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Sample records for radiation polymerizable esters

  1. Controllable synthesis of polymerizable ester and amide prodrugs of acyclovir by enzyme in organic solvent.

    PubMed

    Li, Xia; Wu, Qi; Lv, De-shui; Lin, Xian-fu

    2006-05-15

    A facile control of the acylation position at the primary hydroxyl and amino of acyclovir, respectively, was achieved and five polymerizable acyclovir prodrugs were synthesized. Various reaction conditions were studied in detail. Thus, lipase acrylic resin from Candida antarctica (CAL-B) in pyridine or acetone showed high chemo-selectivity toward the primary hydroxyl of acyclovir. However, lipase PS 'Amano' (PS) in DMSO selectively acylated the amino group. The selectivity of PS could be adjusted by changing reaction solvents. The acyclovir vinyl derivatives obtained would be important monomers used for the preparation of macromolecular nucleoside drugs.

  2. Polymerizable ionic liquid crystals.

    PubMed

    Jazkewitsch, Olga; Ritter, Helmut

    2009-09-17

    Polymerizable vinylimidazolium ionic liquids (ILs) that contain mesogenic coumarin and biphenyl units, respectively, have been synthesized. The N-alkylation of N-vinylimidazole with bromoalkylated mesogenic units 7-(6-bromohexyloxy)coumarin (1) and 4,4'-bis(6-bromohexyloxy)biphenyl (2) was then carried out. The thermal behavior of the obtained ILs 3 and 4 was investigated by differential scanning calorimetry and polarizing optical microscopy. These measurements showed that the attached mesogenic units induce the self-assembly of ILs and, therefore, the occurrence of liquid crystalline phases. Subsequently, the ionic liquid crystals (ILCs) 3 and 4 were polymerized by a free-radical mechanism.

  3. Polymerizable ultraviolet stabilizers for outdoor use

    NASA Technical Reports Server (NTRS)

    Vogl, O.

    1982-01-01

    Polymeric materials that are stable enough to use outdoors without changes in excess of 20 years are investigated. Ultraviolet stabilizers or plastic materials were synthesized, polymerizable ultraviolet stabilizers, particularly of the 2(2-hydroxyphenyl)2H-benzotriazole family were prepared their polymerization, copolymerization and grafting onto other polymers were demonstrated, and ultraviolet stabilizing systems were devised. These materials were evaluated from the photophysical point of view.

  4. Cationically polymerizable monomers derived from renewable sources

    SciTech Connect

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  5. Cationically polymerizable monomers derived from renewable sources

    SciTech Connect

    Crivello, J.V.

    1991-10-01

    The objective of this project is to make use of products obtained from renewable plant sources as monomers for the direct production of polymers which can be used for a wide range of plastic applications. In this report is described progress in the synthesis and polymerization of cationically polymerizable monomers and oligomers derived from botanical oils, terpenes, natural rubber, and lignin. Nine different botanical oils were obtained from various sources, characterized and then epoxidized. Their photopolymerization was carried out using cationic photoinitiators and the mechanical properties of the resulting polymers characterized. Preliminary biodegradation studies are being conducted on the photopolymerized films from several of these oils. Limonene was cationically polymerized to give dimers and the dimers epoxidized to yield highly reactive monomers suitable for coatings, inks and adhesives. The direct phase transfer epoxidation of squalene and natural rubber was carried out. The modified rubbers undergo facile photocrosslinking in the presence of onium salts to give crosslinked elastomers. 12 refs., 3 figs., 10 tabs.

  6. Stability of a salicylate-based poly(anhydride-ester) to electron beam and gamma radiation

    PubMed Central

    Rosario-Meléndez, Roselin; Lavelle, Linda; Bodnar, Stanko; Halperin, Frederick; Harper, Ike; Griffin, Jeremy; Uhrich, Kathryn E.

    2011-01-01

    The effect of electron beam and gamma radiation on the physicochemical properties of a salicylate-based poly(anhydride-ester) was studied by exposing polymers to 0 (control), 25 and 50 kGy. After radiation exposure, salicylic acid release in vitro was monitored to assess any changes in drug release profiles. Molecular weight, glass transition temperature and decomposition temperature were evaluated for polymer chain scission and/or crosslinking as well as changes in thermal properties. Proton nuclear magnetic resonance and infrared spectroscopies were also used to determine polymer degradation and/or chain scission. In vitro cell studies were performed to identify cytocompatibility following radiation exposure. These studies demonstrate that the physicochemical properties of the polymer are not substantially affected by exposure to electron beam and gamma radiation. PMID:21909173

  7. Polymerizable 2(2-hydroxynaphthyl)2H-benzotriazole compounds

    DOEpatents

    Gomez, Peter M.; Neidlinger, Hermann H.

    1991-01-01

    Benzotriazole compounds having the formula: ##STR1## wherein R.sub.1 is H, Cl, or OCH.sub.3 ; R.sub.2 is a hydroxynaphthyl group; and R.sub.3 is a vinyl unsaturated polymerizable group. Homopolymers or copolymers thereof are effective as UV light stabilizers and absorbers.

  8. Polymerizable 2(2-hydroxynaphthyl)2H-benzotriazole compounds

    DOEpatents

    Gomez, P.M.; Neidlinger, H.H.

    1991-07-16

    Benzotriazole compounds having the formula: ##STR1## wherein R.sub.1 is H, Cl, or OCH.sub.3 ; R.sub.2 is a hydroxynaphthyl group; and R.sub.3 is a vinyl unsaturated polymerizable group. Homopolymers or copolymers thereof are effective as UV light stabilizers and absorbers.

  9. Protective effects of caffeic acid phenethyl ester against acute radiation-induced hepatic injury in rats.

    PubMed

    Chu, JianJun; Zhang, Xiaojun; Jin, Liugen; Chen, Junliang; Du, Bin; Pang, Qingfeng

    2015-03-01

    Caffeic acid phenyl ester (CAPE) is a potent anti-inflammatory agent and it can eliminate the free radicals. The current study was intended to evaluate the protective effect of CAPE against the acute radiation-induced liver damage in rats. Male Sprague-Dawley rats were intraperitoneally administered with CAPE (30 mg/kg) for 3 consecutive days before exposing them to a single dose of 30 Gy of β-ray irradiation to upper abdomen. We found that pretreatment with CAPE significantly decreased the serum levels of alanine aminotransferase and aspartate aminotransferase and increased the activity of superoxide dismutase and glutathione. Histological evaluation further confirmed the protection of CAPE against radiation-induced hepatotoxicity. TUNEL assay showed that CAPE pretreatment inhibited hepatocyte apoptosis. Moreover, CAPE inhibited the nuclear transport of NF-κB p65 subunit, decreased the level of tumor necrosis factor-α, nitric oxide and inducible nitric oxide synthase. Taken together, these results suggest that pretreatment with CAPE offers protection against radiation-induced hepatic injury.

  10. Adsorption and adsolubilization of polymerizable surfactants on aluminum oxide.

    PubMed

    Attaphong, Chodchanok; Asnachinda, Emma; Charoensaeng, Ampira; Sabatini, David A; Khaodhiar, Sutha

    2010-04-01

    Surfactant-based adsorption processes have been widely investigated for environmental applications. A major problem facing surfactant-modified adsorbents is surfactant loss from the adsorbent due to loss of monomers from solution and subsequent surfactant desorption. For this study, a bilayer of anionic polymerizable surfactant (Hitenol BC 05, Hitenol BC 10 and Hitenol BC 20) and non-polymerizable surfactant (Hitenol N 08) was adsorbed onto alumina. The results of adsorption studies showed that as the number of ethylene oxide (EO) groups of the surfactants increased, the area per molecule increased and the maximum adsorption decreased. The lowest maximum adsorption onto alumina was for Hitenol BC 20 (20 EO groups) corresponding to 0.08 mmol/g or 0.34 molecule/nm(2) while the highest level of adsorption was 0.30 mmol/g or 1.28 molecule/nm(2) for Hitenol BC 05 (5 EO groups). This variation in adsorption was attributed to the increased bulkiness of the head group with increasing number of EO groups. Relative to the adsolubilization capacity of organic solutes, ethylcyclohexane adsolubilizes more than styrene. Styrene and ethylcyclohexane adsolubilization were both independent of the number of EO groups of the surfactant. For surfactant desorption studies, the polymerization of polymerizable surfactants increased the stability of surfactants adsorbed onto the alumina surface and reduced surfactant desorption from the alumina surface. These results provide useful information on surfactant-based surface modification to enhance contaminant remediation and industrial applications.

  11. Binding of europium complex to polymerizable macrocyclic molecules and its optical properties

    NASA Astrophysics Data System (ADS)

    Hidayat, Rahmat; Sugihara, Okihiro; Tsuchimori, Masaaki; Kagami, Manabu; Nishikubo, Tadatomi; Kaino, Toshikuni

    2007-07-01

    Study on the incorporation of trivalent europium (Eu3+) complex into polymerizable macrocylic molecules, namely calixarene and calixresorcinarene derivatives, has been carried out. Broadening of hypersensitive luminescence peak was observed in solution and polymer containing a compound of europium complex and calixresorcinarene monomer, which is ascribed to ligand field splitting due to anisotropic local field at the Eu3+ ion site. From 1H NMR spectroscopy, it is found that the chemical shift originated from the moiety at the upper rim of calixresorcinarene is remarkably downfield shifted. Pseudocontact shift analysis suggests that binding between Eu3+ ion and calixresorcinarene monomer is formed at the Eu3+ second coordination sphere. These experimental results show that the binding does not alter nephelauxetic effect of the Eu3+ first coordination shell, but only slightly change coordination structure and symmetry. Nevertheless, the binding results in longer luminescence lifetime in comparison to the case of pure europium complex indicating significant reduction of non-radiative decay.

  12. Preparation of polymeric nanoparticles using a new polymerizable surfactant

    NASA Astrophysics Data System (ADS)

    Bunio, Paulina; Zielińska, Katarzyna; Chlebicki, Jan; Wilk, Kazimiera

    2011-04-01

    A novel polymerizable surfactant (so-called surfmer) was synthesized and characterized according to its structure, surface activity and polymerization ability. Polymeric micelles (size of 6 and 130 nm) appeared in the polyreaction initiated by free radicals from VA-044. In the presence of the monomer (i.e., methyl methacrylate) microemulsion systems were formed that in turn were transformed into latex entities (size — 40 nm). Additionally, an emulsion polymerization was performed with the use of n-hexadecane as an oil phase resulting in the production of nanocapsules (size in the range — 165-220 nm). The shape and morphologies of the nanoobjects were confirmed using Atomic Force Microscopy (AFM).

  13. Cationically polymerizable monomers derived from renewable sources. Annual performance report

    SciTech Connect

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year`s research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  14. Incorporation of polymerizable surfactants in hydroxyethyl methacrylate lenses for improving wettability and lubricity.

    PubMed

    Bengani, Lokendrakumar C; Scheiffele, Gary W; Chauhan, Anuj

    2015-05-01

    Dryness and discomfort are the main reasons for dropouts in contact lens wearers. Incorporating surfactants in lens formulations could improve wettability and lubricity, which can improve comfort. We have focused on incorporating polymerizable surfactants in hydroxyethyl methacrylate lenses to improve comfort, while minimizing the potential for surfactant release into the tears. The surfactants were added to the polymerization mixture, followed by UV curing and extraction of leachables in hot water. Wettability and lubricity were characterized by measuring the contact angle and coefficient of friction. Lenses were also characterized by measuring transmittance, loss and storage moduli and ion permeability. Incorporation of surfactants significantly reduced contact angle from 90° for p-HEMA gels to about 10° for 2.43% (w/w) surfactant loading in hydrated gel. The coefficient of friction also decreased from about 0.16 for HEMA gels to 0.05 for the gels with 2.43% surfactant loading. There was a good correlation between the contact angle and coefficient of friction suggesting that both effects can be related to the stretching of the surfactant tails near the surface into the aqueous phase. The water content was also correlated with the surfactant loading but the contact angle was more sensitive suggesting that the observed improvements in wettability and lubricity arise from the protrusion of the surfactant tails in into the liquid, and not purely from the increase in the water content. The gels were clear and certain compositions also have the capability to block UVC and UVB radiation. The results suggest that incorporation of polymerizable surfactants could be useful in improving surface properties without significantly impacting any bulk property.

  15. Structure of Lipid Tubules Formed from a Polymerizable Lecithin

    PubMed Central

    Yager, Paul; Schoen, Paul E.; Davies, Carol; Price, Ronald; Singh, Alok

    1985-01-01

    We have studied tubules formed from a polymerizable lipid in aqueous dispersion using freeze-fracture replication and transmission electron microscopy. The polymerizable diacetylenic lecithin 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine converts from liposomes to hollow cylinders, which we call tubules, on cooling through its chain melting phase transition temperature. These tubules differ substantially from cochleate cylinders formed by phosphatidylserines on binding of calcium. The tubules have diameters that range from 0.3 to 1 μm and lengths of up to hundreds of micrometers depending on conditions of formation. The thickness of the walls varies from as few as two bilayers to tens of bilayers in some longer tubules. Their surfaces may be either smooth, gently rippled, or with spiral steps depending on sample preparation conditions, including whether the lipids have been polymerized. The spiral steps may reflect the growth of the tubules by rolling up of flattened liposomes. ImagesFIGURE 1FIGURE 2FIGURE 3FIGURE 4FIGURE 5FIGURE 6FIGURE 7FIGURE 8FIGURE 9 PMID:19431600

  16. Self-organization of polymerizable bolaamphiphiles bearing diacetylene mesogenic group.

    PubMed

    Yin, Shouchun; Song, Bo; Liu, Guanqing; Wang, Zhiqiang; Zhang, Xi

    2007-05-22

    We report herein the synthesis of a series of polymerizable bolaamphiphiles containing a diacetylene group and mesogenic unit and their self-organization behaviors in bulk and at interface. The polymerizable bolaamphiphiles are noted as DPDA-n, where n refers to the spacer length of alkyl chain. DPDA-10 with suitable spacer length can self-organize into stable cylindrical micellar nanostructures, and these nanostructures have preferred orientation regionally when adsorbed at the mica/water interface. It is confirmed that the micellar nanostructure of DPDA-10 can be polymerized both in the bulk solution and in the film by UV irradiation. The emission property of DPDA-10 after UV irradiation has been significantly enhanced in comparison to that before polymerization, which may be due to the extension of the conjugated system arising from the transformation of the diacetylene group into polydiacetylene upon polymerization. In addition, the self-organization of DPDA-n is dependent on the spacer length. DPDA-7 with a short spacer length forms an irregular flat sheet structure with many defects; DPDA-15 with a long spacer length forms rodlike micellar structures. Thus, this work may provide a new approach for designing and fabricating organic functional nanostructured materials.

  17. The effects of Nigella sativa oil, thymoquinone, propolis, and caffeic acid phenethyl ester on radiation-induced cataract.

    PubMed

    Demir, Elif; Taysi, Seyithan; Al, Behcet; Demir, Tuncer; Okumus, Seydi; Saygili, Oguzhan; Saricicek, Edibe; Dirier, Ahmet; Akan, Muslum; Tarakcioglu, Mehmet; Bagci, Cahit

    2016-12-01

    The aim of this study was to investigate the antioxidant and radioprotective effects of propolis, caffeic acid phenethyl ester (CAPE), Nigella sativa oil (NSO), and thymoquinone (TQ) against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats with single dose of 5-Gy cobalt-60 gamma rays. A total of 74 Sprague-Dawley rats were divided into 8 groups to test the radioprotective effectiveness of Nigella sativa oil, thymoquine, propolis, or caffeic acid phenethyl ester administered by either orogastric tube or intraperitoneal injection. Appropriate control groups were also studied. Chylack's cataract classification was used in the study. At the end of the tenth day, cataracts developed in 80 % of the rats in the radiotherapy group. After irradiation, cataract rate dropped to 20 % in NSO, 30 % in propolis, 40 % in CAPE, and 50 % in TQ groups and was limited to grade 1 and grade 2. Cataract formation was observed the least in NSO group and the most in TQ group. In the irradiated (IR) group, superoxide dismutase activity was lower, while glutathione peroxidase and xanthine oxidase activities and malondialdehyde level were higher compared with the other groups. Total superoxide scavenger activity and nonenzymatic superoxide scavenger activity were not statistically significant in IR group compared with the other groups. The findings obtained in the study might suggest that propolis, CAPE, NSO, and TQ could prevent cataractogenesis in ionizing radiation-induced cataracts in the lenses of rats, wherein propolis and NSO were found to be more potent.

  18. Polymerizable ionic liquid with state of the art transport properties.

    PubMed

    Jeremias, Sebastian; Kunze, Miriam; Passerini, Stefano; Schönhoff, Monika

    2013-09-12

    The physicochemical properties of diallyldimethylammonium-bis(trifluoromethanesulfonyl)imide (DADMATFSI) and its binary mixture with LiTFSI are presented herein, also showing this novel compound as a polymerizable room temperature ionic liquid with excellent transport properties for Li(+) ions. In particular, results of pulsed field gradient (PFG)-NMR diffusion experiments and impedance measurements show that DADMATFSI exhibits state of the art properties of ionic liquids. Similar ionic diffusion coefficients and a similarly high conductivity as seen in the benchmark compound N-butyl-N-methylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (PYR14TFSI) are observed. In accordance, the Li transference number in the binary mixture matches the trend seen for PYR14TFSI-LiTFSI mixtures. In addition to these impressive properties as ionic liquid, DADMATFSI was polymerized by UV treatment. The polymerization is demonstrated and the ion conducting properties of the resulting gel polymer electrolyte are investigated, showing that DADMATFSI can be transformed into an ionogel and may have applications where polymerization is desirable.

  19. Fixed Junction Photovoltaic Devices Based On Polymerizable Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Limanek, Austin; Leger, Janelle, , Dr.

    Recently, polymer-based photovoltaic devices (PPVs) have received significant attention as a possible affordable, large area and flexible solar energy technology. In particular, research on chemically fixed p-i-n junctions in polymer photovoltaic devices has shown promising results. These devices are composed of ionic monomers in a polymer matrix sandwiched between two electrodes. When a potential is applied, the ionic monomers migrate towards their corresponding electrodes, enabling electrochemical doping of the polymer. This leads to the formation of bonds between the polymer and ionic monomers, resulting in the formation of a chemically fixed p-i-n junction. However, early devices suffered from long charging times and low overall response. This has been attributed to the low phase compatibility between the ionic monomers and the polymer. It has been shown for light-emitting electrochemical cells, replacing the ionic monomers with polymerizable ionic liquids (PILs) mitigates these challenges. We will present the use of PILs as the dopant in fixed junction PPV devices. Preliminary devices demonstrate significantly improved performance, decreased charging times, and high open circuit voltages. This research supported by the National Science Foundation DMR-1057209.

  20. Radiation sensitivity and EPR dosimetric potential of gallic acid and its esters

    NASA Astrophysics Data System (ADS)

    Tuner, Hasan; Oktay Bal, M.; Polat, Mustafa

    2015-02-01

    In the preset work the radiation sensitivities of Gallic Acid anhydrous and monohydrate, Octyl, Lauryl, and Ethyl Gallate (GA, GAm, OG, LG, and EG) were investigated in the intermediate (0.5-20 kGy) and low radiation (<10 Gy) dose range using Electron Paramagnetic Resonance (EPR) spectroscopy. While OG, LG, and EG are presented a singlet EPR spectra, their radiation sensitivity found to be very different in the intermediate dose range. At low radiation dose range (<10 Gy) only LG is found to be present a signal that easily distinguished from the noise signals. The intermediate and low dose range radiation sensitivities are compared using well known EPR dosimeter alanine. The radiation yields (G) of the interested material were found to be 1.34×10-2, 1.48×10-2, 4.14×10-2, and 6.03×10-2, 9.44×10-2 for EG, GA, GAm, OG, and LG, respectively at the intermediate dose range. It is found that the simple EPR spectra and the noticeable EPR signal of LG make it a promising dosimetric material to be used below 10 Gy of radiation dose.

  1. Enhanced antioxidant effect of caffeic acid phenethyl ester and Trolox in combination against radiation induced-oxidative stress.

    PubMed

    Bai, Hua; Liu, Rui; Chen, Hong-Li; Zhang, Wei; Wang, Xin; Zhang, Xiao-Di; Li, Wen-Li; Hai, Chun-Xu

    2014-01-25

    Combinations of antioxidants are believed to be more effective than single antioxidant because when antioxidants are combined they support each other synergistically to create a magnified effect. Discovering the enhancer effects or synergies between bioactive components is valuable for resisting oxidative stress and improving health benefits. The aim of this study was to investigate a possible cooperation of natural antioxidant caffeic acid phenethyl ester (CAPE) with synthetic antioxidant Trolox in the model systems of chemical generation of free radicals, lipid peroxidation of microsomes and radiation-induced oxidative injury in L929 cells. Based on the intermolecular interaction between CAPE and Trolox, the present study shows a synergistic effect of CAPE and Trolox in combination on elimination of three different free radicals and inhibition of lipid peroxidation initiated by three different systems. CAPE and Trolox added simultaneously to the L929 cells exerted an enhanced preventive effect on the oxidative injury induced by radiation through decreasing ROS generation, protecting plasma membrane and increasing the ratios of reduced glutathione/oxidized glutathione and the expression of key antioxidant enzymes mediated by nuclear factor erythroid 2 p45-related factor 2 (Nrf2). Our results showed for the first time that administration of CAPE and Trolox in combination may exert synergistic antioxidant effects, and further indicate that CAPE and Trolox combination functions mainly through scavenging ROS directly, inhibiting lipid peroxidation and promoting redox cycle of GSH mediated by Nrf2-regulated glutathione peroxidase and glutathione reductase expression. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Amino-Acid-Based Polymerizable Surfactants for the Synthesis of Chiral Nanoparticles.

    PubMed

    Preiss, Laura C; Wagner, Manfred; Mastai, Yitzhak; Landfester, Katharina; Muñoz-Espí, Rafael

    2016-09-01

    Amino-acid-based chiral surfactants with polymerizable moieties are synthesized, and a versatile approach to prepare particles thereof with a chiral surface functionality is presented. As an example of an application, the synthesized particles are tested for their ability as nucleating agents in the enantioselective crystallization of amino acid conglomerate systems, taking rac-asparagine as a model system. Particles resulting from chiral surfactants with different tail groups are compared and the results demonstrate that only the chiral nanoparticles made of the polymerizable surfactant are able to act efficiently as nucleation agent in enantioselective crystallization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Method of analysis of polymerizable monomeric species in a complex mixture

    DOEpatents

    Hermes, Robert E

    2014-03-18

    Method of selective quantitation of a polymerizable monomeric species in a well spacer fluid, said method comprising the steps of adding at least one solvent having a refractive index of less than about 1.33 to a sample of the complex mixture to produce a solvent phase, and measuring the refractive index of the solvent phase.

  4. Caffeic acid phenethyl ester preferentially sensitizes CT26 colorectal adenocarcinoma to ionizing radiation without affecting bone marrow radioresponse

    SciTech Connect

    Chen, Y.-J.; Liao, H.-F.; Tsai, T.-H.; Wang, S.-Y.; Shiao, M.-S. . E-mail: msshiao@vghtpe.gov.tw

    2005-11-15

    Purpose: Caffeic acid phenethyl ester (CAPE), a component of propolis, was reported capable of depleting glutathione (GSH). We subsequently examined the radiosensitizing effect of CAPE and its toxicity. Methods and Materials: The effects of CAPE on GSH level, GSH metabolism enzyme activities, NF-{kappa}B activity, and radiosensitivity in mouse CT26 colorectal adenocarcinoma cells were determined. BALB/c mouse with CT26 cells implantation was used as a syngeneic in vivo model for evaluation of treatment and toxicity end points. Results: CAPE entered CT26 cells rapidly and depleted intracellular GSH in CT26 cells, but not in bone marrow cells. Pretreatment with nontoxic doses of CAPE significantly enhanced cell killing by ionizing radiation (IR) with sensitizer enhancement ratios up to 2.2. Pretreatment of CT26 cells with N-acetyl-L-cysteine reversed the GSH depletion activity and partially blocked the radiosensitizing effect of CAPE. CAPE treatment in CT26 cells increased glutathione peroxidase, decreased glutathione reductase, and did not affect glutathione S-transferase or {gamma}-glutamyl transpeptidase activity. Radiation activated NF-{kappa}B was reversed by CAPE pretreatment. In vivo study revealed that pretreatment with CAPE before IR resulted in greater inhibition of tumor growth and prolongation of survival in comparison with IR alone. Pretreatment with CAPE neither affected body weights nor produced hepatic, renal, or hematopoietic toxicity. Conclusions: CAPE sensitizes CT26 colorectal adenocarcinoma to IR, which may be via depleting GSH and inhibiting NF-{kappa}B activity, without toxicity to bone marrow, liver, and kidney.

  5. Aligned nanostructured polymers by magnetic-field-directed self-assembly of a polymerizable lyotropic mesophase.

    PubMed

    Tousley, Marissa E; Feng, Xunda; Elimelech, Menachem; Osuji, Chinedum O

    2014-11-26

    Magnetic-field-directed assembly of lyotropic surfactant mesophases provides a scalable approach for the fabrication of aligned nanoporous polymers by templated polymerization. We develop and characterize a lyotropic liquid crystalline system containing hexagonally packed cylindrical micelles of a polymerizable surfactant in a polymerizable solvent. The system exhibits negative magnetic anisotropy, resulting in the degenerate alignment of cylindrical micelles perpendicular to the magnetic field. Sample rotation during field alignment is used to effectively break this degeneracy and enable the production of uniformly well-aligned mesophases. High-fidelity retentions of the hexagonal structure and alignment were successfully achieved in polymer films produced upon UV exposure of the reactive system. The success of this effort provides a route for the fabrication of aligned nanoporous membranes suitable for highly selective separations, sensing, and templated nanomaterial synthesis.

  6. Characterization of the phase behaviour of a novel polymerizable lyotropic ionic liquid crystal.

    PubMed

    Goujon, Nicolas; Forsyth, Maria; Dumée, Ludovic F; Bryant, Gary; Byrne, Nolene

    2015-09-21

    The development of new polymerizable lyotropic liquid crystals (LLCs) utilizing charged amphiphilic molecules such as those based on long chain imidazolium compounds, is a relatively new design direction for producing robust membranes with controllable nano-structures. Here we have developed a novel polymerizable ionic liquid based LLC, 1-hexadecyl-3-methylimidazolium acrylate (C16mimAcr), where the acrylate anion acts as the polymerizable moiety. The phase behaviour of the C16mimAcr upon the addition of water was characterized using small and wide angle X-ray scatterings, differential scanning calorimetry and polarized optical microscopy. We compare the phase behaviour of this new polymerizable LLC to that of the well known LLC chloride analogue, 1-hexadecyl-3-methylimidazolium chloride (C16mimCl). We find that the C16mimAcr system has a more complex phase behaviour compared to the C16mimCl system. Additional lyotropic liquid crystalline mesophases such as hexagonal phase (H1) and discontinuous cubic phase (I1) are observed at 20 °C for the acrylate system at 50 and 65 wt% water respectively. The appearance of the hexagonal phase (H1) and discontinuous cubic phase (I1) for the acrylate system is likely due to the strong hydrating nature of the acrylate anion, which increases the head group area. The formation of these additional mesophases seen for the acrylate system, especially the hexagonal phase (H1), coupled with the polymerization functionality offers great potential in the design of advanced membrane materials with selective and anisotropic transport properties.

  7. Synthesis of Polymerizable Cyclodextrin Derivatives for Use in Adhesion-Promoting Monomer Formulations

    PubMed Central

    Bowen, Rafael L.; Carey, Clifton M.; Flynn, Kathleen M.; Guttman, Charles M.

    2009-01-01

    The synthesis of the cyclodextrin derivatives reported herein was assisted by extensive literature research together with structure-property relationships derived from three-dimensional molecular modeling. These studies led to the hypothesis that many of the 21 hydroxyl groups on beta-cyclodextrin molecules could be derivatized to form a closely related family of analogous chemical compounds containing both polymerizable groups and hydrophilic ionizable ligand (substrate-binding) groups, each attached via hydrolytically-stable ether-linkages. The vinylbenzylether polymerizable groups should readily homopolymerize and also copolymerize with methacrylates. This could be highly useful for dental applications because substantially all contemporary dental resins and composites are based on methacrylate monomers. Due to hydrophilic ligands and residual hydroxyl groups, these cyclodextrin derivatives should penetrate hydrated layers of dentin and enamel to interact with collagen and tooth mineral. Analyses indicated that the diverse reaction products resulting from the method of synthesis reported herein should comprise a family of copolymerizable molecules that collectively contain about 30 different combinations of vinylbenzyl and hexanoate groups on the various molecules, with up to approximately seven of such groups combined on some of the molecules. Although the hypothesis was supported, and adhesive bonding to dentin is expected to be significantly improved by the use of these polymerizable cyclodextrin derivatives, other efforts are planned for improved synthetic methods to ensure that each of the reaction-product molecules will contain at least one copolymerizable moiety. The long-term objective is to enable stronger and more durable attachments of densely cross-linked polymers to hydrated hydrophilic substrates. Capabilities for bonding of hydrolytically stable polymers to dental and perhaps other hydrous biological tissues could provide widespread benefits. PMID

  8. Langmuir-Blodgett films of fluorinated glycolipids and polymerizable lipids and their phase separating behavior.

    PubMed

    Scheibe, Patrick; Schoenhentz, Jerome; Platen, Tobias; Hoffmann-Röder, Anja; Zentel, Rudolf

    2010-12-07

    This paper describes the phase separating behavior of Langmuir monolayers from mixtures of different lipids that (i) either carry already a glycopeptide recognition site or can be easily modified to carry one and (ii) polymerizable lipids. To ensure demixing during compression, we used fluorinated lipids for the biological headgroups and hydrocarbon based lipids as polymerizable lipids. As a representative for a lipid monomer, which can be polymerized in the hydrophilic headgroup, a methacrylic monomer was used. As a monomer, which can be polymerized in the hydrophobic tail, a lipid with a diacetylene unit was used (pentacosadiynoic acid, PDA). The fluorinated lipids were on the one hand a perfluorinated lipid with three chains and on the other hand a partially fluorinated lipid with a T(N)-antigen headgroup. The macroscopic phase separation was observed by Brewster angle microscopy, whereas the phase separation on the nanoscale level was observed by atomic force microscopy. It turned out that all lipid mixtures showed (at least) a partial miscibility of the hydrocarbon compounds in the fluorinated compounds. This is positive for pattern formation, as it allows the formation of small demixed 2D patterned structures during crystallization from the homogeneous phase. For miscibility especially a liquid analogue phase proved to be advantageous. As lipid 3 with three fluorinated lipid chains (very stable monolayer) is miscible with the polymerizable lipids 1 and 2, it was mostly used for further investigations. For all three lipid mixtures, a phase separation on both the micrometer and the nanometer level was observed. The size of the crystalline domains could be controlled not only by varying the surface pressure but also by varying the molar composition of the mixtures. Furthermore, we showed that the binary mixture can be stabilized via UV polymerization. After polymerization and subsequent expansion of the barriers, the locked-in polymerized structures are stable

  9. Recent advances in gemini surfactants: oleic Acid-based gemini surfactants and polymerizable gemini surfactants.

    PubMed

    Sakai, Kenichi; Sakai, Hideki; Abe, Masahiko

    2011-01-01

    Gemini surfactants recently developed by our research group are introduced from the standpoints of their syntheses, aqueous solution properties, and potential applications. Two series of gemini surfactants are introduced in this short review, the first of which is the oleic acid-based gemini surfactants, and the second is the polymerizable gemini surfactants. These gemini surfactants have been developed not only as environmentally friendly materials (the use of gemini surfactants enables the reduction of the total consumption of surfactants in chemical products owing to their excellent adsorption and micellization capabilities at low concentrations) but also as functional organic materials.

  10. Microhardness of light- and dual-polymerizable luting resins polymerized through 7.5-mm-thick endocrowns.

    PubMed

    Gregor, Ladislav; Bouillaguet, Serge; Onisor, Ioana; Ardu, Stefano; Krejci, Ivo; Rocca, Giovanni Tommaso

    2014-10-01

    The complete polymerization of luting resins through thick indirect restorations is still questioned. The purpose of this study was to evaluate the degree of polymerization of light- and dual-polymerizable luting resins under thick indirect composite resin and ceramic endocrowns by means of Vickers microhardness measurements. The Vickers microhardness measurements of a light-polymerizable microhybrid composite resin and a dual-polymerizable luting cement directly polymerized in a natural tooth mold for 40 seconds with a high-power light-emitting diode lamp (control) were compared with measurements after indirect irradiation through 7.5-mm-thick composite resin and ceramic endocrowns for 3 × 90 seconds. A test-to-control microhardness values ratio of 0.80 at a depth of 0.5 mm below the surface was assumed as the criterion for adequate conversion. For the Vickers microhardness measurements of a dual-polymerizable luting cement, no differences (P>.05) were found between Vickers microhardness control values and values reported after polymerization through composite resin and ceramic endocrowns. For The Vickers microhardness measurements (±SD) of a light-polymerizable microhybrid composite resin, control values were significantly (P<.05) higher (111 ±3.3) than those reported after polymerization through composite resin (100.5 ±3.8) and ceramic (99.7 ±2.3) endocrowns. However, the hardness values of The Vickers microhardness measurements of a light-polymerizable microhybrid composite resin polymerized through the endocrowns were approximately 10% to 12% lower than those of the control values. Two-way ANOVA showed the influence of the luting material on the Vickers microhardness values (P<.05). The effect of endocrown material was not significant (P>.05). Under the conditions of this in vitro study, Vickers microhardness values of the dual-polymerizable resin cement and the light-polymerizable restorative composite resin irradiated for 3 × 90 seconds with a high

  11. Surface Enrichment by Conventional and Polymerizable Sulfated Nonylphenol Ethoxylate Emulsifiers in Water-Based Pressure-Sensitive Adhesive

    Treesearch

    Jilin Zhang; Yuxi Zhao; Matthew R. Dubay; Steven J. Severtson; Larry E. Gwin; Carl J. Houtman

    2013-01-01

    Comparisons of properties are made for pressure-sensitive adhesives (PSAs) generated via emulsion polymerization using both conventional and reactive emulsifiers. The emulsifiers are ammonium salts of sulfated nonylphenol ethoxylates with similar chemical structures and hydrophilic−lipophilic balances. The polymerizable surfactant possesses a reactive double...

  12. Synthesis of La-Co Substituted M-type Calcium Hexaferrite by Polymerizable Complex Method

    NASA Astrophysics Data System (ADS)

    Kikuchi, T.; Nakamura, T.; Yamasaki, T.; Nakanishi, M.; Fujii, T.; Takada, J.; Ikeda, Y.

    2011-10-01

    Synthesis of La-Co substituted M-type Calcium hexaferrite was studied. Samples were prepared by polymerizable complex method. High purity reagent of strontium carbonate, iron (III) nitrate ennnahydrate, cobalt (II) nitrate hexahydrate and lanthanum oxide were used as starting materials. Prepared aqueous solution was heated for dehydration and gelling. Thermal pyrolysis was carried out by heating the gel. The obtained precursor powders were ground with an alumina mortar and compacted by uniaxial pressing into disk specimens and then heated at temperature range between 1173 K and 1573 K in air. Phase identification and determination of lattice parameters were carried out by powder X-ray diffraction (XRD). Scanning Electron Microscope (SEM) was utilized to investigate the microstructure of the polycrystalline ferrites. Magnetic properties were discussed by magnetization measurements by measuring of M-H curve with vibrating sample magnetometer (VSM). Single-phase of M-type hexaferrite was obtained at lower temperature relative to by conventional synthesis.

  13. Janus emulsions formed with a polymerizable monomer, silicone oil, and Tween 80 aqueous solution.

    PubMed

    Ge, Lingling; Lu, Shuhui; Guo, Rong

    2014-06-01

    Janus emulsions of a polymerizable monomer tripropyleneglycol diacrylate (TP) combined with silicone oil (SO) as inner oil phases and Tween 80 aqueous solution as continuous phase are prepared in a one-step high energy mixing process. The dependence of droplet topology on the concentration of surfactant, TP/SO ratio, and the stirring speed during emulsification is investigated. The result shows that the volume ratio of two oils within an individual droplet changes correspondingly to the total composition of emulsion. Increasing the speed of stirring results in a significant reduction in the droplet size, i.e. a five times increase in the stirring speed produces a droplet size reduction from hundreds to a few microns. What is more important, the topology of Janus drops remains similar for the different preparations. These fundamental investigations illustrate the potential for future Janus particle synthesis in batch scale with a controllable particle topology.

  14. Synthesis of a polymerizable fluorosurfactant for the construction of stable nanostructured proton-conducting membranes.

    PubMed

    Wadekar, Mohan N; Jager, Wolter F; Sudhölter, Ernst J R; Picken, Stephen J

    2010-10-15

    The synthesis of the polymerizable fluorinated surfactant sodium 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-2-(4-vinylphenyl)ethoxy)ethanesulfonate (1) and a number of related fluorocarbon compounds is described. Compound 1 is synthesized using a copper-mediated cross-coupling reaction of 4-bromobenzaldehyde and sodium 5-iodooctafluoro-3-oxapentanesulfonate. The resulting benzaldehyde is converted to a styrene unit using a Wittig reaction with methyltriphenylphosphonium bromide in acetonitrile, using DBU as a base. This strategy for converting an iodo-functionalized fluorosurfactant to a styrene-containing fluorosurfactant is highly efficient because both reactions are performed in polar solvents and are compatible with the sulfonate moiety. In addition, the copper-mediated cross-coupling reaction is most efficient with electron-poor aryl bromides like 4-bromobenzaldehyde. We wish to employ 1 for the construction of nanostructured membranes by polymerization of 1 in a microemulsion or in lyotropic liquid crystalline phases.

  15. Caffeic Acid Phenethyl Ester Increases Radiosensitivity of Estrogen Receptor-Positive and -Negative Breast Cancer Cells by Prolonging Radiation-Induced DNA Damage

    PubMed Central

    Khoram, Nastaran Masoudi; Bigdeli, Bahareh; Nikoofar, Alireza

    2016-01-01

    Purpose Breast cancer is an important cause of death among women. The development of radioresistance in breast cancer leads to recurrence after radiotherapy. Caffeic acid phenethyl ester (CAPE), a polyphenolic compound of honeybee propolis, is known to have anticancer properties. In this study, we examined whether CAPE enhanced the radiation sensitivity of MDA-MB-231 (estrogen receptor-negative) and T47D (estrogen receptor-positive) cell lines. Methods The cytotoxic effect of CAPE on MDA-MB-231 and T47D breast cancer cells was evaluated by performing an 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. To assess clonogenic ability, MDA-MB-231 and T47D cells were treated with CAPE (1 µM) for 72 hours before irradiation, and then, a colony assay was performed. A comet assay was used to determine the number of DNA strand breaks at four different times. Results CAPE decreased the viability of both cell lines in a dose- and time-dependent manner. In the clonogenic assay, pretreatment of cells with CAPE before irradiation significantly reduced the surviving fraction of MDA-MB-231 cells at doses of 6 and 8 Gy. A reduction in the surviving fraction of T47D cells was observed relative to MDA-MB-231 at lower doses of radiation. Additionally, CAPE maintained radiation-induced DNA damage in T47D cells for a longer period than in MDA-MB-231 cells. Conclusion Our results indicate that CAPE impairs DNA damage repair immediately after irradiation. The induction of radiosensitivity by CAPE in radioresistant breast cancer cells may be caused by prolonged DNA damage. PMID:27066092

  16. Phase segregation of polymerizable lipids to construct filters for separating lipid-membrane-embedded species

    PubMed Central

    Hu, Shu-Kai; Chen, Ya-Ming; Chao, Ling

    2014-01-01

    Supported lipid bilayer (SLB) platforms have been developed to transport and separate membrane-embedded species in the species' native bilayer environment. In this study, we used the phase segregation phenomenon of lipid mixtures containing a polymerizable diacetylene phospholipid, 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DiynePC), and a nonpolymerizable phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), to create filter barrier structures in SLBs. Upon exposing the phase segregated samples to UV light, the DiynePC-rich domains could become crosslinked and remain fixed on the surface of the support, while the DOPC-rich regions, where no crosslinking could happen, could be removed later by detergent washing, and thus became the void regions in the filter. During the filter fabrication process, we used the laminar flow configuration in a microfluidic channel to control the spatial locations of the feed region and filter region in the SLB. The flow in a microfluidic channel was also used to apply a strong hydrodynamic shear stress to the SLB to transport the membrane-embedded species from the feed region to the filter region. We varied the DiynePC/DOPC molar ratio from 60/40 to 80/20 to adjust the cutoff size of the filter barriers and used two model membrane-embedded species of different sizes to examine the filtering capability. One of the model species, Texas Red 1,2-dihexa-decanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (Texas Red DHPE), had a single-lipid size, and the other species, cholera toxin subunit B-GM1 complex, had a multilipid size. When the DiynePC/DOPC molar ratio was 60/40, both species had high penetration ratios in the filter region. However, when the ratio was increased to 70/30, only the Texas Red DHPE, which was the smaller of the two model species, could penetrate the filter to a considerable extent. When the ratio was increased to 80/20, neither of the model species could penetrate the filter

  17. Facile Fabrication of Polymerizable Ionic Liquid Based-Gel Beads via Thiol-ene Chemistry.

    PubMed

    Taghavikish, Mona; Subianto, Surya; Dutta, Naba Kumar; Choudhury, Namita Roy

    2015-08-12

    Multipurpose gel beads prepared from natural or synthetic polymers have received significant attention in various applications such as drug delivery, coatings, and electrolytes because of their versatility and unique performance as micro- and nanocontainers.1 However, comparatively little work has been done on poly(ionic liquid)-based materials despite their unique ionic characteristics. Thus, in this contribution we report the facile preparation of polymerizable ionic liquid-based gel beads using thiol-ene click chemistry. This novel system incorporates pentaerythritol tetra (3-mercaptopropionate) (PETKMP) and 1,4-di(vinylimidazolium) butane bisbromide in a thiol-ene-based photopolymerization to fabricate the gel beads. Their chemical structure, thermal and mechanical properties have been investigated using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). The gel beads possess low Tg and their ionic functionalities attribute self-healing properties and their ability to uptake small molecules or organic compounds offers their potential use as pH sensing material and macrocontainers.

  18. Reconstitution of rhodopsin into polymerizable planar supported lipid bilayers: influence of dienoyl monomer structure on photoactivation.

    PubMed

    Subramaniam, Varuni; D'Ambruoso, Gemma D; Hall, H K; Wysocki, Ronald J; Brown, Michael F; Saavedra, S Scott

    2008-10-07

    G-protein-coupled receptors (GPCRs) play key roles in cellular signal transduction and many are pharmacologically important targets for drug discovery. GPCRs can be reconstituted in planar supported lipid bilayers (PSLBs) with retention of activity, which has led to development of GPCR-based biosensors and biochips. However, PSLBs composed of natural lipids lack the high stability desired for many technological applications. One strategy is to use synthetic lipid monomers that can be polymerized to form robust bilayers. A key question is how lipid polymerization affects GPCR structure and activity. Here we have investigated the photochemical activity of bovine rhodopsin (Rho), a model GPCR, reconstituted into PSLBs composed of lipids having one or two polymerizable dienoyl moieties located in different regions of the acyl chains. Plasmon waveguide resonance spectroscopy was used to compare the degree of Rho photoactivation in fluid and poly(lipid) PSLBs. The position of the dienoyl moiety was found to have a significant effect: polymerization near the glycerol backbone significantly attenuates Rho activity whereas polymerization near the acyl chain termini does not. Differences in cross-link density near the acyl chain termini also do not affect Rho activity. In unpolymerized PSLBs, an equimolar mixture of phosphatidylethanolamine and phosphatidylcholine (PC) lipids enhances activity relative to pure PC; however after polymerization, the enhancement is eliminated which is attributed to stabilization of the membrane lamellar phase. These results should provide guidance for the design of robust lipid bilayers functionalized with transmembrane proteins for use in membrane-based biochips and biosensors.

  19. Novel self-healing dental resin with microcapsules of polymerizable triethylene glycol dimethacrylate and N,N-dihydroxyethyl-p-toluidine.

    PubMed

    Wu, Junling; Weir, Michael D; Zhang, Qiang; Zhou, Chuanjian; Melo, Mary Anne S; Xu, Hockin H K

    2016-02-01

    Bulk fracture is one of the primary reasons for resin-based dental restoration failures. To date, there has been no report on the use of polymerizable dental monomers with acceptable biocompatibility to develop a resin with substantial self-healing capability. The objectives of this study were to: (1) develop a self-healing resin containing microcapsules with triethylene glycol dimethacrylate (TEGDMA)-N,N-dihydroxyethyl-p-toluidine (DHEPT) healing liquid in poly(urea-formaldehyde) (PUF) shells for the first time, and (2) determine the physical and mechanical properties, self-healing efficiency, and fibroblast cytotoxicity. Microcapsules of polymerizable TEGDMA-DHEPT in PUF were prepared via an in situ polymerization method. Microcapsules were added into a BisGMA-TEGDMA resin at microcapsule mass fractions of 0%, 5%, 10%, 15% and 20%. A flexural test was used to measure composite strength and elastic modulus. A single edge V-notched beam method was used to measure fracture toughness KIC and self-healing efficiency. Flexural strength and elastic modulus (mean±sd; n=6) of resin containing 5-15% microcapsules were similar to control without microcapsules (p>0.1). Adding microcapsules into the resin increased the virgin KIC, which was about 40% higher at 15% microcapsules than that with 0% microcapsules (p<0.05). Specimens were fractured and healed, then fractured again to measure the healed KIC. A self-healing efficiency of about 65% in KIC recovery was obtained with 10-20% microcapsules. All specimens with 0-20% microcapsules had fibroblast viability similar to control without resin eluents (p>0.1). Self-healing dental resin containing microcapsules with polymerizable TEGDMA-DHEPT healing liquid in PUF shells were prepared for the first time with excellent self-healing capability. These microcapsules and self-healing resins containing them may be promising for dental restorations to heal cracks/damage and increase durability. Copyright © 2015 Academy of Dental

  20. Fiberite 954: cyanate ester systems

    NASA Astrophysics Data System (ADS)

    Almen, G. R.; Mackenzie, P. D.; Malhotra, Vinay; Maskell, R. K.

    1992-09-01

    Cost and weight savings achieved by the use of composites have allowed these materials to displace their metal counterparts in space applications. Epoxy matrix based carbon fiber reinforced composites, such as Fiberite 934, have been used for a number of years. Relative to these systems, cyanate esters offer a number of unique attributes such as excellent hydrophobicity and electrical properties, reduced residual stress and better microcrack resistance, and improved radiation resistance. The significant reduction in water sorption and the low response to uptake make it possible to achieve much improved dimensional stability and reduced outgassing. These features may be used to advantage in electro-optical applications in space. ICI Fiberite has developed cyanate ester based prepreg systems that are penetrating the satellite, military radome and structural aerospace markets. Features of these systems will be presented and the properties of the cyanate ester based prepreg, Fiberite 954- 3, will be compared to those of Fiberite 934.

  1. Solvent effect in keto-enol tautomerism for a polymerizable β-ketonitrile monomer. Spectroscopy and theoretical study

    NASA Astrophysics Data System (ADS)

    Giussi, Juan M.; Gastaca, Belén; Lavecchia, Martín J.; Schiavoni, Mercedes; Susana Cortizo, M.; Allegretti, Patricia E.

    2015-02-01

    The beta-ketonitrile 2-methyl-5-phenyl-3-oxo-4-pentenenitrile, a polymerizable monomer, exists in two important tautomeric forms, keto and enol isomers. This compound has been studied as monomer in polymerization reactions and the resulting polymers have been applied in fields of nanotechnology. Currently, these are being studied in nanomedicine. To understand the tautomeric equilibrium, we have studied this compound in solution by NMR spectrometry. Correlation with DFT calculations has been carried out in order to understand the system behavior. The results found in this work, both by experiments and calculations, show that the enol content increases with solvent polarity.

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  4. [Development of novel self-healing and antibacterial resin composite containing microcapsules filled with polymerizable healing monomer].

    PubMed

    Wu, Junling; Zhang, Qiang; Zhu, Ting; Ge, Jianhua; Zhou, Chuanjian

    2015-08-01

    To develop novel self- healing and antibacterial resin composite containing microcapsules filled with polymerizable healing monomer, and to measure its properties for further clinical application. Microcapsules filled with healing monomer of triethylene glycol dimethacrylate were synthesized according to methods introduced in the previous research. Microcapsules were added into novel resin composite containing nano-antibacterial silica fillers grafted with long chain alkyl quaternary ammonium at mass fractions of 0, 2.5%, 5.0%, 7.5% or 10.0%. A commercial resin composite (Tetric N-Ceram) was used as control. Flexural test was used to measure resin composite flexural strength and elastic modulus. The single edge V-notched beam method was used to measure fracture toughness and self-healing efficiency. Scanning electron microscope (SEM) was used to examine the fractured surface of selected specimen for investigation of fracture mechanisms. The flexural strength and elastic modulus of the resin composite were (96.4 ± 14.3) MPa and (6.2 ± 1.1) GPa respectively after incorporation of microcapsules up to 7.5%, and no significant difference was found between the experimental group and the control group [(99.1 ± 11.9) MPa and (6.1 ± 1.1) GPa] (P>0.05). The self-healing efficiency of (66.8 ± 7.0)% and (79.3 ± 9.7)% were achieved for resin composite with microcapsule mass fractions at 7.5% and 10.0%. SEM image showed that irregular films covered the fractured surface. Conclusions This novel self-healing and antibacterial resin composite containing microcapsules filled with polymerizable healing monomer exhibited a promising self- healing ability, which enabled itself well up for combating bulk fracture and secondary caries in clinical application.

  5. Controllable synthesis of new polymerizable macrosurfactants via CCTP and RAFT techniques and investigation of their performance in emulsion polymerization.

    PubMed

    Chen, Li; Yan, Lili; Li, Qing; Wang, Caifeng; Chen, Su

    2010-02-02

    We reported herein the synthesis of poly(methacrylic acid)-b-poly(butyl acrylate) (PMAA-b-PBA) block copolymers (surfmers) and their performance as novel polymerizable macrosurfactants in emulsion polymerization. The surfmers bearing terminal unsaturated carbon-carbon double bonds were first successfully designed and sythesized via catalytic chain transfer polymerization (CCTP) and radical addition-fragmentation polymerization (RAFT) techniques. The structures of surfmers were characterized by Raman spectra, nuclear magnetic resonance ((1)H NMR), and gel permeation chromatography (GPC). The critical micelle concentration of surfmers was determined. Subsequently, the surfmers were used as emulsifier to prepare polyacrylate latexes (PA-surf). The influence of the surfmer concentration as well as PMAA and PBA chain segment ratios of surfmer on their performance in emulsion polymerization was discussed thoroughly. The particle size, amount of coagulum, and stability against electrolyte solutions of the latexes were evaluated. Also, the relations between monomer conversion in emulsion polymerization, polymerization rate, emulsion particle size, surface tension, and reaction time were investigated, which showed some interesting information for the probable mechanism underlying this emulsion polymerization system. Atomic force microscopy (AFM) and attenuated total reflection Fourier transform infrared spectra (ATR FT-IR) were performed to investigate the surface morphology and component distribution of the latex films. The results show high efficiency of these surfmers in emulsion polymerization, suggesting that the resultant PMAA-b-PBA block copolymers act not only as the emulsifier but also as the stabilizer of monomer droplets as well as the so-called comonomer.

  6. Physical Properties and Biological Activity of Poly(butyl acrylate–styrene) Nanoparticle Emulsions Prepared with Conventional and Polymerizable Surfactants

    PubMed Central

    Garay-Jimenez, Julio C.; Gergeres, Danielle; Young, Ashley; Dickey, Sonja; Lim, Daniel V.; Turos, Edward

    2009-01-01

    Recent efforts in our laboratory have explored the use of polyacrylate nanoparticles in aqueous media as stable emulsions for potential applications in treating drug-resistant bacterial infections. These emulsions are made by emulsion polymerization of acrylated antibiotic compounds in a mixture of butyl acrylate and styrene (7:3 w:w) using sodium dodecyl sulfate (SDS) as a surfactant. Prior work in our group established that the emulsions required purification to remove toxicity associated with extraneous surfactant present in the media. This paper summarizes our investigations of poly(butyl acrylate-styrene) emulsions made using anionic, cationic, zwitterionic, and non-charged (amphiphilic) surfactants, as well as attachable surfactant monomers (surfmers), comparing the cytotoxicity and microbiological activity levels of the emulsion both before and after purification. Our results show that the attachment of a polymerizable surfmer onto the matrix of the nanoparticle neither improves nor diminishes cytotoxic or antibacterial effects of the emulsion, regardless of whether the emulsions are purified or not, and that the optimal properties are associated with the use of the non-ionic surfactants versus those carrying anionic, cationic, or zwitterionic charge. Incorporation of an N-thiolated β-lactam antibacterial agent onto the nanoparticle matrix via covalent attachment endows the emulsion with antibiotic properties against pathogenic bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), without changing the physical properties of the nanoparticles or their emulsions. PMID:19523413

  7. Guanidinium-Based Polymerizable Surfactant as a Multifunctional Molecule for Controlled Synthesis of Nanostructured Materials with Tunable Morphologies.

    PubMed

    Ji, Jingwei; Zhu, Wei; Li, Jian; Wang, Peng; Liang, Yun; Zhang, Wanlin; Yin, Xianpeng; Wu, Baozhen; Li, Guangtao

    2017-06-07

    Rationally and efficiently controlling the morphology of nanomaterials plays a crucial role in significantly enhancing their functional properties and expending their applications. In this work, a strategy for controlled synthesis of diverse nanostructured materials with tunable morphologies was developed using a guanidinium-based surfactant with a polymerizable pyrrole unit as a multifunctional molecule that can serve not only as a structure-directing agent for mesostucture formation but also as a monomer and carbon source. The unique self-assembly behavior of the guanidinium head group under different conditions allows the synthesized surfactants to form different aggregates and thus to produce silica nanomaterials with multiple morphologies (such as sphere, disk, fiber, and cocoon) in conjunction with sol-gel chemistry. Besides the mesostructured silicates, by further exploring the polymerization and carbonization features of pyrrole units that were densely packed in the formed silica nanochannels, diverse nanostructured materials such as mesostructured conducting polymers, carbon materials, and metal-nanoparticle (NP)-decorated forms could also be easily obtained in one-pot fashion for various applications, such as energy storage and catalysis. As a demonstration, carbon nanotubes and Pd-NP-doped hollow carbon spheres were fabricated, which exhibited good specific capacitance (101.7 F g(-1)) at the scan rates of 5 mV s(-1) and excellent catalytic performance (100% conversion for three cycles) in the Suzuki C-C coupling reaction, respectively. All of the results indicate that our strategy may open a new avenue for efficiently accessing diverse nanostructured materials with tunable morphologies for wide applications.

  8. Radiation

    NASA Image and Video Library

    Outside the protective cocoon of Earth's atmosphere, the universe is full of harmful radiation. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radi...

  9. Kapok oil methyl esters

    USDA-ARS?s Scientific Manuscript database

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

  10. Kenaf methyl esters

    USDA-ARS?s Scientific Manuscript database

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

  11. The ESTER project

    NASA Astrophysics Data System (ADS)

    Rieutord, M.; Dintrans, B.; Lignières, F.; Corbard, T.; Pichon, B.

    2005-12-01

    The ESTER project aims at building a stellar evolution code in two dimensions of space for the study of effects of rotation. The numerical scheme is based on spectral methods with a spherical harmonic decomposition in the horizontal direction and a Chebyshev polynomial expansion in the vertical direction. Coordinates adapted to the centrifugally distorted shape are mapped to spherical coordinates. First tests on rotating polytropes are presented.

  12. Effects of the mixture composition on the microstructure of polymer matrix and light scattering properties of liquid crystal/photo-polymerizable monomers composites

    NASA Astrophysics Data System (ADS)

    Li, Wenbo; Cheng, Zihui; Pan, Guohui; Liu, Huijing; Cao, Hui; Yang, Zhou; Yang, Huai

    2008-10-01

    The microstructure and electro-optical effects based on light scattering have been investigated for nematic liquid crystal (LC)/photo-polymerizable monomers composites. It was demonstrated that the optimum electro-optical properties of the composites were obtained when the LC content was between 60 and 70 wt%. Furthermore, the variety of the light scattering intensity for the composites in the wavelength region of 300-2500 nm was studied experimentally and theoretically with the combination of three kinds of classical light scattering theories: the Rayleigh-Gans (RG) approach, the anomalous diffraction (AD) approach, and the geometrical optics (GO) approach. Then a simple mathematic simulation was established to describe the relationship between the transmittance and the incident wavelength in this wavelength region.

  13. Nanosized Spinel Li4Ti5O12 Anode Material Prepared by Gel-polymer Method using Furfuryl Alcohol as Polymerizable Solvent

    NASA Astrophysics Data System (ADS)

    Ding, Chu-xiong; Bai, Yao-cai; Wei, Cong; Chen, Chun-hua

    2012-08-01

    Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using titanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller (BET) analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 °C or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfactant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained.

  14. Guest-responsive covalent frameworks by the cross-linking of liquid-crystalline salts: tuning of lattice flexibility by the design of polymerizable units.

    PubMed

    Ishida, Yasuhiro; Sakata, Hiroaki; Achalkumar, Ammathnadu S; Yamada, Kuniyo; Matsuoka, Yuki; Iwahashi, Nobutaka; Amano, Sayaka; Saigo, Kazuhiko

    2011-12-23

    Cross-linked polymers prepared by the in-situ polymerization of liquid-crystalline salts were found to work as solid-state hosts with a flexible framework. As a component of such hosts, four kinds of polymerizable amphiphilic carboxylic acids bearing alkyl chains with acryloyloxy (A), dienyl (D), and/or nonreactive (N) chain ends (monomeric carboxylic acids; M(AAA), M(ANA), M(DDD), and M(DND)) were used. The carboxylic acids were mixed with an equimolar amount of a template unit, (1R,2S)-norephedrine (guest amine; G(RS)), to form the corresponding salts. Every salt exhibited a rectangular columnar LC phase at room temperature, which was successfully polymerized by (60)Co γ-ray-induced polymerization without serious structural disordering to afford the salt of cross-linked carboxylic acid (polymeric carboxylic acid; P(AAA), P(ANA), P(DDD), and P(DND)) with G(RS) . Owing to the noncovalency of the interactions between the polymer framework P and the template G(RS), the cross-linked polymers could reversibly release and capture a meaningful amount of G(RS). In response to the desorption and adsorption of G(RS), the cross-linked polymers dramatically switched their nanoscale structural order. A systematic comparison of the polymers revealed that the choice of polymerizable groups has a significant influence on the properties of the resultant polymer frameworks as solid-state hosts. Among these polymers, P(DDD) was found to be an excellent solid-state host, in terms of guest-releasing/capturing ability, guest-recognition ability, durability to repetitive usage, and unique structural switching mode.

  15. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  16. Lipoate ester multifunctional lubricant additives

    USDA-ARS?s Scientific Manuscript database

    Seven lipoate esters were synthesized by esterification of lipoic acid with different structures of alcohols in the presence of a solid acid catalyst and without solvent. The esters were obtained in good yield, characterized using 1H NMR and GPC; and their physical properties investigated. Four of t...

  17. Synthesis of pyromellitic acid esters

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

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

    PubMed

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

    2008-11-26

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

  19. Telechelic Poly(2-oxazoline)s with a biocidal and a polymerizable terminal as collagenase inhibiting additive for long-term active antimicrobial dental materials

    PubMed Central

    Fik, Christoph P.; Konieczny, Stefan; Pashley, David H.; Waschinski, Christian J.; Ladisch, Reinhild S.; Salz, Ulrich; Bock, Thorsten; Tiller, Joerg C.

    2015-01-01

    Although modern dental repair materials show excellent mechanical and adhesion properties, they still face two major problems: First, any microbes that remain alive below the composite fillings actively decompose dentin and thus, subsequently cause secondary caries. Second, even if those microbes are killed, the extracellular proteases such as MMP, remain active and can still degrade collagenousdental tissue. In order to address both problems, a poly(2-methyloxazoline) with a biocidal quaternary ammonium and a polymerizable methacrylate terminal was explored as additive for a commercial dental adhesive. It could be demonstrated that the adhesive rendered the adhesive contact-active antimicrobial against S. mutans at a concentration of only 2.5 wt% and even constant washing with water for 101 days did not diminish this effect. Increasing the amount of the additive to 5 wt% allowed killing S. mutans cells in the tubuli of bovinedentin upon application of the adhesive. Further, the additive fully inhibited bacterial collagenase at a concentration of 0.5 wt% and reduced human recombinant collagenase MMP-9 to 13% of its original activity at that concentration. Human MMPs naturally bound to dentin were inhibited by more than 96% in a medium containing 5 wt% of the additive. Moreover, no adverse effect on the enamel/dentine shear bond strength was detected in combination with a dental composite. PMID:25130877

  20. Synthesis of nanostructured LiTi{sub 2}(PO{sub 4}){sub 3} powder by a Pechini-type polymerizable complex method

    SciTech Connect

    Mariappan, C.R.; Galven, C.; Crosnier-Lopez, M.-P.; Le Berre, F.; Bohnke, O. . E-mail: odile.bohnke@univ-lemans.fr

    2006-02-15

    The nanostructured NASICON-type LiTi{sub 2}(PO{sub 4}){sub 3} (LTP) material has been synthesized by Pechini-type polymerizable complex method. The use of water-soluble ammonium citratoperoxotitanate (IV) metal complex instead of alkoxides as precursor allows to prepare monophase material. Thermal analyses have been carried out on the powder precursor to check the weight loss and synthesis temperature. X-ray powder diffraction analysis (XRD) has been performed on the LTP powder obtained after heating the powder precursor over a temperature range from 550 to 1050 deg. C for 2 h. By varying the molar ratio of citric acid to metal ion (CA/Ti) and citric acid to ethylene glycol (CA/EG), the grain size of the LTP powder could be modified. The formation of small and well-crystalline grains, in the order of 50-125 nm in size, has been determined from the XRD patterns and confirmed by transmission electron microscopy.

  1. Synthesis and Utility of Dihydropyridine Boronic Esters**

    PubMed Central

    Panda, Santanu; Coffin, Aaron; Nguyen, Q. Nhu; Tantillo, Dean; Ready, Joseph M.

    2016-01-01

    When activated by an acylating agent, pyridine boronic esters react with organometallic reagents to form a dihydropyridine boronic ester. This intermediate allows access to a number of valuable substituted pyridine, dihydropyridine and piperidine products. PMID:26694785

  2. Synthesis and Utility of Dihydropyridine Boronic Esters.

    PubMed

    Panda, Santanu; Coffin, Aaron; Nguyen, Q Nhu; Tantillo, Dean J; Ready, Joseph M

    2016-02-05

    When activated by an acylating agent, pyridine boronic esters react with organometallic reagents to form a dihydropyridine boronic ester. This intermediate allows access to a number of valuable substituted pyridine, dihydropyridine, and piperidine products.

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

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  4. REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

    EPA Science Inventory

    Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

  5. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Methylamine esters. 721.3034 Section... Substances § 721.3034 Methylamine esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as methylamine esters (PMN P-94-982) is subject...

  6. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under this...

  7. 40 CFR 721.537 - Organosilane ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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) is...

  8. 40 CFR 721.537 - Organosilane ester.

    Code of Federal Regulations, 2010 CFR

    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) is...

  9. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  10. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  11. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  12. 40 CFR 721.537 - Organosilane ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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)...

  13. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  14. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  15. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Methylamine esters. 721.3034 Section... Substances § 721.3034 Methylamine esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as methylamine esters (PMN P-94-982) is...

  16. 40 CFR 721.3034 - Methylamine esters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  17. Regioselective Synthesis of Cellulose Ester Homopolymers

    Treesearch

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  18. Influence of a polymerizable eugenol derivative on the antibacterial activity and wettability of a resin composite for intracanal post cementation and core build-up restoration.

    PubMed

    Almaroof, A; Niazi, S A; Rojo, L; Mannocci, F; Deb, S

    2016-07-01

    species with values in the range 2.7-6.1 following the order E. faecalispolymerizable formulations provides a novel approach to yield intrinsically antibacterial resin composites for different dental applications. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. Metabolic properties of phosphonate esters.

    PubMed

    Somogyi, G; Buchwald, P; Bodor, N

    2004-05-01

    The object of the present work was to investigate the difference in the metabolism of the phosphonate derivatives of primary or secondary hydroxyl groups. To study the phosphorolytic cleavage of such P-O bonds, zidovudine (AZT) hexanoyloxymethyl-methylphosphonate (HOM-AZT-P), an ester of a primary OH functionality, and methyl-pivaloyloxymethyl-testosterylphosphonate (POM-T-P), an ester of a secondary OH functionality, were prepared. The actions of pure enzymes such as alkaline phosphatase and phosphodiesterase on the corresponding phosphonate compounds (AZT-P and T-P) were investigated at various pH values. The phosphonate derivative of the secondary hydroxyl group of testosterone proved completely resistant to such phosphorolytic attacks, and release of free testosterone could not be detected. The phosphonate derivative of the primary hydroxyl group of zidovudine proved resistant to phosphodiesterase, but not to alkaline phosphatase, and in this second case, release of free zidovudine could be detected.

  20. ESTER: Evolution STEllaire en Rotation

    NASA Astrophysics Data System (ADS)

    Rieutord, Michel

    2013-05-01

    The ESTER code computes the steady state of an isolated star of mass larger than two solar masses. The only convective region computed as such is the core where isentropy is assumed. ESTER provides solutions of the partial differential equations, for the pressure, density, temperature, angular velocity and meridional velocity for the whole volume. The angular velocity (differential rotation) and meridional circulation are computed consistently with the structure and are driven by the baroclinic torque. The code uses spectral methods, both radially and horizontally, with spherical harmonics and Chebyshev polynomials. The iterations follow Newton's algorithm. The code is object-oriented and is written in C++; a python suite allows an easy visualization of the results. While running, PGPLOT graphs are displayed to show evolution of the iterations.

  1. Methods of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-08-03

    A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

  2. (Meth)Acrylate Vinyl Ester Hybrid Polymerizations

    PubMed Central

    Lee, TaiYeon; Cramer, Neil; Hoyle, Charles; Stansbury, Jeffrey

    2009-01-01

    In this study vinyl ester monomers were synthesized by an amine catalyzed Michael addition reaction between a multifunctional thiol and the acrylate double bond of vinyl acrylate. The copolymerization behavior of both methacrylate/vinyl ester and acrylate/vinyl ester systems was studied with near-infrared spectroscopy. In acrylate/vinyl ester systems, the acrylate groups polymerize faster than the vinyl ester groups resulting in an overall conversion of 80% for acrylate double bonds in the acrylate/vinyl ester system relative to only 50% in the bulk acrylate system. In the methacrylate/vinyl ester systems, the difference in reactivity is even more pronounced resulting in two distinguishable polymerization regimes, one dominated by methacrylate polymerization and a second dominated by vinyl ester polymerization. A faster polymerization rate and higher overall conversion of the methacrylate double bonds is thus achieved relative to polymerization of the pure methacrylate system. The methacrylate conversion in the methacrylate/vinyl ester system is near 100% compared to only ~60% in the pure methacrylate system. Utilizing hydrophilic vinyl ester and hydrophobic methacrylate monomers, polymerization-induced phase separation is observed. The phase separated domain size is on the order of ~1 μm under the polymerization conditions. The phase separated domains become larger and more distinct with slower polymerization and correspondingly increased time for diffusion. PMID:19855853

  3. L-Arabinose (pyranose and furanose rings)-branched poly (vinylalcohol): enzymatic synthesis of the sugar esters followed by free radical polymerization.

    PubMed

    Rodrigues Borges, Maurício; Balaban, Rosangela de Carvalho

    2014-12-20

    Herein this study reports the successful synthesis of a new poly(vinyl alcohol) (PVA), containing L-arabinose (L-arabinopyranose and arabinofuranose isomers) branched in only two steps: (1) production of polymerizable monomers of L-arabinose isomers (pyranose and furanose forms) through enzymatic synthesis using alkaline protease from Bacillus subtilis as catalyst and two substrates: L-arabinose and Divinyl Adipate (DVA) in N,N-dimethylformamide (DMF); (2) radical polymerization of the monomers, using an initiator system consisting of potassium persulfate and hydrogen peroxide in water. The transesterification of DVA with L-arabinose was monitored via qualitative analysis by TLC, confirming the formation of the vinyl sugar ester. The acylation occurred on the two different cyclic conformations of the L-arabinose which coexist in equilibrium: (α/β) arabinofuranose and (α/β) arabinopyranose. The acylation positions and the chemical structure of the 5-O-vinyl adipoyl L-arabinofuranose and 4-O-vinyl adipolyl L-arabinopyranose formed were determined by 13C NMR. The surface activity of the L-arabinose esters mixture (monomers) was compared with a commercial product based on phenol formaldehyde polyoxyalkylene polyamine, largely used as surfactant in many industries. FTIR spectroscopy of the sugar ester monomers and the respective polymer were compared revealing the disappearance of the vinyl group in the polymer spectrum. The polymer number-average molar mass (Mn) and the weight-average molar mass (Mw) were determined by gel permeation chromatography (GPC) presenting the following results: 2.9 × 10(4) Da and 7.2 × 10(4) Da, respectively, and polydispersity (Mw/Mn) equal to 2.48.

  4. Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide Oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodornus J. (Inventor); Weiser, Erik S. (Inventor); SaintClair, Terry L. (Inventor)

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  5. Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide Oligomers

    NASA Technical Reports Server (NTRS)

    Dingemans, Theodornus J. (Inventor); Weiser, Erik S. (Inventor); SaintClair, Terry L. (Inventor)

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  6. Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

  7. Nonaqueous enzymatic synthesis of ester fuels

    SciTech Connect

    Olson, E.S.; Singh, H.K.; Yagelowich, M.L.

    1993-12-31

    The application of nonaqueous enzyme slurries for the production of fatty ester fuels from coal-derived alcohols and triglyceride oils was investigated. Nonaqueous enzyme systems can greatly facilitate many organic reactions, especially those that result in formation of esters and amides. The production of biomass ester fuels from triglyceride oils involves transesterification of the triglyceride with an alcohol. Phenolic tars from coal gasification wastes were fractionated and treated to convert them to an alcohol form, and the intermediate alcohols were converted to the fatty ester in a nonaqueous lipase system. Lipases in a variety of organic solvents were intensively investigated for acylation of coal derivatives containing alcohol functional groups. The two-step process transformed the black poorly soluble phenolics to clean paraffin-soluble esters. Diesel testing demonstrated that the product esters could be substituted for diesel fuels.

  8. Stereoselective synthesis of functionalized gamma-amino esters: azetidinium salts and epoxy esters.

    PubMed

    Concellón, José M; Riego, Estela; Bernad, Pablo L

    2002-04-18

    Addition of several lithium ester enolates to chiral 1-aminoalkyl chloromethyl ketones 1 affords enantiomerically pure 3-hydroxyazetidinium salts 3 or 3-(1'-aminoalkyl)-3,4-epoxy esters 4, depending on the reaction conditions. [reaction: see text

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

    DTIC Science & Technology

    2017-05-29

    dry)  150 – 300 (wet) • Resin viscosity suitable for filament winding • Compatible with thermoplastic reinforcements • Onset of weight loss...lander are made from M55J/cyanate ester composites • The solar panel supports on the MESSENGER space probe use cyanate ester composite tie layers...Fusion reactor, photo courtesy of Gerritse ((Wikimedia Commons) • Unique cyanate ester composites have been designed by NASA for use as instrument

  10. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are derived...

  11. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are derived...

  12. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are derived...

  13. Method of making a cyanate ester foam

    DOEpatents

    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.

  14. Prodrug behaviour of nicotinoylmorphine esters.

    PubMed

    Broekkamp, C L; Oosterloo, S K; Rijk, H W

    1988-06-01

    Morphine and its nicotinoyl esters, dinicotinoylmorphine (nicomorphine), 6-mononicotinoylmorphine (6-MNM) and 3-mononicotinoylmorphine (3-MNM) were tested in mice for central activity to obtain time-effect profiles of these compounds in rats. Two effects, analgesia with the hot plate test and locomotor stimulation in activity cages were measured and nicomorphine, 6-MNM and 3-MNM were found to have a faster onset of action compared with morphine. The effects of 3-MNM and morphine lasted longer than the effect of nicomorphine and 6-MNM. The prodrug behaviour of 3-MNM and nicomorphine for morphine and 6-MNM, respectively, is discussed.

  15. Characterization and Process Development of Cyanate Ester Resin Composites

    SciTech Connect

    Frame, B.J.

    1999-05-23

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

  16. Spectroscopy reveals that ethyl esters interact with proteins in wine.

    PubMed

    Di Gaspero, Mattia; Ruzza, Paolo; Hussain, Rohanah; Vincenzi, Simone; Biondi, Barbara; Gazzola, Diana; Siligardi, Giuliano; Curioni, Andrea

    2017-02-15

    Impairment of wine aroma after vinification is frequently associated to bentonite treatments and this can be the result of protein removal, as recently demonstrated for ethyl esters. To evaluate the existence of an interaction between wine proteins and ethyl esters, the effects induced by these fermentative aroma compounds on the secondary structure and stability of VVTL1, a Thaumatin-like protein purified from wine, was analyzed by Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy. The secondary structure of wine VVTL1 was not strongly affected by the presence of selected ethyl esters. In contrast, VVTL1 stability was slightly increased by the addition of ethyl-octanoate, -decanoate and -dodecanoate, but decreased by ethyl-hexanoate. This indicates the existence of an interaction between VVTL1 and at least some aroma compounds produced during fermentation. The data suggest that proteins removal from wine by bentonite can result in indirect removal of at least some aroma compounds associated with them. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    PubMed

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

    2014-11-01

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

  19. 40 CFR 721.10664 - Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., reaction products with alkenoic acid alkyl esters and diamine (generic). 721.10664 Section 721.10664... Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). (a... generically as alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and...

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

    SciTech Connect

    Frame, B.J.

    1998-03-01

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

  1. Sugar Ester Compounds for Arthropod Control

    USDA-ARS?s Scientific Manuscript database

    Sugar esters, also known as acyl sugars or polyol esters, are a class of compounds that are internationally recognized as food additives. They are commonly used in bakery goods, drugs, cosmetics, food packaging plastics, and in other applications because of their surfactant and emulsifying properti...

  2. Expanding ester biosynthesis in Escherichia coli

    PubMed Central

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

    2015-01-01

    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. PMID:24609358

  3. 40 CFR 721.537 - Organosilane ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 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)...

  4. 40 CFR 721.537 - Organosilane ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 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)...

  5. Stable and versatile active acridinium esters II.

    PubMed

    Razavi, Z; McCapra, F

    2000-01-01

    The synthesis of acridinium esters with a linking group directly attached to the acridine nucleus is described. This strategy will allow the widest possible choice of variously substituted phenyl esters without restricting them to those structures bearing linking groups on the phenol. Copyright 2000 John Wiley & Sons, Ltd.

  6. Expanding ester biosynthesis in Escherichia coli.

    PubMed

    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.

  7. Briareolate Esters from the Gorgonian Briareum asbestinum

    PubMed Central

    Meginley, Rian J.; Gupta, Prasoon; Schulz, Thomas C.; McLean, Amanda B.; Robins, Allan J.; West, Lyndon M.

    2012-01-01

    Two new briarane diterpenoids briareolate esters J (1) and K (2) were isolated from the methanolic extract of the octocoral Briareum asbestinum collected off the coast of Boca Raton, Florida. The structures of briaranes 1 and 2 were elucidated by interpretation of spectroscopic data. Briareolate ester K (2) showed weak growth inhibition activity against human embryonic stem cells (BG02). PMID:23015768

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

    PubMed

    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. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Direct amidation of esters with nitroarenes

    PubMed Central

    Cheung, Chi Wai; Ploeger, Marten Leendert; Hu, Xile

    2017-01-01

    Esters are one of the most common functional groups in natural and synthetic products, and the one-step conversion of the ester group into other functional groups is an attractive strategy in organic synthesis. Direct amidation of esters is particularly appealing due to the omnipresence of the amide moiety in biomolecules, fine chemicals, and drug candidates. However, efficient methods for direct amidation of unactivated esters are still lacking. Here we report nickel-catalysed reductive coupling of unactivated esters with nitroarenes to furnish in one step a wide range of amides bearing functional groups relevant to the development of drugs and agrochemicals. The method has been used to expedite the syntheses of bio-active molecules and natural products, as well as their post-synthetic modifications. Preliminary mechanistic study indicates a reaction pathway distinct from conventional amidation methods using anilines as nitrogen sources. The work provides a novel and efficient method for amide synthesis. PMID:28345585

  10. Direct amidation of esters with nitroarenes

    NASA Astrophysics Data System (ADS)

    Cheung, Chi Wai; Ploeger, Marten Leendert; Hu, Xile

    2017-03-01

    Esters are one of the most common functional groups in natural and synthetic products, and the one-step conversion of the ester group into other functional groups is an attractive strategy in organic synthesis. Direct amidation of esters is particularly appealing due to the omnipresence of the amide moiety in biomolecules, fine chemicals, and drug candidates. However, efficient methods for direct amidation of unactivated esters are still lacking. Here we report nickel-catalysed reductive coupling of unactivated esters with nitroarenes to furnish in one step a wide range of amides bearing functional groups relevant to the development of drugs and agrochemicals. The method has been used to expedite the syntheses of bio-active molecules and natural products, as well as their post-synthetic modifications. Preliminary mechanistic study indicates a reaction pathway distinct from conventional amidation methods using anilines as nitrogen sources. The work provides a novel and efficient method for amide synthesis.

  11. WE-D-210-04: Radiation-Induced Polymerization of Ultrasound Contrast Agents in View of Non-Invasive Dosimetry in External Beam Radiation Therapy

    SciTech Connect

    Callens, M; Verboven, E; Van Den Abeele, K; D’Agostino, E; Pfeiffer, H; D’hooge, J

    2015-06-15

    Purpose: Ultrasound contrast agents (UCA’s) based on gas-filled microbubbles encapsulated by an amphiphilic shell are well established as safe and effective echo-enhancers in diagnostic imaging. In view of an alternative application of UCA’s, we investigated the use of targeted microbubbles as radiation sensors for external beam radiation therapy. As radiation induces permanent changes in the microbubble’s physico-chemical properties, a robust measure of these changes can provide a direct or indirect estimate of the applied radiation dose. For instance, by analyzing the ultrasonic dispersion characteristics of microbubble distributions before and after radiation treatment, an estimate of the radiation dose at the location of the irradiated volume can be made. To increase the radiation sensitivity of microbubbles, polymerizable diacetylene molecules can be incorporated into the shell. This study focuses on characterizing the acoustic response and quantifying the chemical modifications as a function of radiation dose. Methods: Lipid/diacetylene microbubbles were irradiated with a 6 MV photon beam using dose levels in the range of 0–150 Gy. The acoustic response of the microbubbles was monitored by ultrasonic through-transmission measurements in the range of 500 kHz to 20 MHz, thereby providing the dispersion relations of the phase velocity, attenuation and nonlinear coefficient. In addition, the radiation-induced chemical modifications were quantified using UV-VIS spectroscopy. Results: UV-VIS spectroscopy measurements indicate that ionizing radiation induces the polymerization of diacetylenes incorporated in the microbubble shell. The polymer yield strongly depends on the shell composition and the radiation-dose. The acoustic response is inherently related to the visco-elastic properties of the shell and is strongly influenced by the shell composition and the physico-chemical changes in the environment. Conclusion: Diacetylene-containing microbubbles are

  12. [Benzenedithiol esters with antimycotic activity].

    PubMed

    Pavanetto, F; Montanari, L; Modena, T; Mazza, M

    1982-06-01

    Some diesters of benzen-1,2-dithiol wit aliphatic and aromatic carboxylic acids were prepared and tested for in vitro antifungal activity. The diacetate and dipropionate of benzen-1,3- and 1,4-dithiol were used as comparison compounds. The substances (Table I; substances I leads to X) were obtained by condensation of benzenedithiols with suitable acylating agents. The fungistatic activity of the products was tested in vitro against the following fungal strains: Candida albicans, Candida tropicalis, Saccharomyces cerevisiae and Trichophyton mentagrophytes. The results show that the diester of benzen-1,2-dithiols with alkanoic acids (Table I) have marked antimycotic activity, much greater than that of clotrimazol. The diaroyl esters of benzen-1,2-dithiol and the diesters of benzen-1,3- and 1,4-dithiols are inactive or only slightly active.

  13. 40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721.10679 Section 721... Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester... identified generically as carboxylic acid, substituted alkylstannylene ester, reaction products...

  14. Sunflower oil methyl ester as diesel fuel

    SciTech Connect

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

    1982-01-01

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

  15. Identification of allyl esters in garlic cheese.

    PubMed

    Herbrand, Klaus; Hammerschmidt, Franz J; Brennecke, Stefan; Liebig, Margit; Lösing, Gerd; Schmidt, Claus Oliver; Gatfield, Ian; Krammer, Gerhard; Bertram, Heinz-Jürgen

    2007-09-19

    This study describes the identification of six allyl esters in a garlic cheese preparation and in a commercial cream cheese. The extracts were prepared by liquid/liquid extraction and concentrated by the SAFE process. The identification of the allyl esters of acetic, butyric, hexanoic, heptanoic, octanoic, and decanoic acids is based on the correlation of their mass spectrometric data and chromatographic retention time data obtained from the extracts with those of authentic standards. In addition to the gas chromatography (GC)/mass spectrometry analysis, the flavor ingredients were characterized by GC sniffing by a trained flavorist. Some of the esters were isolated by preparative GC.

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

    PubMed

    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.

  17. Photostability of alpha-tocopherol ester derivatives in solutions and liposomes. Spectroscopic and LC-MS studies.

    PubMed

    Neunert, Grazyna; Szwengiel, Artur; Walejko, Piotr; Witkowski, Stanislaw; Polewski, Krzysztof

    2016-07-01

    α-Tocopherol (Toc) is known to degrade to the tocopheroxyl radicals (Toc) by exposure to UV light irradiation. In the present study, the stability of Toc ester derivatives exposed to UV light was investigated and compared with Toc in organic solution and in phospholipid vesicles. To follow the depletion of Toc and its esters the absorbance and fluorescence methods were applied whereas degradation products were detected using LC-MS method. The irradiation with UVB light of air-equilibrated solutions of di-α-Tocopheryl malonate (DTMO), α-Tocopheryl malonate (TMO) and α-Tocopheryl succinate (TS) strongly modifies their absorption and fluorescence spectra. Upon UVB irradiation, absorption band at 279/285nm becomes less pronounced indicating the photodegradation of esters. During irradiation, the fluorescence maximum of esters at 305nm shifts to 326nm, a maximum characteristic for Toc. Photorecovery of Toc from its esters derivatives was finally confirmed by LC-MS method. Among studied esters, only α-tocopheryl nicotinate (TN) did not undergo depletion and appeared resistant to UVB radiation. Kinetic studies indicated that photoinduced transformation occurs through the first order consecutive reaction chain mechanism. The photodissociation of Toc esters in the liposomes occurred with one order of magnitude slower than in organic solvents. Using MS/MS method it was found that final stable product of irradiation was α-tocopheryl quinone (TQ), an animal and plant metabolite of Toc.

  18. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... Sucrose fatty acid esters. Sucrose fatty acid esters identified in this section may be safely used in accordance with the following prescribed conditions: (a) Sucrose fatty acid esters are the mono-, di-, and...

  19. Radiolabeled cholesteryl ethers trace LDL cholesteryl esters but not HDL cholesteryl esters in the rat.

    PubMed

    Terpstra, A H

    1995-01-06

    The intravascular metabolism of cholesteryl [1-14C]oleoyl ester and [1,2-3H(N)]cholesteryl palmityl ether was compared in the rat, an animal species without plasma cholesteryl ester transfer activity (CETA). The tracers had identical plasma disappearance rates when they were incorporated into human or rat low density lipoproteins (LDL). Fractional catabolic rates (FCR) were 0.081 +/- 0.014 h-1 and 0.080 +/- 0.013 h-1 for human LDL ester and ether and 0.098 +/- 0.007 h-1 and 0.101 +/- 0.007 h-1 for rat LDL ester and ether, respectively. In contrast, the ether had plasma disappearance rates that were 24%-25% lower than the ester when they were incorporated into human or rat high density lipoproteins (HDL). FCR were 0.230 +/- 0.020 and 0.173 +/- 0.030 h-1 for human HDL ester and ether and 0.131 +/- 0.020 h-1 and 0.100 +/- 0.017 h-1 for rat HDL ester and ether respectively. Biological screening of the rat HDL preparations did not affect these differences. The results of these studies indicate that in the absence of plasma CETA, cholesteryl ethers can be used to trace LDL cholesteryl esters but not to trace HDL cholesteryl esters.

  20. Stereodivergent Olefination of Enantioenriched Boronic Esters

    PubMed Central

    Armstrong, Roly J.; García‐Ruiz, Cristina; Myers, Eddie L.

    2016-01-01

    Abstract A stereodivergent coupling reaction between vinyl halides and boronic esters is described. This coupling process proceeds without a transition‐metal catalyst, instead proceeding by electrophilic selenation or iodination of a vinyl boronate complex followed by stereospecific syn or anti elimination. Chiral, nonracemic boronic esters could be coupled with complete enantiospecificity. The process enables the highly stereoselective synthesis of either the E or Z alkene from a single isomer of a vinyl coupling partner. PMID:27958668

  1. New daucane esters from Ferula tingitana.

    PubMed

    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.

  2. Synthesis of a new energetic nitrate ester

    SciTech Connect

    Chavez, David E

    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.

  3. 40 CFR 721.10664 - Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). 721.10664 Section 721.10664... Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). (a...

  4. Esters of valerenic acid as potential prodrugs

    PubMed Central

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

    2014-01-01

    Valerenic acid (VA) is a β2/3 subunit-specific modulator of γ-aminobutyric acid (GABA) type A (GABAA) receptors inducing anxiolysis. Here we analyze if VA-esters can serve as prodrugs and if different ester structures have different in vitro/in vivo effects. Modulation of GABAA receptors expressed in Xenopus oocytes was studied with 2-microelectrode-voltage-clamp. Anxiolytic effects of the VA-esters were studied on male C57BL/6N mice by means of the elevated plus maze-test; anticonvulsant properties were deduced from changes in seizure threshold upon pentylenetetrazole infusion. VA was detected in plasma confirming hydrolysis of the esters and release of VA in vivo. Esterification significantly reduced the positive allosteric modulation of GABAA (α1β3γ2S) receptors in vitro. in vivo, the studied VA-ester derivatives induced similar or even stronger anxiolytic and anticonvulsant action than VA. While methylation and propylation of VA resulted in faster onset of anxiolysis, the action of VA-ethylester was longer lasting, but occurred with a significant delay. The later finding is in line with the longer lasting anticonvulsant effects of this compound. The estimated VA plasma concentrations provided first insight into the release kinetics from different VA-esters. This might be an important step for its future clinical application as a potential non-sedative anxiolytic and anticonvulsant. PMID:24680924

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

    PubMed Central

    Wang, Chongnian; Li, Zengchang

    2015-01-01

    Summary 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. PMID:25815072

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

    USDA-ARS?s Scientific Manuscript database

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

  7. Detection of testosterone esters in blood.

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1999-06-01

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

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

    PubMed

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

    2010-03-01

    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.

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

    PubMed Central

    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

  11. Xanthophyll esters are found in human colostrum.

    PubMed

    Ríos, José J; Xavier, Ana Augusta Odorissi; Díaz-Salido, Elena; Arenilla-Vélez, Isabel; Jarén-Galán, Manuel; Garrido-Fernández, Juan; Aguayo-Maldonado, Josefa; Pérez-Gálvez, Antonio

    2017-06-06

    Carotenoids in human milk are associated with other lipid counterparts in several metabolic processes. One interesting association that has not been demonstrated to date is the presence of xanthophyll esters. Colostrum and mature milk samples were analyzed to determine the occurrence of xanthophyll esters and identify the compounds. Thus, the association of the amounts of these compounds with lactation and whether they are significant contributors to the carotenoid profile of human milk was assessed. Pre-term and term delivering mothers were included in the study to donate colostrum at 3-5 days postpartum and mature milk at 15 days postpartum. Carotenoids extracts were subjected to a clean-up procedure to remove the triacylglycerol fraction and then analyzed by HPLC-MS(n) . Identification of xanthophyll esters was achieved by considering their chromatographic behaviour, UV-visible characteristics and MS(n) features. Xanthophyll esters are significant contributors to the carotenoid profile in the colostrum, while mature milk does not contain these compounds. Therefore, fatty acid acylation to xanthophylls is activated during the accumulation of carotenoids in the human mammary gland. The sharp decline in the amount of xanthophyll esters in mature milk indicates that the lipophilic components are those recently incorporated in the mammary epithelium. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    PubMed

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

    PubMed

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

    2011-01-01

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

  14. Emission of sunscreen salicylic esters from desert vegetation and their contribution to aerosol formation

    NASA Astrophysics Data System (ADS)

    Matsunaga, S. N.; Guenther, A. B.; Potosnak, M. J.; Apel, E. C.

    2008-07-01

    Biogenic volatile organic compounds (BVOC) produced by plants are known to have an important role in atmospheric chemistry. However, our knowledge of the range of BVOCs produced by different plant processes is still expanding, and there remain poorly understood categories of BVOCs. In this study, emissions of a novel class of BVOC emissions were investigated in a desert region. Our study considered 8 species of common desert plants: blackbrush (Coleogyne ramosissima), desert willow (Chilopsis linearis), mesquite (Prosopis glandulosa), mondel pine (Pinus eldarica), pinyon pine (Pinus monophylla), cottonwood (Populus deltoides), saguaro cactus (Carnegiea gigantea) and yucca (Yucca baccata). The measurements focused on BVOCs with relatively high molecular weight (>C15) and/or an oxygenated functional group. Significantly high emission rates of two salicylic esters were found for blackbrush, desert willow and mesquite with emission rates of 1.4, 2.1 and 0.46 μgC dwg-1 h-1, respectively. The salicylic esters were identified as 2-ethylhexenyl salicylate (2-EHS) and 3,3,5-trimethylcyclohexenyl salicylate (homosalate) and are known as effective ultraviolet (UV) absorbers. We propose that the plants derive a protective benefit against UV radiation from the salicylic esters and that the emission process is driven by the physical evaporation of the salicylic esters due to the high ambient temperatures. In addition, the salicylic esters are predicted to be an effective precursor of secondary organic aerosol (SOA) because of their low vapor pressure due to a high number of carbon atoms (15 or 16) and the presence of three oxygen atoms. We estimated the contribution of the sunscreen esters themselves and their oxidation products on the SOA formation for the Las Vegas region using a BVOC emission model. The contribution was estimated to reach 90% of the biogenic SOA in the landscapes dominated by desert willow and mesquite and 25% in Las Vegas area.

  15. Emission of sunscreen salicylic esters from desert vegetation and their contribution to aerosol formation

    NASA Astrophysics Data System (ADS)

    Matsunaga, S. N.; Guenther, A. B.; Potosnak, M. J.; Apel, E. C.

    2008-12-01

    Biogenic volatile organic compounds (BVOC) produced by plants are known to have an important role in atmospheric chemistry. However, our knowledge of the range of BVOCs produced by different plant processes is still expanding, and there remain poorly understood categories of BVOCs. In this study, emissions of a novel class of BVOC emissions were investigated in a desert region. Our study considered 8 species of common desert plants: blackbrush (Coleogyne ramosissima), desert willow (Chilopsis linearis), mesquite (Prosopis glandulosa), mondel pine (Pinus eldarica), pinyon pine (Pinus monophylla), cottonwood (Populus deltoides), saguaro cactus (Carnegiea gigantea) and yucca (Yucca baccata). The measurements focused on BVOCs with relatively high molecular weight (>C15) and/or an oxygenated functional group. Significantly high emission rates of two salicylic esters were found for blackbrush, desert willow and mesquite with emission rates of 3.1, 1.0 and 4.8μgC dwg-1 h-1, respectively (dwg; dry weight of the leaves in gram). The salicylic esters were identified as 2-ethylhexenyl salicylate (2-EHS) and 3,3,5-trimethylcyclohexenyl salicylate (homosalate) and are known as effective ultraviolet (UV) absorbers. We propose that the plants derive a protective benefit against UV radiation from the salicylic esters and that the emission process is driven by the physical evaporation of the salicylic esters due to the high ambient temperatures. In addition, the salicylic esters are predicted to be an effective precursor of secondary organic aerosol (SOA) because they probably produce oxidation products that can condense onto the aerosol phase. We estimated the contribution of the sunscreen esters themselves and their oxidation products on the SOA formation for the Las Vegas area using a BVOC emission model. The contribution was estimated to reach 50% of the biogenic terpenoid emission in the landscapes dominated by desert willow and mesquite and 13% in the Las Vegas area. The

  16. Oxidative stability of DHA phenolic ester.

    PubMed

    Roby, Mohamed H H; De Castro, Vanessa C; Targino, Brenda N; Alves Da Silva, Paulo H; Mangavel, Cécile; Chretien, Françoise; Humeau, Catherine; Desobry, Stephane

    2015-02-15

    Docosahexaenoic acid vanillyl ester (DHA-VE) was synthesized from docosahexaenoic acid ethyl ester (DHA-EE) and vanillyl alcohol by a solvent-free alcoholysis process catalysed by Candida antarctica lipase B. Oxidative stability of pure DHA-VE and the crude reaction medium consisting of 45% DHA-VE and 55% DHA-EE were compared with that of DHA-EE under various storage conditions. Oxidation progress was followed by determination of conjugated dienes and FTIR measurements. Analyses showed that DHA-EE was rapidly oxidised under all storage conditions in comparison with DHA-VE and crude reaction medium, whatever the temperature and the storage time. The grafting of vanillyl alcohol appeared as a powerful way to stabilize DHA against oxidation. Thanks to their stability, both DHA-VE and the crude reaction medium, allowing the production of the ester, offer huge potential as functional ingredients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Glycerol esters as fuel economy additives

    SciTech Connect

    Brewster, P.W.; Smith, C.R.; Gowland, F.W.

    1987-07-28

    A lubricating oil composition formulated is described for use as a crankcase lubricating oil composition for gasoline or diesel engines consisting essentially of a major amount of a mineral oil of a lubricating viscosity which has incorporated about 0.20 weight percent of a glycerol partial ester. The partial ester is a mixture of glycerol monooleate and glycerol dioleate. The mixture has a weight ratio of 3 parts of glycerol monooleate to 2 parts of glycerol dioleate the ester providing a fuel economy improvement of about 1 to 3 percent when the lubricating oil composition is employed in the crankcase of the engine. An ashless dispersant, a metal detergent additive, a zinc dihdyrocarbyl dithiophosphate anti-wear additive and an antioxidant. The dispersant, detergent, anti-wear additive and antioxidant are present in conventional amounts to provide their normal attendant functions.

  18. Fate of dietary phytosteryl/-stanyl esters: analysis of individual intact esters in human feces.

    PubMed

    Lubinus, Tim; Barnsteiner, Andreas; Skurk, Thomas; Hauner, Hans; Engel, Karl-Heinz

    2013-04-01

    The objective was to investigate the metabolic fate of phytosteryl/-stanyl fatty acid and ferulic acid esters upon consumption by healthy humans. A capillary gas chromatographic methodology was employed to follow a randomized, single-blind three group crossover clinical trial and to quantify simultaneously individual intact esters, liberated phytosterols/-stanols and their metabolites in feces. Skimmed milk drinking yogurts enriched with complex mixtures of phytosteryl/-stanyl fatty acid esters and ferulates, respectively, were employed as food carriers. On average, 73 % of total plant stanyl fatty acid esters and 80 % of total plant steryl fatty acid esters were hydrolyzed. Among the individuals, the hydrolysis rates ranged from 40 to 96 %. In addition, there were subject-dependent discrepancies between the amounts of phytosterols/-stanols actually determined in the feces and the calculated hydrolysis rates. On average, 69 % of the amounts of sterols/stanols expected from the amounts of remaining intact esters were found. The study revealed large interindividual variability regarding the recoveries of dietary phytosteryl/-stanyl esters upon gastrointestinal passage in healthy humans. Nevertheless, there was a significant impact of the acid moiety (oleate=linoleate=linolenate>eicosanoate>palmitate>ferulate) on the hydrolysis rates; the influence of the phytosterol/-stanol moiety was less pronounced.

  19. Zero birefringence films of pullulan ester derivatives

    PubMed Central

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

    2017-01-01

    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. PMID:28417955

  20. Bis(o-trifluoromethylphenyl)dithiophosphinic Methyl Ester

    SciTech Connect

    John R. Klaehn; Dean R. Peterman; Mason K. Harrup; Thomas A. Luther; Lee M. Daniels

    2011-05-01

    When bis(o-trifluoromethylphenyl)dithiophosphinic acid (1) was dissolved in methanol, crystals of bis(o-trifluoromethylphenyl)dithiophosphinic methyl ester (2) were isolated. The structure of dithiophosphinic methyl ester (2) has been identified via single-crystal X-ray diffraction and multinuclear NMR studies. Compound 2 is remarkable in that the dithiophosphinic (PS2) core is preserved during this transformation. Many dithiophosphinic acids degrade to other compounds over time which results in formation of dithiophosphinic dimers, like the bis(dithiophosphinic) anhydride. The transformation to 2 suggests that the o-trifluoromethylphenyl groups on phosphorus assist in retaining the PS2 core, possibly by steric hindrance.

  1. Phthalate esters: Testing for ecological effects

    SciTech Connect

    Brown, D.; Thompson, R.; Croudace, C.; Stewart, K.; Williams, N.

    1995-12-31

    Ortho-phthalate esters are produced in high tonnages for use as plasticizers, in particular for PVC. Their physical chemical properties are typically very low water solubility and high octanol/water partition coefficient. This combination of properties presents a number of experimental difficulties in the design and interpretation of ecological effect studies. These difficulties are described and results presented showing techniques for the performance of reproduction studies with the water flea, Daphnia magna, in aqueous solution and with the midge, Chironomus riparius, in sediments. The results which showed no effect for the phthalate esters tested are discussed in the context of other ecotoxicity data obtained on these products.

  2. Pyrazolylcyclotriphosphazene containing pendant polymers: synthesis, characterization, and phosphate ester hydrolysis using a Cu(II)-metalated cross-linked polymeric catalyst.

    PubMed

    Chandrasekhar, Vadapalli; Athimoolam, Arunachalampillai; Srivatsan, S G; Sundaram, P Shanmuga; Verma, Sandeep; Steiner, Alexander; Zacchini, Stefano; Butcher, Raymond

    2002-10-07

    A multi-pyrazolyl cyclotriphosphazene containing polymerizable group N(3)P(3)(3,5-Me(2)Pz)(5)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2)) (2) has been prepared from the corresponding chloro derivative N(3)P(3)Cl(5)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2)) (1). The X-ray structures of 1 and 2 have been determined. Compound 2 undergoes ready metalation with CuCl(2) to afford N(3)P(3)(3,5-Me(2)Pz)(5)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2)).CuCl(2) (3). Model compound N(3)P(3)(3,5-Me(2)Pz)(5)(O-C(6)H(4)-p-CHO).CuCl(2) (6) has been prepared and characterized by spectroscopy and X-ray crystallography. In this compound, the coordination around copper is distorted trigonal bipyramidal, and the cyclotriphosphazene coordinates in a non-gem N(3) mode. Compound 2 has been copolymerized with divinylbenzene to afford cross-linked multisite coordinating polymer CPPL which is readily metalated with CuCl(2) to afford copper-containing polymer CPPL-Cu. The coordination environment around copper in CPPL-Cu has been evaluated by obtaining its EPR, optical, and IR spectra and comparing them with those of model compounds 3 and 6. The utility of CPPL-Cu as a heterogeneous catalyst has been demonstrated in the phosphate ester hydrolysis involving three model phosphate esters: p-nitrophenyl phosphate (pNPP), bis(p-nitrophenyl) phosphate (bNPP), and 2-(hydroxypropyl)-p-nitrophenyl phosphate (hNPP). In all of these reactions, a significant rate enhancement of ester hydrolysis is observed. Detailed kinetic analyses to evaluate Michaelis-Menten parameters have also been carried out along with experiments to elucidate the effect of pH, solvent, and temperature on the rate of hydrolysis. Recycling experiments on the hydrolysis of pNPP with CPPL-Cu shows that it can be recycled several times over without affecting the rates.

  3. Affinity labelling enzymes with esters of aromatic sulfonic acids

    DOEpatents

    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.

  4. 21 CFR 172.735 - Glycerol ester of rosin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....735 Glycerol ester of rosin. Glycerol ester of wood rosin, gum rosin, or tall oil rosin may be safely... or steam stripping. (b) It is used to adjust the density of citrus oils used in the preparation of...

  5. 21 CFR 172.735 - Glycerol ester of rosin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CONSUMPTION Other Specific Usage Additives § 172.735 Glycerol ester of rosin. Glycerol ester of wood rosin... purified by countercurrent steam distillation or steam stripping. (b) It is used to adjust the density of...

  6. 21 CFR 172.735 - Glycerol ester of rosin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CONSUMPTION Other Specific Usage Additives § 172.735 Glycerol ester of rosin. Glycerol ester of wood rosin... purified by countercurrent steam distillation or steam stripping. (b) It is used to adjust the density of...

  7. Novel Membrane Based Process for Producing Lactate Esters

    SciTech Connect

    1999-02-01

    Lactate Esters from Renewable Carbohydrate Feedstocks can Replace Petroleum-Derived Solvents. Lactate esters are versatile solvents that are biodegradable, nontoxic, and applicable to a wide range of industrial and consumer uses.

  8. Plant-mediated stereoselective biotransformation of phenylglyoxylic acid esters.

    PubMed

    Maczka, Wanda Krystyna; Grabarczyk, Małgorzata; Wińska, Katarzyna; Anioł, Mirosław

    2014-01-01

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

  9. Avocado and olive oil methyl esters

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Lipid encapsulated docosahexaenoic acid methyl ester

    USDA-ARS?s Scientific Manuscript database

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

  11. Oxidative stability of estolide esters using PDSC

    USDA-ARS?s Scientific Manuscript database

    Estolides are obtained by the formation of a carbocation that can undergo nucleophilic addition with or without carbocation migration along the length of the chain. The carboxylic acid functionality of one fatty acid links to the site of unsaturation of another fatty acid to form oligomeric esters. ...

  12. Total synthesis of zincophorin methyl ester.

    PubMed

    Defosseux, Magali; Blanchard, Nicolas; Meyer, Christophe; Cossy, Janine

    2003-10-30

    [reaction: see text]. A convergent total synthesis of the methyl ester of zincophorin, an ionophore antibiotic, has been realized relying on a diastereoselective titanium-mediated aldol coupling between the C1-C12 and C13-C25 subunits. The latter fragment was prepared by using a Carroll-Claisen rearrangement.

  13. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2805 Acrylate ester. Link to an amendment published at 79 FR 34637, June 18, 2014. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an...

  14. The MPEG monophosphate ester: synthesis and characterization.

    PubMed

    Penczek, Stanislaw; Kaluzynski, Krzysztof; Wisniewski, Blazej; Pretula, Julia; Szymanski, Ryszard; Lapienis, Grzegorz

    2009-01-01

    Methods of preparation of the phosphoric ester of monomethyl ether of poly(ethylene glycol) (MPEG-P) from MPEG (M(n) = 550 and 2000) and phosphoric acid (P), or its derivatives - pyrophosphoric acid (PY), polyphosphoric acid (PP) and POCl(3)- are described and compared. MPEG-P was isolated in a pure state (no detectable impurities) and characterized.

  15. CELLULOSE NITRATE-ACETATE MIXED ESTERS

    DTIC Science & Technology

    cellulose acetate . The degree of polymerization of the products, as estimated from viscosity data, shows the occurrence of chain degradation for both...mixed esters showed tensile strength at least comparable to that of films of cellulose nitrate or cellulose acetate . The impact sensitivity of the

  16. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 P-95-1128...

  17. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 section...

  18. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 P-97...

  19. 40 CFR 721.3085 - Brominated phthalate ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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) is...

  20. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 uses...

  1. 40 CFR 721.2121 - Thiosubstituted carbonate ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 new...

  2. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  3. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 this...

  4. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 the...

  5. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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. 21 CFR 172.735 - Glycerol ester of rosin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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 rosin...

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Lactylic esters of fatty acids. 172.848 Section... § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance with the following prescribed conditions: (a) They are prepared from lactic acid and fatty acids...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Lactylic esters of fatty acids. 172.848 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids may be safely used in food in accordance with the following prescribed conditions: (a) They...

  9. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 ester...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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 ester...

  11. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylic esters of fatty acids. 172.848 Section 172... CONSUMPTION Multipurpose Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids... prepared from lactic acid and fatty acids meeting the requirements of § 172.860(b) and/or oleic acid...

  12. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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 P-93-343...

  13. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  14. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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 ester...

  15. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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...

  16. 40 CFR 721.3110 - Polycarboxylic acid ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 ester...

  17. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  18. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 P-93-343...

  19. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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 P-93-343...

  20. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 P-93-343...

  1. 40 CFR 721.10431 - Phosphoric acid esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid esters (generic). 721... Substances § 721.10431 Phosphoric acid esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as phosphoric acid esters (PMNs P...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 P-97...

  3. 40 CFR 721.5310 - Neononanoic acid, ethenyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 P-92...

  4. 40 CFR 721.4215 - Hexanedioic acid, diethenyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 P-90...

  5. Synthesis and physical properties of new estolide esters

    USDA-ARS?s Scientific Manuscript database

    Estolides are a class of esters based on vegetable oils that, in this case, are formed when the carboxylic acid functionality of one fatty acid reacts at the site of unsaturation of another fatty acid to form an ester linkage. The objective of this preliminary study was to synthesize new esters of e...

  6. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyglycerol esters of fatty acids. 172.854... § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including..., safflower oil, sesame oil, soybean oil, and tallow and the fatty acids derived from these substances...

  7. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Code of Federal Regulations, 2010 CFR

    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 the...

  8. 40 CFR 721.3085 - Brominated phthalate ester.

    Code of Federal Regulations, 2010 CFR

    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) is...

  9. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Code of Federal Regulations, 2010 CFR

    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...

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

    Code of Federal Regulations, 2010 CFR

    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 ester...

  11. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2010 CFR

    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 uses...

  12. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  13. 40 CFR 721.1732 - Nitrobenzoic acid octyl ester.

    Code of Federal Regulations, 2010 CFR

    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 P-93-343...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  15. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2010 CFR

    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 P-95-1128...

  16. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2010 CFR

    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 section...

  17. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2010 CFR

    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 P-97...

  18. 40 CFR 721.2121 - Thiosubstituted carbonate ester (generic).

    Code of Federal Regulations, 2010 CFR

    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 new...

  19. 40 CFR 721.10685 - Phosphoric acid, mixed esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, mixed esters (generic... Specific Chemical Substances § 721.10685 Phosphoric acid, mixed esters (generic). (a) Chemical substance... phosphoric acid, mixed esters (PMN P-13-170) is subject to reporting under this section for the significant...

  20. 40 CFR 721.10431 - Phosphoric acid esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid esters (generic). 721... Substances § 721.10431 Phosphoric acid esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as phosphoric acid esters (PMNs P...

  1. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2010 CFR

    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...

  2. 40 CFR 721.3085 - Brominated phthalate ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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)...

  3. 40 CFR 721.10305 - Modified cyclohexane esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified cyclohexane esters (generic... Specific Chemical Substances § 721.10305 Modified cyclohexane esters (generic). (a) Chemical substance and... cyclohexane esters (PMN P-00-1108) is subject to reporting under this section for the significant new...

  4. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  5. 40 CFR 721.3085 - Brominated phthalate ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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)...

  6. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  7. 40 CFR 721.2121 - Thiosubstituted carbonate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  8. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  9. 40 CFR 721.10560 - Alkanoldioic dialkyl esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkanoldioic dialkyl esters (generic... Specific Chemical Substances § 721.10560 Alkanoldioic dialkyl esters (generic). (a) Chemical substance and... dialkyl esters (PMNs P-07-143 and P-07-144) are subject to reporting under this section for...

  10. 40 CFR 721.10715 - Carbonic acid, dialkyl ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Carbonic acid, dialkyl ester (generic... Specific Chemical Substances § 721.10715 Carbonic acid, dialkyl ester (generic). (a) Chemical substance and..., dialkyl ester (PMN P-13-346) is subject to reporting under this section for the significant new...

  11. 40 CFR 721.10323 - Glycerol fatty acid ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Glycerol fatty acid ester (generic... Specific Chemical Substances § 721.10323 Glycerol fatty acid ester (generic). (a) Chemical substance and... acid ester (PMN P-03-248) is subject to reporting under this section for the significant new...

  12. 40 CFR 721.10438 - Dialkyl hydroxybenzenealkanoic acid ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ester (generic). 721.10438 Section 721.10438 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10438 Dialkyl hydroxybenzenealkanoic acid ester (generic). (a) Chemical... as dialkyl hydroxybenzenealkanoic acid ester (PMN P-00-346) is subject to reporting under...

  13. 40 CFR 721.10314 - Dialkyl dithiocarbamate esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Dialkyl dithiocarbamate esters... Specific Chemical Substances § 721.10314 Dialkyl dithiocarbamate esters (generic). (a) Chemical substance... dialkyl dithiocarbamate esters (PMNs P-02-778, P-02-779, and P-02-780) are subject to reporting under...

  14. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  15. 40 CFR 721.10255 - Vinyl carboxylic acid ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Vinyl carboxylic acid ester (generic... Specific Chemical Substances § 721.10255 Vinyl carboxylic acid ester (generic). (a) Chemical substance and... carboxylic acid ester (PMN P-09-400) is subject to reporting under this section for the significant new...

  16. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  17. 40 CFR 721.4158 - Hexadecanoic acid, ethenyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  18. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  19. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  20. 40 CFR 721.10560 - Alkanoldioic dialkyl esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkanoldioic dialkyl esters (generic... Specific Chemical Substances § 721.10560 Alkanoldioic dialkyl esters (generic). (a) Chemical substance and... dialkyl esters (PMNs P-07-143 and P-07-144) are subject to reporting under this section for...

  1. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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. 40 CFR 721.3140 - Vinyl epoxy ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  4. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  5. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  6. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  7. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  8. 40 CFR 721.10305 - Modified cyclohexane esters (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified cyclohexane esters (generic... Specific Chemical Substances § 721.10305 Modified cyclohexane esters (generic). (a) Chemical substance and... cyclohexane esters (PMN P-00-1108) is subject to reporting under this section for the significant new...

  9. 40 CFR 721.10323 - Glycerol fatty acid ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Glycerol fatty acid ester (generic... Specific Chemical Substances § 721.10323 Glycerol fatty acid ester (generic). (a) Chemical substance and... acid ester (PMN P-03-248) is subject to reporting under this section for the significant new...

  10. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  11. 40 CFR 721.10305 - Modified cyclohexane esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified cyclohexane esters (generic... Specific Chemical Substances § 721.10305 Modified cyclohexane esters (generic). (a) Chemical substance and... cyclohexane esters (PMN P-00-1108) is subject to reporting under this section for the significant new...

  12. 40 CFR 721.10314 - Dialkyl dithiocarbamate esters (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Dialkyl dithiocarbamate esters... Specific Chemical Substances § 721.10314 Dialkyl dithiocarbamate esters (generic). (a) Chemical substance... dialkyl dithiocarbamate esters (PMNs P-02-778, P-02-779, and P-02-780) are subject to reporting under...

  13. 40 CFR 721.10255 - Vinyl carboxylic acid ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Vinyl carboxylic acid ester (generic... Specific Chemical Substances § 721.10255 Vinyl carboxylic acid ester (generic). (a) Chemical substance and... carboxylic acid ester (PMN P-09-400) is subject to reporting under this section for the significant new...

  14. 40 CFR 721.10323 - Glycerol fatty acid ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Glycerol fatty acid ester (generic... Specific Chemical Substances § 721.10323 Glycerol fatty acid ester (generic). (a) Chemical substance and... acid ester (PMN P-03-248) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.10477 - Acrylate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylate ester (generic). 721.10477... Substances § 721.10477 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-04-290) is subject...

  16. 40 CFR 721.10314 - Dialkyl dithiocarbamate esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Dialkyl dithiocarbamate esters... Specific Chemical Substances § 721.10314 Dialkyl dithiocarbamate esters (generic). (a) Chemical substance... dialkyl dithiocarbamate esters (PMNs P-02-778, P-02-779, and P-02-780) are subject to reporting under...

  17. 40 CFR 721.10477 - Acrylate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate ester (generic). 721.10477... Substances § 721.10477 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-04-290) is subject...

  18. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... HUMAN CONSUMPTION Multipurpose Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters...

  19. 40 CFR 721.10255 - Vinyl carboxylic acid ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Vinyl carboxylic acid ester (generic... Specific Chemical Substances § 721.10255 Vinyl carboxylic acid ester (generic). (a) Chemical substance and... carboxylic acid ester (PMN P-09-400) is subject to reporting under this section for the significant new...

  20. 40 CFR 721.10537 - Acrylate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylate ester (generic). 721.10537... Substances § 721.10537 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-01-579) is subject...

  1. 40 CFR 721.2121 - Thiosubstituted carbonate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  2. 40 CFR 721.3085 - Brominated phthalate ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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)...

  3. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Lactylic esters of fatty acids. 172.848 Section 172.848 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... HUMAN CONSUMPTION Multipurpose Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters...

  4. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  5. 40 CFR 721.10438 - Dialkyl hydroxybenzenealkanoic acid ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ester (generic). 721.10438 Section 721.10438 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10438 Dialkyl hydroxybenzenealkanoic acid ester (generic). (a) Chemical... as dialkyl hydroxybenzenealkanoic acid ester (PMN P-00-346) is subject to reporting under...

  6. 40 CFR 721.10537 - Acrylate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate ester (generic). 721.10537... Substances § 721.10537 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-01-579) is subject...

  7. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  8. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  9. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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 ester...

  10. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2010 CFR

    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 ester...

  11. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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 ester...

  12. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 ester...

  13. 40 CFR 721.3080 - Substituted phosphate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 ester...

  14. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis

    NASA Technical Reports Server (NTRS)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of catonic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrogen hydrolysis rate constant.

  15. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis

    NASA Technical Reports Server (NTRS)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of catonic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrogen hydrolysis rate constant.

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

    PubMed

    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.

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

    PubMed

    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.

  18. Flavor-active esters: adding fruitiness to beer.

    PubMed

    Verstrepen, Kevin J; Derdelinckx, Guy; Dufour, Jean-Pierre; Winderickx, Joris; Thevelein, Johan M; Pretorius, Isak S; Delvaux, Freddy R

    2003-01-01

    As they are responsible for the fruity character of fermented beverages, volatile esters constitute an important group of aromatic compounds in beer. In modern high-gravity fermentations, which are performed in tall cylindroconical vessels, the beer ester balance is often sub-optimal, resulting in a clear decrease in beer quality. Despite the intensive research aimed at unravelling the precise mechanism and regulation of ester synthesis, our current knowledge remains far from complete. However, a number of factors that influence flavor-active ester production have already been described, including wort composition, wort aeration and fermentor design. A thoughtful adaptation of these parameters allows brewers to steer ester concentrations and thus to control the fruity character of their beers. This paper reviews the current knowledge of the biochemistry behind yeast ester synthesis and discusses the different factors that allow ester formation to be controlled during brewery fermentation.

  19. 4-Hydroxy-3-methoxycinnamate esters of milkweed oil: synthesis and characterization.

    PubMed

    Harry-O'kuru, Rogers E

    2005-11-01

    The common milkweed (Asclepias syriaca L.) is a new industrial crop. Its seed oil (TAG) is highly polyunsaturated. In the search for novel applications for milkweed seed oil, the olefinic groups in the TAG were oxidized to polyhydroxy TAG via epoxidation and subsequent epoxy ring-opening reactions. These polyhydroxy TAG exhibit unique industrially desirable emulsoid properties in water. Esterification of the secondary polyhydroxy functionalities of the TAG derivatives of the oil with trans-4-hydroxy-3-methoxycinnamic acid (ferulic acid) has resulted in the development of novel cinnamate esters of milkweed oil. These cinnamates are also obtainable via direct ring-opening of the epoxy TAG intermediate with ferulic acid. Among the interesting characteristics of the ester derivatives is their UV radiation-absorbing property.

  20. Caffeic Acid Phenethyl Ester and Therapeutic Potentials

    PubMed Central

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

    2014-01-01

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

  1. Withanolides and Sucrose Esters from Physalis neomexicana.

    PubMed

    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.

  2. One new triterpene ester from Nepeta suavis.

    PubMed

    Hussain, Javid; Khan, Farman Ullah; Ur Rehman, Najeeb; Ullah, Riaz; Mohmmad, Zia; Tasleem, S; Naeem, A; Shah, M Raza

    2009-12-01

    One new tetracyclic triterpene ester (1) has been isolated from the chloroform-soluble portion of the whole plant of Nepeta suavis along with two known compounds, namely artemetin (2) and jaceidin (3). The structures of the isolated compounds were assigned on the basis of their (1)H and (13)C NMR spectra including two-dimensional NMR techniques such as COSY, HMQC, and HMBC experiments and comparison with the literature data.

  3. Determination of phthalate esters in human semen.

    PubMed

    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.

  4. Bacteriopheophorbide esters: photosensitizers without "threshold dose"?

    NASA Astrophysics Data System (ADS)

    Moser, Joerg G.; Ostrowsky, Andreas; Guemuesdagli, Maria; Kleiber, Beate

    1994-03-01

    Uptake and phototoxicity of the methyl-, ethyl-, n-propyl, and 2-propyl esters of 132- hydroxy bacteriopheophorbide a were studied in OAT 75 SCLC cells and 3 different amelanotic melanoma cell lines. (A 375, Melur SP 18, SkAMel 25). Specific phototoxicity did not substantially differ for the different esters. Most surprisingly, these photosensitizers did not show any significant threshold behavior: even at 25 (mu) W/cm2 (775 nm, diode laser) cancer cell suspensions were killed in a time-dependent logarithmic fashion. Furthermore, phototoxicity is enhanced at low power densities if compared with the effects at 1 - 10 mW/cm2. This can be related only in part to a lack of oxygen at higher power densities. Complementary experiments confirmed that threshold is power but not dose dependent. Thus, threshold power density should be included into a prospective list of criteria characterizing photosensitizers suitable for photodynamic cancer therapy. The obvious lack of a limiting power density in bacteriopheophobide a esters make these sensitizers a prospective tool for tumor therapy in considerable tissue depth.

  5. Calorimetric study of peroxycarboxylic ester synthesis.

    PubMed

    Fritzsche, L; Knorr, A

    2009-04-30

    Exothermic reactions involving organic peroxides carry a high potential hazard and must be considered with care. A safe handling requires, among others, the assessment of thermal process safety, for which safety characteristics like overall heat production and the resulting adiabatic temperature rise are essential. The article presents the results of the calorimetric investigation of the synthesis of four peroxycarboxylic esters, three tert-Butyl and one tert-Amyl peroxycarboxylic ester. In the two-step synthesis the second one clearly shows the higher exothermic potential. The overall heat production lies in the range of 126-135 kJ/mol and is nearly independent of the carboxylic acid residual in the tert-Butyl peroxycarboxylic ester. The calculated adiabatic temperature rise is 70-80K. Influence of temperature and feed rate on the heat generation is discussed for one species. A grading of the synthesis with respect to temperature levels according to the criticality classes by Stoessel leads to the most critical for an exothermic reaction.

  6. Determination of testosterone esters and nortestosterone esters in animal blood serum by LC-MS/MS.

    PubMed

    Rejtharová, Martina; Rejthar, Libor; Čačková, Katarína

    2017-10-05

    A sensitive and robust confirmatory method for determination of steroid esters in blood serum is essential for reliable monitoring of possible illegal use of steroid hormones as growth promoters in meat production. A previously used sample preparation methodology was improved. The procedure consists of protein precipitation and removal of phospholipids by dispersive SPE Supel(TM) QuE Z-Sep (Sigma-Aldrich) followed by clean-up on alumina column and LC-MS/MS measurement. The modified method has been validated according to Commission Decision 2002/657/EC. Validation parameters for determination of six testosterone esters and five nortestosterone esters in bovine and porcine blood serum are presented in this manuscript. Decision limits for all analytes were observed in the range 10 - 20 pg mL(-1). The method described in this manuscript is considerably robust for bovine and porcine serum analyses and can be applied both for screening and confirmatory determination in routine residue monitoring.

  7. Radiation Protection

    MedlinePlus

    ... EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us Radiation Protection Document Library View and download EPA radiation ...

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

    USGS Publications Warehouse

    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.

  9. Design, Synthesis and Study of Catalysts for Organophosphate Ester Hydrolysis.

    DTIC Science & Technology

    1985-07-01

    catalysts for phosphate ester hydrolyses which are modelled after carbonic anhydrase (CA) and alkaline phosphatase (APase). Section II describes the...Catalysts for Hydrolysis of Phosphate Esters. Alkaline phosphatases (APases) are Zn(II)- and Mg(II)- containing metalloenzymes found in virtually every...E TA "APR 14 07 k-1 le -p /m mm Alkaline phosphatase , models, catalysis, organophosphate ester, hydrolysis, metal ion 2"n.VUAC? - ",N-060 p MV ad& N

  10. Parameters Affecting Ethyl Ester Production by Saccharomyces cerevisiae during Fermentation▿

    PubMed Central

    Saerens, S. M. G.; Delvaux, F.; Verstrepen, K. J.; Van Dijck, P.; Thevelein, J. M.; Delvaux, F. R.

    2008-01-01

    Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of unsaturated fatty acids in the fermentation medium resulted in a general decrease in ethyl ester production. On the other hand, a higher fermentation temperature resulted in greater ethyl octanoate and decanoate production, while a higher carbon or nitrogen content of the fermentation medium resulted in only moderate changes in ethyl ester production. Analysis of the expression of the ethyl ester biosynthesis genes EEB1 and EHT1 after addition of medium-chain fatty acid precursors suggested that the expression level is not the limiting factor for ethyl ester production, as opposed to acetate ester production. Together with the previous demonstration that provision of medium-chain fatty acids, which are the substrates for ethyl ester formation, to the fermentation medium causes a strong increase in the formation of the corresponding ethyl esters, this result further supports the hypothesis that precursor availability has an important role in ethyl ester production. We concluded that, at least in our fermentation conditions and with our yeast strain, the fatty acid precursor level rather than the activity of the biosynthetic enzymes is the major limiting factor for ethyl ester production. The expression level and activity of the fatty acid biosynthetic enzymes therefore appear to be prime targets for flavor modification by alteration of process parameters or through strain selection. PMID:17993562

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

    PubMed

    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.

  12. Chemical and physical analyses of wax ester properties

    PubMed Central

    Patel, Sejal; Nelson, Dennis R.; Gibbs, Allen G.

    2001-01-01

    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. PMID:15455064

  13. Chemical and physical analyses of wax ester properties.

    PubMed

    Patel, S; Nelson, D R; Gibbs, A G

    2001-01-01

    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, T(m), of >60 synthetic wax esters, containing 26-48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38-73 degrees C. The main factor affecting T(m) was the total chain length of the wax ester, but the placement of the ester bond also affected T(m). Insertion of a double bond into either the alcohol or acid moiety decreased T(m) by approximately 30 degrees C. Simple mixtures of wax esters with n-alkanes melted several degrees 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 degrees C below primary esters of the same molecular weight and reduced T(m) of the total surface lipids to environmental values.

  14. Radiation sickness

    MedlinePlus

    ... to determine the amount of radiation exposure from nuclear accidents, the best signs of the severity of the ... doses of radiation, such as radiation from a nuclear power plant accident Exposure to excessive radiation for medical treatments

  15. Radiation enteritis

    MedlinePlus

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  16. Bioactive caffeic acid esters from Glycyrrhiza glabra.

    PubMed

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

    2009-01-01

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

  17. Structural studies of acyl esters of entacapone

    NASA Astrophysics Data System (ADS)

    Leppänen, J.; Wegelius, E.; Nevalainen, T.; Järvinen, T.; Gynther, J.; Huuskonen, J.

    2001-05-01

    The crystal structures of entacapone [( E)-2-cyano- N, N-diethyl-3-(3,4-dihydroxy-5-nitrophenyl)propenamide] and three of its acyl esters were solved. Entacapone, and its monopivaloate and diacetate derivatives, exist in the E-form while its dibenzoate derivative adopts the Z-form in the crystalline state. The ethyl substituents of the E-form are not freely rotating, as demonstrated by the broad signals in the 1H and 13C NMR spectra. The rotation barrier for the E-form was defined by the crystal structures, which show that free rotation of the ethyl substituents is blocked by the cyano-group.

  18. Specific binding of phorbol ester tumor promoters

    PubMed Central

    Driedger, Paul E.; Blumberg, Peter M.

    1980-01-01

    [20-3H]Phorbol 12,13-dibutyrate bound to particulate preparations from chicken embryo fibroblasts in a specific, saturable, reversible fashion. Equilibrium binding occurred with a Kd of 25 nM; this value is very close to the 50% effective dose (ED50), 50 nM, previously determined for the biological response (induction of fibronectin loss) in growing chicken embryo fibroblasts. At saturation, 1.4 pmol of [20-3H]phorbol 12,13-dibutyrate was bound per mg of protein (approximately 7 × 104 molecules per cell). Binding was inhibited by phorbol 12-myristate 13-acetate (Ki = 2 nM), mezerein (Ki = 180 nM), phorbol 12,13-dibenzoate (Ki = 180 nM), phorbol 12,13-diacetate (Ki = 1.7 μM), phorbol 12,13,20-triacetate (Ki = 39 μM), and phorbol 13-acetate (Ki = 120 μM). The measured Ki values are all within a factor of 3.5 of the ED50 values of these derivatives for inducing loss of fibronectin in intact cells. Binding was not inhibited by the inactive compounds phorbol (10 μg/ml) and 4α-phorbol 12,13-didecanoate (10 μg/ml) or by the inflammatory but nonpromoting phorbol-related diterpene esters resiniferatoxin (100 ng/ml) and 12-deoxyphorbol 13-isobutyrate 20-acetate (100 ng/ml). These data suggest that biological responses to the phorbol esters in chicken embryo fibroblasts are mediated by this binding activity and that the binding activity corresponds to the phorbol ester target in mouse skin involved in tumor promotion. Binding was not inhibited by the nonphorbol promoters anthralin (1 μM), phenol (1 mM), iodoacetic acid (1.7 μM), and cantharidin (75 μM), or by epidermal growth factor (100 ng/ml), dexamethasone acetate (2 μM), retinoic acid (10 μM), or prostaglandin E2 (1 μM). These agents thus appear to act at a target distinct from that of the phorbol esters. PMID:6965793

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

    PubMed

    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.

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

    USDA-ARS?s Scientific Manuscript database

    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. Radiation dosimetry.

    PubMed Central

    Cameron, J

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists. PMID:2040250

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

    PubMed

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

    1984-03-01

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

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

    PubMed Central

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

    2010-01-01

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

  4. Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

    NASA Technical Reports Server (NTRS)

    Keefe, Anthony D.; Miller, Stanley L.

    1995-01-01

    It is widely held that there was a phosphate compound in prebiotic chemistry that played the role of adenosine triphosphate and that the first living organisms had ribose-phosphate in the backbone of their genetic material. However, there are no known efficient prebiotic synthesis of high-energy phosphates or phosphate esters. We review the occurrence of phosphates in nature, the efficiency of the volcanic synthesis of P4O10, the efficiency of polyphosphate synthesis by heating phosphate minerals under geological conditions, and the use of high-energy organic compounds such as cyanamide or hydrogen cyanide. These are shown to be inefficient processes especially when the hydrolysis of the polyphosphates is taken into account. For example, if a whole atmosphere of methane or carbon monoxide were converted to cyanide which somehow synthesized polyphosphates quantitatively, the polyphosphate concentration in the ocean would still have been insignificant. We also attempted to find more efficient high-energy polymerizing agents by spark discharge syntheses, but without success. There may still be undiscovered robust prebiotic syntheses of polyphosphates, or mechanisms for concentrating them, but we conclude that phosphate esters may not have been constituents of the first genetic material. Phosphoanhydrides are also unlikely as prebiotic energy sources.

  5. Sucrose ester nanodispersions: microviscosity and viscoelastic properties.

    PubMed

    Ullrich, Sebastian; Metz, Hendrik; Mäder, Karsten

    2008-10-01

    Sucrose esters have the potential to enhance both drug solubility and drug absorption. They are therefore alternatives to the widely used glycerides in the formulation of lipid-based drug delivery systems. A simple production of aqueous nanosized drug carrier systems consisting of amphiphilic sucrose fatty acid esters using exclusively nontoxic materials has been achieved. By only using 2 wt% of the emulsifier a high viscosity of the sample could be reached. Diverse history of fabrication led to the differences in the macroviscosity of SE dispersions with equal chemical composition. Combining the well-established oscillating rheology with the electron paramagnetic resonance technique, three orders of magnitude difference in macroviscosity between the dispersions containing 2 wt% of the amphiphilic SE were obtained, whereas the viscosities at the molecular level were all close to the viscosity of water. Viscoelastic behaviour could also be shown for these systems. TEM experiments visualized coexisting irregular micelles and lamellar structures in the SE dispersions. The results are important to understand the complex LDDS based on amphiphilic SE.

  6. 40 CFR 721.10448 - Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ester, reaction products with substituted alkylamine (generic). 721.10448 Section 721.10448 Protection... Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine (generic). (a... generically as acetic acid, hydroxymethoxy-, methyl ester, reaction products with substituted alkylamine...

  7. 40 CFR 721.10309 - Ethoxylated, propoxylated diamine diaryl substituted phenylmethane ester with alkenylsuccinate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diaryl substituted phenylmethane ester with alkenylsuccinate (generic). 721.10309 Section 721.10309... Ethoxylated, propoxylated diamine diaryl substituted phenylmethane ester with alkenylsuccinate (generic). (a... generically as ethoxylated, propoxylated diamine diaryl substituted phenylmethane ester with...

  8. A lipid-coated lipase as an enantioselective ester synthesis catalyst in homogeneous organic solvents

    SciTech Connect

    Okahata, Yoshio; Fujimoto, Yoshitaka; Ijiro, Kuniharu

    1995-04-07

    The authors studied the enantioselective preparation of esters using lipase as catalyst. The surface of the lipase was coated with lipids to assist in directing the formation of the ester by solubilizing the hydrophobic incipient tail of the ester.

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

    ERIC Educational Resources Information Center

    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…

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

    DOEpatents

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

    1998-09-15

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

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

    DOEpatents

    Gogate, Makarand Ratnakar; Spivey, James Jerry; Zoeller, Joseph Robert

    1998-01-01

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

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

    SciTech Connect

    Yao, Linxing; Hammond, Earl G; Wang, Tong; Bu, Wei; Vaknin, David

    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. Improved preparation of haloalkyl bridged carboxylic ortho esters

    USDA-ARS?s Scientific Manuscript database

    Protection of a carboxylic acid function as a bridged ortho ester derivative enables the use of strong basic conditions in the synthetic strategy. For example, a protected 3-halopropionic acid can behave like an alkyl halide because the protons, alpha to the halide function, are less acidic. Ester...

  14. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... approved emulsifiers in dry, whipped topping base. The fatty acids used in the production of the... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyglycerol esters of fatty acids. 172.854... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol...

  15. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... approved emulsifiers in dry, whipped topping base. The fatty acids used in the production of the... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyglycerol esters of fatty acids. 172.854... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol...

  16. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... approved emulsifiers in dry, whipped topping base. The fatty acids used in the production of the... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyglycerol esters of fatty acids. 172.854... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol...

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

    PubMed

    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.

  18. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  19. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  20. Engineering modular ester fermentative pathways in Escherichia coli.

    PubMed

    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.

  1. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  2. 40 CFR 721.8660 - Propionic acid methyl ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

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

    ERIC Educational Resources Information Center

    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…

  4. Meltable dextran esters as biocompatible and functional coating materials.

    PubMed

    Liebert, Tim; Wotschadlo, Jana; Laudeley, Peggy; Heinze, Thomas

    2011-08-08

    The conversion of dextran with in situ synthesized iminium chlorides of long chain carboxylic acids was used to obtain pure and defined melting dextran esters in an efficient one-pot synthesis. The melting point of these esters can be tailored by the degree of substitutions (DS), the molecular weight of the starting polymer, and the chain length of the ester moiety. The dextran esters give homogeneous and completely transparent melts, which form stable films on a broad variety of materials. Even complex geometries, such as implants, can be evenly coated by multiple melting steps. The films do not display any inhomogeneity and have a very low surface roughness. Therefore, no unspecific protein binding is observed. Moreover, the dextran esters are biocompatible as demonstrated for the interaction with three types of cells namely human brain microvascular endothelial cell, primary human fibroblasts, and mouse myoblast cells.

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

    DOEpatents

    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.

  6. Use of bis-(chiral alpha-methylbenzyl)glycine esters for synthesis of enantiopure beta-hydroxyamino esters.

    PubMed

    Yamashita, Ayako; Norton, Emily B; Williamson, R Thomas; Ho, Douglas M; Sinishtaj, Sandra; Mansour, Tarek S

    2003-09-04

    [reaction: see text] Aldol reactions using bis-(chiral alpha-methylbenzyl)glycine esters with aldehydes gave excellent diastereoselectivity. Thus, an enantiopure ribosylglycine was prepared for the synthesis of analogues of the natural antibiotics muraymycin. This method was extended for formation of beta-hydroxyamino esters.

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

    PubMed

    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.

  8. Cholesteryl esters in human malignant neoplasms.

    PubMed

    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.

  9. Phosphorylation of Kraft fibers with phosphate esters.

    PubMed

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

    2014-06-15

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

  10. Transition-metal-mediated thiosulfinate ester synthesis

    SciTech Connect

    Raseta, M.E.; Cawood, S.A.; Welker, M.E. ); Rheingold, A.L. )

    1989-10-11

    Unlike sulfur dioxide (SO{sub 2}), the coordination and organic reaction chemistry of disulfur monoxide (S{sub 2}O) has received little attention. A few Diels-Alder reactions of simple dienes with S{sub 2}O have been reported. However, there were no reports of direct S{sub 2}O complex synthesis prior to our initial work. The authors recently published a synthesis of 4,5-diphenyl-3,6-dihydro-1,2-dithiin 1-oxide (2) which liberates S{sub 2}O via a transition-metal-assisted retro-Diels-Alder reaction. Here we report further on the unusual reactivity of 2 and its utilization in the synthesis of cyclic thiosulfinate esters.

  11. Cognitive effects of creatine ethyl ester supplementation.

    PubMed

    Ling, Jonathan; Kritikos, Minos; Tiplady, Brian

    2009-12-01

    Supplementation with creatine-based substances as a means of enhancing athletic performance has become widespread. Until recently, however, the effects of creatine supplementation on cognitive performance has been given little attention. This study used a new form of creatine--creatine ethyl ester--to investigate whether supplementation would improve performance in five cognitive tasks, using a double-blind, placebo-controlled study. Creatine dosing led to an improvement over the placebo condition on several measures. Although creatine seems to facilitate cognition on some tasks, these results require replication using objective measures of compliance. The improvement is discussed in the context of research examining the influence of brain energy capacity on cognitive performance.

  12. Ketone ester effects on metabolism and transcription.

    PubMed

    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.

  13. Ketone ester effects on metabolism and transcription

    PubMed Central

    Veech, Richard L.

    2014-01-01

    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. PMID:24714648

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

    PubMed

    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.

  15. Radiation Therapy

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Radiation Therapy KidsHealth > For Teens > Radiation Therapy Print A ... how to cope with side effects. What Is Radiation Therapy? Cancer is a disease that causes cells ...

  16. Radiation Therapy

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Radiation Therapy KidsHealth > For Teens > Radiation Therapy A A ... how to cope with side effects. What Is Radiation Therapy? Cancer is a disease that causes cells ...

  17. Radiation Therapy

    MedlinePlus

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

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

    PubMed

    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.

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

    PubMed

    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).

  20. Radiation exchange

    SciTech Connect

    Taylor, J.H. )

    1990-01-01

    This book deals with radiation laws, the phenomena of radiation exchange, the quantification of radiation, and the mechanisms whereby radiation is attenuated in passing through the earth's atmosphere. Applications of radiation exchange are discussed, such as the measurement of the effective radiating temperature of the ozonosphere. Also presented is the development of the concept of atmospheric windows and atmospheric transmittance. Radiation exchange experiments between Earth and space are presented and their interpretations given. The book fives detailed, step-by-step procedures for carrying out the radiometric calibration of an infrared prism spectrometer and a radiation thermopile.

  1. Atmospheric radiation

    SciTech Connect

    Harshvardhan, M.R. )

    1991-01-01

    Studies of atmospheric radiative processes are summarized for the period 1987-1990. Topics discussed include radiation modeling; clouds and radiation; radiative effects in dynamics and climate; radiation budget and aerosol effects; and gaseous absorption, particulate scattering and surface reflection. It is concluded that the key developments of the period are a defining of the radiative forcing to the climate system by trace gases and clouds, the recognition that cloud microphysics and morphology need to be incorporated not only into radiation models but also climate models, and the isolation of a few important unsolved theoretical problems in atmospheric radiation.

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

    PubMed

    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.

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

    PubMed

    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.

  4. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  5. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  6. Synthesis and low temperature characterization of iso-oleic ester derivatives

    USDA-ARS?s Scientific Manuscript database

    Three new iso-oleic ester derivatives (i.e., isopropyl esters (IOA-iPrE), n-butyl esters (IOA-n-BuE), and 2-ethylhexyl esters (IOA-2-EHE)) were synthesized from iso-oleic acid (IOA) using a standard esterification method. These esterified alcohols were chosen because of their bulky and branched-cha...

  7. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2010 CFR

    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...

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

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

    Code of Federal Regulations, 2010 CFR

    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...

  10. 21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  11. 21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  12. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  13. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  14. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  15. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  16. 21 CFR 184.1101 - Diacetyl tartaric acid esters of mono- and diglycerides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Glyceryl-lacto esters of fatty acids. 172.852... § 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 accordance with the following...

  18. Pelvic radiation - discharge

    MedlinePlus

    Radiation of the pelvis - discharge; Cancer treatment - pelvic radiation; Prostate cancer - pelvic radiation; Ovarian cancer - pelvic radiation; Cervical cancer - pelvic radiation; Uterine cancer - pelvic radiation; Rectal cancer - ...

  19. Analysis of phosphate esters in plant material

    PubMed Central

    Isherwood, F. A.; Barrett, F. C.

    1967-01-01

    1. A critical study was made of the quantitative extraction of nucleotide and sugar phosphates from plant tissue by either boiling aqueous ethanol or cold trichloroacetic acid. The effect of the extraction technique on the inactivation of the enzymes in the plant tissue and the possibility of adsorption of the phosphate esters on the cell wall were especially considered. 2. In the recommended method the plant tissue was frozen in liquid nitrogen, ground to a powder and then blended with cold aqueous trichloroacetic acid containing 8-hydroxyquinoline to prevent adsorption. 3. The extract contained large amounts of trichloroacetic acid, cations, chloride, sugars, amino acids, hydroxy organic acids, phytic acid, orthophosphoric acid and high-molecular-weight material including some phosphorus-containing compounds. All of these were removed as they were liable to interfere with the chromatographic or enzymic assay of the individual nucleotide or sugar phosphates. 4. The procedure was as follows: the last traces of trichloroacetic acid were extracted with ether after the solution had been passed through a column of Dowex AG 50 in the hydrogen form to remove all cations. High-molecular-weight compounds were removed by ultrafiltration and low-molecular-weight solutes by a two-stage chromatography on cellulose columns with organic solvents. In the first stage, sugars, amino acids, chloride and phytic acid were separated by using a basic solvent (propan-1-ol–water–aqueous ammonia) and, in the second stage, the organic acids and orthophosphoric acid were separated by using an acidic solvent (di-isopropyl ether–formic acid–2-methylpropan-2-ol–water). The final solution of nucleotide and sugar phosphates was substantially free from other solutes and was suitable for the detection of individual phosphate esters by either chromatography or enzymic assay. 5. The recovery of d-glucose 6-phosphate or adenosine 5′-triphosphate added to a trichloroacetic acid extract

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

    PubMed

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

    2014-08-01

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

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

    PubMed Central

    2015-01-01

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

  2. Structure-activity correlations for organophosphorus ester anticholinesterases. Part 2: CNDO/2 calculations applied to ester hydrolysis rates

    NASA Technical Reports Server (NTRS)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1984-01-01

    Quantitative structure-activity relationships are presented for the hydrolysis of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. CNDO/2 calculations provide values for molecular parameters that correlate with alkaline hydrolysis rates. For each subset of esters with the same leaving group, X, the CNDO-derived net atomic charge at the central phosphorus atom correlates well with the alkaline hydrolysis rate constants. For the whole set of esters with different leaving groups, equations are derived that relate charge, orbital energy and bond order to the hydrolysis rate constants.

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

    DOEpatents

    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.

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

    DOEpatents

    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.

  5. ESTIMATION OF CARBOXYLIC ACID ESTER HYDROLYSIS RATE CONSTANTS

    EPA Science Inventory

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

  6. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS - ALKALINE HYDROLYSIS

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition state...

  7. Incorporation of Epicatechin Esters into Lignin Enhances Cell Wall Fermentability

    USDA-ARS?s Scientific Manuscript database

    Polyphenolic catechin esters are potentially attractive targets for lignin bioengineering because their copolymerization with monolignols could reduce lignin hydrophobicity and cross-linking to polysaccharides, or facilitate delignification by biomass pretreatments. To test this hypothesis, we biomi...

  8. Long-acting contraceptive agents: levonorgestrel esters of unsaturated acids.

    PubMed

    Wan, A S; Ngiam, T L; Leung, S L; Go, M L; Francisco, C G; Freire, R; Hernandez, R; Salazar, J A; Suarez, E; García, G A

    1983-03-01

    Esters of levonorgestrel (13 beta-ethyl-17 beta-ethynyl-17 beta-hydroxygon-4-en-3-one) with a variety of unsaturated carboxylic acids have been synthesized for evaluation as potential long-acting, injectable contraceptive agents.

  9. Long-acting contraceptive agents: testosterone esters of unsaturated acids.

    PubMed

    Francisco, C G; Freire, R; Gawronski, J; Hernández, R; Kielczewski, M; Salazar, J A; Savabi, F; Shafiee, A; Strekowski, L; Suárez, E

    1990-01-01

    The synthesis of 13 new esters of testosterone is described, with the esterifying acids bearing acetylenic, olefinic, or polyunsaturated functions in the chain, for evaluation as long-acting androgens.

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

    PubMed

    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.

  11. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS - ALKALINE HYDROLYSIS

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition state...

  12. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. I. ALKALINE HYDROLYSIS

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition state...

  13. Epoxy resin composition containing metal tetrafluoroborate and boron ester

    SciTech Connect

    Morehead, G.T.

    1990-06-12

    This patent describes a curable composition. It comprises: a polyepoxide; a metal tetrafluoroborate; and at least one boron ester selected from the group consisting of triesters of boric acid and diesters of boronic acid.

  14. ESTIMATION OF CARBOXYLIC ACID ESTER HYDROLYSIS RATE CONSTANTS

    EPA Science Inventory

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

  15. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. I. ALKALINE HYDROLYSIS

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition state...

  16. Inert Reassessment Document for PEG Fatty Acid Esters

    EPA Pesticide Factsheets

    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)

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

    PubMed

    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. Radiation Basics

    EPA Pesticide Factsheets

    Radiation can come from unstable atoms or it can be produced by machines. There are two kinds of radiation; ionizing and non-ionizing radiation. Learn about alpha, beta, gamma and x-ray radiation, as well the different types of doses.

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

    DOEpatents

    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.

  20. Transport of Glutathione Diethyl Ester Into Human Cells

    NASA Astrophysics Data System (ADS)

    Levy, Ellen J.; Anderson, Mary E.; Meister, Alton

    1993-10-01

    Glutathione monoesters in which the carboxyl group of the glycine residue is esterified were previously found, in contrast to glutathione itself, to be effectively transported into various types of cells and to be converted intracellularly into glutathione. Glutathione monoesters are thus useful for prevention of oxidative stress, certain toxicities, and for treatment of glutathione deficiency. Glutathione diethyl ester is rapidly split to the glutathione monoethyl ester by mouse plasma glutathione diester α-esterase activity. Thus, as expected, glutathione mono- and diesters have similar effects on cellular glutathione levels in mice. However, human plasma lacks glutathione diester α-esterase thus, it became of interest to compare the transport properties of glutathione mono- and diesters in human cells. We found that human cells (erythrocytes, peripheral blood mononuclear cells, fibroblasts, ovarian tumor cells, and purified T cells) transport glutathione diethyl ester much more effectively than the corresponding monoethyl (glycyl) ester. Human cells rapidly convert glutathione diethyl ester to the monoester, whose intracellular levels rise to levels that are significantly higher than levels found after application of the monoester to the cells. High levels of the monoester provide the cells with a means of producing glutathione over a period of time. We conclude that glutathione diethyl ester is highly effective as a delivery agent for glutathione monoester, and thus for glutathione, in human cells and therefore could serve to decrease oxidative stress and toxicity. Hamster (and certain other animals) also lack plasma glutathione diester α-esterase and therefore would be suitable animal models. Previously reported toxicity of certain glutathione ester preparations appears to reflect the presence of impurities rather than effects of the esters.

  1. Pyrazinoic acid esters with broad spectrum in vitro antimycobacterial activity.

    PubMed

    Cynamon, M H; Gimi, R; Gyenes, F; Sharpe, C A; Bergmann, K E; Han, H J; Gregor, L B; Rapolu, R; Luciano, G; Welch, J T

    1995-09-29

    A series of substituted pyrazinoic acid esters has been prepared and examined for their in vitro activity against Mycobacterium avium and Mycobacterium kansasii as well as Mycobacterium tuberculosis. Modification of both the pyrazine nucleus and the ester functionality have been very successful in expanding the activity of pyrazinamide to include M. avium and M. kansasii, organisms normally not susceptible to pyrazinamide. Several of these compounds have activities 100-1000-fold greater than that of pyrazinamide against M. tuberculosis.

  2. Cyanate Ester Composite Resins Derived from Renewable Polyphenol Sources

    DTIC Science & Technology

    2011-03-16

    time to prepare model compounds 3 and 4 (Scheme 4). Recently a chiral version of compound 4 was prepared although no cure chemistry of the cyanate ester...the cure exotherm and its peak temperature near 200 °C suggest that the system is self- catalyzing , either through the presence of impurities or...this could be due to degradation or other chemical reactions triggered at high temperature. Ester groups have been shown to catalyze the cure of

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

    PubMed

    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).

  4. Flavonol and chalcone ester glycosides from Bidens andicola.

    PubMed

    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.

  5. Hydrolysis of organic esters at the mineral/water interface

    SciTech Connect

    Torrents, A.

    1992-01-01

    Organic esters are widely used as insecticides and are part of many commercial products and industrial processes. When these compounds are released into the environment, they contaminate natural resources. To assess their fate and transport it is important to explore degradation and retainment processes. Numerous previous studies have studied the role of adsorption in lowering pollutant concentration and retarding pollutant migration into soils. However, adsorption at the mineral/water interface also affects the mechanisms of degradation and reaction rates. This dissertation research focuses on the ability of metal oxides to catalyze ester hydrolysis and a reaction mechanism is proposed. Furthermore, the authors studied the role of natural occurring adsorbates on the reaction rates. The oxides used in this study are amorphous silica (SiO[sub 2]), [gamma]-aluminum oxide (Al[sub 2]O[sub 3]), anatase (TiO[sub 2]), and geothite (FeOOH). These either occur naturally, or are similar to naturally occurring surfaces. The capability of such oxides to catalyze ester hydrolysis was studied in batch reactors. The organic compounds investigated were carboxylic acid esters and organophosphate pesticides. The hydrolysis of several esters was catalyzed by the presence of oxide suspensions; the extent of catalysis was dependent on the ester structure, the metal oxide, and solution composition. Results suggest that catalysis for carboxylate esters occurs via a surface chelate formation between the carbonyl oxygen, a second donor group of the ester and the surface metal. The presence of organic co-solvents appears to diminish the catalytic effect. Inhibition of surface catalysis was also observed from specific adsorption of naturally occurring ions onto the oxide surface. Natural organic matter was also observed to influence surface catalysis. This research suggests that mineral surfaces may have a role in abiotic transformations of organic pollutants.

  6. Sunflower methyl esters for direct injected diesel engines

    SciTech Connect

    Kaufman, K.R.; Ziejewski, M.

    1984-11-01

    A methyl ester of sunflower oil was durability tested in direct injected, turbocharged and intercooled diesel engine. A test cycle recommended by the Alternate Fuels Committee of the Engine Manufacturer's Assocation was used. The results are compared to a baseline test using diesel fuel. Based on the results, the methyl ester fuel successfully completed the 200-hour durability test. Field tests and engine manufacturers evaluations are needed to further quantify the long term effect of the fuel on engine durability. 14 references.

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

    DTIC Science & Technology

    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

  8. Antiviral Effects of Amphotericin B Methyl Ester

    PubMed Central

    Jordan, George W.; Seet, Elizabeth C.

    1978-01-01

    The methyl ester of amphotericin B (AME) is water soluble, retains antifungal activity, and is significantly less toxic in mammals than amphotericin B. In contrast to amphotericin B, which is not water soluble, AME exhibits antiviral effects against vesicular stomatitis virus, herpes simplex virus types 1 and 2, Sindbis virus, and vaccinia virus in a plaque reduction assay. No antiviral effects could be demonstrated against the unenveloped adenovirus type 4 or echovirus type 11. The extent of virus inactivation was found to be dependent upon the AME concentration, contact time, and temperature. No consistent effect of the virus concentration on the probability of plaque-forming unit inactivation could be determined. The antiviral effects of AME were partially antagonized by the presence of serum. Binding of AME to vesicular stomatitis virus was demonstrated by the comigration of drug and virus in linear sucrose gradients. AME represents a new class of antiviral agents with activity at concentrations relevant to therapeutics. Sterol components of the host cell membrane that become incorporated into the viral envelope are postulated as the site of reaction with AME. PMID:206201

  9. Ultimate biodegradation of dialkyl phthalate ester plasticizers

    SciTech Connect

    Lee, C.L.; Sinko, C.J.; Winkelmann, D.A.; Peterson, D.R.; Parkerton, T.F.

    1995-12-31

    Phthalate Esters (PEs) are primarily used as plasticizers in the polymer industry to impart the desired degree of flexibility to plastic products. The single isomer, di-2-ethylhexyl phthalate (DEHP) is the most common plasticizer. However, other commercially important PE plasticizers possess branched alkyl chains of a mixed isomeric nature. The purpose of this study was to compare the ultimate biodegradability of mixed isomer PEs dihexyl (DHP), diisoheptyl (DIHP), diisononyl (DINP), diisodecyl (DIDP), and diisoundecyl (DIUP) phthalate to DEHP using the standardized OECD test (301 F) which is based on mannometric respirometry. Ultimate biodegradation results after 28 days under unacclimated conditions at 25 C were as follows: DHP (80 {+-} 10%), DIHP (82 {+-} 13%), DEHP (63 {+-} 18%), DINP (70 {+-} 11%), DIDP (67 {+-} 13%), DUP (57 {+-} 14%). These data confirm the readily biodegradable nature of DEHP and mixed isomer PEs reported in previous studies and provide additional data to contradict the misperception that PEs are environmentally persistent. The influence of alkyl chain structure on the rate and extent of biodegradation observed in this and other biodegradation studies are discussed.

  10. Ecotoxicity studies of the levulinate ester series.

    PubMed

    Lomba, Laura; Muñiz, Selene; Pino, Ma Rosa; Navarro, Enrique; Giner, Beatriz

    2014-10-01

    The increasing interest in the development of novel green solvents has led to the synthesis of benign alternative products with minimized environmental impacts. However, most of published studies on green solvents focus primarily on their physicochemical properties, with limited emphasis on absence of ecotoxicological assessment. In this study, we evaluated the acute ecotoxicity of four levulinates (levulinic acid, methyl levulinate, ethyl levulinate and butyl levulinate) on freshwater algae (Chlamydomonas reinhardtii), bacteria (Vibrio fischeri), daphnids (Daphnia magna) and earthworms (Eisenia foetida) using various dose-response tests. As a general trend, the toxicity of levulinate esters in aquatic exposure (assessed as the EC50) increased as a function of increasing alkyl chain length; accordingly, the most toxic compound for the aquatic organisms was butyl levulinate, followed by ethyl levulinate and methyl levulinate. The most toxic compound for E. foetida (terrestrial exposure) was methyl levulinate, followed by ethyl levulinate, butyl levulinate and levulinic acid; in this case, we observed an inverse relationship between toxicity and alkyl chain length. Based on both the lowest EC50 found in the aquatic media and the ratio between predicted environmental concentration and the predicted no-effect concentration, we have estimated the maximum allowable values in the environment for these chemicals to be 1.093 mg L(-1) for levulinic acid, 2.761 mg L(-1) for methyl levulinate, 0.982 mg L(-1) for ethyl levulinate and 0.151 mg L(-1) for butyl levulinate.

  11. Polynitroethyl- and fluorodinitroethyl substituted boron esters.

    PubMed

    Klapötke, Thomas M; Krumm, Burkhard; Moll, Richard

    2013-09-02

    The reaction of boron oxide with various nitro-substituted ethanols (2-nitroethanol, 2-fluoro-2,2-dinitroethanol, 2,2,2-trinitroethanol) furnished the corresponding nitroethyl borates B(OCH2CH2NO2)3 (1), B(OCH2CF(NO2)2)3 (2), and B(OCH2C(NO2)3)3 (3). Fluorination of the anion [(NO2)2CCH2OH](-) (4) resulted in 2-fluoro-2,2-dinitroethanol (5), a precursor for 2, and was thoroughly characterized. An interesting condensation was observed with the anion 4 to form the unusual dianion [(NO2)2CCH2C(NO2)2](2-) (6). All compounds were fully characterized by multinuclear NMR spectroscopy, vibrational spectroscopy (IR, Raman), mass spectrometry and elemental analysis. The chemical, physical and energetic properties of 1-3 and 5 are reported, as well as quantum chemical calculations at the CBS-4M level of theory to predict the enthalpies and energies of formation. X-ray diffraction studies were performed, and the crystal structures for compounds 1-6 were determined and discussed thoroughly. The boron esters 1-3 are of interest as possible candidates for smoke-free, green colorants in pyrotechnic applications, and in case of 2 and 3 also as promising high energy oxidizers. Copyright © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Study of thermal behaviour of sugar esters.

    PubMed

    Szuts, Angéla; Pallagi, Edina; Regdon, Géza; Aigner, Zoltán; Szabó-Révész, Piroska

    2007-05-24

    Sugar esters (SEs) are widely used in the pharmaceutical and food industries. They have a wide range of HLB values (1-16), and hence they can be applied as surfactants, or as solubility or penetration enhancers. SEs can be employed in hot-melt technology, because their melting points are low and they decompose only above 220 degrees C. The aims of this work were to study the thermal properties of SEs and to demonstrate differences between SEs with various HLB values. The results revealed that SEs with high or medium HLB values were vitrified by melting. Their glass transitions (T(g)) were determined by modulated differential scanning calorimetry. To visualize the changes in the samples during heating, hot-stage microscopy was used. Hydrophilic SEs were only softened, while lipophilic SEs were melted by heating. After melting and solidification, SEs have partially amorphous layered structures which slowly crystallize in time. Time-dependent solid-state changes (crystalline and amorphous phases) were observed, and analysed by means of differential scanning calorimetry and X-ray powder diffraction.

  13. Polyenylcyclopropane carboxylic esters with high insecticidal activity.

    PubMed

    Ferroni, Claudia; Bassetti, Lucio; Borzatta, Valerio; Capparella, Elisa; Gobbi, Carlotta; Guerrini, Alberto; Varchi, Greta

    2015-05-01

    Pyrethroids are synthetic derivatives of naturally occurring pyrethrum. These molecules are widely used in agriculture for ant, fly and mosquito control and for lawn and garden care. Pyrethroids are the optically active esters of 2,2-dimethyl-3-(2-methylpropenyl)-cyclopropane carboxylic acid, also known as chrysanthemic acid. However, their intense use has resulted in the development of resistance in many insect species. Herein, specific structural modifications of the pyrethroid scaffold and their effect on insecticidal activity, especially on resistant pests strains, are reported. The exposure to (1R)-trans-(E/Z)-2,3,5,6-tetrafluorobenzyl-3-(buta-1,3-dienyl)-2,2-dimethyl cyclopropanecarboxylate and its diastereomers produced 100% mortality in yellow fever mosquitoes (Aedes aegypti), house mosquitoes (Culex quinquefasciatus) and houseflies (Musca domestica). Moreover, this compound provided complete knockdown within 15 min of exposure against cockroaches (Blattella germanica) and maintained an excellent knockdown activity at 10 days after treatment. Novel pyrethroid derivatives obtained from 2,2-dimethyl-3-(2-methylpropenyl)-cyclopropanecarboxylic acid are described. These derivatives display high insecticidal activity, a wide spectrum of action and no toxicity towards mammalians. The proposed synthetic procedures are highly efficient and inexpensive, and therefore suitable for industrial scale-up. © 2014 Society of Chemical Industry.

  14. Kinetic modelling of vinyl ester resin polymerization

    SciTech Connect

    Dhulipala, R.; Kreig. G.; Hawley, M.C.

    1993-12-31

    The study of kinetics offers a substantional incentive in the endeavor to manufacture polymer matrix composites at high speeds. The study enables one to optimize the curing cycle based on the specific curing characteristics of the resin and also makes it possible to simulate the curing process. This paper reports the results of the modelling of the thermal curing of the vinyl ester resin. The parameters for the proposed model have been calculated based on conversion-vs-data generated at various temperatures and Benzoyl peroxide (initiator) concentrations. The extent of cure of the resin mixture was determined using Fourier Transform Infrared Spectroscopy. In this model the termination rate constant is considered to drop with extent of cure until a limiting value is reached. The limiting value is a consequence of the active chain ends possessing a degree of mobility due to the propagation reaction even though the translational motion of the growing for radicals in increasingly restricted with conversion. Good agreements is observed between the model predictions and the experimental data.

  15. Nanohydroxyapatite/poly(ester urethane) scaffold for bone tissue engineering.

    PubMed

    Boissard, C I R; Bourban, P-E; Tami, A E; Alini, M; Eglin, D

    2009-11-01

    Biodegradable viscoelastic poly(ester urethane)-based scaffolds show great promise for tissue engineering. In this study, the preparation of hydroxyapatite nanoparticles (nHA)/poly(ester urethane) composite scaffolds using a salt-leaching-phase inverse process is reported. The dispersion of nHA microaggregates in the polymer matrix were imaged by microcomputed X-ray tomography, allowing a study of the effect of the nHA mass fraction and process parameters on the inorganic phase dispersion, and ultimately the optimization of the preparation method. How the composite scaffold's geometry and mechanical properties change with the nHA mass fraction and the process parameters were assessed. Increasing the amount of nHA particles in the composite scaffold decreased the porosity, increased the wall thickness and consequently decreased the pore size. The Young's modulus of the poly(ester urethane) scaffold was improved by 50% by addition of 10 wt.% nHA (from 0.95+/-0.5 to 1.26+/-0.4 MPa), while conserving poly(ester urethane) viscoelastic properties and without significant changes in the scaffold macrostructure. Moreover, the process permitted the inclusion of nHA particles not only in the poly(ester urethane) matrix, but also at the surface of the scaffold pores, as shown by scanning electron microscopy. nHA/poly(ester urethane) composite scaffolds have great potential as osteoconductive constructs for bone tissue engineering.

  16. Biocatalytic synthesis of ascorbyl esters and their biotechnological applications.

    PubMed

    Karmee, Sanjib Kumar

    2009-01-01

    Ascorbyl fatty acid esters act both as antioxidants and surfactants. These esters are obtained by acylation of vitamin C using different acyl donors in presence of chemical catalysts or lipases. Lipases have been used for this reaction as they show high regioselectivity and can be used under mild reaction conditions. Insolubility of hydrophilic ascorbic acid in non-polar solvents is the major obstacle during ascorbic acid esters synthesis. Different strategies have been invoked to address this problem viz. use of polar organic solvents, ionic liquids, and solid-phase condensation. Furthermore, to improve the yield of ascorbyl fatty acid esters, reactions were performed by (1) controlling water content in the reaction medium, (2) using vacuum to remove formed volatile side product, and (3) employing activated acyl donors (methyl, ethyl or vinyl esters of fatty acids). This mini-review offers a brief overview on lipase-catalyzed syntheses of vitamin C esters and their biotechnological applications. Also, wherever possible, technical viability, scope, and limitations of different methods are discussed.

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

    PubMed

    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.

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

    EPA Pesticide Factsheets

    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

  19. Incomplete hydrolysis of cholesteryl esters during the enzymatic cholesterol determination as evidenced by aqueous cholesteryl ester solutions: comparison of six enzymatic procedures with the Liebermann-Burchard method.

    PubMed

    Tel, R M; Berends, G T

    1980-10-01

    Aqueous solutions of cholesterol and some cholesteryl esters were prepared. The hydrolysis of cholesteryl esters with enzymatic methods could therefore be studied in some detail. The total cholesterol concentration of the aqueous cholesterol and cholesteryl ester solutions was determined by 6 different enzymatic procedures as well as the Liebermann-Burchard method. For some esters (acetate and arachidonate esters) the esterase reaction is not complete within the usual reaction time, whereas most other esters gave analytical results lower than the theoretical. With the Liebermann-Burchard method all esters reacted completely within the reaction time. The esterase have very different specificities for the various cholesteryl esters. With the enzymatic method several commercial control sera as well as human sera gave lower cholesterol concentrations than the Liebermann-Burchard method. These differences can be explained mainly by this incomplete hydrolysis. Some practical recommendations are given.

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    PubMed

    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.

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

    SciTech Connect

    Hohl, G.H.

    1995-12-31

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

  4. Fibers by bioresorbable poly(ester-ether-ester)s as potential suture threads: a preliminary investigation.

    PubMed

    Guerra, G D; Cerrai, P; Tricoli, M; Maltinti, S; Anguillesi, I; Barbani, N

    1999-01-01

    Fibers made by a bioresorbable poly(epsilon-caprolactone)-block-poly(oxyethylene)-block-poly(epsilon-caprolactone) copolymer, having a number average molecular mass of about 200,000 Da and an average molar composition of 66% oxycaproyl units and 34% oxyethylene units, were melt-spun, with the aim at using them as suture threads. Their properties were investigated by the stress-strain test and by differential scanning calorimetry (DSC). The results obtained show that the properties of this material depend very strongly on the alignment of its macromolecules. In particular, the only partial alignment, obtainable by a relatively moderate drawing just after the extrusion, leads to values of elongation at break too high for use of the fibers as suture threads. The DSC analysis reveals interesting properties of the material, but also confirms their strong dependence on the extrusion procedure and on the mechanical treatment. In conclusion, the results of this preliminary study show that the spinning technique must be improved, and that further investigations are necessary to ascertain the possibility of using these poly(ester-ether-ester)s for the fabrication of suture threads.

  5. Extraction and Liquid Chromatography-Tandem Mass Spectrometry Detection of 3-Monochloropropanediol Esters and Glycidyl Esters in Infant Formula.

    PubMed

    Leigh, Jessica K; MacMahon, Shaun

    2016-12-14

    A method was developed for the extraction of fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD) and glycidol from infant formula, followed by quantitative analysis of the extracts using liquid chromatography-tandem mass spectrometry (LC-MS/MS). These process-induced chemical contaminants are found in refined vegetable oils, and studies have shown that they are potentially carcinogenic and/or genotoxic, making their presence in edible oils (and processed foods containing these oils) a potential health risk. The extraction procedure involves a liquid-liquid extraction, where powdered infant formula is dissolved in water and extracted with ethyl acetate. Following shaking, centrifugation, and drying of the organic phase, the resulting fat extract is cleaned-up using solid-phase extraction and analyzed by LC-MS/MS. Method performance was confirmed by verifying the percent recovery of each 3-MCPD and glycidyl ester in a homemade powdered infant formula reference material. Average ester recoveries in the reference material ranged from 84.9 to 109.0% (0.6-9.5% RSD). The method was also validated by fortifying three varieties of commercial infant formulas with a 3-MCPD and glycidyl ester solution. Average recoveries of the esters across all concentrations and varieties of infant formula ranged from 88.7 to 107.5% (1.0-9.5% RSD). Based on the validation results, this method is suitable for producing 3-MCPD and glycidyl ester occurrence data in all commercially available varieties of infant formula.

  6. Analytical approaches for MCPD esters and glycidyl esters in food and biological samples: a review and future perspectives.

    PubMed

    Crews, C; Chiodini, A; Granvogl, M; Hamlet, C; Hrnčiřík, K; Kuhlmann, J; Lampen, A; Scholz, G; Weisshaar, R; Wenzl, T; Jasti, P R; Seefelder, W

    2013-01-01

    Esters of 2 - and 3-monochloropropane-1,2-diol (MCPD) and glycidol esters are important contaminants of processed edible oils used as foods or food ingredients. This review describes the occurrence and analysis of MCPD esters and glycidol esters in vegetable oils and some other foods. The focus is on the analytical methods based on both direct and indirect methods. Methods of analysis applied to oils and lipid extracts of foods have been based on transesterification to free MCPD and determination by gas chromatography-mass spectrometry (indirect methods) and by high-performance liquid chromatography-mass spectrometry (direct methods). The evolution and performance of the different methods is described and their advantages and disadvantages are discussed. The application of direct and indirect methods to the analysis of foods and to research studies is described. The metabolism and fate of MCPD esters and glycidol esters in biological systems and the methods used to study these in body tissues studies are described. A clear understanding of the chemistry of the methods is important when choosing those suitable for the desired application, and will contribute to the mitigation of these contaminants.

  7. Space Radiation

    NASA Technical Reports Server (NTRS)

    Wu, Honglu

    2006-01-01

    Astronauts receive the highest occupational radiation exposure. Effective protections are needed to ensure the safety of astronauts on long duration space missions. Increased cancer morbidity or mortality risk in astronauts may be caused by occupational radiation exposure. Acute and late radiation damage to the central nervous system (CNS) may lead to changes in motor function and behavior, or neurological disorders. Radiation exposure may result in degenerative tissue diseases (non-cancer or non-CNS) such as cardiac, circulatory, or digestive diseases, as well as cataracts. Acute radiation syndromes may occur due to occupational radiation exposure.

  8. Light induced degradation of phorbol esters.

    PubMed

    Yunping, Bu; Ha, Bui Thi Ngoc; Eunice, Yeo; Chueng, Lo Loong; Yan, Hong

    2012-10-01

    Jatropha curcas (Jatropha) is a tropical shrub that is gaining popularity as a biofuel feedstock plant. Phorbol esters (PEs) are tetracyclic tiglian diterpenoids that are present in Jatropha seeds and other parts of plant. Epidermal cell irritating and cancer promoting PEs not only reduce commercial values of Jatropha seed cake but also cause some safety and environment concerns on PE leaching to soil. A simple bioassay of PE toxicity was conducted by incubating 48 h old brine shrimp (Artemia salina) nauplii with Jatropha oil for 24 h. 1-4% of Jatropha oil (corresponding to PE concentration of 25-100 mg L(-1)) had mortality rate of 5-95%, with LC50 estimated to be 2.7% of oil or 67 mg L(-1) of PE. Jatropha oil was incubated with clay or black soil (autoclaved or non-autoclaved) in the darkness or under sunlight for different periods of time before oil was re-extracted and tested for PE content by HPLC and for remaining toxicity with the brine shrimp bioassay. Under sunlight, PE decreased to non-detectable level within six days. Toxicity reduced to less than 5% mortality rate that is comparable to rapeseed oil control within the same period. In contrast, PE level and toxicity remained little changed when Jatropha oil was incubated in the darkness. Such PE degradation/detoxification was also found independent of the presence of soil or soil microorganisms. We conclude that sunlight directly degrades and detoxifies PEs and this finding should alleviate the concern on long term environmental impact of PE leaching. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Radiation Therapy: Professions in Radiation Therapy

    MedlinePlus

    ... Resources Professions Site Index A-Z Professions in Radiation Therapy Radiation Oncologist Therapeutic Medical Physicist Radiation Therapist Dosimetrist Radiation Oncology Nurse Social Worker Dietitian Radiation Oncologist Radiation oncologists are physicians who oversee the ...

  10. Lipoprotein products of lecithin: cholesterol acyltransferase and cholesteryl ester transfer.

    PubMed

    Rose, H G; Ellerbe, P

    1982-09-14

    High-density lipoprotein substrates and products of human plasma lecithin: cholesterol acyltransferase have been labelled with radioisotopic cholesteryl esters in order to facilitate identification. [3H]Cholesteryl esters were formed by endogenous HDL3/VHDL enzyme (d greater than 1.125 g/ml) following incubation with mixed vesicles of phosphatidylcholine, unesterified cholesterol and 3H-labelled unesterified cholesterol. Transfer of labelled esters to acceptor lipoproteins (VLDL+LDL, d less than 1.063 g/ml) was employed to distinguish a hypothetical transfer complex. Separation of labelled HDL3/VHDL was by gel-permeation chromatography. The results indicate that a subpopulation of labelled HDL3/VHDL cholesteryl esters (43-61% of total) were removed by VLDL/LDL during a 3 h transfer period and these derive from the smaller lipoproteins of the spectrum. HDL carrying non-transferable [3H]cholesteryl esters localize to the larger HDL3. Transfer rates were proportional to ratios of acceptor to donor lipoproteins. Net transfer of cholesteryl esters from the smaller HDL3 also occurred, but was smaller in magnitude (about 10.5% of total). Acyltransferase assays indicated that enzyme distribution is skewed to larger-sized HDL3, suggesting that the non-transferable components might be lecithin: cholesterol acyltransferase-containing parent complexes, while the smaller transfer products contain little acyltransferase. The results fit the hypothesis that a parent HDL3-lecithin: cholesterol acyltransferase complex generates a smaller-sized lipoprotein product which is active in cholesteryl ester transport.

  11. Fatty acid alcohol ester-synthesizing activity of lipoprotein lipase.

    PubMed

    Tsujita, T; Sumiyoshi, M; Okuda, H

    1999-12-01

    The fatty acid alcohol ester-synthesizing activity of lipoprotein lipase (LPL) was characterized using bovine milk LPL. Synthesizing activities were determined in an aqueous medium using oleic acid or trioleylglycerol as the acyl donor and equimolar amounts of long-chain alcohols as the acyl acceptor. When oleic acid and hexadecanol emulsified with gum arabic were incubated with LPL, palmityl oleate was synthesized, in a time- and dose-dependent manner. Apo-very low density lipoprotein (apoVLDL) stimulated LPL-catalyzed palmityl oleate synthesis. The apparent equilibrium ratio of fatty acid alcohol ester/oleic acid was estimated using a high concentration of LPL and a long (20 h) incubation period. The equilibrium ratio was affected by the incubation pH and the alcohol chain length. When the incubation pH was below pH 7.0 and long chain fatty acyl alcohols were used as substrates, the fatty acid alcohol ester/free fatty acid equilibrium ratio favored ester formation, with an apparent equilibrium ratio of fatty acid alcohol ester/fatty acid of about 0.9/0.1. The equilibrium ratio decreased sharply at alkaline pH (above pH 8.0). The ratio also decreased when fatty alcohols with acyl chains shorter than dodecanol were used. When a trioleoylglycerol/fatty acyl alcohol emulsion was incubated with LPL, fatty acid alcohol esters were synthesized in a dose- and time-dependent fashion. Fatty acid alcohol esters were easily synthesized from trioleoylglycerol when fatty alcohols with acyl chains longer than dodecanol were used, but synthesis was decreased with fatty alcohols with acyl chain lengths shorter than decanol, and little synthesizing activity was detected with shorter-chain fatty alcohols such as butanol or ethanol.

  12. Radiation safety.

    PubMed

    Skinner, Sarah

    2013-06-01

    Diagnostic radiology procedures, such as computed tomography (CT) and X-ray, are an increasing source of ionising radiation exposure to our community. Exposure to ionising radiation is associated with increased risk of malignancy, proportional to the level of exposure. Every diagnostic test using ionising radiation needs to be justified by clinical need. General practitioners need a working knowledge of radiation safety so they can adequately inform their patients of the risks and benefits of diagnostic imaging procedures.

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

    PubMed

    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

  14. [Polyamides and esters of terephthalic acid used in the production of medical articles to be sterilized by accelerated electrons].

    PubMed

    Robalewski, A M; Skajster, J; Krejzler, R

    1975-01-01

    The paper concerns the study on the resistance of home-made polyamides and polyterephthalic acid esters used for manufacture of medical equipment to the effect of accelerated electron radiation. The studied polyamides were found to be unfit for medical articles manufacture without removal of soluble components of the plastics. Sterilization with accelerated electrons results in limited advantageous changes in polyamide properties. Medical articles made of polyethylene terephthalate can be successfully sterilized in electron accelerator with no changes in characteristics even upon prolonged storage.

  15. Radiation Exposure

    MedlinePlus

    Radiation is energy that travels in the form of waves or high-speed particles. It occurs naturally in sunlight. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment. If you are exposed to small amounts of radiation over a ...

  16. Disordering by γ-irradiation on long range order of liquid crystalline phases of cholesteryl esters

    NASA Astrophysics Data System (ADS)

    Srivastava, S. L.; Dhar, R.

    1992-10-01

    Effect of γ-irradiation from Co60 of radiation doze 50 MRad on the dielectric and thermodynamical properties of cholesteryl myristate (ChM) and cholesteryl pelargonate (ChP) have been studied by an electric impedance analyzer and differential scanning calorimeter (DSC). The mesophase transition temperatures, the enthalpy and the entropy of the transitions are depressed, and transition curves become asymmetric and wide on γ-irradiation. From the depressions in crystal to mesophase transition temperatures of ChM and ChP, we have estimated the molar fraction of impurity like fragments produced due to γ-irradiation of 50 MRad doze to be about 10%. Dielectric study of planar oriented samples of these two esters in the frequency range of 1 kHz to 10 MHz shows that due to γ-irradiation dielectric loss (ɛ`) is increased by 50 to 150% in different mesophases while dielectric constant (ɛ') is almost unchanged.

  17. Rheological behavior and cryogenic properties of cyanate ester/epoxy insulation material for fusion superconducting magnet

    SciTech Connect

    Wu, Z. X.; Huang, C. J.; Li, L. F.; Li, J. W.; Tan, R.; Tu, Y. P.

    2014-01-27

    In a Tokamak fusion reactor device like ITER, insulation materials for superconducting magnets are usually fabricated by a vacuum pressure impregnation (VPI) process. Thus these insulation materials must exhibit low viscosity, long working life as well as good radiation resistance. Previous studies have indicated that cyanate ester (CE) blended with epoxy has an excellent resistance against neutron irradiation which is expected to be a candidate insulation material for a fusion magnet. In this work, the rheological behavior of a CE/epoxy (CE/EP) blend containing 40% CE was investigated with non-isothermal and isothermal viscosity experiments. Furthermore, the cryogenic mechanical and electrical properties of the composite were evaluated in terms of interlaminar shear strength and electrical breakdown strength. The results showed that CE/epoxy blend had a very low viscosity and an exceptionally long processing life of about 4 days at 60 °C.

  18. Present status of two-dimensional ESTER models: Application to Be stars

    NASA Astrophysics Data System (ADS)

    Rieutord, M.; Espinosa, Lara F.

    2013-11-01

    ESTER two-dimensional models solve the steady state structure of fast rotating early-type stars including the large scale flows associated with the baroclinicity of the radiative zones. Models are compared successfully to the fundamental parameters of the two main components of the triple system δ Velorum that have been derived from interferometric and orbit measurements. Testing the models on the Be star Achernar (α Eri), we cannot reproduce the data and conclude that this star has left the main sequence and is likely crossing the Herzsprung gap. Computing main sequence evolution of fast rotating stars at constant angular momentum shows that their criticality increases with time suggesting that the Be phenomenon and the ensuing mass ejections is the result of evolution.

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

    PubMed

    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.

  20. Effect of temperature stress on protein methyl esters

    SciTech Connect

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

    PubMed

    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.

  2. Determination of testosterone esters and estradiol esters in bovine and porcine blood serum.

    PubMed

    Rejtharová, Martina; Rejthar, Libor; Čačková, Katarína

    2017-04-01

    Monitoring of steroid esters in blood serum is desirable in order to detect the possible illegal use of natural hormones as growth promoters. A method for the determination of testosterone propionate, testosterone benzoate, testosterone isocaproate, testosterone decanoate and estradiol benzoate in bovine and porcine blood serum was developed. The procedure consists of protein precipitation and removal of phospholipids using a HybridSPE®-Phospholipid column followed by clean-up on a hydrophilic modified styrene polymer Supel(TM)-Select HLB column and LC-MS/MS measurement. The method was validated according to Commission Decision 2002/657/EC. Decision limits for all analytes were observed in the range 5-30 pg ml(-)(1). The method was shown to be robust for bovine and porcine serum analyses and can be applied for both screening and confirmatory determination in routine residue monitoring.

  3. Radiation Proctopathy

    PubMed Central

    Grodsky, Marc B.; Sidani, Shafik M.

    2015-01-01

    Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options. PMID:26034407

  4. Radiation Protection

    NASA Astrophysics Data System (ADS)

    Grupen, Claus

    Radiation protection is a very important aspect for the application of particle detectors in many different fields, like high energy physics, medicine, materials science, oil and mineral exploration, and arts, to name a few. The knowledge of radiation units, the experience with shielding, and information on biological effects of radiation are vital for scientists handling radioactive sources or operating accelerators or X-ray equipment. This article describes the modern radiation units and their conversions to older units which are still in use in many countries. Typical radiation sources and detectors used in the field of radiation protection are presented. The legal regulations in nearly all countries follow closely the recommendations of the International Commission on Radiological Protection (ICRP). Tables and diagrams with relevant information on the handling of radiation sources provide useful data for the researcher working in this field.

  5. Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2011-07-01

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

  7. Production of phthalate esters by nuisance freshwater algae and cyanobacteria.

    PubMed

    Babu, Bakthavachalam; Wu, Jiunn-Tzong

    2010-10-01

    Phthalate esters are widely distributed pollutants which originate from synthetic plasticizer and are known to act as toxicants as well as environmental pheromones in the aquatic ecosystems. From investigating sixteen species of freshwater algae and cyanobacteria we revealed that some of them were capable of producing either di(n-butyl)phthalate (DBP) or mono(2-ethylhexyl)phthalate (MEHP) or both. These phthalate esters would be released into the environment under stress conditions. The incubation of the cells in culture medium containing NaH(13)CO(3) confirmed that both phthalates were de novo synthesized by the studied cells. This study suggested that the nuisance freshwater micro-algae and cyanobacteria growing in eutrophic waters might affect the aquatic ecosystem via the production of these phthalate esters.

  8. Ester oxidation on an aluminum surface using chemiluminescence

    NASA Technical Reports Server (NTRS)

    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.

  9. Electron driven processes in chlorodifluoroacetic acid methyl ester

    NASA Astrophysics Data System (ADS)

    Kopyra, Janina

    2014-07-01

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

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

    PubMed

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

    2014-11-14

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

  11. Gas Phase Spectroscopic Investigation of Chromate-Esters

    NASA Astrophysics Data System (ADS)

    Kaufman, Sydney H.; Weber, J. Mathias

    2012-06-01

    Chromate and dichromate ions are frequently used in the oxidation of alcohols. Chromate esters containing a Cr--O--C bridge are thought to be important intermediates in such reactions. We report the photofragment action spectra of two chromate ester complexes in the UV and visible regions, both of which primarily undergo cleavage of the chromate ester bond resulting in reduction of the chromate from Cr(VI) to Cr(V). Comparison to the UV/Vis absorption spectrum of a methanolic dichromate solution suggests the electronic transitions are the same ligand-to-metal charge transfer transitions in both environments. Comparing the spectral features for different fragment channels leads to insight into the energetics and fragmentation mechanism of these species.

  12. Simultaneous determination and differentiation of glycidyl esters and 3-monochloropropane-1,2-diol (MCPD) esters in different foodstuffs by GC-MS.

    PubMed

    Küsters, Markus; Bimber, Ute; Reeser, Sebastian; Gallitzendörfer, Rainer; Gerhartz, Michael

    2011-06-08

    The aim of this study was the development of a method for the simultaneous determination and differentiation of fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD esters) and glycidol (glycidyl esters) in different foodstuffs. The esters were isolated from fat-rich food samples using a single extraction step and separated from interfering substances. For differentiation of 3-MCPD esters and glycidyl esters the glycidol moiety was converted into 3-methoxypropane-1,2-diol (3-MPD) by acidic alcoholysis. Subsequent determination was achieved by isotope dilution GC-MS after transesterification using an isotope-labeled 3-MCPD ester as internal standard. During optimization of the procedure, critical parameters affecting simultaneous determination and differentiation of these analytes were investigated. Rapid ester cleavage and derivatization at ambient temperature proved to be essential for the simultaneous determination of these analytes. The method was validated for various fat-rich foodstuffs such as bakery products, sweets, gravy, and soup powders as well as edible fats and oils. LODs of 8 and 15 μg/kg (fat-rich foodstuffs) as well as 50 and 65 μg/kg (edible oils and fats) were obtained for 3-MCPD esters and glycidyl esters, respectively. Recoveries for 3-MCPD esters and glycidyl esters ranged within 98 ± 4 and 88 ± 2% in all tested foodstuffs (0.05-2.5 mg/kg) and within 99 ± 16 and 93 ± 13% for edible oils and fats (0.15-3 mg/kg) over a wide concentration range. These results proved an accurate and differentiated determination of 3-MCPD esters and glycidyl esters with successful application to the fast screening of samples, avoiding tedious and laborious sample preparation.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  14. Removal of cholesteryl ester from hepatic reticuloendothelial cells in vivo is not enhanced by plasma cholesteryl ester transfer protein.

    PubMed

    Stein, O; Dabach, Y; Hollander, G; Stein, Y

    1991-01-28

    The putative role of cholesteryl ester transfer protein (CETP) in the removal of cholesteryl ester from hepatic reticuloendothelial cells in vivo was studied in hamsters. The parameter tested was retention of [3H]cholesteryl linoleyl ether ([3H]CLE), a nonhydrolysable analog of cholesteryl ester, in the liver after injection of [3H]CLE labeled acetylated LDL, which is targetted to nonparenchymatous littoral cells. In hamsters fed laboratory chow, plasma cholesteryl ester transfer activity (CETA) was 10.6 +/- 0.9 units and the retention of [3H]CLE in the liver 28 days after injection was 86% of the 4 h value. It was about 55% in rats fed the same diet, in which CETA was not detectable. When the diet was supplemented with 2% cholesterol and 15% margarine, CETA activity in hamsters increased 2-fold, yet no change in retention of [3H]CLE in liver was seen after 28 days. In rats, the retention of [3H]CLE in the liver was also not changed by the dietary fat supplementation. These results do not support the role of CETP in vivo in removal of cholesteryl ester from intact reticuloendothelial cells.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  16. [Effect of macrocyclic esters on mitochondrial and phosphatidylcholine membranes].

    PubMed

    Bogatskiĭ, A V; Luk'ianenko, N G; Nazarov, E I; Nazarova, N Iu; Konup, I P

    1982-01-01

    It has been found that some macrocyclic esters have no ionophoric properties, but can block valinomycin-induced potassium transport in mitochondrial membranes and lessen the potassium current induced by valinomycin in phosphatidylcholine bilayers. It has been also discovered that 36-member cyclic esters of succinic acid and propylene glycoles decrease fluorescence of puridine nucleotides in mitochondria and produce a modifying effect on bimolecular phosphatidylcholine membranes in the medium of litium, calcium and magnesium chlorides at unilateral injection. The results obtained suggest that cyclopolyesters under investigation form mixed complexes with the macromolecules in the composition of mitochondrial and phosphatidylcholine membranes with the participation of the integrated ion.

  17. Switchable Surface Wettability by Using Boronic Ester Chemistry.

    PubMed

    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.

  18. The polymorphic and mesomorphic behavior of four esters of cholesterol.

    NASA Technical Reports Server (NTRS)

    Merritt, W. G.; Cole, G. D.; Walker, W. W.

    1971-01-01

    The techniques of differential scanning calorimetry, X-ray powder diffractometry, and positron annihilation have been used to study the polymorphic and mesomorphic behavior of the following esters of cholesterol: cholesteryl formate, cholesteryl butyrate, cholesteryl benzoate, and cholesteryl cinnamate. Each of these compounds exhibits a single mesophase of the cholesteric type. The solid phase formed from the melt for each ester was observed to be structurally different from the solid phase obtained from solution. Solvents from which the solution-grown samples were crystallized were as follows: cholesteryl formate and cholesteryl butyrate from acetone, cholesteryl benzoate from benzene, and cholesteryl cinnamate from 2-butanone.

  19. Effect of ester impurities in PMR-polyimide resin

    NASA Technical Reports Server (NTRS)

    Lauver, R. W.

    1976-01-01

    Spectral and chomatographic studies were conducted which established the presence of tri- and tetraester impurities in aged monomer solutions employed in fabrication of PMR-polyimide resin composites. The equilibrium constant and apparent rate of the esterification were determined. It was demonstrated, using differential scanning calorimetry, that the ortho-ester moiety of these impurities does not completely react at typical cure conditions. It is concluded that voids formed in composites fabricated with aged monomer solution are due to gaseous decomposition products evolved by ester impurities and/or unreacted amine during elevated temperature post-cure treatment.

  20. Sunflower oil methyl ester as a diesel fuel

    SciTech Connect

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

    1983-06-01

    The University of North Dakota Engineering Experiment Station is currently engaged in research to investigate the chemistry, fuel performance, and economics of chemically modified sunflower oil for use as an emergency replacement diesel fuel Physical and chemical properties of this fuel at varying levels of refinement are being used to determine fuel properties. Engine testing carried out to date indicates that unrefined methyl ester, defined as at least 90 percent methyl ester with unreacted or partially reacted sunflower oil as the remainder, has about the same tendency to foul engines as Number 2 diesel fuel.

  1. Radiation safety

    SciTech Connect

    Benson, J.M.

    1982-09-01

    Radiation safety is rapidly becoming a major concern of every patient. Poor understanding of ionizing radiation and its effects frequently heightens anxiety. The average United States resident receives about 125 mrem of radiation per year from natural background radiation and another 120 mrem from man-made sources. The 240 million x-ray procedures performed annually contribute 90 percent of the man-made portion. It is assumed that the risks of medical radiation are outweighed by the benefits gained from the information obtained. If present in sufficiently high dosage, radiation can have harmful effects, such as induction of leukemia and thyroid malignancy. No deleterious effects have been shown to have been caused by diagnostic radiation. It is reassuring that the risks of medical radiation appear to be quite small compared with other common hazards most people face daily. Careful attention to the use of radiographic safety and protective technique will ensure the lowest possible radiation dose. The physician's discretion in ordering only appropriate and indicated x-ray films will ensure the patients are exposed to the lowest possible amount of radiation.

  2. Selective association of lipoprotein cholesteryl esters with liver plasma membranes.

    PubMed

    Rinninger, F; Jaeckle, S; Greten, H; Windler, E

    1993-02-24

    High-density lipoprotein (HDL) cholesteryl esters are taken up by hepatocytes without parallel uptake of HDL apolipoproteins. This selective uptake of HDL cholesteryl esters is mediated by a non-endocytotic mechanism. Recently, selective uptake of cholesteryl esters also from low-density lipoprotein (LDL) was demonstrated. In this study, the role of the plasma membrane in selective uptake by the liver was investigated. Plasma membranes were prepared from rat liver or from human Hep G2 hepatoma cells. Human HDL3 (d = 1.125-1.21 g/ml) was either radioiodinated or labeled with [3H]cholesteryl oleate. Human low-density lipoprotein (d = 1.019-1.05 g/ml) was labeled in its protein and in its lipid moiety as well. Labeled lipoproteins, unlabeled lipoproteins and membranes were incubated. After separation by ultracentrifugation, apparent lipoprotein particle association with membranes was determined. Plasma membranes from rat liver and Hep G2 cells bound 125I-HDL3, indicating specific HDL3 particle binding. With both types of membrane, apparent HDL3 particle association according to [3H]cholesteryl oleate-labeled HDL3 was in significant excess on that due to 125I-HDL3. This indicates selective, i.e., particle binding independent, association of cholesteryl esters with the membrane. Excess unlabeled HDL3 competed for selective association, indicating a specific process. Selective association of HDL3 cholesteryl esters was concentration-, time-, temperature-dependent; however, parameters differed from HDL3 particle binding. HDL3 was modified by nitration; this modification inhibited HDL3 particle binding in contrast to unchanged selective association. These results suggested distinct membrane sites for HDL3 particle binding and selective cholesteryl ester association. Regulation of selective association was investigated. Hep G2 cells were cholesterol-loaded or cholesterol-depleted. Cellular cholesterol-loading down-regulated selective association of HDL3 cholesteryl esters

  3. Synthesis of phosphonamidate peptides by Staudinger reactions of silylated phosphinic acids and esters.

    PubMed

    Wilkening, Ina; del Signore, Giuseppe; Hackenberger, Christian P R

    2011-01-07

    The Staudinger reaction of unprotected azido-peptides with silylated phosphinic acids and esters on the solid support offers a straightforward acid-free entry to different phosphonamidate peptide esters or acids under mild conditions in high purity and yield.

  4. Self-Motion Depending on the Physicochemical Properties of Esters as the Driving Force

    ERIC Educational Resources Information Center

    Nakata, Satoshi; Matsuo, Kyoko; Kirisaka, Junko

    2007-01-01

    The self-motion of an ester boat is investigated depending on the physicochemical properties of the surface-active substance. The results show that the ester boat moves towards the higher surface tension generating as the driving force.

  5. Self-Motion Depending on the Physicochemical Properties of Esters as the Driving Force

    ERIC Educational Resources Information Center

    Nakata, Satoshi; Matsuo, Kyoko; Kirisaka, Junko

    2007-01-01

    The self-motion of an ester boat is investigated depending on the physicochemical properties of the surface-active substance. The results show that the ester boat moves towards the higher surface tension generating as the driving force.

  6. The transition from linear to highly branched poly(β-amino ester)s: Branching matters for gene delivery

    PubMed Central

    Zhou, Dezhong; Cutlar, Lara; Gao, Yongsheng; Wang, Wei; O’Keeffe-Ahern, Jonathan; McMahon, Sean; Duarte, Blanca; Larcher, Fernando; Rodriguez, Brian J.; Greiser, Udo; Wang, Wenxin

    2016-01-01

    Nonviral gene therapy holds great promise but has not delivered treatments for clinical application to date. Lack of safe and efficient gene delivery vectors is the major hurdle. Among nonviral gene delivery vectors, poly(β-amino ester)s are one of the most versatile candidates because of their wide monomer availability, high polymer flexibility, and superior gene transfection performance both in vitro and in vivo. However, to date, all research has been focused on vectors with a linear structure. A well-accepted view is that dendritic or branched polymers have greater potential as gene delivery vectors because of their three-dimensional structure and multiple terminal groups. Nevertheless, to date, the synthesis of dendritic or branched polymers has been proven to be a well-known challenge. We report the design and synthesis of highly branched poly(β-amino ester)s (HPAEs) via a one-pot “A2 + B3 + C2”–type Michael addition approach and evaluate their potential as gene delivery vectors. We find that the branched structure can significantly enhance the transfection efficiency of poly(β-amino ester)s: Up to an 8521-fold enhancement in transfection efficiency was observed across 12 cell types ranging from cell lines, primary cells, to stem cells, over their corresponding linear poly(β-amino ester)s (LPAEs) and the commercial transfection reagents polyethyleneimine, SuperFect, and Lipofectamine 2000. Moreover, we further demonstrate that HPAEs can correct genetic defects in vivo using a recessive dystrophic epidermolysis bullosa graft mouse model. Our findings prove that the A2 + B3 + C2 approach is highly generalizable and flexible for the design and synthesis of HPAEs, which cannot be achieved by the conventional polymerization approach; HPAEs are more efficient vectors in gene transfection than the corresponding LPAEs. This provides valuable insight into the development and applications of nonviral gene delivery and demonstrates great prospect for their

  7. Radiator technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    1993-01-01

    Radiator technology is discussed in the context of the Civilian Space Technology Initiative's (CSTI's) high capacity power-thermal management project. The CSTI project is a subset of a project to develop a piloted Mars nuclear electric propulsion (NEP) vehicle. The following topics are presented in vugraph form: advanced radiator concepts; heat pipe codes and testing; composite materials; radiator design and integration; and surface morphology.

  8. Hawking radiation

    NASA Astrophysics Data System (ADS)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  9. Improved Preparation of Halopropyl Bridged Carboxylic Ortho Esters

    USDA-ARS?s Scientific Manuscript database

    Protection of a carboxylic acid function as a bridged ortho ester derivative enables the use of strongly basic conditions in the synthetic strategy because the protons, alpha to the previous carbonyl carbon, are less acidic. Protected 3-halopropionic acid can behave like an alkyl halide making them...

  10. Gold-catalysed cascade rearrangements of ynamide propargyl esters.

    PubMed

    Heffernan, Stephen J; Beddoes, James M; Mahon, Mary F; Hennessy, Alan J; Carbery, David R

    2013-03-21

    The Au(I)-catalysed rearrangement of propargylic esters formed from an ynamide has been studied. The reaction is facile, and when conducted in the presence of a reactive indole nucleophile, leads to a cascade process whereby γ-indolyl α-acyloxyenamides are formed in good yield and excellent E-stereoselectivity.

  11. Synthesis and physical properties of petroselinic based estolide esters

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

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

  13. Long-acting estrogenic responses of estradiol fatty acid esters.

    PubMed

    Vazquez-Alcantara, M A; Menjivar, M; Garcia, G A; Díaz-Zagoya, J C; Garza-Flores, J

    1989-12-01

    Estradiol esters at C-17 and C-3 with palmitic, stearic and oleic acids were chemically synthesized and then evaluated for their long-acting estrogenic responses in ovariectomized rats. The duration of the biological effects was measured after a single subcutaneous dose of 0.1 mumol of each ester and compared with those observed with 17 beta-estradiol, estradiol 3-benzoate and estradiol 17-enanthate. Vaginal citology, uterophyc action, serum gonadotropins inhibition and 17 beta-estradiol levels were measured 0, 5, 10, 20, 30 and 60 days after injection. The results disclosed that most of the estradiol derivatives evaluated exhibited a long-acting estrogenic action. However, the monoesters at C-17 showed longer effects that monoesters at C-3, while the estradiol diesters exhibited the shortest effects. In addition as shown by its low serum levels, all estradiol esters with unsaturated fatty acids show a decreased E2 absorption. The overall results indicated that esterification of E2 with long chain fatty acids provided long-acting properties to it, being higher with C-17 esters. Whether some of these compounds could be employed in substitutive endocrine therapy remains to be established.

  14. 21 CFR 556.240 - Estradiol and related esters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.240 Estradiol and related esters. No residues of estradiol... increments above the concentrations of estradiol naturally present in untreated animals: (a) In uncooked...

  15. The thermodynamics of phosphate versus phosphorothioate ester hydrolysis.

    PubMed

    Purcell, Jamie; Hengge, Alvan C

    2005-10-14

    Phosphorothioate esters are phosphate esters in which one of the nonbridging oxygen atoms has been replaced by sulfur. In the comparative hydrolysis reactions of phosphorothioate and phosphate esters, the sulfur substitution accelerates the rates of the monoesters while slowing the rates of diesters and of triesters. Previously measured enthalpies and entropies of activation for the hydrolysis reactions of the monoesters, p-nitrophenyl phosphate and p-nitrophenyl phosphorothioate, were compared to the activation parameters measured herein for the diesters, ethyl p-nitrophenyl phosphate and ethyl p-nitrophenyl phosphorothioate, and the triesters, diethyl p-nitrophenyl phosphate and diethyl p-nitrophenyl phosphorothioate. A consistent trend of a greater DeltaH++ for the phosphorothioate analogue was found in all three classes of ester. In the monoester case, a more positive DeltaS++ arising from a mechanistic difference (D(N) + A(N) for the phosphorothioate versus A(N)D(N) for the phosphate) compensates, resulting in a lower DeltaG++ for the phosphorothioate monoester. Spectroscopic investigations indicate there is no significant difference in bond order to the leaving group in phosphates, as compared to their phosphorothioate analogues, ruling this out as a contribution to the consistently higher enthalpies of activation.

  16. Ranking of aquatic toxicity of esters modelled by QSAR.

    PubMed

    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. Rat serum carboxylesterase partly hydrolyses gamma-butyrobetaine esters.

    PubMed

    Bagdoniene, Lida; Labeikyte, Danute; Kalviņs, Ivars; Borutinskaite, Veronika; Prokofjevs, Aleksandrs; Trapencieris, Pēteris; Juodka, Benediktas; Sjakste, Nikolajs

    2009-06-01

    Although described some time ago, gamma-butyrobetaine esters and related compounds have not gained much attention from researchers, and their physiological function remains obscure. Formerly we detected GBB-esterase enzymatic activity in rat blood serum using phenylated gamma-butyrobetaine as an artificial substrate of the enzyme and HPLC. The aim of the present work was to develop an assay that would enable spectrophotometric or colorimetric determination of the reaction products of GBB-esterase activity and to reveal individual proteins performing GBB-esterase activity in rat blood serum. For this purpose gamma-butyrobetaine 1-naphthyl ester was synthesised. Hydrolysis of this ester releases 1-naphthol, which increases the optical absorbance at 322 nm. We have shown that the enzymatic hydrolysis of GBB 1-naphthyl ester to 1-naphthol in rat blood serum is due to GBB-esterase activity. An attempt was done to purify the enzyme from rat blood serum. By combining DEAE Sepharose at pH 4.2 and affinity chromatography with procainamide we achieved a 68-fold enrichment of GBB-esterase activity in our preparations. Separation of fraction proteins in 2D protein electrophoresis with following mass-spectrometry indicated that GBB esterase activity in rat blood serum is performed in part by carboxylesterase.

  18. Iodine-Catalyzed Synthesis of Mixed Cellulose Esters

    USDA-ARS?s Scientific Manuscript database

    A novel method for the preparation of cellulose mixed acetate is described herein, involving the concurrent use of iodine and mixed anhydride. The method is simple, rapid, efficient, and solvent-less. With this method, cellulose mixed esters has been synthesized. ...

  19. Solvation of Esters and Ketones in Supercritical CO2.

    PubMed

    Kajiya, Daisuke; Imanishi, Masayoshi; Saitow, Ken-ichi

    2016-02-04

    Vibrational Raman spectra for the C═O stretching modes of three esters with different functional groups (methyl, a single phenyl, and two phenyl groups) were measured in supercritical carbon dioxide (scCO2). The results were compared with Raman spectra for three ketones involving the same functional groups, measured at the same thermodynamic states in scCO2. The peak frequencies of the Raman spectra of these six solute molecules were analyzed by decomposition into the attractive and repulsive energy components, based on the perturbed hard-sphere theory. For all solute molecules, the attractive energy is greater than the repulsive energy. In particular, a significant difference in the attractive energies of the ester-CO2 and ketone-CO2 systems was observed when the methyl group is attached to the ester or ketone. This difference was significantly reduced in the solute systems with a single phenyl group and was completely absent in those with two phenyl groups. The optimized structures among the solutes and CO2 molecules based on quantum chemical calculations indicate that greater attractive energy is obtained for a system where the oxygen atom of the ester is solvated by CO2 molecules.

  20. Identification of the thiol ester lipids in apolipoprotein B

    SciTech Connect

    Huang, G.; Lee, D.M.; Singh, S.

    1988-03-08

    Human plasma low-density lipoproteins of 1.032-1.043 g/mL density were totally delipidized. The reduced and carboxymethylated apolipoprotein B was incubated with 50 mM (/sup 14/C) methylamine at pH 8.5 at 30 /sup 0/C. Covalent incorporation of (/sup 14/C) methylamine was observed with concomitant generation of new sulfhydryl groups, which could be blocked with (/sup 3/H)- or (/sup 14/C)iodoacetic acid. One type of the (/sup 14/C) methylamine-modified products was separated from the protein and was found to be lipid in nature. Its R/sub f/ on thin-layer chromatography (TLC) was similar to that of the synthetic N-methyl fatty acyl amides. After purification with TLC and transesterification in 3 N methanolic HCl, methyl esters of C/sub 16/ and C/sub 18/ fatty acids at 1:1 ratio were identified by gas-liquid chromatography. The transesterification method was verified with the known N-methyl fatty acyl amides. These results suggest the presence of labile thiol ester linked palmitate and stearate in apolipoprotein B. Under mild alkaline conditions, the thiol ester bonds are broken by methylamine and form N-methyl fatty acyl amides and release new -SH groups. Intramolecular thiol ester bonds linked between cysteine side chains and acidic amino acid residues were also found present, which will be reported separately.

  1. Identification of the thiol ester linked lipids in apolipoprotein B

    SciTech Connect

    Huang, G.; Lee, D.M.; Singh, S.

    1988-03-08

    Human plasma low-density lipoproteins of 1.032-1.043 g/mL density were totally delipidized. The reduced and carboxymethylated apolipoprotein B was incubated with 50 mM (/sup 14/C)methylamine at pH 8.5 at 30 degrees C. Covalent incorporation of (/sup 14/C)methylamine was observed with concomitant generation of new sulfhydryl groups, which could be blocked with (/sup 3/H)- or (/sup 14/C)iodoacetic acid. One type of the (/sup 14/C)methylamine-modified products was separated from the protein and was found to be lipid in nature. Its Rf on thin-layer chromatography (TLC) was similar to that of the synthetic N-methyl fatty acyl amides. After purification with TLC and transesterification in 3 N methanolic HCl, methyl esters of C16 and C18 fatty acids at 1:1 ratio were identified by gas-liquid chromatography. The transesterification method was verified with the known N-methyl fatty acyl amides. These results suggest the presence of labile thiol ester linked palmitate and stearate in apolipoprotein B. Under mild alkaline conditions, the thiol ester bonds are broken by methylamine and form N-methyl fatty acyl amides and release new-SH groups. Intramolecular thiol ester bonds linked between cysteine side chains and acidic amino acid residues were also found present, which will be reported separately.

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

    PubMed

    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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Methyl esters (biodiesel) from Pachyrhizus erosus seed oil

    USDA-ARS?s Scientific Manuscript database

    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...

  4. 21 CFR 172.735 - Glycerol ester of rosin.

    Code of Federal Regulations, 2010 CFR

    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 FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN...

  5. Preparation of Jojoba Oil Ester Derivatives for Biodiesel Evaluation

    USDA-ARS?s Scientific Manuscript database

    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...

  6. Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogues

    USDA-ARS?s Scientific Manuscript database

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

  7. Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogs

    USDA-ARS?s Scientific Manuscript database

    The natural product dihydroferulic acid (DFA, 1) and the synthesized DFA methyl (4a), ethyl (4b), propyl (4c), hexyl (4d), octyl (4e), and decyl (4f) esters were examined for antifungal activity. Test fungi included Saccharomyces cerevisiae (wild type, and deletion mutants slt2' and bck1'), Aspergil...

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

    PubMed

    Lv, Xueju; Hao, Yi; Jia, Qiong

    2013-08-01

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

  9. New phenolic esters from the resinous exudate of Haplopappus taeda.

    PubMed

    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.

  10. Combining Pear Ester with Codlemone Improves Management of Codling Moth

    USDA-ARS?s Scientific Manuscript database

    Several management approaches utilizing pear ester combined with codlemone have been developed in the first 10 years after the discovery of this ripe pear fruit volatile’s kairomonal activity for larvae and both sexes of codling moth. These include a lure that consistently outperforms other high loa...

  11. Cinnamic ester derivatives from Oxalis pes-caprae (Bermuda buttercup).

    PubMed

    DellaGreca, Marina; Previtera, Lucio; Purcaro, Raffaella; Zarrelli, Armando

    2007-10-01

    Seven new cinnamic ester derivatives ( 1- 7) were isolated from a methanol extract of the fresh leaves and twigs of Oxalis pes-caprae (Bermuda buttercup). The structures of these new compounds were determined by spectroscopic data interpretation. The effects of compounds 1- 7 on the germination and growth of Lactuca sativa (lettuce) were studied.

  12. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting. (1) The chemical substance identified generically as a brominated aromatic ester (PMN P-95-1128... water. Requirements as specified in § 721.90 (a)(1), (b)(1), and (c)(1). (b) Specific requirements. The...) Recordkeeping. Recordkeeping requirements as specified in § 721.125 (a), (b), (c), (f), (g), (h), (i), and (k...

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

    ERIC Educational Resources Information Center

    Clarke, Michele; And Others

    1986-01-01

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

  14. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... emulsion defoamer. Disodium hydrogen phosphate Do. Formaldehyde Glyceryl monostearate Methyl cellulose... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylate ester copolymer coating. 175.210 Section 175.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  15. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... amount required as a preservative in emulsion defoamer. Disodium hydrogen phosphate Do. Formaldehyde... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acrylate ester copolymer coating. 175.210 Section 175.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  16. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... emulsion defoamer. Disodium hydrogen phosphate Do. Formaldehyde Glyceryl monostearate Methyl cellulose... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylate ester copolymer coating. 175.210 Section 175.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

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

    ERIC Educational Resources Information Center

    Clarke, Michele; And Others

    1986-01-01

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

  18. New bis(alkythio) fatty acid methyl esters

    USDA-ARS?s Scientific Manuscript database

    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), ...

  19. Improving Biodiesel Fuel Properties by Modifying Fatty Ester Composition

    USDA-ARS?s Scientific Manuscript database

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

  20. Conversion of cotton byproducts to mixed cellulose esters

    USDA-ARS?s Scientific Manuscript database

    Cotton byproducts, such as cotton burr and cottonseed hull, can be used as low-cost feedstock for the production of specialty chemicals. The conversion of these cellulosic byproducts into mixed cellulose esters, e.g., cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB), was stud...

  1. Synthesis and physical properties of pennycress estolides and esters

    USDA-ARS?s Scientific Manuscript database

    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...

  2. Physical proprieties of low viscosity estolide 2-ethylhexyl esters

    USDA-ARS?s Scientific Manuscript database

    Acetic- and butyric-capped oleic estolide 2-ethylhexyl (2-EH) esters were synthesized in a perchloric acid catalyzed (0.05 equiv) one-pot process from industrial 90% oleic acid and either acetic or butyric fatty acids at two different ratios. This was directly followed by the esterification process ...

  3. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection of Environment...) derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant new uses subject...) derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to reporting under this section...

  4. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection of Environment...) derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant new uses subject...) derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to reporting under this section...

  5. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection of Environment...) derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant new uses subject...) derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to reporting under this section...

  6. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection of Environment...) derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant new uses subject...) derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to reporting under this section...

  7. 40 CFR 721.6110 - Alkyldi(alkyloxyhydroxypropyl) derivative, phosphoric acid esters, potassium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) derivative, phosphoric acid esters, potassium salts. 721.6110 Section 721.6110 Protection of Environment...) derivative, phosphoric acid esters, potassium salts. (a) Chemical substance and significant new uses subject...) derivative, phosphoric acid esters, potassium salts (PMN P-91-818) is subject to reporting under this section...

  8. 40 CFR 721.10165 - Carbonotrithioic acid, bis(phenylmethyl) ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...(phenylmethyl) ester. 721.10165 Section 721.10165 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10165 Carbonotrithioic acid, bis(phenylmethyl) ester. (a) Chemical... carbonotrithioic acid, bis(phenylmethyl) ester (PMN P-08-138; CAS No.26504-29-0) is subject to reporting under this...

  9. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to reporting...

  10. 21 CFR 178.3450 - Esters of stearic and palmitic acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Esters of stearic and palmitic acids. 178.3450 Section 178.3450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... SANITIZERS Certain Adjuvants and Production Aids § 178.3450 Esters of stearic and palmitic acids. The ester...

  11. 40 CFR 721.10142 - Oxabicycloalkane carboxylic acid alkanediyl ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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) is...

  12. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168) is...

  13. 40 CFR 721.2078 - 1-Piperidinecarboxylic acid, 2-[(dichloro-hydroxy-carbomonocycle)hydrazono]-, methyl ester...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...- -, methyl ester (generic). 721.2078 Section 721.2078 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.2078 1-Piperidinecarboxylic acid, 2- -, methyl ester... generically identified as 1-piperidinecarboxylic acid, 2- -, methyl ester (PMN P-96-756) is subject to...

  14. 40 CFR 180.1277 - Dibasic esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Dibasic esters; exemption from the... Exemptions From Tolerances § 180.1277 Dibasic esters; exemption from the requirement of a tolerance. Dibasic esters (CAS Reg. No. 95481-62-2) is exempted from the requirement of a tolerance for residues when used...

  15. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Partial phosphoric acid esters of polyester resins... COMPONENTS OF COATINGS Substances for Use as Components of Coatings § 175.260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

  16. 40 CFR 180.1222 - Sucrose octanoate esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Sucrose octanoate esters; exemption... FOOD Exemptions From Tolerances § 180.1222 Sucrose octanoate esters; exemption from the requirement of... octanoate esters in or on all food commodities when used in accordance with good agricultural practices. ...

  17. 40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyaziridinyl ester of an aliphatic... Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a... generically as a polyaziridinyl ester of an aliphatic alcohol (PMN P-01-97) is subject to reporting under this...

  18. 40 CFR 721.8340 - Mono esters from 2- propenoic acid (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mono esters from 2- propenoic acid... Specific Chemical Substances § 721.8340 Mono esters from 2- propenoic acid (generic). (a) Chemical... as mono esters from 2-propenoic acid (PMN P-01-85) is subject to reporting under this section for the...

  19. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN P-04...

  20. 40 CFR 721.9965 - Fatty acids, C10-13 - branched, vinyl esters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... esters. 721.9965 Section 721.9965 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.9965 Fatty acids, C10-13 - branched, vinyl esters. (a) Chemical... acids, C10-13 - branched, vinyl esters (PMN P-97-482; CAS No. 184785-38-4) is subject to reporting under...

  1. 40 CFR 721.2900 - Substituted aminobenzoic acid ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted aminobenzoic acid ester... Specific Chemical Substances § 721.2900 Substituted aminobenzoic acid ester (generic name). (a) Chemical... acid ester (PMN P-84-951) is subject to reporting under this section for the significant new uses...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to reporting...

  3. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty...

  4. 40 CFR 721.2920 - tert-Amyl peroxy alkylene ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false tert-Amyl peroxy alkylene ester... Specific Chemical Substances § 721.2920 tert-Amyl peroxy alkylene ester (generic name). (a) Chemical... alkylene ester (PMN P-85-1180) is subject to reporting under this section for the significant new uses...

  5. 40 CFR 721.3063 - Substituted phenyl azo substituted phenyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... phenyl esters (generic name). 721.3063 Section 721.3063 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as substituted phenyl azo substituted phenyl esters (PMNs P-95...

  6. 40 CFR 721.10133 - 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxyethyl ester, homopolymer. 721.10133 Section 721.10133 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10133 2-Propenoic acid, 2-methyl, 2-hydroxyethyl ester... identified as 2-propenoic acid, 2-methyl, 2-hydroxyethyl ester, homopolymer (PMN P-07-401; CAS No. 25249-16-5...

  7. 21 CFR 178.3600 - Methyl glucoside-coconut oil ester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  9. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and...

  10. 40 CFR 721.8340 - Mono esters from 2- propenoic acid (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mono esters from 2- propenoic acid... Specific Chemical Substances § 721.8340 Mono esters from 2- propenoic acid (generic). (a) Chemical... as mono esters from 2-propenoic acid (PMN P-01-85) is subject to reporting under this section for the...

  11. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and...

  12. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and...

  13. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylated fatty acid esters of glycerol and... DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and...

  14. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and...

  15. 75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-25

    ...-2010-0429; FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of acetic acid ethenyl ester, polymer with oxirane... permissible level for residues of acetic acid ethenyl ester, polymer with oxirane on food or feed commodities...

  16. 76 FR 8895 - Polymerized Fatty Acid Esters With Aminoalcohol Alkoxylates; Exemption From the Requirement of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ... AGENCY 40 CFR Part 180 Polymerized Fatty Acid Esters With Aminoalcohol Alkoxylates; Exemption From the... acid esters with aminoalcohol alkoxylates (PFAEAA) with a minimum number average molecular weight (in... tolerance for residues of polymerized fatty acid esters with aminoalcohol alkoxylates (PFAEAA); limited to...

  17. Changes in Esters of Fatty Acids of Rhizopus arrhizus During Germination and Growth

    PubMed Central

    Hess, S. L.; Weber, D. J.; Gunasekaran, M.

    1972-01-01

    Natural esters of fatty acids of Rhizopus arrhizus Fischer increased during the first 48 hr of growth. During the 48- to 72-hr period, there was a shift in concentration from the methyl esters to the ethyl esters of fatty acids. PMID:5079078

  18. 40 CFR 721.10497 - Substituted alkyl ester, hydrolysis products with silica and substituted silane (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted alkyl ester, hydrolysis... ester, hydrolysis products with silica and substituted silane (generic). (a) Chemical substance and... alkyl ester, hydrolysis products with silica and substituted silane (PMNs P-06-276 and P-06-279)...

  19. 40 CFR 721.10497 - Substituted alkyl ester, hydrolysis products with silica and substituted silane (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted alkyl ester, hydrolysis... ester, hydrolysis products with silica and substituted silane (generic). (a) Chemical substance and... alkyl ester, hydrolysis products with silica and substituted silane (PMNs P-06-276 and P-06-279)...

  20. 40 CFR 721.10142 - Oxabicycloalkane carboxylic acid alkanediyl ester (generic).

    Code of Federal Regulations, 2010 CFR

    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) is...