21 CFR 172.735 - Glycerol ester of rosin.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glycerol ester of rosin. 172.735 Section 172.735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD..., gum rosin, or tall oil rosin may be safely used in food in accordance with the following...

  19. Steric effect of ortho subsituents on ester reactivity towards nucleophiles

    Reactivities of ortho- and para-substituted phenyl acetates in isotopic acyl exchange and in aminolysis were compared. In aminolysis the ortho-substituted esters reacted more rapidly than their para isomers. The increased reactivity is attributed to the proton acceptor ortho substituents. These substituents act as general base catalytic functions in aminolysis but they act differently in isotopic acyl exchange. (author)

  20. Synthesis, Characterization, Antibacterial and Antifungal Evaluation of Novel Monosaccharide Esters

    Yong Deng

    2012-07-01

    Full Text Available A novel series of 3-(2-furylacrylate monosaccharide esters Iaf and menthyloxycarbonyl monosaccharide esters IIaf were designed and synthesized. The chemical structures of the target compounds were confirmed by IR, 1H- and 13C-NMR and ESI-MS, and the target compounds were investigated for their in vitro antibacterial and antifungal activities. The antibacterial screening results showed that the 3-(2-furylacrylate monosaccharide ester derivatives Iaf were either inactive or only weakly active against the three Gram-positive bacterial strains tested, whereas the menthyloxycarbonyl monosaccharide ester derivatives IIaf exhibited higher levels of activity, with compound IIe being especially potent. The results of the antifungal screening revealed that compounds Ib, Ie, IIb and IIc displayed potent in vitro activities, whereas If and IIf showed promising activities against all of the microorganisms tested, with If exhibiting levels of activity deserving of further investigation.

  1. Improving Biodiesel Fuel Properties by Modifying Fatty Ester Composition

    Biodiesel is an alternative to petroleum-derived diesel fuel composed of alkyl esters of vegetable oils, animal fats or other feedstocks such as used cooking oils. The fatty acid profile of biodiesel corresponds to that of its feedstock. Most feedstocks possess fatty acid profiles consisting mainl...

  2. Preparation of Jojoba Oil Ester Derivatives for Biodiesel Evaluation

    As a result of the increase in commodity vegetable oil prices, it is imperative that non-food oils should be considered as alternative feedstocks for biodiesel production. Jojoba oil is unusual in that it is comprised of wax esters as opposed to the triglycerides found in typical vegetable oils. A...

  3. A Convenient Synthesis of Amino Acid Methyl Esters

    Yaowu Sha

    2008-05-01

    Full Text Available A series of amino acid methyl ester hydrochlorides were prepared in good toexcellent yields by the room temperature reaction of amino acids with methanol in thepresence of trimethylchlorosilane. This method is not only compatible with natural aminoacids, but also with other aromatic and aliphatic amino acids.

  4. Activities of the Environmental Protection Agency concerning phthalate esters

    Newburg-Rinn, Steven D.

    1982-01-01

    EPA's activities concerning phthalate esters have been in four general areas, namely: (1) their status as toxic pollutants under the Clean Water Act; (2) their status as “new chemicals” under Section 5 of TSCA; (3) the potential risk to human beings posed by DEHP; and (4) finally, the need for testing phthalates with respect to their health and environmental effects.

  5. Chemistry for Kids. Ester, What's in My Food?

    Clarke, Michele; And Others

    1986-01-01

    Describes three teaching activities used in the Chemistry for Kids program which focus on how esters are chemicals partially responsible for the flavor of foods. Includes a discussion of a demonstration involving role-playing, a set of taste tests, and an activity using chewing gum to investigate odors in food. (TW)

  6. 4-Dimenthylaminopyridine or Acid-Catalyzed Synthesis of Esters: A Comparison

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

    2006-01-01

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

  7. Two-generation reproductive toxicity study of plant stanol esters in rats

    Whittaker, M.H.; Frankos, V.H.; Wolterbeek, A.P.M.; Waalkens-Berendsen, D.H.

    1999-01-01

    Plant stanol esters are intended for use as an ingredient in food to reduce the absorption of cholesterol from the gastrointestinal tract. Consumption of plant stanol esters has a demonstrated diet-derived public health benefit, as shown by numerous clinical studies. Plant stanol esters are ring-sat

  8. 21 CFR 172.816 - Methyl glucoside-coconut oil ester.

    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...

  9. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    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...

  10. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Partial phosphoric acid esters of polyester resins... of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section... prescribed conditions: (a) For the purpose of this section, partial phosphoric acid esters of...

  11. Mechanical and dielectric properties of epoxy/dicyclopentadiene bisphenol cyanate ester/glass fabric composites

    2008-02-01

    Full Text Available The impact and flexural strengths of epoxy-dicyclopentadiene bisphenol cyanate ester (EP-DCPDCE hybrid thermoset as well as the interlaminar shear strength (ILSS and flexural strength of the composites consisting of the hybrid thermoset and glass fabric were studied. It is found that the addition of epoxy resin (EP-51 can improve the mechanical properties, particularly, the impact strength of DCPDCE matrix and the ILSS of glass fabric reinforced composites. The improvements of the mechanical properties were obvious when the content of EP-51 is from 15 to 30 wt%. The investigations of the interphase of composites by scanning electron microscope (SEM and dynamic mechanical analysis (DMA confirm the improvement of mechanical properties of the composites. However the addition of EP-51 has negative effects on the thermal and dielectric property of the composites.

  12. Catalytic effect of carbon nanotubes on polymerization of cyanate ester resins

    2009-08-01

    Full Text Available Kinetic peculiarities of polycyclotrimerization process of dicyanate ester of bisphenol A (DCBA in the presence of multi-walled carbon nanotubes (MWCNTs have been investigated using Fourier Transform Infrared Spectroscopy (FTIR spectroscopy technique. It has been found that even very small amounts of MWCNTs (0.01–0.1 wt% catalyze the reaction of polycyclotrimerization of DCBA leading to formation of polycyanurate network (PCN/MWCNTs nanocomposite. However, some decrease in final degree of conversion for nanocomposites compared to the neat PCN within the temperature/time schedule used was observed. The kinetic rate constants increased with addition of MWCNTs and energies of activation were found to be significantly decreased even at low contents of MWCNTs.

  13. Sucrose ester based cationic liposomes as effective non-viral gene vectors for gene delivery.

    Zhao, Yinan; Zhu, Jie; Zhou, Hengjun; Guo, Xin; Tian, Tian; Cui, Shaohui; Zhen, Yuhong; Zhang, Shubiao; Xu, Yuhong

    2016-09-01

    As sucrose esters (SEs) are natural and biodegradable excipients with excellent drug dissolution and drug absorption/permeation in controlled release systems, we firstly incorporated SE into liposomes for gene delivery in this article. A peptide-based lipid (CDO14), Gemini-based quaternary ammonium-based lipid (CTA14), and mono-head quaternary ammonium lipid (CPA14), and SE as helper lipid, were prepared into liposomes which could enhance the interactions between liposomes and pDNA. Most importantly, the liposomes with helper lipid SE showed higher transfection and lower cytotoxicity than those without SE in Hela and A549 cells. It was also found that the transfection efficiency increased with the increase of SE content. The selected liposome, CDO14/SE, was able to deliver siRNA against luciferase for silencing gene in lung tumors of mice, with little in vivo toxicity. The results convincingly demonstrated SEs could be highly desirable candidates for gene delivery systems. PMID:27232309

  14. Poly(ester amide-Poly(ethylene oxide Graft Copolymers: Towards Micellar Drug Delivery Vehicles

    Gregory J. Zilinskas

    2012-01-01

    Full Text Available Micelles formed from amphiphilic copolymers are promising materials for the delivery of drug molecules, potentially leading to enhanced biological properties and efficacy. In this work, new poly(ester amide-poly(ethylene oxide (PEA-PEO graft copolymers were synthesized and their assembly into micelles in aqueous solution was investigated. It was possible to tune the sizes of the micelles by varying the PEO content of the polymers and the method of micelle preparation. Under optimized conditions, it was possible to obtain micelles with diameters less than 100 nm as measured by dynamic light scattering and transmission electron microscopy. These micelles were demonstrated to encapsulate and release a model drug, Nile Red, and were nontoxic to HeLa cells as measured by an MTT assay. Overall, the properties of these micelles suggest that they are promising new materials for drug delivery systems.

  15. Synthesis and Characterization of Novel Polyurethanes Based on Vegetable Oils Amide and Ester Polyols

    Vladimir YAKUSHIN

    2014-09-01

    Full Text Available Amide and ester type polyols were synthesized from rapeseed, sunflower and castor oils, and two types of ethanolamine (diethanolamine and triethanolamine at different molar ratio. Poly(urethane amides and polyester urethanes based on the synthesized polyols were prepared. The effect of the chemical structure of the obtained polyurethanes on density, glass transition temperature, thermal stability and mechanical properties was investigated. The influence of the content of OH groups in the synthesized polyols on the specified characteristics was estimated. It has been found that poly(urethane amides have better mechanical characteristics, but their thermal stability is lower than that of polyester urethanes. The chemical structure of the synthesized polyols and polyurethanes is qualitatively confirmed by IR-spectroscopy data. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4532

  16. Skin permeation of testosterone and its ester derivatives in rats.

    Kim, M K; Lee, C H; Kim, D D

    2000-04-01

    To establish the optimum conditions for improving the transdermal delivery of testosterone, we studied the relationship between the lipophilicity of testosterone ester derivatives and the rat skin permeation rate of testosterone. We performed a rat skin permeation study of testosterone and its commercially available ester derivatives, testosterone hemisuccinate, testosterone propionate and testosterone-17beta-cypionate, using an ethanol/water co-solvent system. The aqueous solubility and rat skin permeation rate of each drug, saturated in various compositions of an ethanol/water system, was determined at 37 degrees C. The aqueous solubility of testosterone and its ester derivatives increased exponentially as the volume fraction of ethanol increased up to 100% (v/v). The stability of testosterone propionate in both the skin homogenate and the extract was investigated to observe the enzymatic degradation during the skin permeation process. Testosterone propionate was found to be stable in the isotonic buffer solution and in the epidermis-side extract for 10h at 37 degrees C. However, in the skin homogenate and the dermis-side extract testosterone propionate rapidly degraded producing testosterone, implying that testosterone propionate rapidly degraded to testosterone during the skin permeation process. The steady-state permeation rates of testosterone in the ethanol/water systems increased exponentially as the volume fraction of ethanol increased, reaching the maximum value (2.69+/-0.69 microg cm(-2)h(-1)) at 70% (v/v) ethanol in water, and then decreasing with further increases in the ethanol volume fraction. However, in the skin permeation study with testosterone esters saturated in 70% (v/v) ethanol in water system, testosterone esters were hardly detected in the receptor solution, probably due to the rapid degradation to testosterone during the skin permeation process. Moreover, a parabolic relationship was observed between the permeation rate of testosterone and

  17. Encapsulating fatty acid esters of bioactive compounds in starch

    Lay Ma, Ursula Vanesa

    Interest in the use of many bioactive compounds in foods is growing in large part because of the apparent health benefits of these molecules. However, many of these compounds can be easily degraded during processing, storage, or their passage through the gastrointestinal tract before reaching the target site. In addition, they can be bitter, acrid, or astringent, which may negatively affect the sensory properties of the product. Encapsulation of these molecules may increase their stability during processing, storage, and in the gastrointestinal tract, while providing controlled release properties. The ability of amylose to form inclusion complexes and spherulites while entrapping certain compounds has been suggested as a potential method for encapsulation of certain molecules. However, complex formation and spherulitic crystallization are greatly affected by the type of inclusion molecules, type of starch, and processing conditions. The objectives of the present investigation were to: (a) study the effect of amylose, amylopectin, and intermediate material on spherulite formation and its microstructure; (b) investigate the formation of amylose and high amylose starch inclusion complexes with ascorbyl palmitate, retinyl palmitate, and phytosterol esters; (c) evaluate the ability of spherulites to form in the presence of fatty acid esters and to entrap ascorbyl palmitate, retinyl palmitate, and phytosterol esters; and (d) evaluate the effect of processing conditions on spherulite formation and fatty acid ester entrapment. Higher ratios of linear to branched molecules resulted in the formation of more and rounder spherulites with higher heat stability. In addition to the presence of branches, it appears that spherulitic crystallization is also affected by other factors, such as degree of branching, chain length, and chain length distribution. Amylose and Hylon VII starch formed inclusion complexes with fatty acid esters of ascorbic acid, retinol, or phytosterols

  18. Production of ethyl ester from crude palm oil by two-step reaction using continuous microwave system

    Sukritthira Ratanawilai

    2011-02-01

    Full Text Available The esterification of free fatty acids (FFA in vegetable oils with alcohol using an acid catalyst is a promising methodto convert FFA into valuable ester and obtain a FFA-free oil that can be further transesterified using alkali bases. In thiswork, the direct esterification reaction of FFA in crude palm oil to ethyl ester by continuous microwave was studied and theeffects of the main variables involved in the process, amount of catalyst, reaction time and the molar ratio oil/ alcohol, wereanalyzed. The optimum condition for the continuous esterification process was carried out with a molar ratio of oil to ethanol1:6, using 1.25%wt of H2SO4/oil as a catalyst, microwave power of 78 W and a reaction time 90 min. This esterification processshows that the amount of FFA was reduced from 7.5%wt to values around 1.4 %wt. Similar results were obtained followingconventional heating at 70°C, but only after a reaction time of 240 min. The esterified crude palm oil is suitable to perform thetransesterification process. Transesterification of the esterified palm oil has been accomplished with a molar ratio of oil toethanol of 1:8.5, 2.5%wt of KOH as a catalyst, a microwave power of 78 W, and a reaction time of 7 min. In addition, theproblem of glycerin separation was solved by mixing 10%wt of pure glycerin into the ethyl ester to induce the glycerin fromthe reaction to separated. This two-step esterification and transesterification process provided a yield of 78%wt with anester content of 97.4%wt. The final ethyl ester product met with the specifications stipulated by ASTM D6751-02.

  19. Synthesis of thermoplastic poly(ester-olefin elastomers

    Tanasijević Branka

    2004-01-01

    Full Text Available A series of thermoplastic poly(ester-olefin elastomers, based on poly(ethylene-stat-butylene, HO-PEB-OH, as the soft segment and poly (butylene terephthalate, PBT, as the hard segment, were synthesized by a catalyzed transesterification reaction in solution. The incorporation of soft hydrogenated poly(butadiene segments into the copolyester backbone was accomplished by the polycondensation of α, ω-dihydroxyl telechelic HO-PEB-OH, (PEB Mn = 3092 g/mol with 1,4-butanediol (BD and dimethyl terephthalate (DMT in the presence of a 50 wt-% high boiling solvent i.e., 1,2,4-trichlorobenzene. The molar ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 60:40. The synthesis was optimized in terms of both the concentration of catalyst, tetra-n-butyl-titanate (Ti(OBu4, and stabilizer, N,N'-diphenyl-p-phenylenediamine (DPPD, as well as the reaction time. It was found that the optimal catalyst concentration (Ti(OBu4 for the synthesis of these thermoplastic elastomers was 1.0 mmol/mol ester and the optimal DPPD concentration was 1.0 wt-%. The extent of the reaction was followed by measuring the inherent viscosity of the reaction mixture. The effectiveness of the incorporation of the soft segments into the copolymer chains was proved by Soxhlet extraction with chloroform. The molecular structures, composition and the size of the synthesized poly(ester-butylenes were verified by 1H NMR spectroscopy, viscometry of dilute solutions and the complex dynamic melt viscosity. The thermal properties of poly(ester-olefins were investigated by differential scanning calorimetry (DSC. The degree of crystallinity was also determined by DSC. The thermal and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA. The rheological properties of poly(ester-olefins were investigated by dynamic mechanical spectroscopy in the melt and solid state.

  20. Valimiskaotuse haavu raviva Rahvaliidu ajutine juht Ester Tuiksoo : "Meil on tugev küünarnukitunne" / Ester Tuiksoo

    Tuiksoo, Ester, 1965-

    2007-01-01

    Ilmunud ka: Severnoje Poberezhje, 28. märts 2007, lk. 2. Delfi lugejate küsimustele vastab Rahvaliidu ajutine juht ja lahkuva valitsuse põllumajandusminister Ester Tuiksoo, kellelt päriti nii erakonna maine taastamise, eesti toidu kui ka jopede jagamise kohta

  1. Simultaneous quantification of crocetin esters and picrocrocin changes in Chinese saffron by high-performance liquid chromatography-diode array detector during 15 years of storage

    Yingpeng Tong; Yongqiu Yan; Xingyi Zhu; Ruoxi Liu; Feng Gong; Ling Zhang; Ping Wang

    2015-01-01

    Background: Saffron, which is made up of the dried stigmas of Crocus sativus L., has been successfully cultivated in China since 1970s and Zhejiang province is now the largest producing area in China, but the contents of crocetin esters and picrocrocin in saffron from Zhejiang province has not been determined simultaneously by high-performance liquid chromatography (HPLC) and changes of these constituents in Chinese saffron during storage for years has not been studied. Object: To establish a...

  2. Lipase catalyzed ester synthesis for food processing industries

    Aravindan Rajendran

    2009-02-01

    Full Text Available Lipases are one of the most important industrial biocatalyst which catalyzes the hydrolysis of lipids. It can also reverse the reaction at minimum water activity. Because of this pliable nature, it is widely exploited to catalyze the diverse bioconversion reactions, such as hydrolysis, esterification, interesterification, alcoholysis, acidolysis and aminolysis. The property to synthesize the esters from the fatty acids and glycerol promotes its use in various ester synthesis. The esters synthesized by lipase finds applications in numerous fields such as biodiesel production, resolution of the recemic drugs, fat and lipid modification, flavour synthesis, synthesis of enantiopure pharmaceuticals and nutraceuticals. It plays a crucial role in the food processing industries since the process is unaffected by the unwanted side products. Lipase modifications such as the surfactant coating, molecular imprinting to suit for the non-aqueous ester synthesis have also been reported. This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries.Lipases são catalizadores industriais dos mais importantes, os quais catalizam a hidrólise de lipídeos. Também podem reverter a reação a um mínimo de atividade de água. Devido sua natureza flexível, é amplamente explorada para catalizar uma diversidade de reações de bioconversão como hidrólise, esterificação, interesterificação, alcoólise, acidólise e aminólise. A propriedade de síntese de esteres a partir de ácidos graxos e glicerol promoveu seu uso em várias sínteses de esteres. Os esteres sintetizados por lipases encontram aplicação em numerosos campos como a produção de biodiesel, resolução de drogas racêmicas, modificação de gorduras e lipídios, sintese de aromas, síntese de produtos farmacêuticos enantiopuro e nutracêuticos. As lipases possuem um papel crucial nas indústrias de

  3. Determination of vitamin A and vitamin E esters in infant formulae and fortified milk powders by HPLC: Use of internal standardisation.

    Woollard, David C; Bensch, Anja; Indyk, Harvey; McMahon, Adrienne

    2016-04-15

    An HPLC method is described using normal phase conditions with an unbonded silica column to determine concentrations of supplementary vitamin A and vitamin E esters and β-carotene in infant formulae. The method utilises selective dual-channel fluoresence for vitamins A and E and visible absorbance for β-carotene. An attribute of the method is the use of retinol propionate, α-tocopheryl propionate and all-E-β-apo-8'-carotenoic acid ethyl ester internal standards to compensate for analytical variations associated with these labile vitamins. Extraction is performed without saponification, with the aid of protease to remove vitamin encaspsulation and facilitate vitamin partition into hydrocarbon solvent. Figures of merit indicate the method is suitable for its intended purpose in the highly regulated infant formula environment, including liquid formulations. The method is extendable to whole milk powders where total vitamin A content data can be calculated by summing the innate long-chain vitamin A esters with the added esters. PMID:26616975

  4. Biodegradation of poly(lactic acid, poly(hydroxybutyrate-co-hydroxyvalerate, poly(butylene succinate and poly(butylene adipate-co-terephthalate under anaerobic and oxygen limited thermophilic conditions

    Jutakan Boonmee

    2016-01-01

    Full Text Available In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid (PLA, poly(hydroxybutyrate-co-hydroxyvalerate (PHBV, poly(butylene succinate (PBS, and poly(butylene adipate-co-terephthalate (PBAT were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of biodegradation after 75 days was investigated by weight loss determination, visual examination, and surface appearance by scanning electronic microscopy (SEM. Under both anaerobic and oxygen limited conditions, the complete degradation (100% weight loss was found only in PHBV after 75 days. The plastic degradations were ranked in the order of PHBV> PLA> PBS> PBAT. The percentage of weight losses were significantly different at p ≤ 0.05. However, for all studied plastics, the degradation under anaerobic and oxygen limited conditions did not significantly different at 95% confidence.

  5. List of Content

    Editor IJRED

    2014-05-01

    Full Text Available CONTENTS OF ARTICLES page Tin (II Chloride Catalyzed Esterification of High FFA Jatropha Oil: Experimental and Kinetics Study DOI: 10.14710/ijred.3.2.75-81 75-81 Ratna Dewi Kusumaningtyas, Prima Astuti Handayani, Rochmadi Rochmadi, Suryo Purwono, Arief Budiman   Utilization of Iles-Iles and Sorghum Starch for Bioethanol Production DOI: 10.14710/ijred.3.2.83-89 83-89 Kusmiyati Kusmiyati, Agus Sulistiyono   Premixed Combustion of Kapok (ceiba pentandra seed oil on Perforated Burner DOI: 10.14710/ijred.3.2.91-97 91-97 I.K.G. Wirawan, I.N.G. Wardana,        Rudy Soenoko, Slamet Wahyudi   Castor Seed from Melkasa Agricultural Research Centre, East Showa, Ethiopia and it’s biodiesel performance in Four Stroke Diesel Engine DOI: 10.14710/ijred.3. 3.2.99-105 99-105 Tesfahun Tegegne Akanawa, Haimanot Gebrehiwot Moges, Ramesh Babu, Daniel Bisrat   Economic feasibility of large scale PV water pumping applications utilizing real field data for a case study in Jordan DOI: 10.14710/ijred.3.2.107-117 107-117 Ibrahim Odeh   Development of Briquette from Coir Dust and Rice Husk Blend: An Alternative Energy Source DOI: 10.14710/ijred.3.2.119-123 119-123 Md. Hamidul Islam, Md. Mosharraf Hossain,Md. Abdul Momin   Performance, Emissions and Combustion Characteristics of a Single Cylinder Diesel Engine Fuelled with Blends of Jatropha Methyl Ester and Diesel DOI: 10.14710/ijred.3.2.125-131 125-131 Debasish Padhee, Hifjur Raheman   The characteristic changes of betung bamboo (Dendrocalamus asper pretreated by fungal pretreatment DOI: 10.14710/ijred.3.2.133-143 133-143 Widya Fatriasari, Wasrin Syafii, Nyoman J Wistara, Khaswar Syamsu, Bambang Prasetya   Influence of the Determination Methods of K and C Parameters on the Ability of Weibull Distribution to Suitably Estimate Wind Potential and Electric Energy DOI: 10.14710/ijred.3.2.145-154 145-154 Ruben M. Mouangue, Myrin Y. Kazet, Alexis Kuitche, Jean-Marie Ndjaka    

  6. Fragmentation Mechanism of Trans-α-Aryl-β-enamino Esters

    JIANG,Nan(蒋楠); WANG,Jian-Bo(王剑波); HE,Mei-Yu(何美玉)

    2002-01-01

    Electron impact-induced fragmentation mechanisms of trans-α-aryl-β-enamino esters were investigated using mass-analyzed ion kindetic energy (MIKE) spectrometry and high resolution accurate mass data. It was found that the main characteristic fragmentations of compounds studied were: an odd electron ion M+. - EtOH was formed by losing a neutral molecule of ethanol; and the skeletal rearrangements took place; and the ring opening reaction happened after losing a carbon monoxide;and the typical McLafferty rearrangement underwent in ester group. The cyclization reaction caused by losing neutral molecule of TsNH2 due to the ortho-effects of substituted group of aromatic ring was also observed.

  7. Organising pneumonia associated with fumaric acid ester treatment for psoriasis.

    Deegan, Alexander Paul

    2012-02-01

    INTRODUCTION: We present the case of a 49-year old male who presented with dyspnoea, cough, weight loss, night sweats and general malaise. He had been on treatment with oral fumaric acid esters (FAE, Fumaderm(R); Biogen Idec GmbH, Ismaning, Germany) for 6 months. METHODS: Report of a case. RESULTS: His chest X-ray showed patchy infiltrates in the left upper lobe which failed to resolve under empiric antibiotic therapy. A computed tomography of thorax revealed bilateral, mostly peripheral foci of consolidation with air bronchograms. Transbronchial biopsies showed a pattern of organising pneumonia (OP). CONCLUSIONS: Therapy with oral prednisolone (40 mg\\/day) resulted in a rapid clinical and radiological improvement. An association of FAE and OP has not previously been reported. Please cite this paper as: Deegan AP, Kirby B, Rogers S, Crotty TB and McDonnell TJ. Organising pneumonia associated with fumaric acid ester treatment for psoriasis.

  8. Processing and properties of SiC/vinyl ester nanocomposites

    Yong, Virginia; Hahn, H. Thomas

    2004-09-01

    The feasibility of improving polymer composites was investigated using 30 nm SiC nanoparticles in a vinyl ester resin. Even when the particle loading was less than 4% by weight, the viscosity of the nanoparticle suspension was found to increase much higher than that of microparticle suspension. This phenomenon may be the result of association between nanoparticles and polymer molecules, effectively making the nanoparticles larger. The resulting reduction in the mobility of polymer molecules also led to delayed curing. Ultrasonic mixing did not fully disperse the particles. As a result, the composite strength did not improve although the modulus increased. The use of a dispersant, methacryloxy propyl trimethoxy silane (MPS), improved the dispersion quality and hence the composite strength. The paper discusses the issues involved with processing, characterization and properties of SiC/vinyl ester nanocomposites. Methods of improving the nanocomposite quality are proposed in the paper as well.

  9. Production and Characterization of Jatropha Oil Methyl Ester

    P. Venkateswara Rao, G. Srinivasa Rao

    2013-04-01

    Full Text Available Biodiesel is emerging as a promising substitute of an alternative fuel and has gained significant attention due to the predicted depletion of conventional fuels availability in near future and environmental pollution concern. Utilization of biodiesel produced from Jatropha oil by transesterification process is one of the most promising options to replace conventional fossil diesel fuel. The physical properties such as density, Kinematic viscosity, flash point, carbon residue, Pour point and Cetane number were found out for diesel, Jatropha oil and Jatropha Oil Methyl Ester (JOME produced in the laboratory. Properties obtained for the Jatropha oil methyl ester are very closely matched with the values of conventional diesel fuel and can be used without any modification in the existing diesel engine.

  10. Fatty acid methyl esters production: chemical process variables

    Paulo César Narváez Rincón

    2010-06-01

    Full Text Available The advantages of fatty acid methyl esters as basic oleochemicals over fatty acids, the seventies world energy crisis and the use of those oleochemicals as fuels, have increased research interest on fats and oils trans-esterification. In this document, a review about basic aspects, uses, process variables and problems associated to the production process of fatty acid methyl esters is presented. A global view of recent researches, most of them focused in finding a new catalyst with same activity as the alcohol-soluble hydroxides (NaOH, KOH, and suitable to be used in transforming fats and oils with high levels of free fatty acids and water avoiding separation problems and reducing process costs, is also discussed.

  11. Hydrogels Formed by Oxo-ester Mediated Native Chemical Ligation

    Strehin, Iossif; Gourevitch, Dmitri; Zhang, Yong; Heber-Katz, Ellen; Messersmith, Phillip B.

    2013-01-01

    Oxo-ester mediated native chemical ligation (OMNCL) is a variation of the more general native chemical ligation (NCL) reaction that is widely employed for chemoselective ligation of peptide fragments. While OMNCL has been used for a variety of peptide ligations and for biomolecular modification of surfaces, it is typically practiced under harsh conditions that are unsuitable for use in a biological context. In this report we describe the use of OMNCL for polymer hydrogel formation, in-vitro c...

  12. Study on the Novel Dicyanate Ester Resin Containing Naphthalene Unit

    Hong Qiang YAN; Hong Yun PENG; Li JI; Guo Rong QI

    2004-01-01

    The novel dicyanate ester resin containing naphthalene unit (DNCY) was synthesized, and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analysis (EA).The thermal properties of DNCY resin was studied by thermal degradation analysis at a heating rate of 10 (C /min-1 in N2 and air. The DNCY resin exhibited better thermal and thermal-oxidative stability than bisphenol A dicyanate (BACY) resin.

  13. Synthesis of new radiotracers based of Ethyl Ester

    The in vivo study of a biochemical or physiological process requires the synthesis of specific radiotracers but also the targeting of these compounds so that they can reach their target tissue. Methodologies original synthesis associated with radioisotopes used, the quantities and chemical forms often have to be available developed. The chemistry of metal complexes booming, we were able to use the ethyl ester combined with technetium, forming a stable radiotracer. Finally, a counting of radioactivity in different rat's organs completed our study. (Author)

  14. Rapid Enzymatic Method for Pectin Methyl Esters Determination

    Lucyna Łękawska-Andrinopoulou; 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...

  15. Rheological behavior of castor oil mixed with different pyromellitic esters

    Boran Sorina; Tamas Andra

    2014-01-01

    The paper presents the rheological behavior study of castor oil mixed with different pyromellitic esters. The pyromellitic tetraesters used were obtained through the esterification of pyromellitic anhydride with a special alcohol of a complex alkyl-aryl structure (2-phenoxy-ethanol) in conjunction with a linear aliphatic alcohol with variable length (n-butanol, n-decanol). The influence of pyromellitic esters’ structure and concentration was determined, as ...

  16. DNA-Catalyzed Hydrolysis of Esters and Aromatic Amides

    Brandsen, Benjamin M.; Hesser, Anthony R.; Castner, Marissa A.; Chandra, Madhavaiah; Silverman, Scott K.

    2013-01-01

    We previously reported that DNA catalysts (deoxyribozymes) can hydrolyze DNA phosphodiester linkages, but DNA-catalyzed amide bond hydrolysis has been elusive. Here we used in vitro selection to identify DNA catalysts that hydrolyze ester linkages as well as DNA catalysts that hydrolyze aromatic amides, for which the leaving group is an aniline moiety. The aromatic amide-hydrolyzing deoxyribozymes were examined using linear free energy relationship analysis. The hydrolysis reaction is unaffec...

  17. Perfluorooxasulphonates of metals – the catalysts of esters manufacture

    Melnyk, Stepan

    2013-01-01

    The process of obtaining of aliphatic dibasic esters from dicarboxylic acids and C4-C5 alcohols in the presence of perfluoro(4–methyl–3,6–dioxaoctane)sulphonates of different metals has been researched. For the comparative estimation of catalysts their concentration was chosen identical and of such value that the rate of the process was limited exactly by the rate of chemical reaction. The dependences of technological characteristics of esterification process on catalyst nature and c...

  18. Antiwear and antioxidant studies of cardanol phosphate ester additives

    S. E. Mazzetto; L. D. M. Oliveira; D. Lomonaco; P. A. Veloso

    2012-01-01

    In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL), we report herein the synthesis and characterization (GC/MS and ¹H, 13C, and 31P NMR) of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500) and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performance...

  19. Processing and properties of SiC/vinyl ester nanocomposites

    Yong, V.; Hahn, H T

    2004-01-01

    The feasibility of improving polymer composites was investigated using 30 nm SiC nanoparticles in a vinyl ester resin. Even when the particle loading was less than 4% by weight, the viscosity of the nanoparticle suspension was found to increase much higher than that of microparticle suspension. This phenomenon may be the result of association between nanoparticles and polymer molecules, effectively making the nanoparticles larger. The resulting reduction in the mobility of polymer molecules a...

  20. Characterization and Process Development of Cyanate Ester Resin and Composite

    Frame, B.J.

    1998-03-01

    Cyanate ester (or polycyanate) resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption and radiation resistance. This report describes the results of a processing study to develop high-strength hoop-wound composite by the wet-filament winding method using Toray T1000G carbon fiber and YLA RS-14A polycyanate resin as the constituent materials. Process trials, tests and analyses were conducted in order to gain insight into factors that can affect final properties of the cured cyanate ester resin and its composites. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to cure is also crucial as it affects the T{sub g} of the resin and composite. Recommendations for reducing moisture contact with the resin during wet-winding are presented. High fiber volume fraction ({approximately}80%) composites wound and cured with these methods yielded excellent hoop tensile strengths (660 to 670 ksi average with individual rings failing above 700 ksi), which are believed to be the highest recorded strengths for this class of materials. The measured transverse properties were also exceptional for these high fiber fraction composites. Based on the available data, this cyanate ester resin system and its composites are recommended for space and vacuum applications only. Further testing is required before these materials can be recommended for long term use at elevated temperatures in an ambient air environment. The results of all analyses and tests performed as part of this study are presented as well as baseline process for fabricating thick, stage-cured composites. The manufacture of a 1 in. thick composite cylinder made with this process is also described.

  1. Synthesis of stearic acid triethanolamine ester over solid acid catalysts

    Tao Geng; Qiu Xiao Li; Ya Jie Jiang; Wei Wang

    2010-01-01

    The synthesis of stearic acid triethanolamine ester over solid acid catalysts was investigated.The results showed that the catalytic activity and selectivity of zirconium sulfate supported on SBA-15(6)(pore diameter 6 nm)is better than that of commonly used hypophosphorous acid,zirconium sulfate supported on MCM-41 and zirconium sulfate supported on SBA-15(9)(pore diameter 9 nm).

  2. Enzymatic synthesis and application of fatty acid ascorbyl esters

    Stojanović Marija M.; Carević Milica B.; Mihailović Mladen D.; Knežević-Jugović Zorica D.; Petrović Slobodan D.; Bezbradica Dejan I.

    2013-01-01

    Fatty acid ascorbyl esters are liposoluble substances that possess good antioxidative properties. These compounds could be synthesized by using various acyl donors for acylation of vitamin C in reaction catalyzed by chemical means or lipases. Enzymatic process is preferred since it is regioselective, performed under mild reaction conditions, with the obtained product being environmentally friendly. Polar organic solvents, ionic liquids, and supercritical fluids has been successfully use...

  3. Cellulose Ester / Polyolefin Binary Blends : Rheology, Morphology and Impact Properties

    Besson, François; Vanhille, Aurélie; Budtova, Tatiana

    2012-01-01

    Due to depletion of fossil resources and global environmental respect awareness, interest in biobased plastic materials is tremendously growing. Direct extraction of vegetal polymers like cellulose followed by a chemical modification to bring new properties is one of the paths to produce a bioplastic. Progressively replaced by oil-based polymers in the sixties, thermoplastic cellulose esters are now reconsidered for various materials applications. To improve mechanical weaknesses of cellulose...

  4. Synthesis and Pharmacology of Ester Modified (+/-)-threo-Methylphenidate Analogs

    Deutsch, Howard M.; Ye, Xiaocong Michael; Schweri, Margaret M.

    2014-01-01

    As part of a program to develop compounds with potential to treat cocaine abuse, eleven (+/-)-threo-methylphenidate (TMP; Ritalin) derivatives were synthesized and tested in rat striatal tissue preparations for inhibitory potency against [3H]WIN 35,428 binding (WIN) to the dopamine (DA) transporter, [3H]citalopram binding (CIT) to the serotonin transporter, and [3H]DA uptake. The ester function was replaced by other functional groups in all of the compounds; some also contained substituents o...

  5. L-Valine Ester of Cyclopropavir - a New Antiviral Prodrug

    Wu, Zhimeng; Drach, John C.; Prichard, Mark N.; Yanachkova, Milka; Yanachkov, Ivan; Bowlin, Terry L.; Zemlicka, Jiri

    2009-01-01

    The L-Valine ester of antiviral agent cyclopropavir, valcyclopropavir (6), was synthesized and evaluated for antiviral properties. Prodrug (6) inhibited replication of HCMV virus (Towne and AD169 strain) in HFF cells to approximately the same extent as the parent drug cyclopropavir (5). Stability of 6 toward hydrolysis at pH 7.0 roughly corresponds to that of valganciclovir (2). Pharmacokinetic studies in mice established that the oral bioavailability of valcyclopropavir (6) was 95%.

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

    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

  7. Characterization and Process Development of Cyanate Ester Resin Composites

    Frame, B.J.

    1999-05-23

    Cyanate ester resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption, and radiation resistance. This paper describes the results of a processing study to develop a high-strength hoop-wound composite by the wet-filament winding method using Toray TI 000G carbon fiber and YLA RS- 14A cyanate ester resin as the constituent materials. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to and during cure is also crucial as it affects the glass transition temperature of the resin and composite. Composite cylinders wound and cured with these methods yielded excellent ring tensile strengths both at room and elevated temperature. A summary of the measured mechanical and thermal property data for these composites is presented. Potential applications for these materials include flywheeI energy storage systems for space and satellite structures.

  8. Boric ester-type molten salt via dehydrocoupling reaction.

    Matsumi, Noriyoshi; Toyota, Yoshiyuki; Joshi, Prerna; Puneet, Puhup; Vedarajan, Raman; Takekawa, Toshihiro

    2014-01-01

    Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl)-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl)-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl) imide) (LiNTf2), the resulting 1-(2-hydroxyethyl)-3-methylimidazolium NTf2 was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN) to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by 1H-, 13C-, 11B- and 19F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10⁻⁴-1.6 × 10⁻⁵ S cm⁻¹ at 51 °C. This was higher than other organoboron molten salts ever reported. PMID:25405738

  9. Cyanate Ester and Phthalonitrile Impregnated Carbon Ablative TPS

    Boghozian, Tane; Stackpoole, Margaret M.; Gasch, Matt

    2016-01-01

    Phenolic resin has extensive heritage as a TPS (Thermal Protection Systems) material, however, alternative resin systems such as Cyanate Ester and Phthalonitrile may offer improved performance compared to state-of-the-art phenolic resin. These alternative resin systems may have higher char yield, higher char strength, lower thermal conductivity and improved mechanical properties. In current work at NASA Ames alternative resin systems were uniformly infused into fibrous substrates and preliminary properties characterized. The density of the cyanate ester infused in fibrous substrate ranged from 0.25-0.3 grams per cubic centimeter compared to PICA (Phenolic resin impregnated carbon ablative) having a density of approximately 0.25 grams per cubic centimeter. The density of Phthalonitrile varies from 0.22-0.25 grams per cubic centimeter. Initial formulations of these new resin systems were recently tested at the LARC HyMETs (Hypersonic Materials Environmental Test System) facility to evaluate their performance and data such as back face temperature, char yield, and recession are compared to PICA. Cyanate Ester and Phthalonitrile impregnated carbon ablative samples showed comparable performance to phenolic resin impregnated carbon ablative samples.

  10. Dough and hearth bread characteristics influenced by protein composition, protein content, DATEM, and their interactions

    Aamodt, A.; Magnus, E.M.; Hollung, K.; Uhlen, A.K.; Færgestad, E.M.

    2005-01-01

    The effects of protein composition, protein content, diacetyl tartaric acid ester of monoglycerides (DATEM), and their interaction on dough and bread characteristics were studied by small- and pilot-scale hearth bread baking, dough rheological testing using the Kieffer extensibility rig, and size di

  11. Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen

    Abdullah DK

    2012-09-01

    Full Text Available Norazlinaliza Salim,1 Mahiran Basri,1,2 Mohd BA Rahman,1 Dzulkefly K Abdullah,1 Hamidon Basri31Department of Chemistry, Faculty of Science, 2Laboratory of Biomolecular Medicine, Institute of Bioscience, 3Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, MalaysiaIntroduction: During recent years, there has been growing interest in the use of nanoemulsion as a drug-carrier system for topical delivery. A nanoemulsion is a transparent mixture of oil, surfactant and water with a very low viscosity, usually the product of its high water content. The present study investigated the modification of nanoemulsions with different hydrocolloid gums, to enhanced drug delivery of ibuprofen. The in vitro characterization of the initial and modified nanoemulsions was also studied.Methods: A palm kernel oil esters nanoemulsion was modified with different hydrocolloid gums for the topical delivery of ibuprofen. Three different hydrocolloids (gellan gum, xanthan gum, and carrageenan were selected for use. Ternary phase diagrams were constructed using palm kernel oil esters as the oil, Tween 80 as the surfactant, and water. Nanoemulsions were prepared by phase inversion composition, and were gradually mixed with the freshly prepared hydrocolloids. The initial nanoemulsion and modified nanoemulsions were characterized. The abilities of the nanoemulsions to deliver ibuprofen were assessed in vitro, using a Franz diffusion cell fitted with rat skin.Results: No significant changes were observed in droplet size (~16–20 nm but a significant difference in polydispersity indexes were observed before and after the modification of nanoemulsions using gellan gum, carrageenan, and xanthan gum. The zeta potentials of the initial nanoemulsions (–11.0 mV increased to –19.6 mV, –13.9 mV, and –41.9 mV, respectively. The abilities of both the initial nanoemulsion (T802 and the modified nanoemulsion to deliver ibuprofen

  12. Thermal Behavior,Nonisothermal Decomposition Reaction Kinetics of Mixed Ester Double-base Gun Propellants

    YI Jian-hua; ZHAO Feng-qi; XU Si-yu; GAO Hong-xu; HU Rong-zu

    2008-01-01

    The thermal decomposition behavior and nonisothermal reaction kinetics of the double-base gun propellants containing the mixed ester of triethyleneglycol dinitrate(TEGDN) and nitroglycerin(NG) were investigated by thermogravimetry(TG) and differential thermogravimetry(DTG),and differential scanning calorimetry(DSC) under the high-pressure dynamic ambience.The results show that the thermal decomposition processes of the mixed nitric ester gun propellants have two mass-loss stages.Nitric ester evaporates and decomposes in the first stage,and nitrocellulose and centralite Ⅱ(C2) decompose in the second stage.The mass loss,the DTG peak points,and the terminated temperatures of the two stages are changeable with the difference of the mass ratio of TEGDN to NG.There is only one obvious exothermic peak in the DSC curves under the different pressures.With the increase in the furnace pressure,the peak temperature decreases,and the decomposition heat increases.With the increase in the content of TEGDN,the decomposition heat decreases at 0.1 Mpa and rises at high pressure.The variety of mass ratio of TEGDN to NG makes few effect on the exothermic peak temperatures in the DSC curves at different pressures.The kinetic equation of the main exothermal decomposition reaction of the gun propellant TG0601 was determined as:da/dt-=1021.59(1-a)3e-2.60×104/T The reaction mechanism of the process can be classified as chemical reaction.The critical temperatures of the thermal explosion(Tbe and Tbp) obtained from the onset temperature(Te) and the peak temperature(Tp) are 456.46 and 473.40 K,respectively.△S≠,△H≠,and △G≠of the decomposition reaction are 163.57 J·mol-1·K-1,209.54 kJ·mol-1,and 133.55kJ·mol-1,respectively.

  13. MORPHOLOGY AND PROPERTIES OF SEGMENTED BLOCK COPOLY (ETHER ESTER)S FIBERS MADE BY GEL-DRAWING

    CHEN Shouxi; G.Wegner

    1988-01-01

    The segmented block copoly(ether ester)s were swollen by tetrahydrofuran (THF) at 60℃ and formed-fibers by gel-drawing. The morphology and properties of these fibers were investigated by optical and electron microscopes, X-ray diffraction, DSC and an Instron test machine. The band structure morphology was observed in the gel-drawing fibers. The molecular chains were highly oriented as proved by X-ray diffraction data. The results indicated that the gel-drawing fibers have much better mechanical properties than those obtained otherwise. The tensile strength and elastic modulus were found to be 280 MPa and 802 MPa, repsectively. The mechanism of the gel-drawing process was also discussed.

  14. Diversities of phthalate esters in suburban agricultural soils and wasteland soil appeared with urbanization in China

    The distribution of six priority phthalic acid esters (PAEs) in suburban farmland, vegetable, orchard and wasteland soils of Tianjin were obtained with gas chromatography-mass spectrometer analysis in 2009. Results showed that total PAEs varied from 0.05 to 10.4 μg g−1, with the median value as 0.32 μg g−1. Di-(2-ethylhexyl) phthalate and di-n-butyl phthalate are most abundant species. PAEs concentrations for the four types of soils exhibited decreasing order as vegetable soil > wasteland soil > farmland soil > orchard soil. PAEs exhibited elevated levels in more developed regions when compared with other studies. The agricultural plastic film could elevate the PAEs contents in soils. Principal component analysis indicated the emission from cosmetics and personal care products and plasticizers were important sources for PAEs in suburban soils in Tianjin. The higher PAEs contents in wasteland soils from suburban area should be paid more attention owing to large amounts of solid wastes appeared with the ongoing urbanization. - Highlights: ► PAEs levels in four types of soils in suburban area of Tianjin were studied. ► Vegetable soil and wasteland soil exhibited higher PAEs concentrations. ► PAEs in wasteland soils from suburban area of cities in China should be paid attention. - (1) Vegetable soil and wasteland soil exhibited higher PAEs concentrations; (2) PAEs in wasteland soils from suburban area of cities in China should be paid attention.

  15. A novel benzoxazine/cyanate ester blend with sea-island phase structures.

    Li, Xiaodan; Luo, Xiaoyong; Gu, Yi

    2015-07-15

    A novel cardanol-based benzoxazine (C-BOZ)/bisphenol A dicyanate ester (BADCy) blend with sea-island phase structures was successfully prepared via reaction-induced phase separation. The introduction of a long-chain alkyl group on the benzene ring significantly enhanced the thermodynamic differences between C-BOZ and BADCy. With the increase of the BADCy content, the Flory-Huggins interaction parameter (χ) of the blend decreased. By adjusting the ratio of the two components, sea-island phase separations were observed in C-BOZ/BADCy blends during the curing process. The dispersed phase was a C-BOZ rich phase, while the matrix was the crosslinked network composed of triazine rings and ring-opened C-BOZ. On the DMA curves of 9/1, 8/2 and 7/3 cured blends, there were two distinct Tgs. But with the increase of the BADCy content, the extent of phase separation was reduced. When the ratio reached 5/5, there was only one Tg because the viscosity of the blend was too high for phase separation to occur. PMID:26138358

  16. Effect of Arbuscular Mycorrhizal Inoculation on Plant Growth and Phthalic Ester Degradation in Two Contaminated Soils

    CHEN Rui-Rui; YIN Rui; LIN Xian-Gui; CAO Zhi-Hong

    2005-01-01

    A 60-day pot experiment was carried out using di-(2-ethylhexyl) phthalate (DEHP) as a typical organic pollutant phthalic ester and cowpea (Vigna sinensis) as the host plant to determine the effect of arbuscular mycorrhizal inoculation on plant growth and degradation of DEHP in two contaminated soils, a yellow-brown soil and a red soil. The air-dried soils were uniformly sprayed with different concentrations of DEHP, inoculated or left uninoculated with an arbuscular mycorrhizal (AM) fungus, and planted with cowpea seeds. After 60 days the positive impact of AM inoculation on the growth of cowpea was more pronounced in the red soil than in the yellow-brown soil, with significantly higher (P < 0.01)mycorrhizal colonization rate, shoot dry weight and total P content in shoot tissues for the red soil. Both in the yellowbrown and red soils, AM inoculation significantly (P < 0.01) reduced shoot DEHP content, implying that AM inoculation could inhibit the uptake and translocation of DEHP from roots to the aboveground parts. However, with AM inoculation no positive contribution to the degradation of DEHP was found.

  17. Crocetin ester improves myocardial ischemia via Rho/ROCK/NF-κB pathway.

    Huang, Zhiheng; Nan, Chen; Wang, Hanqing; Su, Qiang; Xue, Wenda; Chen, Yanyan; Shan, Xin; Duan, Jinao; Chen, Gang; Tao, Weiwei

    2016-09-01

    Crocetin ester (CE) is the active ingredient of Crocus sativus L. stigmas and Gardenia jasminoides Ellis fruit. The main purpose of the present study was to investigate the protective effect of CE on isoproterenol (ISO)-induced acute myocardial ischemia (AMI) through Rho/ROCK/NF-κB pathway and explore its underlying mechanism. Administration of CE (25 and 50mg/kg) could significantly reduce the serum contents of pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6). In addition, pretreatment with CE attenuated the contents of creatine kinase (CK), malondialdehyde (MDA) and the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD) in serum. Treatment with CE also improved the histopathological alteration and decreased the ST elevation. Furthermore, CE could ameliorate the cardiac expressions of Cu, Zn-superoxide dismutase (SOD1), MDA5, Rho, ROCK, p-IκB and p-NF-κBp65 in ISO-induced rats. It was assumed that CE might be a new therapeutic candidate for the treatment of AMI possibly through the inhibition of Rho/ROCK/NF-κB pathway. PMID:27285672

  18. Bio-detoxification of phorbol esters and other anti-nutrients of Jatropha curcas seed cake by fungal cultures using solid-state fermentation.

    Sharath, B S; Mohankumar, B V; Somashekar, D

    2014-03-01

    Jatropha seed cake, a byproduct after biodiesel extraction, has several anti-nutrients and toxins. Solid-state fermentation was carried out for the detoxification of the Jatropha seed cake (JSC) using different fungal cultures. The reduction in the anti-nutritional components such as tannins, phytates, saponins, lectin and protease inhibitor, and phorbol esters on 6th, 9th, and 12th day of fermentation was analyzed. The phorbol ester content in the unfermented JSC was 0.83 mg/g, and the maximum degradation of phorbol esters to the extent of 75% was observed in the case of JSC fermented with Cunninghamella echinulata CJS-90. The phytate degradation in the fermented JSC was in the range of 65-96%. There was a gradual reduction of saponin content in the JSC from 6th to 12th day, and the reduction of saponin was in the range of 55-99% after solid-state fermentation. The trypsin inhibitor activity and lectin were 1,680 trypsin inhibitor units (TIU) per gram and 0.32 hemagglutinating unit in the unfermented JSC, respectively. Trypsin inhibitor activity and lectin could not be detected in JSC after 12th day of solid-state fermentation. Tannins accounted for 0.53% in unfermented JSC, and there was a marginal increase of tannins after solid-state fermentation. The results indicate that biological detoxification could be a promising method to reduce anti-nutritional compounds and toxins in the JSC. PMID:24435764

  19. ESR studies on the orientation of cholesteryl ester in phosphatidylcholine multilayers.

    Grover, A K; Forrest, B J; Buchinski, R K; Cushley, R J

    1979-01-19

    The alignment of cholesteryl esters in multilayer phosphatidylcholine membranes was investigated using two spin-labelled cholesteryl esters: 10 : 3 ester (I) and 1 : 14 ester (II). The nitroxide label of I is aligned in the membrane with a very large angle of tilt (47 degrees +/- 1.5 degrees) with respect to the normal to the membrane surface; II does not show such a tilt. I gives spectra corresponding to immobilized label while II gives nearly isotropic spectra. Ascorbate treatment of the multilayers shows that the labels in I and II are not present at the phosphatidylcholine-water interphase. The data supports a 'horseshoe' configuration for the cholesteryl ester in the bilayer, with both the fatty acid chain and the cholesteryl moiety extending deep into the hydrophobic region of the membrane and with the ester linkage near the surface. PMID:215228

  20. Synthesis and Characteristics of an Aspartame Analogue, L-Asparaginyl L-3-Phenyllactic Acid Methyl Ester

    Hu TAO; Da-Fu CUI; You-Shang ZHANG

    2004-01-01

    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 ofamide 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.

  1. Lubricity of bio-based lubricant derived from chemically modified jatropha methyl ester

    N.W.M. Zulkifli

    2014-06-01

    Full Text Available Many studies have been undertaken with a view to using chemically modified vegetable oil as a bio-based lubricant. This research focused on tribological properties of trimethylolpropane (TMP ester, which is derived from renewable resource. This TMP ester was produced from jatropha methyl ester; it is biodegradable and has high lubricity properties. Two different conditions of lubrication are being investigated: extreme pressure and anti-wear. It was found that the TMP ester (Jatropha has better lubricity in terms of wear and friction compared to paraffin oil under extreme pressure conditions. TMP ester (Jatropha has similar characteristics to fully formulated lubricant (FFL, in terms of the coefficient of friction (CoF. In terms of the anti-wear condition, TMP ester (Jatropha has the lowest CoF; however it also has the high wear scar diameter. This is due to corrosion and chemical attack.

  2. Improved synthesis of amino acid and dipeptide chloromethyl esters using bromochloromethane

    Gomes, P; Santos, MI; Trigo, MJ; Castanheiro, R.; Moreira, R.

    2003-01-01

    Peptide chloromethyl esters are important compounds in prodrug synthesis. A simple, mild and efficient method for the synthesis of chloromethyl esters of N-blocked amino acids and dipeptides using exclusively bromochloromethane is reported. These N-blocked amino acid and dipeptide chloromethyl esters react readily with the carboxylic acid group of aspirin and with the sulfonamido group of the antimalarial sulfamethazine, to give the corresponding prodrugs.

  3. Characterization of structural stability of palm oil esters-based nanocosmeceuticals loaded with tocotrienol

    Ng, Sook Han; Woi, Pei Meng; Basri, Mahiran; Ismail, Zahariah

    2013-01-01

    Background Palm oil esters (POEs) are esters derived from palm oil and oleyl alcohol have great potential in the cosmetic and pharmaceutical industries due to the excellent wetting behavior of the esters without the oily feel. The role of oil-in-water nanoemulsions loaded with tocotrienol sedimentation behavior was studied. LUMiFuge® 116 particle separation analyzer was used to investigate the sedimentation behavior of POEs/tocotrienol/xanthan gum nanoemulsion system during centrifugation. An...

  4. Regioselective transesterifications of cyclohexanone derivatives containing beta-keto and malonic ester moieties

    Makarević, Janja; Žinić, Mladen

    1998-01-01

    The cyclohexanone derivatives 1–6 containing β-ketoester and α-disubstituted malonic ester moieties in the same molecule were found to undergo regioselective transesterifications with benzyl alcohol giving exclusively β-keto benzyl esters. On the contrary, the acyclic derivatives 9, 10 containing β-ketoester and α-monosubstituted malonic ester groups gave mixtures of transesterified products under the same reaction conditions.

  5. Phorbol ester effects on neurotransmission: interaction with neurotransmitters and calcium in smooth muscle.

    Baraban, J M; Gould, R J; Peroutka, S J; Snyder, S. H.

    1985-01-01

    Stimulation of the phosphatidylinositol cycle by neurotransmitters generates diacylglycerol, an activator of protein kinase C, which may regulate some forms of neurotransmission. Phorbol esters, potent inflammatory and tumor-promoting compounds, also activate protein kinase C. We demonstrate potent and selective effects of phorbol esters on smooth muscle, indicating a role for protein kinase C in neurotransmission. In rat vas deferens and dog basilar artery, phorbol esters synergize with calc...

  6. Formation and occurrence of dimer esters of pinene oxidation products in atmospheric aerosols

    Kristensen, Kasper; Enggrob, Kirsten L.; King, S. M.;

    2013-01-01

    and at low NOx concentrations demonstrated formation of two dimer esters, pinyl-diaterpenyl (MW 358) and pinonyl-pinyl dimer ester (MW 368), under both low- and high-temperature conditions. Concentration levels of the pinyl-diaterpenyl dimer ester were lower than the assumed first-generation oxidation...... valuable information on pinene oxidation processes and should be included in studies of formation and photochemical aging of biogenic secondary organic aerosols, especially at high temperatures....

  7. Quasi-Static and Fatigue Evaluation of Pultruded Vinyl Ester/E-Glass Composites

    Phifer, Stephan Paul

    1998-01-01

    QUASI-STATIC AND FATIGUE EVALUATION OF PULTRUDED VINYL ESTER/E-GLASS COMPOSITES Stephan P. Phifer (ABSTRACT) The quasi-static strength, stiffness, and fatigue properties of cross-ply, angle-ply, and quasi-isotropic vinyl ester/E-glass non-woven tricot stitched fabric composite laminates fabricated from the Continuous Resin Transfer Molding (CRTM) pultrusion process were the focus of this research. The tricot stitch and the 6% vinyl ester matrix cure shrinkage were found to play ...

  8. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.; Tricoli, M.

    1991-01-01

    An extensive number of aliphatic diphenyl esters, C6H5OOC(CH2)nCOOC6H5 (n = O,...,8,10,11,12,14), have been prepared in pure form. The crystalline melting points these esters exhibit an odd-even temperature behaviour, with the higher-melting even series (n even) displaying a minimum for n = 8 whi...... chloroform points to specific phenyl ester-solvent interactions, which obscure a potential s.e.c. conformational analysis of the diphenyl esters....

  9. Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

    Michel Marlier

    2007-01-01

    Full Text Available An enzymatic synthesis was developed on a new set of D-glucuronic acid esters and particularly the tetradecyl-D-glucopyranosiduronate also named tetradecyl D-glucuronate. Chromatographic analyses revealed the presence of the ester as a mixture of anomeric forms for carbon chain lengths superior to 12. TOF/MS and MS/MS studies confirmed the synthesis of glucuronic acid ester. The NMR study also confirmed the structure of glucuronic acid esters and clearly revealed an anomeric (α/β ratio equivalent to 3/2

  10. Experimental and Modeling Studies on the Synthesis and Properties of Higher Fatty Esters of Corn Starch

    Junistia, Laura; Sugih, Asaf K.; Manurung, Robert; Picchioni, Francesco; Janssen, Leon P.B.M.; 068883455; Heeres, Hero J.

    2009-01-01

    This paper describes a systematic study on the synthesis of higher fatty esters of corn starch (starch laurate and starch stearate) by using the corresponding vinyl esters. The reactions were carried out in DMSO using basic catalysts (Na(2)HPO(4), K(2)CO(3), and Na-acetate). The effect of the process variables (vinyl ester to starch ratio, catalyst intake, reaction temperature and type of the catalyst) on the degree of substitution (DS) of the starch laurate and starch stearate esters was det...

  11. Simultaneous quantification of crocetin esters and picrocrocin changes in Chinese saffron by high-performance liquid chromatography-diode array detector during 15 years of storage

    Yingpeng Tong

    2015-01-01

    Full Text Available Background: Saffron, which is made up of the dried stigmas of Crocus sativus L., has been successfully cultivated in China since 1970s and Zhejiang province is now the largest producing area in China, but the contents of crocetin esters and picrocrocin in saffron from Zhejiang province has not been determined simultaneously by high performance liquid chromatography (HPLC and changes of these constituents in Chinese saffron during storage for years has not been studied. Object: To establish a simple method quantification of the five main compounds including picrocrocin and four crocetin esters in saffron from main producing areas of China and study the influence of storage time on the changes of saffron constituents. Materials and Methods: A simple, sensitive, and accurate HPLC method was developed for simultaneous determination of five major active components in saffron and eight samples which collected from the same farm of Zhejiang province in different years were analyzed. Results: The correlation coefficient values (R2 > 0.9997 indicated good correlations between the investigated compounds’ concentrations and their peak areas within the test ranges. The limits of quantification and detection of the five compounds were 0.53–2.76 μg/mL and 0.11–0.77 μg/mL, respectively. The recoveries ranged from 94.67% to 101.31%, and the overall relative standard deviations for intra day and inter day were lower than 3.49%.The method was applied to study the changes of crocetin esters and picrocrocin contents in saffron samples during 15 years of storage. The losses of crocetin esters and picrocrocin in saffron with 1 year storage were 52.2% and 54.3%, respectively. The trend then declined during subsequent storage. Conclusion: The developed method can be applied to the intrinsic quality control of saffron.

  12. The Phorbol Ester Fraction from Jatropha curcas Seed Oil: Potential and Limits for Crop Protection against Insect Pests

    Alain Ratnadass

    2012-11-01

    Full Text Available The physic nut shrub, Jatropha curcas (Euphorbiaceae, has been considered as a “miracle tree”, particularly as a source of alternate fuel. Various extracts of the plant have been reported to have insecticidal/acaricidal or molluscicidal/anthelminthic activities on vectors of medical or veterinary interest or on agricultural or non-agricultural pests. Among those extracts, the phorbol ester fraction from seed oil has been reported as a promising candidate for use as a plant-derived protectant of a variety of crops, from a range of pre-harvest and post-harvest insect pests. However, such extracts have not been widely used, despite the “boom” in the development of the crop in the tropics during recent years, and societal concerns about overuse of systemic chemical pesticides. There are many potential explanations to such a lack of use of Jatropha insecticidal extracts. On the one hand, the application of extracts potentially harmful to human health on stored food grain, might not be relevant. The problem of decomposition of phorbol esters and other compounds toxic to crop pests in the field needing further evaluation before such extracts can be widely used, may also be a partial explanation. High variability of phorbol ester content and hence of insecticidal activity among physic nut cultivars/ecotypes may be another. Phytotoxicity to crops may be further limitation. Apparent obstacles to a wider application of such extracts are the costs and problems involved with registration and legal approval. On the other hand, more studies should be conducted on molluscicidal activity on slugs and land snails which are major pests of crops, particularly in conservation agriculture systems. Further evaluation of toxicity to natural enemies of insect pests and studies on other beneficial insects such as pollinators are also needed.

  13. Conformational analysis of acetylcholine and related choline esters

    Frydenvang, Karla Andrea; Jensen, B

    1996-01-01

    ,2'-[(1,4-dioxo-1,4-butanediyl)bis(oxy)]bis(N,N,N-trimethylet hanaminium)¿ iodide have been redetermined at 105 K in order to obtain detailed and accurate information on the geometry of choline esters and to elucidate the conformationally dependent changes of geometry. The conformational flexibility and the...... preferred conformations are elucidated based on results obtained from X-ray crystallographic studies and molecular mechanics (MM2) calculations. The usefulness of molecular mechanics calculations for quaternary ammonium ions is discussed....

  14. Diastereoselective Ugi reaction for the synthesis of unnatural amino esters

    Rafael Oliveira Rocha

    2012-06-01

    Full Text Available Multicomponent Reactions (MCR are useful reactions to obtain complex products by the simple mixture of 3 or more reactants. The classic Ugi reaction (4-UCR involves a mixture of an amine, aldehyde, isocyanide and a carboxylic acid, giving peptoides as products. Some modifications of this reaction have been reported, among which the use of amino acids and Lewis acids, such as titanium (IV chloride, to induce stereoselectivity in good ratio. In this work we demonstrate the efficiency of different Lewis acids in the modified Ugi reaction and good levels of diastereoselectivity and yields in the synthesis of unnatural secondary amino esters.

  15. Pharmaceutical potential of phorbol esters from Jatropha curcas oil.

    Devappa, Rakshit K; Malakar, Chandi C; Makkar, Harinder P S; Becker, Klaus

    2013-01-01

    Phorbol esters (PEs) are diterpenes present in Jatropha curcas L. seeds and have a myriad of biological activities. Since PEs are toxic, they are considered to be futile in Jatropha-based biodiesel production chain. In the present study, the extracted PEs from Jatropha oil were used as a starting material to synthesise pharmacologically important compound, prostratin. The prostratin synthesised from Jatropha showed identical mass with that of the reference standard prostratin, as determined by Nano-LC-ESI-MS/MS. Considering the rapid growth in Jatropha biodiesel industry, potential exists to harness large amount of PEs which can be further utilised to synthesise prostratin as a value added product. PMID:22913490

  16. A New Insecticidal Sesquiterpene Ester from Celastrus Angulatus

    Shao-peng Wei

    2009-03-01

    Full Text Available A new sesquiterpene polyol ester with a β-dihydroagarofuran skeleton, NW37 (1, and three known compounds NW13 (2, NW16 (3 and NW35 (4 were isolated by bioassay-guided fractionation from the highly polar MeOH extracts of the root bark of Celastrus angulatus. Their chemical structures were elucidated mainly by analyses of MS and NMR spectral data. The insecticidal activity of compound 1 against 4th instar Mythimna separata larvae with a KD50 value of 252.3 μg·g-1 was demonstrated.

  17. Ester Prodrugs of Ketoprofen: Synthesis, Hydrolysis Kinetics and Pharmacological Evaluation.

    Dhokchawle, B V; Tauro, S J; Bhandari, A B

    2016-01-01

    The ester prodrugs of ketoprofen with various naturally available antioxidants; menthol, thymol, eugenol, guiacol, vanillin and sesamol have been synthesized by the dicyclohexyl carbodiimide (DCC) coupling method, purified and characterized by spectral data. Further, their, partition coefficients have been determined as well as, hydrolytic studies performed. The synthesized compounds are more lipophilic compared to the parent moieties and are stable in acidic environment, which is a prerequisite for their oral absorption. Under gastric as well as intestinal pH conditions these prodrugs showed variable susceptibility towards hydrolysis. The title compounds when evaluated for anti-inflammatory, analgesic activities and ulcerogenicity, showed improvement over the parent drug. PMID:25894087

  18. Carboxylic ester hydrolases in mitochondria from rat skeletal muscle

    Kirkeby, S; Moe, D; Zelander, T

    1990-01-01

    organophosphate and organomercury. The activity of the indoxyl acetate esterases was enhanced by the non-ionic detergents Tween-40 and Lubrol. After freezing, thawing and high speed centrifugation most of the alpha-naphthyl acetate splitting enzymes were found in the supernatant, indicating that the enzymes are......A mitochondrial pellet, prepared from rat skeletal muscle, contained a number of carboxylic ester hydrolase isoenzymes. The esterases which split alpha-naphthyl acetate were organophosphate sensitive, whereas two out of three indoxyl acetate hydrolysing enzymes were resistant to both...

  19. Phthalic acid esters found in municipal organic waste

    Hartmann, Hinrich; Ahring, Birgitte Kiær

    2003-01-01

    Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2- ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more than half of...... bioavailability, which is enhanced at higher temperature and higher degradation of solid organic matter, to which the highly hydrophobic DEHP is adsorbed. The investigated reactor configuration with a thermophilic and a hyper-thermophilic treatment is, therefore, a good option for CD combining high rate...

  20. Hidrofilicidade de filmes de amido/poli(butileno adipato co-tereftalato (Pbat adicionados de tween 80 e óleo de soja Hydrophilicity of starch and poly(butylene adipate-co-terephthalate (Pbat films containing tween 80 and soybean oil

    Renata P. Herrera Brandelero

    2013-01-01

    Full Text Available A incorporação de amido ao polímero poli (butilenoadipatoco-tereftalato (PBAT através de blendas com alto teor de amido pode ser uma alternativa para obter embalagens biodegradáveis, minimizar custos e o uso de recursos não renováveis. No entanto, a adição de amido aumenta a permeabilidade ao vapor de água (PVA. A incorporação em filmes com amido de substâncias como óleos vegetais e surfactantes pode diminuir a hidrofilicidade, favorecendo as aplicações destes como embalagens. A hidrofilicidade dos filmes elaborados por blendas de amido/PBAT adicionados de óleo de soja (OS e tween 80 (TW foi avaliada considerando o efeito do OS e TW nas isotermas de sorção dos filmes, na PVA e nos coeficientes de difusão (Dw e solubilidade (β do vapor de água. Filmes com OS com ou sem TW apresentaram menor quantidade de água de sorção, sendo os filmes com menores quantidades de OS e sem TW menos hidrofílicos e menos permeáveis aos vapores de água. A adição de OS reduziu os valores de β e Dw dos filmes de amido/PBAT. O efeito foi relacionado com o aumento das porções hidrofóbicas e da compatibilidade entre o amido e PBAT na presença de OS.Incorporating starch into the poly(butylene adipate-co-terephthalate (PBAT polymer by means of blends with high starch contents is a possible option for producing biodegradable packaging using renewable resources and reducing costs. However, the addition of starch increases the water vapour permeability (WVP. The incorporation of substances as lipids and surfactants can reduce the hydrophilicity of films containing starch, favouring their use as packaging. The hydrophilicity of films produced from blends of starch/PBAT with added soybean oil (SO and tween 80 (TW was studied. The effects of these substances on the sorption isotherm, on the WVP and on the water vapour diffusion (Dw and solubility (β coefficients of the films were evaluated. The water sorption in films with SO, with or without TW

  1. Uptake and Metabolism of Phthalate Esters by Edible Plants.

    Sun, Jianqiang; Wu, Xiaoqin; Gan, Jay

    2015-07-21

    Phthalate esters (PAEs) are large-volume chemicals and are found ubiquitously in soil as a result of widespread plasticulture and waste disposal. Food plants such as vegetables may take up and accumulate PAEs from soil, potentially imposing human health risks through dietary intake. In this study, we carried out a cultivation study using lettuce, strawberry, and carrot plants to determine the potential of plant uptake, translocation, and metabolism of di-n-butyl phthalate (DnBP) and di(2-ethylhexyl) phthalate (DEHP) and their primary metabolites mono-n-butyl phthalate (MnBP) and mono(2-ethylhexyl) phthalate (MEHP). All four compounds were detected in the plant tissues, with the bioconcentration factors (BCFs) ranging from 0.16 ± 0.01 to 4.78 ± 0.59. However, the test compounds were poorly translocated from roots to leaves, with a translocation factor below 1. Further, PAEs were readily transformed to their monoesters following uptake. Incubation of PAEs and monoalkyl phthalate esters (MPEs) in carrot cell culture showed that DnBP was hydrolyzed more rapidly than DEHP, while the monoesters were transformed more quickly than their parent precursors. Given the extensive metabolism of PAEs to monoesters in both whole plants and plant cells, metabolism intermediates such as MPEs should be considered when assessing human exposure via dietary intake of food produced from PAE-contaminated soils. PMID:26090545

  2. Microreactors-A Powerful Tool to Synthesize Peroxycarboxylic Esters.

    Illg, Tobias; Knorr, Annett; Fritzsche, Lutz

    2015-01-01

    The synthesis of peroxycarboxylic esters, as one subgroup of organic peroxides, is characterized by a high thermal hazard potential regarding process safety. In case of failure in the production process, e.g., if the heat of reaction cannot be removed sufficiently fast, decomposition reactions can be triggered, and as a result, remarkable amounts of heat and gas can be released and can cause a high extent of damage. Multifarious technical and organizational measures are necessary to ensure the safe industrial production of peroxides. With the introduction of microreaction technology plenty of possibilities have been opened to carry out highly exothermic reactions in smaller volumes and with more efficient heat removal. In this paper we report the application of three different microstructured reactors, representing different mixing strategies, to synthesize two peroxymonocarboxylic esters, namely tert-butyl peroxypivalate and tert-butyl peroxy-2-ethylhexanoate. The following reactor types were considered: an orifice microreactor, a split and recombine microreactor and a capillary tube reactor in combination with ultrasonication. The efficiency of the two phase liquid/liquid reaction is expressed in comparison of conversion and selectivity. With microreaction technology a remarkable increase in space-time-yield, ranging from 12,500 kg·m(-3)·h(-1) to 414,000 kg·m(-3)·h(-1), is achieved. PMID:26703553

  3. Solvent-free enzymatic production of high quality cetyl esters.

    Serrano-Arnaldos, Mar; Máximo-Martín, María Fuensanta; Montiel-Morte, María Claudia; Ortega-Requena, Salvadora; Gómez-Gómez, Elisa; Bastida-Rodríguez, Josefa

    2016-04-01

    A solvent-free biocatalytic process for the synthesis of high quality cetyl laurate, myristate, palmitate and stearate has been optimized. This enzymatic procedure follows the fundamental principles of the Green Chemistry and lead to sustainable products, which can be labeled as natural and conform to the principal requirements for its use in high value-added goods. The four esters selected are the main components of spermaceti, a mixture of waxes very appreciated in cosmetic and pharmacy because of its physical properties and emolliency, which was formerly extracted from the head of the sperm whales. In this paper, the influence of the amount of biocatalyst, the commercially available Novozym(®) 435, and the temperature were studied in an open-air batch reactor before carrying out the synthesis in a high performance vacuum reactor with dry nitrogen input to shift the equilibrium towards product formation. Under optimal conditions, conversion was higher than 98.5 %. The characterization of the enzymatic cetyl esters puts in evidence that these are ultra-pure compounds, which have similar properties to the ones obtained through the conventional industrial processes with the extra benefit of being environmentally friendly. PMID:26801670

  4. N-hydroxysuccinimide-hippuran ester: application for radiolabeling of macromolecules

    A method for synthesis of N-hydroxysuccinimide ester of radioactive orthoiodohippurric acid (OIH-OSU) is developed in order to label macromolecules including antibodies. The OIH-OSU is prepared in 87% yield by reacting molar equivalents of o-iodohippuric acid, N:N-di-succinimidyl carbonate and pyridine in DMF overnight. The active labeled ester is obtained using high specific activity OIH in a similar synthetic protocol. Conjugation of OIH-OSU to human serum albumin is effected by incubating the reactants for half an hour at room temperature followed by purification of the labeled protein on a Sephadex G-100 column with activity yield of 44.3%. Organ distribution for the labeled albumin preparation and the commercial iodinated human serum albumin (RISA) in mice and rats is similar. As expected urinary excretion of radioactivity for the labeled preparation is greater than that of RISA reflecting the rapid urinary clearance of the OIH moiety released into the bloodstream. Hippuran labeling method offers a mild and rapid protocol for radioiodine labeling of proteins and antibodies for application in diagnostic nuclear medicine procedures

  5. New horizons for cholesterol ester transfer protein inhibitors.

    Schwartz, Gregory G

    2012-02-01

    High-density lipoprotein (HDL) cholesterol levels bear an inverse relationship to cardiovascular risk. To date, however, no intervention specifically targeting HDL has been demonstrated to reduce cardiovascular risk. Cholesterol ester transfer protein (CETP) mediates transfer of cholesterol ester from HDL to apolipoprotein B-containing particles. Most, but not all observational cohort studies indicate that genetic polymorphisms of CETP associated with reduced activity and higher HDL cholesterol levels are also associated with reduced cardiovascular risk. Some, but not all studies indicate that CETP inhibition in rabbits retards atherosclerosis, whereas transgenic CETP expression in mice promotes atherosclerosis. Torcetrapib, the first CETP inhibitor to reach phase III clinical development, was abandoned due to excess mortality associated with increases in aldosterone and blood pressure. Two other CETP inhibitors have entered phase III clinical development. Anacetrapib is a potent inhibitor of CETP that produces very large increases in HDL cholesterol and large reductions in low-density lipoprotein (LDL) cholesterol, beyond those achieved with statins. Dalcetrapib is a less potent CETP inhibitor that produces smaller increases in HDL cholesterol with minimal effect on LDL cholesterol. Both agents appear to allow efflux of cholesterol from macrophages to HDL in vitro, and neither agent affects blood pressure or aldosterone in vivo. Two large cardiovascular outcomes trials, one with anacetrapib and one with dalcetrapib, should provide a conclusive test of the hypothesis that inhibition of CETP decreases cardiovascular risk. PMID:22083134

  6. Microreactors—A Powerful Tool to Synthesize Peroxycarboxylic Esters

    Tobias Illg

    2015-12-01

    Full Text Available The synthesis of peroxycarboxylic esters, as one subgroup of organic peroxides, is characterized by a high thermal hazard potential regarding process safety. In case of failure in the production process, e.g., if the heat of reaction cannot be removed sufficiently fast, decomposition reactions can be triggered, and as a result, remarkable amounts of heat and gas can be released and can cause a high extent of damage. Multifarious technical and organizational measures are necessary to ensure the safe industrial production of peroxides. With the introduction of microreaction technology plenty of possibilities have been opened to carry out highly exothermic reactions in smaller volumes and with more efficient heat removal. In this paper we report the application of three different microstructured reactors, representing different mixing strategies, to synthesize two peroxymonocarboxylic esters, namely tert-butyl peroxypivalate and tert-butyl peroxy-2-ethylhexanoate. The following reactor types were considered: an orifice microreactor, a split and recombine microreactor and a capillary tube reactor in combination with ultrasonication. The efficiency of the two phase liquid/liquid reaction is expressed in comparison of conversion and selectivity. With microreaction technology a remarkable increase in space-time-yield, ranging from 12,500 kg·m−3·h−1 to 414,000 kg·m−3·h−1, is achieved.

  7. Synthesis and thermal behavior of new liquid crystals arylaldoxime esters

    Tavares, Aline; Arruda, Barbara C.; Boes, Elvis S.; Stefani, Valter; Stassen, Hubert K.; Campo, Leandra F.; Merlo, Aloir A., E-mail: aloir@iq.ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS (Brazil); Bechtold, Ivan H. [Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis-SC (Brazil)

    2012-05-15

    We report the synthesis of a series of liquid-crystalline materials based on arylaldoxime esters and the characterization of these materials by {sup 1}H, {sup 13}C NMR, ATR/FT-IR spectroscopy and elemental analysis. The chemical stability and liquid-crystalline as well as photophysical properties of the compounds are described being dependent on the heating/cooling cycles. The changes in chemical stability and the liquid crystals properties of arylaldoxime esters were observed during these thermal cycles by IR analysis. All samples underwent a thermal degradation yielding the corresponding nitriles and carboxylic acid as evidenced by IR and {sup 1}H NMR spectra. Due to the decomposition process, information about the mesomorphic behaviour is lost. The UV-Vis absorption spectra in solution display three absorption bands between 230 and 340 nm. The fluorescence spectra exhibit a broad and structureless emission band located at 430 nm. Ab initio calculations were performed to obtain information on the molecular structure and properties of the title compounds. (author)

  8. Ester-based solutions for rechargeable lithium cells

    In recent years, considerable progress has been made in rechargeable lithium technology. Current state-of-the-art secondary lithium cells generally employ solutions based on propylene carbonate or 2-methyl tetrahydrofuran, with 2-methyl tetrahydrofuran being the preferred solvent. Good cycle life has been achieved with these solutions at ambient temperature. However, poor low temperature performance and limited rate capabilities have prevented widespread use of these cells in DoD applications. These limitations are due, primarily, to the low conductivity of the electrolyte solutions employed. To extend the performance capabilities of rechargeable lithium cells, we have investigated the use of high conductivity ester-based electrolyte solutions utilizing methyl formate and methyl acetate as solvents. This paper discusses the initial results achieved with these solutions including electrochemical stability, lithium cyclability, and compatibility and cell performance with V/sub 2/O/sub 5/ and V/sub 6/O/sub 13/ cathode materials. These initial investigations with ester-based solutions have shown that LiAsF/sub 6/ + LiBF/sub 4//MF solutions offer all of the properties needed to meet the demanding performance requirements for DoD rechargeable lithium battery applications including high solution conductivities, electrochemical stability, and compatibility with cathode materials

  9. Subchronic organophosphorus ester-induced delayed neurotoxicity in mallards

    Hoffman, D.J.; Sileo, L.; Murray, H.C.

    1984-01-01

    Eighteen-week-old mallard hens received 0, 10, 30, 90, or 270 ppm technical grade EPN (phenylphosphonothioic acid O-ethyl-O-4-nitrophenyl ester) in the diet for 90 days. Ataxia was first observed in the 270-ppm group after 16 days, in the 90-ppm group after 20 days, in the 30-ppm group after 38 days; 10 ppm failed to produce ataxia. By the end of 90 days all 6 birds in the 270-ppm group exhibited ataxia or paralysis whereas 5 of 6 birds in the 90-ppm group and 2 of 6 birds in the 30-ppm group were visibly affected. Treatment with 30 ppm or more resulted in a significant reduction in body weight. Brain neurotoxic esterase activity was inhibited by averages of 16, 69, 73, and 74% in the 10-, 30-, 90-, and 270-ppm groups, respectively. Brain acetylcholinesterase, plasma cholinesterase, and plasma alkaline phosphatase were significantly inhibited as well. Distinct histopathological effects were seen in the 30-, 90-, and 270-ppm groups which included demyelination and degeneration of axons of the spinal cord. Additional ducks were exposed in a similar manner to 60-, 270-, or 540-ppm leptophos (phosphonothioic acid O-4-bromo-2,5-dichlorophenyl-O-methylphenyl ester) which resulted in similar behavioral, biochemical, and histopathological alterations. These findings indicate that adult mallards are probably somewhat less sensitive than chickens to subchronic dietary exposure to organophosphorus insecticides that induce delayed neurotoxicity.

  10. Purification and characterization of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China

    YU Xiao-dong; LI Bo; YU Zheng-ping

    2005-01-01

    Objective: To study the physical and chemical properties of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China. Methods :The arginine ester hydrolase (AEH) was isolated from the venom of Chinese Trimeresurus mucrosqumatus by a combination of ionexchange chromatography on DEAE-Sephadex A-50, CM-Sepharose Cl-6B and gel filtration on Sephadex G-100. Results: The purified protein named TM-AEH,a glycoprotein with carbohydrate content of 0.5 % neutral hexose and 0. 75 % sialic acid,a relative molecular mass of 29.0 kDa,and an isoelectric point (pI) of 5. 2. It shares with an extinction coefficient (E0.1%/cm) of 1.332 at 280 nm,consisted of 225 amino acid residues ,and migrated as a band under reduced or non-reduced condition in basic PAGE. TM-AEH was a highly thermostable protein and was stable to pH changes between 5 and 9. The optimum temperature and optimum pH were 55℃ and 8. 4 for its catalytic activity respectively,which was inhibited by Fe3+ and Cu2+. Conclusion:This protein can exhibit higher BAEE-hydrolysing activity and fibrinogenolytic activity as compared to that of whole venom.

  11. Identification of genes coding for putative wax ester synthase/diacylglycerol acyltransferase enzymes in terrestrial and marine environments.

    Lanfranconi, Mariana P; Alvarez, Adrián F; Alvarez, Héctor M

    2015-12-01

    Synthesis of neutral lipids such as triacylglycerols (TAG) and wax esters (WE) is catalyzed in bacteria by wax ester synthase/diacylglycerol acyltransferase enzymes (WS/DGAT). We investigated the diversity of genes encoding this enzyme in contrasting natural environments from Patagonia (Argentina). The content of petroleum hydrocarbons in samples collected from oil-producing areas was measured. PCR-based analysis covered WS/DGAT occurrence in marine sediments and soil. No product was obtained in seawater samples. All clones retrieved from marine sediments affiliated with gammaproteobacterial sequences and within them, most phylotypes formed a unique cluster related to putative WS/DGAT belonging to marine OM60 clade. In contrast, soils samples contained phylotypes only related to actinomycetes. Among them, phylotypes affiliated with representatives largely or recently reported as oleaginous bacteria, as well as with others considered as possible lipid-accumulating bacteria based on the analysis of their annotated genomes. Our study shows for the first time that the environment could contain a higher variety of ws/dgat than that reported from bacterial isolates. The results of this study highlight the relevance of the environment in a natural process such as the synthesis and accumulation of neutral lipids. Particularly, both marine sediments and soil may serve as a useful source for novel WS/DGAT with biotechnological interest. PMID:26228353

  12. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis. [quantitative structure-activity relationship, complete neglect of differential overlap

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of cationic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR-primeP(O)X, where R and R-prime are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrolysis rate constant.

  13. Potential grape-derived contributions to volatile ester concentrations in wine.

    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

  14. L-leucine methyl ester stimulates insulin secretion and islet glutamate dehydrogenase

    Knudsen, P; Kofod, Hans; Lernmark, A;

    1983-01-01

    Column perifusion of collagenase-isolated mouse pancreatic islets was used to study the dynamics of insulin release in experiments lasting for several hours. The methyl esters of L-leucine and L-arginine were synthesized. Whereas L-arginine methyl ester (L-arginine OMe) had no effect, L-leucine O...

  15. Combined approaches using sex pheromone and pear ester for behavioral disruption of codling moth (Lepidoptera: Tortricidae)

    Studies utilized the attractive properties of pear ester, ethyl (E,Z)-2,4-decadienoate, and codlemone, (E,E)-8,10-dodecadien-1-ol, the sex pheromone of codling moth, Cydia pomonella (L)., for behavioural disruption. Standard dispensers loaded with codlemone alone or in combination with pear ester (c...

  16. Syntheses of carbon-11 labeled piperidine esters as potential in vivo substrates for acetylcholinesterase

    A series of carbon-11 labeled N-methylpiperidinyl esters were prepared as potential in vivo substrates for acetylcholinesterase (AChE). Target compounds were designed based on the structure of N-[11C]methylpiperidin-4-yl propionate, an ester currently used to measure AChE enzymatic activity in the human brain, to examine the structure-activity relationship for in vivo enzymatic hydrolysis. Changes in steric bulk and in the ester order ('reverse' esters) were made. Addition of methyl groups was made to both the acid side chain (synthesis of N-[11C]methylmethylpiperidin-4-yl isobutyrate) and to the piperidine ring (syntheses of N-[11C]methyl-4-methylpiperidin-4-yl propionate, N-[11C]methyl-4-methylpiperidin-4-yl acetate, and N-[11C]methyl-3-methylpiperidin-4-yl propionate). Alterations of the order of the ester heteroatoms was accomplished through syntheses of the N-[11C]methyl-2,3- and 4-piperidinecarboxylic acid ethyl esters. Finally, an additional piperidine-based ester (N-[11C]methylpiperidin-2-yl)methyl propionate was also prepared. All carbon-11-labeled esters were prepared by N-[11C]methylation reactions, using the desmethyl precursors and no-carrier-added [11C]methyltriflate, and were obtained in decay-corrected yields (not optimized) of 10-40% and high specific activities

  17. Enhanced delivery of ketobemidone through porcine buccal mucosa in vitro via more lipophilic ester prodrugs

    Hansen, L.B.; Christrup, Lona Louring; Bundgaard, H.

    1992-01-01

    The in vitro penetration of ketobemidone and various ester prodrugs through porcine buccal mucosa in a modified Ussing chamber was investigated in order to support the selection of a prodrug derivative with optimal buccal absorption. The nine esters studied included carboxylic acid and carbonate...

  18. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.; Tricoli, M.

    1991-01-01

    An extensive number of aliphatic diphenyl esters, C6H5OOC(CH2)nCOOC6H5 (n = O,...,8,10,11,12,14), have been prepared in pure form. The crystalline melting points these esters exhibit an odd-even temperature behaviour, with the higher-melting even series (n even) displaying a minimum for n = 8 whi...

  19. Synthesis and physical properties of new coco-oleic dimer and trimer plus estolide branched esters

    Estolides are a class of esters based on vegetable oils that are formed when the carboxylic acid functionality of one fatty acid reacts at the site of unsaturation of another fatty acid to form an ester linkage. The objective of this preliminary study was to separate coco-oleic estolide into two com...

  20. Rapid ester biosynthesis screening reveals a high activity alcohol-O-acyltransferase (AATase) from tomato fruit.

    Lin, Jyun-Liang; Zhu, Jie; Wheeldon, Ian

    2016-05-01

    Ethyl and acetate esters are naturally produced in various yeasts, plants, and bacteria. The biosynthetic pathways that produce these esters share a common reaction step, the condensation of acetyl/acyl-CoA with an alcohol by alcohol-O-acetyl/acyltransferase (AATase). Recent metabolic engineering efforts exploit AATase activity to produce fatty acid ethyl esters as potential diesel fuel replacements as well as short- and medium-chain volatile esters as fragrance and flavor compounds. These efforts have been limited by the lack of a rapid screen to quantify ester biosynthesis. Enzyme engineering efforts have also been limited by the lack of a high throughput screen for AATase activity. Here, we developed a high throughput assay for AATase activity and used this assay to discover a high activity AATase from tomato fruit, Solanum lycopersicum (Atf-S.l). Atf1-S.l exhibited broad specificity towards acyl-CoAs with chain length from C4 to C10 and was specific towards 1-pentanol. The AATase screen also revealed new acyl-CoA substrate specificities for Atf1, Atf2, Eht1, and Eeb1 from Saccharomyces cerevisiae, and Atf-C.m from melon fruit, Cucumis melo, thus increasing the pool of characterized AATases that can be used in ester biosynthesis of ester-based fragrance and flavor compounds as well as fatty acid ethyl ester biofuels. PMID:26814045

  1. An electron spin resonance investigation of ester cation radicals at low temperatures

    The cation radicals of a series of esters have been produced by γ-irradiation of CFCl3 matrices containing the ester at 77 K. In previous work cations of methyl and ethyl esters were investigated. In this work we report results for larger esters. The cations of these esters are found to undergo immediate internal proton-transfer reactions involving specific sites on one of the alkyl substituents. For example, deuteration studies show that proton transfer occurs from the terminal methyl group in propyl formate to produce -OCH2CH2CH2; whereas in propyl acetate -OCH2CHCH3 is produced. The proton lost from these groups is assumed to add to an oxygen on the ester functional group. In the case of propyl acetate and esters with branched side chains we find that fragmentation reactions follow the proton transfer. In the cases of t-butyl acetate and isobutyl formate the fragmentation process occurs at 77 K and results in the isobutylene cation. Neopentyl formate gives evidence for the cation radical, an RCH2 radical and the fragmentation radical cation as the sample is annealed. These results show that ester cation radicals are highly reactive even at low temperatures where proton-transfer and fragmentation reactions are found. (author)

  2. Diarrhetic shellfish poisoning toxin esters in Danish blue mussels and surf clams

    Jørgensen, Kevin; Scanlon, Sine Hedegaard; Jensen, L.B.

    2005-01-01

    Until recently, little focus was given to the presence of diarrhetic shellfish poisoning ( DSP) toxin esters in seafood products. However, during the last few years, the occurrence of a high percentage of esters of the total amount of DSP toxins present in some seafood products has been observed...

  3. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    2010-07-01

    ... phosphate (generic). 721.6180 Section 721.6180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  4. 21 CFR 573.660 - Methyl glucoside-coconut oil ester.

    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...

  5. Enantioseparation of Racemic Naproxen Esters on Cellulose Tris (4-methylbenzoate) Chiral Stationary Phase

    2002-01-01

    Several kinds of racemic naproxen ester were successfully separated on CTMB chiral stationary phase with hexane-ethanol (98:2, vol./vol.) as the mobile phase. The influence of mobile phase composition and structure of racemic naproxen ester on chiral separation was studied and the chiral recognition mechanism of CTMB was discussed.

  6. Enantioseparation of Racemic Naproxen Esters on Cellulose Tris(4—methylbenzoate) Chiral Stationary Phase

    BaoHaiSHAO; XiuZhuXU; 等

    2002-01-01

    Several kinds of racemic naproxen ester were successfully separated on CTMB chiral stationary phase with hexane-ethanol(98:2,vol./vol.) as the mobile phase. The influence of mobile phase composition and structure of racemic naproxen ester on chiral separation was studied and the chiral recognition mechanism of CTMB was discussed.

  7. Selective enzymatic hydrolysis of C-terminal tert-butyl esters of peptides

    Eggen, I.F.; Boeriu, C.G.

    2007-01-01

    The present invention relates to a process for the selective enzymatic hydrolysis of C-terminal esters of peptide substrates in the synthesis of peptides, comprising hydrolysing C-terminal tert-butyl esters using the protease subtilisin. This process is useful in the production of protected or unprotected peptides.

  8. Selective enzymatic hydrolysis of C-terminal tert-butyl esters of peptides

    Eggen, I.F.; Boeriu, C.G.

    2007-01-01

    The present invention relates to a process for the selective enzymatic hydrolysis of C-terminal esters of peptide substrates in the synthesis of peptides, comprising hydrolysing C-terminal tert-butyl esters using the protease subtilisin. This process is useful in the production of protected or unpro

  9. Experimental and Modeling Studies on the Synthesis and Properties of Higher Fatty Esters of Corn Starch

    Junistia, Laura; Sugih, Asaf K.; Manurung, Robert; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2009-01-01

    This paper describes a systematic study on the synthesis of higher fatty esters of corn starch (starch laurate and starch stearate) by using the corresponding vinyl esters. The reactions were carried out in DMSO using basic catalysts (Na(2)HPO(4), K(2)CO(3), and Na-acetate). The effect of the proces

  10. Synthesis of Higher Fatty Acid Starch Esters using Vinyl Laurate and Stearate as Reactants

    Junistia, Laura; Sugih, Asaf K.; Manurung, Robert; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2008-01-01

    This paper describes the synthesis of long-chain fatty esters of corn starch (starch laurate and starch stearate) with a broad range in degree of substitution (DS = 0.24-2.96). The fatty esters were prepared by reacting the starch with vinyl laurate or vinyl stearate in the presence of basic catalys

  11. 77 FR 27126 - [alpha]-(p-Nonylphenol)-[omega]-hydroxypoly(oxyethylene) Sulfate and Phosphate Esters; Exemption...

    2012-05-09

    ... phosphate esters and the corresponding ammonium, calcium, magnesium, potassium, sodium, and zinc salts of... phosphate esters and the corresponding ammonium, calcium, magnesium, potassium, sodium, and zinc salts of..., ammonium, calcium, magnesium, potassium, sodium, and zinc salts when used as inert ingredients at...

  12. Synthesis of α-amino-β-keto-esters (β-oxodipeptides)

    Yanjie XU; Ligong CHEN

    2008-01-01

    The synthesis of α-amino-β-keto-esters (β-oxo dipeptides) was studied. Corresponding α-amino-β-keto-esters were prepared from BOC-(L)-Valine and BOC-(L)-isoleucine by coupling with (D,L)-threonine hydro-chloride and oxidation with Dess-Martin periodinane (DMP) with a total yield of 48% and 38%, respectively.

  13. Study of intermolecular interactions in the system of equilibrium catalytic transesterification of esters. 4. Fourier IR studies of the interaction of alcohols with esters

    Interaction of alcohols ROH with esters PhCOOR (R = Me, n-Bu, n-C7H15) in binary mixtures and in solutions in non-polar solvents was studies over a wide temperature range by means of Fourier IR spectroscopy. Even with alcohol taken in a great excess, two bands are observed in the region of ΝCO vibrations. The low-frequency band, correspond to the ester molecules bonded by hydrogen bonds of the C=O...HO type. The high-frequence band is shifted by 3-5 cm-1 with respect to the ester ΝCO band. The discreteness of the shift, indicates that an H-complex of one more type is formed between the alcohol and the ester. The analysis of data available allows one to conclude that the complex formation involves the alkoxyl oxygen atom of the ester. The formation enthalpies were determined for H-bond of n-BuOH with the esters and with transesterification catalysts B(OBu)3

  14. Sinapate esters provide greater UV-B attenuation than flavonoids in Arabidopsis thaliana (Brassicaceae)

    Mutants affected in flavonoid (tt4) or sinapate ester (fah1) biosynthesis were used to assess the relative importance of these phenolic UV photoprotectants in Arabidopsis. Flavonoid and sinapate ester absorption was more specific for UV-B than major nonphenolic chromophores in crude extracts. A new method of evaluating phenolic UV-B attenuation was developed using fluorescence analysis. When excited by UV-B, sinapate ester containing leaves and cotyledons had enhanced sinapate ester fluorescence and reduced chlorophyll fluorescence relative to those without sinapate esters. Although fluorescence analysis gave no evidence of UV-B attenuation by flavonoids, enhanced chlorophyll and protein loss were observed upon UV-B exposure in flavonoid-deficient leaves, suggesting they have another mechanism of UV-B protection. The hydroxycinnamates have been largely ignored as UV-B attenuating pigments. and the results indicate that greater attention should be paid to their role in attenuating UV-B

  15. Synthesis and application of glycolic esters in methanol-gasoline as bifunctional additives

    To explore new and multifunctional additives for methanol-gasoline, glycolic esters were synthesized and screened as phase stabilizer and saturation vapor pressure depressor. The effect of the esters structure on the efficiency was discussed. It was found that the stability of the blends depend on the length of the glycolic esters' alkoxy group, and hexyl glycolic and octyl glycolic were found to be the most effective in various gasoline-methanol blends. Additionally, the glycolic esters can depress the saturation vapor pressure of methanol-gasoline effectively as well, and decyl glycolic is the most effective one. With these data, it can be concluded that the glycolic esters have the great potential to be used as bifunctional gasoline-methanol additives. (author)

  16. Acid esterification-alkaline transesterification process for methyl ester production from crude rubber seed oil.

    Thaiyasuit, Prachasanti; Pianthong, Kulachate; Worapun, Ittipon

    2012-01-01

    This study aims to examine methods and the most suitable conditions for producing methyl ester from crude rubber seed oil. An acid esterification-alkaline transesterification process is proposed. In the experiment, the 20% FFA of crude rubber seed oil could be reduced to 3% FFA by acid esterification. The product after esterified was then tranesterified by alkaline transesterification process. By this method, the maximum yield of methyl ester was 90% by mass. The overall consumption of methanol was 10.5:1 by molar ratio. The yielded methyl ester was tested for its fuel properties and met required standards. The major fatty acid methyl ester compositions were analyzed and constituted of methyl linoleate 41.57%, methyl oleate 24.87%, and methyl lonolenate 15.16%. Therefore, the cetane number of methyl ester could be estimated as 47.85, while the tested result of motor cetane number was 51.20. PMID:22277892

  17. Regioselective Nitration of Nα,N1-Bis(trifluoroacetyl)-L-Tryptophan Methyl Ester: Efficient Synthesis of 2-Nitro and 6-Nitro-N-Trifluoroacetyl-L-Tryptophan Methyl Ester

    Osborne, Andrew S.; Som, Phanneth; Metcalf, Jessica L.; Phillips, Robert S.

    2008-01-01

    Nitration of Nα,N1-bis(trifluoroacetyl)-L-tryptophan methyl ester with HNO3 in acetic anhydride at 0° C provides Nα-trifluoroacetyl-2-nitro-L-tryptophan methyl ester in 67% yield, whereas nitration in trifluoroacetic acid at 0° C gives Nα-trifluoroacetyl-6-nitro-L-tryptophan methyl ester in 69% yield.

  18. Characteristics of Oxidative Storage Stability of Canola Fatty Acid Methyl Ester Stabilised with Antioxidants

    Tirto Prakoso

    2012-11-01

    Full Text Available The storage effects on the oxidation characteristics of fatty acid methyl ester of canola oil (CME were investigated in this study. CME stabilised with two antioxidants, i.e. 2,6-di-tert-bytyl-p-cresol (BHT and 6,6-di-tert-butyl-2, 2’-methylendi-p-cresol (BPH, was stored at 20, 40 and 60°C. The oxidation stability data were measured by the Rancimat test method and it was found that both BHT and BPH addition increased the oxidation resistance of the CME. The results showed that when BPH or BHT was added at a concentration of 100 ppm, the oxidation induction period of the neat CME samples increased from 5.53 h to 6.93 h and 6.14 h, respectively. Comparing both antioxidants, BPH proved to be more effective in increasing the oxidation resistance when both antioxidants were added at the same concentration. Furthermore, the oxidation induction time decreased linearly with the storage time. It was shown that the oxidation occurred rapidly in the first 8 weeks of storage. Later, a kinetic study was undertaken and first-order kinetics were applied to explain the oxidation characteristics of the CME added with antioxidants. This kinetic study focused on exploiting the activation energy values obtained from the Arrhenius equations. Also, the oxidation effects on other quality parameters, including acid value, peroxide value, kinematic viscosity, and water content, were examined.

  19. Determination of phthalate esters in teas and tea infusions by gas chromatography-mass spectrometry.

    Du, Liping; Ma, Lijuan; Qiao, Yang; Lu, Yan; Xiao, Dongguang

    2016-04-15

    Phthalate esters (PAEs), a group of environmental pollutants which are carcinogenic to human body, have been detected in teas. In this work, five PAEs in teas and tea infusions were quantitatively determined by a modified simultaneous distillation extraction (SDE) coupled with gas chromatography-mass spectrometry. After the optimization of SDE, the proposed method afforded a wide range of linearity and high linear regression coefficients with the limits of detection range of 0.24-3.72 μg/kg. The average recoveries were 79.83-116.67% for tea samples and 78.22-101.64% for tea infusions with all the relative standard deviations below 20%. The total content of five PAEs in teas was 1.135-3.734 mg/kg and the total dissolving ratio of five PAEs from tea to infusion was 19.05-28.07% for the selected tea samples. The risk assessment result of all the selected tea samples demonstrated that the population with the habit of drinking tea won't cause risk to human health. PMID:26675858

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

    Diaz-Felix, Walterio; Riley, Mark R.; Zimmt, Werner [Department of Agricultural and Biosystems Engineering, Shantz Building, Room 403, The University of Arizona, Tucson, AZ 85721 (United States); Kazz, Michael [Zelen Environmental, Tucson, AZ (United States)

    2009-04-15

    Biodiesel is a renewable fuel comprised of fatty acid methyl esters (FAME) derived from vegetable oils or animal fats. Comparisons between biodiesel and petroleum-based diesel have shown biodiesel to be effective in reducing exhaust emissions of carbon monoxide, hydrocarbons, particulate matter, and sulfur dioxide. While there are advantages of biodiesel over the traditional petroleum based diesel, biodiesel commercialization is limited by production cost that is dominated by the price of the feedstock (soybean oil). Yellow grease has the potential to be an effective feedstock with lower cost, but the chemical composition of these oils is variable depending on the source of collection and differs from that of virgin oil due to the presence of free fatty acids (FFA). Esterification has been previously demonstrated to reduce the FFA levels of YG; however, large quantities of methanol were required to drive the reaction to high yield. Methanol usage for processing and FFA content are the main factors affecting the economics of FAME production from YG. In this study, the relationship between composition and process variables was systematically studied. The effect of FFA ranging from 2% to 32% (w/w) was studied at three different molar ratios of methanol to FFA (4.5:1, 9:1, 18:1) and was found to have a non-linear relationship. Data obtained from this full factorial screening was used to develop a predictive statistical model to forecast the conversion based on initial FFA level and proportion of alcohol applied for esterification. (author)

  1. INFLUENCE OF PALM METHYL ESTER (PME AS AN ALTERNATIVE FUEL IN MULTICYLINDER DIESEL ENGINE

    Mohd Hafizil M. Yasin

    2012-12-01

    Full Text Available Palm oil is one of the vegetable oil, which is converted to biodiesel through a transesterification process using methanol as the catalyst. Palm oil biodiesel or palm methyl ester (PME can be used in diesel engines without any modification, and can be blended with conventional diesel to produce different proportions of PME-diesel blend fuels. The physical properties of PME were evaluated experimentally and theoretically. The effect of using neat PME as fuel on engine performance and emissions was evaluated using a commercial four-cylinder four-stroke IDI diesel engine. The experimental results on an engine operated with PME exhibited higher brake specific fuel consumption in comparison with the conventional fuel. With respect to the in-cylinder pressure and heat release rate, these increased features by over 8.11% and 9.3% with PME compared to conventional diesel. The overall results show that PME surpassed the diesel combustion quality due to its psychochemical properties and higher oxygen content.

  2. New amphiphilic PEG-b-P(ester-ether) micelles as potential drug nanocarriers

    Jeetah, Roubeena; Bhaw-Luximon, Archana; Jhurry, Dhanjay, E-mail: dhanjay.jhurry@gmail.com [University of Mauritius, ANDI Centre of Excellence for Biomedical and Biomaterials Research, MSIRI Building (Mauritius)

    2012-10-15

    A range of diblock and triblock copolymers of dioxanone and methyl dioxanone (MeDX) were synthesized by ring-opening polymerization of dioxanone and MeDX initiated by hydroxyl-terminated PEG (MPEG) or di-amino-terminated PEG (Jeffamine{sup Registered-Sign }) as macroinitiator in the presence of Sn(Oct){sub 2}. The copolymers exhibit amphiphilic behavior in water forming core-shell micelles in the size range 120-300 nm as measured by DLS. DSC measurements exhibit only one melting transition for all copolymers and confirm that increasing MeDX content of the copolymers lead to decreasing crystalline character and hydrophobic-hydrophilic chain entanglement. Anti-inflammatory drug ketoprofen was successfully loaded into the hydrophobic core of the micelles. Various key parameters such as micelle size, drug entrapment efficiency and drug release, which are dependent on crystalline structure and biodegradability characteristics of the hydrophobic core, could effectively be controlled by varying the dioxanone/MeDX ratio of the (ester-ether) copolymer.

  3. Stable isotope determination of ester and ether methyl moieties in plant methoxyl groups.

    Greule, Markus; Keppler, Frank

    2011-12-01

    Plant methoxyl groups of lignin and pectin have both distinct stable hydrogen isotope (δ(2)H) and carbon isotope (δ(13)C) values that can be used for studying environmental processes and for investigating the origin and authenticity of biomaterials. Up to now, the reported methods have been applied only to determine isotope values of the bulk plant methoxyl pool. In this work, we have applied several methods to distinguish between stable isotope ratios of methoxyl groups of pectin and the bulk plant methoxyl pool. Our results demonstrate that by applying alkaline hydrolysis to specifically cleave off the ester methyl moiety (pectin-like), we can distinguish δ(2)H and δ(13)C values of the pectin methoxyl pool from the bulk methoxyl pool. No measureable isotope discrimination was observed either during sample preparation or during analytical measurement. Furthermore, using this method, no major isotope difference in either the hydrogen or carbon isotope signature of the methoxyl groups of plant pectin and bulk matter from plant species such as leaves from trees, apples, carrots and potatoes was noted. We show the methanol released during alkaline hydrolysis of plant material and subsequently treated with hydriodic acid to be an excellent procedure to measure specifically and precisely the δ(13)C and δ(2)H isotope values of plant pectin-like methoxyl groups. This method is particularly advantageous when plant matter with a low methoxyl content has to be analysed. PMID:22004278

  4. Evaluation of hepatoprotective and antioxidant activity of astaxanthin and astaxanthin esters from microalga-Haematococcus pluvialis.

    Rao, A Ranga; Sarada, R; Shylaja, M D; Ravishankar, G A

    2015-10-01

    Effect of isolated astaxanthin (ASX) and astaxanthin esters (ASXEs) from green microalga-Haematococcus pluvialis on hepatotoxicity and antioxidant activity against carbon tetrachloride (CCl4) induced toxicity in rats was compared with synthetic astaxanthin (SASX). ASX, ASXEs, and SASX, all dissolved in olive oil, fed to rats with 100 and 250 μg/kg b.w for 14 days. They were evaluated for their hepatoprotective and antioxidant activity by measuring appropriate enzymes. Among the treated groups, the SGPT, SGOT and ALP levels were decreased by 2, 2.4, and 1.5 fold in ASXEs treated group at 250 μg/Kg b.w. when compared to toxin group. Further, antioxidant enzymes catalase, glutathione, superoxide dismutase and lipid peroxidase levels were estimated in treated groups, their levels were reduced by 30-50 % in the toxin group, however these levels restored by 136.95 and 238.48 % in ASXEs treated group at 250 μg/kg. The lipid peroxidation was restored by 5.2 and 2.8 fold in ASXEs and ASX treated groups at 250 μg/kg. The total protein, albumin and bilirubin contents were decreased in toxin group, whereas normalized in ASXEs treated group. These results indicates that ASX and ASXEs have better hepatoprotection and antioxidant activity, therefore can be used in pharmaceutical and nutraceutical applications and also extended to use as food colorant. PMID:26396419

  5. Exhaust gas assisted reforming of rapeseed methyl ester for reduced exhaust emissions of CI engines

    The nitrogen oxides (NOx) emissions of compression ignition (CI) engines fueled with biodiesel are generally higher compared to conventional diesel fuelling. Previous research work in CI engines has shown that the partial replacement of hydrocarbon fuels by hydrogen combined with exhaust gas recirculation (EGR) can reduce NOx and smoke emissions without significant changes to the engine efficiency. In the present study, the production of hydrogen-rich gas by catalytic exhaust gas assisted fuel reforming of rapeseed methyl ester (RME) has been investigated experimentally as a way to provide the required hydrogen for the reduction of biodiesel emissions. For comparison, tests with ultra low sulphur diesel (ULSD) were also performed. The reforming experiments were carried out in a mini reactor supplied with exhaust gas from a single cylinder CI engine. In all cases, the reactor inlet temperature was kept at 290-bar C which was chosen as a typical low exhaust gas temperature of diesel engines operating at part load. The engine operating condition (speed, load) was the same in all the tests and the reactor product gas was examined as a function of the reactor fuel flow rate and the composition of fuel and engine exhaust gas. Up to 17% hydrogen content of the reformer product was achieved and the results indicated that the main reactions in the reformer were the exothermic complete oxidation of part of the fuel and the endothermic steam reforming reaction. Reforming of RME produced more hydrogen with higher fuel conversion efficiency compared to ULSD reforming

  6. A comparative estimation of C.I. engine fuelled with methyl esters of punnai, neem and waste cooking oil

    D. Subramaniam, A. Murugesan, A. Avinashy

    2013-01-01

    In this experimental study, performance, emission, and combustion characteristics of methyl esters of Punnai, Neem, Waste Cooking Oil and their diesel blends in a C.I. engine was experimentally examined. For the study, Punnai oil methyl esters (POME), neem oil methyl esters (NOME), and Waste Cooking Oil Methyl Esters (WCOME) were prepared by tranesterification process. The Bio diesel-diesel blends were prepared by mixing 10%, 30%, 50%, and 70% of bio diesel with diesel. The effects of three m...

  7. Reaction with glutathione. A possible mechanism involved in rodent brain retention of a 99mTc SNS/S complex containing a pendant ester functionality

    The synthesis, characterization of MvO([CH3CH2N(CH2CH2S)2](p-S-Ph-COOCH2-CH3)) (M:99mTc: I, Re: II) is presented in this work, where a pendant ester function is attached to the monothiolate ligand. Chemical structure of I is established after chromatographic comparison with II, synthesized in macroscopic amounts. Complex II is fully characterized by classical methods of analysis showing that the compound adopts a distorted trigonal bipyramidal configuration around the metal. The two sulfur atoms of the tridentate ligand and the oxo group form the basal plane, while the remaining nitrogen atom of the tridentate ligand and the sulfur atom of the monothiolate ligand occupy the apices of the bipyramid. In vitro challenge experiments with glutathione (GSH) in neutral aqueous medium demonstrate, that I suffers nucleophilic attack by GSH and thereby transformation to a more hydrophilic daughter metal compound. Formation of the latter depends on time and GSH concentration. Tissue distribution in mice shows minor retention in brain. As rodent brain presents no esterases to hydrolyze the ester group of I, while the intracerebral content in GSH amounts to 2 mM, the above described mechanism is suspected for the observed brain retention. However, in primate brain cells retention of I may additionally involve the hydrolysis of the ester function to the corresponding acid, as already revealed by preliminary in vitro experiments using esterase incubates. (author)

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

    2010-07-01

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

  9. Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry

    Engvild, Kjeld Christensen; Egsgaard, Helge; Larsen, Elfinn

    1980-01-01

    methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum...

  10. Properties of a new gasoline oxygenate blend component: 3-Hydroxybutyrate methyl ester produced from bacterial poly-3-hydroxybutyrate

    Wang, Shen Yu.; Wang, Zhen; Liu, Ming Ming; Zhang, Xiao Jun [Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong (China); Xu, Yu. [Oilcare Oil Test Laboratory of China National Analytical Center, 6th Floor, Building 34, No. 100, Xian Lie Zhong Road, Guangzhou 510000 (China); Chen, Guo-Qiang [Dept Biological Sciences and Biotechnology, School of Life Science, Tsinghua University, Beijing 100084 (China)

    2010-08-15

    3-Hydroxybutyrate methyl ester (HBME) was prepared from hydrolysis of bacterial poly-3-hydroxybutyrate (PHB) using methanol as an esterification agent in the presence of sulfuric acid. Physicochemical and fuel related properties of HBME were studied for the possibility of using HBME as a gasoline additive. When HBME was blended with 97 gasoline in volume ratios of 5%, 8.5%, 10%, 15% and 20%, respectively, it was found that HBME had similar or better properties as a fuel additive compared with ethanol in terms of oxygen content, dynamic viscosity, flash point and boiling point. The blending of HBME and gasoline showed only little difference compared with the 97 gasoline in terms of octane number (RON) and distillation ranges, especially for the HBME 8.5% and 10% blends, which demonstrated an over 93% combustion heat of gasoline with less than 5% reduction in RON. (author)

  11. Effect of Intumescent Flame Retardants on the Properties of Polyurethanes Based on Tall Oil Fatty Acids Esters

    Vladimir Yakushin

    2015-06-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 The efficiency of using intumescent flame retardants in polyurethane coatings based on tall oil fatty acids esters was assessed. The influence of the content of each of the flame retardants (ammonium polyphosphate, melamine and pentaerythriol separately on the flammability parameters of wood samples with polyurethane coatings in a cone calorimeter test, as well as on the thermal and mechanical properties of the polyurethane itself, were investigated. the effect of the ratios of double and triple combinations of the mentioned flame retardants on the specified properties was studied. It has been found that, for the given type of polyester urethane, ammonium polyphosphate decreases the flammability of polyurethane to the greatest extent. Melamine, and melamine in combination with ammonium polyphosphate, decrease the smoke release upon polyurethane combustion. DOI: http://dx.doi.org/10.5755/j01.ms.21.2.5784

  12. Effects of prolonged administration of phthalate ester on the liver

    Di(2-ethylhexyl)phthalate (DEHP) was administered to male rats in the diet at concentrations of 2.0, 0.2, and 0.02% for up to 102 weeks. Low doses resulted in moderate increases in certain hepatic enzymes during the initial phase of exposure and in a continuous increase in the activities of these same enzymes throughout the treatment period. An increased level of dolichol and decreased concentration of dolichyl-P were observed. Furthermore, the rate of protein glycosylation diminished. Liver biopsies from patients subjected to hemodialysis demonstrated an increased number of peroxisomes. Phthalate ester seems to interfere with protein turnover, so that the half-life of total mitochondrial and microsomal protein is considerably increased

  13. Antiwear and antioxidant studies of cardanol phosphate ester additives

    Mazzetto, S.E.; Oliveira, L.D.M.; Lomonaco, D.; Veloso, P.A., E-mail: selma@ufc.br [Lab. de Produtos e Tecnologia em Processos (LPT), Dept. de Quimica Organica e Inorganica, Universidade Federal do Ceara, Fortaleza, CE (Brazil)

    2012-07-15

    In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL), we report herein the synthesis and characterization (GC/MS and {sup 1}H, {sup 13}C, and {sup 31}P NMR) of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500) and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performances promoted by the bioadditives evaluated, especially for the thiophosphorylated derivative, which notably reduced the sludge residue and the acidity index of the oxidized oil (0.52 mg NaOH/g sample) and also improved the diesel lubricity, reducing the wear of metal parts by more than 50% (330 {Mu}m). Keywords: Cardanol; Antiwear; Antioxidant; Diesel; Mineral oil. (author)

  14. Starch fatty esters for potential use in petroleum industry

    Dias, Fernanda; de Souza, Roberta; Lucas, Elizabete

    2013-01-01

    The aim of this study was to obtain and characterize starch fatty esters with variations in the hydrophilic/lipophilic balance and to assess whether these samples have potential application in oil-based drilling fluids. The variation in the hydrophobicity of the samples was verified by means of viscosity tests, which suggested that the products had varied solubility parameters, near the value of the solvent n-paraffin. Отримано і охарактеризовано жирні естери крохмалю при зміні гідрофільно/л...

  15. Antiwear and antioxidant studies of cardanol phosphate ester additives

    In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL), we report herein the synthesis and characterization (GC/MS and 1H, 13C, and 31P NMR) of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500) and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performances promoted by the bioadditives evaluated, especially for the thiophosphorylated derivative, which notably reduced the sludge residue and the acidity index of the oxidized oil (0.52 mg NaOH/g sample) and also improved the diesel lubricity, reducing the wear of metal parts by more than 50% (330 Μm). Keywords: Cardanol; Antiwear; Antioxidant; Diesel; Mineral oil. (author)

  16. Antiwear and antioxidant studies of cardanol phosphate ester additives

    S. E. Mazzetto

    2012-09-01

    Full Text Available In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL, we report herein the synthesis and characterization (GC/MS and ¹H, 13C, and 31P NMR of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500 and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performances promoted by the bio-additives evaluated, especially for the thiophosphorylated derivative, which notably reduced the sludge residue and the acidity index of the oxidized oil (0.52 mg NaOH/g sample and also improved the diesel lubricity, reducing the wear of metal parts by more than 50% (330 μm.

  17. Improved preparation of halopropyl bridged carboxylic ortho esters

    Richard J. Petroski

    2008-10-01

    Full Text Available Bridged ortho esters of 3-halopropyl carboxylic acids were prepared by esterification of 3-methyl-3-hydroxymethyloxetane with 3-bromopropionyl chloride and pyridine in dry THF, followed by rearrangement with boron trifluoroetherate, to afford 1-(2-bromoethyl-4-methyl-2,6,7-trioxabicyclo[2,2,2]-octane. The 1-(2-iodoethyl-4-methyl-2,6,7-trioxabicyclo[2,2,2]-octane analogue could not be prepared directly by halogen exchange of 1-(2-bromoethyl-4-methyl-2,6,7-trioxabicyclo[2,2,2]-octane but could be prepared by halogen exchange of the (3-methyloxetan-3-ylmethyl 3-bromopropanoate with a mixture of sodium iodide and anhydrous sodium sulfate in acetone, followed by rearrangement with boron trifluoroetherate.

  18. Three New Triterpene Esters from Pumpkin (Cucurbita maxima Seeds

    Takashi Kikuchi

    2014-04-01

    Full Text Available Three new multiflorane-type triterpene esters, i.e. 7α-hydroxymultiflor-8-ene-3α,29-diol 3-acetate-29-benzoate (1, 7α-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (2, and 7β-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (3, were isolated from seeds of Cucurbita maxima, along with the known compound, multiflora-7,9(11-diene-3α,29-diol 3,29-dibenzoate (4. Compound 1 exhibited melanogenesis inhibitory activities comparable with those of arbutin. In cytotoxicity assays, compounds 1 and 3 exhibited weak cytotoxicity, with IC50 values of 34.5–93.7 μM against HL-60 and P388 cells.

  19. Three new triterpene esters from pumpkin (Cucurbita maxima) seeds.

    Kikuchi, Takashi; Ueda, Shinsuke; Kanazawa, Jokaku; Naoe, Hiroki; Yamada, Takeshi; Tanaka, Reiko

    2014-01-01

    Three new multiflorane-type triterpene esters, i.e. 7α-hydroxymultiflor-8-ene-3α,29-diol 3-acetate-29-benzoate (1), 7α-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (2), and 7β-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (3), were isolated from seeds of Cucurbita maxima, along with the known compound, multiflora-7,9(11)-diene-3α,29-diol 3,29-dibenzoate (4). Compound 1 exhibited melanogenesis inhibitory activities comparable with those of arbutin. In cytotoxicity assays, compounds 1 and 3 exhibited weak cytotoxicity, with IC50 values of 34.5-93.7 μM against HL-60 and P388 cells. PMID:24743937

  20. Interaction between Lubricants Containing Phosphate Ester Additives and Stainless Steels

    David W. Johnson

    2013-05-01

    Full Text Available One way to improve fuel efficiency in today’s jet aircraft engines is to create an environment for higher operating temperatures and speeds. New and improved lubricants and bearing materials must be developed to remain stable in these elevated operating temperatures. Three lubricants, with varying amounts of tricresyl phosphate added as an anti-wear/extreme pressure additive were tested on two different stainless steels at varying temperatures ranging from 300 °C to 350 °C in vacuum. Significant decomposition of the lubricant base-stocks and the phosphate ester additive did occur in most of the trials resulting in the formation of carboxylic acids and phenols. In these cases a film containing phosphorus was deposited onto the stainless steel substrate.

  1. Reaction of gallocyanine methyl ester with uranyl ions

    The reaction of gallocyanine methyl ester with uranyl ions was studied spectrophotometrically in slightly acid or neutral solutions of 40% (m/m) ethanol. A violet complex of UO2L2 is formed at pH>5. The conditional stability constants of the complex in the pH range 6-7.4 and the equilibrium constants of the coordination reaction were derived from the concentration curves and the continuous variations curves. The optimum conditions were sought for the spectrophotometric determination of uranium based on the occurrence of the UO2L2 complex. The relative standard deviation obtained for a uranium concentration of 106 μg.l-1 was ssub(r)=2.13%. (author)

  2. Reaction of gallocyanine methyl ester with uranyl ions

    Kotoucek, M.; Hrbkova, M. (Palackeho Univ., Olomouc (Czechoslovakia). Prirodovedecka Fakulta)

    1984-09-01

    The reaction of gallocyanine methyl ester with uranyl ions was studied spectrophotometrically in slightly acid or neutral solutions of 40% (m/m) ethanol. A violet complex of UO/sub 2/L/sub 2/ is formed at pH>5. The conditional stability constants of the complex in the pH range 6-7.4 and the equilibrium constants of the coordination reaction were derived from the concentration curves and the continuous variations curves. The optimum conditions were sought for the spectrophotometric determination of uranium based on the occurrence of the UO/sub 2/L/sub 2/ complex. The relative standard deviation obtained for a uranium concentration of 106 ..mu..g.l/sup -1/ was ssub(r)=2.13%.

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

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

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

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

    1986-12-01

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

  5. Short-chain flavor ester synthesis in organic media by an E. coli whole-cell biocatalyst expressing a newly characterized heterologous lipase.

    Guillaume Brault

    Full Text Available Short-chain aliphatic esters are small volatile molecules that produce fruity and pleasant aromas and flavors. Most of these esters are artificially produced or extracted from natural sources at high cost. It is, however, possible to 'naturally' produce these molecules using biocatalysts such as lipases and esterases. A gene coding for a newly uncovered lipase was isolated from a previous metagenomic study and cloned into E. coli BL21 (DE3 for overexpression using the pET16b plasmid. Using this recombinant strain as a whole-cell biocatalyst, short chain esters were efficiently synthesized by transesterification and esterification reactions in organic media. The recombinant lipase (LipIAF5-2 showed good affinity toward glyceryl trioctanoate and the highest conversion yields were obtained for the transesterification of glyceryl triacetate with methanol. Using a simple cetyl-trimethylammonium bromide pretreatment increased the synthetic activity by a six-fold factor and the whole-cell biocatalyst showed the highest activity at 40°C with a relatively high water content of 10% (w/w. The whole-cell biocatalyst showed excellent tolerance to alcohol and short-chain fatty acid denaturation. Substrate affinity was equally effective with all primary alcohols tested as acyl acceptors, with a slight preference for methanol. The best transesterification conversion of 50 mmol glyceryl triacetate into isoamyl acetate (banana fragrance provided near 100% yield after 24 hours using 10% biocatalyst loading (w/w in a fluidized bed reactor, allowing recycling of the biocatalyst up to five times. These results show promising potential for an industrial approach aimed at the biosynthesis of short-chain esters, namely for natural flavor and fragrance production in micro-aqueous media.

  6. Simultaneous microwave extraction and synthesis of fatty acid methyl ester from the oleaginous yeast Rhodotorula glutinis

    Microbial lipids have the potential to substantially reduce the use of liquid fossil fuels, though one obstacle is the energy costs associated with the extraction and subsequent conversion into a biofuel. Here we report a one-step method to produce FAME (fatty acid methyl esters) from Rhodotorula glutinis by combining lipid extraction in a microwave reactor with acid-catalysed transesterification. The microwave did not alter the FAME profile and over 99% of the lipid was esterified when using 25 wt% H2SO4 over 20 min at 120 °C. On using higher loadings of catalyst, similar yields were achieved over 30 s. Equivalent amounts of FAME were recovered in 30 s using this method as with a 4 h Soxhlet extraction, run with the same solvent system. When water was present at less than a 1:1 ratio with methanol, the main product was FAME, above this the major products were FFA (free fatty acids). Under the best conditions, the energy required for the microwave was less than 20% of the energy content of the biodiesel produced. Increasing the temperature did not change the EROI (energy return on investment) substantially; however, longer reaction times used an equivalent amount of energy to the total energy content of the biodiesel. - Highlights: • The extraction and transesterification of yeast lipid were achieved using a microwave reactor. • The lipid was extracted from Rhodotorula glutinis within 30 s under all conditions. • Addition of 25 wt% H2SO4 catalyst converted 95% glycerides to FAME over 5 min. • Water could be tolerated up to 25 wt% without high FFA production. • The temperature of the microwave had less impact on EROI than the length of extraction

  7. Fatty acid esters-based composite phase change materials for thermal energy storage in buildings

    In this study, fatty acid esters-based composite phase change materials (PCMs) for thermal energy storage were prepared by blending erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) with diatomite and expanded perlite (EP). The maximum incorporation percentage for ETP and ETS into diatomite and EP was found to be 57 wt% and 62 wt%, respectively without melted PCM seepage from the composites. The morphologies and compatibilities of the composite PCMs were structurally characterized using scanning electron microscope (SEM) and Fourier transformation infrared (FT–IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by differential scanning calorimetry (DSC) analysis. The DSC analyses results indicated that the composite PCMs were good candidates for building applications in terms of their large latent heat values and suitable phase change temperatures. The thermal cycling test including 1000 melting and freezing cycling showed that composite PCMs had good thermal reliability and chemical stability. TG analysis revealed that the composite PCMs had good thermal durability above their working temperature ranges. Moreover, in order to improve the thermal conductivity of the composite PCMs, the expanded graphite (EG) was added to them at different mass fractions (2%, 5%, and 10%). The best results were obtained for the composite PCMs including 5wt% EG content in terms of the increase in thermal conductivity values and the decrease amount in latent heat capacity. The improvement in thermal conductivity values of ETP/Diatomite, ETS/Diatomite, ETP/EP and ETS/EP were found to be about 68%, 57%, 73% and 75%, respectively. Highlights: ► Fatty acid esters-based composite PCMs were prepared by blending ETP and ETS with diatomite and expanded perlite. ► The composite PCMs were characterized by using SEM, FT–IR, DSC and TG analysis methods. ► The DSC results indicated that the composites PCMs had good thermal

  8. The synthesis of astaxanthin esters,independent of the formation of cysts,highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

    2008-01-01

    The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. pluvialis would be a good resource of valuable fatty acids.

  9. Digital Content Strategies

    Daniel Halbheer; Florian Stahl; Oded Koenigsberg; Donald R. Lehmann

    2013-01-01

    This paper studies content strategies for online publishers of digital information goods. It examines sampling strategies and compares their performance to paid content and free content strategies. A sampling strategy, where some of the content is offered for free and consumers are charged for access to the rest, is known as a "metered model" in the newspaper industry. We analyze optimal decisions concerning the size of the sample and the price of the paid content when sampling serves the dua...

  10. Optimal Use of Plant Stanol Ester in the Management of Hypercholesterolemia

    Susanna Rosin

    2015-01-01

    Full Text Available Plant stanol ester is a natural compound which is used as a cholesterol-lowering ingredient in functional foods and food supplements. The safety and efficacy of plant stanol ester have been confirmed in more than 70 published clinical studies and the ingredient is a well-established and widely recommended dietary measure to reduce serum cholesterol. Daily intake of 2 g plant stanols as plant stanol ester lowers LDL-cholesterol by 10%, on average. In Europe, foods with added plant stanol ester have been on the market for 20 years, and today such products are also available in many Asian and American countries. Despite the well-documented efficacy, the full potential in cholesterol reduction may not be reached if plant stanol ester is not used according to recommendations. This review therefore concentrates on the optimal use of plant stanol ester as part of dietary management of hypercholesterolemia. For optimal cholesterol lowering aiming at a lower risk of cardiovascular disease, plant stanol ester should be used daily, in sufficient amounts, with a meal and in combination with other recommended dietary changes.

  11. Synthesis and Properties of Dendritic Long-Chain Esters as Crude Oil Flow Improver Additives

    Li Cuiqin; Sun Peng; Shi Weiguang; Wang Jun

    2016-01-01

    The efifciencies of 6 kinds of macromolecules with dendritic structure in improving the lfow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl long-chain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efifciencies of dendritic long-chain esters were not only inlfuenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efifciencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efifciencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil.

  12. Analysis of alcohols, as dimethylglycine esters, by electrospray ionization tandem mass spectrometry.

    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

  13. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    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

  14. Protective effects of glutathione isopropyl ester on the sensitivity of cultured cells to UVB irradiation

    The effect of glutathione (GSH) isopropyl ester on cellular sensitivity to UVB irradiation was investigated in HeLaS3 cells. Pretreatment with 0.1-0.5 mM GSH isopropyl ester for 4h significantly inhibited the decrease of thymidine (TdR) incorporation caused by UVB irradiation at a dose of 500 J/m2, whereas pretreatment with a high dose (1 mM) had no effect. The colony formation ability of the pretreated cells (0.3 mM) was significantly better than that of cells that received irradiation only. When the cells were treated with GSH isopropyl ester, their intracellular GSH level increased dose-dependently over a 4h period, suggesting that GSH isopropyl ester was transported into the cells and there converted to GSH. Within 2 min of exposure, the intracellular GSH level depleted rapidly to about 75% of that in non-irradiated normal cells. In contrast, the GSH level in cells pretreated with 0.3 mM GSH isopropyl ester was maintained at the same level as that in normal cells, indicating that the maintenance of intracellular GSH level is due to converted GSH from GSH isopropyl ester. These results clearly show that intracellular GSH is involved in cell protection against photodamage, and that GSH isopropyl ester is a useful antioxidant for protection against photooxidative injury. (author)

  15. A comparison of chemiluminescent acridinium dimethylphenyl ester labels with different conjugation sites.

    Natrajan, Anand; Wen, David

    2015-03-01

    Chemiluminescent acridinium dimethylphenyl esters are highly sensitive labels that are used in automated assays for clinical diagnosis. Light emission from these labels and their conjugates is triggered by treatment with alkaline peroxide. Conjugation of acridinium ester labels is normally done at the phenol. During the chemiluminescent reaction of these acridinium esters, the phenolic ester is cleaved and the light emitting acridone moiety is liberated from its conjugate partner. In the current study, we report the synthesis of three new acridinium esters with conjugation sites at the acridinium nitrogen and compare their properties with that of a conventional acridinium ester with a conjugation site at the phenol. Our study is the first that provides a direct comparison of the emissive properties of acridinium dimethylphenyl esters (free labels and protein conjugates) with different conjugation sites, one where the light emitting acridone remains attached to its conjugate partner versus conventional labeling which results in cleavage of the acridone from the conjugate. Our results indicate that the conjugation at the acridinium nitrogen, which also alters how the acridinium ring and phenol are oriented with respect to the protein surface, has a minimal impact on emission kinetics and emission spectra. However, this mode of conjugation to three different proteins led to a significant increase in light yield which should be useful for improving the assay sensitivity. PMID:25581208

  16. Synthesis and characterization of vegetable oil derived esters: evaluation for their diesel additive properties.

    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

  17. Wide Range of Biotin (Vitamin H) Content in Foodstuffs and Powdered Milks as Assessed by High-performance Affinity Chromatography

    Hayakawa, Kou; Katsumata, Noriyuki; Abe, Kiyomi; Hirano, Masahiko; Yoshikawa, Kazuyuki; Ogata, Tsutomu; Horikawa, Reiko; Nagamine, Takeaki

    2009-01-01

    The biotin (vitamin H) contents of various foodstuffs were determined by using a newly developed high-performance affinity chromatography with a trypsin-treated avidin-bound column. Biotin was derivatized with 9-anthryldiazomethane (ADAM) to fluorescent biotin-ADAM ester. A wide range of biotin contents were found in various foodstuffs depending upon the species (strain), season, organ (of plants and animals), geography, freshness, preparation method and storage method. Among the foodstuffs a...

  18. Lipid content and fatty acid composition of Mediterranean macro-algae as dynamic factors for biodiesel production

    Dahlia M. El Maghraby; Eman M. Fakhry

    2015-01-01

    Using the total lipid contents and fatty acid profiles, the marine macro-algae Jania rubens (Rhodophyceae), Ulva linza (Chlorophyceae) and Padina pavonica (Phaeophyceae) were evaluated for biodiesel production during the spring, summer and autumn. Seawater parameters such as pH, salinity and temperature were measured. The total lipid content varied from 1.56% (J. rubens) to 4.14% (U. linza) of dry weight, with the highest values occurring in spring. The fatty acid methyl ester profiles were a...

  19. Synthesis and cytotoxicity of boronated fatty esters for BNCT of cervix cancer

    Esterification reactions of o-carboranic acid with six fatty alcohols, palmitoleyl, stearyl, oleyl, elaidyl, linoleyl and linoelaidyl alcohols, proceeded smoothly under nitrogen atmosphere with dimethylamino pyrimidine as a catalyst. The reaction gave the corresponding esters in moderate yields. Most of the synthetic esters are stable at room temperature except the linoleyl carboranate and linoelaidyl carboranate which decomposed within two weeks. The in vitro studies on Hela cells showed relatively low cytotoxic. The IC50 of boronated esters were in range of 36-83 micrograms/cm3. (author)

  20. Diarrhetic shellfish poisoning toxin esters in Danish blue mussels and surf clams

    Jørgensen, Kevin; Scanlon, Sine Hedegaard; Jensen, L.B.

    2005-01-01

    . Samples of Danish surf clams ( Spisola spp.) and blue mussels ( Mytilus edulis) from 1999 - 2004 were analysed by liquid chromatography coupled with tandem mass spectrometry ( LC/ MS/ MS) for the presence of DSP toxin esters. The samples contained only okadaic acid and esters of okadaic acid. The level of...... total okadaic acid equivalents ranged from 224 to 2516 mu g kg (-1) in surf clams. The percentage of okadaic acid esters of the total okadaic acid equivalents ranged from 83 to 98%, mean 95%. The level of total okadaic acid equivalents ranged from 43 to 1631 mu g kg (-1) in blue mussels. The percentage...

  1. Synthesis and Structural Characterization of 1- and 2-Substituted Indazoles: Ester and Carboxylic Acid Derivatives

    Isabel Bento; Teresa Duarte, M.; M. João M. Curto; Inês F. Antunes; Hélène Ramos; Fátima C. Teixeira

    2006-01-01

    A series of indazoles substituted at the N-1 and N-2 positions with ester-containing side chains -(CH2)nCO2R of different lengths (n = 0-6, 9, 10) are described.Nucleophilic substitution reactions on halo esters (X(CH2)nCO2R) by 1H-indazole inalkaline solution lead to mixtures of N-1 and N-2 isomers, in which the N-1 isomerpredominates. Basic hydrolysis of the ester derivatives allowed the synthesis of thecorresponding indazole carboxylic acids. All compounds were fully characterised bymultin...

  2. Study on extraction mechanism of scandium (III) with alkylphosphonic acid monoalkyl ester

    The extraction mechanism of Sc(III)from hydrochloric acid solutions with s-octylphosphonic acid mono-iso-octyl ester (PT-19), iso-propylphosphonic acid mono-(1-hexyl-4-ethyl) octyl ester(PT-2) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(P507)in heptane is investigated. The extraction reaction of Sc(III) expressed by the equations of chemical reactions are given. The equilibrium constants and thermodynamic functions of extraction reactions are calculated. The IR and NMR spectra of the extraction complexes of Sc(III) are discussed as well

  3. [Synthesis and bronchodilator action of 4-(methoxycarbonylalkylsulfinyl)-4-pyrrol carboxylic esters].

    Eiden, F; Grusdt, U

    1989-11-01

    The dihydro-dimethoxyfuran carboxylic ester 3 reacts with different mercaptoalkyl carboxylates to give the carbomethoxyalkylthio-tetrahydrofuran carboxylic esters 4. Methanol elimination of 4 yields the dihydrofuran derivatives 5. 4 and 5 can be oxidized to afford the sulfoxides 6 and the sulfones 7, respectively. 4 reacts with primary amines to give the title compounds 8. Derivatives of 8 can be cyclized to afford the thienopyrroles 11 and 12 as well as the thienopyranopyrrole 14. The mercaptopyrrole carboxylic ester 10 is obtained from 8f by elimination of propenic acid. 8e shows bronchodilatoric activity in low concentration. PMID:2624526

  4. Application of Factorial Design of Experiments for the Continuous Hydrogenation of Enriched Castor Oil Methyl Esters

    Tulasi Sri Venkata Ramana Neeharika; Karna Narayana Prasanna Rani; Kasturi Venkata Sesha Adinarayana Rao; Thella Prathap Kumar; Rachapudi Badari Narayana Prasad

    2013-01-01

    Castor oil methyl esters contains nearly 90% ricinoleic acid (12-hydroxy-cis-9-octadecenoic acid). Hydrogen-ated castor oil methyl esters finds several applications in coating, lubricants formulations and pharmaceu-tical areas. The present study reports a fast, simple, efficient and continuous hydrogenation of enriched castor oil methyl ester (ECME) using 10% Pd/C catalyst at different pressures and temperatures. The range of process conditions for this study varied from 30-60 °C, 5-15 bar wi...

  5. Statistical Evaluation of HTS Assays for Enzymatic Hydrolysis of β-Keto Esters

    Buß, O.; Jager, S.; S-M Dold; S. Zimmermann; Hamacher, K.; Schmitz, K.; J Rudat

    2016-01-01

    β-keto esters are used as precursors for the synthesis of β-amino acids, which are building blocks for some classes of pharmaceuticals. Here we describe the comparison of screening procedures for hydrolases to be used for the hydrolysis of β-keto esters, the first step in the preparation of β-amino acids. Two of the tested high throughput screening (HTS) assays depend on coupled enzymatic reactions which detect the alcohol released during ester hydrolysis by luminescence or absorption. The th...

  6. Synthesis and Biological Activity of New Pyrethroid Acid Oxime-esters Containing Pyrazole Ring

    MA Jun-an; HUANG Run-qiu; FENG Lei; SONG Jian; QIU De-wen

    2003-01-01

    A series of compounds containing oxime-ester linkage and pyrazole ring(in place of the ester linkage and the alcohol moiety in pyrethroid ester) was designed and synthesized. The structures of all the compounds prepared were confirmed by 1H NMR and MS spectroscopy as well as elemental analyses. The bioassay data of those compounds against tobacco mosaic virus(TMV), cucumber mosaic virus(CMV), potato virus X(PVX) and potato virus Y(PVY) were presented. Among them compound 6i was found to possess significant plant antiviral activities. But all the compounds showed low insecticidal and acaricidal activities.

  7. Molecular Dynamics Simulation of Palmitate Ester Self-Assembly with Diclofenac

    Abu Bakar Salleh

    2012-07-01

    Full Text Available Palm oil-based esters (POEs are unsaturated and non-ionic esters with a great potential to act as chemical penetration enhancers and drug carriers for transdermal drug nano-delivery. A ratio of palmitate ester and nonionic Tween80 with and without diclofenac acid was chosen from an experimentally determined phase diagram. Molecular dynamics simulations were performed for selected compositions over a period of 15 ns. Both micelles showed a prolate-like shape, while adding the drug produced a more compact micellar structure. Our results proposed that the drug could behave as a co-surfactant in our simulated model.

  8. Catalytic synthesis of butyric esters with TiSiW12O40/TiO2

    2003-01-01

    The catalytic activities of TiSiW12O40/TiO2 in synthesizing ethyl ester, propyl ester, n-butyl ester, and amyl esterwere reported. It was demonstrated that TiSiW12O40/TiO2is an excellent catalyst. Various factors concemed with esterifica-tion were investigated. The optimum conditions were found: the mole ratio of alcohol to acid is 1.3:1, the mass ratio ofcatalyst to reactants is 1.5%, and the reaction time is 1.0 h. Under the optimum conditions, the yields are 88.0% for ethylester, 94.5% for propyl ester, 98.6% for n-butyl ester, 99.1% for n-amyl ester, and 96.7% for iso-amyl ester, respectively.

  9. Coupling of activated esters to gramines in the presence of ethyl propiolate under mild conditions

    Jones, David T.; Artman, Gerald D.; Williams, Robert M.

    2007-01-01

    The coupling of activated esters to gramine derivatives is described using ethyl propiolate. A series of substrates have been prepared using these mild conditions to provide a scope and limitations for this methodology.

  10. Enantiospecific sp2-sp3 coupling of secondary and tertiary boronic esters

    Bonet, Amadeu; Odachowski, Marcin; Leonori, Daniele; Essafi, Stephanie; Aggarwal, Varinder K.

    2014-07-01

    The cross-coupling of boronic acids and related derivatives with sp2 electrophiles (the Suzuki-Miyaura reaction) is one of the most powerful C-C bond formation reactions in synthesis, with applications that span pharmaceuticals, agrochemicals and high-tech materials. Despite the breadth of its utility, the scope of this Nobel prize-winning reaction is rather limited when applied to aliphatic boronic esters. Primary organoboron reagents work well, but secondary and tertiary boronic esters do not (apart from a few specific and isolated examples). Through an alternative strategy, which does not involve using transition metals, we have discovered that enantioenriched secondary and tertiary boronic esters can be coupled to electron-rich aromatics with essentially complete enantiospecificity. As the enantioenriched boronic esters are easily accessible, this reaction should find considerable application, particularly in the pharmaceutical industry where there is growing awareness of the importance of, and greater clinical success in, creating biomolecules with three-dimensional architectures.

  11. Neutral-lipid transfers and cholesteryl ester transfer protein in hemodialyzed patients.

    Reade, V; Mezdour, H; Reade, R; Kandoussi, M; Dracon, M; Fruchart, J C; Cachera, C

    1996-01-01

    Abnormalities in cholesteryl ester transfers may play a role in the development of atherosclerosis observed in patients with end-stage renal failure treated by chronic hemodialysis. Net neutral-lipid transfers and cholesteryl ester transfer protein activity and mass were investigated in 20 hemodialyzed patients, arbitrarily divided into two groups based on fasting triglyceride levels, and compared to triglyceride-matched control groups. In the hypertriglyceridemic subjects (plasma triglyceride values > 150 mg/dl), high-density lipoprotein cholesterol was decreased, and the net cholesteryl ester transfer rates were significantly higher than the rates in normolipidemic subjects. The comparison of subjects matched for plasma triglyceride and cholesterol levels showed no significant difference in cholesteryl ester or triglyceride transfer rates between patients and controls. Our results suggest that normal or elevated net neutral-lipid transfers are not related to the renal status of the subjects, but rather to their plasma triglyceride levels. PMID:8886176

  12. Phthalate Esters and Reproductive Toxicity** Presentation requested by State of Mass Use Reductions Committee-TURI

    Phthalate esters and reproductive toxicity the presentation described the uses of phthalates, the toxicity to mammals with a focus on reproductive toxicity and the potency of these chemicals to disrupt mammalian reproductive development in utero

  13. Ester Tuiksoo : Saksamaa on Eestile biomassi ja GMO vallas eeskujuks / Ain Lember

    Lember, Ain

    2006-01-01

    Põllumajandusminister Ester Tuiksoo ja abiminister Rain Vändre kohtusid Kielis Schleswig-Holsteini liidumaa ministri dr. Christian von Boetticheriga, peateemadeks abi biomassi ja geneetiliselt muundatud kultuurtaimede kooseksisteerimise vallas

  14. Efficient Syntheses of 2-Substituted Benzimidazoles and Benzoxazoles from β-Keto Esters

    XIAO Li-wei; ZHANG Min; SUN Wen-hua

    2011-01-01

    An efficient synthetic method was developed to synthesize 2-substituted benzimidazoles and benzoxazoles withβ-keto esters as starting materials under mild reaction conditions, during which other functional groups are bearable from reactants to products.

  15. RELATIONSHIP OF NEUROPATHY TARGET ESTERASE INHIBITION TO NEUROPATHOLOGY AND ATAXIA IN HENS GIVEN ORGANOPHOSPHORUS ESTERS

    Adult WhiteLeghorn hens were acutely exposed to 3 dosages of the following organophosphorus esters: mipafox, tri-ortho-tolyl phosphate (TOTP), penyl saligenin phosphate, diisppropylophosphoro-fluoridate (DFP), malathion and dichlorvos. europathy target esterase (NTE) activity was...

  16. Radiosensitivity and hydroxyl radical reactivity of phosphate esters as measured by radiation-induced dephosphorylation

    The yields of inorganic phosphate from irradiated phosphate esters of biological interest have been measured in the presence of various free-radical scavengers. These studies indicated that hydroxyl radical attack on the phosphate esters accounts for most of this damage. Competition kinetics using different hydroxyl radical scavengers whose reactivities are known to have been used to estimate the rate-constants for the overall hydroxyl radical reactivities of the phosphate esters. The extent of hydroxyl-radical-induced dephosphorylation was very low for nucleotide derivatives, but high for some sugar and glycerol phosphates, reflecting the probability of hydroxyl radical abstraction at the α or β carbon atoms adjacent to the phosphate ester linkage. The hydroxyl radical reactivities of nucleotides, coenzymes, sugar phosphates and phospholipid components were all high (1 to 10x109M-1sec-1), indicating the importance of hydroxyl radical attack in the inactivation of these components in living cells, although not necessarily by dephosphorylation. (author)

  17. Synthesis and evaluation of thalidomide and phthalimide esters as antitumor agents

    Zahran, Magdy A H; Abdin, Yasmin G.; Osman, Amany M A;

    2014-01-01

    A series of thalidomide and phthalimide ester analogs were efficiently synthesized from N-chloromethylthalidomide, N-chloromethylphthalimide, and N-(2-bromoethyl)phthalimide derivatives with various biologically important carboxylic acids. The synthesized compounds were purified and characterized...

  18. The oxidative stability of rapeseed oil methyl and ethyl esters - environment friendly alternative fuel

    The oxidative stability of rapeseed oil and bio diesel fuel RME and REE, produced from it, has been determined. The addition of antioxidant BHT essentially prolongs the utility term of oil and its esters. (authors)

  19. Nooruslikud juubilarid: fotokelder Lee 20 ja fotomuuseum 30 / Mall Parmas, Betty Ester-Väljaots

    Parmas, Mall

    2013-01-01

    Peeter Toominga algatusel 1992. aastal asutatud Lee fotokeldrist. Loetletud fotomuuseumis oma töid eksponeerinud fotograafid. Ülevaatenäitus "Lee fotokelder 20" 17. jaanuarist 20. märtsini, koostaja Betty Ester-Väljaots

  20. New composites of betulin esters with arabinogalactan as highly potent anti-cancer agents.

    Shakhtshneider, T P; Kuznetsova, S A; Zamay, A S; Zamay, T N; Spivak, E A; Mikhailenko, M A; Malyar, Yu N; Kuznetsov, B N; Chesnokov, N V; Boldyrev, V V

    2016-06-01

    Betulin and its esters are the natural compounds with high in vitro cytotoxicity toward many cancer cells. However, the poor water solubility of these compounds has limited their applications. We prepared new composites of betulin esters using two methods, namely ball-milling of the mixtures of betulin esters with arabinogalactan and preparation of thin films of these mixtures by evaporating the aqueous solutions. These composites revealed higher water solubility as compared with the initial substances without losing the structural integrity and functionality. As a result, the new composites have shown much higher inhibitory effects against different cancer cell lines such as Ehrlich ascites carcinoma cells and lung carcinoma cells (A549) in comparison with the initial substances. The cell viability studies based on Annexin V and Propidium iodide probes have confirmed the high proapoptotic effect of betulin ester derivatives against cancer cells. PMID:26165861