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Sample records for adipate ester contents

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

    DEFF Research Database (Denmark)

    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......-Raman Spectroscopy, Appl. Spectrosc. 58 (4) (2004) 410–413]—on detection of the presence of phthalate esters in PVC by FT-Raman spectroscopy — is here extended to the similar case of adipate esters (AEs) in samples of soft poly vinyl chloride plastics. Spectra of a range of adipate ester plasticizers (11 AEs......) in pure form are reported. We studied if qualitative and quantitative determination of the adipate ester content would be possible based on the use of proper reference samples. It was found that AEs as a group cannot be definitively identified by their characteristic Raman bands because other aliphatic...

  2. Analysis of Adipate Ester Contents in PVC Plastics

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    -ethylhexyl adipate or DEHA [103-23-1], also known as Adimoll® or di-octyl adipate, DOA, see Fig. 1. A widely used plasticizer in food (cling) films is DEHA, often in combination with polymers, epoxidized soya-bean oil, etcetera. DEHA also occurs in children toys. We have previously shown that the presence...

  3. Gas-liquid chromatographic determination of adipate content of acetylated di-starch adipate.

    Science.gov (United States)

    Mitchell, G A; Vanderbist, M J; Meert, F F

    1982-03-01

    A gas-liquid chromatographic method is described for rapid, quantitative determination of adipate content of acetylated di-starch adipate. The adipate group is very labile and, under mild alkaline conditions at ambient temperature, is easily hydrolyzed from the starch. Free adipic acid is formed by acidification of the solution with HCl, and then extracted with ethyl acetate. Ethyl acetate is removed under vacuum distillation, and a silyl derivative of the adipic acid is formed. Glutaric acid internal standard is introduced into the original starch sample before hydrolysis. An aliquot of the silylated solution is injected into a gas chromatograph fitted with a column having silicone oil as the active phase. A flame ionization detector is also incorporated. Results correlate well the amount of adipylating reagent used. No adipic acid is detectable when a hydrolyzed, extracted sample of acetylated di-starch adipate is subjected to a second extraction. Recovery levels of adipic acid, from starches fortified with 100-500 ppm, are in the range of 97-102.5%.

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

    Science.gov (United States)

    2011-02-11

    ... AGENCY 40 CFR Part 180 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4- Butanediol, Adipic... from the requirement of a tolerance for residues of 1,4-benzenedicarboxylic acid, dimethyl ester... residues of 1,4-benzenedicarboxylic acid, dimethyl ester, polymer with 1,4-butanediol, adipic acid,...

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Effect of Alcohol Structure on the Optimum Condition for Novozym 435-Catalyzed Synthesis of Adipate Esters

    Directory of Open Access Journals (Sweden)

    Mohd Basyaruddin Abdul Rahman

    2011-01-01

    Full Text Available Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol. Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning important reaction parameters which include time, temperature, substrate molar ratio, and amount of enzyme. Reactions under optimized conditions has yielded a high percentage of esterification (>96% for n-butanol, iso-butanol, and sec-butanol, indicating that extent of esterification is independent of the alcohol structure for primary and secondary alcohols at the optimum conditions. Minimum reaction time (135 min for achieving maximum ester yield was obtained for iso-butanol. The required time for attaining maximum yield and also the initial rates in the synthesis of di-n-butyl and di-sec-butyl adipate were nearly the same. Immobilized Candida antarctica lipase B was also capable of esterifying tert-butanol with a maximum yield of 39.1%. The enzyme is highly efficient biocatalyst for the synthesis of adipate esters by offering a simple production process and a high esterification yield.

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

    DEFF Research Database (Denmark)

    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...

  8. Effects of perinatal exposure to phthalate/adipate esters on hypothalamic gene expression and sexual behavior in rats.

    Science.gov (United States)

    Lee, Hwi-Cheul; Yamanouchi, Keitaro; Nishihara, Masugi

    2006-06-01

    Our previous research has identified the granulin (grn) and p130 genes as sex steroid-regulated genes in the neonatal rat hypothalamus that might be involved in sexual differentiation of the brain. Since phthalate/adipate esters such as di-n-butyl phthalate (DBP), diisononyl phthalate (DINP), and di-2-ethylhexyl adipate (DEHA) are suspected to interfere with the endocrine system as environmental endocrine disruptors having estrogenic or antiandrogenic properties, these chemicals may affect sexual differentiation of the brain. The present study assessed the effects of perinatal exposure to DBP, DINP, and DEHA on grn and p130 mRNA expressions in the hypothalamus on postnatal day (PND) 7 and sexual behaviors after maturation in rats. Maternal rats were given a phytoestrogen-free diet containing different doses of DBP (20, 200, 2,000, and 10,000 ppm), DINP (40, 400, 4,000, and 20,000 ppm) and DEHA (480, 2,400, and 12,000 ppm) from gestational day 15 to the day of weaning (PND 21). DBP and DINP exposure during the perinatal period resulted in an increase in hypothalamic grn and p130 mRNA levels in females and males, respectively, but DEHA exposure decreased expression levels of grn in males and p130 in females, although the effects were not dose-dependent. After maturation, male rats that were exposed to several doses of DBP, DINP, and DEHA displayed decreased copulatory behavior. The lordosis quotient was decreased in females perinatally exposed to DBP, DINP, and DEHA at all the doses used. On the other hand, serum levels of LH and FSH in both sexes and the estrous cycles in females were not affected by the treatments. These results suggest that inappropriate expression of grn and/or p130 genes in the brains of male and female neonatal rats by perinatal exposure to these chemicals may exert permanent effects on the hypothalamus, thereby decreasing sexual behavior after maturation.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Toxicity of adipic acid.

    Science.gov (United States)

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests.

  11. [Biosynthesis of adipic acid].

    Science.gov (United States)

    Han, Li; Chen, Wujiu; Yuan, Fei; Zhang, Yuanyuan; Wang, Qinhong; Ma, Yanhe

    2013-10-01

    Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.

  12. 合成三羟甲基丙烷庚酸己二酸混合酯热力学分析%Thermodynamics Analysis on Synthesis of Trimethylolpropane, Heptanoic Acid and Adipic Acid Mixed Ester

    Institute of Scientific and Technical Information of China (English)

    马楷; 李秀涛; 赵玉贞; 皞刘月

    2015-01-01

    The group contribution method was applied to estimate the enthalpy and entropy of trimethylolpropane, heptanoic acid,adipic acid and trimethylolpropaneheptanoate acid and adipic acid mixed ester at 298.15 K. The functional correlations between the heat capacity of these organic compounds and temperature were established. And the enthalpy changes, entropy changes and Gibbs free energy changes as well as the equilibrium constants of the one-step, two-step esterification and transesterification of trimethylolpropane, adipic acid and heptanoic acid were calculated under different temperatures. The results show that the one-step esterification method can meet the demand even if heptoic acid is excess, and the one-step esterification method is the best in the aspect of thermodynamics.%采用基团贡献法估算了反应体系中三羟甲基丙烷酯、庚酸、己二酸和三羟甲基丙烷混合酯在298.15 K标准状态下的生成焓和标准熵,计算了不同温度条件下一步法、两步法酯化法和酯交换法合成三羟甲基丙烷庚酸、己二酸混合酯的焓变、Gibbs 自由能和标准平衡常数。通过对反应体系的热力学分析发现,一步法、两步法和酯交换三种方法均可以得到三羟甲基丙烷庚酸、己二酸混合酯。采用一步法直接酯化合成即使在庚酸过量的情况下仍然可以满足要求,并且热力学上更有优势,并对反应进行了验证,这些计算为一步法合成混合酯的工业生产提供了理论依据。

  13. Reduction of phorbol ester content in jatropha cake using high energy gamma radiation

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    Runumi Gogoi

    2014-07-01

    Full Text Available In this paper, an attempt has been made to remove phorbol ester present in jatropha cake by exposing it to gamma radiation. A sensitizer was also used to accelerate the degradation of phorbol esters. The phorbol ester content in the cake was estimated by high performance liquid chromatography (HPLC. It was observed that gamma irradiation of the jatropha seed cake was effective in reducing the phorbol ester content. Originally, the phorbol ester content in the cake was found as 0.29 mg/g, which on exposure to radiation was reduced by 33.4% and 96% with radiation dose of 30 and 125 kGy respectively. The presence of a sensitizer was found to enhances the susceptibility of phorbol esters degradation by oxidative degradation on exposure to ionizing radiation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruno V.M.; Silva, Aline S. [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil); Melo, Gabriela F.S.; Vasconscellos, Luana M.R. [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, Sao Paulo State University (UNESP), Av. Engenheiro Francisco Jose Longo 777, Sao Jose dos Campos, Sao Paulo (Brazil); Marciano, Fernanda R. [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil); Lobo, Anderson O., E-mail: aolobo@pq.cnpq.br [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil)

    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) (0.1–0.5 wt.%) 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 3.6 MPa with addition of 0.5 wt.% 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. - Highlights: • Nanocomposites from PBAT and superhydrophilic MWCNT (sMWCNT) were successfully prepared by electrospinning

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

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2006-01-01

    -ethylhexyl adipate or DEHA [103-23-1], also known as Adimoll or di-octyl adipate, DOA. A widely used plasticizer in food (cling) films is DEHA, often in combination with polymers, epoxidized soya-bean oil, etcetera. DEHA also occurs in children toys. We have previously shown that the presence of phthalate...

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

    DEFF Research Database (Denmark)

    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...... 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....

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

    DEFF Research Database (Denmark)

    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...... 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....

  18. 21 CFR 582.1009 - Adipic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Adipic acid. 582.1009 Section 582.1009 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1009 Adipic acid. (a) Product. Adipic acid. (b) [Reserved] (c) Limitations, restrictions, or...

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

    Science.gov (United States)

    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.

  20. Adipic Acid: Vigorous Import Growth

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Adipic acid is mainly used to manufacture nylon 6,6, plasticizers, grease, polyurethane etc. There are three major commercial production processes: cyclohexane process, cyclohexanol process, butadiene carbonylation process, and the air oxidation of cyclohexane process constitute 93% of the total.

  1. 21 CFR 184.1009 - Adipic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Adipic acid. 184.1009 Section 184.1009 Food and... Substances Affirmed as GRAS § 184.1009 Adipic acid. (a) Adipic acid (C6H10O4, CAS Reg. No. 00124-04-9) is also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid oxidation...

  2. How 'ground-picked' olive fruits affect virgin olive oil ethanol content, ethyl esters and quality.

    Science.gov (United States)

    Beltran, Gabriel; Sánchez, Raquel; Sánchez-Ortiz, Araceli; Aguilera, Maria P; Bejaoui, Mohamed A; Jimenez, Antonio

    2016-08-01

    Olives dropped on the ground naturally sometimes are not separated from those fresh and healthy collected from the tree for harvest and processing. In this work we compared the quality, ethanol content and bioactive components of virgin olive oils from ground-picked olives, tree-picked fruits and their mixture. Ground-picked olives produced 'Lampante' virgin olive oils; these are of a lower quality category, because of important alterations in chemical and sensory characteristics. Ethyl esters showed the highest values, although under the regulated limit. The mixture of ground and tree-picked olives gave oils classified as 'virgin' because of sensory defects, although the quality parameters did not exceed the limits for the 'extra' category. Ethanol content showed a significant increase in the oils from ground- picked olives and their mixture with respect to those from tree-picked fruits. Furthermore, bioactive compounds showed a significant decrease as fruit quality was poorer. Ground-picked olives must be harvested and processed separately since they produce low-quality virgin olive oils with sensory defects and lower concentrations of bioactive compounds. The higher acidity and ethanol concentration observed in oils from ground-picked fruits or their mixture may help ethyl ester synthesis during storage. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Effect of milling on DSC thermogram of excipient adipic acid.

    Science.gov (United States)

    Ng, Wai Kiong; Kwek, Jin Wang; Yuen, Aaron; Tan, Chin Lee; Tan, Reginald

    2010-03-01

    The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential scanning calorimetry (DSC) measured fusion enthalpy (Delta(fus)H) and melting point (T(m)) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after milling, the values of Delta(fus)H and T(m) were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results.

  5. Properties of collagen gels cross-linked by N-hydroxysuccinimide activated adipic acid deriviate.

    Science.gov (United States)

    Duan, Lian; Liu, Wentao; Tian, Zhenhua; Li, Conghu; Li, Guoying

    2014-08-01

    In order to improve the properties of collagen gel, N-hydroxysuccinimide activated adipic acid derivative (NHS-AA) was introduced into the formation of collagen fibrils. NHS-AA with different [NHS-AA]/[NH2] ratios (0.1-1.5, calculated by [ester group] of NHS-AA and [NH2] of lysine and hydroxylysine residues of collagen) was added after, simultaneously with or before the formation of collagen fibrils (abbreviated CAF, CSF and CBF, respectively) to obtain different collagen gels. With the same dose of NHS-AA, the cross-linking degree for CAF was lower than those for CSF and CBF. The formation of collagen fibrils was restrained by NHS-AA for CSF and CBF while that for CAF was unaffected. When the dose of NHS-AA increased from 0.1 to 1.5, the water contents of CSF and CBF increased while that of CAF had no obvious change. With lower dose of NHS-AA (0.1), CAF possessed higher value of G' (87.3Pa) and the best thermal stability (47.6°C). As the ratio of [NHS-AA]/[NH2] increased to 1.5, CSF had the maximum value of G' (288.8Pa) and CAF had the best thermal stability (52.9°C). These results showed collagen gels with different properties could be prepared by adding NHS-AA with different adding sequence and dose.

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

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    ) phthalate, DEHP (also referred to as dioctyl phthalate - DOP) and many products containing this phthalate are in common use. We measured the Raman spectra of 21 different phthalate esters and found six common Raman bands, present for all. These bands are accordingly assigned to the dicarbonyl ortho......-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...

  7. Determination of Alkyl Esters Content in PDO Extra Virgin Olive Oils from Sicily

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    Rosaria Costa

    2017-01-01

    Full Text Available The quality parameter of alkyl esters of fatty acids was checked in a variety of Italian olive oil samples. In particular, 34 samples of extra virgin olive oils (EVOOs from South Italy (Sicilian orchards, produced in the years 2014-2015, have been subjected to the analytical protocol dictated by the European Union for the determination of alkyl esters, as an indicator of oil’s quality. All the samples analyzed resulted to be well below the limit set by EU Directive. Besides recently produced EVOOs, a set of very aged oils, produced in the years 1996–2000, were analyzed as well. The main finding was that alkyl esters increased in correspondence with deterioration processes.

  8. Characterization of Lipids and Fatty Acid Methyl Ester Contents in Leaves and Roots of Crocus vallicola

    OpenAIRE

    YAYLI, Nurettin; KIRAN, Zerrin; SEYMEN, Hasan; GENÇ, Hasan

    2001-01-01

    The chemical composition of the fatty acids methyl esters (FAMEs) and other lipids in leaves and roots of Crocusvallicola were analyzed by gas chromatography-mass spectrometry(GC-MS). In this work, twenty-eight compounds, including 22 FAMEs, 1 aldehyde, 3 hydrocarbons (substitute alkane and alkene), 2 alcohols in the leaves and twenty-one compounds (17 FAMEs, 1 anhydride, 1 substitute alcohol, 1 ketone, 1 substitute amide) in the roots were identified by GC-MS from C. vallicola. Th...

  9. The Effect of Type of Oil and Degree of Degradation on Glycidyl Esters Content During the Frying of French Fries.

    Science.gov (United States)

    Aniołowska, Magda; Kita, Agnieszka

    The aim of the study was to determine the effect of oil degradation on the content of glycidyl esters (GEs) in oils used for the frying of French fries. As frying media, refined oils such as rapeseed, palm, palm olein and blend were used. French fries were fried for 40 h in oils heated to 180 °C in 30-min cycles. After every 8 h of frying, fresh oil and samples were analyzed for acid and anisidine values, color, refractive index, fatty acid composition, and content and composition of the polar fraction. GEs were determined by LC-MS. Hydrolysis and polymerization occurred most intensively in palm olein, while oxidation was reported for rapeseed oil. The degradation of oil caused increased changes in the RI of frying oils. Losses of mono- and polyunsaturated fatty acids were observed in all samples, with the largest share in blend. The highest content of GE found in fresh oil was in palm olein (25 mg kg(-1)) and the lowest content of GE was found in rapeseed oil (0.8 mg kg(-1)). The palm oil, palm olein and blend were dominated by GEs of palmitic and oleic acids, while rapeseed oil was dominated by GE of oleic acid. With increasing frying time, the content of GEs decreased with losses from 47 % in rapeseed oil to 78 % in palm oil after finishing frying.

  10. Incorporation of different crystallizable amide blocks in segmented poly(ester amide)s

    NARCIS (Netherlands)

    Lips, P.A.M.; Broos, R.; Heeringen, van M.J.M.; Dijkstra, P.J.; Feijen, J.

    2005-01-01

    High molecular weight segmented poly(ester amide)s were prepared by melt polycondensation of dimethyl adipate, 1,4-butanediol and a symmetrical bisamide-diol based on ε-caprolactone and 1,2-diaminoethane or 1,4-diaminobutane. FT-IR and WAXD analysis revealed that segmented poly(ester amide)s based

  11. 21 CFR 178.3690 - Pentaerythritol adipate-stearate.

    Science.gov (United States)

    2010-04-01

    ... adipic acid and stearic acid and its associated fatty acids (chiefly palmitic), with adipic acid comprising 14 percent and stearic acid and its associated acids (chiefly palmitic) comprising 71 percent of...: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (2) Acid...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    S. S. Hings

    2008-03-01

    Full Text Available Slightly soluble atmospherically relevant organic compounds, such as adipic acid, may influence particle CCN activity and therefore cloud formation. 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 and dry adipic acid particles without the need to produce them by atomization of aqueous solutions. The CCN effect of adipic acid coatings on both soluble and insoluble particles has also been studied. 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. Adipic acid particles prepared in a wet state follow the Köhler curve over the full range of particle diameters studied. 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 addition of a hydrophilic soluble compound to dry adipic acid eliminates the effect of particle phase, that is, the effect of the deliquescence barrier to CCN activation. An adipic acid coating on hydrophobic soot yields a CCN active particle. For the relatively small soot particles (dcore=88 and 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.

  15. Development of a vibrofluidized bed and fluid-dynamic study with dry and wet adipic acid

    Directory of Open Access Journals (Sweden)

    Silva-Moris V.A.

    2003-01-01

    Full Text Available The vibrofluidized bed developed in this work, consisting of a transparent plexiglass tube with an inner diameter of 0.1 m and a height of 0.5 m, was designed for the fluidization of adipic acid. The fluidization behavior of dry adipic acid with particle diameters in the range of 75 - 600 mm and a density of 1340kg/m³ was studied using mechanical vibration for different sample loads. Variables studied for the wet material include frequency and amplitude of vibration and moisture content of the particles. On the basis of the quantitative flow curve data and visual observations, it is concluded that the fluid dynamics of the bed with wet sticky particles, both vibrating and not vibrating, is different from that of the bed with dry particles.

  16. Polymerization of Pyrrole and Thiophene on Polyethylene Adipate Electrodes

    OpenAIRE

    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...

  17. Toxicological investigation of di(2-ethylhexyl)adipate in rats

    NARCIS (Netherlands)

    Jansen EHJM; van den Ham WA; de Fluiter P; van Leeuwen FXR

    1993-01-01

    In a study in which male rats have been exposed to 0, 200, 600, 2000, 6000 and 20000 mg di(2-ethylhexyl)adipate (DEHA)/kg diet for 2 weeks, body weight and liver weight and a number of enzyme parameters which are related with peroxisome proliferation (palmitoyl coenzyme-A oxidase (PCO), enoyl coenzy

  18. Effects of pressure and TEGDN content on decomposition reaction mechanism and kinetics of DB gun propellant containing the mixed ester of TEGDN and NG.

    Science.gov (United States)

    Yi, Jian-hua; Zhao, Feng-qi; Xu, Si-yu; Zhang, La-ying; Gao, Hong-xu; Hu, Rong-zu

    2009-06-15

    The effects of pressure and triethyleneglycol dinitrate (TEGDN) content on the decomposition reaction mechanism and kinetics of the double-base (DB) gun propellant composed of mixed ester of TEGDN and nitroglycerin (NG), and nitrocellulose (NC) were investigated by high-pressure differential scanning calorimetry (PDSC). The results show that the high pressure can decrease the DSC peak temperature, increase the decomposition heat; with the increase in the content of TEGDN, the decomposition heat decreases below 2MPa and rises at 4MPa. The high pressure can change the decomposition reaction mechanism and the kinetics of the DB gun propellant under 0.1MPa; the high TEGDN content does not change the mechanism functions, and the kinetic equation has a little difference between the sample and the control propellant; the high pressure makes the critical temperature (T(be)) of thermal explosion of the sample decrease, while the high TEGDN content make it present a increasing trend, and the DB gun propellant containing high content of TEGDN has a better thermal stability.

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

    Institute of Scientific and Technical Information of China (English)

    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%.

  20. Improved production of adipate with Escherichia coli by reversal of β-oxidation.

    Science.gov (United States)

    Kallscheuer, Nicolai; Gätgens, Jochem; Lübcke, Marvin; Pietruszka, Jörg; Bott, Michael; Polen, Tino

    2017-03-01

    The linear C6 dicarboxylic acid adipic acid is an important bulk chemical in the petrochemical industry as precursor of the polymer nylon-6,6-polyamide. In recent years, efforts were made towards the biotechnological production of adipate from renewable carbon sources using microbial cells. One strategy is to produce adipate via a reversed β-oxidation pathway. Hitherto, the adipate titers were very low due to limiting enzyme activities for this pathway. In most cases, the CoA intermediates are non-natural substrates for the tested enzymes and were therefore barely converted. We here tested heterologous enzymes in Escherichia coli to overcome these limitations and to improve the production of adipate via a reverse β-oxidation pathway. We tested in vitro selected enzymes for the efficient reduction of the enoyl-CoA and in the final reaction for the thioester cleavage. The genes encoding the enzymes which showed in vitro the highest activity were then used to construct an expression plasmid for a synthetic adipate pathway. Expression of paaJ, paaH, paaF, dcaA, and tesB in E. coli BL21(DE3) resulted in the production of up to 36 mg/L of adipate after 30 h of cultivation. Beside the activities of the pathway enzymes, the availability of metabolic precursors may limit the synthesis of adipate, providing another key target for further strain engineering towards high-yield production of adipate with E. coli.

  1. Contents

    Directory of Open Access Journals (Sweden)

    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  

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. ADIP ORNL contribution: 12th ADIP quarterly progress report for period October-December 1980. [Nb-1Zr

    Energy Technology Data Exchange (ETDEWEB)

    Puigh, R.; Duncan, D.; Ermi, A.M.; Gelles, D.; Zimmerchied, M.

    1980-01-01

    The following ADIP tasks are reported on: MFE-5 in-reactor fatigue crack growth in 316 SS in ORR, titanium alloy tensile properties after neutron irradiation in EBR-II, voids in neutron-irradiated Ti alloys, fabrication of ferritic alloys for RB-1 experiment in HFIR, microstructural examination of commercial ferritic alloys irradiated to very high fluence, microstructural examination of HT-9 archive material from the AD-2 test, and swelling of commercial alloys irradiated to a very high fluence. (DLC)

  4. Facile preparation of biodegradable chitosan derivative having poly(butylene glycol adipate) side chains.

    Science.gov (United States)

    Huang, Meifang; Fang, Yue'e

    2006-08-15

    Various modes are being explored for the construction of functional materials from nanoparticles. Despite these efforts, the assembly of nanoparticles remains challenging with respect to the requirement of multiple component organization on varying dimensions and length scales. The graft copolymers of chitosan with poly(butylene glycol adipate) (PBGA) were prepared due to the esterification reaction between PBGA and 6-O-succinate-N-phthaloyl-chitosan (PHCSSA) in the presence of toluene as a swelling agent. The graft copolymers are nanoparticles with the size of few hundred nanometers as observed from TEM. It is a potential method to combine chitosan with the hydrophobic synthetic polymers. The grafting reactions were conducted with various PBGA/PHCSSA feed ratios to obtain chitosan-g-PBGA copolymers with various PBGA contents. FT-IR, NMR, XRD, spectrofluorophotometer, and TEM were detected to characterize the copolymers. Copyright 2006 Wiley Periodicals, Inc.

  5. Ester Formation

    NARCIS (Netherlands)

    Lopez Garzon, C.S.; Straathof, A.J.J.

    2014-01-01

    The present invention is in the field of a process for producing an ester, such as a biobased ester, from an aqueous biomass comprising solution, batch wise or continuously, wherein use of raw material is limited and if possible re-used. The present invention is in the field of green technology.

  6. Ester Formation

    NARCIS (Netherlands)

    Lopez Garzon, C.S.; Straathof, A.J.J.

    2014-01-01

    The present invention is in the field of a process for producing an ester, such as a biobased ester, from an aqueous biomass comprising solution, batch wise or continuously, wherein use of raw material is limited and if possible re-used. The present invention is in the field of green technology.

  7. Amended final report of the safety assessment of dibutyl adipate as used in cosmetics.

    Science.gov (United States)

    Andersen, Alan

    2006-01-01

    Dibutyl Adipate, the diester of butyl alcohol and adipic acid, functions as a plasticizer, skin-conditioning agent, and solvent in cosmetic formulations. It is reportedly used at a concentration of 5% in nail polish and 8% in suntan gels, creams, and liquids. Dibutyl Adipate is soluble in organic solvents, but practically insoluble in water. Dibutyl Adipate does not absorb radiation in the ultraviolet (UV) region of the spectrum. Dibutyl Adipate is not toxic in acute oral or dermal animal toxicity tests. In a subchronic dermal toxicity study, 1.0 ml/kg day-1 caused a significant reduction in body weight gain in rabbits, but 0.5 ml/kg/day1 was without effect. In a study with dogs, no adverse effects were observed when an emulsion containing 6.25% Dibutyl Adipate was applied to the entire body twice a week for 3 months. Dibutyl Adipate was tested for dermal irritation using rabbits and mice and a none to minimal irritation was observed. Dibutyl Adipate at a concentration of 25% was not a sensitizer in a guinea pig maximization study. Undiluted Dibutyl Adipate was minimally irritating to the eyes of rabbits and 0.1% was nonirritating. A significant increase in fetal gross abnormalities was observed in rats given intraperitoneal injections of Dibutyl Adipate at 1.75 ml/kg on 3 separate days during gestation, but no effect was seen in animals given 1.05 ml/kg. Dibutyl Adipate was not genotoxic in either bacterial or mammalian test systems. Clinical patch tests confirmed the absence of skin irritation found in animal tests. Clinical phototoxicity tests were negative. Dibutyl Adipate at 0.1% was not an ocular irritant in two male volunteers. In a clinical test of comedogenicity, Dibutyl Adipate produced no effect. The Cosmetic Ingredient Review (CIR) Expert Panel recognized that use of Dibutyl Adipate in suntan cosmetic products will result in repeated, frequent exposure in a leave-on product. The available data demonstrate no skin sensitization or cumulative skin

  8. Evaporation of methyl- and dimethyl-substituted malonic, succinic, glutaric and adipic acid particles at ambient temperatures

    DEFF Research Database (Denmark)

    Mønster, Jacob Garbrecht; Rosenørn, Thomas; Svenningsson, Birgitta

    2004-01-01

    Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid......Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid...

  9. A flow-based procedure exploiting the lab-in-syringe approach for the determination of ester content in biodiesel and diesel/biodiesel blends.

    Science.gov (United States)

    Soares, Samara; Melchert, Wanessa R; Rocha, Fábio R P

    2017-11-01

    The ester content is an important parameter to be monitored in biodiesel for evaluation of the transesterification reaction yield and for assessing the purity of the final product. This is also a relevant quality parameter in diesel/biodiesel blends to avoid frauds, because legislation establishes a minimum amount of biodiesel to be added to diesel. The official method EN14103 requires the addition of an alternative internal standard (methyl nonadecanoate) for analysis of biodiesel from bovine tallow because the methyl heptadecanoate is found in high amounts in this product. In this work, it is proposed a fast, simple, practical, and environmental friendly flow-based spectrophotometric procedure, which exploits the formation of the violet complex between Fe(III) and the hydroxamate generated by the reactions of the alkyl esters with hydroxylamine. All involved steps are carried out inside the syringe pump of a sequential injection analyzer (lab-in-syringe approach). A single phase is attained by using ethanol as mediator solvent between the organic sample and aqueous soluble reagents. Linear responses for biodiesel samples and diesel/biodiesel blends were obtained from 4-99%(v/v) to 2.0-40%(v/v) methyl esters, described by the equations: A = 0.342 + 0.00305C (r = 0.997) and A = 0.174 + 0.00503C (r = 0.999), respectively. The analytical curve can be obtained by in-line dilution of a methyl linoleate stock solution. For biodiesel samples, the coefficient of variation (n = 10), limit of detection (99.7% confidence level), and sampling rate were estimated at 0.8%, 0.36%(v/v), and 15h(-1), respectively, whereas the corresponding values for the blend samples were 0.20%, 0.03%(v/v), and 12h(-1), respectively. The procedure consumes only 860μg of hydroxylamine, 366μg of Fe2(SO4)3·H2O, and 2.0mL ethanol and generates ca. 3.0mL of residue per determination. The results agreed with those obtained by official methods EN14103/2011 e EN14078, at the 95% confidence level

  10. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Science.gov (United States)

    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...

  11. Die respiratorische Katastrophe des adipösen Patienten

    Directory of Open Access Journals (Sweden)

    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.

  12. TNF-alfa e metabolismo do adipócito

    OpenAIRE

    Teixeira, Chantelle Simões Leite

    2015-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz A prevalência da obesidade tem vindo a aumentar ao longo dos anos influenciando a qualidade de vida da população, tornando-a mais suscetível ao desenvolvimento de outras patologias como as doenças cardiovasculares e a diabetes. A obesidade é resultante do aumento progressivo do tamanho do tecido adiposo em consequência de maior volume e número de adipócitos, levando a uma crescente síntetese d...

  13. TNF-alfa e metabolismo do adipócito

    OpenAIRE

    Teixeira, Chantelle Simões Leite

    2015-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz A prevalência da obesidade tem vindo a aumentar ao longo dos anos influenciando a qualidade de vida da população, tornando-a mais suscetível ao desenvolvimento de outras patologias como as doenças cardiovasculares e a diabetes. A obesidade é resultante do aumento progressivo do tamanho do tecido adiposo em consequência de maior volume e número de adipócitos, levando a uma crescente síntetese d...

  14. Alteration of Wax Ester Content and Composition in Euglena gracilis with Gene Silencing of 3-ketoacyl-CoA Thiolase Isozymes.

    Science.gov (United States)

    Nakazawa, Masami; Andoh, Hiroko; Koyama, Keiichiro; Watanabe, Yomi; Nakai, Takeo; Ueda, Mitsuhiro; Sakamoto, Tatsuji; Inui, Hiroshi; Nakano, Yoshihisa; Miyatake, Kazutaka

    2015-05-01

    Euglena gracilis produces wax ester under hypoxic and anaerobic culture conditions with a net synthesis of ATP. In wax ester fermentation, fatty acids are synthesized by reversing beta-oxidation in mitochondria. A major species of wax ester produced by E. gracilis is myristyl myristate (14:0-14:0Alc). Because of its shorter carbon chain length with saturated compounds, biodiesel produced from E. gracilis wax ester may have good cold flow properties with high oxidative stability. We reasoned that a slight metabolic modification would enable E. gracilis to produce a biofuel of ideal composition. In order to produce wax ester with shorter acyl chain length, we focused on isozymes of the enzyme 3-ketoacyl-CoA thiolase (KAT), a condensing enzyme of the mitochondrial fatty acid synthesis pathway in E. gracilis. We performed a gene silencing study of KAT isozymes in E. gracilis. Six KAT isozymes were identified in the E. gracilis EST database, and silencing any three of them (EgKAT1-3) altered the wax ester amount and composition. In particular, silencing EgKAT1 induced a significant compositional shift to shorter carbon chain lengths in wax ester. A model fuel mixture inferred from the composition of wax ester in EgKAT1-silenced cells showed a significant decrease in melting point compared to that of the control cells.

  15. Selected properties of acetylated adipate of retrograded starch.

    Science.gov (United States)

    Zięba, T; Gryszkin, A; Kapelko, M

    2014-01-01

    Native potato starch (NS) and retrograded starch (R - obtained via freezing and defrosting of a starch paste) were used to prepare starch acetates: NS-A and R-A, and then acetylated distarch adipates: NS-ADA and R-ADA. The chemically-modified preparations produced from retrograded starch (R-A; R-ADA) were characterized by a higher degree of esterification compared to the modified preparations produced under the same conditions from native potato starch (NS-A; NS-ADA). Starch resistance to amylolysis was observed to increase (to 30-40 g/100 g) as a result of starch retrogradation and acetylation. Starch cross-linking had a significant impact on the increased viscosity of the paste in the entire course of pasting characteristics and on the increased values of rheological coefficients determined from the equations describing flow curves. The produced preparation of acetylated retrograded starch cross-linked with adipic acid (R-ADA) may be deemed an RS3/4 preparation to be used as a food thickening agent.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Indian Academy of Sciences (India)

    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.

  18. Thermo stabilisation of poly (butylene adipate-co-terephthalate

    Directory of Open Access Journals (Sweden)

    Rodrigo Paulino Chaves

    Full Text Available Abstract Poly (butylene adipate-co-terephthalate - PBAT is a synthetic biodegradable polymer commonly used for plastic film production from neat polymer or nanocomposites. The PBAT is submitted to high temperatures and shear rate during its processing. In the present study, the thermo stabilisation of PBAT by the addition of two types of stabilisers was studied using a torque rheometer at 60 rpm and two levels of temperature. The stabilisers were used as master batches with a percentage of 10% by weight of additive in the PBAT. Molecular weight, torque values after 10 minutes of mixing, and absorbance at 400 nm were used to evaluate the process of stabilisation. The primary and secondary antioxidant used here had a positive effect on both processing temperatures, 180 and 200 °C. The best results indicate that the primary antioxidant could be used alone to protect PBAT against thermodegradation reactions.

  19. Effect of cross-linking degree on selected properties of retrograded starch adipate.

    Science.gov (United States)

    Kapelko, M; Zięba, T; Michalski, A; Gryszkin, A

    2015-01-15

    The aim of this study was to determine the effects of the concentration of paste used to produce retrograded starch, and esterification degree, on selected properties of the resultant distarch adipate. Starch paste was prepared from native potato starch (1, 4, 10, 18 or 30 g/100g), frozen, defrosted and dried. Thus produced preparations of retrograded starch were cross-linked with various doses of a cross-linking agent (0.125, 0.25, 0.5, 1.0 or 2.0 ml per 100g of starch). Properties of the produced adipates depended on both the concentration of paste used to produce retrograded starch and the degree of substitution with adipic acid residues. Solubility in water and swelling power of the cross-linked preparations of retrograded starch, as well as pasting temperature and viscosity of produced pastes, all decreased along with the increasing degree of substitution with adipic acid residues.

  20. Poly(Butylene Succinate) and Poly[(Butylene Succinate)-co-Adipate] Nanocomposites

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2012-01-01

    Full Text Available , and properties of nanoclay-containing composites of biodegradable poly(butylene succinate) (PBS) and poly[(butylene succinate)-co-adipate] (PBSA). Various nanocomposite structures arising from the incorporation of layered silicate particles, both pristine...

  1. A Study on Processing Materials of Instant Tea with High Ester-catechin and EGCG Contents%高酯型儿茶素和EGCG含量的速溶茶加工原料研究

    Institute of Scientific and Technical Information of China (English)

    林金科; 赵文净; 吴亮宇; 杨志坚; 涂良剑; 孙平; 林艺端; 张明泽; 商虎

    2013-01-01

    为解决目前速溶茶中酯型儿茶素和EGCG(表没食子儿茶素没食子酸酯)含量较低的问题,分别以不同季节的茶叶和不同品种的乌龙茶为加工原料生产速溶茶产品,采用高效液相色谱法检测分析速溶茶产品中的酯型儿茶素和EGCG含量,采用Duncan法进行数据分析.研究结果表明,不同采摘季节的茶叶为加工原料或不同乌龙茶品种的茶叶为加工原料,其生产出的速溶茶产品中酯型儿荼素和EGCG含量差异分别达显著水平.与春茶为加工原料相比,选用乌龙茶秋茶或绿茶夏茶为加工原料生产速溶茶,显著提高了产品中的酯型儿茶素和EGCG含量;与‘铁观音’品种相比,选用‘单枞’或‘毛蟹’品种的乌龙茶为加工原料生产速溶茶,显著提高了速溶乌龙茶产品中的酯型儿茶素和EGCG含量.%The aim of this research was to solve the problem of low contents of ester-catechins and EGCG (epigallocatechin gallate) in instant tea. Using different processing raw materials of oolong tea or green tea plucked in different seasons and of oolong tea plucked from different varieties, different kinds of instant tea were produced. The contents of ester-catechins and EGCG were detected by HPLC. It was confirmed that the contents of ester-catechins and EGCG in instant oolong tea processed from fall oolong tea were higher than that from spring. The contents of ester-catechins and EGCG in instant green tea processed from summer green tea were higher than that from spring. There were significant differences in the contents of ester-catechins and EGCG in instant oolong tea made from different cultivars and the order followed 'Dancong' >' Maoxie' >' Tie Guanyin'.

  2. Topological aspects of lanthanide-adipate-aqua compounds: Close packed and open framework structures

    Science.gov (United States)

    Chowdhuri, Durga Sankar; Kumar Jana, Swapan; Hazari, Debdoot; Zangrando, Ennio; Dalai, Sudipta

    2013-07-01

    A search in the Cambridge Structural Database (CSD) for lanthanide complexes with adipate [OOC(CH2)4COO]2- and aqua ligands retrieved a fair number of compounds. To this dataset a new lanthanum metal-organic framework, {[La2(adip)3(H2O)2] (1) (adipH2=adipic acid), synthesised and structurally characterized in these labs, was included. The crystal structures of these coordination polymers, of general formulation [Ln2(adip)3(H2O)x], exhibit a variety of topologies and dimensionality, which were clustered in different classes and described in detail. It was explored that the majority of these evidences the presence of metal chains or dinuclear Ln2 entities (separated in both cases by 4.0-4.8 Å), where lanthanide ions are differently connected by carboxylate groups with chelating or oxygen-bridging mode. The different amount of coordinated water molecules appear to affect the solid state networks. Moreover the crystal packing of these compounds shows peculiar aspects and examples were reported in the literature where the long alkyl chain of adipate connectors give rise to interpenetrated structures, or to porous material where lattice water or neutral larger molecules are clathrated.

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

    DEFF Research Database (Denmark)

    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...... and the formed acetyl-CoA was metabolized in the glyoxylate shunt. This hypothesis was further substantiated by an enzyme assay, which showed activity of the key enzyme in the glyoxylate shunt. Flux estimations in two chemostat cultures, one with and one without adipate in the feed, revealed that degradation...... of adipate in the production of 7-ADCA. Using C-13-labeled glucose and measurement of metabolite labeling patterns, it was shown that adipate was degraded by beta-oxidation to succinyl-CoA and acetyl-CoA. The labeling analysis indicated that degradation of adipate was taking place in the microbodies...

  4. Influence on the physicochemical properties of fish collagen gels using self-assembly and simultaneous cross-linking with the N-hydroxysuccinimide adipic acid derivative.

    Science.gov (United States)

    Shen, Lirui; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-06-01

    Collagen gels from Southern catfish (Silurus meridionalis Chen) skins were prepared via the self-assembly of collagen molecules and simultaneous cross-linking with the N-hydroxysuccinimide adipic acid derivative (NHS-AA). The doses of NHS-AA were converted to [NHS-AA]/[NH2] ratios (0.025-1.6, calculated by the [active ester group] of NHS-AA and [ε-NH2] of lysine and hydroxylysine residues of collagen). When the ratio collagen gels were formed by collagen molecule self-assembly, resulting in the opalescent appearance of collagen gels and the characteristic D-periodicity of partial collagen fibrils, the collagen gel ([NHS-AA]/[NH2] = 0.05) displayed a small increase in denaturation temperature (Td, 42.8 °C), remaining weight (12.59%), specific water content (SWC 233.7) and elastic modulus (G' 128.4 Pa) compared with uncross-linked collagen gel (39.1 °C, 9.12%, 222.4 and 85.4 Pa, respectively). As the ratio > 0.05, disappearance of D-periodicity and a gradual change in appearance from opalescent to transparent suggested that the inhibition of NHS-AA in the self-assembly of collagen molecules was more obvious. As a result, the collagen gel ([NHS-AA]/[NH2] = 0.2) had the lowest Td (35.8 °C), remaining weight (7.96%), SWC (130.9) and G' (31.9 Pa). When the ratio was 1.6, the collagen molecule self-assembly was markedly suppressed and the formation of collagen gel was predominantly via the covalent cross-linking bonds which led to the transparent appearance, and the maximum values of Td (47.0 °C), remaining weight (45.92%) and G' (420.7 Pa) of collagen gel. These results indicated that collagen gels with different properties can be prepared using different NHS-AA doses.

  5. Catalytic Synthesis of Ethyl Ester From Some Common Oils ...

    African Journals Online (AJOL)

    ... seed oil FAEE that shows high acid value and total ash content the esters could be used directly or as blend in diesel engines to give good performance. Key words: Ethyl ester, synthesis, catalytic activity, common oils, biodiesel potential.

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

    Science.gov (United States)

    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. A limited LCA of bio-adipic acid: Manufacturing the nylon-6,6 precursor adipic acid using the benzoic acid degradation pathway from different feedstocks

    NARCIS (Netherlands)

    Duuren, van J.B.J.H.; Brehmer, B.; Mars, A.E.; Eggink, G.; Martins Dos Santos, V.A.P.; Sanders, J.P.M.

    2011-01-01

    A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, tol

  8. HPLC法测定千金子不同极性部位中二萜酯类化合物含量%Comparison of Content of Diterpene Esters from Different Polar Fractions in Euphorbiae Semen by HPLC Method

    Institute of Scientific and Technical Information of China (English)

    张超; 朱娟娟; 王英姿; 孙秀梅

    2014-01-01

    目的:考察千金子素L8、千金子素L1、千金子素L2、千金子素L3四种化合物在千金子不同极性部位的分布情况。方法:用HPLC测定,色谱柱为Inertsil ODS-3(250 mm×4.6 mm,5μm),流动相为甲醇-水(75∶25),流速1.0 mL·min-1,柱温25℃;检测波长275 nm。结果:4个二萜酯类化合物在石油醚部位中含量最高,在乙酸乙酯和正丁醇部位中较少,在剩余水部位基本检测不到二萜酯类化合物。结论:该方法准确简便,重现性好,可用于比较千金子不同极性部位二萜酯类化合物的分布情况。%Objective:To study the distribution of euphorbia factor L8,euphorbia factor L1,euphorbia factor L2 and euphorbia factor L3 in the different polar fractions of Euphorbiae semen. Methods:Using HPLC method determine the content of 4 ingredients. The column is performed on Inertsil ODS-3(250 mm×4.6 mm,5μm), with mobile phase for methanol and water(75∶25),velocity 1.0 mL·min-1,column temperature 25℃,275 nm wavelength detection. Results:The content of diterpene esters was the highest in the petroleum ether fraction of Euphorbiae semen. The content of diterpene esters was lower in the fractions of acetic ether and n-bu-tanol. In the remaining part of water,the diterpene esters were undetected. Conclusion:The method is sim-ple,accurate and well reproducibile,so it can be used to compare the content of diterpene esters from dif-ferent polar fractions in Euphorbiae semen.

  9. 啤酒发酵过程对重要醇酯影响的研究%The Effects of Beer Fermentation on the Content of Higher Alcohols and Esters

    Institute of Scientific and Technical Information of China (English)

    钟成; 杨攀飞; 刘伶普; 郝俊光; 贾士儒

    2015-01-01

    风味物质的含量决定啤酒的品质,其特征会直接决定啤酒口感和其市场竞争力。研究了麦汁浓度、主酵温度和接种量对啤酒中风味物质的影响。在不同的发酵条件下,以全麦芽为原料,经下面发酵生产啤酒。采用顶空气相色谱法检测啤酒中高级醇和酯类的浓度。研究发现麦汁浓度对高级醇和酯的影响最大,且提高麦汁浓度能够同时增大啤酒中高级醇和酯的含量,当麦汁浓度从11°P提高到15°P,乙酸乙酯的含量提高了34%。在相同接种量和麦汁浓度下,主酵温度越高,异戊醇含量越高,异丁醇的含量却有所降低。在较高的发酵温度下乙酸乙酯、辛酸乙酯和乙酸异戊酯的含量升高,但是己酸乙酯的含量变化无规律。研究结果显示接种量对醇和酯的影响都不显著。%The content of flavoring substances determines the quality of beer and the flavoring characteristics will directly determine the taste and market competitiveness of beer product. In this study, the effects of wort concentration, chief fermenting temperature and barm inoculating quantity on flavoring substances in beer were investigated. In the experiments, beer was produced with whole malt as raw materials by bottom fermentation under different fermenting conditions. The content of higher alcohols and esters were detected by HS-GC. The experimental re-sults suggested that wort concentration among the three factors had the greatest effects on higher alcohols & esters content. The enhance of wort concentration could increase both higher alcohols content and esters content at the same time. As wort concentration got enhanced from 11° P to 15° P, the content of ethyl caproate increased by 34%. Under the conditions of the same barm inoculating quantity and the same wort concentration, higher chief fermenting temperature might induce higher content of isoamylol but lower content of isobutanol. The content of

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

    Science.gov (United States)

    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. Síntese de β-cetoésteres cíclicos: novo procedimento para ciclizações de Dieckmann empregando ALCL3 e trietilamina Synthesis of β-keto esters: new easy procedure for dieckmann cyclization employing aluminum chloride and triethylamine

    Directory of Open Access Journals (Sweden)

    Emerson P. Peçanha

    1997-08-01

    Full Text Available In this communication we describe a new methodology to Dieckmann cyclization of diethyl adipate (1 and diethyl pimelate (3 applying "push-pull" strategy using anhydrous aluminium trichloride and triethylamine in dichloromethane at room temperature. This method is very efficient, simple, safe and reproducible, giving the corresponding cyclic β-keto ester derivatives in 84% and 71% yield, respectively.

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

    DEFF Research Database (Denmark)

    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...

  13. Development of poly(glycerol adipate) nanoparticles loaded with non-steroidal anti-inflammatory drugs.

    NARCIS (Netherlands)

    Wahab, A.; Favretto, M.E.; Onyeagor, N.D.; Khan, G.M.; Douroumis, D.; Casely-Hayford, M.A.; Kallinteri, P.

    2012-01-01

    The aim of this study was to assess acylated and non-acylated poly(glycerol adipate) polymers (PGA) as suitable nanoparticulate systems for encapsulation and release of ibuprofen, ibuprofen sodium salt (IBU-Na) and ketoprofen as model drugs. Drug encapsulated nanoparticles were prepared using the in

  14. Viscoelastic properties of poly(butylene succinate)-co-adipate) nanocomposites

    CSIR Research Space (South Africa)

    Al-Thabaiti, SA

    2015-03-01

    Full Text Available This article reports the viscoelastic properties of poly[(butylene succinate)-co-adipate] (PBSA) nanocomposites. The nanocomposites of PBSA with various loadings of organically modified clay were prepared by melt-mixing in a batch-mixer. The solid...

  15. Multifunctional nanobiocomposite of Poly[(butylene succinate)-co-adipate] and clay

    CSIR Research Space (South Africa)

    Al-Thabaiti, SA

    2015-03-01

    Full Text Available and Nanotechnology Vol. 15, 2446-2450 Multifunctional Nanobiocomposite of Poly[(butylene succinate)- co-adipate] and Clay Shaeel A. Al-Thabaiti1, Suprakas Sinha Ray1_ 2_ ∗, Sulaiman Nassir Basahel1, and Mohamed Mokhtar1 1Department of Chemistry, King...

  16. Production of Adipic Acid from Mixtures of Cyclohexanol-Cyclohexanone using Polyoxometalate Catalysts

    Directory of Open Access Journals (Sweden)

    Aldes Lesbani

    2015-06-01

    Full Text Available Adipic acid production through catalytic conversion of cyclohexanol-cyclohexanone using polyoxometalate H5[a-BW12O40] and H4[a-SiW12O40] as catalysts was carried out systematically. Polyoxometalates H5[a-BW12O40] and H4[a-SiW12O40] were synthesized using an inorganic synthesis method and were characterized using Fourier transform infrared spectroscopy (FTIR. Adipic acid was formed from conversion of cyclohexanol-cyclohexanone and was characterized by using melting point measurement, identification of functional group using FTIR spectrophotometer, analysis of gas chromatography-mass spectrometry (GC-MS, and 1H and 13C NMR (nuclear magnetic resonance spectrophotometer. This research investigated the influence of reaction time and temperature on the conversion. The results showed that adipic acid was formed successfully with a yield of 68% by using H5[a-BW12O40] as the catalyst with a melting point of 150-152 °C after optimization. In contrast, using H4[a-SiW12O40] as the catalyst, the formation was only 3.7%. Investigation of time and temperature showed 9 h as the optimum reaction time and 90 °C as the optimum temperature for conversion of up to 68%. Identification using FTIR, 1H, and 13C NMR showed that the adipic acid from conversion of cyclohexanol-cyclohexanone was in agreement with the standard adipic acid data in the literatures. GC-MS analysis indicated that several by-products were formed in conversion of cyclohexanol-cyclohexanone using H5[a-BW12O40] and H4[a-SiW12O40] as the catalysts.

  17. Application conditions for ester cured alkaline phenolic resin sand

    Institute of Scientific and Technical Information of China (English)

    Ren-he Huang; Bao-ping Zhang; Yao-ji Tang

    2016-01-01

    Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A); 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B); glycerol diacetate; dibasic ester (DBE) (i.e. low-speed ester C), were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand) and the amount of added organic ester and curing temperature were investigated. The results indicated the folowing: (1) The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2) High-speed ester A (propylene carbonate) has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3) High-speed ester A, medium-speed ester B (glycerol triacetate) and low-speed ester C (dibasic ester, i.e., DBE) should be used below 15 ºC, 35 ºC and 50 ºC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4) There should be a suitable solid content (generaly 45wt.%-65wt.% of resin), alkali content (generaly 10wt.%-15wt.% of resin) and viscosity of alkaline phenolic resin (generaly 50-300 mPa·s) in the preparation of alkaline phenolic resin. Finaly, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  18. Content

    DEFF Research Database (Denmark)

    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......; Race, 2001; Ramsden, 2003). This trend appears closely related to the ‘from-teaching-to-learning’ movement, which has had a strong influence on pedagogy since the early nineties (Keiding, 2007; Terhart, 2003). Another interpretation of the current interest in methodology can be derived from...... for selection of content (Klafki, 1985, 2000; Myhre, 1961; Nielsen, 2006). These attempts all share one feature, which is that criteria for selection of content appear very general and often, more or less explicitly, deal with teaching at the first Bologna-cycle; i.e. schooling at the primary and lower...

  19. Toughening of biodegradable polylactide/poly(butylene succinate-co-adipate) blends via in situ reactive compatibilization.

    Science.gov (United States)

    Ojijo, Vincent; Ray, Suprakas Sinha; Sadiku, Rotimi

    2013-05-22

    Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization. Moreover, optimization of parameters such as the mixing sequence and time, TPP content, and PBSA concentration revealed that blends containing 30 and 10 wt % PBSA and 2 wt % TPP, which were processed for 30 min, were optimal in terms of thermomechanical properties. The impact strength increased from 6 kJ/m(2) for PLA to 11 and 16 kJ/m(2) for blends containing 30 and 10 wt % PBSA, respectively, whereas the elongation-at-break increased from 6% for PLA to 20 and 37% for blends containing 30 and 10 wt % PBSA, respectively. Upon compatibilization, the failure mode shifted from the brittle fracture of PLA to ductile deformation, effected by the debonding between the two phases. With improved phase adhesion, compatibilized blends not only were toughened but also did not significantly lose tensile strength and thermal stability.

  20. A limited LCA of bio-adipic acid: manufacturing the nylon-6,6 precursor adipic acid using the benzoic acid degradation pathway from different feedstocks.

    Science.gov (United States)

    van Duuren, J B J H; Brehmer, B; Mars, A E; Eggink, G; Dos Santos, V A P Martins; Sanders, J P M

    2011-06-01

    A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, toluene, or phenol from lignin to cis, cis-muconic acid, which is subsequently converted to adipic acid through hydrogenation. Apart from the impact of usage of petrochemical and biomass-based feedstocks, the environmental impact of the final concentration of cis, cis-muconic acid in the fermentation broth was studied using 1.85% and 4.26% cis, cis-muconic acid. The LCA focused on the cumulative energy demand (CED), cumulative exergy demand (CExD), and the CO(2) equivalent (CO(2) eq) emission, with CO(2) and N(2) O measured separately. The highest calculated reduction potential of CED and CExD were achieved using phenol, which reduced the CED by 29% and 57% with 1.85% and 4.26% cis, cis-muconic acid, respectively. A decrease in the CO(2) eq emission was especially achieved when the N(2) O emission in the combined biological and chemical process was restricted. At 4.26% cis, cis-muconic acid, the different carbon backbone feedstocks contributed to an optimized reduction of CO(2) eq emissions ranging from 14.0 to 17.4 ton CO(2) eq/ton adipic acid. The bulk of the bioprocessing energy intensity is attributed to the hydrogenation reactor, which has a high environmental impact and a direct relationship with the product concentration in the broth.

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

    Indian Academy of Sciences (India)

    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.

  2. 利用醋酸发酵液提高清香型白酒中酸酯含量的研究%Improving the content of acids and esters of fen-flavor liquor using ending liquor

    Institute of Scientific and Technical Information of China (English)

    王文阳; 肖冬光; 杜丽平; 张艳英; 陈原

    2012-01-01

    Using ending liquor of fen-flavor liquor's by products as the main components of the medium, the acetic acid liquid by acetic fermentation was obtained, and then utilized in the production of fen-liquor. The effects of adding amount of acetic acid liquid on fermentation and contents of acids and esters of fen-flavor liquor were studied. The results were as follows: Adding acetic acid liquid increased the acidity of the fermented grains, resulted to the alcohol content decreased slightly in the fermented grains, but adding acetic acid liquid could improve the main acids and esters significantly. According to the physiochemical parameters, when adding acetic acid liquid and made the acidity of the fermented grains reached 3.0mg/g, the acids and esters improved significantly, the acetic acid and ethyl acetate increased by 138.35% and 85.43%, respectively, and the total esters of two fermentations increased by 25.93%.%以清香型白酒生产的副产物大曲酒尾为培养基主要成分,经醋酸发酵制取醋酸发酵液,将其应用于清香型白酒生产中,通过考察醋酸发酵液的添加量,研究了其对酒醅发酵和清香型白酒酸酯含量的影响.试验结果表明,采用“清蒸二次清”工艺,在大(米查)酒醅发酵时添加醋酸发酵液,发酵结束后大(米查)酒醅酒精度略微下降,但添加醋酸发酵液可明显提高大渣酒中的主体酸酯含量;二(米查)酒醅发酵按照传统工艺进行,发酵结束后二(米查)酒醅酒精度呈增加趋势,二(米查)酒中的酸酯含量与对照无明显变化.理化指标结果表明,当醋酸发酵液添加量使大(米查)酒醅含量为3.0mg醋酸/g醅时,酒中主体酸酯含量提高较为显著,大(米查)酒中乙酸和乙酸乙酯分别提高了138.35%和85.43%,2次发酵总酯提高了25.93%.

  3. 塑料食品包装中邻苯二甲酸酯类塑化剂含量调查%Investigation on the content of phthalate acid esters plasticizers in plastic food packaging

    Institute of Scientific and Technical Information of China (English)

    陈明; 商贵芹; 王红松

    2013-01-01

    Objective To understand the situation of 18 kinds of phthalic acid esters in plastic food packaging.Methods The contents of phthalic acid esters in 280 plastic food packaging of different materials were analyzed by gas chromatography-mass spectrometry (GC-MS) following standard GB/T 21928-2008.The samples were extracted ultrasonically with n-hexane,then separated by HP-5MS capillary column and detected by single quadrupole mass spectrometry.Retention time and characteristic ions were used as qualitative evidence,and external standard was used for quantification.Results The content of 18 kinds of phthalate in 95% of the 62 batches of PVC materials were qualified,all 82 batches of composite materials and 136 batches of other materials were qualified.Diethylhexylphthalate residues were detected,and seriously exceeded the standard limit in 3 polyvinyl chloride materials.Conclusion The phthalic acid esters exposure from plastic food packaging was low,while polyvinyl chloride materials put a potential health risk to human.Regulation and monitoring on phthalic acid esters in plastic food packaging should be strengthened.%目的 了解塑料食品包装中18种邻苯二甲酸酯的含量现状.方法 选取280批不同材质的塑料食品包装,依据GB/T 21928-2008《食品塑料包装材料中邻苯二甲酸酯的测定》采用气相色谱-质谱法进行检测.以正已烷为提取溶剂,超声波提取,采用HP-5MS石英毛细管柱(30 m×0.25 mm,0.25 μm)色谱柱程序升温分离,以保留时间和特征离子为定性依据,外标法定量.结果 62批聚氯乙烯材质的食品包装中18种邻苯二甲酸酯含量95%小于法规限量,82批复合材质和136批其它材质的食品包装中18种邻苯二甲酸酯含量100%小于法规限量,检出最多的是邻苯二甲酸二(2-乙基)己酯,3批聚氯乙烯材质的食品包装中邻苯二甲酸二(2-乙基)己酯严重超标.结论 塑料食品包装中邻苯二甲酸酯暴露水平较低,聚氯乙烯

  4. CONTENTS

    Institute of Scientific and Technical Information of China (English)

    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".

  5. 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.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Preparation of Nanocellulose Reinforced Chitosan Films, Cross-Linked by Adipic Acid.

    Science.gov (United States)

    Falamarzpour, Pouria; Behzad, Tayebeh; Zamani, Akram

    2017-02-13

    Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80-100 °C as verified by Fourier transform infrared (FT-IR). The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min) were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured), chemically cross-linked (cured), and uncross-linked (prepared by acetic acid) films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs) on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials.

  7. Preparation of Nanocellulose Reinforced Chitosan Films, Cross-Linked by Adipic Acid

    Directory of Open Access Journals (Sweden)

    Pouria Falamarzpour

    2017-02-01

    Full Text Available Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80–100 °C as verified by Fourier transform infrared (FT-IR. The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured, chemically cross-linked (cured, and uncross-linked (prepared by acetic acid films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials.

  8. Metabolism of phytanic acid and 3-methyl-adipic acid excretion in patients with adult Refsum disease.

    Science.gov (United States)

    Wierzbicki, Anthony S; Mayne, Phillip D; Lloyd, Matthew D; Burston, David; Mei, Guam; Sidey, Margaret C; Feher, Michael D; Gibberd, F Brian

    2003-08-01

    Adult Refsum disease (ARD) is associated with defective alpha-oxidation of phytanic acid (PA). omega-Oxidation of PA to 3-methyl-adipic acid (3-MAA) occurs although its clinical significance is unclear. In a 40 day study of a new ARD patient, where the plasma half-life of PA was 22.4 days, omega-oxidation accounted for 30% initially and later all PA excretion. Plasma and adipose tissue PA and 3-MAA excretion were measured in a cross-sectional study of 11 patients. The capacity of the omega-oxidation pathway was 6.9 (2.8-19.4) mg [20.4 (8.3-57.4) micromol] PA/day. 3-MAA excretion correlated with plasma PA levels (r = 0.61; P = 0.03) but not adipose tissue PA content. omega-Oxidation during a 56 h fast was studied in five patients. 3-MAA excretion increased by 208 +/- 58% in parallel with the 158 (125-603)% rise in plasma PA. Plasma PA doubled every 29 h, while 3-MAA excretion followed second-order kinetics. Acute sequelae of ARD were noted in three patients (60%) after fasting. The omega-oxidation pathway can metabolise PA ingested by patients with ARD, but this activity is dependent on plasma PA concentration. omega-Oxidation forms a functional reserve capacity that enables patients with ARD undergoing acute stress to cope with limited increases in plasma PA levels.

  9. Variability of some diterpene esters in coffee beverages as influenced by brewing procedures.

    Science.gov (United States)

    Moeenfard, Marzieh; Erny, Guillaume L; Alves, Arminda

    2016-11-01

    Several coffee brews, including classical and commercial beverages, were analyzed for their diterpene esters content (cafestol and kahweol linoleate, oleate, palmitate and stearate) by high performance liquid chromatography with diode array detector (HPLC-DAD) combined with spectral deconvolution. Due to the coelution of cafestol and kahweol esters at 225 nm, HPLC-DAD did not give accurate quantification of cafestol esters. Accordingly, spectral deconvolution was used to deconvolve the co-migrating profiles. Total cafestol and kahweol esters content of classical coffee brews ranged from 5-232 to 2-1016 mg/L, respectively. Commercial blends contained 1-54 mg/L of total cafestol esters and 2-403 mg/L of total kahweol esters. Boiled coffee had the highest diterpene esters content, while filtered and instant brews showed the lowest concentrations. However, individual diterpene esters content was not affected by brewing procedure as in terms of kahweol esters, kahweol palmitate was the main compound in all samples, followed by kahweol linoleate, oleate and stearate. Higher amounts of cafestol palmitate and stearate were also observed compared to cafestol linoleate and cafestol oleate. The ratio of diterpene esters esterified with unsaturated fatty acids to total diterpene esters was considered as measure of their unsaturation in analyzed samples which varied from 47 to 52%. Providing new information regarding the diterpene esters content and their distribution in coffee brews will allow a better use of coffee as a functional beverage.

  10. Ester Tuiksoo / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Juhan Partsi valitsuse (05.04.2004-13.04.2005) ja Andrus Ansipi valitsuse (13.04.2005-) põllumajandusminister Ester Tuiksoo oma lapsepõlvest ja elukutsevalikust, poliitilise karjääri algusest ja erakonna valikust, ministritöö kogemustest, naistest poliitikas

  11. Ester Tuiksoo / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Juhan Partsi valitsuse (05.04.2004-13.04.2005) ja Andrus Ansipi valitsuse (13.04.2005-) põllumajandusminister Ester Tuiksoo oma lapsepõlvest ja elukutsevalikust, poliitilise karjääri algusest ja erakonna valikust, ministritöö kogemustest, naistest poliitikas

  12. Effect of nanoclay loading on the thermal and mechanical properties of biodegradable polylactide/poly[(butylene succinate)-co-adipate] blend composites.

    Science.gov (United States)

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-05-01

    Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0 to 9%. Small angle X-ray scattering patterns showed slightly better dispersion in PBSA than PLA, and there was a tendency of the silicate layers to delaminate in PBSA at low clay content. Thermal analysis revealed that crystallinity was dependent on the clay content as well its localization within the composite. On the other hand, thermal stability marginally improved for composites with 2 wt %. Tensile properties showed dependence on clay content and localization. Composite with 2 wt % clay content showed slight improvement in elongation at break. Overall, the optimum property was found for a composite with 2 wt % of the organoclay. This paper therefore has demonstrated the significance of the clay content and localization on the properties of the PLA/PBSA blends.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    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 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......-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...

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, A; Poust, S; De Rond, T; Fortman, JL; Katz, L; Petzold, CJ; Keasling, JD

    2015-10-26

    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.

  17. Rapid NIR determination of alkyl esters in virgin olive oil

    Directory of Open Access Journals (Sweden)

    J. A. Cayuela

    2017-06-01

    Full Text Available The regulation of The European Union for olive oil and olive pomace established the limit of 35 mg·kg-1 for fatty acids ethyl ester contents in extra virgin olive oils, from grinding seasons after 2016. In this work, predictive models have been established for measuring fatty acid ethyl and methyl esters and to measure the total fatty acid alkyl esters based on near infrared spectroscopy (NIRS, and used successfully for this purpose. The correlation coefficients from the external validation exercises carried out with these predictive models ranged from 0.84 to 0.91. Different classification tests using the same models for the thresholds 35 mg·kg-1 for fatty acid ethyl esters and 75 mg·kg-1 for fatty acid alkyl esters provided success percentages from 75.0% to 95.2%.

  18. Apomorphine and its esters

    DEFF Research Database (Denmark)

    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...... cells. Molecular dynamics (MD) simulations were performed to understand the stability of the esters on a molecular level. The affinity of the compounds towards plasma derived chylomicrons was assessed. The A-B transport of intact DLA was about 150 times lower than the transport of apomorphine...

  19. Cellulose nanocrystal and poly[di(ethylene glycol) adipate] blend for tunable lens

    Science.gov (United States)

    Ko, Hyun-U.; Kim, Hyun Chan; Li, Yaguang; Kim, Sang Youn; Kim, Jaehwan

    2016-04-01

    In these days, consumer electronics and medical device for optical diagnosis are minimalized and mobilized. The focusing part is one of crucial parts of optical diagnosis systems to reduce the size and weight. Thus, demand for tunable lens that change the focus itself is increased. To meet the demand, many tunable lens has been studied by utilizing smart materials that responded under mechanical, magnetic, optical, thermal, chemical, electrical or electrochemical stimuli. This paper reports a cellulose nanocrystal (CNC) and poly[di(ethylene glycol) adipate] (PDEGA) blend that is able to respond under electromechanical stimulus. The preparation of CNC/PDEGA and its characterization are illustrated and its actuation behavior is tested . Because the material has high dielectric constant and high reflection index, it is good candidate material for tunable lens.

  20. Aqueous solubility and Daphnia magna chronic toxicity of di(2-ethylhexyl) adipate.

    Science.gov (United States)

    Robillard, K A; Dufresne, D L; Gorsuch, J W; Stubblefield, W A; Staples, C A; Parkerton, T F

    2008-06-01

    A water solubility of 5.5 (+/-0.22) microg/L for di(2-ethylhexyl) adipate (DEHA) was measured using the slow-stir method. This value is consistent with computer estimations and over two orders of magnitude lower than that previously determined using the shake-flask method. We performed a 21-day chronic Daphnia magna limit test at an average exposure of 4.4 microg/L in laboratory diluent water to avoid insoluble test material and avoid physical entrapment. One hundred percent of the DEHA-treated organisms survived compared to 90% survival in both the controls and solvent controls. Mean neonate reproduction was 152, 137, and 148 and mean dry weight per surviving female was 0.804, 0.779, and 0.742 mg in the DEHA treatment, control, and solvent control, respectively. No adverse effects were observed.

  1. Drug incorporation and release of water soluble drugs from novel functionalized poly(glycerol adipate) nanoparticles.

    Science.gov (United States)

    Puri, Sanyogita; Kallinteri, Paraskevi; Higgins, Sean; Hutcheon, Gillian A; Garnett, Martin C

    2008-01-04

    We have previously demonstrated the ability of poly(glycerol adipate) backbone (PGA) and PGA polymer backbone substituted with varying amounts of pendant C(18) chain length acyl groups to yield Dexamethasone phosphate DXMP loaded nanoparticles. The aim of this study was to obtain a deeper understanding of the underlying principles responsible for good drug incorporation and controlled release of drugs from poly (glycerol adipate) (PGA) nanoparticles. We compared the incorporation of the water soluble drugs DXMP and Cytosine arabinoside (CYT-ARA) in both unmodified and substituted PGA polymers. We investigated the effect of change in acyl group chain length and the degree of substitution on the physicochemical properties, drug loading and release of DXMP and CYT-ARA. Nanoparticles were prepared by the interfacial deposition technique and the simultaneous emulsification method. Amongst the nanoparticles prepared using acylated polymers with varying chain lengths (C(2) to C(10)) for DXMP incorporation, polymers with acyl group chain lengths containing 8 carbon atoms (C(8)) showed maximum drug incorporation. Amongst the C(8) series, polymers with 100% acylation provided both good drug incorporation and a controlled release for DXMP while for CYT-ARA it was the unsubstituted polymer backbone that had maximum drug loading and slower release. A number of inter-related factors are responsible for producing particles with particular size, zeta potential, drug loading and release characteristics. Drug loading and release from nanoparticles are primarily influenced by the nature of interactions between the drug and polymers which in turn depend upon the type of drug used and the physical chemistry of the polymer.

  2. Synthesis, Characterization, and Biodegradation Studies of Poly(1,4-cyclohexanedimethylene-adipate-carbonates

    Directory of Open Access Journals (Sweden)

    Ajay S. Chandure

    2014-01-01

    Full Text Available Aliphatic/alicyclic poly(1,4-cyclohexanedimethylene-adipate-carbonates (PCACs were synthesized by a transesterification from 1,4-cyclohexamethylendimethanol (1,4-CHDM, adipic acid (AA, diethyl carbonate (DEC, and titanium butoxide Ti(OBu4 as a transesterification catalyst. The synthesized PCACs were characterized by the Fourier transform infrared (FTIR, X-ray diffraction analysis (XRD, solubility, solution viscosity, gel permeation chromatography (GPC, differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, and scanning electron microscope (SEM for their structural, physical, thermal, and morphological investigation. The structure of synthesized PCACs was confirmed by FTIR. All TGA curves of PCACs shows 10% weight loss above 270°C, and they reveal good thermal stability. Biodegradability of PCACs was investigated by hydrolytic degradation at (pH 7.2 and 11.5, enzymatic degradation using Rhizopus delemar lips at 37°C in phosphate buffer solution (PBS, and soil burial degradation at 30°C. The hydrolytic degradation shows the greater rate of weight loss in PBS at pH-11.5 than pH-7.2. The hydrolytic and soil burial degradation shows faster rate of weight loss as compared to enzymatic degradation. Biodegradation rate of PCACs follows the order: PCAC-20 > PCAC-40 > PCAC-60. SEM images show that degradation occurred all over the film surface, creating holes and cracks. These biodegradable PCACs may be able to replace conventional polymer in the fabrication of packaging film in near future.

  3. Miscibility, Morphology and Crystallization Behavior of Poly(Butylene Succinate-co-Butylene Adipate/Poly(Vinyl Phenol/Poly(l-Lactic Acid Blends

    Directory of Open Access Journals (Sweden)

    Pengfei Si

    2016-12-01

    Full Text Available Amorphous poly(vinyl phenol (PVPh is introduced into poly(butylene succinate-co-butylene adipate/poly(l-lactic acid (PBSA/PLLA blends via solution casting. Fourier transform infrared spectroscopy (FTIR analysis verifies that intermolecular hydrogen bonding formed in PBSA/PVPh/PLLA blends. The miscibility between PBSA and PLLA is improved with PVPh incorporation as evidenced by approaching Tgs of the two components. When PVPh content reaches up to 50 wt %, the blend sample exhibits only one Tg, meaning complete miscibility between PBSA and PLLA. The improved miscibility of PBSA/PLLA blends is further confirmed by scanning electron microscope (SEM. Typical “see-island” phase separation structure for PBSA/PLLA blend transforms into homogenous phase structure for blend samples with 5 wt % PVPh and above. Non-isothermal crystallization analysis shows that the crystallization temperature and crystallization enthalpy of PBSA decrease with PVPh addition, and those of PLLA also show a decreasing trend. Isothermal crystallization rate of PBSA in blend samples distinctly decreases with PVPh incorporation, whereas that of PLLA in blend samples increases slightly with PVPh addition. Wide angle X-ray diffraction (WAXD analysis indicated that PLLA in blend samples remained partly crystallized, while PBSA turned into amorphous state with increasing PVPh contents.

  4. cis,cis-Muconic acid: separation and catalysis to bio-adipic acid for nylon-6,6 polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vardon, Derek R.; Rorrer, Nicholas A.; Salvachúa, 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.

    2016-01-01

    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

  5. Esters van tetrathioorthotinzuur

    NARCIS (Netherlands)

    Kramer, Jan

    1934-01-01

    Claesson claims to have obtained the tetraethyl ester of tetrathioorthostannic acid by shaking an aqueous solution of stannic chloride with ethylmercaptan and by distilling the heavy oily product. This could not be confirmed. A mixture of different products is formed, containing possibly among

  6. N-Heterocyclic Carbene Catalyzed [3+2] Cycloaddition of Enals with Masked Cinnamates for the Asymmetric One-Pot Synthesis of Adipic Acid Derivatives.

    Science.gov (United States)

    Chen, Xiang-Yu; Li, Sun; Sheng, He; Liu, Qiang; Jafari, Ehsan; von Essen, Carolina; Rissanen, Kari; Enders, Dieter

    2017-09-21

    A novel short entry to 3,4-disubstituted adipic acids has been developed by employing an asymmetric NHC-catalyzed [3+2] cycloaddition of enals with masked cinnammates in moderate to good yields and high stereoselectivities. The synthetic utility of the protocol was demonstrated by the basic conversion of the masked cyclopentanone intermediates to 3S,4S-disubstituted adipic acid precursors of pharmaceutically important gababutins. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Phosphate Esters, Thiophosphate Esters and Metal Thiophosphates as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    David W. Johnson

    2013-12-01

    Full Text Available Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. While their use has been extensive, a detailed knowledge of how they work has been a much more recent development. In this paper, the use of phosphate esters and thiophosphate esters as anti-wear or extreme pressure additives is reviewed with an emphasis on their mechanism of action. The review includes the use of alkyl phosphates, triaryl phosphates and metal containing thiophosphate esters. The mechanisms of these materials interacting with a range of iron and steel based bearing material are examined.

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

    Science.gov (United States)

    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.

  9. Preparation of polyol esters based on vegetable and animal fats.

    Science.gov (United States)

    Gryglewicz, S; Piechocki, W; Gryglewicz, G

    2003-03-01

    The possibility of using some natural fats: rapeseed oil, olive oil and lard, as starting material for the preparation of neopentyl glycol (NPG) and trimethylol propane (TMP) esters is reported. The syntheses of final products were performed by alcoholysis of fatty acid methyl esters, obtained from natural fats studied, with the appropriate polyhydric alcohol using calcium methoxide as a catalyst. The basic physicochemical properties of the NPG and TMP esters synthesized were the following: viscosity at 40 degrees C in the range of 13.5-37.6 cSt, pour point between -10.5 and -17.5 degrees C and very high viscosity indices, higher than 200. Generally, the esters of neopentyl alcohols were characterized by higher stability in thermo-oxidative conditions in comparison to native triglycerides. Due to the low content of polyunsaturated acids, the olive oil based esters showed the highest thermo-oxidative resistance. Also, methyl esters of fatty acids of lard would constitute a good raw material for the synthesis of lubricating oils, provided that their saturated acids content was lowered. This permits synthesis of NPG and TMP esters with a lower pour point (below -10 degrees C) than natural lard (+33 degrees C).

  10. Preparation and content determination of glipizide-loaded poly (β-amino esters) nanoparticles%载格列吡嗪的聚β-氨基酯纳米粒的制备及含量测定

    Institute of Scientific and Technical Information of China (English)

    胡亚男; 易涛; 许岩

    2013-01-01

    Objective To establish a preparation method of glipizide nanoparticles with the carrier of poly (β-amino esters) ,and to develop an HPLC method for the determination of glipizide. Methods The nanoparticles were prepared by using a modified double e-mulsion-solvent evaporation method and an improved self-emulsification-solvent diffusion method. The Easy Guard precolumn (10 mm×4. 6 mm) ,and ultimate xb-C18 column (250 mm×4. 6 mm,5μm] were used with 0. 1 mol · L-1 sodium dihydrogen phosphate (adjusted pH with 2. 0 mol · L-1 sodium hydroxide to 6. 00 ± 0. 05)-methanol (55 : 45) as the mobile phase. The flow rate was 1. 0 mL · min-1 and the wavelength of detection was set at 225 nm,the sample loaded was 20 μL and the column temperature was 35℃. Results The nanoparticles particle size prepared by the modified double emulsion-solvent evaporation method was smaller than that by the improved self-emulsification-solvent diffusion method. A good linear relationship was found between the concentration of glipizide and the peak area in the range of 0. 14-98. 88 mg·L-1 (r = 0. 9997) ,the average recovery was 100. 03% ,and average RSD was 1. 34%. Conclusions It was a better way to use the modified double emulsion-solvent evaporation method to prepare the nanoparticles,and the developed HPLC method is reliable and accurate to determine the content of glipizide.%目的 建立以聚β-氨基酯为载体的格列吡嗪纳米粒制备方法及其药物含量的高效液相色谱测定方法.方法 分别采用改良复乳-溶剂挥发法和改良自乳化-溶剂扩散法制备纳米粒,比较其性质差异;高效液相色谱条件为:Easy Guard预柱(10 mm×4.6 mm),Ultimate xb-C18柱(250 mm×4.6 mm,5 μm);流动相:0.1 mol·L-1NaH2PO4(用2.0 mol·L-1NaOH调pH为6.00±0.05)-甲醇(55∶45);流速:1.0 mL·min-1;检测波长:225 nm;进样量:20 μL;柱温:35 ℃.结果 改良复乳-溶剂挥发法制备纳米粒粒径较改良自乳化-溶剂扩

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

    OpenAIRE

    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...

  12. 新型可降解聚硅基酯的合成及性质研究%Synthesis and properties of new degradable poly (silyl ester)s

    Institute of Scientific and Technical Information of China (English)

    岳芸; 刘宗林; 王进喜

    2009-01-01

    主链中含有不稳定的硅酯键的聚硅基酯是一种新型的可降解聚合物.合成并研究了新型聚硅基酯即聚(己二酸四甲基二硅氧烷基硅基酯):首次利用熔融缩聚法使己二酸与1,1,3,3-四甲基二硅氧烷为单体合成了聚硅基酯,并用1H-NMR对该聚合物进行了结构表征,利用差示扫描量热(DSC)、热重分析(TGA)对其热力学性质进行了研究,利用凝胶渗透色谱(GPC)就分子量分布及降解性质进行了研究.%Polymers composed of silyl ester bonds in the main chain were investigated as a new class of degradable polymers. This paper first reported the synthesis and properties of degradable poly (silyl ester) s by 1,1,3,3-tetramethyldi-acetoxydisiloxanes with adipic acid.. The chemical structures of the polymer was confirmed by 1H-NMR. The properties of the poly(silyl ester)s was researched by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)and gel permeation chromatography(GPC).

  13. Classification of ester oils according to their Equivalent Alkane Carbon Number (EACN) and asymmetry of fish diagrams of C10E4/ester oil/water systems.

    Science.gov (United States)

    Ontiveros, Jesús F; Pierlot, Christel; Catté, Marianne; Molinier, Valérie; Pizzino, Aldo; Salager, Jean-Louis; Aubry, Jean-Marie

    2013-08-01

    The phase behavior of well-defined C10E4/ester oil/water systems versus temperature was investigated. Fifteen ester oils were studied and their Equivalent Alkane Carbon Numbers (EACNs) were determined from the so-called fish-tail temperature T* of the fish diagrams obtained with an equal weight amount of oil and water (f(w)=0.5). The influence of the chemical structure of linear monoester on EACN was quantitatively rationalized in terms of ester bonds position and total carbon number, and explained by the influence of these polar oils on the "effective" packing parameter of the interfacial surfactant, which takes into account its entire physicochemical environment. In order to compare the behaviors of typical mono-, di-, and triester oils, three fish diagrams were entirely plotted with isopropyl myristate, bis (2-ethylhexyl) adipate, and glycerol trioctanoate. When the number of ester bonds increases, a more pronounced asymmetry of the three-phase body of the fish diagram with respect to T* is observed. In this case, T* is much closer to the upper limit temperature Tu than to the lower limit temperature Tl of the three-phase zone. This asymmetry is suggested to be linked to an increased solubility of the surfactant in the oil phase, which decreases the surfactant availability for the interfacial pseudo-phase. As a consequence, the asymmetry depends on the water-oil ratio, and a method is proposed to determine the fw value at which T* is located at the mean value of Tu and Tl.

  14. Migration from plasticized films into foods. 1. Migration of di-(2-ethylhexyl)adipate from PVC films during home-use and microwave cooking.

    Science.gov (United States)

    Startin, J R; Sharman, M; Rose, M D; Parker, I; Mercer, A J; Castle, L; Gilbert, J

    1987-01-01

    Migration of di-(2-ethylhexyl)adipate (DEHA) into a diverse range of foods arising from the domestic use of plasticized PVC films has been determined using a stable isotope dilution GC/MS procedure. Aspects of home use reported in this study include the wrapping and covering of foods such as cheese, cooked meats, sandwiches, cakes, fresh fruit and vegetables; the use of films during food preparation such as marinading; covering during microwave reheating of previously prepared foods, and covering during microwave cooking. Contact between film and foods was for differing temperatures and times, representative of the range of conditions likely to be experienced in practice in the home. Migration increased with both the length of contact time and temperature of exposure, with the highest levels observed where there was a direct contact between the film and food, and where the latter had a high fat content on the contact surface. Highest levels of migration were observed for cheese, cooked meats, cakes and for microwave-cooked foods, whilst lower levels were observed for wrapping of unfilled sandwiches, fruit and vegetables (except avocado), and for food preparation including microwave reheating where there was covering of the food in a container but little or no direct contact.

  15. Heat Treatment Effects on the Mechanical Properties and Morphologies of Poly (Lactic Acid/Poly (Butylene Adipate-co-terephthalate Blends

    Directory of Open Access Journals (Sweden)

    Hsien-Tang Chiu

    2013-01-01

    Full Text Available In this study the relationships between mechanicals properties and morphology of the poly (lactic acid (PLA/poly (butylene adipate-co-terephthalate (PBAT blends with or without heat treatment were investigated. The differential scanning calorimetry (DSC analysis showed that blends have a two-phase structure indicating that they are immiscible. On the other hand, the PLA/PBAT (30/70 blend achieved the best tensile and impact strength because of its sea-island morphology, except for high PBAT content. The PLA/PBAT (70/30 and PLA/PBAT (50/50 blends showed irregular and directive-layer morphologies, in scanning electron microscopy (SEM analysis, producing a break cross-section with various fiber shapes. Both blends showed lower tensile strength and impact strength than the PLA/PBAT (30/70. After heat treatment, the PLA/PBAT blends showed high modulus of tensile and HDT because of a high degree of crystallization. The high degree of crystallization in the blends, which originated in the heat treatment, reduced their impact strength and elongation. However, the effect of high degree of crystallization on the PLA/PBAT (30/70 blend was small because of its sea-island morphology.

  16. Role of specific interfacial area in controlling properties of immiscible blends of biodegradable polylactide and poly[(butylene succinate)-co-adipate].

    Science.gov (United States)

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-12-01

    Binary blends of two biodegradable polymers: polylactide (PLA), which has high modulus and strength but is brittle, and poly[(butylene succinate)-co-adipate] (PBSA), which is flexible and tough, were prepared through batch melt mixing. The PLA/PBSA compositions were 100/0, 90/10, 70/30, 60/40, 50/50, 40/60, 30/70, 10/90, and 0/100. Fourier-transform infrared measurements revealed the absence of any chemical interaction between the two polymers, resulting in a phase-separated morphology as shown by scanning electron microscopy (SEM). SEM micrographs showed that PLA-rich blends had smaller droplet sizes when compared to the PBSA-rich blends, which got smaller with the reduction in PBSA content due to the differences in their melt viscosities. The interfacial area of PBSA droplets per unit volume of the blend reached a maximum in the 70PLA/30PBSA blend. Thermal stability and mechanical properties were not only affected by the composition of the blend, but also by the interfacial area between the two polymers. Through differential scanning calorimetry, it was shown that molten PBSA enhanced crystallization of PLA while the stiff PLA hindered cold crystallization of PBSA. Optimal synergies of properties between the two polymers were found in the 70PLA/30PBSA blend because of the maximum specific interfacial area of the PBSA droplets.

  17. Simultanneous determination of five groups content in acrylic acid 2-ethylhexyl ester reaction product by capillary gas chronmatography%气相色谱法测定丙烯酸2-乙基己酯反应产物中5组份的含量

    Institute of Scientific and Technical Information of China (English)

    陆君良; 陈科杰; 邵德贵

    2014-01-01

    采用毛细管气相色谱法同时测定丙烯酸2-乙基己酯反应产物中丙烯酸等5组份的含量。用面积归一法,测定各组份的含量,测定结果的相对标准偏差不大于1.5%(n=5),加标回收率为97.8%~102.5%。%Simultaneous determination of crylic acid etc five groups content in acrylic acid 2-ethylhexyl ester reaction product by capillary gas chronmatography.With the area normalization method ,determinayion of the content each component.The relative standart deviation of results were less than 1.5%(n=5) for five groups ,and recoreries were 97.8%~102.5%.

  18. Method of making alkyl esters

    Science.gov (United States)

    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.

  19. Regulated and unregulated emissions from a diesel engine fueled with diesel fuel blended with diethyl adipate

    Science.gov (United States)

    Zhu, Ruijun; Cheung, C. S.; Huang, Zuohua; Wang, Xibin

    2011-04-01

    Experiments were carried out on a four-cylinder direct-injection diesel engine operating on Euro V diesel fuel blended with diethyl adipate (DEA). The blended fuels contain 8.1%, 16.4%, 25% and 33.8% by volume fraction of DEA, corresponding to 3%, 6%, 9% and 12% by mass of oxygen in the blends. The engine performance and exhaust gas emissions of the different fuels were investigated at five engine loads at a steady speed of 1800 rev/min. The results indicated an increase of brake specific fuel consumption and brake thermal efficiency when the engine was fueled with the blended fuels. In comparison with diesel fuel, the blended fuels resulted in an increase in hydrocarbon (HC) and carbon monoxide (CO), but a decrease in particulate mass concentrations. The nitrogen oxides (NO x) emission experienced a slight variation among the test fuels. In regard to the unregulated gaseous emissions, formaldehyde and acetaldehyde increased, while 1,3-butadiene, ethene, ethyne, propylene and BTX (benzene, toluene and xylene) in general decreased. A diesel oxidation catalyst (DOC) was found to reduce significantly most of the investigated unregulated pollutants when the exhaust gas temperature was sufficiently high.

  20. Pyridoxine-dependent epilepsy with elevated urinary α-amino adipic semialdehyde in molybdenum cofactor deficiency.

    Science.gov (United States)

    Struys, Eduard Alexander; Nota, Benjamin; Bakkali, Abdellatif; Al Shahwan, Saad; Salomons, Gajja Sophi; Tabarki, Brahim

    2012-12-01

    α-Amino adipic semialdehyde (α-AASA) accumulates in body fluids from patients with pyridoxine-dependent epilepsy because of mutations in antiquitin (ALDH7A1) and serves as the biomarker for this condition. We have recently found that the urinary excretion of α-AASA was also increased in molybdenum cofactor and sulfite oxidase deficiencies. The seizures in pyridoxine-dependent epilepsy are caused by lowered cerebral levels of pyridoxal-5-phosphate (PLP), the bioactive form of pyridoxine (vitamin B(6)), which can be corrected by the supplementation of pyridoxine. The nonenzymatic trapping of PLP by the cyclic form of α-AASA is causative for the lowered cerebral PLP levels. We describe 2 siblings with clinically evident pyridoxine-responsive seizures associated with increased urinary excretion of α-AASA. Subsequent metabolic investigations revealed several metabolic abnormities, all indicative for molybdenum cofactor deficiency. Molecular investigations indeed revealed a known homozygous mutation in the MOCS2 gene. Based upon the clinically evident pyridoxine-responsive seizures in these 2 siblings, we recommend considering pyridoxine supplementation to patients affected with molybdenum cofactor or sulfite oxidase deficiencies.

  1. Novel microbial screen for detection of 1,4-butanediol, ethylene glycol, and adipic acid.

    Science.gov (United States)

    Stieglitz, B; Weimer, P J

    1985-03-01

    A novel microbial-screening procedure was developed for separate detection of 1,4-butanediol, ethylene glycol, and adipic acid, three commercially important oxychemicals potentially derivable from bacterial omega-oxidation of n-butanol, ethanol, and hexanoic acid, respectively. The screening method involved postproduction addition of one of several specific Pseudomonas strains which produce a soluble fluorescent pigment during growth on the product of interest. A mutation and selection procedure was developed for isolation of specific strains with phenotypes for growth and pigment production on the desired product (e.g., 1,4-butanediol), but not on its bioconversion substrate (e.g., n-butanol), common by-products (e.g., n-butyrate), or product isomers. Pigment production was growth associated and required cultivation of the screening strains under limiting Fe3+ concentrations. The pigments resembled well-characterized, iron-chelating siderophores produced by other fluorescent pseudomonads. The sensitivity of the assay for product accumulation was enhanced by (i) conducting the screening in microtiter dishes to permit examination of individual isolates of putative producers and to control product diffusion, (ii) using a wavelength cutoff filter to reduce background source light, and (iii) using adapted screening strains which grew at lower (0.3 mM) concentrations of test compounds. The potential utility of the method for detecting a variety of oxidative catabolic products is discussed.

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

    Science.gov (United States)

    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.

  3. Esters with water esters 2-c to 6-c

    CERN Document Server

    Getzen, F W; Hefter, G T; Maczynski, Andrzej

    1992-01-01

    This volume is the first of two devoted to esters and water. It includes solubility data for binary systems containing an ester and water up to the end of 1988. The critical evaluations were all prepared by one author and an introductory section has been included to elaborate the philosophy and methodology followed in the evaluations.

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

    Science.gov (United States)

    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.

  5. Migration of di(2-ethylhexyl) adipate and acetyltributyl citrate plasticizers from food-grade PVC film into sweetened sesame paste (halawa tehineh): kinetic and penetration study.

    Science.gov (United States)

    Goulas, Antonios E; Zygoura, Panagiota; Karatapanis, Andreas; Georgantelis, Dimitris; Kontominas, Michael G

    2007-04-01

    Food-grade polyvinyl chloride (PVC) cling-film containing 5.3% (w/w) di(2-ethylhexyl) adipate (DEHA) and 3.0% (w/w) acetyltributyl citrate (ATBC) plasticizers was used to wrap halawa tehineh (halva) samples. Samples were split into two groups and stored at 25+/-1 degrees C. One group was analyzed for DEHA and ATBC content at intervals between 0.5 and 240h of contact (kinetic study) and a second group was cut into slices (1.5mm thick) after 240h of halva/PVC contact and was analyzed for DEHA and ATBC content (penetration study). Determination of both plasticizers was performed using a direct gas chromatographic (GC) method after extraction of DEHA from halva samples. DEHA readily migrated into halva samples: the equilibrium amount of DEHA in halva (3.31mg/dm(2) film or 81.4mg/kg halva) corresponding to a loss of 54.7% (w/w) DEHA from PVC film. This value is slightly higher than the limit of 3mg/dm(2) of film surface set by the European Union for DEHA. The equilibrium amount of ATBC in halva was 1.46mg/dm(2) (36.1mg/kg) corresponding to a loss of 42.7% ATBC from PVC film. With regard to the penetration of both placticizers into halva samples, migration of DEHA was detectable up to the 7th slice beneath the surface of halva (total depth 10.5mm) while the migration of ATBC was detectable up to the 5th slice (total depth 7.5mm).

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-06-07

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Novel molecular anti-colorectalcancer conjugate:chlorambucil-adipic acid dihydrizide-glutamine.

    Science.gov (United States)

    Tabasi, Maryam Akhavan; Amanlou, Massoud; Siadat, Seyed Davar; Nourmohammadi, Zahra; Omoomi, Farnoor Davachi; Ebrahimi, Seyed Esmaeil Sadat; Aghasadeghi, Mohammad Reza; Rahimi, Pooneh; Pourhosseini, Sahar; Mehravi, Bita; Ardestani, Mehdi Shafiee

    2013-11-01

    Cancer is one of the most fatal diseases in the world and it has been years that finding new drugs and chemotherapeutic techniques with lowest side effects become one of the most important challenging matters needs really hard efforts. Chlorambucil (CBL), an ancient direct-acting alkylating anticancer agent, is commonly used for initial treatment of some kinds of cancers but the use of CBL is often limited because of the unpleasant side effects due to its lack of specificity for targeting cancer cells. In this research we tried to increase the specificity of CBL by producing a novel conjugate by using glutamine amino acid (Glut). Based on previous studies, poly amines and nitrogen compounds noticeably are used by cancer cells increasingly; therefore we decided to increase the efficiency and specificity of CBL by designing and producing a novel anti cancer conjugate using glutamine amino acid as an uptake enhancer, CBL, and Adipic acid Dihydrazide (ADH) as a spacer and linker. The biological tests were carried out on HT29 colorectal cancer cell line to evaluate its anticancer properties. Biological tests like MTT assay, finding IC50, evaluating the induced mechanism of the death of our novel CBL-Glutamine conjugate on HT29 cells, testing abnormal toxicity of this conjugate on mice in comparison with CBL drug were careid out. We found that not only CBL-Glutamine conjugate preserved its anti cancer property with regard to CBL drug, but also it represent lower abnormal toxicity in mice. Apoptosis was detected as its mechanism of the death. Our present study provides a promising strategy for targeting cancer cells using amino acids nano-conjugate drugs. The future perspectives have also been highlighted in continuing similar and relative researches.

  11. Di-(2-ethylhexyl) adipate in selected total diet food composite samples.

    Science.gov (United States)

    Cao, Xu-Liang; Zhao, Wendy; Churchill, Robin; Dabeka, Robert

    2013-11-01

    Polyvinyl chloride (PVC) food-wrapping films plasticized with di-(2-ethylhexyl) adipate (DEHA) are commonly used by grocery stores in Canada to rewrap meat, poultry, fish, cheese, and other foods. DEHA was assessed as part of the Government of Canada's Chemicals Management Plan. The main source of exposure for most age groups was expected to be food. Although the margin of exposure from food and beverages is considered to be adequately protective, the Government of Canada committed to performing targeted surveys of DEHA in foods and food packaging materials to better define Canadian exposure to DEHA through dietary intake. In order to determine whether more-comprehensive targeted surveys on DEHA in foods should be conducted, 26 food composite samples from the 2011 Canadian total diet study were selected and analyzed for DEHA using a method based on solvent and dispersive solid-phase extraction and gas chromatography-mass spectrometry. These 26 food composites include cheese, meat, poultry, fish, and fast foods, and PVC films were likely used in packaging the individual foods used to make the composites. DEHA was detected in most of the meat, poultry, and fish composite samples, with the highest concentration found in ground beef (11 μg/g), followed by beef steak (9.9 μg/g), freshwater fish (7.8 μg/g), poultry liver pâté (7.4 μg/g), fresh pork (6.9 μg/g), cold cuts and luncheon meats (2.8 μg/g), veal cutlets (2.1 μg/g), roast beef (1.3 μg/g), lamb (1.2 μg/g), and organ meats (0.20 μg/g). Targeted surveys should be conducted to investigate the presence of DEHA in various foods packaged with PVC films in more detail and provide updated occurrence data for accurate human exposure assessment.

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

    Science.gov (United States)

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

    2016-04-05

    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.

  13. New lipophilic tyrosyl esters. Comparative antioxidant evaluation with hydroxytyrosyl esters.

    Science.gov (United States)

    Mateos, Raquel; Trujillo, Mariana; Pereira-Caro, Gema; Madrona, Andrés; Cert, Arturo; Espartero, José Luis

    2008-11-26

    New lipophilic esters of tyrosol, a naturally occurring phenol with interesting biological properties, have been synthesized in good yields by a chemoselective procedure, using lipase from Candida antarctica or p-toluenesulfonic acid as catalysts. Their antioxidant activities have been evaluated by the Rancimat test in lipophilic food matrices, as well as by FRAP and ABTS assays in methanolic solutions, and compared with those of previously synthesized hydroxytyrosyl esters. Free tyrosol, hydroxytyrosol, butylhydroxytoluene, and alpha-tocopherol were used as standards. All methods used for the antioxidant activity evaluation emphasized the high influence of the ortho-diphenolic structure on the antioxidant capacity, tyrosol and its derivatives being less active than hydroxytyrosol and its analogues and even less than BHT and alpha-tocopherol. In addition, the Rancimat test revealed a lower activity for ester derivatives than for their respective reference compounds (HTy or Ty), in agreement with the polar paradox. On the other hand, FRAP and ABTS methods reported an opposite behavior between the synthetic esters and their respective references. Thus, hydroxytyrosyl esters were more active than HTy, whereas tyrosyl esters were less active than Ty. The length and nature of the acyl side chain did not seem to play an important role in the antioxidant activity of either the hydroxytyrosyl or tyrosyl ester series, since no significant differences were observed among them.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Radiation-Induced Crosslinking of Biodegradable Poly(Butylenes Adipate-Co-Terephthalate) Film With Various Crosslinking Agents

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Chanhee; Choi, Joonho; Kang, Dongwoo; Hwang, Intae; Choi, Jaehak; Nho, Youngchang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    In this research, electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate) (PBAT) in the presence of crosslinking agents was investigated. PBAT films containing different crosslinking agents were crosslinked by electron beam irradiation at various absorbed doses and the properties of the crosslinked PBAT films were characterized. The results of the crosslinking degree measurements revealed that 3 wt% triallyl isocyanurate was found to be optimal for the radiation crosslinking of PBAT. The thermal and mechanical properties of the crosslinked PBAT films were much improved whereas their biodegradability was reduced.

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

    DEFF Research Database (Denmark)

    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...... 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...

  17. The oxidation of dicarboxylic acid CoA esters via peroxisomal fatty acyl-CoA oxidase.

    Science.gov (United States)

    Poosch, M S; Yamazaki, R K

    1989-12-18

    Evidence supporting a common peroxisomal beta-oxidation pathway for the coenzyme A thioesters of medium-chain-length dicarboxylic acids (DCn-CoA) and monocarboxylic acids (MCn-CoA) has been obtained. Using the mono-CoA esters of dodecanedioic acid (DC12-CoA) and lauroyl-CoA (MC12-CoA) as substrates, parallel inductions of activities and parallel increases in specific activities during purification of peroxisomal fatty acyl-CoA oxidase (EC 1.3.99.3) from rat liver after di(2-ethylhexyl)phthalate treatment were seen. The purified enzyme was used for antiserum production in rabbits; antiserum specificity was verified by immunoblot analysis. Coincident losses of oxidase activities with MC12-CoA and DC12-CoA were found in immunotitration experiments with rat liver homogenates, supporting the hypothesis that peroxisomal fatty acyl-CoA oxidase is solely responsible for the oxidation of medium-chain length dicarboxylic acid substrates. Kinetic studies with purified enzyme using the mono-CoA esters of sebacic (DC10-CoA), suberic (DC8-CoA), and adipic (DC6-CoA) acids along with DC12-CoA revealed substrate inhibition. Although these substrates exhibited similar calculated Vmax values, with decreasing chain length, the combination of increasing Km values and decreasing substrate inhibition constant (Ki) caused the maximum obtainable velocity to decrease. These studies offer an explanation for the previously observed limit of the ability of peroxisomes to chain-shorten dicarboxylates and increased urinary excretion of adipic acid when peroxisomal oxidation of dicarboxylic acids is enhanced.

  18. Effects of blending alcohols with poultry fat methyl esters on cold flow properties

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Hem; Walker, Terry [Biosystems Engineering, 114 Biosystems Research Complex, Clemson University, Clemson, SC 29634 (United States); Moser, Bryan R. [United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL (United States); Toler, Joe [Applied Economics and Statistics, Clemson University, Clemson, SC (United States); Smith, William F. [Southeast Biodiesel, North Charleston, SC (United States)

    2010-10-15

    The low temperature operability, kinematic viscosity, and acid value of poultry fat methyl esters were improved with addition of ethanol, isopropanol, and butanol with increasing alcohol content. The flash point decreased and moisture content increased upon addition of alcohols to poultry fat methyl esters. The alcohol type did not result in a statistically significant difference in low temperature performance at similar blend ratios in poultry fat methyl esters. In addition, blends of ethanol in poultry fat methyl esters afforded the least viscous mixtures, whereas isopropanol and butanol blends were progressively more viscous, but still within specifications contained in ASTM D6751 and EN 14214. Blends of alcohols in poultry fat methyl esters resulted in failure of the flash point specifications found in ASTM D6751 and EN 14214. Flash points of butanol blends were superior to those of isopropanol and ethanol blends, with the 5 vol.% butanol blend exhibiting a flash point (57 C) superior to that of No. 2 diesel fuel (52 C). Blends of alcohols in poultry fat methyl esters resulted in an improvement in acid value with increasing content of alcohol. An increase in moisture content of biodiesel was observed with increasing alcohol content, with the effect being more pronounced in ethanol blends versus isopropanol and butanol blends. Finally, none of the alcohol-methyl ester samples exhibited a phase separation at sub-ambient temperatures. (author)

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

    Science.gov (United States)

    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.

  20. 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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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.

    Science.gov (United States)

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

    2012-02-16

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  3. In vitro release of clomipramine HCl and buprenorphine HCl from poly adipic anhydride (PAA) and poly trimethylene carbonate (PTMC) blends.

    Science.gov (United States)

    Dinarvand, Rassoul; Alimorad, Mohammed Massoud; Amanlou, Massoud; Akbari, Hamid

    2005-10-01

    Controlled drug-delivery technology is concerned with the systematic release of a pharmaceutical agent to maintain a therapeutic level of the drug in the body for modulated and/or prolonged periods of time. This may be achieved by incorporating the therapeutic agent into a degradable polymer vehicle, which releases the agent continuously as the matrix erodes. In this study, poly trimethylene carbonate (PTMC), an aliphatic polycarbonate, and poly adipic anhydride (PAA), an aliphatic polyanhydride, were synthesized via melt condensation and ring-opening polymerization of trimethylene carbonate and adipic acid, respectively. The release of clomipramine HCl and buprenorphine HCl from discs prepared with the use of PTMC-PAA blends in phosphate buffer (pH 7.4) are also described. Clomipramine HCl and buprenorphine HCl were both used as hydrophilic drug models. Theoretical treatment of the data with the Peppas model revealed that release of clomipramine HCl (5%) in devices containing 70% PTMC or more followed a Fickian diffusion model. However, the releases of buprenorphine HCl (5%) in the same devices were anomalous. For devices containing 50% and more PAA, surface erosion may play a significant role in the release of both molecules.

  4. Esters van tetrathioorthokiezelzuur en tetrathioorthogermaniumzuur

    NARCIS (Netherlands)

    Stienstra, Folkert Jans

    1934-01-01

    The germaniun tetrachloride required was prepared from the mineral germanite. For this a simpler method was elaborated. For the preparation of the esters of tetrathioorthosilicic acid and tetrathioorthogermanic acid, silicon tetrachloride and germanium tetrachloride were made to react with a

  5. Liquid Crystalline Esters of Dibenzophenazines

    Directory of Open Access Journals (Sweden)

    Kevin John Anthony Bozek

    2015-01-01

    Full Text Available A series of esters of 2,3,6,7-tetrakis(hexyloxydibenzo[a,c]phenazine-11-carboxylic acid was prepared in order to probe the effects of the ester groups on the liquid crystalline behavior. These compounds exhibit columnar hexagonal phases over broad temperature ranges. Variations in chain length, branching, terminal groups, and the presence of cyclic groups were found to modify transition temperatures without substantially destabilizing the mesophase range.

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

    OpenAIRE

    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...

  7. Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

    CSIR Research Space (South Africa)

    Neppalli, R

    2014-01-01

    Full Text Available In this work, composite polystyrene/titanium dioxide (PS/TiO(sub2)) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior...

  8. Effect of nanoclay on the nonisothermal crystallization of poly(propylene) and its blend with poly[(butylene succinate)-co-adipate

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2012-05-01

    Full Text Available The non-isothermal crystallization behaviour and kinetics of neat poly(propylene)(PP), PP/poly[(butylene succinate)-co-adipate] (PP/PBSA) blend and its composite with nanoclay was studied by differential scanning calorimetry at six different cooling...

  9. Effect of nanoclay loading on the thermal and mechanical properties of biodegradable Polylactide/Poly[(butylene succinate)- co-adipate] blend composites

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2012-04-01

    Full Text Available , Suprakas Sinha Ray and Rotimi Sadiku ABSTRACT:Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight...

  10. Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

    NARCIS (Netherlands)

    Neppalli, Ramesh; Causin, Valerio; Benetti, Edmondo M.; Ray, Suprakas Sinha; Esposito, Antonella; Wanjale, Santosh; Birajdar, Mallinath; Saiter, Jean-Marc; Marigo, Antonio

    2014-01-01

    In this work, composite polystyrene/titanium dioxide (PS/TiO2) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior of such materials were investigated, finding that, as a fu

  11. OPTIMASI PRODUKSI METIL ESTER SULFONAT DARI METIL ESTER MINYAK JELANTAH

    Directory of Open Access Journals (Sweden)

    Sri Hidayati

    2012-11-01

    Full Text Available OPTIMATION OF METHYL ESTER SULFONATES PRODUCTION FROM WASTE COOKING METHYL ESTER. An experiment of sulfonation process of methyl ester to produce methyl ester sulfonates (MES was caried out using waste palm methyl ester and sulfuric acid as sulfonating agent with variation of H2SO4 concentration (60% (K1, 70% (K2, dan 80% (K3 and sulfonation time (60 minute (L1, 75 minute (L2 and 90 minute (L3 using factorial on Randomized Complete Design Block. The experiment result showed the best sulfonation condition present in 80% H2SO4 concentration and sulfonation time of 90 minutes.  The best characteristic of MES is produced showed surface tension of 27.35 dyne/cm, emulsion stability of 89.44%, acid value of 17.72 mg KOH/g and interfacial tension of 0.0361 dyne/cm at MES concentration of 2% in 10,000 ppm salinity water. Sebuah penelitian tentang proses produksi metil ester sulfonat menggunakan minyak bekas kelapa sawit dilakukan dengan menggunakan H2SO4 sebagai agen pensulfonasi dengan variasi konsentrasi H2SO4 (60% (K1, 70% (K2, dan 80% (K3 dan lama sulfonasi (60 menit (L1, 75 menit (L2 and 90 menit (L3 dengan menggunakan faktorial dalam Rancangan Kelompok Teracak Lengkap. Hasil penelitian menunjukkan bahwa kondisi proses sulfonasi terbaik terdapat pada konsentrasi H2SO4 80% dan lama reaksi 90 menit. Karakteristik Metil Ester Sulfonat (MES terbaik yang dihasilkan memperlihatkan nilai tegangan permukaan 27,35 dyne/cm, stabilitas emulsi 89,44%, nilai bilangan asam antara 17,72 mg KOH/g dan nilai tegangan antar muka pada konsentrasi MES 2% di dalam air dengan salinitas 10.000 ppm yaitu 0,0361 dyne/cm.

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

    Science.gov (United States)

    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 ester chemiluminescence (light yield) is quite sensitive to the polarity of the micellar interface. In the current study, we report the synthesis of new acridinium ester labels with 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.

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

    Science.gov (United States)

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

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

  14. Phytosterol ester constituents affect micellar cholesterol solubility in model bile.

    Science.gov (United States)

    Brown, Andrew W; Hang, Jiliang; Dussault, Patrick H; Carr, Timothy P

    2010-09-01

    Plant sterols and stanols (phytosterols) and their esters are nutraceuticals that lower LDL cholesterol, but the mechanisms of action are not fully understood. We hypothesized that intact esters and simulated hydrolysis products of esters (phytosterols and fatty acids in equal ratios) would differentially affect the solubility of cholesterol in model bile mixed micelles in vitro. Sodium salts of glycine- and taurine-conjugated bile acids were sonicated with phosphatidylcholine and either sterol esters or combinations of sterols and fatty acids to determine the amount of cholesterol solubilized into micelles. Intact sterol esters did not solubilize into micelles, nor did they alter cholesterol solubility. However, free sterols and fatty acids altered cholesterol solubility independently (no interaction effect). Equal contents of cholesterol and either campesterol, stigmasterol, sitosterol, or stigmastanol (sitostanol) decreased cholesterol solubility in micelles by approximately 50% compared to no phytosterol present, with stigmasterol performing slightly better than sitosterol. Phytosterols competed with cholesterol in a dose-dependent manner, demonstrating a 1:1 M substitution of phytosterol for cholesterol in micelle preparations. Unsaturated fatty acids increased the micelle solubility of sterols as compared with saturated or no fatty acids. No differences were detected in the size of the model micelles. Together, these data indicate that stigmasterol combined with saturated fatty acids may be more effective at lowering cholesterol micelle solubility in vivo.

  15. Ethyl esters versus fermentative organoleptic defects in virgin olive oil.

    Science.gov (United States)

    Di Serio, Maria Gabriella; Giansante, Lucia; Di Loreto, Giuseppina; Faberi, Angelo; Ricchetti, Lorenzo; Di Giacinto, Luciana

    2017-03-15

    The quality and genuineness of extra-virgin olive oils (EVOOs) were assessed following the methods and parameters of EU Commission Regulation N° 2568/91/EEC and subsequent modifications, which also set specific limits for fatty-acid ethyl esters (FAEEs). This study included a subset of EVOOs from among 399 samples analysed as part of a monitoring study for FAEEs in EVOOs. The subset was subjected to statistical evaluation to quantify the relationships between FAEE content and sensory defects associated with fermentation: fusty/muddy sediment, musty/humid/earthy, and winey/vinegary. The use of multiple regression analysis demonstrates that FAEE content can be inferred as a function of the intensity of organoleptic defects for samples with high alkyl esters content. The intensity of the rancid defect negatively influences the accuracy of this model, because of underestimation of the fermentation defects that are also present. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Study of Non-Isothermal Crystallization Kinetics of Biodegradable Poly(ethylene adipate/SiO2 Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. R. Memarzadeh

    2013-09-01

    Full Text Available Poly(ethylene adipte and poly(ethylene adipate/silica nanocomposite (PEAd/SiO2 containing 3 wt. % SiO2  were prepared by an in situ method. The examinations on the non-isothermal crystallization kinetic behavior have been conducted by means of differential scanning calorimeter (DSC. The Avrami, Ozawa, and combined Avrami and Ozawa equations were applied to describe the crystallization kinetics and to determine the crystallization parameters of the prepared PEAd/SiO2 nanocomposites. It is found that the inclusion of the silica nanoparticles can accelerate the nucleation rate due to heterogeneous nucleation effect of silica on the polymer matrix. According to the obtained results, the combined Avrami and Ozawa equation shown that the better model for examination of this system.

  19. Clean Synthesis of Adipic Acid%清洁催化氧化合成己二酸

    Institute of Scientific and Technical Information of China (English)

    马祖福; 邓友全; 王坤; 陈静

    2001-01-01

    Synthesis of adipic acid by cyclohexene oxidation with 30 percent hydrogen peroxide in the presence of a novel peroxytungstate-organic complex catalyst without any organic solvents and phase-transfer catalyst can be performed with excellent yields and selectivities.The effect of organic ligand acidity and the amount of the catalyst on the oxidation reaction was investigated.%以新颖的过氧钨酸盐——有机酸配位络合物为催化剂,在无溶剂和无相转移剂的条件下,用30%的过氧化氢氧化环己烯合成己二酸,其收率可达93—95%。本文讨论了配位体种类及催化剂用量对反应的影响。

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

    Science.gov (United States)

    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.

  1. Orally administered glycidol and its fatty acid esters as well as 3-MCPD fatty acid esters are metabolized to 3-MCPD in the F344 rat.

    Science.gov (United States)

    Onami, Saeko; Cho, Young-Man; Toyoda, Takeshi; Akagi, Jun-ichi; Fujiwara, Satoshi; Ochiai, Ryosuke; Tsujino, Kazushige; Nishikawa, Akiyoshi; Ogawa, Kumiko

    2015-12-01

    IARC has classified glycidol and 3-monochloropropane-1,2-diol (3-MCPD) as group 2A and 2B, respectively. Their esters are generated in foodstuffs during processing and there are concerns that they may be hydrolyzed to the carcinogenic forms in vivo. Thus, we conducted two studies. In the first, we administered glycidol and 3-MCPD and associated esters (glycidol oleate: GO, glycidol linoleate: GL, 3-MCPD dipalmitate: CDP, 3-MCPD monopalmitate: CMP, 3-MCPD dioleate: CDO) to male F344 rats by single oral gavage. After 30 min, 3-MCPD was detected in serum from all groups. Glycidol was detected in serum from the rats given glycidol or GL and CDP and CDO in serum from rats given these compounds. In the second, we examined if metabolism occurs on simple reaction with rat intestinal contents (gastric, duodenal and cecal contents) from male F344 gpt delta rats. Newly produced 3-MCPD was detected in all gut contents incubated with the three 3-MCPD fatty acid esters and in gastric and duodenal contents incubated with glycidol and in duodenal and cecal contents incubated with GO. Although our observation was performed at 1 time point, the results showed that not only 3-MCPD esters but also glycidol and glycidol esters are metabolized into 3-MCPD in the rat.

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

    Science.gov (United States)

    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.

  3. Ester Tuiksoo otsib endiselt pesa / Paavo Kangur

    Index Scriptorium Estoniae

    Kangur, Paavo, 1966-

    2012-01-01

    Maadevahetuse protsessi raames süüdistati Ester Tuiksood, et põllumajandusministrina sai ta altkäemaksu Rävala 19 asunud korteri kasutamise eest. Ester Tuiksoo ja kinnisvaraeksperdi Tõnis Rüütli kommentaarid

  4. Synthesis of substituted 2-cyanoarylboronic esters

    DEFF Research Database (Denmark)

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael

    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....

  5. ANALYSIS OF COCONUT ETHYL ESTER (BIODIESEL) AND ...

    African Journals Online (AJOL)

    ANALYSIS OF COCONUT ETHYL ESTER (BIODIESEL) AND FOSSIL DIESEL BLENDING: PROPERTIES AND CORROSION CHARACTERISTICS. ... resulting coconut oil ethyl ester (COEE) was blended with fossil diesel (B0). ... Article Metrics.

  6. Ester Tuiksoo otsib endiselt pesa / Paavo Kangur

    Index Scriptorium Estoniae

    Kangur, Paavo, 1966-

    2012-01-01

    Maadevahetuse protsessi raames süüdistati Ester Tuiksood, et põllumajandusministrina sai ta altkäemaksu Rävala 19 asunud korteri kasutamise eest. Ester Tuiksoo ja kinnisvaraeksperdi Tõnis Rüütli kommentaarid

  7. Biocompatibility and degradation of aliphatic segmented poly(ester amide)s : in vitro and in vivo evaluation

    NARCIS (Netherlands)

    Lips, PAM; van Luyn, MJA; Chiellini, F; Brouwer, LA; Velthoen, IW; Dijkstra, PJ; Feijen, J

    2006-01-01

    Aliphatic segmented poly(ester amide)s, comprising a crystallizable amide phase and a flexible amorphous ester phase, were investigated for potential use in biomedical applications. By varying the amide content and the type of crystallizable amide segments, the polymer's thermal and mechanical prope

  8. Biocompatibility and degradation of aliphatic segmented poly(ester amide)s : in vitro and in vivo evaluation

    NARCIS (Netherlands)

    Lips, PAM; van Luyn, MJA; Chiellini, F; Brouwer, LA; Velthoen, IW; Dijkstra, PJ; Feijen, J

    2006-01-01

    Aliphatic segmented poly(ester amide)s, comprising a crystallizable amide phase and a flexible amorphous ester phase, were investigated for potential use in biomedical applications. By varying the amide content and the type of crystallizable amide segments, the polymer's thermal and mechanical prope

  9. Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers

    Science.gov (United States)

    Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

    2009-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.

  10. Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

    NARCIS (Netherlands)

    Tijsma, E.J.; Does, van der L.; Bantjes, A.; Vulic, I.

    1994-01-01

    The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal p

  11. Isolation, Fractionation, and Identification of Sucrose Esters from Various Oriental Tobaccos Employing Supercritical Fluids

    Directory of Open Access Journals (Sweden)

    Ashraf-Khorassani M

    2014-12-01

    Full Text Available Isolation, fractionation, and identification of sucrose esters from aged oriental tobacco employing supercritical fluids have been completed. Underivatized sucrose ester-rich extracts were obtained using supercritical CO2 at densities greater than 0.73 g/mL. Lower density CO2 provided extracts with notable amounts of tobacco derived material; yet, no detectable sucrose ester content. Preparative supercritical fluid chromatography (SFC provided for an additional purification of the sucrose ester-enriched fraction after column optimization. Structural assignments of the SFC fractions were facilitated using gas chromatography/mass spectrometry (GC/MS accompanied by N, O-bis(trimethylsilyltrifluoroacetamide-dimethylformamide (BSTFA-DMF derivatization of the free hydroxyl groups and high performance-liquid chromatography/mass spectrometry (HPLC/MS. From a relative quantitative perspective regardless of tobacco type, sucrose esters having an acetyl group on C6 of the glucose function (Group III were in higher concentration compared to both the concentration observed for sucrose ester of Group I (acetyl group on C3 of fructose and sucrose ester of Group II (no acetyl group on either glucose or fructose. Saturated fatty acid constituents were found to range from a maximum total of 18 carbons to a minimum total of 13 carbons. Unsaturated and isomeric fatty acid homologues were detected within the Group II sucrose ester.

  12. Application of Ester based Drilling Fluid for Shale Gas Drilling

    Science.gov (United States)

    Sauki, Arina; Safwan Zazarli Shah, Mohamad; Bakar, Wan Zairani Wan

    2015-05-01

    Water based mud is the most commonly used mud in drilling operation. However, it is ineffective when dealing with water-sensitive shale that can lead to shale hydration, consequently wellbore instability is compromised. The alternative way to deal with this kind of shale is using synthetic-based mud (SBM) or oil-based mud (OBM). OBM is the best option in terms of technical requirement. Nevertheless, it is toxic and will create environmental problems when it is discharged to onshore or offshore environment. SBM is safer than the OBM. The aim of this research is to formulate a drilling mud system that can carry out its essential functions for shale gas drilling to avoid borehole instability. Ester based SBM has been chosen for the mud formulation. The ester used is methyl-ester C12-C14 derived from palm oil. The best formulation of ester-based drilling fluid was selected by manipulating the oil-water ratio content in the mud which are 70/30, 80/20 and 90/10 respectively. The feasibility of using this mud for shale gas drilling was investigated by measuring the rheological properties, shale reactivity and toxicity of the mud and the results were compared with a few types of OBM and WBM. The best rheological performance can be seen at 80/20 oil-water ratio of ester based mud. The findings revealed that the rheological performance of ester based mud is comparable with the excellent performance of sarapar based OBM and about 80% better than the WBM in terms of fluid loss. Apart from that, it is less toxic than other types of OBM which can maintain 60% prawn's survival even after 96 hours exposure in 100,000 ppm of mud concentration in artificial seawater.

  13. Three-dimensional nonwoven scaffolds from a novel biodegradable poly(ester amide) for tissue engineering applications.

    Science.gov (United States)

    Hemmrich, Karsten; Salber, Jochen; Meersch, Melanie; Wiesemann, Ute; Gries, Thomas; Pallua, Norbert; Klee, Doris

    2008-01-01

    Biodegradable polyesters are established biomaterials in medicine due to their chemical characteristics and options for material processing. A main problem, however, is the release of acid degradation products during biodegradation with severe local pH-drops and inflammatory reactions. Polyesteramides, in contrast, show a less prominent pH-drop during degradation. In this study, we developed a simple, reproducible synthesis of the poly(ester amide) (PEA) type C starting from epsilon-caprolactame, 1,4-butanediol, and adipic acid in a one-batch two-step reaction and conducted the manufacturing of PEA-derived 3D textile scaffolds applicable for tissue engineering purposes. The thermal and mechanical properties of PEA-type C were analysed and the structural conformity of different batches was confirmed by NMR spectroscopy and size exclusion chromatography. The polymer was formed into nonwovens by textile manufacturing. Cytotoxicity tests and X-ray photoelectron spectroscopy (XPS) were used to analyze the effect of scaffold extraction before cell seeding. The manufactured carriers were seeded with human preadipocytes and examined for cellular proliferation and differentiation. The production of PEA type C successfully occurred via simultaneous ring-opening polymerization of epsilon-caprolactame and polycondensation with 1,4-butanediol and adipic acid at 250 degrees C under high-vacuum. Soxhlet extraction allowed optimal cleaning of nonwoven scaffolds. Extracted PEA-derived matrices were capable of allowing good adherence, proliferation, and differentiation of preadipocytes. These results are encouraging and guidance towards an optimally prepared nonwoven carrier applicable for clinical use.

  14. Esters van tetrathioorthokiezelzuur en tetrathioorthogermaniumzuur

    NARCIS (Netherlands)

    Stienstra, Folkert Jans

    1934-01-01

    The germaniun tetrachloride required was prepared from the mineral germanite. For this a simpler method was elaborated. For the preparation of the esters of tetrathioorthosilicic acid and tetrathioorthogermanic acid, silicon tetrachloride and germanium tetrachloride were made to react with a suspens

  15. 40 CFR 721.2805 - Acrylate ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  16. 40 CFR 721.537 - Organosilane ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Organosilane ester. 721.537 Section... § 721.537 Organosilane ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an organosilane ester (PMN P-96-1661/P-95-1654)...

  17. 40 CFR 721.3034 - Methylamine esters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methylamine esters. 721.3034 Section... Substances § 721.3034 Methylamine esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as methylamine esters (PMN P-94-982) is subject...

  18. Crystallographic Analysis of Analogous Silicon and Carbon Containing Di(Cyanate Ester)s and Tri(Cyanate Ester)s

    Science.gov (United States)

    2017-05-29

    lander are made from M55J/cyanate ester composites • The solar panel supports on the MESSENGER space probe use cyanate ester composite tie layers...Distribution Unlimited. PA# 17275 Cyanate Esters Around the Solar System 3 Images: courtesy NASA (public release) • The science decks on the Mars Phoenix

  19. Electrochemistry of polyamidoamine dendrimers ester gel electrolytes

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Formation and reduction of 3-monochloropropane-1,2-diol esters in peanut oil during physical refining.

    Science.gov (United States)

    Li, Chang; Li, Linyan; Jia, Hanbing; Wang, Yuting; Shen, Mingyue; Nie, Shaoping; Xie, Mingyong

    2016-05-15

    In the present study, lab-scale physical refining processes were investigated for their effects on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters. The potential precursors, partial acylglycerols and chlorines were determined before each refining step. 3-MCPD esters were not detected in degummed and bleached oil when the crude oils were extracted by solvent. While in the hot squeezed crude oils, 3-MCPD esters were detected with low amounts. 3-MCPD esters were generated with maximum values in 1-1.5h at a certain deodorizing temperature (220-260°C). Chlorine seemed to be more effective precursor than partial acylglycerol. By washing bleached oil before deodorization with ethanol solution, the precursors were removed partially and the content of 3-MCPD esters decreased to some extent accordingly. Diacetin was found to reduce 3-MCPD esters effectively.

  2. 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

    Directory of Open Access Journals (Sweden)

    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.

  3. Supramolecular architecture in a co-crystal of the N(7—H tautomeric form of N6-benzoyladenine with adipic acid (1/0.5

    Directory of Open Access Journals (Sweden)

    Robert Swinton Darious

    2016-06-01

    Full Text Available The asymmetric unit of the title co-crystal, C12H9N5O·0.5C6H10O4, consists of one molecule of N6-benzoyladenine (BA and one half-molecule of adipic acid (AA, the other half being generated by inversion symmetry. The dihedral angle between the adenine and phenyl ring planes is 26.71 (7°. The N6-benzoyladenine molecule crystallizes in the N(7—H tautomeric form with three non-protonated N atoms. This tautomeric form is stabilized by intramolecular N—H...O hydrogen bonding between the carbonyl (C=O group and the N(7—H hydrogen atom on the Hoogsteen face of the purine ring, forming an S(7 ring motif. The two carboxyl groups of adipic acid interact with the Watson–Crick face of the BA molecules through O—H...N and N—H...O hydrogen bonds, generating an R22(8 ring motif. The latter units are linked by N—H...N hydrogen bonds, forming layers parallel to (10-5. A weak C—H...O hydrogen bond is also present, linking adipic acid molecules in neighbouring layers, enclosing R22(10 ring motifs and forming a three-dimensional structure. C=O...π and C—H...π interactions are also present in the structure.

  4. Effect of sugar fatty acid esters on rumen fermentation in vitro

    OpenAIRE

    Wakita, M; Hoshino, S.

    1987-01-01

    1.The effect of sugar fatty acid esters (SFEs; currently used as food additives for human consumption) on rumen volatile fatty acids (VFA) and gas production was studied with sheep rumen contents in vitro.2. Some SFEs having monoester contents of more than 70% increased the molar proportion of propionate in conjunction with reduction in the acetate: propionate ratio when the individual SFE was added to rumen contents in a final concentration of 4 g/l. Laurate sugar ester was the most potent p...

  5. Processing and rheological characterization of poly(butylene adipate co-terephalate)/montmorillonite nanocomposites;Processamento e caracterizacao reologica de nanocompositos de poli(butileno adipato co-tereftalato)/montmorilonita

    Energy Technology Data Exchange (ETDEWEB)

    Beatrice, Cesar A.G.; Marini, Juliano; Bretas, Rosario E.S., E-mail: bretas@power.ufscar.b [Universidade Federal de Sao Carlos (PPGUFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Branciforti, Marcia C.; Favaro, Marcia M. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    The rheological steady state and the linear viscoelastic properties of poly(butylene adipate co-terephthalate) (PBAT) / nanoclay nanocomposites were investigated. For this study, nanocomposites of PBAT and a chemically modified montmorillonite (MMT) were prepared by melt blending in a Haake Rheomix 600p rheometer at 140 and 160 deg C. The concentration of nanoclay was 5wt%. The samples obtained were characterized by x-ray diffraction (WAXS) and rheological measurements in an ARES (Rheometric Scientific) and AR-G2 (TA) rheometers, both with parallel plates geometry. It was confirmed by WAXS that the platelets of the nanoclay were intercalated in all samples, as the discernible sharp reflection of the (001) clay's diffraction was found in the x-ray diffractions patterns. The storage moduli (G') and the loss moduli (G) of the nanocomposites increased with nanoclay content, at low frequencies. The presence of nanoclay caused these nanocomposites melts to have solid-like behaviors, which can be explained in terms of the development of a percolated network structure. (author)

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Methods of making alkyl esters

    Science.gov (United States)

    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.

  8. Di-(2-ethylhexyl) adipate and 20 phthalates in composite food samples from the 2013 Canadian Total Diet Study.

    Science.gov (United States)

    Cao, Xu-Liang; Zhao, Wendy; Dabeka, Robert

    2015-01-01

    A sensitive and selective GC-MS method was developed and used for simultaneous analysis of di-(2-ethylhexyl) adipate (DEHA) and 20 selected phthalates in the food samples from the 2013 Canadian Total Diet Study. At least one of the 21 target chemicals was detected in 141 of the 159 different food composite samples analysed. However, only seven of the 21 target chemicals were detected, with di-(2-ethylhexyl) phthalate (DEHP) and DEHA being detected most frequently, in 111 and 91 different food composite samples, respectively, followed by di-n-butyl phthalate (DBP) (n = 44), n-butyl benzyl phthalate (BBzP) (32), di-iso-butyl phthalate (DiBP) (27), di-ethyl phthalate (DEP) (3), and di-cyclohexyl phthalate (DCHP) (1). Levels of DEP (di-ethyl phthalate), DiBP, DBP, BBzP and DCHP were low, in general, with average concentrations of 9.63, 8.26, 23.2, 12.4 and 64.9 ng g(-1), respectively. Levels of DEHA and DEHP varied widely, ranging from 1.4 to 6010 ng g(-1) and from 14.4 to 714 ng g(-1), respectively. High levels of DEHA were found mainly in the composite samples where the individual food items used to prepare the composite were likely packaged in polyvinyl chloride (PVC) wrapping film, while the highest DEHP levels were found in the vegetable and fruit samples.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

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

    1997-01-01

    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 plasma...

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

    Index Scriptorium Estoniae

    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

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

    Index Scriptorium Estoniae

    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

  14. Method of making a cyanate ester foam

    Science.gov (United States)

    Celina, Mathias C.; Giron, Nicholas Henry

    2014-08-05

    A cyanate ester resin mixture with at least one cyanate ester resin, an isocyanate foaming resin, other co-curatives such as polyol or epoxy compounds, a surfactant, and a catalyst/water can react to form a foaming resin that can be cured at a temperature greater than 50.degree. C. to form a cyanate ester foam. The cyanate ester foam can be heated to a temperature greater than 400.degree. C. in a non-oxidative atmosphere to provide a carbonaceous char foam.

  15. Fumaric acid esters in dermatology

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

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

  16. Steroidal esters from Ferula sinkiangensis.

    Science.gov (United States)

    Li, Guangzhi; Li, Xiaojin; Cao, Li; Shen, Liangang; Zhu, Jun; Zhang, Jing; Wang, Junchi; Zhang, Lijing; Si, Jianyong

    2014-09-01

    Two new steroidal esters with an unusual framework, Sinkiangenorin A and B, a new organic acid glycoside, Sinkiangenorin C, and four known lignin compounds were isolated from the seeds of Ferula sinkiangensis. The structures of these compounds were established by spectroscopic analysis and single-crystal X-ray diffraction. All of the isolated compounds were tested against Hela, K562 and AGS human cancer cell lines. Sinkiangenorin C showed cytotoxic activity against AGS cells with an IC50 of 36.9 μM.

  17. Cobalt-catalyzed hydrogenation of esters to alcohols: unexpected reactivity trend indicates ester enolate intermediacy.

    Science.gov (United States)

    Srimani, Dipankar; Mukherjee, Arup; Goldberg, Alexander F G; Leitus, Gregory; Diskin-Posner, Yael; Shimon, Linda J W; Ben David, Yehoshoa; Milstein, David

    2015-10-12

    The atom-efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious-metal-based catalysts, with few exceptions. Presented here is the first cobalt-catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates.

  18. Morphology and mechanical properties of poly(butylene adipate-co-terephthalate)/potato starch blends in the presence of synthesized reactive compatibilizer or modified poly(butylene adipate-co-terephthalate).

    Science.gov (United States)

    Wei, Dafu; Wang, Hao; Xiao, Huining; Zheng, Anna; Yang, Yang

    2015-06-01

    The biodegradable poly(butylene adipate-co-terephthalate)(PBAT)/thermoplastic starch (TPS) composite has received considerable attention because of the environmental concerns raised by solid waste disposal. However, the application of PBAT/TPS blends was limited due to the poor mechanical properties originating from the incompatibility between PBAT and TPS. In this work, two approaches were developed to improve the mechanical properties of PBAT/TPS blends. One approach is to use compatibilizers, including the synthesized reactive compatibilizer - a styrene-maleic anhydride-glycidyl methacrylate (SMG) terpolymer, and the commercial compatibilizer (Joncryl-ADR-4368). The chemical structures of SMG were analyzed with (1)H NMR and FT-IR. The other approach is to use the modified PBAT (M-PBAT) to replace part of PBAT in the PBAT/TPS blends. M-PBATs with higher molecular weight were obtained via reactive extrusion of PBAT in the presence of a chain extender. The better dispersion of TPS in PBAT was observed in SEM images when using M-PBAT, leading to the higher tensile strength and elongation at break of PBAT/TPS blends. However, the elongation at break decreased in the presence of compatibilizer (SMG or 4368), though the tensile strength remained in a similar level or slightly higher. Overall, the tensile strength and the elongation at break of the resulting biodegradable PBAT/M-PBAT/TPS blends (TPS=40wt%) were above 27.0MPa and 500%, respectively, which is promising for various applications, including packaging and agricultural mulching films.

  19. Synthesis of insecticidal sucrose esters

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Comparative analysis of rubber seed methyl ester with other methyl ...

    African Journals Online (AJOL)

    Comparative analysis of rubber seed methyl ester with other methyl esters. ... In order to achieve a two-step transesterification process was developed to convert rubber seed oil to its methyl esters. The first step, acid catalyzed ... Article Metrics.

  1. Preparation of Hydroxypropyl Acetylated Distarch Adipates%羟丙基乙酰化双淀粉己二酸酯的制备

    Institute of Scientific and Technical Information of China (English)

    谭军华; 黄杨; 杨华

    2015-01-01

    Acetylated distarch adipates was prepared by cassava starch with adipic acetic mixed anhydride.It showed that the optimal parameters were initial starch slurry concentration 30%, pH 8, reaction time 1.5 h and mixed anhydride concentration 4.5%, respectively. The degree of hydroxypropyl substitution was 0.1264 , mixed anhydride molar substitution degree was 0.031.The properties of retrogradation, freeze-thaw stability and the degree of clarity were studied, retrogradation and freeze-thaw stability of acetylated distarch adipates had been greatly improved, and solubility and transparency were slightly lower than cassava starch.%采用已二酸与乙酸酐对木薯淀粉进行改性制备乙酰化双淀粉己二酸酯,得出最佳工艺条件为:淀粉乳初始浓度30%, pH 8,反应时间90 min,混合酸酐加入量4.5%,羟丙基取代度为0.1264,酯化取代度为0.031。考察了羟丙基乙酰化双淀粉己二酸酯的凝沉性、冻融稳定性和透明度,其中抗凝沉性和冻融稳定性都有了很大的提高,溶解度和透明度略微降低。

  2. Expanding ester biosynthesis in Escherichia coli.

    Science.gov (United States)

    Rodriguez, Gabriel M; Tashiro, Yohei; Atsumi, Shota

    2014-04-01

    To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l(-1)). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters.

  3. Esteróles en esponjas marinas

    Directory of Open Access Journals (Sweden)

    Carmenza Duque

    2009-07-01

    Full Text Available Esta revisión bibliográfica comprende la mayona del trabajo publicado hasta el momento sobre esteróles aislados de esponjas marinas. Estos esteróles comprenden compuestos desde Cig hasta C31 con estructuras convencionales y con estructuras novedosas (núcleo y/o cadena lateral no convencional.

  4. Preparation of Spirocyclic β-Proline Esters

    DEFF Research Database (Denmark)

    Fjelbye, Kasper; Marigo, Mauro; Clausen, Rasmus Prætorius

    2017-01-01

    A series of novel N-Bn-protected spirocyclic β-proline esters were prepared using [3+2] cycloaddition and subsequently converted into their corresponding aldehydes. In addition, two novel N-Cbz-protected spirocyclic β-proline esters were prepared using intramolecular cyclization starting from...

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    OpenAIRE

    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...

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

    Institute of Scientific and Technical Information of China (English)

    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。

  8. Comparative Studies on the Mechanical Properties of Nonwoven- and Woven-Flax-Fiber-Reinforced Poly(Butylene Adipate-Co-Terephthalate)-Based Composite Laminates

    Science.gov (United States)

    Phongam, N.; Dangtungee, R.; Siengchin, S.

    2015-03-01

    Textile biocomposites made from woven- and nonwoven-flax-fiber-reinforced poly(butylene adipate-co-terephthalate) (PBAT) were prepared by compression molding using the film stacking method, and their tensile strength and stiffness, flexural strength and modulus, and impact strength were determined experimentally. The PBAT-based composites were subjected to water absorption tests. The mechanical properties of pure PBAT and the textile composites were compared, and the influence of flax weave styles on the properties were evaluated. The biocomposite reinforced with 4 × 4-plain weave fibers showed the highest strength and stiffness compared with those of the other textile biocomposites and pure PBAT.

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

    Energy Technology Data Exchange (ETDEWEB)

    Echeverria, G. [LANADI e IFLP, Universidad Nacional de La Plata, CC67, 1900 La Plata (Argentina) and Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67, 1900 La Plata (Argentina)]. E-mail: geche@fisica.unlp.edu.ar; Punte, G. [LANADI e IFLP, Universidad Nacional de La Plata, CC67, 1900 La Plata (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67, 1900 La Plata (Argentina); Sives, F. [Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67, 1900 La Plata (Argentina); Brusau, E.V. [Area de Quimica General e Inorganica ' Dr. G. F. Puelles' , Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis (Argentina); Pedregosa, J.C. [Area de Quimica General e Inorganica ' Dr. G. F. Puelles' , Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis (Argentina); Narda, G.E. [Area de Quimica General e Inorganica ' Dr. G. F. Puelles' , Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis (Argentina); Ellena, J. [Instituto de Fisica Sao Carlos, Universidade de Sao Paulo, CP 369, CEP 13560-970, Sao Carlos, SP (Brazil)

    2004-12-31

    An AC susceptibility study of [Nd{sub 2}(O{sub 2}C(CH{sub 2}){sub 4}CO{sub 2}){sub 3}(H{sub 2}O){sub 2}] (1) obtained from a solution at ambient conditions was performed in the range 14-320K. An ordering transition, T{sub C}=280(2)K, not related to a structural phase transition, a ferromagnetic like Curie-Weiss behavior above T{sub C}, an antiferromagnetic like dependence of {chi}'-1 at the lowest temperatures and a non-linear thermal dependence of {chi}'-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.

  10. Ethanolysis of rapeseed oil - distribution of ethyl esters, glycerides and glycerol between ester and glycerol phases.

    Science.gov (United States)

    Cernoch, Michal; Hájek, Martin; Skopal, Frantisek

    2010-04-01

    The distribution of ethyl esters, triglycerides, diglycerides, monoglycerides, and glycerol between the ester and glycerol phase was investigated after the ethanolysis of rapeseed oil at various reaction conditions. The determination of these substances in the ester and glycerol phases was carried out by the GC method. The amount of ethyl esters in the glycerol phase was unexpectedly high and therefore the possibility of the reduction of this amount was investigated. The distribution coefficients and the weight distributions of each investigated substance were calculated and compared mutually. The distribution coefficients between the ester and glycerol phase increase in this sequence: glycerol, monoglycerides, diglycerides, ethyl esters, and triglycerides. Soaps and monoglycerides in the reaction mixture cause a worse separation of ethyl esters from the reaction mixture. The existence of a non-separable reaction mixture was observed also, and its composition was determined.

  11. Anticholinesterase activity of fluorochloronitroacetic acid esters

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu.Ya.; Brel, V.K. Martynov, I.V.

    1984-11-01

    Results are presented from pharmacologic and biochemical experiments leading to the conclusion that fluorochloronitroacetic acid esters have anticholinesterase activity. Since the esters caused muscular weakness in mice, experiments were performed on isolated tissue preparation. The biochemical experiments consisted of finding the biomolecular constants of irreversible inhibition of acetylcholinesterase by the esters, using acetylcholinesterase from human erythrocytes, as well as horse serum cholinesterase. The ethyl and n-propyl esters of halogen nitroacetic acid were used in all experiments. It was found that the propyl ester caused an increase in the force of individual contractions in the isolated muscle specimens, plus an inability of the muscle to retain tetanus. The substances were determined to have an anticholinesterase effect. The mechanism of cholinesterase inhibition is not yet known. It is probable that the substances acylate the serine hydroxyl of the esterase center of the cholinestersase. 7 references, 1 figure.

  12. Divergence in the enzymatic activities of a tomato and Solanum pennellii alcohol acyltransferase impacts fruit volatile ester composition.

    Science.gov (United States)

    Goulet, Charles; Kamiyoshihara, Yusuke; Lam, Nghi B; Richard, Théo; Taylor, Mark G; Tieman, Denise M; Klee, Harry J

    2015-01-01

    Tomato fruits accumulate a diverse set of volatiles including multiple esters. The content of ester volatiles is relatively low in tomato fruits (Solanum lycopersicum) and far more abundant in the closely related species Solanum pennellii. There are also qualitative variations in ester content between the two species. We have previously shown that high expression of a non-specific esterase is critical for the low overall ester content of S. lycopersicum fruit relative to S. pennellii fruit. Here, we show that qualitative differences in ester composition are the consequence of divergence in enzymatic activity of a ripening-related alcohol acyltransferase (AAT1). The S. pennellii AAT1 is more efficient than the tomato AAT1 for all the alcohols tested. The two enzymes have differences in their substrate preferences that explain the variations observed in the volatiles. The results illustrate how two related species have evolved to precisely adjust their volatile content by modulating the balance of the synthesis and degradation of esters.

  13. 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

    DEFF Research Database (Denmark)

    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....... Operating conditions were maintained constant but the adipate and dissolved oxygen concentrations (DOC) were varied separately in a range from I to 37.5 g l(-1) and from 2% to 125% air saturation (%AS), respectively. The total beta-lactams specific productivity, r(p) (total) was not significantly changed...

  14. Organophosphate ester flame retardant-induced acute intoxications in dogs.

    Science.gov (United States)

    Lehner, Andreas F; Samsing, Francisca; Rumbeiha, Wilson K

    2010-12-01

    Flame retardants have wide industrial applications and are incorporated into articles found in automobiles and home environments, including seat cushions. These compounds differ widely chemically and in their toxic potential. We report here two cases involving dogs following ingestion of car seat cushions impregnated with organophosphate ester fire retardants. Two case reports are presented. Two adult American Pit Bull dogs were presented at an emergency clinic with acute signs of central nervous system excitation including seizures. The most severely affected dog died 15 min after presentation, while the less affected dog fully recovered following treatment. In the second case, both a German Shepherd and a Rottweiler were found dead in the morning after they were left in a car overnight. A comprehensive toxicological analysis of samples from both cases revealed the presence of significant amounts (>2 ppm) of tris(2-chloroethyl)phosphate (TCEP) in stomach contents. This compound is a known inducer of epileptic seizures. Some other structurally related organophosphate ester compounds were found, and their role in the acute intoxications reported here is not known and remains to be determined. This is the first report linking acute deaths in dogs to the ingestion of car seat cushions found to contain large amounts of TCEP, an organophosphate ester compound. It is highly likely that this compound caused death through its known seizure-inducing activity.

  15. Antifungal properties of halofumarate esters.

    Science.gov (United States)

    Gershon, H; Shanks, L

    1978-04-01

    Alkyl esters (C1--C4) of the four halofumaric acids were tested for antifungal activity against Candida albicans, Aspergillus niger, Mucor mucedo, and Trichophyton mentagrophytes at pH 5.6 and 7.0 in the absence and presence of 10% beef serum in Sabouraud dextrose agar. The most toxic compound to each organism was: C. albicans, ethyl iodofumarate (0.054 mmole/liter); A. niger, methyl bromofumarate (0.090 mmole/liter); M. mucedo, methyl fluorofumarate (0.037 mmole/liter); and T. mentagrophytes, ethyl iodofumarate (0.020 mmole/liter). The order of overall activity of the six most toxic compounds was: ethyl iodofumarate greater than ethyl chlorofumarate greater than methyl iodofumarate = methyl bromofumarate greater than methyl chlorofumarate greater than bromofumarate.

  16. Enzymatic synthesis and application of fatty acid ascorbyl esters

    Directory of Open Access Journals (Sweden)

    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

  17. The solubility measurements of sodium dicarboxylate salts; sodium oxalate, malonate, succinate, glutarate, and adipate in water from T = (279.15 to 358.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Rozaini, Mohd Zul Helmi [School of Environmental Science, University of East Anglia, Norwich, Norfolk NR4 7TJ (United Kingdom); Department of Chemical Sciences, Faculty of Science and Technology, University Malaysia Terengganu, 21030 Kuala Terengganu (Malaysia)], E-mail: zulhelmi@umt.edu.my; Brimblecombe, Peter [School of Environmental Science, University of East Anglia, Norwich, Norfolk NR4 7TJ (United Kingdom)

    2009-09-15

    The solubility measurements of sodium dicarboxylate salts; sodium oxalate, malonate, succinate, glutarate, and adipate in water at temperatures from (278.15 to 358.15 K) were determined. The molar enthalpies of solution at T = 298.15 K were derived: {delta}{sub sol}H{sub m} (m = 2.11 mol . kg{sup -1}) = 13.86 kJ . mol{sup -1} for sodium oxalate; {delta}{sub sol}H{sub m} (m = 3.99 mol . kg{sup -1}) = 14.83 kJ . mol{sup -1} for sodium malonate; {delta}{sub sol}H{sub m} (m = 2.45 mol . kg{sup -1}) = 14.83 kJ . mol{sup -1} for sodium succinate; {delta}{sub sol}H{sub m} (m = 4.53 mol . kg{sup -1}) = 16.55 kJ . mol{sup -1} for sodium glutarate, and {delta}{sub sol}H{sub m} (m = 3.52 mol . kg{sup -1}) = 15.70 kJ . mol{sup -1} for sodium adipate. The solubility value exhibits a prominent odd-even effect with respect to terms with odd number of sodium dicarboxylate carbon numbers showing much higher solubility. This odd-even effect may have implications for the relative abundance of these compounds in industrial applications and also in the atmospheric aerosols.

  18. Simultaneous analysis of phthalates, adipate and polycyclic aromatic hydrocarbons in edible oils using isotope dilution-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Oh, Min-Seok; Lee, Seon-Hwa; Moon, Myeong Hee; Lee, Dong Soo; Park, Hyun-Mee

    2014-01-01

    A method for simultaneous determination of 12 priority phthalates, adipate and polycyclic aromatic hydrocarbons (PAHs) in edible oils by isotope dilution-gas chromatography-mass spectrometry (ID-GC-MS) was developed for fast, accurate and trace analysis. The extraction and clean-up procedures were optimised, and using stable isotope-labelled internal standards for each analyte, relative standard deviations (RSDs) of 0.92-10.6% and spiked sample recoveries of 80.6-97.8% were obtained. Limits of detection for PAHs were in the range of 0.15-0.77 µg/kg and those for phthalates were in the range of 4.6-10.0 µg/kg. The calibration curves exhibited good linearities with regression coefficients of R(2) ≥ 0.99. Twelve edible oils were examined to evaluate the efficiency of this method. Among the 12 analytes, dibutyl phthalates (DBP), diethylhexyl phthalates (DEHP), diethylhexyl adipate (DEHA), benzo[a]anthracene (B[a]A), chrysene (Chry) and benzo[b]fluoranthene (B[b]F) were detected in the range of 1.17-806 µg/kg.

  19. Stability of ketoprofen-dextran ester prodrugs in homogenates of various segments of pig GI tract

    DEFF Research Database (Denmark)

    Larsen, C.; Jensen, Bodil Hamborg; Olesen, H. P.

    1991-01-01

    Initial velocities of ketoprofen formation from ketoprofen-dextran ester prodrugs incubated in homogenates of various segments of the pig GI-tract were determined. Enzyme-mediated drug release was found in caecum and colon homogenates with their contents, whereas release rates in the stomach...

  20. Environmentally Friendly Bio-Based Vinyl Ester Resins for Military Composite Structures

    Science.gov (United States)

    2008-12-01

    Protection Agency, 2003: National Emission Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production, Federal Register, 68...G.R., 2007: Fatty acid-based vinyl ester composites with low hazardous air pollutant contents, J. of BioBased Matl. and BioEnergy, 1, 409-416

  1. New ester alkaloids from lupins (genus lupinus).

    Science.gov (United States)

    Mühlbauer, P; Witte, L; Wink, M

    1988-06-01

    Esters of 13-hydroxylupanine and 4-hydroxylupanine with acetic, propionic, butyric, isobutyric, valeric, isovaleric, tiglic, benzoic, and TRANS-cinnamic acid have been synthesized and characterized by capillary gas-liquid chromatography and mass spectrometry (EI-MS, CI-MS). In LUPINUS POLYPHYLLUS, L. ALBUS, L. ANGUSTIFOLIUS, and L. MUTABILIS we could identify new ester alkaloids (e.g. 13-propyloxylupanine, 13-butyryloxylupanine, 13-isobutyryloxylupanine, and 4-tigloyloxylupanine) besides the known esters, i.e. 13-acetoxylupanine, 13-isovaleroyloxylupanine, 13-angeloyloxylupanine, 13-tigloyloxylupanine, 13-benzoyloxylupanine, 13- CIS-cinnamoyloxylupanine nine, and 13- TRANS-cinnamoyloxylupanine.

  2. Cold Flow Properties of Fatty Esters

    Directory of Open Access Journals (Sweden)

    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.

  3. Synthesis of Trimethylolpropane Esters of Calophyllum Methyl Esters : Effect of Temperature and Molar Ratio

    Directory of Open Access Journals (Sweden)

    Yeti Widyawati

    2014-12-01

    Full Text Available Trimethylolpropane esters were synthesized by transesterification of calophyllum methyl esters and trimethylolpropane using a calcium oxide as the catalyst. The results showed that the optimal reaction conditions (temperature: 130 0C, reaction time: 5 h, reactant molar ratio: 3.9:1, catalyst amount 3%w/w, and formed  trimethylolpropane ester of 79.0% were obtained. The basic physicochemical properties of the trimethylolpropane esters were the following : kinematic viscosities of 56.40 cSt and 8.8 cSt at 40 0C and 100 0C,  viscosity index 193, flash point 218 0C and pour point -3 0C. So Methyl esters of fatty acids of would callophylum  methyl ester is good raw material for the synthesis of lubricating oils.

  4. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyglycerol esters of fatty acids. 172.854 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol esters, may be safely used in food in...

  5. Determination of Lutein and Zeaxanthin Esters and Their Geometric Isomers in Carotenoid Ester Concentrates Used as Ingredients in Nutritional Supplements: Validation of a Combined Spectrophotometric-HPLC Method.

    Science.gov (United States)

    Lombeida, Wagner O; Rubio, Fernando; Levy, Luis W

    2016-11-01

    A combined spectrophotometric-LC method is described for the determination of total lutein and zeaxanthin ester content in carotenoid ester concentrates, including their main geometrical isomers. The concept of composite-specific absorbance is introduced for this purpose. The method is applicable to carotenoid ester concentrates used as ingredients in oil suspensions and dosage forms. The sample is dissolved in a hexane-2-propanol mixture (95 + 5, v/v) for spectrophotometric measurement at a maximum absorption of ~445 nm. Subsequently, in parallel, a sample is saponified and chromatographed on a normal-phase HPLC column to determine the relative percentage profile of the main geometrical isomers of both carotenoid esters. This, in turn, is used to calculate the composite-specific absorbance of the sample for the final calculation of results. The method, which solely uses reference standards to validate chromatographic conditions, avoids the common error of applying the specific absorbance of only the trans isomer for the calculation of total carotenoid content when cis isomers are present.

  6. Ester Tuiksoo - riigi peakokk / Peeter Kuimet

    Index Scriptorium Estoniae

    Kuimet, Peeter

    2007-01-01

    Põllumajandusminister Ester Tuiksoo eelseisvast vastuvõtust Estonias, jopede kinkimisest maaelu arengukava väljatöötamisega seotud inimestele. Minister Tuiksoo kohta tehtud kriitikast. SDE esimehe Ivari Padari arvamus. Lisa: Tuiksoo jopedest ja tassidest

  7. Space-Qualifiable Cyanate Ester Elastomer Project

    Data.gov (United States)

    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...

  8. Space-Qualifiable Cyanate Ester Elastomer Project

    Data.gov (United States)

    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 structures...

  9. Ester Tuiksoo - riigi peakokk / Peeter Kuimet

    Index Scriptorium Estoniae

    Kuimet, Peeter

    2007-01-01

    Põllumajandusminister Ester Tuiksoo eelseisvast vastuvõtust Estonias, jopede kinkimisest maaelu arengukava väljatöötamisega seotud inimestele. Minister Tuiksoo kohta tehtud kriitikast. SDE esimehe Ivari Padari arvamus. Lisa: Tuiksoo jopedest ja tassidest

  10. Pharmacokinetics of Ketorolac Pentyl Ester, a Novel Ester Derivative of Ketorolac, in Rabbits

    Directory of Open Access Journals (Sweden)

    Jann-Inn Tzeng

    2005-08-01

    Full Text Available Ketorolac is a potent nonsteroidal anti-inflammatory drug. Recently, a novel ester of ketorolac, ketorolac pentyl ester, was synthesized. When prepared in injectable oil, the new agent demonstrated a long duration of action. Ketorolac pentyl ester was synthesized using a prodrug design by esterification of ketorolac, and appeared to be a prodrug of ketorolac in vivo, which needed to be confirmed. The aim of the present study was to establish the prodrug's pharmacokinetics in vivo, and to confirm whether or not ketorolac pentyl ester was a prodrug of ketorolac. Pharmacokinetic profiles of intravenous ketorolac and its pentyl ester on an equal-molar basis in six rabbits were evaluated. A high-performance liquid chromatographic method was used to determine the plasma concentrations of ketorolac and its pentyl ester. We found that the plasma concentrations of ketorolac pentyl ester declined rapidly after injection and so did the conversion of ketorolac pentyl ester to ketorolac. Also, the conversion of ketorolac was proved complete when compared with intravenous ketorolac under an equi-molar basis. In conclusion, this in vivo pharmacokinetic study confirmed that keterolac pentyl ester was a prodrug of keterolac.

  11. 己二酸生产中的废气净化技术及其影响因素%Decontamination technology of exhaust gas in adipic acid production and the influence factors

    Institute of Scientific and Technical Information of China (English)

    周禹君; 李多春

    2012-01-01

    以辽阳石化公司硝酸氧化醇酮制备己二酸装置为研究对象,研究了己二酸生产中废气的净化技术及废气消减过程中的影响因素.NO,NO2的净化采用水吸收法,以尾气中NOx含量和回收硝酸浓度为主要考察指标,设计了四因素三水平的正交试验,通过试验得出的优化工艺条件为:喷淋水流量7m3/h、补充空气量900 m3/h、吸收温度14℃、吸收压力0.155 MPa,尾气中NOx体积分数为420×10-6,回收硝酸质量分数35%.N2O的净化采用催化分解法,并对影响其分解效果的3个因素进行了研究.结果表明,入口温度应随催化剂活性减弱逐渐升高,进气浓度最好维持在11.0%~11.2%,原料气中含水不利于催化分解.%It will release a great deal of exhaust gas which contain NO, NO2 and N2O in the process of adipic acid produc-tion by oxidation of alcohol ketone with nitric acid. The decontamination technology of the exhaust gas and the influence factors are studied based on the adipic acid plant in Liaoyang Petrochemical Company. NO and NO2 gas are absorbed by water. Setting the content of NOT in the exhaust gas and the concentration of reclaimed nitric acid as main targets, the 4 factors and 3 levels orthogonal test is carried out. The optimum conditions of NOX absorbing is achieved as follows: absorbed water capacity is 7 m3/h, inlet air quantity is 900 m3/rw operation temperature is 14 ℃ and operation pressure is 0. 155 MPa. Under above condi-tions, the volume fraction of NOX in the exhaust gas is 420×10-6 and the mass fraction of reclaimed nitric acid is 35%. N2O is decomposed by catalyst, and three factors which influence the N2O decomposition is discussed. The results show that the inlet air temperature should rise with the activation of the catalyst reducing, the concentration of N2O in inlet air between 11. 0%-11. 2% is better, and the containing moisture is not good for decomposition.

  12. Rapid Output Growth of Special Acrylic Esters

    Institute of Scientific and Technical Information of China (English)

    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.

  13. New daucane esters from Ferula tingitana.

    Science.gov (United States)

    Miski, M; Mabry, T J

    1986-01-01

    In addition to the three known daucane esters (2,3,8) and one phenylpropanoid (9), the petroleum ether extract of the roots of Ferula tingitana yielded four new daucane esters: 14-p-anisoyloxy-dauc-4,8-diene (1), acetyltingitanol (4), acetyldesoxodehydrolaserpitine (5), and 4-beta-hydroxy-6-alpha-p-hydroxybenzoyloxy-10-alpha-angeloyloxy dauc-8-ene (6). A possible biogenetic pathway for 1,5-cis- and 1,5-trans-daucanes is presented.

  14. Conversion of carbohydrates to levulinic acid esters

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to the field of converting carbohydrates into levulinic acid, a platform chemical for many chemical end products. More specifically the invention relates to a method for converting carbohydrates such as mono-, di- or polysaccharides, obtained from for example biomass...... production into a suitable levulinic acid ester in the presence of a zeolite or zeotype catalyst and a suitable alcohol, and the ester may be further converted into levulinic acid if desired....

  15. Synthesis of a new energetic nitrate ester

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Preparation and study of release kinetics of rosin pentaerythritol ester microcapsules.

    Science.gov (United States)

    Sheorey, D S; Dorle, A K

    1994-01-01

    Rosin was esterified with pentaerythritol and intermediate reaction products with different acid values were isolated. Microcapsules containing sulphadiazine were prepared by a solvent evaporation technique using these esters as wall materials. The microcapsules were evaluated for their size, drug content, and release characteristics in simulated gastric and intestinal fluids. The microcapsule size increased as the acid value of the ester decreased. The release of the drug was studied by using first-order, Higuchi and Hixon-Crowell cube root models. The release mechanism of the microcapsules is discussed.

  17. PREPARATION AND PROPERTIES OF FUMED SILICA/CYANATE ESTER NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Elhussein A.Taha; Jun-tao Wu; Kai Gao; Lin Guo

    2012-01-01

    Fumed silica/bisphenol A dicyanate ester (BADCy) nanocomposites were prepared by introducing different contents of nano-sized fumed SiO2 into the BADCy matrix.Two different average primary particle diameters of 12 and 40 nm were chosen.Dibutyltindilaurate (DBTDL) catalyst was chosen to catalyze the cyanate ester group into triazine group via cyclotrimerization reaction.The SEM micrographs indicated that the fumed SiO2 particles were homogeneously dispersed in the poly(bisphenol A dicyanate) matrix by means of ultrasonic treatment and the addition of a coupling agent.The FTIR spectroscopy shows that,not only DBTDL catalyzes the polymerization reaction but also-OH groups of the SiO2 particles surface help the catalyst for the complete polymerization of BADCy monomer.The thermal stability of the cured BADCy can be improved by adequate addition of fumed SiO2.A slight increase in the dielectric constant and dielectric loss values were identified by testing the dielectric properties of the prepared nanocomposite samples.By increasing the SiO2 content,there was a slight increasing in the thermal conductivity values of the tested samples.The obtained results proved that the fumed silica/BADCy nanocomposites had good thermal and dielectrical properties and can be used in many applications such as in the thermal insulation field.

  18. Synthesis and characterization of active ester-functionalized polypyrrole-silica nanoparticles: application to the covalent attachment of proteins.

    Science.gov (United States)

    Azioune, Ammar; Slimane, Amel Ben; Hamou, Lobnat Ait; Pleuvy, Anne; Chehimi, Mohamed M; Perruchot, Christian; Armes, Steven P

    2004-04-13

    Novel ester-functionalized polypyrrole-silica nanocomposite particles were prepared by oxidative copolymerization of pyrrole and N-succinimidyl ester pyrrole (50/50% initial concentrations), using FeCl3 in the presence of ultrafine silica nanoparticles (20 nm diameter). The N-succinimidyl ester pyrrole monomer was prepared in aqueous solution using 1-(2-carboxyethylpyrrole) and N-hydroxysuccinimide in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The resulting nanocomposites (N-succinimidyl ester polypyrrole-silica) are raspberry-shaped agglomerates of silica sol particles "glued" together by the insoluble poly(pyrrole-co-N-succinimidyl pyrrole). The N-succinimidyl ester polypyrrole-silica particles were characterized in terms of their size, density, copolymer content, and polydispersity. Scanning electron microscopy and disk centrifuge sedimentometry confirmed that the nanocomposite particles had narrow size distributions. X-ray photoelectron spectroscopy analysis indicated a silica-rich surface and a high surface concentration of N-succinimidyl ester groups. These nanoparticles exhibited good long-term dispersion stability. The chemical stability of the ester functions in aqueous media after several weeks of storage was monitored by FTIR spectroscopy. The functionalized nanocomposites were tested as bioadsorbents of human serum albumin (HSA). The very high amount of immobilized HSA determined by UV-visible spectroscopy is believed to be due to covalent binding. Incubation of the HSA-grafted nanocomposite with anti-HSA resulted in immediate flocculation, an indication that they are alternative candidates for visual diagnostic assays.

  19. Online LC-GC analysis of free sterols/stanols and intact steryl/stanyl esters in cereals.

    Science.gov (United States)

    Esche, Rebecca; Scholz, Birgit; Engel, Karl-Heinz

    2013-11-20

    The suitability of online liquid chromatography-gas chromatography for the analysis of free sterols/stanols, steryl/stanyl fatty acid esters, and trans-steryl/stanyl ferulic acid esters in cereals is demonstrated. The silylated lipid extracts were fractionated via liquid chromatography on a normal phase, and the fractions containing the sterol classes were transferred online to the gas chromatograph for the analysis of their individual compositions. The study provides for the first time data on free sterols/stanols and intact steryl/stanyl esters in sweet corn, popcorn, and proso millet. Sweet corn revealed the highest contents of free sterols/stanols and steryl/stanyl fatty acid esters, and popcorn, in turn, the highest amounts of trans-steryl/stanyl ferulic acid esters. The distribution patterns of the proso millet samples revealed pronounced differences from those of sweet corn and popcorn as they particularly exhibited high proportions of free cholesterol and cholesteryl fatty acid esters. Furthermore, no trans-steryl/stanyl ferulic acid esters could be detected.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  2. Sinapate esters in brassicaceous plants: biochemistry, molecular biology, evolution and metabolic engineering.

    Science.gov (United States)

    Milkowski, Carsten; Strack, Dieter

    2010-06-01

    Brassicaceous plants are characterized by a pronounced metabolic flux toward sinapate, produced by the shikimate/phenylpropanoid pathway, which is converted into a broad spectrum of O-ester conjugates. The abundant sinapate esters in Brassica napus and Arabidopsis thaliana reflect a well-known metabolic network, including UDP-glucose:sinapate glucosyltransferase (SGT), sinapoylglucose:choline sinapoyltransferase (SCT), sinapoylglucose:L-malate sinapoyltransferase (SMT) and sinapoylcholine (sinapine) esterase (SCE). 1-O-Sinapoylglucose, produced by SGT during seed development, is converted to sinapine by SCT and hydrolyzed by SCE in germinating seeds. The released sinapate feeds via sinapoylglucose into the biosynthesis of sinapoylmalate in the seedlings catalyzed by SMT. Sinapoylmalate is involved in protecting the leaves against the deleterious effects of UV-B radiation. Sinapine might function as storage vehicle for ready supply of choline for phosphatidylcholine biosynthesis in young seedlings. The antinutritive character of sinapine and related sinapate esters hamper the use of the valuable seed protein of the oilseed crop B. napus for animal feed and human nutrition. Due to limited variation in seed sinapine content within the assortment of B. napus cultivars, low sinapine lines cannot be generated by conventional breeding giving rise to genetic engineering of sinapate ester metabolism as a promising means. In this article we review the progress made throughout the last decade in identification of genes involved in sinapate ester metabolism and characterization of the encoded enzymes. Based on gene structures and enzyme recruitment, evolution of sinapate ester metabolism is discussed. Strategies of targeted metabolic engineering, designed to generate low-sinapate ester lines of B. napus, are evaluated.

  3. Carotenoids in a Corynebacterineae, Gordonia terrae AIST-1: carotenoid glucosyl mycoloyl esters.

    Science.gov (United States)

    Takaichi, Shinichi; Maoka, Takashi; Akimoto, Naoshige; Carmona, Marvelisa L; Yamaoka, Yukiho

    2008-10-01

    We isolated a strain of Corynebacterineae from surface seawater from the Inland Sea of Japan. This strain, AIST-1, was determined to be a strain of Gordonia terrae based on its 16S rRNA gene sequence. The colony was red-colored, and the pigments were identified to be carotenoid derivatives. The structures of two major carotenoids were (2'S)-deoxymyxol 1'-glucoside, a dihydroxyl derivative of gamma-carotene with 12 conjugated double bonds, and (2'S)-4-ketodeoxymyxol 1'-glucoside. Their glucosyl acyl esters and mycoloyl esters were also identified. While these carotenoid moieties have been found in only a few other bacteria, the carotenoid mycoloyl esters are novel carotenoid derivatives. The type strain of G. terrae NBRC 10016T also contained the same carotenoids, but the composition of the two carotenoid glucosides was low and the total carotenoid content was less than one tenth of that of strain AIST-1.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Copper-catalyzed cascade reactions of α,β-unsaturated esters with keto esters

    OpenAIRE

    Zhengning Li; Chongnian Wang; Zengchang Li

    2015-01-01

    A copper-catalyzed cascade reaction of α,β-unsaturated esters with keto esters is reported. It features a copper-catalyzed reductive aldolization followed by a lactonization. This method provides a facile approach to prepare γ-carboxymethyl-γ-lactones and δ-carboxymethyl-δ-lactones under mild reaction conditions.

  6. Detection of testosterone esters in blood.

    Science.gov (United States)

    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. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Physiological characterization of lipid accumulation and in vivo ester formation in Gordonia sp. KTR9.

    Science.gov (United States)

    Eberly, Jed O; Ringelberg, David B; Indest, Karl J

    2013-02-01

    Previous work has demonstrated the feasibility of in vivo biodiesel synthesis in Escherichia coli, however, ethyl ester formation was dependent on an external fatty acid feedstock. In contrast to E. coli, actinomycetes may be ideal organisms for direct biodiesel synthesis because of their capacity to synthesize high levels of triacylglcerides (TAGs). In this study, we investigated the physiology and associated TAG accumulation along with the in vivo ability to catalyze ester formation from exogenous short chain alcohol sources in Gordonia sp. KTR9, a strain that possesses a large number of genes dedicated to fatty acid and lipid biosynthesis. Total lipid fatty acids content increased by 75 % and TAG content increased by 50 % under nitrogen starvation conditions in strain KTR9. Strain KTR9 tolerated the exogenous addition of up to 4 % methanol, 4 % ethanol and 2 % propanol in the media. Increasing alcohol concentrations resulted in a decrease in the degree of saturation of recovered fatty acid alcohol esters and a slight increase in the fatty acid chain length. A linear dose dependency in fatty alcohol ester synthesis was observed in the presence of 0.5-2 % methanol and ethanol compared to control KTR9 strains grown in the absence of alcohols. An inspection of the KTR9 genome revealed the presence of several putative wax ester synthase/acyl-coenzyme A : diacylglycerol acyltransferase (WS/DGAT) enzymes, encoded by atf gene homologs, that may catalyze the in vivo synthesis of fatty acid esters from short chain alcohols. Collectively, these results indicate that Gordonia sp. KTR9 may be a suitable actinomycete host strain for in vivo biodiesel synthesis.

  8. Production and biological function of volatile esters in Saccharomyces cerevisiae

    Science.gov (United States)

    Saerens, Sofie M. G.; Delvaux, Freddy R.; Verstrepen, Kevin J.; Thevelein, Johan M.

    2010-01-01

    Summary The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of fermented alcoholic beverages like beer, wine and sake. As esters are synthesized in yeast via several complex metabolic pathways, there is a need to gain a clear understanding of ester metabolism and its regulation. The individual genes involved, their functions and regulatory mechanisms have to be identified. In alcoholic beverages, there are two important groups of esters: the acetate esters and the medium‐chain fatty acid (MCFA) ethyl esters. For acetate ester synthesis, the genes involved have already been cloned and characterized. Also the biochemical pathways and the regulation of acetate ester synthesis are well defined. With respect to the molecular basis of MCFA ethyl ester synthesis, however, significant progress has only recently been made. Next to the characterization of the biochemical pathways and regulation of ester synthesis, a new and more important question arises: what is the advantage for yeast to produce these esters? Several hypotheses have been proposed in the past, but none was satisfactorily. This paper reviews the current hypotheses of ester synthesis in yeast in relation to the complex regulation of the alcohol acetyl transferases and the different factors that allow ester formation to be controlled during fermentation. PMID:21255318

  9. Physical and thermo-mechanical properties of bionano reinforced poly(butylene adipate-co-terephthalate, hemp/CNF/Ag-NPs composites

    Directory of Open Access Journals (Sweden)

    Harikrishnan Pulikkalparambil

    2017-07-01

    Full Text Available A facile approach to prepare bionanocomposites of poly(butylene adipate-co-terephthalate (PBAT is reported in this paper. The effect of different wt% of hemp/Sihemp, carbon nanofiber (CNF and silver nanoparticle (Ag-NPs on the density, water absorption, melting and crystallization behavior, thermal stability, mechanical properties and morphology was investigated. The density of the composites was reduced except for Ag-NPs reinforced nanocomposites while diffusion coefficient and maximum water absorption were decreased for Sihemp reinforced composites making it a suitable material to replace conventional polymers. Significant improvement in tensile strength (TS and tensile modulus (TM was observed for the PBAT/Sihemp composites. For CNF and Ag-NPs reinforced nanocomposites, mechanical properties were retained at lower filler concentration. But as the concentration increased, there was a tendency for the nanofillers to agglomerate, which resulted in a reduction in mechanical properties.

  10. Pyridoxine-dependent seizures caused by alpha amino adipic semialdehyde dehydrogenase deficiency: the first polish case with confirmed biochemical and molecular pathology.

    Science.gov (United States)

    Kaczorowska, Magdalena; Kmiec, Tomasz; Jakobs, Cornelis; Kacinski, Marek; Kroczka, Slawomir; Salomons, Gajja S; Struys, Eduard A; Jozwiak, Sergiusz

    2008-12-01

    Pyridoxine-dependent seizures are a rare condition recognized when numerous seizures respond to pyridoxine treatment and recur on pyridoxine withdrawal. For decades the diagnosis was confirmed only with pyridoxine treatment withdrawal trial. Recently described biochemical and molecular pathology improved the diagnostic process for those cases in which seizures are caused by alpha amino adipic semialdehyde dehydrogenase deficiency. This article presents a girl with recurrent status epilepticus episodes resistant to phenobarbital and phenytoin and partly responding to midazolam. Eventually the seizures were completely controlled with pyridoxine; however, due to the severe condition of this child when seizing, no trial of withdrawal has been performed. The diagnosis of pyridoxine-dependent seizures was confirmed with biochemical and molecular testing revealing elevated alpha-AASA excretion and the presence of 2 different mutations in the antiquitin ( ALDH7A1) gene. Due to the availability of reliable laboratory testing, confirmation of the diagnosis was made without the life-threatening trial of pyridoxine withdrawal.

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

    Science.gov (United States)

    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.

  12. Curdlan ester derivatives: synthesis, structure, and properties.

    Science.gov (United States)

    Marubayashi, Hironori; Yukinaka, Kazuyori; Enomoto-Rogers, Yukiko; Takemura, Akio; Iwata, Tadahisa

    2014-03-15

    A series of ester derivatives of curdlan, which is a β-(1 → 3)-D-glucan extracellularly produced by microorganism, with varying alkyl chain lengths (C2-C12) were synthesized by the heterogeneous reaction using trifluoroacetic anhydride. As a result, high-molecular-weight (Mw ≥ 6 × 10(5)) and fully-acylated curdlan was obtained with relatively high yield (>70%). Thermal stability of curdlan was greatly improved by esterification. Crystallization was observed for curdlan esters with C2-C6 side chains. Both Tg (170 → 50 °C) and Tm (290 → 170 °C) of curdlan esters decreased with increasing the side-chain length. By the increase in the side-chain carbon number, curdlan esters showed lower Young's modulus and tensile strength, and larger elongation at break. Thus, material properties of curdlan esters can be controlled by changing the side-chain length. It was found that the increase of the side-chain length resulted in the decrease of crystallinity and the change of crystal structures.

  13. 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

    Institute of Scientific and Technical Information of China (English)

    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。

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

    Institute of Scientific and Technical Information of China (English)

    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. Zero birefringence films of pullulan ester derivatives

    Science.gov (United States)

    Danjo, Takahiro; Enomoto, Yukiko; Shimada, Hikaru; Nobukawa, Shogo; Yamaguchi, Masayuki; Iwata, Tadahisa

    2017-04-01

    High-performance films with almost zero-birefringence and zero-wavelength dispersion were succeeded to prepare from pullulan esters derivatives (PLEs) without any additives. Optical transmittance analysis, birefringence measurement of PLE cast film and hot stretched films, and infrared dichroism analysis were conducted to characterize optical properties of PLE films comparing with cellulose triacetate which is commercially used as low-birefringence in optical devices. The aims of this study, characterization of optical properties of pullulan esters, can develop a deep understanding of the fundamental knowing and applicability of polysaccharides. Accordingly, authors believe this paper will open the gate for researches in the application of polysaccharides.

  16. Affinity labelling enzymes with esters of aromatic sulfonic acids

    Science.gov (United States)

    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. Chiral extraction of ketoprofen enantiomers with chiral selector tartaric esters

    Institute of Scientific and Technical Information of China (English)

    ZHOU Dan; LIU Jia-jia; TANG Ke-wen; HUANG Ke-long

    2007-01-01

    Distribution behavior of ketoprofen enantiomers was examined in methanol aqueous and organic solvent mixture containing tartaric esters. The influence of length of alkyl chain of tartaric esters, concentration of L-tartaric esters and methanol aqueous, kind of organic solvent on partition ratio and separation factors was investigated. The results show that L-tartaric and D-tartaric esters have different chiral recognition abilities. S-ketoprofen is easily extracted by L-tartaric esters, and R-ketoprofen is easily extracted by D-tartaric esters. L-tartaric esters form more stable diastereomeric complexes with S-enantiomer than that with R-enantiomer. This distribution behavior is consistent with chiral recognition mechanism. With the increase of the concentration of tartaric ester from 0 to 0.3 mol/L, partition coefficient K and separation factor α increase. Also, the kind of organic solvent and the concentration of the methanol aqueous have significant influence on K and α.

  18. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    Effect of Sucrose Esters on the Physicochemical Properties of Wheat Starch. ... Methods: Sucrose ester was mixed with wheat starch extracted from normal soft wheat cultivars and heated. Change in starch properties arising ... Article Metrics.

  19. Biocatalytic synthesis and antioxidant capacities of ascorbyl esters ...

    African Journals Online (AJOL)

    Biocatalytic synthesis and antioxidant capacities of ascorbyl esters by Novozym 435 in tert-butanol ... Novozym 435 was used to catalyze the synthesis of fatty acid (FA) ascorbyl esters in tert-butanol using methyl palmitate, ... Article Metrics.

  20. Phthalate ester plasticizers in freshwater systems of Venda, South ...

    African Journals Online (AJOL)

    Phthalate ester plasticizers in freshwater systems of Venda, South Africa and potential health effects. ... Abstract. Phthalate ester plasticizers were determined in rivers and dams of the Venda region, South Africa. Liquid-liquid ... Article Metrics.

  1. Evaluation of the levels of phthalate ester plasticizers in surface ...

    African Journals Online (AJOL)

    Evaluation of the levels of phthalate ester plasticizers in surface water of Ethiope River System, Delta State, Nigeria. ... studies of the river. Keywords: phthalates, acid esters, plasticizers, Ethiope River, surface water, pollution ... Article Metrics.

  2. Study of shellac glycerol esters as microencapsulating materials.

    Science.gov (United States)

    Labhasetwar, V D; Puranik, P K; Dorle, A K

    1989-01-01

    Shellac esters were prepared by heating shellac with glycerol and intermediate reaction products were withdrawn. Salicyclic acid granules were encapsulated using a 20 per cent w/v alcoholic solution of shellac and shellac esters. The coated microcapsules were evaluated for moisture absorption, flow properties, and dissolution studies. The drug release from coated granules was seen to depend upon the acid value of the esters. Results indicate that shellac esters could be better encapsulating material than shellac in sustained release formulation.

  3. Production of novel "functional oil" rich in diglycerides and phytosterol esters with "one-pot" enzymatic transesterification.

    Science.gov (United States)

    Zheng, Ming-Ming; Huang, Qing; Huang, Feng-Hong; Guo, Ping-Mei; Xiang, Xia; Deng, Qian-Chun; Li, Wen-Lin; Wan, Chu-Yun; Zheng, Chang

    2014-06-04

    Diglycerides and phytosterol esters are two important functional lipids. Phytosterol esters mixed with dietary diglyceride could not only influence body weight but also prevent or reverse insulin resistance and hyperlipidemia. In this study, a kind of novel "functional oil" rich in both diglycerides and phytosterol esters was prepared with "one-pot" enzymatic transesterification. First, lipase AYS (Candida rugosa) was immobilized on the porous cross-linked polystyrene resin beads (NKA) via hydrophobic interaction. The resulting immobilized AYS showed much better transesterification activity and thermal stability to freeways. On the basis of the excellent biocatalyst prepared, a method for high-efficiency enzymatic esterification of phytosterols with different triglycerides to produce corresponding functional oils rich in both diglycerides and phytosterol esters was developed. Four functional oils rich in both diglycerides and phytosterol esters with conversions >92.1% and controllable fatty acid composition were obtained under the optimized conditions: 80 mmol/L phytosterols, 160 mmol/L triglycerides, and 25 mg/mL AYS@NKA at 180 rpm and 50 °C for 12 h in hexane. The prepared functional oil possessed low acid value (≤1.0 mgKOH/g), peroxide value (≤2.1 mmol/kg), and conjugated diene value (≤1.96 mmol/kg) and high diglyceride and phytosterol ester contents (≥10.4 and ≥20.2%, respectively). All of the characteristics favored the wide application of the functional oil in different fields of functional food.

  4. Measurement and Correlation for Solubility of Adipic Acid in Several Solvents%己二酸在几种有机溶剂中溶解度的测定与关联

    Institute of Scientific and Technical Information of China (English)

    樊丽华; 马沛生; 相政乐

    2007-01-01

    Using a laser detecting system, solubility data were measured for adipic acid dissolved in six pure solvents, namely, cyclohexanone, cyclohexanol, acetic acid, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethylsulfoxide at the temperature range from 293.15K to 353.15K. All these data were regressed by λh, NRTL,Wilson, and the modified Wilson models. For the study of six, λh, NRTL, and the modified Wilson models were found to provide an accurate mathematical representation of the experimental results, with overall average absolute relative deviations between measured and calculated values as 1.74%, 2.06%, and 3.06%, respectively. The resultsshowed that the λh model is the most suitable for description of the solid-liquid equilibrium containing adipic acid.

  5. Acrylic Acid and Esters Will Be Oversupply

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Avocado and olive oil methyl esters

    Science.gov (United States)

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

  7. Complexes with Methionine Methyl Ester. Equilibria and ...

    African Journals Online (AJOL)

    NICO

    Methionine methyl ester forms 1:1 and 1:2 complexes with diorganotin(IV). The corresponding ... coordination compounds R2SnX2L2 is controlled by the nature of. R, the leaving ... nitrate were obtained from Acros Organics. Carbonate-free.

  8. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  9. Saliva-catalyzed hydrolysis of a ketobemidone ester prodrug

    DEFF Research Database (Denmark)

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

    1992-01-01

    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...

  10. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated benzyl ester acrylate... Specific Chemical Substances § 721.329 Halogenated benzyl ester acrylate (generic). (a) Chemical substance... halogenated benzyl ester acrylate (PMN P-90-1527) is subject to reporting under this section for...

  11. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nitrobenzoic acid octyl ester. 721... Substances § 721.1732 Nitrobenzoic acid octyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as nitrobenzoic acid octyl ester (PMN...

  12. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  13. 40 CFR 721.2925 - Brominated aromatic ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated aromatic ester. 721.2925... Substances § 721.2925 Brominated aromatic ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a brominated aromatic ester (PMN...

  14. 40 CFR 721.5310 - Neononanoic acid, ethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Neononanoic acid, ethenyl ester. 721... Substances § 721.5310 Neononanoic acid, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as neononanoic acid, ethenyl ester (PMN...

  15. 40 CFR 721.2825 - Alkyl ester (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  16. 21 CFR 172.735 - Glycerol ester of rosin.

    Science.gov (United States)

    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... CONSUMPTION Other Specific Usage Additives § 172.735 Glycerol ester of rosin. Glycerol ester of wood...

  17. 40 CFR 721.3085 - Brominated phthalate ester.

    Science.gov (United States)

    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)...

  18. 40 CFR 721.3140 - Vinyl epoxy ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under...

  19. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Science.gov (United States)

    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...

  20. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexadecanoic acid, ethenyl ester. 721... Substances § 721.4158 Hexadecanoic acid, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexadecanoic acid, ethenyl ester (PMN...

  1. 40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanedioic acid, diethenyl ester. 721... Substances § 721.4215 Hexanedioic acid, diethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexanedioic acid, diethenyl ester (PMN...

  2. 40 CFR 721.2121 - Thiosubstituted carbonate ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Thiosubstituted carbonate ester... Specific Chemical Substances § 721.2121 Thiosubstituted carbonate ester (generic). (a) Chemical substance... Thiosubstituted carbonate ester (PMN P-99-0654) is subject to reporting under this section for the significant...

  3. 75 FR 71556 - Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption

    Science.gov (United States)

    2010-11-24

    ... AGENCY 40 CFR Part 180 Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of polyoxyalkylated glycerol fatty acid esters; the... ethylene oxide or propylene oxide, also known as polyoxyalkylated glycerol fatty acid esters, when used as...

  4. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Science.gov (United States)

    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 ester...

  5. 21 CFR 556.240 - Estradiol and related esters.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Estradiol and related esters. 556.240 Section 556... Tolerances for Residues of New Animal Drugs § 556.240 Estradiol and related esters. No residues of estradiol, resulting from the use of estradiol or any of the related esters, are permitted in excess of the following...

  6. An overview of the properties of fatty acid alkyl esters

    Science.gov (United States)

    Fatty acid alkyl esters of plant oils, especially in the form of methyl esters, have numerous applications with fuel use having received the most attention in recent times due to the potential high volume. Various properties imparted by neat fatty acid alkyl esters have been shown to influence fuel ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

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

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

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

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

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

    Science.gov (United States)

    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.

  11. Nanoporous Polymer Films of Cyanate Ester Resins Designed by Using Ionic Liquids as Porogens

    Science.gov (United States)

    Fainleib, Alexander; Vashchuk, Alina; Starostenko, Olga; Grigoryeva, Olga; Rogalsky, Sergiy; Nguyen, Thi-Thanh-Tam; Grande, Daniel

    2017-02-01

    Novel nanoporous film materials of thermostable cyanate ester resins (CERs) were generated by polycyclotrimerization of dicyanate ester of bisphenol E in the presence of varying amounts (from 20 to 40 wt%) of an ionic liquid (IL), i.e., 1-heptylpyridinium tetrafluoroborate, followed by its quantitative extraction after complete CER network formation. The completion of CER formation and IL extraction was assessed using gel fraction content determination, FTIR, 1H NMR, and energy-dispersive X-ray spectroscopy (EDX). SEM and DSC-based thermoporometry analyses demonstrated the formation of nanoporous structures after IL removal from CER networks, thus showing the effective role of IL as a porogen. Pore sizes varied from 20 to 180 nm with an average pore diameter of around 45-60 nm depending on the initial IL content. The thermal stability of nanoporous CER-based films was investigated by thermogravimetric analysis.

  12. Synthesis of diisooctyl adipate catalyzed by lipase-displaying Pichia pastoris whole-cell biocatalysts%酵母表面展示脂肪酶合成己二酸二异辛酯

    Institute of Scientific and Technical Information of China (English)

    张娜; 金子; 林影; 郑穗平; 韩双艳

    2013-01-01

    An enzyme-displaying yeast as a whole-cell biocatalyst is an alternative to immobihzed enzyme,due to its low-cost preparation and simple recycle course.Here,lipase-displaying Pichia pastoris whole-cell was used as a biocatalyst to synthesize diisooctyl adipate in the non-aqueous system.The maximum productivity of diisooctyl adipate was obtained as 85.0% in a 10 mL reaction system.The yield could be reached as high as 97.8% when the reaction system was scaled up to 200 mL.The purity obtained is 98.2% after vacuum distillation.Thus,the lipase-displaying P.pastoris whole-cell biocatalyst was promising in commercial application for diisooctyl adipate synthesis in non-aqueous phase.%展示酶的酵母细胞既具有固定化酶的优点,又有制备简单、成本较低的特点.采用表面展示南极假丝酵母脂肪酶B (Candida antarctica lipase B,CALB)的毕赤酵母细胞催化合成己二酸二异辛酯(Diisooctyl adipate,DIOA),对该反应体系进行优化,并实现了初步工艺放大制备.经条件优化后,在10mL反应体系中,DIOA的产率可达85.0%.该工艺放大到200mL反应体系时,DIOA产率可达97.8%.经减压蒸馏,DIOA纯度可达到98.2%.该酵母表面展示脂肪酶在合成绿色润滑油己二酸二异辛酯中具有良好应用前景.

  13. 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

    OpenAIRE

    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...

  14. 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

    DEFF Research Database (Denmark)

    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....... 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....

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

    OpenAIRE

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

    2010-01-01

    Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LC–TOFMS method were compared with the DGF method. The DGF method consistent...

  16. Triterpene hexahydroxydiphenoyl esters and a quinic acid purpurogallin carbonyl ester from the leaves of Castanopsis fissa.

    Science.gov (United States)

    Huang, Yong-Lin; Tsujita, Takaaki; Tanaka, Takashi; Matsuo, Yosuke; Kouno, Isao; Li, Dian-Peng; Nonaka, Gen-ichiro

    2011-11-01

    Triterpene hexahydroxydiphenoyl (HHDP) esters have only been isolated from Castanopsis species, and the distribution of these esters in nature is of chemotaxonomical interest. In this study, the chemical constituents of the leaves of Castanopsis fissa were examined in detail to identify and isolate potential HHDP esters. Together with 53 known compounds, 3,4-di-O-galloyl-1-O-purpurogallin carbonyl quinic acid (1) and 3,24-(S)-HHDP-2α,3β,23,24-tetrahydroxytaraxastan-28,20β-olide (2) were isolated and their structures were elucidated by spectroscopic and chemical methods. The polyphenols of the leaves were mainly composed of galloyl quinic acids, triterpenes HHDP esters, ellagitannins and flavonol glycosides. In particular, the isolation yields of 1,3,4-trigalloyl quinic acid and compound 2 were 1.53% and 0.27%, respectively, from the fresh leaves. The presence of lipid soluble HHDP esters of oleanane-type triterpenes as one of the major metabolites is an important chemotaxonomical discovery. Lipase inhibition activities and ORAC values of the major constituents were compared. The triterpene HHDP ester showed moderate lipase inhibition activity and myricitrin gave the largest ORAC value.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Curing mechanism of alkaline phenolic resin with organic ester

    Institute of Scientific and Technical Information of China (English)

    Huang Renhe; Wang Yanmin; Zhang Baoping

    2014-01-01

    To study the curing mechanism of alkaline phenolic resin with organic ester, three esters were chosen to react with three systems - alkaline phenolic resin, potassium hydroxide aqueous solution containing phenol, and potassium hydroxide aqueous solution. The variations of pH, heat release and gel pH during the reactions were monitored and measured. Infrared spectroscopy (IR) and thermal gravity analysis (TG) techniques were used to characterize the curing reaction. It was found that organic ester is only partial y hydrolyzed and resin can be cured through organic ester hydrolysis process as wel as the reaction with redundant organic ester. The sequential curing mechanism of alkaline phenolic resin cured by organic ester was identified as fol ows: a portion of organic ester is firstly hydrolyzed owing to the effect of the strong alkaline; the gel is then formed after the pH decreases to about 10.8-10.88, meanwhile, the redundant organic ester (i.e. non-hydrolysis ester) starts the curing reaction with the resin. It has also been found that the curing rate depends on the hydrolysis velocity of organic ester. The faster the hydrolysis speed of the ester, the faster the curing rate of the resin.

  19. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti

    2011-09-01

    Full Text Available Abstract Background Wax esters are industrially relevant molecules exploited in several applications of oleochemistry and food industry. At the moment, the production processes mostly rely on chemical synthesis from rather expensive starting materials, and therefore solutions are sought from biotechnology. Bacterial wax esters are attractive alternatives, and especially the wax ester metabolism of Acinetobacter sp. has been extensively studied. However, the lack of suitable tools for rapid and simple monitoring of wax ester metabolism in vivo has partly restricted the screening and analyses of potential hosts and optimal conditions. Results Based on sensitive and specific detection of intracellular long-chain aldehydes, specific intermediates of wax ester synthesis, bacterial luciferase (LuxAB was exploited in studying the wax ester metabolism in Acinetobacter baylyi ADP1. Luminescence was detected in the cultivation of the strain producing wax esters, and the changes in signal levels could be linked to corresponding cell growth and wax ester synthesis phases. Conclusions The monitoring system showed correlation between wax ester synthesis pattern and luminescent signal. The system shows potential for real-time screening purposes and studies on bacterial wax esters, revealing new aspects to dynamics and role of wax ester metabolism in bacteria.

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

    Science.gov (United States)

    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.

  1. Volatile profiles of members of the USDA Geneva Malus Core Collection: utility in evaluation of a hypothesized biosynthetic pathway for esters derived from 2-methylbutanoate and 2-methylbutan-1-ol.

    Science.gov (United States)

    Sugimoto, Nobuko; Forsline, Philip; Beaudry, Randolph

    2015-02-25

    The volatile ester and alcohol profiles of ripening apple fruit from 184 germplasm lines in the USDA Malus Germplasm Repository at the New York Agricultural Experiment Station in Geneva, NY, USA, were evaluated. Cluster analysis suggested biochemical relationships exist between several ester classes. A strong linkage was revealed between 2-methylbutanoate, propanoate, and butanoate esters, suggesting the influence of the recently proposed "citramalic acid pathway" in apple fruit. Those lines with a high content of esters formed from 2-methylbutan-1-ol and 2-methylbutanoate (2MB) relative to straight-chain (SC) esters (high 2MB/SC ratio) exhibited a marked increase in isoleucine and citramalic acid during ripening, but those lines with a low content did not. Thus, the data were consistent with the existence of the hypothesized citramalic acid pathway and suggest that the Geneva Malus Germplasm Repository, appropriately used, could be helpful in expanding our understanding of mechanisms for fruit volatile synthesis and other aspects of secondary metabolism.

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

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

  4. Atmospheric oxidation of selected alcohols and esters

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  5. Reduction of Aromatic α-Keto Esters by Commercially Available Zinc Dust and Ammonium Formate:Formation of Aromatic a-Hydroxy Esters

    Institute of Scientific and Technical Information of China (English)

    CHEN Gang; YAO Guo-xin; SONG Guang-wei; ZHU Jin-tao

    2011-01-01

    Various aromatic α-keto esters were rapidly and selectively reduced to aromatic α-hydroxy esters by commercially available zinc dust and ammonium formate in the presence of other functional groups such as halogens,methoxy and esters.

  6. Withanolides and Sucrose Esters from Physalis neomexicana.

    Science.gov (United States)

    Cao, Cong-Mei; Wu, Xiaoqing; Kindscher, Kelly; Xu, Liang; Timmermann, Barbara N

    2015-10-23

    Four withanolides (1-4) and two sucrose esters (5, 6) were isolated from the aerial parts of Physalis neomexicana. The structures of 1-6 were elucidated through a variety of spectroscopic techniques. Cytotoxicity studies of the isolates revealed that 2 inhibited human breast cancer cell lines (MDA-MB-231 and MCF-7) with IC50 values of 1.7 and 6.3 μM, respectively.

  7. Determination of phthalate esters in human semen.

    Science.gov (United States)

    Waliszewski, M; Szymczyński, G A

    1990-01-01

    Phthalate esters are a large group of chemical compounds used in the production of plastics, household articles, packages, cosmetics and plant pesticides. World production of phthalates is estimated to be several million tons a year. Recent observations indicate some mutagenic, cancerogenic and orchidotoxic effect of these compounds. Therefore, to assess the extent of risk it is imperative to have an adequate analytical method. The following is simple and relatively inexpensive. The study group consisted of 58 men.

  8. Antibacterial sesquiterpene aryl esters from Armillaria mellea.

    Science.gov (United States)

    Donnelly, D M; Abe, F; Coveney, D; Fukuda, N; O'Reilly, J; Polonsky, J; Prangé, T

    1985-01-01

    Investigation of the mycelial extract of Armillaria mellea led to the isolation of the known melleolide (2a) and two new sesquiterpene aryl eters, 4-O-methylmelleolide (2b) and judeol (1c). Their structures were deduced from spectral data and that of (2b) confirmed by X-ray analysis. The new esters (1c) and (2b) showed strong antibacterial activity against gram-positive bacteria.

  9. Ethyl ester production from (RBD palm oil

    Directory of Open Access Journals (Sweden)

    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.

  10. Methyl and ethyl soybean esters production

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Anna Leticia Montenegro Turtelli; Park, Kil Jin; Zorzeto, Thais Queiroz [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: annalets@feagri.unicamp.br; Bevilaqua, Gabriela [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

    2008-07-01

    Biodiesel is a fuel obtained from triglycerides found in nature, like vegetable oils and animal fats. Nowadays it has been the subject of many researches impulses by the creation of the Brazilian law that determined the blend of 2% of biodiesel with petrodiesel. Basically, there are no limitations on the oilseed type for chemical reaction, but due to high cost of this major feedstock, it is important to use the grain that is available in the region of production. Soybean is the oilseed mostly produced in Brazil and its oil is the only one that is available in enough quantity to supply the current biodiesel demand. The objective of this work was to study the effects of reaction time and temperature on soybean oil transesterification reaction with ethanol and methanol. A central composite experimental design with five variation levels was used and response surface methodology applied for the data analysis. The statistical analysis of the results showed that none of the factors affected the ethyl esters production. However, the methyl esters production suffered the influence of temperature (linear effect), reaction time (linear and quadratic) and interaction of these two variables. None of the generated models showed significant regression consequently it was not possible to build the response surface. The experiments demonstrated that methanol is the best alcohol for transesterification reactions and the ester yield was up to 85%. (author)

  11. Structure-barrier property relationship of biodegradable poly(butylene succinate) and poly[(butylene succinate)-co-(butylene adipate)] nanocomposites: influence of the rigid amorphous fraction.

    Science.gov (United States)

    Charlon, S; Marais, S; Dargent, E; Soulestin, J; Sclavons, M; Follain, N

    2015-11-28

    Composites composed of polyesters, poly(butylene succinate) (PBS) or poly[(butylene succinate)-co-(butylene adipate)] (PBSA), and 5 wt% of montmorillonite (CNa) or organo-modified montmorillonite (C30B) were melt-processed and transformed into films by either compression-molding or extrusion-calendering. XRD, rheological measurements and TEM images clearly indicated that films containing CNa are microcomposites, while nanocomposites were observed for those containing C30B. Using Flash DSC, it was possible, for the first time, not only to measure the heat capacity step at the glass transition of these two materials in their amorphous state, but also to investigate whether the preparation technique influenced the Rigid Amorphous Fraction (RAF) in our PBS- and PBSA-based nanocomposites. In this work, we have successfully shown the correlation between the microstructure of the films and their barrier properties, and especially the role played by the RAF. Indeed, the lowest permeabilities to gases and to water were determined in the films containing the highest RAF in both PBS- and PBSA-based materials.

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

    Science.gov (United States)

    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.

  13. Scientific Opinion on the safety assessment of the substance adipic acid dihydrazide, CAS No 1071-93-8, for use in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2015-01-01

    Full Text Available This scientific opinion of EFSA’s Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF deals with the risk assessment of the additive adipic acid dihydrazide, CAS No 1071-93-8, FCM substance No 987 for use as a crosslinker for acrylic polymer with keto side groups coated on polyolefins and adhesives in laminates made from plastics. The coating is not for direct food contact but used in inner layers of plastics laminates which are intended to be used for all types of foodstuffs at all time-temperature conditions applicable according to the laminate’s properties. Specific migration of the substance was measured from a coated low-density polyethylene (LDPE film, the substance was not detectable (limit of detection (LOD 0.019 mg/kg with the food simulants 3 % acetic acid, 10 % ethanol for 10 days at 40 °C and isooctane for 2 days at 20 °C. According the in vitro and in vivo studies available the substance is not considered genotoxic. Based on an in vivo micronucleus test, the substance is not considered to be clastogenic/aneugenic under the tested conditions. The CEF Panel concluded that there is no safety concern for the consumer if the substance is used as a crosslinker for non-self-supporting coatings on polyolefins and adhesives for laminates not in direct contact with food and its migration does not exceed 0.050 mg/kg food.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

    Science.gov (United States)

    Eleutério Dos Santos, Caroline Mongruel; Pietrowski, Giovana de Arruda Moura; Braga, Cíntia Maia; Rossi, Márcio José; Ninow, Jorge; Machado Dos Santos, Tâmisa Pires; Wosiacki, Gilvan; Jorge, Regina Maria Matos; Nogueira, Alessandro

    2015-06-01

    The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation. © 2015 Institute of Food Technologists®

  17. Linear and branched poly(omega-hydroxyacid) esters in plant cutins.

    Science.gov (United States)

    Graça, José; Lamosa, Pedro

    2010-09-08

    Poly(omega-hydroxyacid) ester oligomers were obtained from the cutin of four plant cuticles by partial depolymerization methanolysis. The structure of these oligomers was determined by electrospray ionization coupled to tandem mass spectrometry (ESI-MS/MS) analysis of their lithium-adducts, showing which monomers were present and their relative position. Dimers up to heptamers were identified, in a total yield of oligomers of up to 50% of the total cutin content. Two main structural types of poly(omega-hydroxyacid) ester oligomers were found. Poly(10,16-dihydroxyhexadecanoic acid) esters were the main oligomers in the cutin of Lycopersicum esculentum fruit, with a predominantly branched structure. The 1D and 2D NMR analysis of these oligomers showed that inter-monomer linkages were mostly in secondary midchain hydroxyls, in a ratio of 4.5 to 1, compared with esterification in the primary omega-hydroxyls. In Hedera helix leaves cutin, poly(9-epoxy-18-hydroxyoctadecanoic acid) esters were the dominant oligomers, composed of monomers linearly linked head-to-tail. It is proposed that the cutin polyesters have different poly(omega-hydroxyacid)ester domains, either built of linear chains, where the C18-epoxy omega-hydroxyacids are dominant, or forming a highly branched network, where the C16-dihydroxy omega-hydroxyacids predominate. It is hypothesized that the C18 linear polyester can account for the ordered lamellae seen at ultrastructural level in H. helix cuticle, and that the C16 mostly branched polyester will be the basis of the reticulate structure seen in L. esculentum cuticle.

  18. SYNTHESIS AND CHARACTERIZATION OF THERMOTROPIC COPOLYESTERS AND COPOLY (ESTER-AMIDE)S CONTAINING OXYETHYLENE-ETHER AS THE SPACER

    Institute of Scientific and Technical Information of China (English)

    WANG Shanger; MO Zhishen; ZHANG Hongfang; FENG Zhiliu

    1995-01-01

    Flexible oxyethylene-ether was introduced into the aromatic copolyesters and copoly (ester-amide)s to reduce the melting point of resulting polymers. The melting point was greatly reduced to 200℃ or even lower in some cases, and the molecular weight was satisfactorily high as reflected by inherent viscosity. The polymers exhibited high thermal stability and good mechanical properties as determined by TGA and mechanical tests. The copolyester showed better crystallinity and liquid crystallinity than corresponding copoly(ester-amide)s with similar monomer composition as reflected by POM observation and WAXD study. The melting points for both copolyesters and copoly (ester-amide)s showed great dependence on the pacetoxybenzoic acid (PAB) content in monomer composition and reached the lowest value when PAB was 29 mol%.

  19. Identification of 3-MCPD esters to verify the adulteration of extra virgin olive oil.

    Science.gov (United States)

    Hung, Wei-Ching; Peng, Guan-Jhih; Tsai, Wen-Ju; Chang, Mei-Hua; Liao, Chia-Ding; Tseng, Su-Hsiang; Kao, Ya-Min; Wang, Der-Yuan; Cheng, Hwei-Fang

    2017-09-01

    The adulteration of olive oil is an important issue around the world. This paper reports an indirect method by which to identify 3-monochloropropane-1,2-diol (3-MCPD) esters in olive oils. Following sample preparation, the samples were spiked with 1,2-bis-palmitoyl-3-chloropropanediol standard for analysis using gas chromatograph-tandem mass spectrometry. The total recovery ranged from 102.8% to 105.5%, the coefficient of variation ranged from 1.1% to 10.1%, and the limit of quantification was 0.125 mg/kg. The content of 3-MCPD esters in samples of refined olive oil (0.97-20.53 mg/kg) exceeded those of extra virgin olive oil (non-detected to 0.24 mg/kg). These results indicate that the oil refining process increased the content of 3-MCPD esters, which means that they could be used as a target compound for the differentiation of extra virgin olive oil from refined olive oil in order to prevent adulteration.

  20. List of Article Contents

    Directory of Open Access Journals (Sweden)

    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    

  1. Environmentally friendly properties of vegetable oil methyl esters

    Directory of Open Access Journals (Sweden)

    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.

  2. Measurement uncertainty of ester number, acid number and patchouli alcohol of patchouli oil produced in Yogyakarta

    Science.gov (United States)

    Istiningrum, Reni Banowati; Saepuloh, Azis; Jannah, Wirdatul; Aji, Didit Waskito

    2017-03-01

    Yogyakarta is one of patchouli oil distillation center in Indonesia. The quality of patchouli oil greatly affect its market price. Therefore, testing quality of patchouli oil parameters is an important concern, one through determination of the measurement uncertainty. This study will determine the measurement uncertainty of ester number, acid number and content of patchouli alcohol through a bottom up approach. Source contributor to measurement uncertainty of ester number is a mass of the sample, a blank and sample titration volume, the molar mass of KOH, HCl normality, and replication. While the source contributor of the measurement uncertainty of acid number is the mass of the sample, the sample titration volume, the relative mass and normality of KOH, and repetition. Determination of patchouli alcohol by Gas Chromatography considers the sources of measurement uncertainty only from repeatability because reference materials are not available.

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

    DEFF Research Database (Denmark)

    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. 16.5 mmol...

  4. Evaluation of alkyl esters from Camelina sativa oil as biodiesel and as blend components in ultra low-sulfur diesel fuel.

    Science.gov (United States)

    Moser, Bryan R; Vaughn, Steven F

    2010-01-01

    Methyl and ethyl esters were prepared from camelina [Camelina sativa (L.) Crantz] oil by homogenous base-catalyzed transesterification for evaluation as biodiesel fuels. Camelina oil contained high percentages of linolenic (32.6 wt.%), linoleic (19.6 wt.%), and oleic (18.6 wt.%) acids. Consequently, camelina oil methyl and ethyl esters (CSME and CSEE) exhibited poor oxidative stabilities and high iodine values versus methyl esters prepared from canola, palm, and soybean oils (CME, PME, and SME). Other fuel properties of CSME and CSEE were similar to CME, PME, and SME, such as low temperature operability, acid value, cetane number, kinematic viscosity, lubricity, sulfur and phosphorous contents, as well as surface tension. As blend components in ultra low-sulfur diesel fuel, CSME and CSEE were essentially indistinguishable from SME and soybean oil ethyl ester blends with regard to low temperature operability, kinematic viscosity, lubricity, and surface tension.

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

    Science.gov (United States)

    Olutoye, M A; Hameed, B H

    2011-06-01

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

  6. Acyl-lupeol esters from Parahancornia amapa (Apocynaceae)

    OpenAIRE

    Carvalho,Mário G. de; Velloso,Carlos R. X.; Braz-Filho,Raimundo; Costa,William F. da

    2001-01-01

    From the roots of Parahancornia amapa, family Apocynaceae, the following compounds were isolated and identified nine new and ten known 3beta-O-acyl lupeol esters, beta-sitosterol, stigmasterol, beta-sitosterone, the triterpenoids beta-amyrin, alpha-amyrin, lupeol and their acetyl derivatives. The structures of these compounds were established by spectroscopic data, mainly ¹H and 13C (HBBD and DEPT) NMR spectra. The methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of ...

  7. Isolation and identification of an ester from a crude oil

    Science.gov (United States)

    Phillips, H.F.; Breger, I.A.

    1958-01-01

    A dioctylphthalate has been isolated from a crude oil by means of adsorption column chromatography. The ester was identified by means of elemental analysis, refractive index, and its infra-red absorption spectrum. Saponification of the isolate and examination of the resultant alcohol by means of infrared absorption spectra led to the conclusion that the ester is a branched chain dioctylphthalate. This is the first reported occurrence of an ester in crude petroleum. ?? 1958.

  8. Wax Ester Fermentation and Its Application for Biofuel Production.

    Science.gov (United States)

    Inui, Hiroshi; Ishikawa, Takahiro; Tamoi, Masahiro

    2017-01-01

    In Euglena cells under anaerobic conditions, paramylon, the storage polysaccharide, is promptly degraded and converted to wax esters. The wax esters synthesized are composed of saturated fatty acids and alcohols with chain lengths of 10-18, and the major constituents are myristic acid and myristyl alcohol. Since the anaerobic cells gain ATP through the conversion of paramylon to wax esters, the phenomenon is named "wax ester fermentation". The wax ester fermentation is quite unique in that the end products, i.e. wax esters, have relatively high molecular weights, are insoluble in water, and accumulate in the cells, in contrast to the common fermentation end products such as lactic acid and ethanol.A unique metabolic pathway involved in the wax ester fermentation is the mitochondrial fatty acid synthetic system. In this system, fatty acid are synthesized by the reversal of β-oxidation with an exception that trans-2-enoyl-CoA reductase functions instead of acyl-CoA dehydrogenase. Therefore, acetyl-CoA is directly used as a C2 donor in this fatty acid synthesis, and the conversion of acetyl-CoA to malonyl-CoA, which requires ATP, is not necessary. Consequently, the mitochondrial fatty acid synthetic system makes possible the net gain of ATP through the synthesis of wax esters from paramylon. In addition, acetyl-CoA is provided in the anaerobic cells from pyruvate by the action of a unique enzyme, oxygen sensitive pyruvate:NADP(+) oxidoreductase, instead of the common pyruvate dehydrogenase multienzyme complex.Wax esters produced by anaerobic Euglena are promising biofuels because myristic acid (C14:0) in contrast to other algal produced fatty acids, such as palmitic acid (C16:0) and stearic acid (C18:0), has a low freezing point making it suitable as a drop-in jet fuel. To improve wax ester production, the molecular mechanisms by which wax ester fermentation is regulated in response to aerobic and anaerobic conditions have been gradually elucidated by identifying

  9. Baker's yeast: production of D- and L-3-hydroxy esters

    DEFF Research Database (Denmark)

    Dahl, Allan Carsten; Madsen, Jørgen Øgaard

    1998-01-01

    Baker's yeast grown under oxygen limited conditions and used in the reduction of 3-oxo esters results in a shift of the stereoselectivity of the yeast towards D-hydroxy esters as compared with ordinary baker's yeast. The highest degree of stereoselectivity was obtained with growing yeast or yeast...... harvested while growing. In contrast, the stereoselectivity was shifted towards L-hydroxy esters when the oxo esters were added slowly to ordinary baker's yeast supplied with gluconolactone as co-substrate. The reduction rate with gluconolactone was increased by active aeration. Ethyl L-(S)-3...

  10. Chemical and physical analyses of wax ester properties

    Directory of Open Access Journals (Sweden)

    Sejal Patel

    2001-05-01

    Full Text Available Wax esters are major constituents of the surface lipids in many terrestrial arthropods, but their study is complicated by their diversity. We developed a procedure for quantifying isomers in mixtures of straight-chain saturated and unsaturated wax esters having the same molecular weights, using single-ion monitoring of the total ion current data from gas chromatography-mass spectrometry. We examined the biological consequences of structural differences by measuring the melting temperatures, Tm, of >60 synthetic wax esters, containing 26-48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38-73°C. The main factor affecting Tm was the total chain length of the wax ester, but the placement of the ester bond also affected Tm. Insertion of a double bond into either the alcohol or acid moiety decreased Tm by ~30°C. Simple mixtures of wax esters with n-alkanes melted several °C lower than predicted from the melting points of the component lipids. Our results indicate that the wax esters of primary alcohols that are most typically found on the cuticle of terrestrial arthropods occur in a solid state under physiological conditions, thereby conferring greater waterproofing. Wax esters of secondary alcohols, which occur on melanopline grasshoppers, melted >60°C below primary esters of the same molecular weight and reduced Tm of the total surface lipids to environmental values.

  11. Pengaruh Rasio Mol Reaktan dan Lama Sulfonasi terhadap Karakteristik Methyl Ester Sulfonic (MES) dari Metil Ester Minyak Sawit (Effects of Mol Ratio and Sulfonation Time on Methyl Ester Sulfonic (MES) Characteristics from Methyl Ester of Palm Oil)

    OpenAIRE

    Sri Hidayati; Pudji Permadi; Hestuti Eni

    2017-01-01

    An experiment of sulfonation process of methyl ester to produce methyl ester sulfonates (MES) was caried out using methyl ester palm oil in factorial design and NaHSO as sulfonating agent with variation of ratio mol NaHSO : methyl ester (1:1.25, 1:1.5, 1:1.75 and 1:2 ) and sulfonation time (3 hour (L1), 4.5 hour (L2) and 6 hour (L3). The result showed that the best sulfonation condition present in 1:1,5 mol ratio and sulfonation time of 4,5 hour. The best characteristic of MES was produced em...

  12. A novel thermooxidatively stable poly(ester-imide-benzoxazole)

    Energy Technology Data Exchange (ETDEWEB)

    Sundar, R.A.; Mathias, L.J. [Univ. of Sothern Mississippi, Hattiesburg, MS (United States)

    1993-12-31

    A poly(ester-amide-imide) was synthesized by the low temperature solution polycondensation of 4-amino-5-hydroxy-N,4{prime}-hydroxyphenyl phthalimide with isophthaloyl chloride. Subsequent thermal cyclodehydration of the poly(ester-amide-imide) at 320{degrees}C in vacuum afforded the poly(ester-imide-benzoxazole). This polymer was only soluble in sulfuric acid. FTIR and NMR spectra confirmed structure. The poly(ester-imide-benzoxazole) had no detectable thermal transitions up to 500{degrees}C in nitrogen, and was reasonably stable in air and nitrogen, with weight retentions of 95% at 500{degrees}C.

  13. Estereótipos e mulheres na cultura marroquina

    OpenAIRE

    Sadiqi,Fatima

    2008-01-01

    Estereótipos sobre as mulheres no Marrocos podem ser caracterizados como crenças culturais incompletas e inexatas mantidas por algumas pessoas e que se encontram inscritos em expressões lingüísticas ou em discursos subliminares. A cultura popular marroquina emprega representações poderosas para transmitir e sustentar tais estereótipos. Embora existam alguns estereótipos positivos, a maioria dos estereótipos sobre as mulheres no Marrocos é negativa e reflete ditames patriarcais subliminares qu...

  14. Papain-specific activating esters in aqueous dipeptide synthesis.

    Science.gov (United States)

    de Beer, Roseri J A C; Zarzycka, Barbara; Mariman, Michiel; Amatdjais-Groenen, Helene I V; Mulders, Marc J; Quaedflieg, Peter J L M; van Delft, Floris L; Nabuurs, Sander B; Rutjes, Floris P J T

    2012-06-18

    Enzymatic peptide synthesis has the potential to be a viable alternative for chemical peptide synthesis. Because of the increasing commercial interest in peptides, new and improved enzymatic synthesis methods are desirable. In recently developed enzymatic strategies such as substrate mimetic approaches and enzyme-specific activation, use of the guanidinophenyl ester (OGp) group has been shown to suffer from some drawbacks. OGp esters are sensitive to spontaneous chemical hydrolysis and the group is expensive to synthesize and therefore not suitable for large-scale applications. On the basis of earlier computational studies, we hypothesized that OGp might be replaceable by simpler ester groups to make the enzyme-specific activation approach to peptide bond formation more accessible. To this end, a set of potential activating esters (Z-Gly-Act) was designed, synthesized, and evaluated. Both the benzyl (OBn) and the dimethylaminophenyl (ODmap) esters gave promising results. For these esters, the scope of a model dipeptide synthesis reaction under aqueous conditions was investigated by varying the amino acid donor. The results were compared with those obtained from a previous study of Z-X(AA) -OGp esters. Computational docking analysis of the set of esters was performed in order to provide insight into the differences in the reactivities of all the potential activating esters. Finally, selected ODmap- and OBn-activated amino acids were applied in the synthesis of two biologically active dipeptides on preparative scales. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Bioactive caffeic acid esters from Glycyrrhiza glabra.

    Science.gov (United States)

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

    2009-01-01

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

  16. Tandem transformation of glycerol to esters.

    Science.gov (United States)

    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.

  17. Transferable force field for carboxylate esters: application to fatty acid methylic ester phase equilibria prediction.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Boutin, Anne

    2012-03-15

    In this work, a new transferable united-atoms force field for carboxylate esters is proposed. All Lennard-Jones parameters are reused from previous parametrizations of the AUA4 force field, and only a unique set of partial electrostatic charges is introduced for the ester chemical function. Various short alkyl-chain esters (methyl acetate, ethyl acetate, methyl propionate, ethyl propionate) and two fatty acid methylic esters (methyl oleate and methyl palmitate) are studied. Using this new force field in Monte Carlo simulations, we show that various pure compound properties are accurately predicted: saturated liquid densities, vapor pressures, vaporization enthalpies, critical properties, liquid-vapor surface tensions. Furthermore, a good accuracy is also obtained in the prediction of binary mixture pressure-composition diagrams, without introducing empirical binary interaction parameters. This highlights the transferability of the proposed force field and gives the opportunity to simulate mixtures of industrial interest: a demonstration is performed through the simulation of the methyl oleate + methanol mixture involved in the purification sections of biodiesel production processes.

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

    DEFF Research Database (Denmark)

    Karilainen, Topi; Vuorela, Timo; Vattulainen, Ilpo

    2015-01-01

    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 ...

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

    NARCIS (Netherlands)

    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 hal

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

    Science.gov (United States)

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

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

    OpenAIRE

    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...

  2. 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

    Directory of Open Access Journals (Sweden)

    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.

  3. Catalytic oxidation of cyclohexanone to adipic acid catalysed by supported phosphotungstic acid%固载磷钨酸催化氧化环己酮合成己二酸

    Institute of Scientific and Technical Information of China (English)

    叶天旭; 马雪妮; 刘京燕

    2009-01-01

    Adipic acid was synthesized via oxidation of cyclohexanone using phosphotungstic acid (H3PW12O40)/Al2O3 as the catalyst and 30% H2O2 as the oxidant. The influence of reaction condition on the yield of adipic acid was investigated. The optimum reaction condition was obtained as follows: n (hydrogen peroxide): n (phosphoric acid ): n (cyclohexanone)=4.4:0.99:1 ,n( phosphotungstic acid):n(cyclohexanone) =1:290, reaction at 75℃ for 1 h and then at 93℃ for7 h. Adipic acid yield of 95.5% was attained using with phosphoric acid as the promoter. Strength of the supported catalyst was enhanced by introduction of lanthanum.%以氧化铝固载的磷钨酸为催化剂,30%过氧化氢为氧化剂,催化氧化环己酮合成己二酸.考察反应条件对己二酸收率的影响,得到最佳工艺条件:n(过氧化氢)∶n(磷酸)∶n(环己酮)=4.4∶0.99∶1,n(磷钨酸)∶n(环己酮)=1∶290,75℃反应1 h,再于93℃反应7 h,加入磷酸助剂,己二酸收率达95.5%.采用镧改性氧化铝固载磷钨酸,固载强度高.

  4. Osteoconductive bio-based meshes based on Poly(hydroxybutyrate-co-hydroxyvalerate) and poly(butylene adipate-co-terephthalate) blends

    Energy Technology Data Exchange (ETDEWEB)

    Nar, Mangesh; Staufenberg, Gerrit; Yang, Bing [Department of Material Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017 (United States); Robertson, Lesli [Department of Fibers, College of Visual Arts and Design, 1155 Union Circle #305100, Denton, TX 76203-5017 (United States); Patel, Rinkesh H. [Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A and M University Baylor College of Dentistry, Dallas, TX 75246 (United States); Varanasi, Venu G., E-mail: vvaranasi@bcd.tamhsc.edu [Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A and M University Baylor College of Dentistry, Dallas, TX 75246 (United States); D' Souza, Nandika Anne, E-mail: nandika.dsouza@unt.edu [Department of Material Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017 (United States); Department of Mechanical and Energy Engineering, University of North Texas, 1155 Union Circle # 311098, Denton, TX 76203-5017 (United States)

    2014-05-01

    Poly(butylene adipate-co-terephthalate) (PBAT) and Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) are biopolymers that have the potential to be used in applications of bone healing. In this study, it is hypothesized that the polymer blend has the combined strength and osteoconductivity to support osteoblast collagen formation. PBAT (PBAT 100), and a blend with 20% PHBV (PBAT 80) were extruded in the form of fibers and then knitted in the form of mesh. These were tested in the warp as well as weft direction for the tensile properties; these showed that the weft direction had higher performance than the warp. The individual fibers were kept in phosphate buffered saline (PBS) over the period of 8 weeks and were tested for the storage and loss modulus using a dynamic mechanical analyser (DMA). The results indicated that mechanical relaxation strength showed a decrease and then an increase. In vitro osteoconductivity studies were done by using differentiating osteoblasts (MC3T3-E1 subclone 4 cells). Environmental Scanning Electron Microscopy (ESEM) showed that pre-soaking the samples in α-MEM for two weeks resulted in cell attachment and growth. X-ray diffraction (XRD) was used to determine the change in structure of polymers due to in vitro degradation for two weeks. Raman spectroscopy showed that all scaffolds supported the formation of a collagenous network over the scaffold surfaces. For a combination of knittable manufacturing, mechanical performance and osteoconductivity, blends offer an effective route. - Highlights: • PBAT and PHBV blend can be knitted to form mesh with good mechanical properties. • PBAT and PHBV blend do not show significant weight loss over a period of 8 weeks in PBS. • Osteoblast cell culture was done on these samples. • They support extracellular matrix and growth and hence are osteoconductive.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  7. Preparation of esters of gallic acid with higher primary alcohols

    NARCIS (Netherlands)

    Kerk, G.J.M. van der; Verbeek, J.H.; Cleton, J.C.F.

    1951-01-01

    The esters of gallic acid and higher primary alcohols, especially fatty alcohols, have recently gained considerable interest as possible antioxidants for fats. Two independent methods for the preparation of these esters are described. In the first method the hitherto unknown compound galloyl chlorid

  8. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted phosphate ester (generic... Substances § 721.3080 Substituted phosphate ester (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted phosphate...

  9. Engineering modular ester fermentative pathways in Escherichia coli.

    Science.gov (United States)

    Layton, Donovan S; Trinh, Cong T

    2014-11-01

    Sensation profiles are observed all around us and are made up of many different molecules, such as esters. These profiles can be mimicked in everyday items for their uses in foods, beverages, cosmetics, perfumes, solvents, and biofuels. Here, we developed a systematic 'natural' way to derive these products via fermentative biosynthesis. Each ester fermentative pathway was designed as an exchangeable ester production module for generating two precursors- alcohols and acyl-CoAs that were condensed by an alcohol acyltransferase to produce a combinatorial library of unique esters. As a proof-of-principle, we coupled these ester modules with an engineered, modular, Escherichia coli chassis in a plug-and-play fashion to create microbial cell factories for enhanced anaerobic production of a butyrate ester library. We demonstrated tight coupling between the modular chassis and ester modules for enhanced product biosynthesis, an engineered phenotype useful for directed metabolic pathway evolution. Compared to the wildtype, the engineered cell factories yielded up to 48 fold increase in butyrate ester production from glucose.

  10. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Science.gov (United States)

    2010-07-01

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

  11. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Science.gov (United States)

    2010-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Phenylpropanoid acid esters from Korean propolis and their antioxidant activities.

    Science.gov (United States)

    Lee, In-Kyoung; Han, Myung-Suk; Kim, Dae-Won; Yun, Bong-Sik

    2014-08-01

    Ten phenylpropanoic acid esters were isolated from an ethanolic extract of Korean propolis. Their structures were elucidated by spectroscopic methods including NMR and ESI-MS. Caffeic acid esters with catechol moiety exhibited significant ABTS and DPPH radical scavenging activity and protective effect against DNA damage by a Fenton reaction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Phthalic acid esters found in municipal organic waste

    DEFF Research Database (Denmark)

    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...... matter with high biogas yields and efficient reduction of the phthalic acid ester contamination....

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

    Science.gov (United States)

    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…

  16. Production of both esters and biogas from Mexican poppy

    African Journals Online (AJOL)

    AJL

    Methyl esters of fatty acids are produced by the transesterification of triglycerides of vegetable oils with methanol with the help of a catalyst. (Klass, 1998). ... sodium sulphate (20 g) and was evaporated at 40°C to get purified oil. For making it more ... producing mixture of fatty acid alkyls ester and glycerol. Proximate analysis ...

  17. 13-week oral toxicity study with stanol esters in rats

    NARCIS (Netherlands)

    Turnbull, D.; Whittaker, M.H.; Frankos, V.H.; Jonker, D.

    1999-01-01

    Plant sterols and their saturated derivatives, known as stanols, reduce serum cholesterol when consumed in amounts of approximately 2 g per day. Stanol fatty acid esters have been developed as a highly fat-soluble form that may lower cholesterol more effectively than stanols. Stanol esters occur nat

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

    OpenAIRE

    HASSAN TAJIK; KHALIL TABATABAEIAN; MAHMOOD SHAHBAZI

    2006-01-01

    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.

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

    Science.gov (United States)

    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…

  20. Synthesis and biological evaluation of new creatine fatty esters revealed dodecyl creatine ester as a promising drug candidate for the treatment of the creatine transporter deficiency.

    Science.gov (United States)

    Trotier-Faurion, Alexandra; Dézard, Sophie; Taran, Frédéric; Valayannopoulos, Vassili; de Lonlay, Pascale; Mabondzo, Aloïse

    2013-06-27

    The creatine transporter deficiency is a neurological disease caused by impairment of the creatine transporter SLC6A8, resulting in mental retardation associated with a complete absence of creatine within the brain and cellular energy perturbation of neuronal cells. One of the therapeutic hypotheses was to administer lipophilic creatine derivatives which are (1) thought to have better permeability through the cell membrane and (2) would not rely on the activity of SLC6A8 to penetrate the brain. Here, we synthesized creatine fatty esters through original organic chemistry process. A screening on an in vitro rat primary cell-based blood-brain barrier model and on a rat primary neuronal cells model demonstrated interesting properties of these prodrugs to incorporate into endothelial, astroglial, and neuronal cells according to a structure-activity relationship. Dodecyl creatine ester showed then a 20-fold increase in creatine content in pathological human fibroblasts compared with the endogenous creatine content, stating that it could be a promising drug candidate.

  1. Crystallisation and Melting Behavior of Methyl Esters of Palm Oil

    Directory of Open Access Journals (Sweden)

    Cheng S. Foon

    2006-01-01

    Full Text Available The methyl esters of palm oil, which consists of saturated and unsaturated esters (0.6 to 95.9% unsaturation of the C12 to C18 fatty acids, solidify at the two temperature ranges, -52 to -45°C and -24 to 21°C, when the esters are cooled. When the esters are heated, they melt at two distinct temperatures, -25 and -33°C and a broad peak at -9 to 28°C. The heating thermograms also showed an exothermic crystallisation peak in between two endothermic melting peaks, indicating the occurrence of re-crystallisation of low melting methyl esters into higher melting point crystal and then melt again at higher temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Chemical Contamination Sensor for Phosphate Ester Hydraulic Fluids

    Directory of Open Access Journals (Sweden)

    Sumit Paul

    2010-01-01

    Full Text Available The paper deals with chemical contamination monitoring in phosphate-ester-based hydraulic fluids using nondispersive infrared (NDIR optical absorption. Our results show that NDIR monitoring allows detecting the take-up of water into such fluids and their hydrolytic disintegration as these become additionally stressed by Joule heating. Observations on the O–H stretching vibration band (3200–3800 cm−1 are used for determining the free water content (0–1.5% and the Total Acid Number (0–1 mgKOH/g. Both quantities can be assessed by monitoring the strength and the asymmetry of the O–H vibration band with regard to the free water absorption band centred around 3500 cm−1. As such optical parameters can be assessed without taking fluid samples from a pressurised hydraulic system, fluid degradation trends can be established based on regular measurements, before irreversible damage to the fluid has occurred. Therefore maintenance actions can be planned accordingly, which is very important for the airline, as unscheduled maintenance disturbs the flights organisation and often generates money loss.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  5. Use of citric acid esters as alternative fuel for diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Georg; Thuneke, Klaus; Remmele, Edgar [Technologie- und Foerderzentrum, Straubing (Germany); Schieder, Doris [Technische Univ. Muenchen, Straubing (Germany). Lehrstuhl fuer Chemie Biogener Rohstoffe

    2013-06-01

    Common fuels for (adapted) diesel engines are fossil diesel fuel, fatty acid methyl ester (FAME or biodiesel) or vegetable oils. Furthermore the citric acid esters tributylcitrate (TBC) and triethylcitrate (TEC) are expected to be a possible diesel substitute. Their use as fuel was applied for a patent in Germany in 2010. According to the patent applicant the advantages are low soot combustion, independence of energy imports due to the possibility of local production and a broad raw material base. Their fuel properties have been analysed in the laboratory and compared with the relevant fuel standards. Only some of the determined values are meeting the specifications, but on the other hand few rapeseed oil characteristics (e. g. oxidation stability and viscosity) can be improved if the citric acid esters are used as a blend component. The operating and emission behaviour of a vegetable oil compatible CHP unit fuelled with various rapeseed oil and TBC blends were investigated and a trouble free and soot emission reduced engine operation due to the high molecularly bound oxygen content was observed. Long term test runs are necessary for an entire technical validation. (orig.)

  6. Synthesis and characterization of novel biodegradable poly(carbonate ester)s with photolabile protecting groups.

    Science.gov (United States)

    Xie, Zhigang; Hu, Xiuli; Chen, Xuesi; Sun, Jing; Shi, Quan; Jing, Xiabin

    2008-01-01

    Novel biodegradable poly(carbonate ester)s with photolabile protecting groups were synthesized by ring-opening copolymerization of L-lactide (LA) with 5-methyl-5-(2-nitro-benzoxycarbonyl)-1,3-dioxan-2-one (MNC) with diethyl zinc (Et2Zn) as catalyst. The poly(L-lactide-co-5-methyl-5-carboxyl-1,3-dioxan-2-one) (P(LA-co-MCC)) was obtained by UV irradiation of poly(L-lactide acid-co-5-methyl-5-(2-nitro-benzoxycarbonyl)-1,3-dioxan-2-one) (P(LA-co-MNC)) to remove the protective 2-nitrobenzyl group. The free carboxyl groups on the copolymers P(LA-co-MCC) were reacted with paclitaxel, a common antitumor drug. Gel permeation chromatography and NMR studies confirmed the copolymer structures and successful attachment of paclitaxel to the copolymer.

  7. Cholesteryl esters in human malignant neoplasms.

    Science.gov (United States)

    Tosi, M R; Bottura, G; Lucchi, P; Reggiani, A; Trinchero, A; Tugnoli, V

    2003-01-01

    Cholesteryl esters (CholE) were detected in human malignant neoplasms by means of in vitro nuclear magnetic resonance spectroscopy. Spectroscopic analysis of the total lipid extracts obtained from cerebral tumors revealed appreciable amount of esterified cholesterol in high grade gliomas such as glioblastomas and anaplastic oligodendrogliomas, characterized by prominent neovascularity. The finding that no CholE were detected in the healthy brain and in low grade and benign tumors supports a possible correlation between this class of lipids and histological vascular proliferation. Compared with high grade gliomas, renal cell carcinomas show higher levels of CholE, absent in the healthy renal parenchyma and in benign oncocytomas. In nefro-carcinomas, cytoplasmic lipid inclusions and prominent vascularization contribute to the increased levels of CholE present mainly as oleate. CholE are discussed as potential biochemical markers of cancer and as a target for new therapeutic strategies.

  8. Ketone ester effects on metabolism and transcription.

    Science.gov (United States)

    Veech, Richard L

    2014-10-01

    Ketosis induced by starvation or feeding a ketogenic diet has widespread and often contradictory effects due to the simultaneous elevation of both ketone bodies and free fatty acids. The elevation of ketone bodies increases the energy of ATP hydrolysis by reducing the mitochondrial NAD couple and oxidizing the coenzyme Q couple, thus increasing the redox span between site I and site II. In contrast, metabolism of fatty acids leads to a reduction of both mitochondrial NAD and mitochondrial coenzyme Q causing a decrease in the ΔG of ATP hydrolysis. In contrast, feeding ketone body esters leads to pure ketosis, unaccompanied by elevation of free fatty acids, producing a physiological state not previously seen in nature. The effects of pure ketosis on transcription and upon certain neurodegenerative diseases make approach not only interesting, but of potential therapeutic value.

  9. Phthalate esters: heartrate depressors in the goldfish

    Energy Technology Data Exchange (ETDEWEB)

    Pfuderer, P.; Francis, A.A.

    1975-03-01

    The effect of phthalate esters isolated from carp tissue on the heart rate of goldfish is examined. Di-n-butyl phthalate, benzyl-butyl phthalate, and di-2-ethyl hexyl phthalate were previously isolated from carp tissue. It was found that the di-n-buhyl and the benzyl-butyl phthalate had significant effect on the heart rate. The effect of chloroform extracts of heart, liver, brain, kidney, gut, and remainder of fish were tested and greatest depression activity was found in the liver with some activity noted for the heart and brain. Atropine reverses the effect, so phthalate is presumed to act on the nervous system. Food chain concentration of phthalates represents a potential threat to aquatic organisms and possibly even to man. (JWP)

  10. Occurrence of 3-monochloropropanediol esters and glycidyl esters in commercial infant formulas in the United States.

    Science.gov (United States)

    Leigh, Jessica; MacMahon, Shaun

    2017-03-01

    This work presents occurrence data for fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD) and glycidol in 98 infant formula samples purchased in the United States. These contaminants are considered potentially carcinogenic and/or genotoxic, making their presence in refined oils and foods a potential health risk. Recently, attention has focused on methodology to quantify MCPD and glycidyl esters in infant formula for risk-assessment purposes. Occurrence data for 3-MCPD and glycidyl esters were produced using a procedure for extracting fat from infant formula and an LC-MS/MS method for analysing fat extracts for intact esters. Infant formulas were produced by seven manufacturers, five of which use palm oil and/or palm olein in their formulations. In formulas containing palm/palm olein, concentrations for bound 3-MCPD and glycidol ranged from 0.021 to 0.92 mg kg(-)(1) (ppm) and from < LOQ to 0.40 mg kg(-)(1) (ppm), respectively. Formulas not containing palm/palm olein, bound 3-MCPD and glycidol concentrations ranged from 0.072 to 0.16 mg kg(-)(1) (ppm) and from 0.005 to 0.15 mg kg(-)(1) (ppm), respectively. Although formulas from manufacturers A and G did not contain palm/palm olein, formulas from manufacturer E (containing palm olein) had the lowest concentrations of bound 3-MCPD and glycidol, demonstrating the effectiveness of industrial mitigation strategies.

  11. [Determination of phthalic acid esters in textiles by solid phase extraction-gas chromatography].

    Science.gov (United States)

    Niu, Zengyuan; Ye, Xiwen; Fang, Liping; Xue, Qiuhong; Sun, Zhongsong

    2006-09-01

    A method was established for the simultaneous determination of some phthalic acid esters, namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPrP), dibutyl phthalate (DBP), diamyl phthalate (DAP), dihexyl phthalate (DHP), benzyln-butyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) in textiles by solid phase extraction (SPE) coupled with gas chromatography (GC). The phthalic acid esters in textiles were extracted by Soxhlet extraction with hexane, the extracts were then cleaned up and enriched by a strong anion exchange (SAX) SPE cartridge. The parameters affecting the purification efficiency of SPE cartridge, such as solvent conditioning, rinsing, and elution, were studied. Conditioning with 5 mL hexane and rinsing with 3 mL isooctane were proved to be the optimal conditions. Of the several solvent ratios (ethylacetate in hexane) used for selective elution of phthalic acid esters from the SAX SPE cartridge, the 15% (v/v) content for ethylacetate in hexane gave the best result. Under the optimized conditions, the recoveries of phthalic acid esters for spiked standards (n=7) were 86.3%-102.7%, and the relative standard deviations (RSDs) were less than 5%. In this method the detection limits for DMP, DEP, DPrP, DBP, DAP, BBP, DCHP, DEHP, DNOP were all below 1 mg/kg, and the detection limits for DINP and DIDP were 1.74 mg/kg and 1.55 mg/kg respectively. This SPE-GC method is sensitive, accurate and suitable for the analysis of phthalate environmental hormones in textiles.

  12. Esters of ricebran oil with short chain alcohols as alternative fuel for diesel engines

    Directory of Open Access Journals (Sweden)

    F.A. Zaher

    2016-06-01

    Full Text Available The potential of ricebran oil as a feedstock for the production of a fuel for diesel engines alternative to regular diesel fuel has been assessed. Esterification rate of crude ricebran oil with methyl alcohol was studied using different volumetric ratios of alcohol to oil, different catalyst loads and catalyst types. Catalysts used were sulfuric acid at a concentration of 2% of the oil/alcohol mixture in addition to hydrochloric acid and Amberlite IR-120 cation exchange resin at the same molar concentration of H+ as in case of sulfuric acid. The reaction was fastest using sulfuric acid which has been then used to prepare esters of ricebran oil with methyl, ethyl, propyl and butyl alcohols. The four products have been evaluated as a fuel for diesel engines according to their fuel properties compared to regular diesel fuel. These properties include the calorific value, flash point, viscosity, pour point, cetane number, sulfur content and ASTM distillation characteristics. The results have shown that the methyl as well as the ethyl esters have the closest properties to those of regular diesel fuel. Diesel engine performance using blends of regular diesel fuel with methyl and ethyl esters of ricebran oil have been tested and compared to that using regular diesel fuel. The results have shown that the engine performance using a blend of 50% regular diesel fuel and 50% methyl esters of ricebran oil is better than that using regular diesel fuel. The brake thermal efficiency at full load was 30.2% using the fuel blend compared to 27.5% in case of regular fuel.

  13. Thermodynamics Calculation and Analysis of Synthesis of Dimethyl Adipate%己二酸二甲酯合成体系的热力学估算及分析

    Institute of Scientific and Technical Information of China (English)

    杨超; 魏晓霞; 霍稳周

    2011-01-01

    The group contribution method was applied to estimate the enthalpy and entropy of adipic acid and dimethyl adipate in the specified reacting system under the standard state. The functional correlations between the heat capacity of these organic compounds and temperature were established. In addition, the Gibbs free energy and standard equilibrium constant of the reaction were calculated under different temperatures. Based on the thermodynamics analysis, it's found that the reaction can be almost carried out completely when reaching the equilibrium. Therefore the conclusion that the reaction is practicable in thermodynamics has been verified.%采用基团贡献法估算了反应体系中己二酸和已二酸二甲酯在298.15 K标准状态下的生成焓和标准熵,并且估算了这两种物质的比热容随温度变化的关系式,计算了不同温度条件下反应的焓变、吉布斯自由能变和标准平衡常数.通过对该反应体系的热力学分析发现,当达到平衡时该反应几乎可以进行到底,从而验证了该反应在热力学上的可行性.

  14. Enzymatic production of alkyl esters through alcoholysis: A critical evaluation of lipases and alcohols

    DEFF Research Database (Denmark)

    Li, Deng; Xu, Xuebing; Gudmundur G, Haraldsson

    2005-01-01

    yield of FA alkyl esters, with yields well over 90% for methanol, absolute ethanol, and 1-propanol. Overall, 96% ethanol was the preferred alcohol for all lipases except Novozym 435, and ethanolysis reactions reached the maximal conversion efficiency. Increasing the water content in the system resulted...... in an increased degree of conversion for all lipases except Novozym 435. The secondary alcohol 2-propanol significantly reduced the alcoholysis reaction with all lipases; however, the branch-chain isobutanol was more advantageous than linear 1-butanol for Novozym 435, Lipozyme RM IM, and Lipase PS-C. Many...

  15. Content Analysis

    National Research Council Canada - National Science Library

    Rossi, George Bedinelli; Serralvo, Francisco Antonio; João, Belmiro Nascimento

    2014-01-01

    This study introduces the various definitions and types of content analysis. This type of analysis historically presents itself as a quantitative approach to data analysis and currently shows up as a qualitative approach...

  16. Content Marketing

    OpenAIRE

    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...

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

    Directory of Open Access Journals (Sweden)

    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

  18. Synthesis and anti-tumor activity of alkenyl camptothecin esters

    Institute of Scientific and Technical Information of China (English)

    Zhi-song CAO; John MENDOZA; Albert DEJESUS; Beppino GIOVANELLA

    2005-01-01

    Aim: To study the degrees of influence of changing side ester chains at position C20 of camptothecin on the anti-tumor activity of the molecules. Methods: The esterification reaction of camptothecin 1 and 9-nitrocamptothecin 2 with crotonic anhydride in pyridine gave the corresponding esters 3 and 4, respectively. The acylation of 1 and 2 with cinnamoyl chloride gave products 7 and 8. Epoxidation reaction of 3 and 4 with m-chloroperoxybenzoic acid in benzene solvent gave the products 5 and 6. Esters 3, 4, and 5 were tested for anti-tumor activity against 14 human cancer cell lines. Results: Both in vitro and in vivo anti-tumor activity studies for these esters were conducted and the data demonstrated positive results, that is, these esters were active against the tested tumor lines. Conclusion: Alkenyl esters 3 and 4 showed strong anti-tumor activity in vitro against 14 different cancer cell lines. Ester 3 was active against human breast carcinoma in mice and the toxicity of the agent was not observed in mice during the treatment, implying that this agent is effective for treatment with low toxicity.

  19. Precise analysis of esters content in production surroundings of vinyl chloride-vinyl acetate copolymer resins%氯醋共聚树脂生产环境空间中酯类物质含量的精密分析

    Institute of Scientific and Technical Information of China (English)

    叶滢; 康静; 李蓉

    2013-01-01

    通过改变气相色谱分析条件,提高了氯乙烯-醋酸乙烯酯共聚树脂生产环境空间中醋酸乙烯酯、丙烯酸丁酯、丙烯酸异辛酯分析结果的精密度和分析速度,对安全生产意义重大。%Through modifying the gas chromatographic analysis conditions, the analysis precision and analysis speed of contents of vinyl acetate, butyl acrylate and 2-ethylhexyl acrylate in the production sur-roundings of vinyl chloride-vinyl acetate copolymer resins were improved.The improvement had impor-tant significance for safe production.

  20. Effects of temperature and NaCl on the formation of 3-MCPD esters and glycidyl esters in refined, bleached and deodorized palm olein during deep-fat frying of potato chips.

    Science.gov (United States)

    Wong, Yu Hua; Muhamad, Halimah; Abas, Faridah; Lai, Oi Ming; Nyam, Kar Lin; Tan, Chin Ping

    2017-03-15

    The effects of frying duration, frying temperature and concentration of sodium chloride on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters (GEs) of refined, bleached and deodorized (RBD) palm olein during deep-fat frying (at 160°C and 180°C) of potato chips (0%, 1%, 3% and 5% NaCl) for 100min/d for five consecutive days in eight systems were compared in this study. All oil samples collected after each frying cycle were analyzed for 3-MCPD esters, GEs, free fatty acid (FFA) contents, specific extinction at 232 and 268 nm (K232 and K268), p-anisidine value (pAV), and fatty acid composition. The 3-MCPD ester trend was decreasing when the frying duration increased, whereas the trend was increasing when frying temperature and concentration of NaCl increased. The GEs trend was increasing when the frying temperature, frying duration and concentration of NaCl increased. All of the oil qualities were within the safety limit.

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

    NARCIS (Netherlands)

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

    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

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

    NARCIS (Netherlands)

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

    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

  3. Preparation and characterization of rosin glycerin ester and its bromide

    Institute of Scientific and Technical Information of China (English)

    Yu Caili; Zhang Faai

    2006-01-01

    Rosin glycerin ester and its bromide were prepared from natural renewable rosin,glycerin and liquid bromine which were first subjected to an esterification reaction,followed by an addition reaction.Their structures were characterized by an infrared(IR)spectrum and their thermal resistance was conducted with thermal gravity(TG)and differential scanning calorimetry(DSC).It showed that the bromide in the rosin glycerin ester decomposed faster than the ester;hence it may be used as fire-resistant material.

  4. Sugar ester surfactants: enzymatic synthesis and applications in food industry.

    Science.gov (United States)

    Neta, Nair S; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.

  5. Modular synthesis of cell-permeating 2-ketoglutarate esters.

    Science.gov (United States)

    Zengeya, Thomas T; Kulkarni, Rhushikesh A; Meier, Jordan L

    2015-05-15

    Cell-permeating esters of 2-ketoglutarate (2-KG) have been synthesized through a convergent sequence from two modules in two and three steps, respectively. This route provides access to a full series of mono- and disubstituted 2-KG esters, enabling us to define the effect of regioisomeric masking on metabolite release and antihypoxic activity in cell-based assays. In addition to providing insight into the biological activity of cell permeable 2-KG esters, the straightforward and modular nature of this synthetic route may prove useful for the development of next-generation 2-KG analogues for diagnostic and therapeutic applications.

  6. Quantification of primary fatty acid amides in commercial tallow and tallow fatty acid methyl esters by HPLC-APCI-MS.

    Science.gov (United States)

    Madl, Tobias; Mittelbach, Martin

    2005-04-01

    Primary fatty acid amides are a group of biologically highly active compounds which were already identified in nature. Here, these substances were determined in tallow and tallow fatty acid methyl esters for the first time. As tallow is growing in importance as an oleochemical feedstock for the soap manufacturing, the surfactant as well as the biodiesel industry, the amounts of primary fatty acid amides have to be considered. As these compounds are insoluble in tallow as well as in the corresponding product e.g. tallow fatty acid methyl esters, filter plugging can occur. For the quantification in these matrices a purification step and a LC-APCI-MS method were developed. Although quantification of these compounds can be performed by GC-MS, the presented approach omitted any derivatization and increased the sensitivity by two orders of magnitude. Internal standard calibration using heptadecanoic acid amide and validation of the method yielded a limit of detection of 18.5 fmol and recoveries for the tallow and fatty acid methyl ester matrices of 93% and 95%, respectively. A group of commercially available samples were investigated for their content of fatty acid amides resulting in an amount of up to 0.54%m/m (g per 100 g) in tallow and up to 0.16%m/m (g per 100 g) in fatty acid methyl esters.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylated fatty acid esters of glycerol and... esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and... additive is a mixture of esters produced by the lactylation of a product obtained by reacting edible fats...

  9. 21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Diacetyl tartaric acid esters of mono- and... acid esters of mono- and diglycerides. (a) Diacetyl tartaric acid esters of mono- and diglycerides, also know as DATEM, are composed of mixed esters of glycerin in which one or more of the hydroxyl...

  10. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glyceryl-lacto esters of fatty acids. 172.852... HUMAN CONSUMPTION Multipurpose Additives § 172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely used in food in...

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

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Bryan R.; Vaughn, Steven F. [United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N. University St, Peoria, IL 61604 (United States)

    2010-04-15

    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{sup -1}. The derived cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of CSME was 53.3, 4.21 mm{sup 2} s{sup -1} (40 C), and 14.6 h (110 C). The cold filter plugging and pour points were -15 C and -19 C, 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. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-07

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2015-04-07

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. New sucrose esters from the fruits of Physalis solanaceus.

    Science.gov (United States)

    Pérez-Castorena, Ana-Lidia; Luna, Minerva; Martínez, Mahinda; Maldonado, Emma

    2012-05-01

    Three new sucrose esters (1-3) along with several known compounds were isolated from the fruits of Physalis solanaceus. The structural elucidation of the isolates was based on their spectroscopic characteristics mainly those of MS and NMR.

  17. Caffeic glycoside esters from Jasminum nudiflorum and some related species.

    Science.gov (United States)

    Andary, C; Tahrouch, S; Marion, C; Wylde, R; Heitz, A

    1992-03-01

    Poliumoside, forsythoside B, echinacoside and arenarioside, caffeic glycoside esters, were isolated from several species of Oleaceae. The poliumoside/forsythoside ratio distinguishes Jasminum nudiflorum from J. mesnyi. Arenarioside and forsythoside B act in Forsythia species as good hybridization markers.

  18. Inert Reassessment Document for PEG Fatty Acid Esters

    Science.gov (United States)

    The tolerance reassessment decision document and action memorandum for the PEG fatty acid ester date September 28, 2005, included two tolerance exemptions (under 40 CFR 180.910 and $) CFR 180.930, respectively)

  19. α-Imino Esters in Organic Synthesis: Recent Advances.

    Science.gov (United States)

    Eftekhari-Sis, Bagher; Zirak, Maryam

    2017-06-28

    α-Imino esters are useful precursors for the synthesis of a variety of types of natural and unnatural α-amino acid derivatives, with a wide range of biological activities. Due to the adjacent ester group, α-imino esters are more reactive relative to other types of imines and undergo different kinds of reactions, including organometallics addition, metal catalyzed vinylation and alkynylation, aza-Henry, aza-Morita-Baylis-Hillman, imino-ene, Mannich-type, and cycloaddition reactions, as well as hydrogenation and reduction. This review discusses the mechanism, scope, and applications of the reactions of α-imino esters and related compounds in organic synthesis, covering the literature from the last 12 years.

  20. Synthesis of Optically Active trans-2-Aminocyclopropane-carboxylic Esters

    Institute of Scientific and Technical Information of China (English)

    Jiang Chun ZHONG; Shang Zhong LIU; Qing Hua BIAN; Ming Ming YIN; Min WANG

    2006-01-01

    Two new optically active trans-2-aminocyclopropanecarboxylic esters (β-ACCs) of optical purity 91%-96% were concisely synthesized via ozonization, oxidation, Curtius rearrangement from commercial available optically active trans-chrysanthemate in total yield 36%.

  1. Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethanes

    Directory of Open Access Journals (Sweden)

    Hiroto Hayashi

    2011-08-01

    Full Text Available Novel poly(ester-urethanes were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and a,w-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethanes. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethanes synthesized in this study showed higher Tm, Young’s modulus and tensile strength values.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Carboxylic ester hydrolases in mitochondria from rat skeletal muscle

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D; Zelander, T

    1990-01-01

    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 organophosph......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...

  5. Copper-catalyzed Decarboxylative Hydroboration: Synthesis of Vinyl Boronic Esters

    Energy Technology Data Exchange (ETDEWEB)

    Irudayanathan, Francis Mariaraj; Raja, Gabriel Charles Edwin; Kim, Han-Sung; Na, Kyungsu; Lee, Sunwoo [Chonnam National University, Gwangju (Korea, Republic of)

    2016-04-15

    Vinyl boronic esters were synthesized from aryl alkynyl carboxylic acids and bis(pinacolato)diboron using a copper-catalyzed decarboxylative reaction. The reaction was conducted with CuI (10 mol %), bis-[2-(diphenylphosphino)phenyl]ether(20 mol %), and LiOMe (20 mol %) in DMSO at 50 .deg. C for 16 h. This method provided the desired vinyl boronic esters in good-to-moderate yields and showed good functional group tolerance.

  6. Flavonol and chalcone ester glycosides from Bidens andicola.

    Science.gov (United States)

    De Tommasi, N; Piacente, S; Pizza, C

    1998-08-01

    Five new flavonol 7-O-glycosides (1-5), having quercetin or quercetin 3-methyl ether as their aglycons, and sugar chains made up of three or four sugars, including beta-D-glucopyranose, alpha-L-rhamnopyranose, and beta-D-xylopyranose, have been isolated from the aerial parts of Bidens andicola, along with a new chalcone ester glycoside (6) and five known chalcone ester glycosides. The structures of 1-6 were elucidated using a combination of spectroscopic techniques.

  7. Arylspiroboronate esters: from lithium batteries to wood preservatives to catalysis.

    Science.gov (United States)

    Vogels, Christopher M; Westcott, Stephen A

    2011-03-01

    The addition of catechol derivatives to boric acid affords a diverse family of compounds called arylspiroboronate esters. Due to boron's relatively low toxicity towards mammals, arylspiroboronate esters have several biological applications and are active for the treatment of wood against fungi and rot. These compounds are also finding increased use in organic synthesis and in catalysis. This critical review presents the synthesis, properties and applications of these remarkable compounds (149 references).

  8. Progress Report: Oxidation Stability Studies of Deuterated Esters.

    Science.gov (United States)

    1983-04-26

    esterification goes to completion and hydrolysis does not occur. *i (ii) In the presence of a catalyst (p-toluene sulphonic -" acid ), a fairly low...compounds with the antioxidant. The enhancement in oxidation stability attributable to deuteration (97%) of the acid moiety of the ester appears to be 3...meet these requirements. These esters exhibit very good thermal and oxidative stability at high temperatures (>2000C), excellent viscosity

  9. Solid state crystallisation of oligosaccharide ester derivatives

    CERN Document Server

    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...

  10. Fatty acid phytyl ester synthesis in chloroplasts of Arabidopsis.

    Science.gov (United States)

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

    2012-05-01

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

  11. Synthesis and insecticidal activities of new pyrethroid acid oxime ester derivatives

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of compounds containing oxime-ester linkage in place of the ester linkage in pyrethroid ester are designed and prepared. Bioassay data of insecticidal activities of these compounds on Ostrinia nubilalis (H.) and Culex pipines (L.) are presented. Among them 4-dimethyaminobenzaldehyde oxime ester of 2,2,3,3-tetramethylcyclopropanecarboxylic acid and 4-dimethyamino benzaldehyde oxime ester of cyclopropanecarboxylic acid are found to be potent insecticide against Ostrinia nubilalis (H.). Structure-activity relationship of the compounds is discussed.

  12. Request from the Phthalate Esters Panel of the American Chemistry Council for correction of EPA's Action Plan for Phthalate Esters

    Science.gov (United States)

    The Phthalate Esters Panel (Panel) of the American Chemistry Council submits this Request for Correction to EPA under the Guidelines for Ensuring and Maximizing the Quality, Objectivity, Utility, and Integrity, of Information Disseminated by the Environmental Protection Agency

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

    Index Scriptorium Estoniae

    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

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

    Index Scriptorium Estoniae

    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

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

    Science.gov (United States)

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

  16. Gold-catalyzed reactions of propargylic esters with vinylazides for the synthesis of Z- or E-configured buta-1,3-dien-2-yl esters.

    Science.gov (United States)

    Wagh, Sachin Bhausaheb; Liu, Rai-Shung

    2015-10-28

    Gold-catalyzed synthesis of buta-1,3-dien-2-yl esters by the reaction of propargyl esters with vinylazides is described; the reaction mechanism is postulated to involve a vinyl attack of vinylazides at alkenyl gold carbenes.

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

    Science.gov (United States)

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

    2006-02-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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%.

  20. Analysis of the alcohols, esters and carbonyl compounds in fusel oil samples; Analise dos alcoois, esteres e compostos carbonilicos em amostras de oleo fusel

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Eduardo R.; Cardoso, Daniel R.; Franco, Douglas W. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica. Dept. de Quimica e Fisica Molecular. E-mail: douglas@iqsc.sc.usp.br

    2001-02-01

    Analysis of alcohols, esters and carbonyl compounds were performed using HRGC and HPLC techniques in samples of fusel oils from three different Brazilian alcohol distilleries. High content of isoamyl alcohol (390 deg c g.L{sup -1})., isobutyl alcohol (158 g.L{sup -1}), ethyl alcohol (28,4 g.L{sup -1}), methyl alcohol (16,6 g.L{sup -1}) and n-propyl alcohol (11,9 g.L{sub -}{sup 1}) were found. These compounds represent 77 {+-} 8% of the approximated weight of a liter of fusel oils. The obtained results show the feasibility of using fusel oils as low-cost raw material for the synthesis of chemicals. (author)

  1. Optimized Li-Ion Electrolytes Containing Fluorinated Ester Co-Solvents

    Science.gov (United States)

    Prakash, G. K. Surya; Smart, Marshall; Smith, Kiah; Bugga, Ratnakumar

    2010-01-01

    A number of experimental lithium-ion cells, consisting of MCMB (meso-carbon microbeads) carbon anodes and LiNi(0.8)Co(0.2)O2 cathodes, have been fabricated with increased safety and expanded capability. These cells serve to verify and demonstrate the reversibility, low-temperature performance, and electrochemical aspects of each electrode as determined from a number of electrochemical characterization techniques. A number of Li-ion electrolytes possessing fluorinated ester co-solvents, namely trifluoroethyl butyrate (TFEB) and trifluoroethyl propionate (TFEP), were demonstrated to deliver good performance over a wide temperature range in experimental lithium-ion cells. The general approach taken in the development of these electrolyte formulations is to optimize the type and composition of the co-solvents in ternary and quaternary solutions, focusing upon adequate stability [i.e., EC (ethylene carbonate) content needed for anode passivation, and EMC (ethyl methyl carbonate) content needed for lowering the viscosity and widening the temperature range, while still providing good stability], enhancing the inherent safety characteristics (incorporation of fluorinated esters), and widening the temperature range of operation (the use of both fluorinated and non-fluorinated esters). Further - more, the use of electrolyte additives, such as VC (vinylene carbonate) [solid electrolyte interface (SEI) promoter] and DMAc (thermal stabilizing additive), provide enhanced high-temperature life characteristics. Multi-component electrolyte formulations enhance performance over a temperature range of -60 to +60 C. With the need for more safety with the use of these batteries, flammability was a consideration. One of the solvents investigated, TFEB, had the best performance with improved low-temperature capability and high-temperature resilience. This work optimized the use of TFEB as a co-solvent by developing the multi-component electrolytes, which also contain non

  2. 己二酸-1,4-丁二醇-尿素共聚物的合成与表征%Synthesis, characterization of adipic acid-l, 4-butanediol-urea copolymer

    Institute of Scientific and Technical Information of China (English)

    刘跃军; 谢伟; 刘亦武; 刘磅

    2012-01-01

    A novel adipic acid copolymer was synthesized via condensation polymerization with adipic acid, urea and, 1,4-butanediol as the raw materials. The influences of reaction time, catalyst, mass ratio of raw materials and the temperature on the property of copolymer were investigated. The structure, thermodynamic perform- ance and the molecular weights of the eopolymer were characterized by fourier transform infrared (FT-IR), 1 H- NMR spectrum, gel permeation chromatography (GPG) and thermogravimeter-differential scanning calorimeter (TG-DSC) respectively. The results show that under the condition of 220℃, 10h, the optimal feed molar ratios n (1,4-butanediol and urea)/n (adipic acid) == 1.16 : 1, n (adipie acid)/n (urea) = 5 : 1, the amount of catalyst was 0.03wt %), a desired adipic acid copolymer whose weight-average molecular weight reaches 12700 could be obtained. The prepared copolymer has higher thermostability, degradability and good appearance.%以己二酸、1,4-丁二醇和尿素为原料,在氩气环境下,通过高温熔融缩聚反应合成了一种新型可降解的己二酸-丁二醇-尿素共聚物,并对反应时间、催化剂种类及其用量、原料配比、反应温度等因素对聚合产物的影响进行了研究。采用红外光谱(FT-IR)、核磁共振(1H-NMR)、凝胶渗透色谱(GPC)、热重分析(TG)、差示量热扫描(DSC)对产物的结构与性能进行了表征。结果表明,当丁二醇和尿素的总量与己二酸(n(丁二醇+尿素)∶n(己二酸))的摩尔比为1.16∶1,丁二醇和尿素(n(1,4-丁二醇)∶n(尿素))的摩尔比为5∶1,最高反应温度为220℃,二月桂酸二丁基锡为催化剂且用量为原料总量的0.03%,总反应时间10h,所得到产物的重均分子量(Mw)可达12700,其颜色、热稳定性和降解性能等较好。

  3. Flow-induced crystallization of a nano composite of poly(butylene adipate-co-terephthalate)/montmorillonite; Cinetica de cristalizacao induzida por fluxo de nanocomposito de poli(butileno adipato-co-tereftalato)/montmorilonita

    Energy Technology Data Exchange (ETDEWEB)

    Bonel, Alan B. [Universidade Federal de Sao Carlos. UFSCar, Departamento de Engenharia de Materiais DEMa, SP (Brazil); Rego, Bruna T.; Beatrice, Cesar A.G.; Marini, Juliano; Bretas, Rosario E.S., E-mail: bretas@ufscar.br [Universidade Federal de Sao Carlos. UFSCar, Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais, SP (Brazil)

    2011-07-01

    Poly(butylene adipate-co-terephthalate) (PBAT) with 5wt% of an organically modified montmorillonite with polar surfactant was prepared by melt blending in a co-rotational twin-screw extruder at 160 degree C. 100rpm and 1 kg/h. Both pure polymer and nano composite were characterized by wide measurements. The study of the flow-induced crystallization was also done by rheological measurements, monitoring the viscosity as a function of time. The nano clay's lamellas were intercalated in the polymer m loss moduli of the nano composite, at low frequencies, showed that the particles of the nano clay were well dispersed and distributed thru the PBAT matrix. Finally, the presence of the nano clay's particles reduced the induction tim crystals growth, due to the strong interactions with the PBAT chains. (author)

  4. 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)

    Energy Technology Data Exchange (ETDEWEB)

    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)

  5. Influence of the addition of bentonite clay in poli (butylene adipate co-terephthalic) / poly(lactic acid) membranes; Influencia da adicao de argila bentonita em membranas de poli(butileno adipato co-tereftalico)/poli(Acido latico)

    Energy Technology Data Exchange (ETDEWEB)

    Morais, D.D.S.; Medeiros, K.M.; Araujo, E.M.; Melo, T.J.A. [Universidade Federal de Campina Grande (UAEMa/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Barbosa, R., E-mail: dayannediniz@hotmail.com [Universidade Federal do Piaui (CT/UFPI), PI (Brazil). Centro de Tecnologia

    2014-07-01

    The processes of membrane separation have been used in many different sectors of industrial activity, ranging from the chemical industry, food, pharmaceutical, medical and biotech. In this paper, a bentonite clay was added by melt intercalation in a poly(butylene adipate-co-terephthalic acid)/poly(lactic acid) blend at levels 1 and 3 wt% of clay. After that, membranes were produced by solvent evaporation technique. From the XRD results, it was verified the possible formation of exfoliated/partially exfoliated structures in the membranes. By DSC, it was observed that the addition of clay did not promote alterations in glass transition temperature and crystalline melting of the PBAT/PLA matrix. The morphology of the membranes were observed by SEM and it was verified the clay formation of porous membranes. (author)

  6. Sorption of organophosphate esters by carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. VARTM工艺用乙烯基酯树脂基体配方及性能研究%PROPORTIONINGS AND PROPERTIES OF VINYL ESTER RESINS FOR VARTM

    Institute of Scientific and Technical Information of China (English)

    刘发杰; 李华; 魏化震; 王慧军; 丁笑晖; 惠林海

    2011-01-01

    以溴化改性乙烯基酯树脂、氨基甲酸酯改性乙烯基酯树脂为混合基体,以E-玻璃纤维(GF)为增强材料,通过真空辅助树脂传递模塑(VARTM)工艺制备乙烯基酯树脂/GF复合材料,对其力学性能和阻燃性能进行了研究.结果表明,在两种树脂质量比为1:1时该复合材料的拉伸强度与弯曲强度达到最大值,且综合性能最优.氧指数随溴化改性乙烯基酯树脂含量的增加而增加.%Based on the duplex matrix of bromized vinyl ester resin and carbamic vinyl ester resin, reinforced by E - glass fiber( GF), vinyl ester resin/GF composites were prepared with VARTM. Mechanical properties and flame retardancy of vinyl ester resin/GF composites were studied. The result showed that the tensile strength and fiexural strength of the composite achieved the maximum and had the best multipurpose properties when the weight ratio of the two resins was 1:1, and the oxygen index increased as the increasing of bromized vinyl ester resin content.

  8. MAIN CONTENTS

    Institute of Scientific and Technical Information of China (English)

    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

  9. Content Analysis

    Directory of Open Access Journals (Sweden)

    George Bedinelli Rossi

    2014-09-01

    Full Text Available This study introduces the various definitions and types of content analysis. This type of analysis historically presents itself as a quantitative approach to data analysis and currently shows up as a qualitative approach. The most common types are the conceptual and relational analysis. The latter receives influences of linguistic, cognitive and mental models and it is subdivided in affective extraction, analysis of proximity and cognitive mapping. Regarding the importance of this type of analysis, we have quantitative and qualitative character and the latter approach can be used to identify hypotheses, theoretical constructs or even models that can be tested by multivariate statistical techniques or even by experiments. 

  10. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl and ethyl esters of fatty acids produced... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters... following prescribed conditions: (a) The additive consists of a mixture of either methyl or ethyl esters of...

  11. A process for high yield and scaleable recovery of high purity eicosapentaenoic acid esters from microalgae and fish oil.

    Science.gov (United States)

    Belarbi; Molina; Chisti

    2000-04-01

    A low expense process is developed for recovering esterified eicosapentaenoic acid (EPA) from microalgae and fish oil. Over 70% of the EPA content in the esterified crude extract of microalgae were recovered at purities exceeding 90%. The recovery scheme utilizes either wet or freeze-dried algal biomass. The process consists of only three main steps: 1) simultaneous extraction and transesterification of the algal biomass; 2) argentated silica gel column chromatography of the crude extract; and 3) removal of pigments by a second column chromatographic step. Argentated silica gel chromatography recovered about 70% of the EPA ester present in the crude fatty ester mixture of fish oil, but at a reduced purity ( approximately 83% pure) compared to the microalgal derived EPA. The optimal loading of the fatty ester mixture on the chromatographic support was about 3% (w/w) but loadings up to 4% did not affect the resolution significantly. The process was scaled up by a factor of nearly 320 by increasing the diameter of the chromatography columns. The elution velocity remained constant. Compared to the green alga Monodus subterraneus, the diatom Phaeodactylum tricornutum had important advantages as a potential commercial producer of EPA. For a microalgal EPA process to be competitive with fish oil derived EPA, P. tricornutum biomass (2.5% w/w EPA) needs to be obtained at less than $4/kg. If the EPA content in the alga are increased to 3.5%, the biomass may command a somewhat higher price. The quality of microalgal EPA compares favorably with that of the fish oil product. Compared to free fatty acid, EPA ester is more stable in storage. Shelf-life is extended by storing in hexane. The silver contamination in the final purified EPA was negligibly small (<210 ppb).

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

    Science.gov (United States)

    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

  13. COMBUSTION CHARACTERISTICS OF DIESEL ENGINE OPERATING ON JATROPHA OIL METHYL ESTER

    Directory of Open Access Journals (Sweden)

    Doddayaraganalu Amasegoda Dhananjaya

    2010-01-01

    Full Text Available Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as jatropha oil, linseed oil, mahua oil, rice bran oil, karanji oil, etc., are potentially effective diesel substitute. Vegetable oils have reasonable energy content. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in diesel engines with very little or no engine modifications. This is because it has combustion characteristics similar to petroleum diesel. The current paper reports a study carried out to investigate the combustion, performance and emission characteristics of jatropha oil methyl ester and its blend B20 (80% petroleum diesel and 20% jatropha oil methyl ester and diesel fuel on a single-cylinder, four-stroke, direct injections, water cooled diesel engine. This study gives the comparative measures of brake thermal efficiency, brake specific energy consumption, smoke opacity, HC, NOx, ignition delay, cylinder peak pressure, and peak heat release rates. The engine performance in terms of higher thermal efficiency and lower emissions of blend B20 fuel operation was observed and compared with jatropha oil methyl ester and petroleum diesel fuel for injection timing of 20° bTDC, 23° bTDC and 26° bTDC at injection opening pressure of 220 bar.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Development of continuous deglycerolisation reactor for ethyl ester production

    Directory of Open Access Journals (Sweden)

    Ruamporn Nikhom

    2014-12-01

    Full Text Available In this work, the development of continuous deglycerolisation (CD reactor for ethyl ester production was investigated to improve the ethyl ester conversion. The device to assist separation of glycerol, in the CD unit, integrates transesterification (mixing zone and separation (settling zone into one unit. For reversible transesterification, removing glycerol during reaction can drive the equilibrium to the product side in order to achieve high conversion. Two models of device to assist separation of glycerol have been carried out to investigate the suitable conditions for ethyl ester production. Results showed that the fin-type model could separate higher amount of glycerol from the reaction system in order to achieve high transesterification conversion. The suitable conditions found in this study were: molar ratio of oil to ethanol of 1:5, KOCH3 concentration of 1.6 %wt. retention time of 15 min and reaction temperature of 70°C. At these conditions, ethyl ester’s purity and yield were 97.3%wt. and 92.0%wt., respectively. In addition, the fuel properties of the final ethyl ester product met the biodiesel standard for methyl ester which specified by Department of Energy Business.

  16. Mechanism of Imidazole-Promoted Ligation of Peptide Phenyl Esters

    Institute of Scientific and Technical Information of China (English)

    王晨; 刘磊

    2012-01-01

    Imidazole-promoted ligation of peptide phenyl esters was recently found to be a complementary method for protein chemical synthesis. Theoretical calculations have been carried out to understand the detailed mechanism of this particular ligation process. It is found that both the reaction of the phenyl ester with imidazole and the reaction of the acyl imidazole intermediate with cysteine proceed through an addition-elimination mechanism. The cleavage of the C--O bond in the reaction between the phenyl ester and imidazole is the rate-limiting step of the overall liga- tion process. Interestingly, although the imidazole-promoted phenyl ester ligation has a higher free energy barrier than the conventional thiophenol-promoted native chemical ligation for a sterically less hindered C-terminal amino acid (e.g. gylcine), for a sterically hindered C-terminal amino acid (e.g. proline) the imidazole-promoted phenyl ester ligation is calculated to be more favorable than the conventional thiophenol-promoted native chemical ligation.

  17. Microwave-Assisted Synthesis of Cinnamyl Long Chain Aroma Esters.

    Science.gov (United States)

    Worzakowska, Marta

    2015-06-08

    Cinnamyl long chain aroma esters were prepared by using the conventional and microwave-assisted methods. The esterification reaction of naturally occurring 3-phenyl-prop-2-en-1-ol and different chain lengths acidic and diol reagents was carried out at the temperature of 140 °C under solvent free conditions. As acidic reagents, oxolane-2,5-dione, oxane-2,6-dione, hexanedioic acid and decanedioic acid were applied. Ethane-1,2-diol and 2,2'-[oxybis(2,1-ethandiyloxy)]diethanol were used as diol reagents. The synthesis of high molecular mass cinnamyl esters under conventional method conditions requires a long time to obtain high yields. The studies confirm that by using microwave irradiation, it is possible to reduce the reaction times to only 10-20 min. The structures of prepared esters were confirmed on the basis of FTIR, 1H-NMR and 13C-NMR. In addition, the newly obtained cinnamyl long chain esters were tested for their thermal properties. The TG studies proved the high thermal resistance of the obtained esters under inert and oxidative conditions.

  18. Specificity of Mucor miehei lipase on methyl ester substrates

    Directory of Open Access Journals (Sweden)

    Pina, M.

    1993-12-01

    Full Text Available Fatty acid methyl esters constitute a good substrate for the characterization of lipase typospecificity. In the present work, the hydrolytic action of lipase from Mucor miehei was studied. It was demonstrated that this lipase preferentially catalyses the hydrolysis of fatty acid methyl esters with small number of double bonds. It was also found that this lipase shows a specificity in the hydrolysis of fatty acid methyl esters with short aliphatic chain.Los esteres metílicos de ácidos grasos constituyen un buen sustrato para la caracterización de tipos de especificidad de lipasa. En el presente trabajo, se estudió la acción hidrolítica de lipasa de Mucor miehei. Se demostró que esta lipasa cataliza preferencialmente la hidrólisis de esteres metílicos de ácidos grasos con número pequeño de dobles enlaces. Se encontró también que esta lipasa muestra una especificidad en la hidrólisis de ásteres metílicos de ácidos grasos con cadena alifática corta.

  19. Fragrance material review on carbonic acid, methyl phenylmethyl ester.

    Science.gov (United States)

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of carbonic acid, methyl phenylmethyl ester when used as a fragrance ingredient is presented. Carbonic acid, methyl phenylmethyl ester is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for carbonic acid, methyl phenylmethyl ester were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Effect of temperature stress on protein methyl esters

    Energy Technology Data Exchange (ETDEWEB)

    Welch, W.; Kracaw, K.

    1986-05-01

    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-/sup 3/H)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 (/sup 3/H)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.

  1. Solid state crystallisation of oligosaccharide ester derivatives

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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.

  3. Vinylic polymerization of Norbornenecarboxylic Acid Esters by Palladium Complexes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    New thermoplastic norbornene polymers containing ester groups were prepared byvinylic polymerization of norbornene-carboxylic acid esters by Pd(Ⅱ)-based catalysts. Themonomers were obtained by Diels-Alder reaction of cyclopentadiene with acrylic acid esters(methyl and butyl) as mixtures of endo/exo (ratio 40/60)-isomers and were converted topolymers in 60%~70% conversion. The endo-isomer was less reactive than the exo-isomer.To obtain higher molecular weight the more reactive pure exo-isomer was prepared andpolymerized with the Pd (Ⅱ)-catalysts, tetrakis (acetonitrile) Pd (Ⅱ) bis (tetrafluoroborate)and (η3-allyl)Pd(Ⅱ)SbF6, in high conversion. These polymers showed high glass transitiontemperatures, high transparency and good solubility in common solvents.

  4. Ester oxidation on an aluminum surface using chemiluminescence

    Science.gov (United States)

    Jones, William R., Jr.; Meador, Michael A.; Morales, Wilfredo

    1986-01-01

    The oxidation characteristics of a pure ester (trimethyolpropane triheptanoate) were studied by using a chemiluminescence technique. Tests were run in a thin film microoxidation apparatus with an aluminum alloy catalyst. Conditions included a pure oxygen atmosphere and a temperature range of 176 to 206 C. Results indicated that oxidation of the ester (containing .001 M diphenylanthracene as an intensifier) was accompanied by emission of light. The maximum intensity of light emission was a function of the amount of ester, the concentration of intensifier, and the test temperature. The induction period, or the time to reach one-half of maximum intensity was inversely proportional to test temperature. Decreases in light emission at the later stages of a test were caused by depletion of the intensifier.

  5. Microwave-assisted preparation of naphthenic acid esters

    Directory of Open Access Journals (Sweden)

    VERA CIRIN-NOVTA

    2006-12-01

    Full Text Available The synthesis of esters of natural petroleum acids of the naphthenic type assisted with microwave irradiation under the conditions of acid catalysis was carried out with various alcohols: methanol, ethanol, n-butanol and tert-butyl alcohol. Microwave dielectric heating of the reaction mixture in an unmodified microwave oven with activation of the naphthenic acids with sulfuric and p-toluenesulfonic acid afforded the esters of the naphthenic acids. Depending on the catalyst and the steric and nucleophilic properties of the alcohols, the yield of naphthenic esters ranged from 31.25 % to 88.90 %. As a consequence of microwave dielectric heating, the esterification time was reduced from 6–10 h to 5 min.

  6. Long-Acting Diclofenac Ester Prodrugs for Joint Injection

    DEFF Research Database (Denmark)

    Mertz, Nina; Larsen, Susan Weng; Kristensen, Jesper

    2016-01-01

    A prodrug approach for local and sustained diclofenac action after injection into joints based on ester prodrugs having a pH-dependent solubility is presented. Inherent ester prodrug properties influencing the duration of action include their pH-dependent solubility and charge state, as well...... as susceptibility to undergo esterase facilitated hydrolysis. In this study, physicochemical properties and pH rate profiles of 3 diclofenac ester prodrugs differing with respect to the spacer carbon chain length between the drug and the imidazole-based promoiety were determined and a rate equation for prodrug...... degradation in aqueous solution in the pH range 1-10 was derived. In the pH range 6-10, the prodrugs were subject to parallel degradation to yield diclofenac and an indolinone derivative. The prodrug degradation was found to be about 6-fold faster in 80% (vol/vol) human plasma as compared to 80% (vol...

  7. Electron driven processes in chlorodifluoroacetic acid methyl ester

    Science.gov (United States)

    Kopyra, Janina

    2014-07-01

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

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

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.

    2004-01-01

    , medical devices and toys may harm the e.g. reproductive organs of exposed infants. PVC is readily distinguished from other common polymers (e.g. polyethylene, polypropylene, polystyrene) by the use of Raman spectroscopy. By far the most commonly used phthalate plasticizer in PVC is di(2-ethylhexyl......Polyvinyl chloride, PVC or [CH2-CHCl]n , is a common polymer used extensively for a wide range of industrial and household products. To achieve the proper material characteristics (e.g. softness, ductility), plasticizers such as phthalates are usually added to the otherwise hard and brittle PVC...

  9. Stimulation of chicken growth hormone release by phorbol esters.

    Science.gov (United States)

    Perez, F M; Malamed, S; Scanes, C G

    1990-11-01

    Synergism between thyrotropin-releasing hormone (TRH) and human pancreatic growth hormone-releasing factor (hpGRF) has been shown in a primary (48 hr) culture of chicken adenohypophyseal cells established in this laboratory. The purpose of the present study was to determine if phorbol esters acting alone or in concert with TRH or hpGRF affect chicken GH release. Collagenase-dissociated chicken adenohypophyseal cells were treated (2 hr) with combinations of TRH, hpGRF, phorbol esters (activators of protein kinase C; PKC), and pharmacologic agents that increase cAMP. Phorbol myristate acetate (PMA) or phorbol dibutyrate (PDBu) alone stimulated GH release in a dose-dependent manner; either phorbol ester (10(-6) M) increased GH release from 100 to 390% over the value obtained in the absence of test agents (control). Similarly, hpGRF (10(-9) M), 8 Br-cAMP (10(-3) M), forskolin (10(-6) M), or isobutylmethylxanthine (IBMX, 10(-3) M) alone elevated GH release by at least 60% over the control value. The combined effects of phorbol esters (either PMA or PDBu) and hpGRF, 8 Br-cAMP, or forskolin on GH release were additive. Only one combination, phorbol esters with IBMX, exerted synergistic effects on GH release. No synergy was shown between TRH (1.3 x 10(-9) M) and either phorbol ester. These findings are the first to implicate PKC in chicken GH release in vitro. In addition, these studies, together with previous results, suggest that TRH and hpGRF synergy occurs via a pathway that arises prior to activation of PKC.

  10. ABCA12 maintains the epidermal lipid permeability barrier by facilitating formation of ceramide linoleic esters.

    Science.gov (United States)

    Zuo, Ying; Zhuang, Debbie Z; Han, Rong; Isaac, Giorgis; Tobin, Jennifer J; McKee, Mary; Welti, Ruth; Brissette, Janice L; Fitzgerald, Michael L; Freeman, Mason W

    2008-12-26

    Harlequin ichthyosis is a congenital scaling syndrome of the skin in which affected infants have epidermal hyperkeratosis and a defective permeability barrier. Mutations in the gene encoding a member of the ABCA transporter family, ABCA12, have been linked to harlequin ichthyosis, but the molecular function of the protein is unknown. To investigate the activity of ABCA12, we generated Abca12 null mice and analyzed the impact on skin function and lipid content. Abca12-/- mice are born with a thickened epidermis and die shortly after birth, as water rapidly evaporates from their skin. In vivo skin proliferation measurements suggest a lack of desquamation of the skin cells, rather than enhanced proliferation of basal layer keratinocytes, accounts for the 5-fold thickening of the Abca12-/- stratum corneum. Electron microscopy revealed a loss of the lamellar permeability barrier in Abca12-/- skin. This was associated with a profound reduction in skin linoleic esters of long-chain omega-hydroxyceramides and a corresponding increase in their glucosyl ceramide precursors. Because omega-hydroxyceramides are required for the barrier function of the skin, these results establish that ABCA12 activity is required for the generation of long-chain ceramide esters that are essential for the development of normal skin structure and function.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  12. On the nature of ionic liquids and their effects on lipases that catalyze ester synthesis.

    Science.gov (United States)

    De Diego, Teresa; Lozano, Pedro; Abad, Miguel A; Steffensky, Katharina; Vaultier, Michel; Iborra, José L

    2009-03-25

    Free and immobilized lipases from Candida antarctica (CALA and CALB), Thermomyces lanuginosus (TLL) and Rhizomucor miehei (RML) were used as catalysts in the synthesis of butyl propionate by transesterification in reaction media consisting in nine different ionic liquids. Enzyme activities were clearly dependent on the nature of the ions, the results being improving as the alkyl chain length of the imidazolium cation increased, and as a function of the type of anion ([PF(6)], [BF(4)] or [ethylsulphate]). The best synthetic activity (655.5U/mg protein at 40 degrees C) was obtained when free CALB were assayed in the water-miscible IL cocosalkyl pentaethoxy methyl ammonium methosulfate ([CPMA][MS]), and was clearly related with the water content of the medium. The synthetic activity of free CALB in [CPMA][MS] was enhanced with the increase in temperature, while practically no effect was obtained for TLL. The ability of free CALB to synthesize aliphatic esters of different alkyl chain lengths, using different alkyl vinyl esters and 1-alkanols as substrates, was also studied in [CPMA][MS], the best results (4500U/mg protein) being obtained for the synthesis of hexyl butyrate.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Lipase catalyzed synthesis of organic acid esters of lactic acid in non-aqueous media.

    Science.gov (United States)

    Kiran, K R; Divakar, S

    2001-05-04

    Lipases from Rhizomucor miehei (Lipozyme IM20) and porcine pancreas (PPL) were employed as catalysts for the esterification reaction between the hydroxyl group of lactic acid and the carboxyl group of organic acids. Reactions were carried out at both shake-flask and bench-scale levels. Various parameters, such as solvent, temperature, substrate and enzyme concentrations, effect of buffer volume, buffer pH and water volume, were investigated for optimization of yields. While ethylmethyl ketone (EMK) was found to be the best solvent for shake-flask reactions, chloroform gave higher yields at bench-scale level. Detailed studies were carried out with respect to the synthesis of palmitoyl and stearoyl lactic acids. At shake-flask level, maximum yields of 37.5 and 40% were observed in case of palmitoyl and stearoyl lactic acids, respectively, with Lipozyme IM20; at bench-scale level, the maximum yields were 85.1 and 99% respectively, when PPL was employed. Of all the organic acids employed (C(2)--C(18)), only lauric, palmitic and stearic acids gave yields above 50%. At bench-scale level, PPL could be reused for up to three cycles with yields above 40%. Esters prepared were found to conform to Food Chemical Codex (FCC) specifications in terms of acid value, ester value, sodium and lactic acid contents.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Directory of Open Access Journals (Sweden)

    Sivalakshmi S.

    2011-01-01

    Full Text Available 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 full load, peak cylinder pressure is higher for NOME; peak heat release rate during the premixed combustion phase is lower for neat NeO and NOME. Ignition delay is lower for neat NeO and NOME when compared with diesel at full load. The brake thermal efficiency is slightly lower for NeO at all engine loads, but in the case of NOME slightly higher at full load. It has been observed that there is a reduction in NOx emission for neem oil and its methyl ester along with an increase in CO, HC and smoke emissions.

  17. High plasma cholesteryl ester transfer but not CETP mass predicts incident cardiovascular disease : A nested case control study

    NARCIS (Netherlands)

    Kappelle, Paul J.W.H.; Perton, Frank; Hillege, Hans L.; Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.

    Objective: The relationship of cardiovascular disease (CVD) with plasma cholesteryl ester transfer protein (CETP) levels is controversial. We determined whether plasma cholesteryl ester transfer (CET), reflecting CETP-mediated transfer of cholesteryl esters from endogenous HDL towards apolipoprotein

  18. Triterpene Galloyl Esters from Edible Acorn of Castanopsis cuspidata.

    Science.gov (United States)

    Ogata, Misaki; Saito, Yoshinori; Matsuo, Yosuke; Maeda, Hajime; Tanaka, Takashi

    2016-02-01

    Polyphenols of edible acorns of Castanopsis cuspidata were examined and two triterpene galloyl esters were isolated. Based on two-dimensional NMR spectroscopic evidence the structures were determined to be 3,24-di-O-galloyl-2α,3β-23,24-tetrahydroxyolean-12-en-28-oic acid (1) and 3,24-di-O-galloyl- 2α,3β-23,24-tetrahydroxyurs-12-en-28-oic acid (2). The triterpene hexahydroxydiphenoyl esters, which had been found in the leaves, were not detected in the acorns.

  19. Alkyl polyglycoside-sorbitan ester formulations for improved oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Iglauer, S.; Shuler, P.; Tang, Y. [Power Environmental Energy Research Institute (PEERI), Covina, CA (United States); Goddard, W.A. III [California Inst. of Technology, Pasadena, CA (US). Div. of Chemistry and Chemical Engineering, Materials and Process Simulation Center (MSC)

    2010-09-15

    We measured interfacial tensions (IFT) of aqueous alkyl polyglucoside (APG) systems formulated with sorbitan ester-type cosurfactants against n-octane. The study focused on low to ultra-low IFT systems which are relevant for enhanced oil recovery (EOR). In addition, we measured equilibrium adsorption concentrations of these surfactants and cosurfactants onto kaolinite clay, commonly found in oil reservoirs. We present one surfactant EOR laboratory flood experiment with one selected APG-sorbitan ester formulation with which we recovered 94% of initial oil in place (IOIP). (orig.)

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

    Indian Academy of Sciences (India)

    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.

  1. Switchable Surface Wettability by Using Boronic Ester Chemistry.

    Science.gov (United States)

    Taleb, Sabri; Noyer, Elisabeth; Godeau, Guilhem; Darmanin, Thierry; Guittard, Frédéric

    2016-01-18

    Here, we report for the first time the use of a boronic ester as an efficient tool for reversible surface post-functionalization. The boronic ester bond allows surfaces to be reversibly switched from hydrophilic to hydrophobic. Based on the well-known boronic acid/glycol affinity, this strategy offers the opportunity to play with surface hydrophobic properties by adding various boronic acids onto substrates bearing glycol groups. The post-functionalization can then be reversed to regenerate the starting glycol surface. This pathway allows for the preparation of various switchable surfaces for a large range of applications in biosensors, liquid transportation, and separation membranes.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. Study of rosin glycerol esters as microencapsulating materials.

    Science.gov (United States)

    Pathak, Y V; Dorle, A K

    1985-01-01

    Rosin esters were prepared by heating rosin with glycerol and intermediate reaction products with different acid values were withdrawn. Salicylic acid granules were encapsulated using a 10 per cent solution of rosin esters in acetone. The coated microcapsules were evaluated for moisture absorption, flow properties and dissolution studies. The results showed that rosin and rosin-glycerol intermediates with acid values of 122, 105 and 55 had excellent moisture protection properties. Dissolution studies showed that these could be used for delayed release of drug.

  4. Kinetically controlled synthesis of monoglyceryl esters from chiral and prochiral acids methyl esters catalyzed by immobilized Rhizomucor miehei lipase.

    Science.gov (United States)

    Acosta, Andreina; Filice, Marco; Fernandez-Lorente, Gloria; Palomo, Jose M; Guisan, Jose M

    2011-01-01

    Partial acylation of only one primary hydroxyl group of glycerol generates a chiral center at position 2. Rhizomucor miehei lipase (RML) catalyzes the kinetically controlled transesterification of different aromatic carboxylic acids methyl esters with glycerol. High synthetic yields of glyceryl esters (around 70-80%) were obtained even in the presence of significant concentrations of water (from 5% to 20%). After a long incubation of the reaction mixture in the presence of the biocatalyst only pure free acid was obtained. Other lipases (from Geobacillus thermocatenulatus and from Thermomyces lanuginose) also catalyzed similar kinetically controlled transesterifications although less efficiently. RML immobilized on Sepharose-Q showed a high activity and specificity, compared to the immobilization by other techniques, only producing monoglyceryl esters with all substrates. In particular, monoglyceryl-phenylmalonate product was synthesized in 82% overall yield and >99% diastereomeric excess at pH 7.0 and 37°C and 90% glycerol.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  8. Estudi del canal de glicerol aqp7 i de l'adipoquina zag en l'àmbit de l'obesitat, la diabetis tipus 2 i la síndrome metabòlica. Dues proteïnes implicades en la lipòlisi del teixit adipós

    OpenAIRE

    Ceperuelo Mallafré, Mª Victòria

    2010-01-01

    L'obesitat incrementa les possibilitats de patir altres malalties com la diabetis mellitus tipus 2 (DM2), la dislipèmia, la hipertensió, entre d'altres. Per tal de poder avançar en noves dianes terapèutiques que millorin aquestes malalties és necessari conèixer millor la biologia del teixit adipós i els seus components. El teixit adipós blanc, a més a més d'emmagatzemar la major part de les reserves energètiques, és capaç de tenir activitat metabòlica i endocrina. Cal tenir en compte que un ...

  9. Effect of Nitrate Ester on the Combustion Characteristics of PET/HMX -based Propellants

    Directory of Open Access Journals (Sweden)

    Yunlan Sun

    2011-04-01

    Full Text Available The effect of nitrate ester NG/TEGDN on the combustion characteristics of PET/HMX-based propellants has been experimentally investigated using of high-speed photography technique and scanning electron microscopy. It is indicated that the increase of NG/TEGDN content has little impact on the propellant burning rates at the same pressure. Furthermore, propellant can not be self-sustaining combustion at low pressure (£1 MPa. The increase of NG/TEGDN content does not affect the flame structure of propellant, but it plays an important role in condensed phase reaction zone. The flame structure of propellant is estimated. The thermal decomposition products in different combustion zones are also discussed. Scanning electron microscopy examination of quenched sample indicates that a liquified layer forms during combustion of these propellants. Numerous gas bubbles are present. Especially, the burning surface of propellant with low NG/TEGDN content shows signs of crystallization. The thickness of condensed phase reaction zone, by cross-section examination of propellant burning surface, has also been investigated. The results show that the thickness of condensed phase reaction zone increases with NG/TEGDN content increasing. These observations suggest that the condensed phase zone plays significant role in propellant combustion.Defence Science Journal, 2011, 61(3, pp.206-213, DOI:http://dx.doi.org/10.14429/dsj.61.567

  10. Modification of poly (butylene succinate-co-butylene adipate) (PBSA) by physical blending with poly (1,2-propylene succiate) (PPSu)%聚(丁二酸-1,2-丙二酯)(PPSu)对聚(丁二酸丁二酯-共聚-己二酸丁二酯)(PBSA)的物理改性的研究

    Institute of Scientific and Technical Information of China (English)

    王瑞冬; 徐军; 郭宝华

    2012-01-01

    聚(丁二酸丁二酯-共聚-己二酸丁二酯)(PBSA)是一种全生物降解材料,但由于其结晶度较高,无定形区比例较少,导致韧性不足.聚(丁二酸-1,2-丙二酯)(PPSu)是一种非结晶的生物可降解聚酯,在室温下处于无定型态.研究了PPSu对于PBSA的物理改性作用,通过DSC、DMA、POM、SEM测试对PBSA/PPSu的共混体系进行了表征,发现这2种脂肪族聚酯的共混物为部分相容体系,少量PPSu和PBSA相容.随PPSu质量分数的增加,共混体系玻璃化转变温度稍有升高,结晶速率下降.PPSu质量分数达10%时,断面刻蚀的SEM图片显示相分离结构.力学性能测试结果表明,在混入少量PPSu后,PBSA的抗冲击强度得到了较大提升.%Poly (butylene succinate-co-butylene adipate) (PBSA) is a kind of biodegradable material. However, due to its high degree of crystallinity and a low proportion of amorphou region,PBSA has low impact resistance. Poly( 1, 2-propylene succiate) (PPSu) is a kind of amorphous polymer,which can also be fully degraded in environment. In this study, PPSu is blended with PBSA. The miscibility, crystallization kinetics and the mechanical properties of the blends are investigated. Differential scanning caloreroetry, thermomechanical analysis, phase contrast optical microscopy and scanning electron microscopy have been adopted to study the miscibility of the two polymer components. The results show that PBSA and PPSu are miscible partially. When PPSu content is larger than 10 wt% , phase separation is observed in the blends. Increasing the amount of PPSu,the blends have higher glass transition temperature and slower crystallization rate. Compared with PBSA,the impact strength of the blends is greatly improved.

  11. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.

    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 while...... based on similar data from phenyl esters, interpreted as the results of an apparent macrocyclic conformation of the larger diphenyl esters. High-performance size exclusion chromatography (s.e.c.) of diphenyl esters, phenyl esters, aromatic and linear hydrocarbons in tetrahydrofuran, toluene...... and chloroform points to specific phenyl ester-solvent interactions, which obscure a potential s.e.c. conformational analysis of the diphenyl esters....

  12. Synthesis of tertiary benzamides via Pd-catalyzed coupling of arylboronic esters and carbamoyl chlorides

    DEFF Research Database (Denmark)

    Lysén, M.; Kelleher, Susan; Begtrup, M.

    2005-01-01

    Ortho-substituted arylboronic esters are efficiently coupled with carbamoyl chlorides under Pd-catalysis to give tertiary benzamides.......Ortho-substituted arylboronic esters are efficiently coupled with carbamoyl chlorides under Pd-catalysis to give tertiary benzamides....

  13. Influence of alcohol: oil molar ratio on the production of ethyl esters ...

    African Journals Online (AJOL)

    Influence of alcohol: oil molar ratio on the production of ethyl esters by enzymatic transesterification of canola oil. ... cosolvent-free reaction system with ethanol addition in three steps showed great potential for ester production. ... Article Metrics.

  14. A convenient method for lactonization of α-allyl esters using iodine ...

    African Journals Online (AJOL)

    A convenient method for lactonization of α-allyl esters using iodine in dimethyl- sulphoxide. ... KEY WORDS: γ-Butyrolactones, α-Allyl esters, Iodine, Dimethyl sulphoxide. Bull. Chem. Soc. Ethiop. 2014, 28(3) ... Article Metrics. Metrics Loading .

  15. PENGARUH RASIO MOL REAKTAN DAN LAMA SULFONASI TERHADAP KARAKTERISTIK METHYL ESTER SULFONIC (MES DARI METIL ESTER MINYAK SAWIT

    Directory of Open Access Journals (Sweden)

    Sri Hidayati

    2016-04-01

    Full Text Available An experiment of sulfonation process of methyl ester to produce methyl ester sulfonates (MES was caried out using methyl ester palm oil in factorial design and NaHSO as sulfonating agent with variation of ratio mol NaHSO : methyl ester (1:1.25, 1:1.5, 1:1.75 and 1:2 and sulfonation time (3 hour (L1, 4.5 hour (L2 and 6 hour (L3. The result showed that the best sulfonation condition present in 1:1,5 mol ratio and sulfonation time of 4,5 hour. The best characteristic of MES was produced emulsion stability of 68.25%, acid value of 2.57 mg KOH/g, iod value 10.91 g 1od/100 g sample, interfacial tension of 1.806 dyne/cm at MES concentration of 1% (w/w. The optimal salinity occured at concentration of 20.000 ppm which 1FT value of 0.0055 dyne/cm. Heating at a temperature of 800 C for 30 days with the addition of 2 3. Keywords: MES, sulfonation, NaHSO   ABSTRAK Sebuah penelitian tentang proses produksi metil ester sulfonat menggunakan bahan baku metil ester minyak kelapa sawit dilakukan secara faktorial menggunakan NaHSO sebagai agen pensulfonasi dengan variasi rasio mol NaHSO 1:1,25, 1:1,5, 1:1,75 dan 1:2 dan lama sulfonasi.dengan variasi 3; 45; dan 6 jam. Hasil penelitian menunjukkan bahwa kondisi proses sulfonasi terbaik terdapat pada rasio metil ester dan mol reaktan 1:1,5 dan  lama reaksi  4,5 jam dan suhu reaksi lOOoC yang menghasilkan nilai stabilitas emulsi 68,25%, bilangan asam 2,57 mg KOH/g sampel, bilangan iod 10,91 g 1od/100 g sampel. Konsentrasi metil ester sulfonat MES terbaik untuk menghasilkan 1FT terendah adalah 1% (b/b yaitu 1,806 dyne/cm, salinitas optimal terjadi pada 20.000 ppm NaCl dengan nilai 1FT 0,0055 dyne/cm. 0,098 dyne/cm. Kata kunci: MES, proses sulfonasi, NaHSO

  16. Enhancing trimethylolpropane esters synthesis through lipase immobilized on surface hydrophobic modified support and appropriate substrate feeding methods.

    Science.gov (United States)

    Tao, Yifeng; Cui, Caixia; Shen, Huaqing; Liu, Luo; Chen, Biqiang; Tan, Tianwei

    2014-05-10

    Candida sp. 99-125 lipase immobilized on surface hydrophobic modified support and appropriate substrate feeding methods were used to improve the synthesis of tri-substituted trimethylolpropane (TMP) esters, which can be used as raw materials for biodegradable lubricants. The proposed novel production method is environmentally friendly. Lipase was adsorbed on surface hydrophobic silk fibers that were pretreated by amino-modified polydimethylsiloxane. A 5-level-4-factors central composite model, including reaction time, temperature, enzyme amount, and molar ratio of fatty acid to TMP, was designed to evaluate the interaction of process variables in the enzymatic esterification. The water activity was kept constant using a LiCl-saturated salt solution. Under the optimum conditions with 30% enzyme amount and substrates molar ratio 8.4 at 45°C for 47h, the total conversion of caprylic acid is 97.3% and the yield of tri-substituted TMP esters is 95.5%. The surface hydrophobic treatment resulted in less cluster water accumulated on the surface immobilized lipase, which was demonstrated by near-infrared spectra. Consequently, the optimum temperature and water tolerance of immobilized lipase were increased. Two TMP-feeding methods were used to maintain high molar ratio of fatty acid to TMP, and increase the final tri-substituted TMP esters content exceeding 85% (w/w) in reactant.

  17. Assignment of Milk Fat Fatty Acid Propyl Esters by GC-FID Analysis with the Aid of Ag-ion Solid-phase Extraction.

    Science.gov (United States)

    Sasaki, Ryo; Umezawa, Masatoshi; Tsukahara, Satoru; Ishiguro, Takashi; Sato, Shinichi; Watanabe, Yomi

    2015-01-01

    The recovery of short-chain fatty acids (FAs) in milk fat (MF) is improved when the analysis of the FA composition of MF by gas chromatography (GC) is conducted with the propyl or butyl ester derivatives, instead of the methyl esters. However, this approach complicates the detection of minor FAs, such as the minor positional isomers of 16:1, which represent <0.2% of the total content. In addition, the standards of these minor esters are not commercially available. In this study, with the aim to identify minor FAs, the fatty acid propyl esters (FAPEs) of MF were fractionated by Ag-ion solid phase extraction (Ag(+)-SPE) and analyzed by GC using a DB-23 capillary column. FAPEs were successfully fractionated mainly according to the degree of unsaturation by adjusting the elution conditions of the Ag(+)-SPE, and the minor FAPEs were easily determined without the aid of standard compounds. For example, by comparison of the GC profile of the saturated Ag(+)-SPE fraction with that of the original MF, minor FAs, such as iso-, anteiso-, and saturated FAs of 15:0 and 17:0, were expected to be eluted in this order. In addition, 16:1 propyl ester was co-eluted with iso 17:0 propyl ester under the GC conditions used in this study, as confirmed by the detection of the corresponding molecular ions (296 and 312, respectively) by GC-MS. Moreover, 9c,11t-conjugated linoleic acid was found to elute between 18:3 and 20:0. To the best of our knowledge, this is the first report suggesting that the peak observed before that of cis-12:1 corresponds to trans-12:1. In conclusion, Ag(+)-SPE fractionation of FAPEs contributed to the identification of minor FAs in MF without the use of standard compounds.

  18. In vitro pharmacokinetics of anti-psoriatic fumaric acid esters

    NARCIS (Netherlands)

    N.H.R. Litjens (Nicolle); E. van Strijen (Elizabeth); C. van Gulpen (Co); H. Mattie (Herman); J.T. van Dissel (Jaap); H.B. Thio (Bing); P.H. Nibbering (Peter)

    2004-01-01

    textabstractBackground: Psoriasis is a chronic inflammatory skin disease that can be successfully treated with a mixture of fumaric acid esters (FAE) formulated as enteric-coated tablets for oral use. These tablets consist of dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) and its main b

  19. Lipase catalyzed synthesis of aromatic esters of sugar alcohols

    NARCIS (Netherlands)

    Croitoru, R.; Broek, van den L.A.M.; Frissen, A.E.; Davidescu, C.M.; Peter, F.; Boeriu, C.G.

    2011-01-01

    Commercially available lipases (Candida antarctica lipase B, Novozyme 435, Thermomyces lanuginosus lipase, and Lipozyme TL IM), as well as sol-gel immobilized lipases, have been screened for their ability to acylate regioselectively xylitol, sorbitol, and mannitol with a phenolic ester in a binary m

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

    DEFF Research Database (Denmark)

    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...

  1. Preparation of Jojoba Oil Ester Derivatives for Biodiesel Evaluation

    Science.gov (United States)

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

  3. A Convenient Synthesis of Amino Acid Methyl Esters

    Directory of Open Access Journals (Sweden)

    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. Methyl esters (biodiesel) from Pachyrhizus erosus seed oil

    Science.gov (United States)

    The search for additional or alternative feedstocks is one of the major areas of interest regarding biodiesel. In this paper, the fuel properties of Pachyrhizus erosus (commonly known as yam bean or Mexican potato or jicama) seed oil methyl esters were investigated by methods prescribed in biodiesel...

  5. New bis(alkythio) fatty acid methyl esters

    Science.gov (United States)

    The addition reaction of dimethyl disulfide (DMDS) to mono-unsaturated fatty acid methyl esters is well-known for analytical purposes to determine the position of double bonds by mass spectrometry. In this work, the classical iodine-catalyzed reaction is expanded to other dialkyl disulfides (RSSR), ...

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

    NARCIS (Netherlands)

    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

  7. New phenolic esters from the resinous exudate of Haplopappus taeda.

    Science.gov (United States)

    Faini, Francesca; Labbé, Cecilia; Torres, René; Rodilla, Jesús M; Silva, Lucía; Delle Monache, Franco

    2007-12-01

    Two new phenolic esters 9-trans-p-coumaroyloxy-alpha-terpineol (1) and 7-trans-p-coumaroyloxy-taedol (2), both endowed with free radical scavenger activity and cleroda-3,13 (E)-dien-15,18-diol (3) for which a cis stereochemistry at the decalin junction was found, were isolated from the resinous exudate from Haplopappus taeda upper parts.

  8. RAFT Polymerization of Vinyl Esters: Synthesis and Applications

    Directory of Open Access Journals (Sweden)

    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.

  9. Adsorption of diethyl phthalate ester to clay minerals.

    Science.gov (United States)

    Wu, Yanhua; Si, Youbin; Zhou, Dongmei; Gao, Juan

    2015-01-01

    Phthalate esters are a group of plasticizers, which have been widely detected in China's agricultural and industrial soils. In this study, batch adsorption experiments were conducted to investigate the environmental effects on the adsorption of diethyl phthalate ester (DEP) to clay minerals. The results showed that DEP adsorption isotherms were well fitted with the Freundlich model; the interlayer spacing of K(+) saturated montmorillonite (K-mont) was the most important adsorption area for DEP, and di-n-butyl ester (DnBP) was limited to intercalate into the interlayer of K-mont due to the bigger molecular size; there was no significant effect of pH and ionic strength on DEP adsorption to K-mont/Ca-mont, but to Na-mont clay. The adsorption to kaolinite was very limited. Data of X-ray diffraction and FTIR spectra further proved that DEP molecules could intercalate into K-/Ca-mont interlayer, and might interact with clay through H-bonding between carbonyl groups and clay adsorbed water. Coated humic acid on clay surface would enhance DEP adsorption at low concentration, but not at high concentration (eg. Ce>0.26 mM). The calculated adsorption enthalpy (ΔHobs) and adsorption isotherms at varied temperatures showed that DEP could be adsorbed easier as more adsorbed. This study implied that clay type, compound structure, exchangeable cation, soil organic matter and temperature played important roles in phthalate ester's transport in soil.

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

    NARCIS (Netherlands)

    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

  11. Structure and Reactivity of the Cysteine Methyl Ester Radical Cation

    NARCIS (Netherlands)

    Osburn, S.; Steill, J. D.; Oomens, J.; O' Hair, R. A. J.; Van Stipdonk, M.; Ryzhov, V.

    2011-01-01

    The structure and reactivity of the cysteine methyl ester radical cation, CysOMe(center dot+), have been examined in the gas phase using a combination of experiment and density functional theory (DFT) calculations. CysOMe(center dot+) undergoes rapid ion molecule reactions with dimethyl disulfide, a

  12. Presidendiauto jalakäijate teel / Ester Shank

    Index Scriptorium Estoniae

    Šank, Ester, 1956-

    2003-01-01

    Presidendi pressinõunik Ester Shank selgitab, miks president Arnold Rüütel sõitis eskorauto saatel lauluväljakule Andrea Bocelli ja Annely Peebo kontserdile läbi Kadrioru pargi jalakäijate teed mööda

  13. Synthesis and physical properties of pennycress estolides and esters

    Science.gov (United States)

    A new series of pennycress (Thlasphi arvense L.) based free-acid estolides was synthesized by an acid-catalyzed condensation reaction, followed by an esterification reaction to produce the 2-ethylhexyl (2-EH) esters of the initial estolides. The physical properties of the estolides are highly affect...

  14. Synthesis and physical properties of petroselinic based estolide esters

    Science.gov (United States)

    A new series of petroselinic (Coriandrum sativum L.)-based estolide 2-ethylhexyl (2-EH) esters were synthesized, as the capping material varied in length and in degrees of unsaturation, in a perchloric acid catalyzed one-pot process with the esterification process incorporated into an in situ second...

  15. Structure and Reactivity of the Cysteine Methyl Ester Radical Cation

    NARCIS (Netherlands)

    Osburn, S.; Steill, J. D.; Oomens, J.; O' Hair, R. A. J.; Van Stipdonk, M.; Ryzhov, V.

    2011-01-01

    The structure and reactivity of the cysteine methyl ester radical cation, CysOMe(center dot+), have been examined in the gas phase using a combination of experiment and density functional theory (DFT) calculations. CysOMe(center dot+) undergoes rapid ion molecule reactions with dimethyl disulfide,

  16. Ranking of aquatic toxicity of esters modelled by QSAR.

    Science.gov (United States)

    Papa, Ester; Battaini, Francesca; Gramatica, Paola

    2005-02-01

    Alternative methods like predictions based on Quantitative Structure-Activity Relationships (QSARs) are now accepted to fill data gaps and define priority lists for more expensive and time consuming assessments. A heterogeneous data set of 74 esters was studied for their aquatic toxicity, and available experimental toxicity data on algae, Daphnia and fish were used to develop statistically validated QSAR models, obtained using multiple linear regression (MLR) by the OLS (Ordinary Least Squares) method and GA-VSS (Variable Subset Selection by Genetic Algorithms) to predict missing values. An ESter Aquatic Toxicity INdex (ESATIN) was then obtained by combining, by PCA, experimental and predicted toxicity data, from which model outliers and esters highly influential due to their structure had been eliminated. Finally this integrated aquatic toxicity index, defined by the PC1 score, was modelled using only a few theoretical molecular descriptors. This last QSAR model, statistically validated for its predictive power, could be proposed as a preliminary evaluative method for screening/prioritising esters according to their integrated aquatic toxicity, just starting from their molecular structure.

  17. Presidendiauto jalakäijate teel / Ester Shank

    Index Scriptorium Estoniae

    Šank, Ester, 1956-

    2003-01-01

    Presidendi pressinõunik Ester Shank selgitab, miks president Arnold Rüütel sõitis eskorauto saatel lauluväljakule Andrea Bocelli ja Annely Peebo kontserdile läbi Kadrioru pargi jalakäijate teed mööda

  18. Synthesis of fatty acid starch esters in supercritical carbon dioxide

    NARCIS (Netherlands)

    Muljana, Henky; van der Knoop, Sjoerd; Keijzer, Danielle; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2010-01-01

    This manuscript describes an exploratory study on the synthesis of fatty acid/potato starch esters using supercritical carbon dioxide (scCO(2)) as the solvent. The effects of process variables such as pressure (6-25 MPa), temperature (120-150 degrees C) and various basic catalysts and fatty acid der

  19. The Zinc Mediated Condensation of Amino Acid Esters with Imines to b-Lactams

    NARCIS (Netherlands)

    Koten, G. van; Jastrzebski, J.T.B.H.

    1993-01-01

    An experimentally attractive stereoselectie 'one pot' synthesis of beta-lactams is described. This route is based on the zinc mediated condensation of an alpha-amino acid ester with an imine via a zinc ester enolate. Making use of proper substituents in both the amino acid ester and the imine the st

  20. 40 CFR 721.10142 - Oxabicycloalkane carboxylic acid alkanediyl ester (generic).

    Science.gov (United States)

    2010-07-01

    ... alkanediyl ester (generic). 721.10142 Section 721.10142 Protection of Environment ENVIRONMENTAL PROTECTION... ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as oxabicycloalkane carboxylic acid alkanediyl ester (PMN P-06-199)...